Predicting potential invasion risks of Leucaena leucocephala(Lam.)de Wit in the arid area of Saudi Arabia

The presence of invasive plant species poses a substantial ecological impact,thus comprehensive evaluation of their potential range and risk under the influence of climate change is necessary.This study uses maximum entropy(MaxEnt)modeling to forecast the likelihood of Leucaena leucocephala(Lam.)de Wit invasion in Saudi Arabia under present and future climate change scenarios.Utilizing the MaxEnt modeling,we integrated climatic and soil data to predict habitat suitability for the invasive species.We conducted a detailed analysis of the distribution patterns of the species,using climate variables and ecological factors.We focused on the important influence of temperature seasonality,temperature annual range,and precipitation seasonality.The distribution modeling used robust measures of area under the curve(AUC)and receiver-operator characteristic(ROC)curves,to map the invasion extent,which has a high level of accuracy in identifying appropriate habitats.The complex interaction that influenced the invasion of L.leucocephala was highlighted by the environmental parameters using Jackknife test.Presently,the actual geographic area where L.leucocephala was found in Saudi Arabia was considerably smaller than the theoretical maximum range,suggesting that it had the capacity to expand further.The MaxEnt model exhibited excellent prediction accuracy and produced reliable results based on the data from the ROC curve.Precipitation and temperature were the primary factors influencing the potential distribution of L.leucocephala.Currently,an estimated area of 216,342 km^(2)in Saudi Arabia was at a high probability of invasion by L.leucocephala.We investigated the potential for increased invasion hazards in the future due to climate change scenarios(Shared Socioeconomic Pathways(SSPs)245 and 585).The analysis of key climatic variables,including temperature seasonality and annual range,along with soil properties such as clay composition and nitrogen content,unveiled their substantial influence on the distribution dynamic of L.leucocephala.Our findings indicated a significant expansion of high risk zones.High-risk zones for L.leucocephala invasion in the current climate conditions had notable expansions projected under future climate scenarios,particularly evident in southern Makkah,Al Bahah,Madina,and Asir areas.The results,backed by thorough spatial studies,emphasize the need to reduce the possible ecological impacts of climate change on the spread of L.leucocephala.Moreover,the study provides valuable strategic insights for the management of invasion,highlighting the intricate relationship between climate change,habitat appropriateness,and the risks associated with invasive species.Proactive techniques are suggested to avoid and manage the spread of L.leucocephala,considering its high potential for future spread.This study enhances the overall comprehension of the dynamics of invasive species by combining modeling techniques with ecological knowledge.It also provides valuable information for decision-making to implement efficient conservation and management strategies in response to changing environmental conditions.

Determination of Carboplatin Dose by Area Under the Curve in Combination Chemotherapy for Senile Non-small Cell Lung Cancer

To preliminarily determine the appropriate dosage of carboplatin （CBP） at AUC of 5 mg-M1^-1·min^-1 in the combination chemotherapy for Chinese senile patients with non-small cell lung cancer （NSCLC）. Thirty-five Chinese senile patients with NSCLC in advanced stage （Ⅲ/Ⅳ） were given 96 cycles of combination chemotherapy. Chemotherapy schedules included Taxol＋CBP, Gemzar＋CBP and NVB＋CBE The dose of CBP was at 5 mg.mL^-1·min^-1 of area under the concentration-time curve （AUC）. Side effects and quality of life were observed before and after the chemotherapy. Myelosuppression was severe and commonly observed. Grade 3/4 of granulocytopenia was found in 47.9% （46/96） of the patients and grade 3/4 of thrombocytopenia was noted in 28.1% （27/96） of the subjects. However, other side effects were slight. The mean score of quality of life （QOL）, according to the criteria of QOL for Chinese cancer patients had reduced 6.8. At 5 mg.mL^-1·min^-1 by AUC, the hematological toxicity of CBP was severe and it had some negative effects on the QOL. The administration of CBP at 5 mg.mL^-1·min^-1 by AUC may be too high for Chinese senile patients with non-small cell lung cancer.

