A centrifuge modeling test and a three-dimensional finite element analysis(FEA)of super-long rock-socketed bored pile groups of the Tianxingzhou Bridge are proposed.Based on the similarity theory,different prototypi...A centrifuge modeling test and a three-dimensional finite element analysis(FEA)of super-long rock-socketed bored pile groups of the Tianxingzhou Bridge are proposed.Based on the similarity theory,different prototypical materials are simulated using different indicators in the centrifuge model.The silver sand,the shaft and the pile cap are simulated according to the natural density,the compressive stiffness and the bending stiffness,respectively.The finite element method(FEM)is implemented and analyzed in ANSYS,in which the stress field during the undisturbed soil stage,the boring stage,the concrete-casting stage and the curing stage are discussed in detail.Comparisons in terms of load-settlement,shaft axial force distribution and lateral friction between the numerical results and the test data are carried out to investigate the bearing behaviors of super-long rock-socketed bored pile groups under loading and unloading conditions.Results show that there is a good agreement between the centrifuge modeling tests and the FEM.In addition,the load distribution at the pile top is complicated,which is related to the stiffness of the cap,the corresponding assumptions and the analysis method.The shaft axial force first increases slightly with depth then decreases sharply,and the rate of decrease in rock is greater than that in sand and soil.展开更多
AIM:To conduct a meta-analysis to determine the safety and efficacy of laparoscopic liver resection(LLR) and open liver resection(OLR) for hepatocellular carcinoma(HCC).METHODS:PubMed(Medline),EMBASE and Science Citat...AIM:To conduct a meta-analysis to determine the safety and efficacy of laparoscopic liver resection(LLR) and open liver resection(OLR) for hepatocellular carcinoma(HCC).METHODS:PubMed(Medline),EMBASE and Science Citation Index Expanded and Cochrane Central Register of Controlled Trials in the Cochrane Library were searched systematically to identify relevant comparative studies reporting outcomes for both LLR and OLR for HCC between January 1992 and February 2012.Two authors independently assessed the trials for inclusion and extracted the data.Meta-analysis was performed using Review Manager Version 5.0 software(The Cochrane Collaboration,Oxford,United Kingdom).Pooled odds ratios(OR) or weighted mean differences(WMD) with 95%CI were calculated using either fixed effects(Mantel-Haenszel method) or random effects models(DerSimonian and Laird method).Evaluated endpoints were operative outcomes(operation time,intraoperative blood loss,blood transfusion requirement),postoperative outcomes(liver failure,cirrhotic decompensation/ascites,bile leakage,postoperative bleeding,pulmonary complications,intraabdominal abscess,mortality,hospital stay and oncologic outcomes(positive resection margins and tumor recurrence).RESULTS:Fifteen eligible non-randomized studies were identified,out of which,9 high-quality studies involving 550 patients were included,with 234 patients in the LLR group and 316 patients in the OLR group.LLR was associated with significantly lower intraoperative blood loss,based on six studies with 333 patients [WMD:-129.48 mL;95%CI:-224.76-(-34.21) mL;P = 0.008].Seven studies involving 416 patients were included to assess blood transfusion requirement between the two groups.The LLR group had lower blood transfusion requirement(OR:0.49;95%CI:0.26-0.91;P = 0.02).While analyzing hospital stay,six studies with 333 patients were included.Patients in the LLR group were found to have shorter hospital stay [WMD:-3.19 d;95%CI:-4.09-(-2.28) d;P < 0.00001] than their OLR counterpart.Seven studies including 416 patients were pooled together to estimate the odds of developing postoperative ascites in the patient groups.The LLR group appeared to have a lower incidence of postoperative ascites(OR:0.32;95%CI:0.16-0.61;P = 0.0006) as compared with OLR patients.Similarly,fewer patients had liver failure in the LLR group than in the OLR group(OR:0.15;95%CI:0.02-0.95;P =0.04).However,no significant differences were found between the two approaches with regards to operation time [WMD:4.69 min;95%CI:-22.62-32 min;P = 0.74],bile leakage(OR:0.55;95%CI:0.10-3.12;P = 0.50),postoperative bleeding(OR:0.54;95%CI:0.20-1.45;P = 0.22),pulmonary complications(OR:0.43;95%CI:0.18-1.04;P = 0.06),intra-abdominal abscesses(OR:0.21;95%CI:0.01-4.53;P = 0.32),mortality(OR:0.46;95%CI:0.14-1.51;P = 0.20),presence of positive resection margins(OR:0.59;95%CI:0.21-1.62;P = 0.31) and tumor recurrence(OR:0.95;95%CI:0.62-1.46;P = 0.81).CONCLUSION:LLR appears to be a safe and feasible option for resection of HCC in selected patients based on current evidence.However,further appropriately designed randomized controlled trials should be undertaken to ascertain these findings.展开更多
AIM: To evaluate the clinical outcomes of patients undergoing hepatectomy with hemihepatic vascular occlusion (HHO) compared with total hepatic inflow occlusion (THO). METHODS: Randomized controlled trials (RCT...AIM: To evaluate the clinical outcomes of patients undergoing hepatectomy with hemihepatic vascular occlusion (HHO) compared with total hepatic inflow occlusion (THO). METHODS: Randomized controlled trials (RCTs) co- mparing hemihepatic vascular occlusion and total he- patic inflow occlusion were included by a systematic literature search. Two authors independently assessed the trials for inclusion and extracted the data. A meta- analysis was conducted to estimate blood loss, transfu- sion requirement, and liver injury based on the levels of aspartate aminotransferase (AST) and alanine arni- notransferase (ALT). Either the fixed effects model or random effects model was used. RESULTS- Four RCTs including 338 patients met the predefined inclusion criteria. A total of 167 patients were treated with THO and 171 with HHO. Metaanalysis of AST levels on postoperative day 1 indicated higher levels in the THO group with weighted mean dif- ference (WMD) 342.27; 95% confidence intervals (CI) 217.28-467.26; P = 0.00001; I2 = 16%. Meta-analysis showed no significant difference between THO group and HHO group on blood loss, transfusion requirement, mortality, morbidity, operating time, ischemic duration, hospital stay, ALT levels on postoperative day 1, 3 and 7 and AST levels on postoperative day 3 and 7. CONCLUSION: Hemihepatic vascular occlusion does not offer satisfying benefit to the patients undergoing hepatic resection. However, they have less liver injury after liver resections.展开更多
Based on the similarity theory,a tunnel excavation simulation testing system under typical unsymmetrical loading conditions was established.Using this system,the failure mechanism of surrounding rock of shallow-bias t...Based on the similarity theory,a tunnel excavation simulation testing system under typical unsymmetrical loading conditions was established.Using this system,the failure mechanism of surrounding rock of shallow-bias tunnels with small clear distance was analyzed along with the load characteristics.The results show that:1) The failure process of surrounding rock of shallow-bias tunnels with small clear distance consists of structural and stratum deformation induced by tunnel excavation; Microfracture surfaces are formed in the tunnel surrounding rock and extend deep into the rock mass in a larger density; Tensile cracking occurs in shallow position on the deep-buried side,with shear slip in deep rock mass.In the meantime,rapid deformation and slip take place on the shallow-buried side until the surrounding rocks totally collapse.The production and development of micro-fracture surfaces in the tunnel surrounding rock and tensile cracking in the shallow position on the deep-buried side represent the key stages of failure.2) The final failure mode is featured by an inverted conical fracture with tunnel arch as its top and the slope at tunnel entrance slope as its bottom.The range of failure on the deep-buried side is significantly larger than that on the shallow-buried side.Such difference becomes more prominent with the increasing bias angle.What distinguishes it from the "linear fracture surface" model is that the model proposed has a larger fracture angle on the two sides.Moreover,the bottom of the fracture is located at the springing line of tunnel arch.3) The total vertical load increases with bias angle.Compared with the existing methods,the unsymmetrical loading effect in measurement is more prominent.At last,countermeasures are proposed according to the analysis results: during engineering process,1) The surrounding rock mass on the deep-buried side should be reinforced apart from the tunnel surrounding rock for shallow-buried tunnels with small clear distance; moreover,the scope of consolidation should go beyond the midline of tunnel(along the direction of the top of slope) by 4 excavation spans of single tunnel.2) It is necessary to modify the load value of shallow-bias tunnels with small clear distance.展开更多
