A novel high-κ~ A1203/HfO2/AI203 nanolaminate charge trapping memory capacitor structure based on SiGe substrates with low interface densities is successfully fabricated and investigated. The memory capacitor exhibit...A novel high-κ~ A1203/HfO2/AI203 nanolaminate charge trapping memory capacitor structure based on SiGe substrates with low interface densities is successfully fabricated and investigated. The memory capacitor exhibits excellent program-erasable characteristics. A large memory window of ~4 V, a small leakage current density of ~2 ×10-6 Acre-2 at a gate voltage of 7V, a high charge trapping density of 1.42 × 1013 cm-2 at a working vo]tage of 4-10 V and good retention characteristics are observed. Furthermore, the programming (△ VFB = 2.8 V at 10 V for 10μs) and erasing speeds (△VFB =-1.7 V at -10 V for 10μs) of the fabricated capacitor based on SiGe substrates are significantly improved as compared with counterparts reported earlier. It is concluded that the high-κ Al2O3/HfO2/Al2O3 nanolaminate charge trapping capacitor structure based on SiGe substrates is a promising candidate for future nano-scaled nonvolatile flash memory applications.展开更多
We propose and investigate a novel metal/SiO_2/Si_3N_4/SiO_2/SiGe charge trapping flash memory structure(named as MONOS), utilizing Si Ge as the buried channel. The fabricated memory device demonstrates excellent pr...We propose and investigate a novel metal/SiO_2/Si_3N_4/SiO_2/SiGe charge trapping flash memory structure(named as MONOS), utilizing Si Ge as the buried channel. The fabricated memory device demonstrates excellent programerasable characteristics attributed to the fact that more carriers are generated by the smaller bandgap of Si Ge during program/erase operations. A flat-band voltage shift 2.8 V can be obtained by programming at +11 V for 100 us. Meanwhile, the memory device exhibits a large memory window of ~7.17 V under ±12 V sweeping voltage, and a negligible charge loss of 18% after 104 s' retention. In addition, the leakage current density is lower than 2.52 × 10^(-7) A·cm^(-2) below a gate breakdown voltage of 12.5 V. Investigation of leakage current-voltage indicates that the Schottky emission is the predominant conduction mechanisms for leakage current. These desirable characteristics are ascribed to the higher trap density of the Si_3N_4 charge trapping layer and the better quality of the interface between the SiO_2 tunneling layer and the Si Ge buried channel. Therefore, the application of the Si Ge buried channel is very promising to construct 3 D charge trapping NAND flash devices with improved operation characteristics.展开更多
The common propellants used for electric thrusters, such as xenon and krypton, are rare, expensive,and difficult to acquire. Solid iodine attracts much attention with the advantages of low cost,extensive availability,...The common propellants used for electric thrusters, such as xenon and krypton, are rare, expensive,and difficult to acquire. Solid iodine attracts much attention with the advantages of low cost,extensive availability, low vapor pressure, and ionization potential. The performance of a lowpower iodine-fed Hall thruster matched with a xenon-fed cathode is investigated across a broad range of operation conditions. Regulation of the iodine vapor's mass flow rates is stably achieved by using a temperature control method of the iodine reservoir. The thrust measurements are finished utilizing a thrust target during the tests. Results show that thrust and anode-specific impulse increase approximately linearly with the increasing iodine mass flow rate.At the nominal power of 200 W class, iodine mass flow rates are 0.62 and 0.93 mg/s, thrusts are7.19 and 7.58 m N, anode specific impulses are 1184 and 826 s, anode efficiencies are 20.8%and 14.5%, and thrust to power ratios are 35.9 and 37.9 m N/k W under the conditions of 250 V,0.8 A and 200 V, 1.0 A, respectively. The operating characteristics of iodine-fed Hall thruster are analyzed in different states. Further work on the measurements of plasma characteristics and experimental optimization will be carried out.展开更多
Background: To combine dinicopathological characteristics associated with lymph node metastasis for submucosal gastric cancer into a nomogram. Methods: We retrospectively analyzed 262 patients with submucosal gastri...Background: To combine dinicopathological characteristics associated with lymph node metastasis for submucosal gastric cancer into a nomogram. Methods: We retrospectively analyzed 262 patients with submucosal gastric cancer who underwent D2 gastrectomy between 1996 and 2012. The relationship between lymph node metastasis and clinicopathological features was statistically analyzed. With multivariate logistic regression analysis, we made a nomogram to predict the possibility of lymph node metastasis. Receiver operating characteristic (ROC) analysis was also performed to assess the predictive value of the model. Discrimination and calibration were performed using internal validation. Results: A total number of 48 (18.3%) patients with submucosal gastric cancer have pathologically lymph node metastasis. For submucosal gastric carcinoma, lymph node metastasis was associated with age, tumor location, macroscopic type, size, differentiation, histology, the existence of ulcer and lymphovascular invasion in univariate analysis (all P〈0.05). The multivariate logistic old, macroscopic type III or mixed, undifferentiated type, regression analysis identified that age _〈50 years and presence of lymphovascular invasion were independent risk factors of lymph node metastasis in submucosal gastric cancer (all P〈0.05). We constructed a predicting nomogram with all these factors for lymph node metastasis in submucosal gastric cancer with good discrimination [area under the curve (AUC) =0.844]. Internal validation demonstrated a good discrimination power that the actual probability corresponds closely with the predicted probability. Conclusions: We developed a nomogram to predict the rate of lymph node metastasis for submucosal gastric cancer. With good discrimination and internal validation, the nomogram improved individualized predictions for assisting clinicians to make appropriated treatment decision for submucosal gastric cancer patients.展开更多
BACKGROUND : Experimental animal models of intracerebral hemorrhag (ICH) are greatly needed, so the process of establishment should be ideal in hematoma formation and easy to operate. OBJECTIVE : To construct mode...BACKGROUND : Experimental animal models of intracerebral hemorrhag (ICH) are greatly needed, so the process of establishment should be ideal in hematoma formation and easy to operate. OBJECTIVE : To construct model of ICH in rats with double injection of autologous blood taken from the cut tail cut and double withdrawal of the needle (shortened as two-step injection model), and compare with those induced by single and double injections. DESIGN : A randomized controlled tria SETTING: Department of Neurology, General Hospital of Military Area Command of Chinese PLA. MATERIALS: Thirty male Wistar rats of 10 to 12 months, weighing (400±25) g, provided by the Experimental Center of Medical Animals, General Hospital of Shenyang Military Area Command of Chinese PLA, were divided randomly into 3 groups with 10 rats in each group: two-step injection group, single injection group, double injection group. METHODS : The experiment was carried out in the Department of Neurology, General Hospital of Military Area Command of Chinese PLA from March to June in 2004. Autologous blood ICH model in rats were established as follows: In the two-step injection group, 50 μL unclotted autologous blood was taken from the rat tail cut, then injected with microsyringe into the caudate nucleus, 10 μL injected at first, paused for 2 minutes, and then the rest 40 μL injected slowly and continuously within 2 minutes. After the injection, the needle was kept immovable for about 4 minutes, withdrawn 2.0 mm, again kept immovable for about 4 minute, and then removed wholly at a slow speed. In the single injection group, 50 μL unclotted tail blood was injected slowly and continuously all within 2 minutes and the needle was slowly removed;(4) In the double injection group, 10 mL blood was injected at first, paused for 2 minutes, the rest 40 μL injected evenly within 2 minutes, and then the needle was withdrawn slowly and uninterruptedly. Neurologic findings were scored in accordance with Longa's five-point scale (0-4 scores, the higher the score, the severer the neurological dysfunction). The rats were killed to remove and sections were prepared, the morphological features of hematomas were grossly observed, the maximal diameter and size of hematomas in each slice were measured with the imaging analytical system, and the volume was calculated. Meanwhile, the conveniences of the techniques were compared. MAIN OUTCOME MEASURES: The morphological features and volume of hematomas, neurologic deficit score (NDS), and the convenience of the techniques were compared. RESULTS: All the 30 rats were involved in the analysis of results without deletion. (1) Results of the morphological observation of volume of hematoma: In the two-step injection group, hematomas located in the right caudate nucleus area regularly in circular or analogously circular shape in each slice. The formation rate of hematomas in the single injection group and double injection group were lower than those in the two-step injection group [60% (6/10), 80% (8/10), 100% (10/10), P〈 0.01, 0.05]. The volume of hematomas in the single injection group and double injection group were smaller than those in the two-step injection group [(28.5±14.8), (33.4±7.4), (41.6±3.9) mm3, P〈 0.01, 0.05]. (2) NDS results: The NDS scores in the single injection group and double injection group were smaller than that in the two-step injection group (0.90±0.83, 1.30±0.78, 1.90±0.57, P〈 0.05). (3)Comparison of the convenience of the techniques: The double injection method allowed generating reproducible hematomas in rats with shortcomings that it needed autologous arterial blood from femoral artery, and precision instruments such as microinfusion pump. The two-step injection injected fresh unclotting blood taken directly from the tail cut with microsyringe into the rat brain, and it has the advantages of easy operation, no influence on the activity of thrombase, shorter duration for model establishment, and higher rate of hematoma formation, which could generate ideal and economical models of ICH. The two-step injection induced hemotoma regularly in circular or analogously circular shape in each slice, but those induced by single and double injections were mostly in strip or fusiform shapes and extending along the needle tracks or into the ventricle or subarachnoid space. CONCLUSION : The autologous blood ICH model induced by the two-step injection method is a reproducible and reliable one in regular shape, which is better than those induced by double and single injections.展开更多