Area under the curve of methotrexate and creatinine clearance are outcome - determining factors in primary CNS lymphomas

Although high-dose methotrexate(HD-MTX)is the most effective drug against primary CNS lymphomas(PCNSL),outcome-de-termining variables related to its administration schedule have not been defined.The impact on toxicity and outcome of the area under thecurve(AUC(MTX)),dose intensity(DI(MTX))and infusion rate(IR(MTX))of MTX and plsamatic creatinine clearance(CL(crea))was investigated in a retrospective series of 45 PCNSL patients treated with three different HD-MTX-basedcombinations.Anticon-vulsants were administered in 31 pts(69%).Age>60 years,anticonvulsant therapy,slow IR(MTX)(

Gut microbiota predicts the diagnosis of ulcerative colitis in Saudi children

BACKGROUND Ulcerative colitis(UC)is an immune-mediated chronic inflammatory condition with a worldwide distribution.Although the etiology of this disease is still unknown,the understanding of the role of the microbiota is becoming increasingly strong.AIM To investigate the predictive power of the gut microbiota for the diagnosis of UC in a cohort of newly diagnosed treatment-naïve Saudi children with UC.METHODS The study population included 20 children with a confirmed diagnosis of UC and 20 healthy controls.Microbial DNA was extracted and sequenced,and shotgun metagenomic analysis was performed for bacteria and bacteriophages.Biostatistics and bioinformatics demonstrated significant dysbiosis in the form of reduced alpha diversity,beta diversity,and significant difference of abundance of taxa between children with UC and control groups.The receiver operating characteristic curve,a probability curve,was used to determine the difference between the UC and control groups.The area under the curve(AUC)represents the degree of separability between the UC group and the control group.The AUC was calculated for all identified bacterial species and for bacterial species identified by the random forest classification algorithm as important potential biomarkers of UC.A similar method of AUC calculation for all bacteriophages and important species was used.RESULTS The median age and range were 14(0.5-21)and 12.9(6.8-16.3)years for children with UC and controls,respectively,and 40%and 35%were male for children with UC and controls,respectively.The AUC for all identified bacterial species was 89.5%.However,when using the bacterial species identified as important by random forest classification algorithm analysis, the accuracy increased to 97.6%. Similarly, the AUC for all theidentified bacteriophages was 87.4%, but this value increased to 94.5% when the important bacteriophagebiomarkers were used.CONCLUSIONThe very high to excellent AUCs of fecal bacterial and viral species suggest the potential use of noninvasivemicrobiota-based tests for the diagnosis of unusual cases of UC in children. In addition, the identification ofimportant bacteria and bacteriophages whose abundance is reduced in children with UC suggests the potential ofpreventive and adjuvant microbial therapy for UC.

Relationship between the specific surface area of rust and the electrochemical behavior of rusted steel in a wet–dry acid corrosion environment

The relationship between the specific surface area（SSA） of rust and the electrochemical behavior of rusted steel under wet-dry acid corrosion conditions was investigated. The results showed that the corrosion current density first increased and then decreased with increasing SSA of the rust during the corrosion process. The structure of the rust changed from single-layer to double-layer, and the γ-FeOOH content decreased in the inner layer of the rust with increasing corrosion time; by contrast, the γ-FeOOH content in the outer layer was constant. When the SSA of the rust was lower than the critical SSA corresponding to the relative humidity during the drying period, condensed water in the micropores of the rust could evaporate, which prompted the diffusion of O_2 into the rust and the following formation process of γ-FeOOH, leading to an increase of corrosion current density with increasing corrosion time. However, when the SSA of the rust reached or exceeded the critical SSA, condensate water in the micro-pores of the inner layer of the rust could not evaporate which inhibited the diffusion of O_2 and decreased the γ-FeOOH content in the inner rust, leading to a decrease of corrosion current density with increasing corrosion time.

