AIM To investigate the prognostic value of preoperative fbri-nogen concentration （FIB） and D-dimer-fibrinogen ratio （DFR） in gastrointestinal stromal tumors （GISTs）.METHODS The purpose of this study was to retro...AIM To investigate the prognostic value of preoperative fbri-nogen concentration （FIB） and D-dimer-fibrinogen ratio （DFR） in gastrointestinal stromal tumors （GISTs）.METHODS The purpose of this study was to retrospectively ana-lyze 170 patients with GISTs who were admitted to our hospital from January 2010 to December 2015. The op-timal cutoff values of related parameters were estimated by receiver operating characteristic （ROC） curve analysis. The recurrence free survival （RFS） rate was evaluated using Kaplan-Meier curves. Univariate analysis and multivariate Cox regression models were used to analyze the prognostic factors of GISTs. The relationship between the FIB, D-dimer, DFR, platelet count （PLT）, and the clinicopathological features of GISTs was described by the chi-square test or nonparametric rank sum test （Mann-Whitney test）.RESULTS In ROC analysis, the optimal cutoff values of FIB, D-dimer, DFR, and PLT were 3.24 g/L, 1.24 mg/L, 0.354, and 197.5 （× 109/L）, respectively. Univariate analysis and the Kaplan-Meier survival curve showed that FIB, D-dimer, DFR, PLT,National Institutes of Health （NIH） risk category, tumor size, tumor location, and mitotic index were signifcantly relevant to the 3-year and 5-year survival rate of patients （ P 〈 0.05）. Cox multivariate regression analysis illustrated that FIB （RR： 0.108, 95%CI： 0.031-0.373）, DFR （RR： 0.319, 95%CI： 0.131-0.777）, and NIH risk category （ RR： 0.166, 95%CI： 0.047-0.589） were independent prognostic factors of the RFS rate （ P 〈 0. 05）. Moreover, FIB, D-dimer, DFR, and PLT were correlated with the clinical features of GISTs.CONCLUSIONFIB, D-dimer, DFR, and PLT are all related to the prognosis of GISTs. Moreover, FIB and DFR may be independent risk factors for predicting the prognosis of resectable GISTs.展开更多
It is of importance to study and predict the possible buckling of submarine pipeline under thermal stress in pipeline design.Since soil resistance is not strong enough to restrain the large deformation of pipeline,hig...It is of importance to study and predict the possible buckling of submarine pipeline under thermal stress in pipeline design.Since soil resistance is not strong enough to restrain the large deformation of pipeline,high-order buckling modes occur very easily.Analytical solutions to high-order buckling modes were obtained in this paper.The relationships between buckling temperature and the amplitude or the wavelength of buckling modes were established.Analytical solutions were obtained to predict the occurrence and consequence of in-service buckling of a heated pipeline in an oil field.The effects of temperature difference and properties of subsoil on buckling modes were investigated.The results show that buckling will occur once temperature difference exceeds safe temperature;high-order pipeline buckling occurs very easily;the larger the friction coefficients are,the safer the submarine pipeline will be.展开更多
AIM： To identify clinical parameters, and develop an Upper Gastrointesinal Bleeding （UGIB） Etiology Score for predicting the types of UGIB and validate the score. METHODS： Patients with UGIB who underwent endoscop...AIM： To identify clinical parameters, and develop an Upper Gastrointesinal Bleeding （UGIB） Etiology Score for predicting the types of UGIB and validate the score. METHODS： Patients with UGIB who underwent endoscopy within 72 h were enrolled. Clinical and basic laboratory parameters were prospectively collected. Predictive factors for the types of UGIB were identified by univariate and multivariate analyses and were used to generate the UGIB Etiology Score. The best cutoff of the score was defined from the receiver operating curve and prospectively validated in another set of patients with UGIB. RESULTS： Among 261 patients with UGIB, 47 （18%） had variceal and 214 （82%） had non-variceal bleeding. Univariate analysis identified 27 distinct parameters significantly associated with the types of UGIB. Logistic regression analysis identified only 3 independent factors for predicting variceal bleeding; previous diagnosis of cirrhosis or signs of chronic liver disease （OR 22.4, 95% CI 8.3-60.4, P 〈 0.001）, red vomitus （OR 4.6, 95% CI 1.8-11.9, P = 0.02）, and red nasogastric （NG） aspirate （OR 3.3, 95% CI 1.3-8.3, P = 0.011）. The UGIB Etiology Score was calculated from （3.1× previous diagnosis of cirrhosis or signs of chronic liver disease） ＋ （1.5× red vomitus） ＋ （1.2× red NG aspirate）, when 1 and 0 are used for the presence and absence of each factor, respectively. Using a cutoff ≥ 3.1, the sensitivity, specificity, accuracy, positive predictive value （PPV）, and negative predictive value （NPV） in predicting variceal bleeding were 85%, 81%, 82%, 50%, and 96%, respectively. The score was prospectively validated in cases （46 variceal and 149 another set of 195 UGIB non-variceal bleeding）. The PPV and NPV of a score ≥ 3.1 for variceal bleeding were 79% and 97%, respectively. CONCLUSION： The UGIB Etiology Score, composed of 3 parameters, using a cutoff ≥ 3.1 accurately predicted variceal bleeding and may help to guide the choice of initial therapy for UGIB before endoscopy.展开更多