Slope failure in loess terrains of Northern China during spring thawing period is closely related to the freeze-thaw cycling that surface soils inevitably experienced. Field surveys were carried out on natural and art...Slope failure in loess terrains of Northern China during spring thawing period is closely related to the freeze-thaw cycling that surface soils inevitably experienced. Field surveys were carried out on natural and artificial slopes in thirteen surveying sites located in the Northern Shaanxi, the center of Loess Plateau, covering five characteristic topographic features including tablelands, ridges, hills, gullies and valleys. Based on the scale that is involved in freeze-thaw cycling, the induced failures can be classified into three main modes, i.e., erosion, peeling and thaw collapse, depending on both high porosity and loose cementation of loess that is easily affected. Model tests on loess slopes with gradients of 53.1°, 45.0° and 33.7° were carried out to reveal the heat transfer, water migration and deformation during slope failure. The surface morphology of slopes was photographed, with flake shaped erosion and cracks noted. For three slope models, time histories for the thermal regime exhibit three obvious cycles of freeze and thaw andthe maximum frost depth develops downwards as freeze-thaw cycling proceeds. Soil water in the unfrozen domain beneath was migrated towards the slope surface, as can be noticed from the considerable change in the unfrozen water content, almost synchronous with the variation of temperature. The displacement in both vertical and horizontal directions varies over time and three obvious cycles can be traced. The residual displacement for each cycle tends to grow and the slopes with higher gradients are more sensitive to potentially sliding during freeze-thaw cycling.展开更多
The Micropile-Mechanically Stabilized Earth(MSE) wall, specially designed for mountain roads, is proposed to improve the MSE wall local stability, global stability and impact resistance of roadside barriers. Model tes...The Micropile-Mechanically Stabilized Earth(MSE) wall, specially designed for mountain roads, is proposed to improve the MSE wall local stability, global stability and impact resistance of roadside barriers. Model tests and the corresponding numerical modeling were conducted to validate the serviceability of the Micropile-MSE wall and the reliability of the numerical method. Then, a parametric study of the stress and deformation of Micropile-MSE wall based on the backfill strength and interfacial friction angle between backfill and backslope is conducted to evaluate its performance.The test results indicate that the surcharge-induced horizontal earth pressure, base pressure and lateral displacement of the wall panel of Micropile-MSE wall decrease. The corresponding numerical results are nearly equal to the measured values. The basic failure mode of MSE wall in steep terrain is the sliding of backfill along the backslope, while A-frame style micropiles are capable of preventing the sliding trend.The maximum resultant displacement can be decreased by 6.25% to 46.9% based on different interfacial friction angles, and the displacement canbe reduced by 6% ~ 56.1% based on different backfill strengths. Furthermore, the reduction increases when the interfacial friction angle and internal friction angle of backfill decrease. In addition, the lateral displacement of wall panel, the deformation of backfill decrease and the tension strain of geogrid obviously, which guarantees the MSE wall functions and provides good conditions for mountain roads.展开更多
AIM:To investigate the effectiveness of 5-flurouracilbased neoadjuvant chemotherapy(NAC) for gastroesophageal and gastric cancer by meta-analysis.METHODS:MEDLINE and manual searches were performed to identify all publ...AIM:To investigate the effectiveness of 5-flurouracilbased neoadjuvant chemotherapy(NAC) for gastroesophageal and gastric cancer by meta-analysis.METHODS:MEDLINE and manual searches were performed to identify all published randomized controlled trials(RCTs) investigating the efficacy of the flurouracilbased NAC for gastroesophageal and gastric cancer,and RCTs of NAC for advanced gastroesophageal and gastric cancer vs no therapy before surgery.Studies that included patients with metastases at enrollment were excluded.Primary endpoint was the odds ratio(OR) for improving overall survival rate of patients with gastroesophageal and gastric cancer.Secondary endpoints were the OR of efficiency for down-staging tumor and increasing R0 resection in patients with gas-troesophageal and gastric cancer.Safety analyses were also performed.The OR was the principal measurement of effect,which was calculated as the treatment group(NAC plus surgery) vs control group(surgery alone) and was presented as a point estimate with 95% confidence intervals(CI).All calculations and statistical tests were performed using RevMan 5.1 software.RESULTS:Seven RCTs were included for the analysis.A total of 1249 patients with advanced gastroesophageal and gastric cancer enrolled in the seven trials were divided into treatment group(n = 620) and control group(n = 629).The quality scores of the RCTs were assessed according to the method of Jadad.The RCT quality scores ranged from 2 to 7(5-point scale),with a mean of 3.75.The median follow-up time in these studies was over 3 years.The meta-analysis showed that NAC improved the overall survival rate(OR 1.40,95%CI 1.11-1.76;P = 0.005),which was statistically significant.The 3-year progression-free survival rate was significantly higher in treatment group than in control group(37.7% vs 27.3%)(OR 1.62,95%CI 1.21-2.15;P = 0.001).The tumor down-stage rate was higher in treatment group than in control group(55.76% vs 41.38%)(OR 1.77,95%CI 1.27-2.49;P = 0.0009) and the R0 resection rate of the gastroesophageal and gastric cancer was higher in treatment group than in control group(75.11% vs 68.56%)(OR 1.38,95%CI 1.03-1.85;P = 0.03),with significant differences.No obvious safety concerns about mortality and complications were raised in these trials.There were no statistically significant differences in perioperative mortality(5.08% vs 4.86%)(OR 1.05,95%CI 0.57-1.94;P = 0.87 fixed-effect model) and in the complication rate between the two groups(13.25% vs 9.66%)(OR 1.40,95%CI 0.91-2.14;P = 0.12 fixed-effect model).Trials showed that patients from Western countries favored NAC compared with those from Asian countries(OR 1.40,95%CI 1.07-1.83).Monotherapy was inferior tomultiple chemotherapy(OR 1.40,95%CI 1.07-1.83).Intravenous administration of NAC was more advantageous than oral route(OR 1.41,95%CI 1.09-1.81).CONCLUSION:Flurouracil-based NAC can safely improve overall survival rate of patients with gastroesophageal/gastric cancer.Additionally,NAC can down the tumor stage and improve R0 resection.展开更多
AIM:To evaluate the comparative therapeutic efficacy of radiofrequency ablation (RFA) and hepatic resection (HR) for solitary colorectal liver metastases (CLM).METHODS:A literature search was performed to identify com...AIM:To evaluate the comparative therapeutic efficacy of radiofrequency ablation (RFA) and hepatic resection (HR) for solitary colorectal liver metastases (CLM).METHODS:A literature search was performed to identify comparative studies reporting outcomes for both RFA and HR for solitary CLM.Pooled odds ratios (OR) with 95% confidence intervals (95% CI) were calculated using either the fixed effects model or random effects model.RESULTS:Seven nonrandomized controlled trials studies were included in this analysis.These studies included a total of 847 patients:273 treated with RFA and 574 treated with HR.The 5 years overall survival rates in the HR group were significantly better than those in the RFA group (OR:0.41,95% CI:0.22-0.90,P=0.008).RFA had a higher rate of local intrahe-patic recurrence compared to HR (OR:4.89,95% CI:1.73-13.87,P=0.003).No differences were found between the two groups with respect to postoperative morbidity and mortality.CONCLUSION:HR was superior to RFA in the treatment of patients with solitary CLM.However,the findings have to be carefully interpreted due to the lower level of evidence.展开更多