Smoothed Empirical Likelihood Inference for ROC Curves with Missing Data

The receiver operating characteristic (ROC) curve has been widely used in scientific research fields. After using the random hot deck imputation, we propose the smoothed empirical likelihood ratio statistic for the ROC curve with missing data. Its asymptotic distribution is a scaled chi-square distribution and empirical likelihood confidence intervals for ROC curves are constructed. The simulation study shows that the proposed interval estimates perform well based on the coverage probability for different sample sizes and response rates.

SOME REMARKS ABOUT THE AREA-PRESERVING CONVEX CURVE FLOW IN THE PLANE

Using Picard's theorem and the Leray-Schauder fixed point theorem to reinvestigate the area-preserving convex curve flow in the plane which is considered as a coupled system and thus different from the setting handled by Gage.

受试者工作特征曲线(ROC曲线)的应用分析

目的:通过分析《中国计划生育学杂志》中受试者工作特征曲线(简称ROC曲线)的应用情况,为规范应用ROC曲线提供建议。方法:在中国知网检索2018年1月1日-2022年12月31日《中国计划生育学杂志》发表的与ROC曲线相关的文献,根据是否使用多指标联合预测结局,将文献分为单独组和联合组,分析文献的发表数量变化趋势、研究领域、应用条件、统计软件和模型。结果:共获得323篇文献。根据纳入排除标准,排除11篇文献,最终纳入312篇,其中单独组125篇、联合组187篇。最常用的统计软件为SPSS,数量达303篇,占97.1%,286篇文章仅提及使用ROC分析诊断价值,而未指出具体的拟合方法。2018-2022年的文章发表数量呈逐年上升的趋势,所纳入学科领域文献数量的排名前3位的依次是围产医学(187篇,59.9%)、妇科肿瘤学(45篇,14.4%)和普通妇科学(40篇,12.8%)。纳入文献样本量M(P25,P75)为180.5(127,242),其中样本量<100例的文章29篇,占9.3%。整体的AUC值M(P25,P75)为0.812(0.747,0.881),68.3%的AUC值位于0.7~0.9,<0.5的AUC值共7个,占0.6%。在≥2个指标的诊断试验研究中,149篇文章中未进行AUC值统计学差异性检验,仅报告指标间诊断价值的高低;29篇文章仅报告统计学比较的P值,未报告具体使用的统计学比较方法。结论:在ROC曲线的应用中,需选择合适的模型,并建议在文章的方法部分详细报告所用的ROC模型和统计软件,若存在多个指标的比较,需进行统计学检验,并报告相应的Z值和P值。

Secure Authentication of WLAN Based on Elliptic Curve Cryptosystem

The security of wireless local area network （WI.AN） becomes a bottleneck for its further applications. At present, many standard organizations and manufacturers of WLAN try to solve this problem. However, owing to the serious secure leak in IEEES02.11 standards, it is impossible to utterly solve the problem by simply adding some remedies. Based on the analysis on the security mechanism of WLAN and the latest techniques of WI.AN security, a solution to WLAN security was presented. The solution makes preparation for the further combination of WLAN and Internet.

