Since the roll damping of ships has significant effects of viscosity, it is difficult to calculate it theoretically. Therefore, experimental results or some prediction methods are used to get the roll damping in desig...Since the roll damping of ships has significant effects of viscosity, it is difficult to calculate it theoretically. Therefore, experimental results or some prediction methods are used to get the roll damping in design stage of ships. Among some prediction methods, Ikeda＇s one is widely used in many ship motion computer programs. Using the method, the roll damping of various ship hulls with various bilge keels can be calculated to investigate its characteristics. To calculate the roll damping of each ship, detailed data of the ship are needed to input. Therefore, a simpler prediction method is expected in primary design stage. Such a simple method must be useful to validate the results obtained by a computer code to predict it on the basis of Ikeda＇s method, too. On the basis of the predicted roll damping by Ikeda＇s method for various ships, a very simple prediction formula of the roll damping of ships is deduced in the present paper. Ship hull forms are systematically changed by changing length, beam, draft, mid-ship sectional coefficient and prismatic coefficient. It is found, however, that this simple formula can not be used for ships that have high position of the center of gravity. A modified method to improve accuracy for such ships is proposed.展开更多
AIM:To predict treatment success using only simple clinical data from peg-interferon plus ribavirin therapy for chronic hepatitis C. METHODS:We analyzed the clinical data of 176 patients with chronic hepatitis and hep...AIM:To predict treatment success using only simple clinical data from peg-interferon plus ribavirin therapy for chronic hepatitis C. METHODS:We analyzed the clinical data of 176 patients with chronic hepatitis and hepatitis C virus genotype 1 who received 48 wk standard therapy, derived a predictive formula to assess a sustained virological response of the individual patient using a logistic regression model and confirmed the validity of this formula.The formula was constructed using data from the first 100 patients enrolled and validated using data from the remaining 76 patients. RESULTS:Sustained virological response was obtained in 83(47.2%)of the patients and we derived formulae to predict sustained virological response at pretreatment and weeks 4,12 and 24.The likelihood of sustained virological response could be predicted effectively bythe formulae at weeks 4,12 and 24(the area under the curve of the receiver operating characteristic:0.821, 0.802,and 0.891,respectively),but not at baseline (0.570).The formula at week 48 was also constructed and validation by test data achieved good prediction with 0.871 of the area under the curve of the receiver operating characteristic.Prediction by this formula was always superior to that by viral kinetics. CONCLUSION:These results suggested that our formula combined with viral kinetics provides a clear direction of therapy for each patient and enables the best tailored treatment.展开更多
Thin-walled torispherical heads under internal pressure can fail by plastic buckling because of compressive circumferential stresses in the head knuckle.However,existing formulas still have limitations,such as complic...Thin-walled torispherical heads under internal pressure can fail by plastic buckling because of compressive circumferential stresses in the head knuckle.However,existing formulas still have limitations,such as complicated expressions and low accuracy,in determining buckling pressure.In this paper,we propose a new formula for calculating the buckling pressure of torispherical heads based on elastic-plastic analysis and experimental results.First,a finite element(FE)method based on the arc-length method is established to calculate the plastic buckling pressure of torispherical heads,considering the effects of material strain hardening and geometrical nonlinearity.The buckling pressure results calculated by the FE method in this paper have good consistency with those of BOSOR5,which is a program for calculating the elastic-plastic bifurcation buckling pressure based on the finite difference energy method.Second,the effects of geometric parameters,material parameters,and restraint form of head edge on buckling pressure are investigated.Third,a new formula for calculating plastic buckling pressure is developed by fitting the curve of FE results and introducing a reduction factor determined from experimental data.Finally,based on the experimental results,we compare the predictions of the new formula with those of existing formulas.It is shown that the new formula has a higher accuracy than the existing ones.展开更多