AIM:To evaluate the feasibility and safety of laparoscopic distal pancreatectomy(LDP) compared with open distal pancreatectomy(ODP).METHODS:Meta-analysis was performed using the databases,including PubMed,the Cochrane...AIM:To evaluate the feasibility and safety of laparoscopic distal pancreatectomy(LDP) compared with open distal pancreatectomy(ODP).METHODS:Meta-analysis was performed using the databases,including PubMed,the Cochrane Central Register of Controlled Trials,Web of Science and BIOSIS Previews.Articles should contain quantitative data of the comparison of LDP and ODP.Each article was reviewed by two authors.Indices of operative time,spleen-preserving rate,time to fluid intake,ratio of malignant tumors,postoperative hospital stay,incidence rate of pancreatic fistula and overall morbidity rate were analyzed.RESULTS:Nine articles with 1341 patients who underwent pancreatectomy met the inclusion criteria.LDP was performed in 501(37.4%) patients,while ODP was performed in 840(62.6%) patients.There were significant differences in the operative time,time to fluid intake,postoperative hospital stay and spleen-preserving rate between LDP and ODP.There was no difference between the two groups in pancreatic fistula rate [random effects model,risk ratio(RR) 0.996(0.663,1.494),P = 0.983,I2 = 28.4%] and overall morbidity rate [random effects model,RR 0.81(0.596,1.101),P = 0.178,I2 = 55.6%].CONCLUSION:LDP has the advantages of shorter hospital stay and operative time,more rapid recovery and higher spleen-preserving rate as compared with ODP.展开更多
Earthquake-induced landslides along the Dujiangyan-Yingxiu highway after the Ms 8.0 Wenchuan earthquake in 2008 were investigated. It was found that: (1) slopes were shattered and damaged during the earthquake a...Earthquake-induced landslides along the Dujiangyan-Yingxiu highway after the Ms 8.0 Wenchuan earthquake in 2008 were investigated. It was found that: (1) slopes were shattered and damaged during the earthquake and open tension cracks formed on the tops of the slopes; (2) the upper parts of slopes collapsed and slid, while the lower parts remained basically intact, indicating that the upper parts of slopes would be damaged more heavily than the lower parts during an earthquake. Large-scale shaking table model tests were conducted to study failure behavior of slopes under the Wenchuan seismic wave, which reproduced the process of deformation and failure of slopes. Tension cracks emerged at the top and upper part of model, while the bottom of the model remained intact, consistent with field investigations. Depth of the tension crack at the top of model is 32 cm, i.e., 3.2 m compared to the prototype natural slope with a height of 14 m when the length scale ratio (proto/model) is lo. Acceleration at the top of the slope was almost twice as large as that at the toe when the measured accelerations on shaking table are 4.85 m/s2 and 6.49 m/s2, which means that seismic force at the top of the slope is twice the magnitude of that at the toe. By use of the dynamic-strength-reduction method, numerical simulation was conducted to explore the process and mechanism of formation of the sliding surface, with other quantified information. The earthquake-induced failure surfaces commonly consist of tension cracks and shear zones. Within 5 mfrom the top of the slope, the dynamic sliding surface will be about 1 m shallower than the pseudo-static sliding surface in a horizontal direction when the peak ground acceleration (PGA) is 1 m/s2; the dynamic sliding surface will be about 2 m deeper than the pseudo-static sliding surface in a horizontal direction when the PGA is lo m/sL and the depths of the dynamic sliding surface and the pseudo-static sliding surface will be almost the same when the PGA is 2 m/s2. Based on these findings, it is suggested that the key point of anti-seismic design, as well as for mitigation of post-earthquake, secondary mountain hazards, is to prevent tension cracks from forming in the upper part of the slope. Therefore, the depth of tension cracks in slope surfaces is the key to reinforcement of slopes. The depth of the sliding surface from the pseudo-static method can be a reference for slope reinforcement mitigation.展开更多
AIM:To evaluate the therapeutic effects of itopride vs other drugs(placebo,domperidone,mosapride) for functional dyspepsia(FD).METHODS:Randomized controlled trials(RCTs) of itopride for FD were retrieved from database...AIM:To evaluate the therapeutic effects of itopride vs other drugs(placebo,domperidone,mosapride) for functional dyspepsia(FD).METHODS:Randomized controlled trials(RCTs) of itopride for FD were retrieved from databases.Relevant information was extracted and analyzed,using the relative risk(RR) and weighted mean deviation,as appropriate.A random or fixed effect model was used,based on the heterogeneity of the included articles,and visual inspection of funnel plots was used to evaluate publication bias.RESULTS:Nine RCTs enrolling 2620 FD cases were included;1372 cases received itopride treatment and 1248 cases received placebo or other drugs(control groups).Compared with control groups,itopride had superior RR values of 1.11 [95%CI:(1.03,1.19),P = 0.006],1.21 [95%CI:(1.03,1.44),P = 0.02],and1.24 [95%CI:(1.01,1.53),P = 0.04] for global patient assessment,postprandial fullness,and early satiety,respectively.For the Leeds Dyspepsia Questionnaire score,the weighted mean deviation was-1.38 [95%CI:(-1.75,-1.01),P < 0.01].The incidence of adverse effects was similar in the itopride and control groups.The funnel plots for all indicators showed no evidence of publication bias.CONCLUSION:Itopride has good efficacy in terms of global patients assessment,postprandial fullness,and early satiety in the treatment of patients with FD and shows a low rate of adverse reactions.Itopride can greatly improve FD syndromes-score.展开更多
Accurately identifying network traffics at the early stage is very important for the application of traffic identification.Recent years,more and more research works have tried to build effective machine learning model...Accurately identifying network traffics at the early stage is very important for the application of traffic identification.Recent years,more and more research works have tried to build effective machine learning models to identify traffics with the few packets at the early stage.However,a basic and important problem is still unresolved,that is how many packets are most effective in early stage traffic identification.In this paper,we try to resolve this problem using experimental methods.We firstly extract the packet size of the first 2-10 packets of 3 traffic data sets.And then execute crossover identification experiments with different numbers of packets using 11 well-known machine learning classifiers.Finally,statistical tests are applied to find out which number is the best performed one.Our experimental results show that 5-7are the best packet numbers for early stage traffic identification.展开更多
In this paper, we conduct research on the computer network protocol test model based on genetic and random walk algorithm.Network protocol is the abstract concept, is important in the process of the development of net...In this paper, we conduct research on the computer network protocol test model based on genetic and random walk algorithm.Network protocol is the abstract concept, is important in the process of the development of network system. Fully understand and grasp of thenetwork protocols for managers is there is a big diffi cult. Network covert channel is the evaluation of intrusion detection system and fi rewallsecurity performance of an important means, the paper will start from the angle of the attacker, the fl aws of the research, and use this kind ofdefect to realize network covert channel, the random walk algorithm will be feasible for dealing with this issue. For achieving this, we integratethe genetic and random walk algorithm for systematic optimization.展开更多
This paper describes the applicability of a stochastic model to the numerical experiments of thermal convection carried out under the condition of the northern part of Lake Biwa, Shiga Prefecture, Japan. It was shown ...This paper describes the applicability of a stochastic model to the numerical experiments of thermal convection carried out under the condition of the northern part of Lake Biwa, Shiga Prefecture, Japan. It was shown in the previous study that the temporal changes of vertical water temperature distributions during the cooling period between September and February can be reproduced by a simple 3D-CFD model. It was also pointed out that the spatial distributions of cooled water body sinking to the bottom due to water surface cooling represent similar features of forest gap distribution, which can be clarified by a stochastic model. The basic features of numerical experiments on thermal convection such as the spatial distribution of cooled water body are firstly shown with several cooling rates at water surface. Then, a stochastic model, which was originally introduced to explain forest gap dynamics, is shown with its MFA (mean field approximation) as first approximation of stochastic model. It is pointed out through the comparison of theoretical results by MFA with tuned model constants to numerical experiments that MFA with some refinement can be applicable to reproduce the basic features of simulated results to some extent, although further investigations are required to clarify the applicability of the model to more detailed mechanism of thermal convection such as size distribution of cooled water body, phase change of flow pattern, etc..展开更多