ROC analysis of CT hemodynamic in the diagnosis of breast cancer

Objective:The aim of this study was evaluate the diagnostic value of computed tomography(CT) perfusion in breast cancer by the method of receiver operator characteristic curve(ROC) analysis.Methods:Eighty-one cases with breast masses found by health examination or mammography were scanned by multi-slice spiral CT(MSCT) perfusion and hemodynamic parameters of blood flow(BF), mean transit time(MTT) and blood volume(BV) were calculated by deconvolution arithmetic.According to the pathologic results, two groups, benign and malignant were classified and statistical analysis were performed between them.The ROC characteristics of BF, MTT, BV were compared for each and the diagnostic value of the hemodynamic parameters were confirmed.Results:In the malignant group, BF was(0.735 ± 0.440) mL/min/mL, MTT was(22.771 ± 7.647) s and BV was 0.234 ± 0.082.In the benign group, BF was(0.466 ± 0.527) mL/min/mL, MTT was(26.712 ± 12.934) s and BV was 0.179 ± 0.117.There was a significant difference for BF and BV between the benign and malignant groups.When the hemodynamic parameters were used to discriminate the breast lesions, the area under the ROC curve(AUCROC) of BF was 0.832 ± 0.086, the maximum, while AUCROC of BV was 0.695 ± 0.092.There was no significant statistical difference between BF and BV.AUCROC of MTT was 0.473 ± 0.102, which was minimal.Since the threshold of BF was 0.381 mL/min/mL, the sensitivity was 82.3%, the specificity was 73.2%, the positive likelihood ratio(LR) was 3.071 and the negative LR was 0.242.The threshold of BV was 0.190 with sensitivity 73.3%, specificity 56.5%, positive likelihood ratio 1.685 and negative LR 0.473.Conclusion:BF and BV among CT hemodynamic parameters have certain diagnostic value in breast cancer, but BF or BV can not yet be single index to confirm or deny the diagnosis.

Analysis of Storm Pattern for Design Urban Drainage System in the Monsoon Areas of Vietnam

In Vietnam,rainfall data usually received using daily rainfall at all hydrology stations with higher time resolution are scarce.However,its analyses to achieve IDF(Intensity-Duration-Frequency)curves are often required at a finer scale such as hourly.Therefore,it needs to develop and apply methods to derive the IDF characteristics of short-duration events from daily rainfall statistics in Vietnam.In recent years,the need for new insights into the rainfall process leading to new approaches to model the distribution of rainfall intensities in time and space was recognized.This research aims to establish IDF curves for monsoon climate area in Vietnam based on scaling method.Scaling properties of extreme rainfall are examined in the Red River Delta of Vietnam in order to establish scaling behavior of statistical moments over different durations.Such scaling or scale-invariant models enable us to scale data from one temporal resolution to another,and thus,help to overcome the lack of the extreme rainfall data of sub-daily durations.The disaggregation or downscaling techniques are used to obtain sub-daily rainfall data from daily rainfall data for the derivation of scaled IDF curves.Research results show that most of rainfall amount(approximately 70%)received from rains occurring between 6:0 pm to 6:0 am of the day after that,the daytime usually less rainfall occurrence with only 30%.The peak rainfall is usually occurred during 0:0 am to 4:0 am having approximately 42.98%of rainfall amount over a day.The peak rainfall likely happen earlier in the recent year(36%rainfall amount over a day occurrence from 6:00 pm to 10:00 pm in 2008).The analysis also illustrated that approximately 40%of rainfall events have duration less than 60 minutes.In contrast,only approximately 9%of rainfall events have duration more than 6 hours but total rainfall depths of these events is approximately.

Evaluation of the diagnostic value of tumor markers with ROC and logistic regression in gastrocolic tumors

Objective: The aim of the study was to evaluate the clinical significance of multiple tumor markers (CEA, AFP, CA72-4 and CA19-9) in patients with gastrocolic tumors by receiver operating characteristic (ROC) curve and stepwise logistic regression (LR) analysis. Methods: The serum concentrations of CEA, AFP, CA72-4 and CA19-9 were measured with electrochemiluminescence immunoassay in 126 patients with gastrocolic tumors, 137 patients with benign gastrocolic disorders and 109 healthy controls. The area under the ROC curve (AUC) of CEA, AFP, CA72-4 and CA19-9 and stepwise LR results were compared by sensitivity, specificity, Youden's index and positive likelihood ratio/negative likelihood ratio. Results: The levels of four tested tumor markers in patients with gastrocolic tumors were significantly higher than those in benign gastrocolic group and normal controls. In the benign gastrocolic group, the AUC from stepwise logistic regression was larger than the AUC of four tumor markers respectively. Sensitivity, Youden's index and positive likelihood ratio/negative likelihood ratio were the highest in the combination assay of CA72-4, CEA, and CA19-9, as compared with one of the tumor markers alone. Conclusion: The use of ROC established by LR analysis model improved the diagnostic accuracy of gastrocolic tumors. For the screening of gastrocolic tumors, the AUC value of the combination probability index (sensitivity and specificity) was significantly higher than the values of the different tumour markers.