The ability to identify patients with risk of mortality in the initial stages allows us to introduce a more aggressive treatment in order to improve patients’ survival. In this study, we used systemic inflammatory re...The ability to identify patients with risk of mortality in the initial stages allows us to introduce a more aggressive treatment in order to improve patients’ survival. In this study, we used systemic inflammatory response syndrome (SIRS) criteria, respiratory and heart rate per minute, and consciousness level [(Glasgow coma scale (GCS)] to develop a formula to predict death in patients admitted to the Infectious Diseases ward of Imam Reza hospital. Methods: This descriptive study was a cross sectional study done in the Infectious Diseases ward of Imam Reza hospital, Mashhad University of Medical Sciences, Iran. Alive and dead patients between the dates September 1, 2006 to September 1, 2007 were studied. In this study, data such as past medical history, prescribed drugs and their administration by nursing and medical staff was extracted from patients’ files. Also, the time of death, the first vital signs recorded in the hospital and the formula H = (PR + RR) - GCS (respiratory rate per minute plus heart rate per minute minus Glasgow coma scale (GCS)) was calculated for both alive and dead patients. Data was analyzed by SPSS software. Mann-Whitney test, Roc Curve, and logistic regression model were used for data analysis. Results: The total number of admitted patients was 1007 of whom 90 (10.82%) died. One patient was excluded from the study. Out of 90 dead patients, 51 (56.6%) were male and 39 (43.3%) were female. There was no significant difference between the two groups regarding the gender (P > 0.05). The mean age of the study group (deceased) was 59 ± 21 and the mean age of the control group (alive) was 58 ± 21. The Mann-Whitney test showed that the result of H Formula was significantly different between the two groups, (126 ± 26 for the study group and 111 ± 22 for the control group). The cutoff for H Formula was equal to 112.5. Negative and positive predictive values, specificity and sensitivity were 0.85, 0.35, 0.57, and 0.70 respectively. Logistic regression results show that the H index contents independently affected the mortality of infected patients. Conclusion: With regard to the importance of measuring vital signs in diagnosis and determining the mortality in patients with infectious disease, the H (Heydari) formula can be valuable for evaluation and determination of mortality risk and consequently, early intervention. Patients with severe tachycardia, severe tachypnea and altered mental status that cannot be properly and quickly improved within 2 hours after admission via hydration and other measures are at higher risk of mortality.展开更多
目的探究人偏肺病毒感染的发病机制,并基于逆向网络药理学思维对其进行中药组方预测。方法于Genecards数据库和OMIM数据库中获取人偏肺病毒的靶点,将所得靶点导入STRING数据库构建蛋白互作网络,利用Cytoscape 3.9.0软件结合R软件获得关...目的探究人偏肺病毒感染的发病机制,并基于逆向网络药理学思维对其进行中药组方预测。方法于Genecards数据库和OMIM数据库中获取人偏肺病毒的靶点,将所得靶点导入STRING数据库构建蛋白互作网络,利用Cytoscape 3.9.0软件结合R软件获得关键靶点。根据GO和KEGG富集分析明确其发病机制与通路。根据度值选取核心靶点,通过Uniprot数据库将核心靶点转换后于traditional Chinese medicine SP数据库逆向收集中药成分及中药。使用Cytoscape 3.9.0软件构建关键靶点-有效成分-中药网络关系图。利用STBYL-2.0软件将核心靶点与核心成分进行分子对接验证,最后确定度值较高中药并分析整理其性、味、归经。结果共获取人偏肺病毒靶点209个,根据度值得到26个关键靶点。GO富集分析主要得出1866个条目,KEGG富集分析显示88条信号通路。根据度值选取的8个核心靶点于traditional Chinese medicine SP数据库中共匹配到29种入血成分及298种中药。将8个核心靶点蛋白与度值较高的4种核心成分进行分子对接验证,结果稳定且良好。整理度值≥10的中药共69种,主要为苦参、连翘、余甘子、半枝莲、木蝴蝶、银杏叶等,以寒性药、苦味药居多,其次为温性药、辛味药,并且肝、肺二经居多。结论运用逆向网络药理学思维及分子对接技术对人偏肺病毒进行靶点、通路、成分和中药预测,为临床治疗及研究提供新思路和理论依据。展开更多
The multi-spring shear mechanism plastic model in this paper is defined in strain space to simulate pore pressure generation and development in sands under cyclic loading and undrained conditions, and the rotation of ...The multi-spring shear mechanism plastic model in this paper is defined in strain space to simulate pore pressure generation and development in sands under cyclic loading and undrained conditions, and the rotation of principal stresses can also be simulated by the model with cyclic behavior of anisotropic consolidated sands. Seismic residual deformations of typical caisson quay walls under different engineering situations are analyzed in detail by the plastic model, and then an index of liquefaction extent is applied to describe the regularity of seismic residual deformation of caisson quay wall top under different engineering situations. Some correlated prediction formulas are derived from the results of regression analysis between seismic residual deformation of quay wall top and extent of liquefaction in the relative safety backfill sand site. Finally, the rationality and the reliability of the prediction methods are validated by test results of a 120 g-centrifuge shaking table, and the comparisons show that some reliable seismic residual deformation of caisson quay can be predicted by appropriate prediction formulas and appropriate index of liquefaction extent.展开更多