We present a conceptual configuration of a high-temperature superconducting(HTS)magnet made from REBCO(Re=Rare Earth,B=Barium,C=Copper,O=Oxide)annular plates,called a Bitter-like HTS magnet,which can operate in pe...We present a conceptual configuration of a high-temperature superconducting(HTS)magnet made from REBCO(Re=Rare Earth,B=Barium,C=Copper,O=Oxide)annular plates,called a Bitter-like HTS magnet,which can operate in persistent current mode without joint resistance and can be excited by a flux pump and without current leads and a persistent power supply.An REBCO annular magnet which can generate 1.5 T corresponding to the operating current density 80%of critical current density of the magnet at an operating temperature of65 K is conceptually designed.Then the thermal stability of the magnet is numerically simulated by Comsol software.Whein a piece of RBCO annular plate quenches,the maximum released energy is its stored energy because each REBCO annular plate in the Bitter-like magnet is in parallel.To calculate the stored energy in the REBCO annular plate,the inductance of every annular plate,including self-inductance and mutual inductance,is calculated.Compared with the minimum quench energy(MQE)and stored energy in one REBCO annular plate,the stored energy in one REBCO annular plate is always smaller than the MQE,and the REBCO annular plate will not be damaged even though the stored energy in the REBCO annular plate is fully released,which indicates that this 1.5 T Bitter-like magnet has the property of self-protection.展开更多
Flash floods are one of the most dangerous natural disasters,especially in hilly terrain,causing loss of life,property,and infrastructures and sudden disruption of traffic.These types of floods are mostly associated w...Flash floods are one of the most dangerous natural disasters,especially in hilly terrain,causing loss of life,property,and infrastructures and sudden disruption of traffic.These types of floods are mostly associated with landslides and erosion of roads within a short time.Most of Vietnamis hilly and mountainous;thus,the problem due to flash flood is severe and requires systematic studies to correctly identify flood susceptible areas for proper landuse planning and traffic management.In this study,three Machine Learning(ML)methods namely Deep Learning Neural Network(DL),Correlation-based FeatureWeighted Naive Bayes(CFWNB),and Adaboost(AB-CFWNB)were used for the development of flash flood susceptibility maps for hilly road section(115 km length)of National Highway(NH)-6 inHoa Binh province,Vietnam.In the proposedmodels,88 past flash flood events were used together with 14 flash floods affecting topographical and geo-environmental factors.The performance of themodels was evaluated using standard statisticalmeasures including Receiver Operating Characteristic(ROC)Curve,Area Under Curve(AUC)and Root Mean Square Error(RMSE).The results revealed that all the models performed well(AUC>0.80)in predicting flash flood susceptibility zones,but the performance of the DL model is the best(AUC:0.972,RMSE:0.352).Therefore,the DL model can be applied to develop an accurate flash flood susceptibility map of hilly terrain which can be used for proper planning and designing of the highways and other infrastructure facilities besides landuse management of the area.展开更多
Objective To evaluate the sensitivity and specificity of body mass index (BMI), waist circumference (WC) and waist-to-hip ratio (WHR) measurements in diagnosing abdominal visceral obesity. Methods BMI, WC, and WHR wer...Objective To evaluate the sensitivity and specificity of body mass index (BMI), waist circumference (WC) and waist-to-hip ratio (WHR) measurements in diagnosing abdominal visceral obesity. Methods BMI, WC, and WHR were assessed in 690 Chinese adults (305 men and 385 women) and compared with magnetic resonance imaging (MRI) measurements of abdominal visceral adipose tissue (VA). Receiver operating characteristic (ROC) curves were generated and used to determine the threshold point for each anthropometric parameter. Results 1) MRI showed that 61.7% of overweight/obese individuals (BMI≥25 kg/m2) and 14.2% of normal weight (BMI<25 kg/m2) individuals had abdominal visceral obesity (VA≥100 cm2). 2) VA was positively correlated with each anthropometric variable, of which WC showed the highest correlation (r=0.73-0.77, P<0.001). 3) The best cut-off points for assessing abdominal visceral obesity were as followed: BMI of 26 kg/m2, WC of 90 cm, and WHR of 0.93, with WC being the most sensitive and specific factor. 4) Among subjects with BMI≥28 kg/m2 or WC≥95 cm, 95% of men and 90% of women appeared to have abdominal visceral obesity. Conclusion Measurements of BMI, WC, and WHR can be used in the prediction of abdominal visceral obesity, of which WC was the one with better accuracy.展开更多
BACKGROUND: The various combination of multiphase enhancement multislice spiral CT (MSCT) makes the diagno- sis of a small hepatocellular carcinoma (sHCC) on the back- ground of liver cirrhosis possible. This stu...BACKGROUND: The various combination of multiphase enhancement multislice spiral CT (MSCT) makes the diagno- sis of a small hepatocellular carcinoma (sHCC) on the back- ground of liver cirrhosis possible. This study was to explore whether the combination of MSCT enhancement scan and alpha-fetoprotein (AFP) level ficiency for sHCC. could increase the diagnostic ef- METHODS: This study included 35 sHCC patients and 52 cir- rhotic patients without image evidence of HCC as a control group. The diagnoses were made by three radiologists em- ploying a 5-point rating scale, with postoperative pathologic results as the gold standard. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the diag- nostic value of the three MSCT combination modes (arterial phase+portal-venous phase, arterial phase+delayed phase, arterial phase+portal-venous phase+delayed phase) and AFP levels for sHCC on the background of liver cirrhosis. RESULTS: The area under ROC curve (AUC), sensitivity, and specificity of the combination of arterial phase+portal- venous phase+delayed phase were 0.93, 93%, and 82%, respectively. The average AUC of the arterial phase+portal- venous phase+delayed phase combination was significantly greater than that of the arterial phase+portal-venous phase (AUC=0.84, P=0.01) and arterial phase+delayed phase (AUC=0.85, P=0.03). Arterial phase+portal-venous phase had a smaller AUC (0.84) than arterial phase+delayed phase (0.85), but the difference was insignificant (P=0.15). After combining MSCT enhancement scan with AFP, the AUC, sensitivity, and specificity were 0.95, 94%, and 83%, respectively, indicating a greatly increased diagnostic efficiency for sHCC. CONCLUSIONS: The combination of AFP and 3 phases MSCT enhancement scan could increase the diagnostic efficiency for sHCC on the background of liver cirrhosis. The application of ROC curve analysis has provided a new method and reference in HCC diagnosis.展开更多
BACKGROUND Hepatitis B virus (HBV) infection is the primary cause of hepatitis with chronic HBV infection,which may develop into liver fibrosis,cirrhosis and hepatocellular carcinoma.Detection of early-stage fibrosis ...BACKGROUND Hepatitis B virus (HBV) infection is the primary cause of hepatitis with chronic HBV infection,which may develop into liver fibrosis,cirrhosis and hepatocellular carcinoma.Detection of early-stage fibrosis related to HBV infection is of great clinical significance to block the progression of liver lesion.Direct liver biopsy is regarded as the gold standard to detect and assess fibrosis;however,this method is invasive and prone to clinical sampling error.In order to address these issues,we attempted to find more convenient and effective serum markers for detecting HBV-induced early-stage liver fibrosis.AIM To investigate serum N-glycan profiling related to HBV-induced liver fibrosis and verify multiparameter diagnostic models related to serum N-glycan changes.METHODS N-glycan profiles from the sera of 432 HBV-infected patients with liver fibrosis were analyzed.Significant changed N-glycan levels (peaks)(P <0.05) in differentfibrosis stages were selected in the modeling group,and multiparameter diagnostic models were established based on changed N-glycan levels by logistic regression analysis.The receiver operating characteristic (ROC) curve analysis was performed to evaluate diagnostic efficacy of N-glycans models.These models were then compared with the aspartate aminotransferase to platelet ratio index (APRI),fibrosis index based on the four factors (FIB-4),glutamyltranspeptidase platelet albumin index (S index),GlycoCirrho-test,and GlycoFibro-test.Furthermore,we combined multiparameter diagnostic models with alanine aminotransferase (ALT) and platelet (PLT) tests and compared their diagnostic power.In addition,the diagnostic accuracy of N-glycan models was also verified in the validation group of patients.RESULTS Multiparameter diagnostic models constructed based on N-glycan peak 1,3,4and 8 could distinguish between different stages of liver fibrosis.The area under ROC curves (AUROCs) of Model A and Model B were 0.890 and 0.752,respectively differentiating fibrosis F0-F1 from F2-F4,and F0-F2 from F3-F4,and surpassing other serum panels.However,AUROC (0.747) in Model C used for the diagnosis of F4 from F0-F3 was lower than AUROC (0.795) in FIB-4.In combination with ALT and PLT,the multiparameter models showed better diagnostic power (AUROC=0.912,0.829,0.885,respectively) when compared with other models.In the validation group,the AUROCs of the three combined models (0.929,0.858,and 0.867,respectively) were still satisfactory.We also applied the combined models to distinguish adjacent fibrosis stages of 432patients (F0-F1/F2/F3/F4),and the AUROCs were 0.917,0.720 and 0.785.CONCLUSION Multiparameter models based on serum N-glycans are effective supplementary markers to distinguish between adjacent fibrosis stages of patients caused by HBV,especially in combination with ALT and PLT.展开更多