上海市远郊60岁及以上人群代谢综合征趋势分析及ROC曲线预测

目的:分析上海市远郊60岁及以上人群代谢综合征患病情况及变化趋势,比较血糖、身体质量指数对代谢综合征的评价作用,为相关部门制定代谢综合征防控措施提供参考依据。方法:2022—2023年,选取在上海市金山区高新区社区参与健康体检的19576名老年居民进行问卷调查、身体测量、生物样本采集。结果:参与体检的老年居民中,70~74岁年龄段人群代谢综合征患病率最高(24.8%),≥80岁年龄段人群代谢综合征患病率最低(17.8%);在代谢综合征组分数量方面,65~69岁年龄段人群包含1~4项的组分数量占比均为最高;男性空腹血糖、身体质量指数切点分别为6.05 mmol/L、25.0 kg/m2,ROC曲线下面积分别为0.720和0.824;女性葡萄糖、身体质量指数切点分别为5.92 mmol/L、25.0 kg/m2,ROC曲线下面积分别为0.714和0.798。结论:身体质量指数、空腹血糖是预测社区老年居民代谢综合征的重要变量,相关部门应重视身体质量指数、空腹血糖评估对社区居民代谢综合征的预测价值。

基于Logistic回归模型及ROC曲线的糖尿病足溃疡复发的危险因素分析

目的基于Logistic回归模型及ROC曲线的糖尿病足溃疡(DFU)复发的危险因素分析。方法回顾性选取2018年9月—2019年9月本院收治的92例初发2型糖尿病(T2DM)足溃疡患者,根据3年内足溃疡复发情况分为非复发组51例与复发组41例,行DFU患者足溃疡复发的单因素分析,多因素Logistic模型研究DFU患者足溃疡复发的危险因素,Spearman检验分析各指标与DFU患者足溃疡复发的相关性,受试者工作特征曲线(ROC)评价模型诊断效能。结果92例DFU患者随访3年,复发41例,复发率为44.57%。单因素分析显示,两组体质量指数(BMI)、性别、心脑血管疾病病史占比、高血压病史占比、住院时间、发病至就诊时间、ALB、TBIL、Scr、HbA1c、TG、HDL、TC、LDL差异无统计学意义(P>0.05);与非复发组比较,复发组年龄、T2DM病程、糖尿病周围神经病变(DPN)占比、下肢外周动脉病变(PAD)占比、吸烟史占比、创面位于胼胝占比明显升高,TBIL水平明显降低(均P<0.05)。多因素分析显示,年龄增大、T2DM病程长、合并DPN、合并PAD、有吸烟史、创面位于胼胝及血清TBIL水平降低为DFU患者足溃疡复发的危险因素(P<0.05)。Spearman检验提示,DFU患者足溃疡复发与年龄、T2DM病程、DPN、PAD、吸烟史、创面位于胼胝呈正相关,TBIL水平明显降低呈负相关(均P<0.05)。以unite(七变量综合)、年龄、T2DM病程、TBIL、DPN、PAD、吸烟、创面位于胼胝为检验变量绘制ROC曲线,结果显示,unite的AUC值为0.834,分别大于年龄(0.632)、T2DM病程(0.619)、TBIL(0.645)、DPN(0.684)、PAD(0.662)、吸烟(0.640)、创面位于胼胝(0.677),提示7项指标联合应用于评估DFU患者足溃疡复发的效能明显优于单一指标(P<0.05)。结论年龄增大、T2DM病程长、合并DPN、合并PAD、有吸烟史、创面位于胼胝、血清TBIL水平降低为DFU患者足溃疡复发的危险因素,如发现上述情况应高度警惕DFU患者足溃疡复发风险,并尽早干预。