This paper presents a novel bootstrap based method for Receiver Operating Characteristic (ROC) analysis of Fisher classifier. By defining Fisher classifier’s output as a statistic, the bootstrap technique is used to ...This paper presents a novel bootstrap based method for Receiver Operating Characteristic (ROC) analysis of Fisher classifier. By defining Fisher classifier’s output as a statistic, the bootstrap technique is used to obtain the sampling distributions of the outputs for the positive class and the negative class respectively. As a result, the ROC curve is a plot of all the (False Positive Rate (FPR), True Positive Rate (TPR)) pairs by varying the decision threshold over the whole range of the boot- strap sampling distributions. The advantage of this method is, the bootstrap based ROC curves are much stable than those of the holdout or cross-validation, indicating a more stable ROC analysis of Fisher classifier. Experiments on five data sets publicly available demonstrate the effectiveness of the proposed method.展开更多
Parallel manipulator systems as promising precision devices are used widely in current researches. A novel large workspace flexure parallel manipulator system utilizing wide-range flexure hinges as passive joints is p...Parallel manipulator systems as promising precision devices are used widely in current researches. A novel large workspace flexure parallel manipulator system utilizing wide-range flexure hinges as passive joints is proposed in this paper, which can attain sub-micron-seale precision over the cubic centimeter motion range. This paper introduces the mechanical system architecture based on the wide-range flexure hinges, analyzes the kinematics via stiffness matrices, presents the control system configuration and control strategy, and finally gives the system performance test results.展开更多
Debussy is one of the famous composers in music history, and he not only created a lot of innovative music, but also created a musical impressionist era, it is a landmark composers having. ＂Fireworks＂ is one of the ...Debussy is one of the famous composers in music history, and he not only created a lot of innovative music, but also created a musical impressionist era, it is a landmark composers having. ＂Fireworks＂ is one of the important works of Debussy, which was the last song he composed 24 piano preludes, and this work fully reflects all his creative ideas, creative approach and creative style, as well as their patriotism inner world monologue. This paper focuses on the piano Debussy＇ s 24 Preludes a brief introduction, analyze the reasons for the formation of its style and structure of the work through, music image, sound system and playing tips and other aspects of ＂fireworks＂ .展开更多
文摘AIM To investigate the prognostic value of preoperative fbri-nogen concentration （FIB） and D-dimer-fibrinogen ratio （DFR） in gastrointestinal stromal tumors （GISTs）.METHODS The purpose of this study was to retrospectively ana-lyze 170 patients with GISTs who were admitted to our hospital from January 2010 to December 2015. The op-timal cutoff values of related parameters were estimated by receiver operating characteristic （ROC） curve analysis. The recurrence free survival （RFS） rate was evaluated using Kaplan-Meier curves. Univariate analysis and multivariate Cox regression models were used to analyze the prognostic factors of GISTs. The relationship between the FIB, D-dimer, DFR, platelet count （PLT）, and the clinicopathological features of GISTs was described by the chi-square test or nonparametric rank sum test （Mann-Whitney test）.RESULTS In ROC analysis, the optimal cutoff values of FIB, D-dimer, DFR, and PLT were 3.24 g/L, 1.24 mg/L, 0.354, and 197.5 （× 109/L）, respectively. Univariate analysis and the Kaplan-Meier survival curve showed that FIB, D-dimer, DFR, PLT,National Institutes of Health （NIH） risk category, tumor size, tumor location, and mitotic index were signifcantly relevant to the 3-year and 5-year survival rate of patients （ P 〈 0.05）. Cox multivariate regression analysis illustrated that FIB （RR： 0.108, 95%CI： 0.031-0.373）, DFR （RR： 0.319, 95%CI： 0.131-0.777）, and NIH risk category （ RR： 0.166, 95%CI： 0.047-0.589） were independent prognostic factors of the RFS rate （ P 〈 0. 05）. Moreover, FIB, D-dimer, DFR, and PLT were correlated with the clinical features of GISTs.CONCLUSIONFIB, D-dimer, DFR, and PLT are all related to the prognosis of GISTs. Moreover, FIB and DFR may be independent risk factors for predicting the prognosis of resectable GISTs.