BACKGROUND:The study aimed to evaluate the predictive role of interleukin-6(IL-6)and chronic obstructive pulmonary disease(COPD)assessment test(CAT)score in mechanical ventilation(MV)in COPD patients at the acute exac...BACKGROUND:The study aimed to evaluate the predictive role of interleukin-6(IL-6)and chronic obstructive pulmonary disease(COPD)assessment test(CAT)score in mechanical ventilation(MV)in COPD patients at the acute exacerbation stage in the emergency department(ED).METHODS:For a one-year period,among adult patients in the ED who met the criteria of acute exacerbation of COPD,158 who received MV within 48 hours after admission were compared to 294 who didn't require MV within the same period after admission.IL-6 level and CAT score were compared between the two groups.The predicted value of IL-6 and CAT score was assessed by logistic regression analysis and a receiver operating characteristic(ROC)curve.RESULTS:The IL-6 and CAT scores in the 158 MV patients were much higher than those without.IL-6 and CAT scores were independent predictors of MV within 48 hours using logistic regression analysis(IL-6:odds ratio[OR]1.053,95%confidence interval[CI]1.039–1.067,P<0.001;CAT score:OR 1.122,95%CI 1.086–1.159,P<0.001).The combination of IL-6 and CAT scores(area under ROC curve[AUC]0.826,95%CI 0.786–0.866,P<0.001)improved the accuracy of predicting MV within 48 hours when compared with IL-6(AUC 0.752,95%CI 0.703–0.800,P<0.001)and CAT scores alone(AUC 0.739,95%CI 0.692–0.786,P<0.001).The sensitivity and specificity were 69.6%,74.1%,75.32%and 63.6%,respectively.CONCLUSION:The combined of IL-6 and CAT scores is useful for evaluating the risk of COPD patients at acute exacerbation in ED,and can provide a predictive value for MV or not within 48 hours.展开更多
AIM: To study the expression of β-catenin in esophageal squamous cell carcinoma (ESCC) at stage T2-3N0M0 and its relation with the prognosis of ESCC patients. METHODS: Expression of β-catenin in 227 ESCC speci-mens ...AIM: To study the expression of β-catenin in esophageal squamous cell carcinoma (ESCC) at stage T2-3N0M0 and its relation with the prognosis of ESCC patients. METHODS: Expression of β-catenin in 227 ESCC speci-mens was detected by immunohistochemistry (IHC). A reproducible semi-quantitative method which takes both staining percentage and intensity into account was applied in IHC scoring, and receiver operating char-acteristic curve analysis was used to select the cut-off score for high or low IHC reactivity. Then, correlation of β-catenin expression with clinicopathological features and prognosis of ESCC patients was determined. RESULTS: No significant correlation was observed between β-catenin expression and clinicopathological parameters in terms of gender, age, tumor size, tumor grade, tumor location, depth of invasion and pathologi-cal stage. The Kaplan-Meier survival curve showed that the up-regulated expression of β-catenin indicated a poorer post-operative survival rate of ESCC patients at stage T2-3N0M0 (P = 0.004), especially of those with T3 lesions (P = 0.014) or with stage ⅡB diseases (P = 0.007). Multivariate analysis also confirmed that β-catenin was an independent prognostic factor for the overall survival rate of ESCC patients at stage T2-3N0M0 (relative risk = 1.642, 95% CI: 1.159-2.327, P = 0.005). CONCLUSION: Elevated β-catenin expression level may be an adverse indicator for the prognosis of ESCC patients at stage T2-3N0M0, especially for those with T3 lesions or stage ⅡB diseases.展开更多
BACKGROUND Serum gastrin-17(G-17),pepsinogen I(PGI),and pepsinogen II(PGII)concentrations regulate gastric acid secretion,and hypersecretion of gastric acid increases the risks of peptic ulcer and upper gastrointestin...BACKGROUND Serum gastrin-17(G-17),pepsinogen I(PGI),and pepsinogen II(PGII)concentrations regulate gastric acid secretion,and hypersecretion of gastric acid increases the risks of peptic ulcer and upper gastrointestinal bleeding.These associations suggest that serum G-17,PGI,and(or)PGII may predict gastrointestinal bleeding risk among peptic ulcer patients.AIM To evaluate the efficacies of serum G-17,PGI,PGII,and PGI/PGII ratio(PGR)for predicting upper gastrointestinal bleeding among peptic ulcer patients.METHODS A total of 199 patients diagnosed with peptic ulcer confirmed by gastroscopy and positivity for Helicobacter pylori by the 14C-urea breath test were recruited,including 107 patients with simple peptic ulcer and 92 cases complicated by upper gastrointestinal bleeding.Serum PGI,PGII,G-17,and PGR were measured by immune methods and compared between bleeding and non-bleeding groups by univariate analysis.The specificity and sensitivity of PGs and G-17 for evaluating upper gastrointestinal bleeding risk were then assessed by constructing receiver operating characteristic(ROC)curves.RESULTS Serum G-17 was significantly higher among peptic ulcer patients with upper gastrointestinal bleeding compared to simple peptic ulcer patients(25.34±14.29 vs 8.84±8.03 pmol/L,t=9.822,P<0.01),whereas serum PGI,PGII,and PGR did not differ significantly between bleeding and non-bleeding groups(all P>0.05).The risk of bleeding was significantly higher among peptic ulcer patients with elevated serum G-17(>15 pmol/L)compared to patients with normal or low serum G-17(73.2%vs 27.4%,χ2=40.72,P<0.01).The area under the ROC curve for serum G-17 was 0.866±0.024,and a cut-off of 9.86 pmol/L yielded 90.2%sensitivity and 68.2%specificity for distinguishing peptic ulcer with and without upper gastrointestinal bleeding.CONCLUSION Serum G-17 is significantly upregulated in peptic ulcer patients and higher levels are predictive of upper gastrointestinal bleeding.Conversely,serum PGI,PGII,and PGR have no predictive value.Further prospective studies are warranted to examine if high G-17 can be used to assess risk of bleeding prior to onset.展开更多
Landslide is considered as one of the most severe threats to human life and property in the hilly areas of the world.The number of landslides and the level of damage across the globe has been increasing over time.Ther...Landslide is considered as one of the most severe threats to human life and property in the hilly areas of the world.The number of landslides and the level of damage across the globe has been increasing over time.Therefore,landslide management is essential to maintain the natural and socio-economic dynamics of the hilly region.Rorachu river basin is one of the most landslide-prone areas of the Sikkim selected for the present study.The prime goal of the study is to prepare landslide susceptibility maps(LSMs)using computer-based advanced machine learning techniques and compare the performance of the models.To properly understand the existing spatial relation with the landslide,twenty factors,including triggering and causative factors,were selected.A deep learning algorithm viz.convolutional neural network model(CNN)and three popular machine learning techniques,i.e.,random forest model(RF),artificial neural network model(ANN),and bagging model,were employed to prepare the LSMs.Two separate datasets including training and validation were designed by randomly taken landslide and nonlandslide points.A ratio of 70:30 was considered for the selection of both training and validation points.Multicollinearity was assessed by tolerance and variance inflation factor,and the role of individual conditioning factors was estimated using information gain ratio.The result reveals that there is no severe multicollinearity among the landslide conditioning factors,and the triggering factor rainfall appeared as the leading cause of the landslide.Based on the final prediction values of each model,LSM was constructed and successfully portioned into five distinct classes,like very low,low,moderate,high,and very high susceptibility.The susceptibility class-wise distribution of landslides shows that more than 90%of the landslide area falls under higher landslide susceptibility grades.The precision of models was examined using the area under the curve(AUC)of the receiver operating characteristics(ROC)curve and statistical methods like root mean square error(RMSE)and mean absolute error(MAE).In both datasets(training and validation),the CNN model achieved the maximum AUC value of 0.903 and 0.939,respectively.The lowest value of RMSE and MAE also reveals the better performance of the CNN model.So,it can be concluded that all the models have performed well,but the CNN model has outperformed the other models in terms of precision.展开更多
AIM To evaluate the efficacy of peripheral blood concentrations of angiopoietins(Ang) as cirrhosis biomarkers of chronic hepatitis C(CHC).METHODS Ang1 and Ang2 serum levels were measured by enzyme-linked immunosorbent...AIM To evaluate the efficacy of peripheral blood concentrations of angiopoietins(Ang) as cirrhosis biomarkers of chronic hepatitis C(CHC).METHODS Ang1 and Ang2 serum levels were measured by enzyme-linked immunosorbent assays(ELISA) in samples from 179 cirrhotic and non-cirrhotic CHC patients, classified according to the METAVIR system.Groups were compared by non-parametric MannWhitney U test. Subsequently, the association of peripheral concentrations of angiopoietins with the stage of fibrosis was analyzed using Spearman correlation test. Finally, the accuracy, sensitivity and specificity of circulating angiopoietins for cirrhosis diagnosis were determined by the study of the respective area under the curve of receiver operator characteristics(AUC-ROC).RESULTS Peripheral blood concentrations of Ang1 and Ang2 in CHC patients were significantly related to fibrosis. While Ang1 was decreased in cirrhotic subjects compared to non-cirrhotic(P < 0.0001), Ang2 was significantly increased as CHC progressed to the end stage of liver disease(P < 0.0001). Consequently, Ang2/Ang1 ratio was notably amplified and significantly correlated with fibrosis(P < 0.0001). Interestingly, the individual performance of each angiopoietin for the diagnosis of cirrhosis reached notable AUC-ROC values(above 0.7, both), but the Ang2/Ang1 ratio was much better(AUC-ROC = 0.810) and displayed outstanding values of sensitivity(71%), specificity(84%) and accuracy(82.1%) at the optimal cut-off(10.33). Furthermore, Ang2/Ang1 ratio improved the performance of many other previously described biomarkers or scores of liver cirrhosis in CHC.CONCLUSION Ang2/Ang1 ratio might constitute a useful tool for monitoring the progression of chronic liver disease towards cirrhosis and play an important role as therapeutic target.展开更多