ROC Analysis in Radiotherapy:A TCP Model-Based Test

Several mathematical models have been proposed to describe the dynamics of irradiated cancer cells and to evaluate the tumour control probability (TCP). In this article, we propose a TCP model-based statistical test for predicting the outcome of a radiation treatment. We determine the foresight capability of prostate tumour erradication (cure) from Monte Carlo simulations of the Dawson-Hillen TCP model. We construct the receiver operating characteristic (ROC) curves of the test from the probability distributions of the fraction of remaining tumour cells for simulated experiments that evolve either to cure or non-cure. Simulations show that a similar procedure may be applicable to clinical data. Results suggest that the evaluation of tumour sizes after the treatment has started may be used for short-term prognosis.

Combined detection of serum tumor markers for differential diagnosis of solid lesions located at the pancreatic head

BACKGROUND: The differential diagnosis of solid lesions located at the pancreatic head is very important for choosing therapies and setting up surgical tactics. This study was designed to evaluate the clinical significance of combined measurement of multiple serum tumor markers and the application of the receiver-operating characteristic (ROC) curves in the differential diagnosis of solid lesions located at the pancreatic head. METHODS: The serum levels of CA19-9, CA242, CA50 and carcinoembryonic antigen (CEA) in 112 patients with carcinoma of the pancreatic head and 38 patients with focal chronic pancreatitis in the pancreatic head were measured with ELISA. The sensitivity, specificity, positive likelihood ratio (PLR) and negative likelihood ratio (NLR) of the four serum tumor markers were calculated. The ROC curves for the four serum tumor markers were constructed and the area under the curve (AUC) was calculated. RESULTS: The AUCs of CA19-9, CA242, CA50 and CEA were 0.805, 0.749, 0.738 and 0.705; the PLRs were 1.91, 3.43, 5.09 and 5.46; and the NLRs were 0.41, 0.56, 0.59 and 0.71, respectively. Combined measurements increased the diagnostic specificity, and parallel combined testing increased the diagnostic sensitivity. CONCLUSIONS: Combined measurement of serum tumor markers CA19-9, CA242, CA50 and CEA is valuable in differential diagnosis of solid lesions located at the pancreatic head, and CA19-9 has the best diagnostic ability. Combined measurements can increase the specificity of diagnosis. Evaluation with the ROC curve is better than the sensitivity or specificity alone and the results are more integrated and objective.

Study on the value of serum miR-106b for the early diagnosis of hepatocellular carcinoma

AIM To analyze the incidence of hepatocellular carcinoma (HCC) in a population that underwent health checkups and had high serum miR-106b levels. METHODS A total of 335 subjects who underwent checkups in the Digestive and Liver Disease Department of our hospital were randomly selected. RT-PCR was used to detect the level of miR-106b in serum samples. Laboratory and imaging examinations were carried out to confirm the HCC diagnosis in patients who had a > 2-fold change in miR-106b levels. Ultrasound-guided biopsy was also used for HCC diagnosis when necessary. On this basis, the clinical data of these subjects, including history of hepatitis virus infection, obesity, long-term history of alcohol use and stage of HCC, were collected. Then, the impact of these factors on the level of miR1-06b in serum was analyzed. Furthermore, receiver operating characteristic (ROC) curve was drawn to evaluate the diagnostic efficacy of miR-106b for HCC. RESULTS A total of 35 subjects had abnormal serum miR-106b levels, of which 20 subjects were diagnosed with HCC. t-test revealed that the difference in serum miR-106b level in terms of sex, age, history of hepatitis virus infection, obesity and long-term history of alcohol use was not statistically significant. However, serum miR-106b levels in patients with advanced HCC (stage. /.) was higher than in patients with early HCC (stage./.), and the difference was statistically significant (P = 0.000). Moreover, the ROC curve revealed that the area under the curve value for miR-106b was 0.885, which shows that serum miR-106b level has a certain clinical value for HCC diagnosis. CONCLUSION The random sampling survey shows that serum miR-106b level is a valuable diagnostic marker for HCC. However, the diagnostic threshold value needs to be further researched.