A simple formula to predict the received global solar irradiance q(t), W/m2 for clear days is suggested on pure theoretical basis. It is expressed in terms of the length of the local day time td which is well defined ...A simple formula to predict the received global solar irradiance q(t), W/m2 for clear days is suggested on pure theoretical basis. It is expressed in terms of the length of the local day time td which is well defined in literatures on meteorological basis. The introduced distribution is also a function of the maximum value of the daily received irradiance qmax. which in turn is expressed in term of the solar constant. This renders the trial to be a closed system. Thus the obtained distribution is not a semi empirical one. Both cases of symmetrical and asymmetrical distributions for q(t) are considered. For its simplicity it can be easily integrated along the length of the day to get the daily totals of solar energy received by unit horizontal area. This is important for practical applications. Comparison between computed according to the present model and published experimental meteorological data in Barcelona (Spain), Hong Kong (China), Jeddah and Makkah (Saudi Arabia) is given as illustrative examples. Better fitting relative to the published trials for the same locations are obtained. The introduced model itself gives good fitting for the intermediate intervals points of the local day time which is the more effective region. The estimated relative error is 12% for Hong Kong, and it is 7% for Barcelona, Jeddah and Makah.展开更多
Based on the measurement mechanism of mobility in pressure measurement while drilling, through analyzing a large number of mobility data, it is found that under the condition of water-based mud drilling, the product o...Based on the measurement mechanism of mobility in pressure measurement while drilling, through analyzing a large number of mobility data, it is found that under the condition of water-based mud drilling, the product of mobility from pressure measurement while drilling and the viscosity of mud filtrate is infinitely close to the water phase permeability under the residual oil in relative permeability experiment. Based on this, a method converting the mobility from pressure measurement while drilling to core permeability is proposed, and the permeability based on Timur formula has been established. Application of this method in Penglai 19-9 oilfield of Bohai Sea shows:(1) Compared with the permeability calculated by the model of adjacent oilfields, the permeability calculated by this model is more consistent with the permeability calculated by core analysis.(2) Based on the new model, the correlation between the calculated mobility of well logging and the actual drilling specific productivity index bas been established. Compared with the relationship established by using the permeability model of an adjacent oilfield, the correlation of the new model is better.(3) Productivity of four directional wells was predicted, and the prediction results are in good agreement with the actual production after drilling.展开更多
文摘Since the roll damping of ships has significant effects of viscosity, it is difficult to calculate it theoretically. Therefore, experimental results or some prediction methods are used to get the roll damping in design stage of ships. Among some prediction methods, Ikeda＇s one is widely used in many ship motion computer programs. Using the method, the roll damping of various ship hulls with various bilge keels can be calculated to investigate its characteristics. To calculate the roll damping of each ship, detailed data of the ship are needed to input. Therefore, a simpler prediction method is expected in primary design stage. Such a simple method must be useful to validate the results obtained by a computer code to predict it on the basis of Ikeda＇s method, too. On the basis of the predicted roll damping by Ikeda＇s method for various ships, a very simple prediction formula of the roll damping of ships is deduced in the present paper. Ship hull forms are systematically changed by changing length, beam, draft, mid-ship sectional coefficient and prismatic coefficient. It is found, however, that this simple formula can not be used for ships that have high position of the center of gravity. A modified method to improve accuracy for such ships is proposed.
文摘AIM:To predict treatment success using only simple clinical data from peg-interferon plus ribavirin therapy for chronic hepatitis C. METHODS:We analyzed the clinical data of 176 patients with chronic hepatitis and hepatitis C virus genotype 1 who received 48 wk standard therapy, derived a predictive formula to assess a sustained virological response of the individual patient using a logistic regression model and confirmed the validity of this formula.The formula was constructed using data from the first 100 patients enrolled and validated using data from the remaining 76 patients. RESULTS:Sustained virological response was obtained in 83(47.2%)of the patients and we derived formulae to predict sustained virological response at pretreatment and weeks 4,12 and 24.The likelihood of sustained virological response could be predicted effectively bythe formulae at weeks 4,12 and 24(the area under the curve of the receiver operating characteristic:0.821, 0.802,and 0.891,respectively),but not at baseline (0.570).The formula at week 48 was also constructed and validation by test data achieved good prediction with 0.871 of the area under the curve of the receiver operating characteristic.Prediction by this formula was always superior to that by viral kinetics. CONCLUSION:These results suggested that our formula combined with viral kinetics provides a clear direction of therapy for each patient and enables the best tailored treatment.