Mixed traffic flow composed of autos and non-autos widely exists in developing countries and areas. To investigate the operational characteristics of the mixed traffic flow consisting of vehicles in different types (...Mixed traffic flow composed of autos and non-autos widely exists in developing countries and areas. To investigate the operational characteristics of the mixed traffic flow consisting of vehicles in different types (large vehicles, cars, and bicycles), we develop a cellular automaton model to repli- cate the travel behaviors on a bi-directional road segment with respect to the physical and mechanic features of different vehicle types. By implementing the essential parameters calibrated through the field data collection, a numerical study is carried out considering the variation in volume, density, and velocity with different compositions of mixed traffic flows. The primary findings include: the average ve- locity of traffic flow and total volume decrease 60% and 30% after incorporating 10% bicycles, respectively; the phenomenon of double-summit in terms bicycle is beyond 60 % ; the maximal total volume higher than 10 %. of the total volume appears when the proportion of starts to recover when the proportion of bicycle is展开更多
BACKGROUND Quantitative hepatitis B core-related antigen(qHBcrAg)has a better correlation with intrahepatic hepatitis B virus(HBV)covalently closed circular DNA(cccDNA)than HBV DNA or hepatitis B e antigen(HBeAg),but ...BACKGROUND Quantitative hepatitis B core-related antigen(qHBcrAg)has a better correlation with intrahepatic hepatitis B virus(HBV)covalently closed circular DNA(cccDNA)than HBV DNA or hepatitis B e antigen(HBeAg),but data are still lacking for its clinical application.AIM The aim was to investigate serum qHBcrAg levels in patients with chronic hepatitis B and assess the correlation of serum qHBcrAg with pregenomic RNA(pgRNA),cccDNA,and HBeAg seroconversion.METHODS This study was a secondary analysis of patients who underwent percutaneous liver biopsy between July 2014 and June 2019 in two multicenter randomized controlled clinical trials of peginterferon vs nucleos(t)ide analog(NUC)-based therapy(NCT03509688 and NCT03546530).Serum qHBcrAg,pgRNA,HBV DNA,hepatitis B core antigen,HBeAg,liver cccDNA,and HBV DNA were measured.The correlations of serum qHBcrAg with other biomarkers were analyzed.RESULTS A total of 139 patients were included.The mean qHBcrAg levels were 5.32±1.18 log10 U/mL at baseline and decreased during treatment(all P<0.0001).Serum qHBcrAg levels were positively correlated with pgRNA(r=0.597,P<0.0001)and cccDNA(r=0.527,P<0.0001)levels.The correlation of serum qHBcrAg level and intrahepatic HBV DNA levels at baseline was weak but significant(r=0.399,P<0.0001).HBcrAg predicted HBeAg seroconversion,with areas under the receiver operating characteristics curve of 0.788 at 24 wk and 0.825 at 48 wk.Log HBcrAg at wk 24 and 48 was independently associated with HBeAg seroconversion[odds ratio(OR)=2.402,95%confidence interval(CI):1.314-4.391,P=0.004;OR=3.587,95%CI:1.315-9.784,P=0.013].CONCLUSION Serum HBcrAg levels were correlated with HBV virological markers and could be used to predict HBeAg seroconversion.展开更多
BACKGROUND Autism is the most common clinical developmental disorder in children.The childhood autism rating scale(CARS)and autistic autism behavior checklist(ABC)are the most commonly used assessment scales for diagn...BACKGROUND Autism is the most common clinical developmental disorder in children.The childhood autism rating scale(CARS)and autistic autism behavior checklist(ABC)are the most commonly used assessment scales for diagnosing autism.However,the diagnostic validations and the corresponding cutoffs for CARS and ABC in individuals with suspected autism spectrum disorder(ASD)remain unclear.Furthermore,for suspected ASD in China,it remains unclear whether CARS is a better diagnostic tool than ABC.Also unclear is whether the current cutoff points for ABC and CARS are suitable for the accurate diagnosis of ASD.AIM To investigate the diagnostic validity of CARS and ABC based on a large Chinese sample.METHODS A total of 591 outpatient children from the ASD Unit at Beijing Children’s Hospital between June and November 2019 were identified.First,the Clancy autism behavior scale(CABS)was used to screen out suspected autism from these children.Then,each suspected ASD was evaluated by CARS and ABC.Receiver operating characteristic(ROC)curve analysis was used to compare diagnostic validations.We also calculated the area under the curve(AUC)for both CARS and ABC.RESULTS We found that the Cronbach alpha coefficients of CARS and ABC were 0.772 and 0.426,respectively.Therefore,the reliability of the CARS was higher than that of the ABC.In addition,we found that the correlation between CARS and CABS was 0.732.Next,we performed ROC curve analysis for CARS and ABC,which yielded AUC values of 0.846 and 0.768,respectively.The cutoff value,which is associated with the maximum Youden index,is usually applied as a decision threshold.We found that the cutoff values of CARS and ABC were 34 and 67,respectively.CONCLUSION This result indicated that CARS is superior to ABC in the Chinese population with suspected ASD.展开更多
BACKGROUND Silicosis is a type of chronic pulmonary fibrosis caused by long-term inhalation of silica dust particles.There has been no ideal biomarker for the diagnosis and differential diagnosis of silicosis until no...BACKGROUND Silicosis is a type of chronic pulmonary fibrosis caused by long-term inhalation of silica dust particles.There has been no ideal biomarker for the diagnosis and differential diagnosis of silicosis until now.Studies have found that elevated neuron-specific enolase(NSE)concentration in the serum of silicosis patients is helpful for diagnosis and severity assessment of the disease.However,the number of cases in these studies was not enough to arouse attention.AIM To investigate the clinical significance of serum NSE in the diagnosis and staging of silicosis.METHODS From January 2017 to June 2019,326 cases of silicosis confirmed in Quanzhou First Hospital Affiliated to Fujian Medical University were included in the silicosis group.A total of 328 healthy individuals or medical patients without silicosis were included in the control group.Serum NSE concentrations of all subjects were determined by electrochemical luminescence.RESULTS There were no significant differences in sex,age,smoking index and complications between the silicosis and control groups.The mean serum NSE concentration was 26.57±20.95 ng/mL in the silicosis group and 12.42±2.68 ng/mL in the control group.The difference between the two groups was significant(U=15187,P=0.000).Among the 326 patients with silicosis,103 had stage I silicosis,and the mean serum NSE concentration was 15.55±6.23 ng/mL.The mean serum NSE concentration was 21.85±12.05 ng/mL in 70 patients with stage II silicosis.The mean serum NSE concentration was 36.14±25.72 ng/mL in 153 patients with stage III silicosis.Kruskal-Wallis H test suggested that the difference in serum NSE concentration in silicosis patients in the three groups was significant(H=130.196,P=0.000).Receiver operating characteristic curve analysis indicated that the area under the curve was 0.858(95%confidence interval:0.828-0.888;P=0.000).When the NSE concentration was 15.82 ng/mL,the Jorden index was the largest,the sensitivity was 72%,and the specificity was 90%.CONCLUSION Serum NSE concentration may be a promising biomarker for the diagnosis and assessment of severity of silicosis.展开更多
BACKGROUND For lung adenocarcinoma with epidermal growth factor receptor(EGFR)gene mutation,small molecule tyrosine kinase inhibitors are more effective.Some patients could not obtain enough histological specimens for...BACKGROUND For lung adenocarcinoma with epidermal growth factor receptor(EGFR)gene mutation,small molecule tyrosine kinase inhibitors are more effective.Some patients could not obtain enough histological specimens for EGFR gene mutation detection.Specific imaging features can predict EGFR mutation status to a certain extent.AIM To assess the associations of EGFR mutations with high-resolution computerized tomography(HRCT)features in ground-glass nodular lung adenocarcinoma.METHODS This study retrospectively assessed patients with ground-glass nodular lung adenocarcinoma diagnosed between January 2011 and March 2017.EGFR gene mutations in exons 18-21 were detected.The patients were classified into mutant EGFR and wild-type groups,and general data and HRCT image characteristics were assessed.RESULTS Among 98 patients,31(31.6%)and 67(68.4%)had mutated and wild-type EGFR in exons 18-21,respectively.Gender,age,smoking history,location of lesions,morphology,edges,borders,pleural indentations,and associations of nodules with bronchus and blood vessels were comparable in both groups(all P>0.05).Patients with mutant EGFR had larger nodules than those with the wild-type(17.19±6.79 and 14.37±6.30 mm,respectively;P=0.047).Meanwhile,the vacuole/honeycomb sign was more frequent in the mutant EGFR group(P=0.011).The logistic regression prediction model included the combination of nodule size and vacuole/honeycomb sign(OR=1.120,95%CI:1.023-1.227,P=0.014)revealed a sensitivity of 83.9%,a specificity of 52.2%and an AUC of 0.698(95%CI:0.589-0.806;P=0.002).CONCLUSION Nodule size and vacuole/honeycomb features could independently predict EGFR mutation status in ground-glass nodular lung adenocarcinoma.展开更多
基金Supported by the National Science and Technology Major Project of China under Grant No 2013ZX02303007the National Key Research and Development Program of China under Grant No 2016YFA0301701the Youth Innovation Promotion Association of the Chinese Academy of Sciences under Grant No 2016112
文摘A novel high-κ~ A1203/HfO2/AI203 nanolaminate charge trapping memory capacitor structure based on SiGe substrates with low interface densities is successfully fabricated and investigated. The memory capacitor exhibits excellent program-erasable characteristics. A large memory window of ~4 V, a small leakage current density of ~2 ×10-6 Acre-2 at a gate voltage of 7V, a high charge trapping density of 1.42 × 1013 cm-2 at a working vo]tage of 4-10 V and good retention characteristics are observed. Furthermore, the programming (△ VFB = 2.8 V at 10 V for 10μs) and erasing speeds (△VFB =-1.7 V at -10 V for 10μs) of the fabricated capacitor based on SiGe substrates are significantly improved as compared with counterparts reported earlier. It is concluded that the high-κ Al2O3/HfO2/Al2O3 nanolaminate charge trapping capacitor structure based on SiGe substrates is a promising candidate for future nano-scaled nonvolatile flash memory applications.