OBJECTIVE Ginsenoside Rg3 (Rg3) has shown anti-tumor effects on various tumor cells. It has been widely used in China for non-small cell lung cancer (NSCLC). However, there are only a few clinical trials to study ...OBJECTIVE Ginsenoside Rg3 (Rg3) has shown anti-tumor effects on various tumor cells. It has been widely used in China for non-small cell lung cancer (NSCLC). However, there are only a few clinical trials to study the effectiveness of Rg3 on NSCLC, and almost them are small- samples, so we performed a meta-analysis on the results of the studies we collected in order to investigate the effectiveness of Rg3 on NSCLC. METHODS A meta-analysis was conducted in all the selected randomized controlled trials evaluating the effectiveness of Rg3 on NSCLC patients. All on-line databases regarding Rg3 from 1950 to 2011 were searched. Supplemental hand searching of the references of retrieved articles was performed. RESULTS Six trials met the inclusion criteria. Four of them compared chemotherapy plus Rg3 with chemotherapy alone, and the other 2 compared chemotherapy plus Rg3 with chemotherapy plus placebo. These trials are homogeneous. Two of the trials report overall survival, but the data are not suitable for a meta-analysis. After meta-analysis was conducted in the included studies comparing the effects of chemotherapy plus Rg3 with that of chemotherapy alone or chemotherapy plus placebo, it was suggested that chemotherapy plus Rg3 increased the response rate [odds ratio: 2.64 (95% Ch 1.70-4.11), fixed effects model] and disease control rate [odds ratio: 3.34 (95% CI: 1.92-5.81); fixed effects model] of the patients at stage II-IV, especially for the patients at stage Ill-IV. CONCLUSION Meta-analysis of the available evidence suggests that Rg3 plus chemotherapy improves the response rate of NSCLC patients, and well-designed RCTs with large sample size are needed.展开更多
The primary aim of clinical trials is to investigate whether a treatment is effective for a particular disease or condition. Randomized controlled clinical trials are considered to be the gold standard for evaluating ...The primary aim of clinical trials is to investigate whether a treatment is effective for a particular disease or condition. Randomized controlled clinical trials are considered to be the gold standard for evaluating the effect of a certain intervention. However, in clinical trials, even after randomization, there are situations where the patients differ substantially with respect to the baseline value of the outcome variable. Many a times the response to interventions depends on the baseline values of the outcome variable. When there are baseline-dependent treatment effects, differences among treatments vary as a function of baseline level. Although variation in outcome associated with baseline value is accounted for in ANCOVA, analysis of individual differences in treatment effect is precluded by the homogeneity of regression assumption. This assumption requires that expected differences in outcome among treatments be constant across all baseline levels. To overcome this difficulty, Weigel and Narvaez [7] proposed a regression model for two treatment groups to analyze individual response to treatments in randomized controlled clinical trials. The authors reviewed the model suggested by Weigel and Narvaez and extended further for three or more treatment groups. The utility of the model was demonstrated with real life data from a randomized controlled clinical trial of bronchial asthma.展开更多
Objective: The efficacy of preoperative transarterial chemoembolization(TACE) for hepatectomy on hepatocelluar carcinoma(HCC) is still controversial. This study aims to evaluate the efficacy of preoperative TACE on re...Objective: The efficacy of preoperative transarterial chemoembolization(TACE) for hepatectomy on hepatocelluar carcinoma(HCC) is still controversial. This study aims to evaluate the efficacy of preoperative TACE on resectable HCC. Methods: Pubmed, SCI, Medline, EMBASE, Cochrane Datebase, CNKI were searched. The articles that focused on preoperative TACE for resectable HCC, published from 1990 to 2012, were collected by computerized search of literatures and manual search of bibliographies. The relevant clinical trials' data were reviewed by meta-analysis using the random effects model or fixed effect model by heterogeneity. The outcomes were expressed as odds ratio(OR) with 95% confidence intervals(CIs). Results: A total of 1347 patients were included in these 7 studies, the cases were divided into the preoperative TACE group and the non-preoperative TACE group, and there was no difference between the two groups in the 3-year disease-free survival rate, with an odds ratio of 1.14(95% CI = 0.90–1.45, P = 0.27); the 5-year disease-free survival rate in the preoperative TACE group was better than that in the non-TACE group with an odds ratio of 1.35(95% CI = 1.07–1.74, P = 0.02); the 5-year overall survival rate in the preoperative TACE group was higher than that in the non-TACE group with an odds ratio of 0.59(95% CI = 0.46–0.77, P < 0.0001). Conclusion: The present data suggests that preoperative TACE has no different in improving the 3-year disease-free survival rate with non-TACE group for resectable HCC, while it can improve the 5-year disease-free survival rate and the 5-year overall survival rate. More randomized controlled trials using large sample size are needed to provide sufficient evidence to confirm current conclusion.展开更多
Objective: The aim of this study was to compare the efficacy in alleviating the endotracheal tube related discomfort and the safetyof intracufflidocaine (in different forms) with air and/or normal saline (NS) dur...Objective: The aim of this study was to compare the efficacy in alleviating the endotracheal tube related discomfort and the safetyof intracufflidocaine (in different forms) with air and/or normal saline (NS) during general anesthesia with tracheal intubation. Methods: Cochrane Central Register of Controlled Trials, PubMed and Embase were searched for relevant studies. Thirteen randomized, controlled trials involving 1 010 patients were ultimately identified. A meta-analysis of all randomized controlled trials fulfilling the predefined criteria was performed. Random-effect model and subgroup studies were used when significant heterogeneity existed among those trials. Results: Compared with air and NS, intracufflidocaine could significantly alleviate the severity of sore throat at different time points (15min, 30min, lh, 2h, 3h, 6h, 12h and 24h aiter extubation) and the occurrence of cough, restlessness, postoperative nausea and vomiting, dysphonia and hoarseness. Besides intracufflidocaine brought about a significant prolongation of spontaneous ventilation time. It was worth mentioning that, compared withlidocaine or its hydrochloride form, alkalinized lidocainewas much more efficient in reducing the severity of sore throat and prolonging spontaneous ventilation time. Conclusion: The present meta-analysis indicates that intracuttlidocaine can significantly improve endotracheal tube tolerance and this improvement can be strengthened by alkalinization of lidocaine.展开更多
基金The Natural Science Foundation of Hubei Province(No.2007ABA094)
文摘A centrifuge modeling test and a three-dimensional finite element analysis(FEA)of super-long rock-socketed bored pile groups of the Tianxingzhou Bridge are proposed.Based on the similarity theory,different prototypical materials are simulated using different indicators in the centrifuge model.The silver sand,the shaft and the pile cap are simulated according to the natural density,the compressive stiffness and the bending stiffness,respectively.The finite element method(FEM)is implemented and analyzed in ANSYS,in which the stress field during the undisturbed soil stage,the boring stage,the concrete-casting stage and the curing stage are discussed in detail.Comparisons in terms of load-settlement,shaft axial force distribution and lateral friction between the numerical results and the test data are carried out to investigate the bearing behaviors of super-long rock-socketed bored pile groups under loading and unloading conditions.Results show that there is a good agreement between the centrifuge modeling tests and the FEM.In addition,the load distribution at the pile top is complicated,which is related to the stiffness of the cap,the corresponding assumptions and the analysis method.The shaft axial force first increases slightly with depth then decreases sharply,and the rate of decrease in rock is greater than that in sand and soil.