基金Supported by Innovative Research Groups of the National Natural Science Foundation of China(No.51021004)National Natural Science Foundation of China(No.40776055)+1 种基金Program for New Century Excellent Talents in University(NCET-11-0370)State Key Laboratory of Ocean Engineering Foundation(1002)
文摘It is of importance to study and predict the possible buckling of submarine pipeline under thermal stress in pipeline design.Since soil resistance is not strong enough to restrain the large deformation of pipeline,high-order buckling modes occur very easily.Analytical solutions to high-order buckling modes were obtained in this paper.The relationships between buckling temperature and the amplitude or the wavelength of buckling modes were established.Analytical solutions were obtained to predict the occurrence and consequence of in-service buckling of a heated pipeline in an oil field.The effects of temperature difference and properties of subsoil on buckling modes were investigated.The results show that buckling will occur once temperature difference exceeds safe temperature;high-order pipeline buckling occurs very easily;the larger the friction coefficients are,the safer the submarine pipeline will be.
文摘AIM： To identify clinical parameters, and develop an Upper Gastrointesinal Bleeding （UGIB） Etiology Score for predicting the types of UGIB and validate the score. METHODS： Patients with UGIB who underwent endoscopy within 72 h were enrolled. Clinical and basic laboratory parameters were prospectively collected. Predictive factors for the types of UGIB were identified by univariate and multivariate analyses and were used to generate the UGIB Etiology Score. The best cutoff of the score was defined from the receiver operating curve and prospectively validated in another set of patients with UGIB. RESULTS： Among 261 patients with UGIB, 47 （18%） had variceal and 214 （82%） had non-variceal bleeding. Univariate analysis identified 27 distinct parameters significantly associated with the types of UGIB. Logistic regression analysis identified only 3 independent factors for predicting variceal bleeding; previous diagnosis of cirrhosis or signs of chronic liver disease （OR 22.4, 95% CI 8.3-60.4, P 〈 0.001）, red vomitus （OR 4.6, 95% CI 1.8-11.9, P = 0.02）, and red nasogastric （NG） aspirate （OR 3.3, 95% CI 1.3-8.3, P = 0.011）. The UGIB Etiology Score was calculated from （3.1× previous diagnosis of cirrhosis or signs of chronic liver disease） ＋ （1.5× red vomitus） ＋ （1.2× red NG aspirate）, when 1 and 0 are used for the presence and absence of each factor, respectively. Using a cutoff ≥ 3.1, the sensitivity, specificity, accuracy, positive predictive value （PPV）, and negative predictive value （NPV） in predicting variceal bleeding were 85%, 81%, 82%, 50%, and 96%, respectively. The score was prospectively validated in cases （46 variceal and 149 another set of 195 UGIB non-variceal bleeding）. The PPV and NPV of a score ≥ 3.1 for variceal bleeding were 79% and 97%, respectively. CONCLUSION： The UGIB Etiology Score, composed of 3 parameters, using a cutoff ≥ 3.1 accurately predicted variceal bleeding and may help to guide the choice of initial therapy for UGIB before endoscopy.
基金the Natural Science Foundation of Zhejiang Province of China (No. Y104540)the Foundation of the Key Laboratory of Advanced Information Science and Network Technology of Beijing, China (No.TDXX0509).
文摘This paper presents a novel bootstrap based method for Receiver Operating Characteristic (ROC) analysis of Fisher classifier. By defining Fisher classifier’s output as a statistic, the bootstrap technique is used to obtain the sampling distributions of the outputs for the positive class and the negative class respectively. As a result, the ROC curve is a plot of all the (False Positive Rate (FPR), True Positive Rate (TPR)) pairs by varying the decision threshold over the whole range of the boot- strap sampling distributions. The advantage of this method is, the bootstrap based ROC curves are much stable than those of the holdout or cross-validation, indicating a more stable ROC analysis of Fisher classifier. Experiments on five data sets publicly available demonstrate the effectiveness of the proposed method.
文摘Parallel manipulator systems as promising precision devices are used widely in current researches. A novel large workspace flexure parallel manipulator system utilizing wide-range flexure hinges as passive joints is proposed in this paper, which can attain sub-micron-seale precision over the cubic centimeter motion range. This paper introduces the mechanical system architecture based on the wide-range flexure hinges, analyzes the kinematics via stiffness matrices, presents the control system configuration and control strategy, and finally gives the system performance test results.
文摘Debussy is one of the famous composers in music history, and he not only created a lot of innovative music, but also created a musical impressionist era, it is a landmark composers having. ＂Fireworks＂ is one of the important works of Debussy, which was the last song he composed 24 piano preludes, and this work fully reflects all his creative ideas, creative approach and creative style, as well as their patriotism inner world monologue. This paper focuses on the piano Debussy＇ s 24 Preludes a brief introduction, analyze the reasons for the formation of its style and structure of the work through, music image, sound system and playing tips and other aspects of ＂fireworks＂ .