基金Supported by the National Science and Technology Major Project of China under Grant No 2013ZX02303007the National Key Research and Development Program of China under Grant No 2016YFA0301701the Youth Innovation Promotion Association of the Chinese Academy of Sciences under Grant No 2016112
文摘We propose and investigate a novel metal/SiO_2/Si_3N_4/SiO_2/SiGe charge trapping flash memory structure(named as MONOS), utilizing Si Ge as the buried channel. The fabricated memory device demonstrates excellent programerasable characteristics attributed to the fact that more carriers are generated by the smaller bandgap of Si Ge during program/erase operations. A flat-band voltage shift 2.8 V can be obtained by programming at +11 V for 100 us. Meanwhile, the memory device exhibits a large memory window of ~7.17 V under ±12 V sweeping voltage, and a negligible charge loss of 18% after 104 s' retention. In addition, the leakage current density is lower than 2.52 × 10^(-7) A·cm^(-2) below a gate breakdown voltage of 12.5 V. Investigation of leakage current-voltage indicates that the Schottky emission is the predominant conduction mechanisms for leakage current. These desirable characteristics are ascribed to the higher trap density of the Si_3N_4 charge trapping layer and the better quality of the interface between the SiO_2 tunneling layer and the Si Ge buried channel. Therefore, the application of the Si Ge buried channel is very promising to construct 3 D charge trapping NAND flash devices with improved operation characteristics.
基金supported by Joint Fund for Equipment Preresearch and Aerospace Science and Technology (No. 6141B061203)。
文摘The common propellants used for electric thrusters, such as xenon and krypton, are rare, expensive,and difficult to acquire. Solid iodine attracts much attention with the advantages of low cost,extensive availability, low vapor pressure, and ionization potential. The performance of a lowpower iodine-fed Hall thruster matched with a xenon-fed cathode is investigated across a broad range of operation conditions. Regulation of the iodine vapor's mass flow rates is stably achieved by using a temperature control method of the iodine reservoir. The thrust measurements are finished utilizing a thrust target during the tests. Results show that thrust and anode-specific impulse increase approximately linearly with the increasing iodine mass flow rate.At the nominal power of 200 W class, iodine mass flow rates are 0.62 and 0.93 mg/s, thrusts are7.19 and 7.58 m N, anode specific impulses are 1184 and 826 s, anode efficiencies are 20.8%and 14.5%, and thrust to power ratios are 35.9 and 37.9 m N/k W under the conditions of 250 V,0.8 A and 200 V, 1.0 A, respectively. The operating characteristics of iodine-fed Hall thruster are analyzed in different states. Further work on the measurements of plasma characteristics and experimental optimization will be carried out.
文摘Background: To combine dinicopathological characteristics associated with lymph node metastasis for submucosal gastric cancer into a nomogram. Methods: We retrospectively analyzed 262 patients with submucosal gastric cancer who underwent D2 gastrectomy between 1996 and 2012. The relationship between lymph node metastasis and clinicopathological features was statistically analyzed. With multivariate logistic regression analysis, we made a nomogram to predict the possibility of lymph node metastasis. Receiver operating characteristic (ROC) analysis was also performed to assess the predictive value of the model. Discrimination and calibration were performed using internal validation. Results: A total number of 48 (18.3%) patients with submucosal gastric cancer have pathologically lymph node metastasis. For submucosal gastric carcinoma, lymph node metastasis was associated with age, tumor location, macroscopic type, size, differentiation, histology, the existence of ulcer and lymphovascular invasion in univariate analysis (all P〈0.05). The multivariate logistic old, macroscopic type III or mixed, undifferentiated type, regression analysis identified that age _〈50 years and presence of lymphovascular invasion were independent risk factors of lymph node metastasis in submucosal gastric cancer (all P〈0.05). We constructed a predicting nomogram with all these factors for lymph node metastasis in submucosal gastric cancer with good discrimination [area under the curve (AUC) =0.844]. Internal validation demonstrated a good discrimination power that the actual probability corresponds closely with the predicted probability. Conclusions: We developed a nomogram to predict the rate of lymph node metastasis for submucosal gastric cancer. With good discrimination and internal validation, the nomogram improved individualized predictions for assisting clinicians to make appropriated treatment decision for submucosal gastric cancer patients.
文摘BACKGROUND : Experimental animal models of intracerebral hemorrhag (ICH) are greatly needed, so the process of establishment should be ideal in hematoma formation and easy to operate. OBJECTIVE : To construct model of ICH in rats with double injection of autologous blood taken from the cut tail cut and double withdrawal of the needle (shortened as two-step injection model), and compare with those induced by single and double injections. DESIGN : A randomized controlled tria SETTING: Department of Neurology, General Hospital of Military Area Command of Chinese PLA. MATERIALS: Thirty male Wistar rats of 10 to 12 months, weighing (400±25) g, provided by the Experimental Center of Medical Animals, General Hospital of Shenyang Military Area Command of Chinese PLA, were divided randomly into 3 groups with 10 rats in each group: two-step injection group, single injection group, double injection group. METHODS : The experiment was carried out in the Department of Neurology, General Hospital of Military Area Command of Chinese PLA from March to June in 2004. Autologous blood ICH model in rats were established as follows: In the two-step injection group, 50 μL unclotted autologous blood was taken from the rat tail cut, then injected with microsyringe into the caudate nucleus, 10 μL injected at first, paused for 2 minutes, and then the rest 40 μL injected slowly and continuously within 2 minutes. After the injection, the needle was kept immovable for about 4 minutes, withdrawn 2.0 mm, again kept immovable for about 4 minute, and then removed wholly at a slow speed. In the single injection group, 50 μL unclotted tail blood was injected slowly and continuously all within 2 minutes and the needle was slowly removed;(4) In the double injection group, 10 mL blood was injected at first, paused for 2 minutes, the rest 40 μL injected evenly within 2 minutes, and then the needle was withdrawn slowly and uninterruptedly. Neurologic findings were scored in accordance with Longa's five-point scale (0-4 scores, the higher the score, the severer the neurological dysfunction). The rats were killed to remove and sections were prepared, the morphological features of hematomas were grossly observed, the maximal diameter and size of hematomas in each slice were measured with the imaging analytical system, and the volume was calculated. Meanwhile, the conveniences of the techniques were compared. MAIN OUTCOME MEASURES: The morphological features and volume of hematomas, neurologic deficit score (NDS), and the convenience of the techniques were compared. RESULTS: All the 30 rats were involved in the analysis of results without deletion. (1) Results of the morphological observation of volume of hematoma: In the two-step injection group, hematomas located in the right caudate nucleus area regularly in circular or analogously circular shape in each slice. The formation rate of hematomas in the single injection group and double injection group were lower than those in the two-step injection group [60% (6/10), 80% (8/10), 100% (10/10), P〈 0.01, 0.05]. The volume of hematomas in the single injection group and double injection group were smaller than those in the two-step injection group [(28.5±14.8), (33.4±7.4), (41.6±3.9) mm3, P〈 0.01, 0.05]. (2) NDS results: The NDS scores in the single injection group and double injection group were smaller than that in the two-step injection group (0.90±0.83, 1.30±0.78, 1.90±0.57, P〈 0.05). (3)Comparison of the convenience of the techniques: The double injection method allowed generating reproducible hematomas in rats with shortcomings that it needed autologous arterial blood from femoral artery, and precision instruments such as microinfusion pump. The two-step injection injected fresh unclotting blood taken directly from the tail cut with microsyringe into the rat brain, and it has the advantages of easy operation, no influence on the activity of thrombase, shorter duration for model establishment, and higher rate of hematoma formation, which could generate ideal and economical models of ICH. The two-step injection induced hemotoma regularly in circular or analogously circular shape in each slice, but those induced by single and double injections were mostly in strip or fusiform shapes and extending along the needle tracks or into the ventricle or subarachnoid space. CONCLUSION : The autologous blood ICH model induced by the two-step injection method is a reproducible and reliable one in regular shape, which is better than those induced by double and single injections.