基金supported by the National Natural Science Foundation of China(No.52105161).
文摘Thin-walled torispherical heads under internal pressure can fail by plastic buckling because of compressive circumferential stresses in the head knuckle.However,existing formulas still have limitations,such as complicated expressions and low accuracy,in determining buckling pressure.In this paper,we propose a new formula for calculating the buckling pressure of torispherical heads based on elastic-plastic analysis and experimental results.First,a finite element(FE)method based on the arc-length method is established to calculate the plastic buckling pressure of torispherical heads,considering the effects of material strain hardening and geometrical nonlinearity.The buckling pressure results calculated by the FE method in this paper have good consistency with those of BOSOR5,which is a program for calculating the elastic-plastic bifurcation buckling pressure based on the finite difference energy method.Second,the effects of geometric parameters,material parameters,and restraint form of head edge on buckling pressure are investigated.Third,a new formula for calculating plastic buckling pressure is developed by fitting the curve of FE results and introducing a reduction factor determined from experimental data.Finally,based on the experimental results,we compare the predictions of the new formula with those of existing formulas.It is shown that the new formula has a higher accuracy than the existing ones.
文摘The ability to identify patients with risk of mortality in the initial stages allows us to introduce a more aggressive treatment in order to improve patients’ survival. In this study, we used systemic inflammatory response syndrome (SIRS) criteria, respiratory and heart rate per minute, and consciousness level [(Glasgow coma scale (GCS)] to develop a formula to predict death in patients admitted to the Infectious Diseases ward of Imam Reza hospital. Methods: This descriptive study was a cross sectional study done in the Infectious Diseases ward of Imam Reza hospital, Mashhad University of Medical Sciences, Iran. Alive and dead patients between the dates September 1, 2006 to September 1, 2007 were studied. In this study, data such as past medical history, prescribed drugs and their administration by nursing and medical staff was extracted from patients’ files. Also, the time of death, the first vital signs recorded in the hospital and the formula H = (PR + RR) - GCS (respiratory rate per minute plus heart rate per minute minus Glasgow coma scale (GCS)) was calculated for both alive and dead patients. Data was analyzed by SPSS software. Mann-Whitney test, Roc Curve, and logistic regression model were used for data analysis. Results: The total number of admitted patients was 1007 of whom 90 (10.82%) died. One patient was excluded from the study. Out of 90 dead patients, 51 (56.6%) were male and 39 (43.3%) were female. There was no significant difference between the two groups regarding the gender (P > 0.05). The mean age of the study group (deceased) was 59 ± 21 and the mean age of the control group (alive) was 58 ± 21. The Mann-Whitney test showed that the result of H Formula was significantly different between the two groups, (126 ± 26 for the study group and 111 ± 22 for the control group). The cutoff for H Formula was equal to 112.5. Negative and positive predictive values, specificity and sensitivity were 0.85, 0.35, 0.57, and 0.70 respectively. Logistic regression results show that the H index contents independently affected the mortality of infected patients. Conclusion: With regard to the importance of measuring vital signs in diagnosis and determining the mortality in patients with infectious disease, the H (Heydari) formula can be valuable for evaluation and determination of mortality risk and consequently, early intervention. Patients with severe tachycardia, severe tachypnea and altered mental status that cannot be properly and quickly improved within 2 hours after admission via hydration and other measures are at higher risk of mortality.