文摘AIM:To conduct a meta-analysis to determine the safety and efficacy of laparoscopic liver resection(LLR) and open liver resection(OLR) for hepatocellular carcinoma(HCC).METHODS:PubMed(Medline),EMBASE and Science Citation Index Expanded and Cochrane Central Register of Controlled Trials in the Cochrane Library were searched systematically to identify relevant comparative studies reporting outcomes for both LLR and OLR for HCC between January 1992 and February 2012.Two authors independently assessed the trials for inclusion and extracted the data.Meta-analysis was performed using Review Manager Version 5.0 software(The Cochrane Collaboration,Oxford,United Kingdom).Pooled odds ratios(OR) or weighted mean differences(WMD) with 95%CI were calculated using either fixed effects(Mantel-Haenszel method) or random effects models(DerSimonian and Laird method).Evaluated endpoints were operative outcomes(operation time,intraoperative blood loss,blood transfusion requirement),postoperative outcomes(liver failure,cirrhotic decompensation/ascites,bile leakage,postoperative bleeding,pulmonary complications,intraabdominal abscess,mortality,hospital stay and oncologic outcomes(positive resection margins and tumor recurrence).RESULTS:Fifteen eligible non-randomized studies were identified,out of which,9 high-quality studies involving 550 patients were included,with 234 patients in the LLR group and 316 patients in the OLR group.LLR was associated with significantly lower intraoperative blood loss,based on six studies with 333 patients [WMD:-129.48 mL;95%CI:-224.76-(-34.21) mL;P = 0.008].Seven studies involving 416 patients were included to assess blood transfusion requirement between the two groups.The LLR group had lower blood transfusion requirement(OR:0.49;95%CI:0.26-0.91;P = 0.02).While analyzing hospital stay,six studies with 333 patients were included.Patients in the LLR group were found to have shorter hospital stay [WMD:-3.19 d;95%CI:-4.09-(-2.28) d;P < 0.00001] than their OLR counterpart.Seven studies including 416 patients were pooled together to estimate the odds of developing postoperative ascites in the patient groups.The LLR group appeared to have a lower incidence of postoperative ascites(OR:0.32;95%CI:0.16-0.61;P = 0.0006) as compared with OLR patients.Similarly,fewer patients had liver failure in the LLR group than in the OLR group(OR:0.15;95%CI:0.02-0.95;P =0.04).However,no significant differences were found between the two approaches with regards to operation time [WMD:4.69 min;95%CI:-22.62-32 min;P = 0.74],bile leakage(OR:0.55;95%CI:0.10-3.12;P = 0.50),postoperative bleeding(OR:0.54;95%CI:0.20-1.45;P = 0.22),pulmonary complications(OR:0.43;95%CI:0.18-1.04;P = 0.06),intra-abdominal abscesses(OR:0.21;95%CI:0.01-4.53;P = 0.32),mortality(OR:0.46;95%CI:0.14-1.51;P = 0.20),presence of positive resection margins(OR:0.59;95%CI:0.21-1.62;P = 0.31) and tumor recurrence(OR:0.95;95%CI:0.62-1.46;P = 0.81).CONCLUSION:LLR appears to be a safe and feasible option for resection of HCC in selected patients based on current evidence.However,further appropriately designed randomized controlled trials should be undertaken to ascertain these findings.
文摘AIM: To evaluate the clinical outcomes of patients undergoing hepatectomy with hemihepatic vascular occlusion (HHO) compared with total hepatic inflow occlusion (THO). METHODS: Randomized controlled trials (RCTs) co- mparing hemihepatic vascular occlusion and total he- patic inflow occlusion were included by a systematic literature search. Two authors independently assessed the trials for inclusion and extracted the data. A meta- analysis was conducted to estimate blood loss, transfu- sion requirement, and liver injury based on the levels of aspartate aminotransferase (AST) and alanine arni- notransferase (ALT). Either the fixed effects model or random effects model was used. RESULTS- Four RCTs including 338 patients met the predefined inclusion criteria. A total of 167 patients were treated with THO and 171 with HHO. Metaanalysis of AST levels on postoperative day 1 indicated higher levels in the THO group with weighted mean dif- ference (WMD) 342.27; 95% confidence intervals (CI) 217.28-467.26; P = 0.00001; I2 = 16%. Meta-analysis showed no significant difference between THO group and HHO group on blood loss, transfusion requirement, mortality, morbidity, operating time, ischemic duration, hospital stay, ALT levels on postoperative day 1, 3 and 7 and AST levels on postoperative day 3 and 7. CONCLUSION: Hemihepatic vascular occlusion does not offer satisfying benefit to the patients undergoing hepatic resection. However, they have less liver injury after liver resections.