基金Supported by the Fundamental Research Funds for the Central Universities under Grant No 2018MS004
文摘We present a conceptual configuration of a high-temperature superconducting(HTS)magnet made from REBCO(Re=Rare Earth,B=Barium,C=Copper,O=Oxide)annular plates,called a Bitter-like HTS magnet,which can operate in persistent current mode without joint resistance and can be excited by a flux pump and without current leads and a persistent power supply.An REBCO annular magnet which can generate 1.5 T corresponding to the operating current density 80%of critical current density of the magnet at an operating temperature of65 K is conceptually designed.Then the thermal stability of the magnet is numerically simulated by Comsol software.Whein a piece of RBCO annular plate quenches,the maximum released energy is its stored energy because each REBCO annular plate in the Bitter-like magnet is in parallel.To calculate the stored energy in the REBCO annular plate,the inductance of every annular plate,including self-inductance and mutual inductance,is calculated.Compared with the minimum quench energy(MQE)and stored energy in one REBCO annular plate,the stored energy in one REBCO annular plate is always smaller than the MQE,and the REBCO annular plate will not be damaged even though the stored energy in the REBCO annular plate is fully released,which indicates that this 1.5 T Bitter-like magnet has the property of self-protection.
基金funded by Vietnam National Foundation for Science and Technology Development (NAFOSTED)under Grant No.105.08-2019.03.
文摘Flash floods are one of the most dangerous natural disasters,especially in hilly terrain,causing loss of life,property,and infrastructures and sudden disruption of traffic.These types of floods are mostly associated with landslides and erosion of roads within a short time.Most of Vietnamis hilly and mountainous;thus,the problem due to flash flood is severe and requires systematic studies to correctly identify flood susceptible areas for proper landuse planning and traffic management.In this study,three Machine Learning(ML)methods namely Deep Learning Neural Network(DL),Correlation-based FeatureWeighted Naive Bayes(CFWNB),and Adaboost(AB-CFWNB)were used for the development of flash flood susceptibility maps for hilly road section(115 km length)of National Highway(NH)-6 inHoa Binh province,Vietnam.In the proposedmodels,88 past flash flood events were used together with 14 flash floods affecting topographical and geo-environmental factors.The performance of themodels was evaluated using standard statisticalmeasures including Receiver Operating Characteristic(ROC)Curve,Area Under Curve(AUC)and Root Mean Square Error(RMSE).The results revealed that all the models performed well(AUC>0.80)in predicting flash flood susceptibility zones,but the performance of the DL model is the best(AUC:0.972,RMSE:0.352).Therefore,the DL model can be applied to develop an accurate flash flood susceptibility map of hilly terrain which can be used for proper planning and designing of the highways and other infrastructure facilities besides landuse management of the area.
文摘Objective To evaluate the sensitivity and specificity of body mass index (BMI), waist circumference (WC) and waist-to-hip ratio (WHR) measurements in diagnosing abdominal visceral obesity. Methods BMI, WC, and WHR were assessed in 690 Chinese adults (305 men and 385 women) and compared with magnetic resonance imaging (MRI) measurements of abdominal visceral adipose tissue (VA). Receiver operating characteristic (ROC) curves were generated and used to determine the threshold point for each anthropometric parameter. Results 1) MRI showed that 61.7% of overweight/obese individuals (BMI≥25 kg/m2) and 14.2% of normal weight (BMI<25 kg/m2) individuals had abdominal visceral obesity (VA≥100 cm2). 2) VA was positively correlated with each anthropometric variable, of which WC showed the highest correlation (r=0.73-0.77, P<0.001). 3) The best cut-off points for assessing abdominal visceral obesity were as followed: BMI of 26 kg/m2, WC of 90 cm, and WHR of 0.93, with WC being the most sensitive and specific factor. 4) Among subjects with BMI≥28 kg/m2 or WC≥95 cm, 95% of men and 90% of women appeared to have abdominal visceral obesity. Conclusion Measurements of BMI, WC, and WHR can be used in the prediction of abdominal visceral obesity, of which WC was the one with better accuracy.
基金supported by grants from the National Natural Science Foundation of China(81301275,81471736 and 81671760)the National Science and Technology Pillar Program during the Twelfth Five-Year Plan Period(2015BAI01B09)Heilongjiang Province Foundation for Returness(LC2013C38)
文摘BACKGROUND: The various combination of multiphase enhancement multislice spiral CT (MSCT) makes the diagno- sis of a small hepatocellular carcinoma (sHCC) on the back- ground of liver cirrhosis possible. This study was to explore whether the combination of MSCT enhancement scan and alpha-fetoprotein (AFP) level ficiency for sHCC. could increase the diagnostic ef- METHODS: This study included 35 sHCC patients and 52 cir- rhotic patients without image evidence of HCC as a control group. The diagnoses were made by three radiologists em- ploying a 5-point rating scale, with postoperative pathologic results as the gold standard. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the diag- nostic value of the three MSCT combination modes (arterial phase+portal-venous phase, arterial phase+delayed phase, arterial phase+portal-venous phase+delayed phase) and AFP levels for sHCC on the background of liver cirrhosis. RESULTS: The area under ROC curve (AUC), sensitivity, and specificity of the combination of arterial phase+portal- venous phase+delayed phase were 0.93, 93%, and 82%, respectively. The average AUC of the arterial phase+portal- venous phase+delayed phase combination was significantly greater than that of the arterial phase+portal-venous phase (AUC=0.84, P=0.01) and arterial phase+delayed phase (AUC=0.85, P=0.03). Arterial phase+portal-venous phase had a smaller AUC (0.84) than arterial phase+delayed phase (0.85), but the difference was insignificant (P=0.15). After combining MSCT enhancement scan with AFP, the AUC, sensitivity, and specificity were 0.95, 94%, and 83%, respectively, indicating a greatly increased diagnostic efficiency for sHCC. CONCLUSIONS: The combination of AFP and 3 phases MSCT enhancement scan could increase the diagnostic efficiency for sHCC on the background of liver cirrhosis. The application of ROC curve analysis has provided a new method and reference in HCC diagnosis.
基金Supported by Major Science and Technology Special Project of China Thirteenth Five-Year Plan,No.2018ZX10732401-003-015;Guangxi Key Laboratory for the Prevention and Control of Viral Hepatitis,No.GXCDCKL201901
文摘BACKGROUND Hepatitis B virus (HBV) infection is the primary cause of hepatitis with chronic HBV infection,which may develop into liver fibrosis,cirrhosis and hepatocellular carcinoma.Detection of early-stage fibrosis related to HBV infection is of great clinical significance to block the progression of liver lesion.Direct liver biopsy is regarded as the gold standard to detect and assess fibrosis;however,this method is invasive and prone to clinical sampling error.In order to address these issues,we attempted to find more convenient and effective serum markers for detecting HBV-induced early-stage liver fibrosis.AIM To investigate serum N-glycan profiling related to HBV-induced liver fibrosis and verify multiparameter diagnostic models related to serum N-glycan changes.METHODS N-glycan profiles from the sera of 432 HBV-infected patients with liver fibrosis were analyzed.Significant changed N-glycan levels (peaks)(P <0.05) in differentfibrosis stages were selected in the modeling group,and multiparameter diagnostic models were established based on changed N-glycan levels by logistic regression analysis.The receiver operating characteristic (ROC) curve analysis was performed to evaluate diagnostic efficacy of N-glycans models.These models were then compared with the aspartate aminotransferase to platelet ratio index (APRI),fibrosis index based on the four factors (FIB-4),glutamyltranspeptidase platelet albumin index (S index),GlycoCirrho-test,and GlycoFibro-test.Furthermore,we combined multiparameter diagnostic models with alanine aminotransferase (ALT) and platelet (PLT) tests and compared their diagnostic power.In addition,the diagnostic accuracy of N-glycan models was also verified in the validation group of patients.RESULTS Multiparameter diagnostic models constructed based on N-glycan peak 1,3,4and 8 could distinguish between different stages of liver fibrosis.The area under ROC curves (AUROCs) of Model A and Model B were 0.890 and 0.752,respectively differentiating fibrosis F0-F1 from F2-F4,and F0-F2 from F3-F4,and surpassing other serum panels.However,AUROC (0.747) in Model C used for the diagnosis of F4 from F0-F3 was lower than AUROC (0.795) in FIB-4.In combination with ALT and PLT,the multiparameter models showed better diagnostic power (AUROC=0.912,0.829,0.885,respectively) when compared with other models.In the validation group,the AUROCs of the three combined models (0.929,0.858,and 0.867,respectively) were still satisfactory.We also applied the combined models to distinguish adjacent fibrosis stages of 432patients (F0-F1/F2/F3/F4),and the AUROCs were 0.917,0.720 and 0.785.CONCLUSION Multiparameter models based on serum N-glycans are effective supplementary markers to distinguish between adjacent fibrosis stages of patients caused by HBV,especially in combination with ALT and PLT.