文摘目的探究人偏肺病毒感染的发病机制,并基于逆向网络药理学思维对其进行中药组方预测。方法于Genecards数据库和OMIM数据库中获取人偏肺病毒的靶点,将所得靶点导入STRING数据库构建蛋白互作网络,利用Cytoscape 3.9.0软件结合R软件获得关键靶点。根据GO和KEGG富集分析明确其发病机制与通路。根据度值选取核心靶点,通过Uniprot数据库将核心靶点转换后于traditional Chinese medicine SP数据库逆向收集中药成分及中药。使用Cytoscape 3.9.0软件构建关键靶点-有效成分-中药网络关系图。利用STBYL-2.0软件将核心靶点与核心成分进行分子对接验证,最后确定度值较高中药并分析整理其性、味、归经。结果共获取人偏肺病毒靶点209个,根据度值得到26个关键靶点。GO富集分析主要得出1866个条目,KEGG富集分析显示88条信号通路。根据度值选取的8个核心靶点于traditional Chinese medicine SP数据库中共匹配到29种入血成分及298种中药。将8个核心靶点蛋白与度值较高的4种核心成分进行分子对接验证,结果稳定且良好。整理度值≥10的中药共69种,主要为苦参、连翘、余甘子、半枝莲、木蝴蝶、银杏叶等,以寒性药、苦味药居多,其次为温性药、辛味药,并且肝、肺二经居多。结论运用逆向网络药理学思维及分子对接技术对人偏肺病毒进行靶点、通路、成分和中药预测,为临床治疗及研究提供新思路和理论依据。
基金supported by the Research Foundation of Jiangsu University of Science and Technology for Introducing Talents(Grant No. 35280901)
文摘The multi-spring shear mechanism plastic model in this paper is defined in strain space to simulate pore pressure generation and development in sands under cyclic loading and undrained conditions, and the rotation of principal stresses can also be simulated by the model with cyclic behavior of anisotropic consolidated sands. Seismic residual deformations of typical caisson quay walls under different engineering situations are analyzed in detail by the plastic model, and then an index of liquefaction extent is applied to describe the regularity of seismic residual deformation of caisson quay wall top under different engineering situations. Some correlated prediction formulas are derived from the results of regression analysis between seismic residual deformation of quay wall top and extent of liquefaction in the relative safety backfill sand site. Finally, the rationality and the reliability of the prediction methods are validated by test results of a 120 g-centrifuge shaking table, and the comparisons show that some reliable seismic residual deformation of caisson quay can be predicted by appropriate prediction formulas and appropriate index of liquefaction extent.
文摘A simple formula to predict the received global solar irradiance q(t), W/m2 for clear days is suggested on pure theoretical basis. It is expressed in terms of the length of the local day time td which is well defined in literatures on meteorological basis. The introduced distribution is also a function of the maximum value of the daily received irradiance qmax. which in turn is expressed in term of the solar constant. This renders the trial to be a closed system. Thus the obtained distribution is not a semi empirical one. Both cases of symmetrical and asymmetrical distributions for q(t) are considered. For its simplicity it can be easily integrated along the length of the day to get the daily totals of solar energy received by unit horizontal area. This is important for practical applications. Comparison between computed according to the present model and published experimental meteorological data in Barcelona (Spain), Hong Kong (China), Jeddah and Makkah (Saudi Arabia) is given as illustrative examples. Better fitting relative to the published trials for the same locations are obtained. The introduced model itself gives good fitting for the intermediate intervals points of the local day time which is the more effective region. The estimated relative error is 12% for Hong Kong, and it is 7% for Barcelona, Jeddah and Makah.
基金Supported by the China National Science and Technology Major Project(2016ZX058-001)the CNOOC Scientific and Technological Project(CNOOC-KJ135-ZDXM36-TJ).
文摘Based on the measurement mechanism of mobility in pressure measurement while drilling, through analyzing a large number of mobility data, it is found that under the condition of water-based mud drilling, the product of mobility from pressure measurement while drilling and the viscosity of mud filtrate is infinitely close to the water phase permeability under the residual oil in relative permeability experiment. Based on this, a method converting the mobility from pressure measurement while drilling to core permeability is proposed, and the permeability based on Timur formula has been established. Application of this method in Penglai 19-9 oilfield of Bohai Sea shows:(1) Compared with the permeability calculated by the model of adjacent oilfields, the permeability calculated by this model is more consistent with the permeability calculated by core analysis.(2) Based on the new model, the correlation between the calculated mobility of well logging and the actual drilling specific productivity index bas been established. Compared with the relationship established by using the permeability model of an adjacent oilfield, the correlation of the new model is better.(3) Productivity of four directional wells was predicted, and the prediction results are in good agreement with the actual production after drilling.