基金Project(51508575)supported by the National Natural Science Foundation of ChinaProject(2011CB013802)supported by the National Basic Research Program of China+1 种基金Projects(2014M560652,2016T90764)supported by the China Postdoctoral Science FoundationProject(2015RS4006)supported by the Innovative Talents of Science and Technology Plan of Hunan Province,China
文摘Based on the similarity theory,a tunnel excavation simulation testing system under typical unsymmetrical loading conditions was established.Using this system,the failure mechanism of surrounding rock of shallow-bias tunnels with small clear distance was analyzed along with the load characteristics.The results show that:1) The failure process of surrounding rock of shallow-bias tunnels with small clear distance consists of structural and stratum deformation induced by tunnel excavation; Microfracture surfaces are formed in the tunnel surrounding rock and extend deep into the rock mass in a larger density; Tensile cracking occurs in shallow position on the deep-buried side,with shear slip in deep rock mass.In the meantime,rapid deformation and slip take place on the shallow-buried side until the surrounding rocks totally collapse.The production and development of micro-fracture surfaces in the tunnel surrounding rock and tensile cracking in the shallow position on the deep-buried side represent the key stages of failure.2) The final failure mode is featured by an inverted conical fracture with tunnel arch as its top and the slope at tunnel entrance slope as its bottom.The range of failure on the deep-buried side is significantly larger than that on the shallow-buried side.Such difference becomes more prominent with the increasing bias angle.What distinguishes it from the "linear fracture surface" model is that the model proposed has a larger fracture angle on the two sides.Moreover,the bottom of the fracture is located at the springing line of tunnel arch.3) The total vertical load increases with bias angle.Compared with the existing methods,the unsymmetrical loading effect in measurement is more prominent.At last,countermeasures are proposed according to the analysis results: during engineering process,1) The surrounding rock mass on the deep-buried side should be reinforced apart from the tunnel surrounding rock for shallow-buried tunnels with small clear distance; moreover,the scope of consolidation should go beyond the midline of tunnel(along the direction of the top of slope) by 4 excavation spans of single tunnel.2) It is necessary to modify the load value of shallow-bias tunnels with small clear distance.
基金financially supported by the National Natural Science Foundation of China (Grant Nos. 51478385, 51208409, 51778528 and 51408486)
文摘Slope failure in loess terrains of Northern China during spring thawing period is closely related to the freeze-thaw cycling that surface soils inevitably experienced. Field surveys were carried out on natural and artificial slopes in thirteen surveying sites located in the Northern Shaanxi, the center of Loess Plateau, covering five characteristic topographic features including tablelands, ridges, hills, gullies and valleys. Based on the scale that is involved in freeze-thaw cycling, the induced failures can be classified into three main modes, i.e., erosion, peeling and thaw collapse, depending on both high porosity and loose cementation of loess that is easily affected. Model tests on loess slopes with gradients of 53.1°, 45.0° and 33.7° were carried out to reveal the heat transfer, water migration and deformation during slope failure. The surface morphology of slopes was photographed, with flake shaped erosion and cracks noted. For three slope models, time histories for the thermal regime exhibit three obvious cycles of freeze and thaw andthe maximum frost depth develops downwards as freeze-thaw cycling proceeds. Soil water in the unfrozen domain beneath was migrated towards the slope surface, as can be noticed from the considerable change in the unfrozen water content, almost synchronous with the variation of temperature. The displacement in both vertical and horizontal directions varies over time and three obvious cycles can be traced. The residual displacement for each cycle tends to grow and the slopes with higher gradients are more sensitive to potentially sliding during freeze-thaw cycling.
基金sponsored by Colorado Department of Transportation (CDOT Award No. 12 HAA 38229) to R.Y.S.P.partial funding was received by Z.Z. from the National Natural Science Foundation of China (Grant No. 51379067, 51609040, 51420105013)+3 种基金the Natural Science Foundation of Fujian Province (Grant No. 2016J05112)Science and Technology Project of Bureau of Geology and Mineral Resources of Fujian Province (DK2016014)the Natural Science Foundation of Fujian Province (Grant No. 2015J01158)the Fundamental Research Funds for the Central Universities (Grant No. 2015B17314)
文摘The Micropile-Mechanically Stabilized Earth(MSE) wall, specially designed for mountain roads, is proposed to improve the MSE wall local stability, global stability and impact resistance of roadside barriers. Model tests and the corresponding numerical modeling were conducted to validate the serviceability of the Micropile-MSE wall and the reliability of the numerical method. Then, a parametric study of the stress and deformation of Micropile-MSE wall based on the backfill strength and interfacial friction angle between backfill and backslope is conducted to evaluate its performance.The test results indicate that the surcharge-induced horizontal earth pressure, base pressure and lateral displacement of the wall panel of Micropile-MSE wall decrease. The corresponding numerical results are nearly equal to the measured values. The basic failure mode of MSE wall in steep terrain is the sliding of backfill along the backslope, while A-frame style micropiles are capable of preventing the sliding trend.The maximum resultant displacement can be decreased by 6.25% to 46.9% based on different interfacial friction angles, and the displacement canbe reduced by 6% ~ 56.1% based on different backfill strengths. Furthermore, the reduction increases when the interfacial friction angle and internal friction angle of backfill decrease. In addition, the lateral displacement of wall panel, the deformation of backfill decrease and the tension strain of geogrid obviously, which guarantees the MSE wall functions and provides good conditions for mountain roads.
文摘AIM:To investigate the effectiveness of 5-flurouracilbased neoadjuvant chemotherapy(NAC) for gastroesophageal and gastric cancer by meta-analysis.METHODS:MEDLINE and manual searches were performed to identify all published randomized controlled trials(RCTs) investigating the efficacy of the flurouracilbased NAC for gastroesophageal and gastric cancer,and RCTs of NAC for advanced gastroesophageal and gastric cancer vs no therapy before surgery.Studies that included patients with metastases at enrollment were excluded.Primary endpoint was the odds ratio(OR) for improving overall survival rate of patients with gastroesophageal and gastric cancer.Secondary endpoints were the OR of efficiency for down-staging tumor and increasing R0 resection in patients with gas-troesophageal and gastric cancer.Safety analyses were also performed.The OR was the principal measurement of effect,which was calculated as the treatment group(NAC plus surgery) vs control group(surgery alone) and was presented as a point estimate with 95% confidence intervals(CI).All calculations and statistical tests were performed using RevMan 5.1 software.RESULTS:Seven RCTs were included for the analysis.A total of 1249 patients with advanced gastroesophageal and gastric cancer enrolled in the seven trials were divided into treatment group(n = 620) and control group(n = 629).The quality scores of the RCTs were assessed according to the method of Jadad.The RCT quality scores ranged from 2 to 7(5-point scale),with a mean of 3.75.The median follow-up time in these studies was over 3 years.The meta-analysis showed that NAC improved the overall survival rate(OR 1.40,95%CI 1.11-1.76;P = 0.005),which was statistically significant.The 3-year progression-free survival rate was significantly higher in treatment group than in control group(37.7% vs 27.3%)(OR 1.62,95%CI 1.21-2.15;P = 0.001).The tumor down-stage rate was higher in treatment group than in control group(55.76% vs 41.38%)(OR 1.77,95%CI 1.27-2.49;P = 0.0009) and the R0 resection rate of the gastroesophageal and gastric cancer was higher in treatment group than in control group(75.11% vs 68.56%)(OR 1.38,95%CI 1.03-1.85;P = 0.03),with significant differences.No obvious safety concerns about mortality and complications were raised in these trials.There were no statistically significant differences in perioperative mortality(5.08% vs 4.86%)(OR 1.05,95%CI 0.57-1.94;P = 0.87 fixed-effect model) and in the complication rate between the two groups(13.25% vs 9.66%)(OR 1.40,95%CI 0.91-2.14;P = 0.12 fixed-effect model).Trials showed that patients from Western countries favored NAC compared with those from Asian countries(OR 1.40,95%CI 1.07-1.83).Monotherapy was inferior tomultiple chemotherapy(OR 1.40,95%CI 1.07-1.83).Intravenous administration of NAC was more advantageous than oral route(OR 1.41,95%CI 1.09-1.81).CONCLUSION:Flurouracil-based NAC can safely improve overall survival rate of patients with gastroesophageal/gastric cancer.Additionally,NAC can down the tumor stage and improve R0 resection.