基金supported by grants from Dongzhimen Hospital Fund of Special Talent(2018RC01)Beijing University of Chinese Medicine Fund of Project(2019-JYB-XJSJJ-025)
文摘BACKGROUND:The study aimed to evaluate the predictive role of interleukin-6(IL-6)and chronic obstructive pulmonary disease(COPD)assessment test(CAT)score in mechanical ventilation(MV)in COPD patients at the acute exacerbation stage in the emergency department(ED).METHODS:For a one-year period,among adult patients in the ED who met the criteria of acute exacerbation of COPD,158 who received MV within 48 hours after admission were compared to 294 who didn't require MV within the same period after admission.IL-6 level and CAT score were compared between the two groups.The predicted value of IL-6 and CAT score was assessed by logistic regression analysis and a receiver operating characteristic(ROC)curve.RESULTS:The IL-6 and CAT scores in the 158 MV patients were much higher than those without.IL-6 and CAT scores were independent predictors of MV within 48 hours using logistic regression analysis(IL-6:odds ratio[OR]1.053,95%confidence interval[CI]1.039–1.067,P<0.001;CAT score:OR 1.122,95%CI 1.086–1.159,P<0.001).The combination of IL-6 and CAT scores(area under ROC curve[AUC]0.826,95%CI 0.786–0.866,P<0.001)improved the accuracy of predicting MV within 48 hours when compared with IL-6(AUC 0.752,95%CI 0.703–0.800,P<0.001)and CAT scores alone(AUC 0.739,95%CI 0.692–0.786,P<0.001).The sensitivity and specificity were 69.6%,74.1%,75.32%and 63.6%,respectively.CONCLUSION:The combined of IL-6 and CAT scores is useful for evaluating the risk of COPD patients at acute exacerbation in ED,and can provide a predictive value for MV or not within 48 hours.
文摘AIM: To study the expression of β-catenin in esophageal squamous cell carcinoma (ESCC) at stage T2-3N0M0 and its relation with the prognosis of ESCC patients. METHODS: Expression of β-catenin in 227 ESCC speci-mens was detected by immunohistochemistry (IHC). A reproducible semi-quantitative method which takes both staining percentage and intensity into account was applied in IHC scoring, and receiver operating char-acteristic curve analysis was used to select the cut-off score for high or low IHC reactivity. Then, correlation of β-catenin expression with clinicopathological features and prognosis of ESCC patients was determined. RESULTS: No significant correlation was observed between β-catenin expression and clinicopathological parameters in terms of gender, age, tumor size, tumor grade, tumor location, depth of invasion and pathologi-cal stage. The Kaplan-Meier survival curve showed that the up-regulated expression of β-catenin indicated a poorer post-operative survival rate of ESCC patients at stage T2-3N0M0 (P = 0.004), especially of those with T3 lesions (P = 0.014) or with stage ⅡB diseases (P = 0.007). Multivariate analysis also confirmed that β-catenin was an independent prognostic factor for the overall survival rate of ESCC patients at stage T2-3N0M0 (relative risk = 1.642, 95% CI: 1.159-2.327, P = 0.005). CONCLUSION: Elevated β-catenin expression level may be an adverse indicator for the prognosis of ESCC patients at stage T2-3N0M0, especially for those with T3 lesions or stage ⅡB diseases.
基金the Second People's Hospital of Anhui Province,Institutional Review Board(Approval No.2015-036).
文摘BACKGROUND Serum gastrin-17(G-17),pepsinogen I(PGI),and pepsinogen II(PGII)concentrations regulate gastric acid secretion,and hypersecretion of gastric acid increases the risks of peptic ulcer and upper gastrointestinal bleeding.These associations suggest that serum G-17,PGI,and(or)PGII may predict gastrointestinal bleeding risk among peptic ulcer patients.AIM To evaluate the efficacies of serum G-17,PGI,PGII,and PGI/PGII ratio(PGR)for predicting upper gastrointestinal bleeding among peptic ulcer patients.METHODS A total of 199 patients diagnosed with peptic ulcer confirmed by gastroscopy and positivity for Helicobacter pylori by the 14C-urea breath test were recruited,including 107 patients with simple peptic ulcer and 92 cases complicated by upper gastrointestinal bleeding.Serum PGI,PGII,G-17,and PGR were measured by immune methods and compared between bleeding and non-bleeding groups by univariate analysis.The specificity and sensitivity of PGs and G-17 for evaluating upper gastrointestinal bleeding risk were then assessed by constructing receiver operating characteristic(ROC)curves.RESULTS Serum G-17 was significantly higher among peptic ulcer patients with upper gastrointestinal bleeding compared to simple peptic ulcer patients(25.34±14.29 vs 8.84±8.03 pmol/L,t=9.822,P<0.01),whereas serum PGI,PGII,and PGR did not differ significantly between bleeding and non-bleeding groups(all P>0.05).The risk of bleeding was significantly higher among peptic ulcer patients with elevated serum G-17(>15 pmol/L)compared to patients with normal or low serum G-17(73.2%vs 27.4%,χ2=40.72,P<0.01).The area under the ROC curve for serum G-17 was 0.866±0.024,and a cut-off of 9.86 pmol/L yielded 90.2%sensitivity and 68.2%specificity for distinguishing peptic ulcer with and without upper gastrointestinal bleeding.CONCLUSION Serum G-17 is significantly upregulated in peptic ulcer patients and higher levels are predictive of upper gastrointestinal bleeding.Conversely,serum PGI,PGII,and PGR have no predictive value.Further prospective studies are warranted to examine if high G-17 can be used to assess risk of bleeding prior to onset.
文摘Landslide is considered as one of the most severe threats to human life and property in the hilly areas of the world.The number of landslides and the level of damage across the globe has been increasing over time.Therefore,landslide management is essential to maintain the natural and socio-economic dynamics of the hilly region.Rorachu river basin is one of the most landslide-prone areas of the Sikkim selected for the present study.The prime goal of the study is to prepare landslide susceptibility maps(LSMs)using computer-based advanced machine learning techniques and compare the performance of the models.To properly understand the existing spatial relation with the landslide,twenty factors,including triggering and causative factors,were selected.A deep learning algorithm viz.convolutional neural network model(CNN)and three popular machine learning techniques,i.e.,random forest model(RF),artificial neural network model(ANN),and bagging model,were employed to prepare the LSMs.Two separate datasets including training and validation were designed by randomly taken landslide and nonlandslide points.A ratio of 70:30 was considered for the selection of both training and validation points.Multicollinearity was assessed by tolerance and variance inflation factor,and the role of individual conditioning factors was estimated using information gain ratio.The result reveals that there is no severe multicollinearity among the landslide conditioning factors,and the triggering factor rainfall appeared as the leading cause of the landslide.Based on the final prediction values of each model,LSM was constructed and successfully portioned into five distinct classes,like very low,low,moderate,high,and very high susceptibility.The susceptibility class-wise distribution of landslides shows that more than 90%of the landslide area falls under higher landslide susceptibility grades.The precision of models was examined using the area under the curve(AUC)of the receiver operating characteristics(ROC)curve and statistical methods like root mean square error(RMSE)and mean absolute error(MAE).In both datasets(training and validation),the CNN model achieved the maximum AUC value of 0.903 and 0.939,respectively.The lowest value of RMSE and MAE also reveals the better performance of the CNN model.So,it can be concluded that all the models have performed well,but the CNN model has outperformed the other models in terms of precision.
基金Supported by the Ministerio de Ciencia e Innovación(SAF:2010/21805,partially)CIBERehd(Instituto de Salud CarlosⅢ,Madrid)+1 种基金Fundación Mutua Madrile■a(to Moreno-Otero R)a grant from Asociación Espa■ola Contra el Cáncer(AIO 2010,AECC,to Sanz-Cameno P)
文摘AIM To evaluate the efficacy of peripheral blood concentrations of angiopoietins(Ang) as cirrhosis biomarkers of chronic hepatitis C(CHC).METHODS Ang1 and Ang2 serum levels were measured by enzyme-linked immunosorbent assays(ELISA) in samples from 179 cirrhotic and non-cirrhotic CHC patients, classified according to the METAVIR system.Groups were compared by non-parametric MannWhitney U test. Subsequently, the association of peripheral concentrations of angiopoietins with the stage of fibrosis was analyzed using Spearman correlation test. Finally, the accuracy, sensitivity and specificity of circulating angiopoietins for cirrhosis diagnosis were determined by the study of the respective area under the curve of receiver operator characteristics(AUC-ROC).RESULTS Peripheral blood concentrations of Ang1 and Ang2 in CHC patients were significantly related to fibrosis. While Ang1 was decreased in cirrhotic subjects compared to non-cirrhotic(P < 0.0001), Ang2 was significantly increased as CHC progressed to the end stage of liver disease(P < 0.0001). Consequently, Ang2/Ang1 ratio was notably amplified and significantly correlated with fibrosis(P < 0.0001). Interestingly, the individual performance of each angiopoietin for the diagnosis of cirrhosis reached notable AUC-ROC values(above 0.7, both), but the Ang2/Ang1 ratio was much better(AUC-ROC = 0.810) and displayed outstanding values of sensitivity(71%), specificity(84%) and accuracy(82.1%) at the optimal cut-off(10.33). Furthermore, Ang2/Ang1 ratio improved the performance of many other previously described biomarkers or scores of liver cirrhosis in CHC.CONCLUSION Ang2/Ang1 ratio might constitute a useful tool for monitoring the progression of chronic liver disease towards cirrhosis and play an important role as therapeutic target.