Percent free prostate-specific antigen for prostate cancer diagnosis in Chinese men with a PSA of 4.0-10.0 ng/mL:Results from the Chinese Prostate Cancer Consortium

Objective:To test the diagnostic performance of percent free prostate-specific antigen(%fPSA)in predicting any prostate cancer(PCa)and high-grade prostate cancer(HGPCa)in a retrospective multi-center biopsy cohort with a PSA level of 4.0e10.0 ng/mL in China.Methods:Consecutive patients with a PSA of 4.0-10.0 ng/mL who underwent transrectal ultrasound-guided biopsy were enrolled at 16 Chinese medical centers from January 1st,2010 to December 31st,2013.Total and free serum PSA determinations were performed using three types of electro-chemiluminescence immunoassays recalibrated to the World Health Organization(WHO)standard.The diagnostic accuracy of PSA,%fPSA,and %fPSA in combination with PSA(%fPSA t PSA)was determined using the area under the receiver operating characteristic(ROC)curve(AUC).Results:A total of 2310 consecutive men with PSA levels between 4.0 and 10.0 ng/mL were included,and the detection rate of PCa was 25.1%.The AUC of%fPSA and %fPSA t PSA in predicting any PCa was superior to PSA alone in men aged≥60 years(0.623 vs.0.534,p<0.0001)but not in men aged 40e59 years(0.517 vs.0.518,p=0.939).Similar result was yield in predicting HGPCa.Conclusion:In a clinical setting of Chinese men with 4.0e10.0 ng/mL PSA undergoing initial prostate biopsy,adding %fPSA to PSA can moderately improve the diagnostic accuracy for any PCa and HGPCa compared with PSA alone in patients≥60 but not in patients aged 40-59 years.

Colonoscopy can miss diverticula of the left colon identified by barium enema

AIM: To identify the diagnostic value of colonoscopy for diverticulosis as determined by barium enema. METHODS: A total of 65 patients with hematochezia who underwent colonoscopy and barium enema were analyzed, and the diagnostic value of colonoscopy for diverticula was assessed. The receiver operating characteristic area under the curve was compared in relation to age (< 70 or ≥ 70 years), sex, and colon location. The number of diverticula was counted, and the detection ratio was calculated. RESULTS: Colonic diverticula were observed in 46 patients with barium enema. Colonoscopy had a sensitivity of 91% and specificity of 90%. No significant differences were found in the receiver operating characteristic area under the curve (ROC-AUC) for age group or sex. The ROC-AUC of the left colon was significantly lower than that of the right colon (0.81 vs 0.96, P=0.02). Colonoscopy identified 486 colonic diverticula, while barium enema identified 1186. The detection ratio for the entire colon was therefore 0.41 (486/1186). The detection ratio in the left colon (0.32, 189/588) was significantly lower than that of the right colon (0.50, 297/598) (P < 0.01). CONCLUSION: Compared with barium enema, only half the number of colonic diverticula can be detected by colonoscopy in the entire colon and even less in the left colon.

DETERMINING THICKENER UNDERFLOW CONCENTRATION AND UNIT AREA

ＤＥＴＥＲＭＩＮＩＮＧＴＨＩＣＫＥＮＥＲＵＮＤＥＲＦＬＯＷＣＯＮＣＥＮＴＲＡＴＩＯＮＡＮＤＵＮＩＴＡＲＥＡ￥ＫａｎｇＹｏｎｇ；ＨｕＸｉａｏｍｉｎ；ＤｅｎｇＣｈａｎｇｌｉｅ；ＬｕｏＱｉａｎ（ＤｅｐａｒｔｍｅｎｔｏｆＭｉｎｅｒａｌＥｎｇｉｎｅｅｒｉｎｇ，...