文摘AIM:To evaluate the comparative therapeutic efficacy of radiofrequency ablation (RFA) and hepatic resection (HR) for solitary colorectal liver metastases (CLM).METHODS:A literature search was performed to identify comparative studies reporting outcomes for both RFA and HR for solitary CLM.Pooled odds ratios (OR) with 95% confidence intervals (95% CI) were calculated using either the fixed effects model or random effects model.RESULTS:Seven nonrandomized controlled trials studies were included in this analysis.These studies included a total of 847 patients:273 treated with RFA and 574 treated with HR.The 5 years overall survival rates in the HR group were significantly better than those in the RFA group (OR:0.41,95% CI:0.22-0.90,P=0.008).RFA had a higher rate of local intrahe-patic recurrence compared to HR (OR:4.89,95% CI:1.73-13.87,P=0.003).No differences were found between the two groups with respect to postoperative morbidity and mortality.CONCLUSION:HR was superior to RFA in the treatment of patients with solitary CLM.However,the findings have to be carefully interpreted due to the lower level of evidence.
基金Supported by The key project grant from the Science and Technology Department of Zhejiang Province,No.2011C13036-2
文摘AIM:To evaluate the feasibility and safety of laparoscopic distal pancreatectomy(LDP) compared with open distal pancreatectomy(ODP).METHODS:Meta-analysis was performed using the databases,including PubMed,the Cochrane Central Register of Controlled Trials,Web of Science and BIOSIS Previews.Articles should contain quantitative data of the comparison of LDP and ODP.Each article was reviewed by two authors.Indices of operative time,spleen-preserving rate,time to fluid intake,ratio of malignant tumors,postoperative hospital stay,incidence rate of pancreatic fistula and overall morbidity rate were analyzed.RESULTS:Nine articles with 1341 patients who underwent pancreatectomy met the inclusion criteria.LDP was performed in 501(37.4%) patients,while ODP was performed in 840(62.6%) patients.There were significant differences in the operative time,time to fluid intake,postoperative hospital stay and spleen-preserving rate between LDP and ODP.There was no difference between the two groups in pancreatic fistula rate [random effects model,risk ratio(RR) 0.996(0.663,1.494),P = 0.983,I2 = 28.4%] and overall morbidity rate [random effects model,RR 0.81(0.596,1.101),P = 0.178,I2 = 55.6%].CONCLUSION:LDP has the advantages of shorter hospital stay and operative time,more rapid recovery and higher spleen-preserving rate as compared with ODP.
基金supported by 973 Program,Grant No. 2008CB425802National Natural Science Foundation of Chinasupported by the Fundamental Research Funds for the Central Universities (SWJTU09ZT04)
文摘Earthquake-induced landslides along the Dujiangyan-Yingxiu highway after the Ms 8.0 Wenchuan earthquake in 2008 were investigated. It was found that: (1) slopes were shattered and damaged during the earthquake and open tension cracks formed on the tops of the slopes; (2) the upper parts of slopes collapsed and slid, while the lower parts remained basically intact, indicating that the upper parts of slopes would be damaged more heavily than the lower parts during an earthquake. Large-scale shaking table model tests were conducted to study failure behavior of slopes under the Wenchuan seismic wave, which reproduced the process of deformation and failure of slopes. Tension cracks emerged at the top and upper part of model, while the bottom of the model remained intact, consistent with field investigations. Depth of the tension crack at the top of model is 32 cm, i.e., 3.2 m compared to the prototype natural slope with a height of 14 m when the length scale ratio (proto/model) is lo. Acceleration at the top of the slope was almost twice as large as that at the toe when the measured accelerations on shaking table are 4.85 m/s2 and 6.49 m/s2, which means that seismic force at the top of the slope is twice the magnitude of that at the toe. By use of the dynamic-strength-reduction method, numerical simulation was conducted to explore the process and mechanism of formation of the sliding surface, with other quantified information. The earthquake-induced failure surfaces commonly consist of tension cracks and shear zones. Within 5 mfrom the top of the slope, the dynamic sliding surface will be about 1 m shallower than the pseudo-static sliding surface in a horizontal direction when the peak ground acceleration (PGA) is 1 m/s2; the dynamic sliding surface will be about 2 m deeper than the pseudo-static sliding surface in a horizontal direction when the PGA is lo m/sL and the depths of the dynamic sliding surface and the pseudo-static sliding surface will be almost the same when the PGA is 2 m/s2. Based on these findings, it is suggested that the key point of anti-seismic design, as well as for mitigation of post-earthquake, secondary mountain hazards, is to prevent tension cracks from forming in the upper part of the slope. Therefore, the depth of tension cracks in slope surfaces is the key to reinforcement of slopes. The depth of the sliding surface from the pseudo-static method can be a reference for slope reinforcement mitigation.
基金Supported by The Natural Science Foundation of Zhejiang Province of China,No. LY12H29002Traditional Chinese Medicine Science Foundation of Zhejiang Province of China,No. 2011ZB032
文摘AIM:To evaluate the therapeutic effects of itopride vs other drugs(placebo,domperidone,mosapride) for functional dyspepsia(FD).METHODS:Randomized controlled trials(RCTs) of itopride for FD were retrieved from databases.Relevant information was extracted and analyzed,using the relative risk(RR) and weighted mean deviation,as appropriate.A random or fixed effect model was used,based on the heterogeneity of the included articles,and visual inspection of funnel plots was used to evaluate publication bias.RESULTS:Nine RCTs enrolling 2620 FD cases were included;1372 cases received itopride treatment and 1248 cases received placebo or other drugs(control groups).Compared with control groups,itopride had superior RR values of 1.11 [95%CI:(1.03,1.19),P = 0.006],1.21 [95%CI:(1.03,1.44),P = 0.02],and1.24 [95%CI:(1.01,1.53),P = 0.04] for global patient assessment,postprandial fullness,and early satiety,respectively.For the Leeds Dyspepsia Questionnaire score,the weighted mean deviation was-1.38 [95%CI:(-1.75,-1.01),P < 0.01].The incidence of adverse effects was similar in the itopride and control groups.The funnel plots for all indicators showed no evidence of publication bias.CONCLUSION:Itopride has good efficacy in terms of global patients assessment,postprandial fullness,and early satiety in the treatment of patients with FD and shows a low rate of adverse reactions.Itopride can greatly improve FD syndromes-score.
基金This research was partially supported by National Natural Science Foundation of China under grant No.61472164,No.61402475,No.61173078,No.61203105,No.61173079,No.61070130,and No.60903176,the Provincial Natural Science Foundation of Shandong under grant No.ZR2012FM010,No.ZR2011FZ001,No.ZR2010FM047,No.ZR2010FQ028 and No.ZR2012FQ016
文摘Accurately identifying network traffics at the early stage is very important for the application of traffic identification.Recent years,more and more research works have tried to build effective machine learning models to identify traffics with the few packets at the early stage.However,a basic and important problem is still unresolved,that is how many packets are most effective in early stage traffic identification.In this paper,we try to resolve this problem using experimental methods.We firstly extract the packet size of the first 2-10 packets of 3 traffic data sets.And then execute crossover identification experiments with different numbers of packets using 11 well-known machine learning classifiers.Finally,statistical tests are applied to find out which number is the best performed one.Our experimental results show that 5-7are the best packet numbers for early stage traffic identification.