文摘Mixed traffic flow composed of autos and non-autos widely exists in developing countries and areas. To investigate the operational characteristics of the mixed traffic flow consisting of vehicles in different types (large vehicles, cars, and bicycles), we develop a cellular automaton model to repli- cate the travel behaviors on a bi-directional road segment with respect to the physical and mechanic features of different vehicle types. By implementing the essential parameters calibrated through the field data collection, a numerical study is carried out considering the variation in volume, density, and velocity with different compositions of mixed traffic flows. The primary findings include: the average ve- locity of traffic flow and total volume decrease 60% and 30% after incorporating 10% bicycles, respectively; the phenomenon of double-summit in terms bicycle is beyond 60 % ; the maximal total volume higher than 10 %. of the total volume appears when the proportion of starts to recover when the proportion of bicycle is
基金by National Science and Technology Major Project,No.2017ZX10302201,No.2017ZX09304004 and No.2014ZX10002002National Program on Key Basic Research Project(973 Program),No.2015CB554304.
文摘BACKGROUND Quantitative hepatitis B core-related antigen(qHBcrAg)has a better correlation with intrahepatic hepatitis B virus(HBV)covalently closed circular DNA(cccDNA)than HBV DNA or hepatitis B e antigen(HBeAg),but data are still lacking for its clinical application.AIM The aim was to investigate serum qHBcrAg levels in patients with chronic hepatitis B and assess the correlation of serum qHBcrAg with pregenomic RNA(pgRNA),cccDNA,and HBeAg seroconversion.METHODS This study was a secondary analysis of patients who underwent percutaneous liver biopsy between July 2014 and June 2019 in two multicenter randomized controlled clinical trials of peginterferon vs nucleos(t)ide analog(NUC)-based therapy(NCT03509688 and NCT03546530).Serum qHBcrAg,pgRNA,HBV DNA,hepatitis B core antigen,HBeAg,liver cccDNA,and HBV DNA were measured.The correlations of serum qHBcrAg with other biomarkers were analyzed.RESULTS A total of 139 patients were included.The mean qHBcrAg levels were 5.32±1.18 log10 U/mL at baseline and decreased during treatment(all P<0.0001).Serum qHBcrAg levels were positively correlated with pgRNA(r=0.597,P<0.0001)and cccDNA(r=0.527,P<0.0001)levels.The correlation of serum qHBcrAg level and intrahepatic HBV DNA levels at baseline was weak but significant(r=0.399,P<0.0001).HBcrAg predicted HBeAg seroconversion,with areas under the receiver operating characteristics curve of 0.788 at 24 wk and 0.825 at 48 wk.Log HBcrAg at wk 24 and 48 was independently associated with HBeAg seroconversion[odds ratio(OR)=2.402,95%confidence interval(CI):1.314-4.391,P=0.004;OR=3.587,95%CI:1.315-9.784,P=0.013].CONCLUSION Serum HBcrAg levels were correlated with HBV virological markers and could be used to predict HBeAg seroconversion.
文摘BACKGROUND Autism is the most common clinical developmental disorder in children.The childhood autism rating scale(CARS)and autistic autism behavior checklist(ABC)are the most commonly used assessment scales for diagnosing autism.However,the diagnostic validations and the corresponding cutoffs for CARS and ABC in individuals with suspected autism spectrum disorder(ASD)remain unclear.Furthermore,for suspected ASD in China,it remains unclear whether CARS is a better diagnostic tool than ABC.Also unclear is whether the current cutoff points for ABC and CARS are suitable for the accurate diagnosis of ASD.AIM To investigate the diagnostic validity of CARS and ABC based on a large Chinese sample.METHODS A total of 591 outpatient children from the ASD Unit at Beijing Children’s Hospital between June and November 2019 were identified.First,the Clancy autism behavior scale(CABS)was used to screen out suspected autism from these children.Then,each suspected ASD was evaluated by CARS and ABC.Receiver operating characteristic(ROC)curve analysis was used to compare diagnostic validations.We also calculated the area under the curve(AUC)for both CARS and ABC.RESULTS We found that the Cronbach alpha coefficients of CARS and ABC were 0.772 and 0.426,respectively.Therefore,the reliability of the CARS was higher than that of the ABC.In addition,we found that the correlation between CARS and CABS was 0.732.Next,we performed ROC curve analysis for CARS and ABC,which yielded AUC values of 0.846 and 0.768,respectively.The cutoff value,which is associated with the maximum Youden index,is usually applied as a decision threshold.We found that the cutoff values of CARS and ABC were 34 and 67,respectively.CONCLUSION This result indicated that CARS is superior to ABC in the Chinese population with suspected ASD.
基金Supported by Quanzhou Science and Technology Bureau,No.2018N053S.
文摘BACKGROUND Silicosis is a type of chronic pulmonary fibrosis caused by long-term inhalation of silica dust particles.There has been no ideal biomarker for the diagnosis and differential diagnosis of silicosis until now.Studies have found that elevated neuron-specific enolase(NSE)concentration in the serum of silicosis patients is helpful for diagnosis and severity assessment of the disease.However,the number of cases in these studies was not enough to arouse attention.AIM To investigate the clinical significance of serum NSE in the diagnosis and staging of silicosis.METHODS From January 2017 to June 2019,326 cases of silicosis confirmed in Quanzhou First Hospital Affiliated to Fujian Medical University were included in the silicosis group.A total of 328 healthy individuals or medical patients without silicosis were included in the control group.Serum NSE concentrations of all subjects were determined by electrochemical luminescence.RESULTS There were no significant differences in sex,age,smoking index and complications between the silicosis and control groups.The mean serum NSE concentration was 26.57±20.95 ng/mL in the silicosis group and 12.42±2.68 ng/mL in the control group.The difference between the two groups was significant(U=15187,P=0.000).Among the 326 patients with silicosis,103 had stage I silicosis,and the mean serum NSE concentration was 15.55±6.23 ng/mL.The mean serum NSE concentration was 21.85±12.05 ng/mL in 70 patients with stage II silicosis.The mean serum NSE concentration was 36.14±25.72 ng/mL in 153 patients with stage III silicosis.Kruskal-Wallis H test suggested that the difference in serum NSE concentration in silicosis patients in the three groups was significant(H=130.196,P=0.000).Receiver operating characteristic curve analysis indicated that the area under the curve was 0.858(95%confidence interval:0.828-0.888;P=0.000).When the NSE concentration was 15.82 ng/mL,the Jorden index was the largest,the sensitivity was 72%,and the specificity was 90%.CONCLUSION Serum NSE concentration may be a promising biomarker for the diagnosis and assessment of severity of silicosis.
基金by the Zhejiang Province Traditional Chinese Medicine Science and Technology Plan-Zhejiang Province Traditional Chinese Medicine Project for Traditional Chinese Medicine Scientific Research(2020)(Class B),No.2020ZB117。
文摘BACKGROUND For lung adenocarcinoma with epidermal growth factor receptor(EGFR)gene mutation,small molecule tyrosine kinase inhibitors are more effective.Some patients could not obtain enough histological specimens for EGFR gene mutation detection.Specific imaging features can predict EGFR mutation status to a certain extent.AIM To assess the associations of EGFR mutations with high-resolution computerized tomography(HRCT)features in ground-glass nodular lung adenocarcinoma.METHODS This study retrospectively assessed patients with ground-glass nodular lung adenocarcinoma diagnosed between January 2011 and March 2017.EGFR gene mutations in exons 18-21 were detected.The patients were classified into mutant EGFR and wild-type groups,and general data and HRCT image characteristics were assessed.RESULTS Among 98 patients,31(31.6%)and 67(68.4%)had mutated and wild-type EGFR in exons 18-21,respectively.Gender,age,smoking history,location of lesions,morphology,edges,borders,pleural indentations,and associations of nodules with bronchus and blood vessels were comparable in both groups(all P>0.05).Patients with mutant EGFR had larger nodules than those with the wild-type(17.19±6.79 and 14.37±6.30 mm,respectively;P=0.047).Meanwhile,the vacuole/honeycomb sign was more frequent in the mutant EGFR group(P=0.011).The logistic regression prediction model included the combination of nodule size and vacuole/honeycomb sign(OR=1.120,95%CI:1.023-1.227,P=0.014)revealed a sensitivity of 83.9%,a specificity of 52.2%and an AUC of 0.698(95%CI:0.589-0.806;P=0.002).CONCLUSION Nodule size and vacuole/honeycomb features could independently predict EGFR mutation status in ground-glass nodular lung adenocarcinoma.