文摘In this paper, we conduct research on the computer network protocol test model based on genetic and random walk algorithm.Network protocol is the abstract concept, is important in the process of the development of network system. Fully understand and grasp of thenetwork protocols for managers is there is a big diffi cult. Network covert channel is the evaluation of intrusion detection system and fi rewallsecurity performance of an important means, the paper will start from the angle of the attacker, the fl aws of the research, and use this kind ofdefect to realize network covert channel, the random walk algorithm will be feasible for dealing with this issue. For achieving this, we integratethe genetic and random walk algorithm for systematic optimization.
文摘This paper describes the applicability of a stochastic model to the numerical experiments of thermal convection carried out under the condition of the northern part of Lake Biwa, Shiga Prefecture, Japan. It was shown in the previous study that the temporal changes of vertical water temperature distributions during the cooling period between September and February can be reproduced by a simple 3D-CFD model. It was also pointed out that the spatial distributions of cooled water body sinking to the bottom due to water surface cooling represent similar features of forest gap distribution, which can be clarified by a stochastic model. The basic features of numerical experiments on thermal convection such as the spatial distribution of cooled water body are firstly shown with several cooling rates at water surface. Then, a stochastic model, which was originally introduced to explain forest gap dynamics, is shown with its MFA (mean field approximation) as first approximation of stochastic model. It is pointed out through the comparison of theoretical results by MFA with tuned model constants to numerical experiments that MFA with some refinement can be applicable to reproduce the basic features of simulated results to some extent, although further investigations are required to clarify the applicability of the model to more detailed mechanism of thermal convection such as size distribution of cooled water body, phase change of flow pattern, etc..
文摘OBJECTIVE Ginsenoside Rg3 (Rg3) has shown anti-tumor effects on various tumor cells. It has been widely used in China for non-small cell lung cancer (NSCLC). However, there are only a few clinical trials to study the effectiveness of Rg3 on NSCLC, and almost them are small- samples, so we performed a meta-analysis on the results of the studies we collected in order to investigate the effectiveness of Rg3 on NSCLC. METHODS A meta-analysis was conducted in all the selected randomized controlled trials evaluating the effectiveness of Rg3 on NSCLC patients. All on-line databases regarding Rg3 from 1950 to 2011 were searched. Supplemental hand searching of the references of retrieved articles was performed. RESULTS Six trials met the inclusion criteria. Four of them compared chemotherapy plus Rg3 with chemotherapy alone, and the other 2 compared chemotherapy plus Rg3 with chemotherapy plus placebo. These trials are homogeneous. Two of the trials report overall survival, but the data are not suitable for a meta-analysis. After meta-analysis was conducted in the included studies comparing the effects of chemotherapy plus Rg3 with that of chemotherapy alone or chemotherapy plus placebo, it was suggested that chemotherapy plus Rg3 increased the response rate [odds ratio: 2.64 (95% Ch 1.70-4.11), fixed effects model] and disease control rate [odds ratio: 3.34 (95% CI: 1.92-5.81); fixed effects model] of the patients at stage II-IV, especially for the patients at stage Ill-IV. CONCLUSION Meta-analysis of the available evidence suggests that Rg3 plus chemotherapy improves the response rate of NSCLC patients, and well-designed RCTs with large sample size are needed.
文摘The primary aim of clinical trials is to investigate whether a treatment is effective for a particular disease or condition. Randomized controlled clinical trials are considered to be the gold standard for evaluating the effect of a certain intervention. However, in clinical trials, even after randomization, there are situations where the patients differ substantially with respect to the baseline value of the outcome variable. Many a times the response to interventions depends on the baseline values of the outcome variable. When there are baseline-dependent treatment effects, differences among treatments vary as a function of baseline level. Although variation in outcome associated with baseline value is accounted for in ANCOVA, analysis of individual differences in treatment effect is precluded by the homogeneity of regression assumption. This assumption requires that expected differences in outcome among treatments be constant across all baseline levels. To overcome this difficulty, Weigel and Narvaez [7] proposed a regression model for two treatment groups to analyze individual response to treatments in randomized controlled clinical trials. The authors reviewed the model suggested by Weigel and Narvaez and extended further for three or more treatment groups. The utility of the model was demonstrated with real life data from a randomized controlled clinical trial of bronchial asthma.
文摘Objective: The efficacy of preoperative transarterial chemoembolization(TACE) for hepatectomy on hepatocelluar carcinoma(HCC) is still controversial. This study aims to evaluate the efficacy of preoperative TACE on resectable HCC. Methods: Pubmed, SCI, Medline, EMBASE, Cochrane Datebase, CNKI were searched. The articles that focused on preoperative TACE for resectable HCC, published from 1990 to 2012, were collected by computerized search of literatures and manual search of bibliographies. The relevant clinical trials' data were reviewed by meta-analysis using the random effects model or fixed effect model by heterogeneity. The outcomes were expressed as odds ratio(OR) with 95% confidence intervals(CIs). Results: A total of 1347 patients were included in these 7 studies, the cases were divided into the preoperative TACE group and the non-preoperative TACE group, and there was no difference between the two groups in the 3-year disease-free survival rate, with an odds ratio of 1.14(95% CI = 0.90–1.45, P = 0.27); the 5-year disease-free survival rate in the preoperative TACE group was better than that in the non-TACE group with an odds ratio of 1.35(95% CI = 1.07–1.74, P = 0.02); the 5-year overall survival rate in the preoperative TACE group was higher than that in the non-TACE group with an odds ratio of 0.59(95% CI = 0.46–0.77, P < 0.0001). Conclusion: The present data suggests that preoperative TACE has no different in improving the 3-year disease-free survival rate with non-TACE group for resectable HCC, while it can improve the 5-year disease-free survival rate and the 5-year overall survival rate. More randomized controlled trials using large sample size are needed to provide sufficient evidence to confirm current conclusion.
文摘Objective: The aim of this study was to compare the efficacy in alleviating the endotracheal tube related discomfort and the safetyof intracufflidocaine (in different forms) with air and/or normal saline (NS) during general anesthesia with tracheal intubation. Methods: Cochrane Central Register of Controlled Trials, PubMed and Embase were searched for relevant studies. Thirteen randomized, controlled trials involving 1 010 patients were ultimately identified. A meta-analysis of all randomized controlled trials fulfilling the predefined criteria was performed. Random-effect model and subgroup studies were used when significant heterogeneity existed among those trials. Results: Compared with air and NS, intracufflidocaine could significantly alleviate the severity of sore throat at different time points (15min, 30min, lh, 2h, 3h, 6h, 12h and 24h aiter extubation) and the occurrence of cough, restlessness, postoperative nausea and vomiting, dysphonia and hoarseness. Besides intracufflidocaine brought about a significant prolongation of spontaneous ventilation time. It was worth mentioning that, compared withlidocaine or its hydrochloride form, alkalinized lidocainewas much more efficient in reducing the severity of sore throat and prolonging spontaneous ventilation time. Conclusion: The present meta-analysis indicates that intracuttlidocaine can significantly improve endotracheal tube tolerance and this improvement can be strengthened by alkalinization of lidocaine.