The technology of continuously welded rails (CWRs) is important in modern railway track structures. To measure rail stress, resistance strain gauges are preferred due to their good stability, sensitivity, and esist...The technology of continuously welded rails (CWRs) is important in modern railway track structures. To measure rail stress, resistance strain gauges are preferred due to their good stability, sensitivity, and esistance to external interference. Based on the bi-directional strain method, we present a new method for measuring longitudinal rail stress using resistance strain gauges and develop a monitoring device for rail stress to realize long-term and multi-point measurement. Also relevant experimental verification and analysis are conducted. Results indicate that under various constraints the rail stress–strain values can be calculated just with the measured total longitudinal strain and total vertical strain. Considering the measurement error caused by sectional feature of sensors, we put forward a correction equation applicable to different stress conditions. Although the temperature values of the four full-bridge stress gauges can offset each other, the measurement error caused by rail flexural strain can also be eliminated to a certain extent at the same time, the nonuniform distribution of rail cross section temperature and unbalanced flexural strain still affect the measurement error. The experimental results also show that the developed rail-stress-monitoring sensor is suitable for measuring rail stress with reliable working performance.展开更多
Background:Bariatric surgery represents an important treatment option for severely obese patients with nonalcoholic fatty liver disease(NAFLD).However,there remains inadequate data regarding the effects of different b...Background:Bariatric surgery represents an important treatment option for severely obese patients with nonalcoholic fatty liver disease(NAFLD).However,there remains inadequate data regarding the effects of different bariatric procedures on various NAFLD parameters,especially for histological outcomes.Thus,this meta-analysis aimed to compare the effects of restrictive bariatric procedures and foregut bypass on the metabolic,biochemical,and histological parameters for patients with NAFLD.Methods:Medline and Embase were searched for articles relating to bariatric procedures and NAFLD.Pairwise meta-analysis was conducted to compare efficacy of bariatric procedures pre-vs.post-procedure with subgroup analysis to further compare restrictive against foregut bypass procedures.Results:Thirty-one articles involving 3,355 patients who underwent restrictive bariatric procedures(n=1,460)and foregut bypass(n=1,895)were included.Both foregut bypass(P<0.01)and restrictive procedures(P=0.03)significantly increased odds of fibrosis resolution.Compared to restrictive procedures,foregut bypass resulted in a borderline non-significant decrease in fibrosis score(P=0.06)and significantly lower steatosis score(P<0.001).For metabolic parameters,foregut bypass significantly lowered body mass index(P=0.003)and low-density lipoprotein(P=0.008)compared to restrictive procedures.No significant differences were observed between both procedures for aspartate aminotransferase(P=0.17)and alkaline phosphatase(P=0.61).However,foregut bypass resulted in significantly lower gamma-glutamyl transferase than restrictive procedures(P=0.01)while restrictive procedures resulted in significantly lower alanine transaminase than foregut bypass(P=0.02).Conclusions:The significant histological and metabolic advantages and comparable improvements in biochemical outcomes support the choice of foregut bypass over restrictive bariatric procedures in NAFLD management.展开更多
Background and Aims:Pharmaceutical therapy for NASH is associated with lipid modulation,but the consensus on drug treatment is limited and lacks comparative analysis of effectiveness.A network meta-analysis was conduc...Background and Aims:Pharmaceutical therapy for NASH is associated with lipid modulation,but the consensus on drug treatment is limited and lacks comparative analysis of effectiveness.A network meta-analysis was conducted to compare NASH drug classes in lipid modulation.Methods:Online databases were searched for randomized controlled trails(RCTs)evaluating NASH treatments in biopsy-proven NASH patients.Treatments were classified into four groups:(1)inflammation,(2)energy,(3)bile acids,and(4)fibro-sis based on the mechanism of action.A Bayesian network analysis was conducted with outcome measured by mean difference(MD)with credible intervals(Crl)and surface un-der the cumulative ranking curve(SUCRA).Results:Forty-four RCTs were included in the analysis.Bile acid modulat-ing treatments(MD:0.05,Crl:0.03-0.07)were the best treatment for improvement in high-density lipid(HDL)cho-lesterol,followed by treatments modulating energy(MD:0.03,Crl:0.02-0.04)and fibrosis(MD:0.01,Crl:−0.12 to 0.14)compared with placebo.The top three treatments for reduction in triglycerides were treatments modulating energy(MD:−0.46,Crl:−0.49 to−0.43),bile acids(MD:−0.22,Crl:−0.35 to−0.09),and inflammation(MD:−0.08,Crl:−0.13 to−0.03)compared with placebo.SUCRA found treatment modulating fibrosis(MD:−1.27,Crl:−1.76 to−0.79)was the best treatment for reduction in low-density lipid(LDL)cholesterol followed by treatment modulating in-flammation(MD:−1.03,Crl:−1.09 to−0.97)and energy(MD:−0.37,Crl:−0.39 to−0.34)compared with placebo,but LDL cholesterol was worsened by treatments modulat-ing bile acids.Conclusions:Network analysis comparing the class effects of dyslipidemia modulation in NASH found that treatment targets can include optimization of athero-genic dyslipidemia.Future studies are required to evaluate the cardiovascular outcomes.展开更多
基金the fund support by the National Natural Science Foundation of China (No. 51425804, No. U1234201 and No. U1334203)
文摘The technology of continuously welded rails (CWRs) is important in modern railway track structures. To measure rail stress, resistance strain gauges are preferred due to their good stability, sensitivity, and esistance to external interference. Based on the bi-directional strain method, we present a new method for measuring longitudinal rail stress using resistance strain gauges and develop a monitoring device for rail stress to realize long-term and multi-point measurement. Also relevant experimental verification and analysis are conducted. Results indicate that under various constraints the rail stress–strain values can be calculated just with the measured total longitudinal strain and total vertical strain. Considering the measurement error caused by sectional feature of sensors, we put forward a correction equation applicable to different stress conditions. Although the temperature values of the four full-bridge stress gauges can offset each other, the measurement error caused by rail flexural strain can also be eliminated to a certain extent at the same time, the nonuniform distribution of rail cross section temperature and unbalanced flexural strain still affect the measurement error. The experimental results also show that the developed rail-stress-monitoring sensor is suitable for measuring rail stress with reliable working performance.
文摘Background:Bariatric surgery represents an important treatment option for severely obese patients with nonalcoholic fatty liver disease(NAFLD).However,there remains inadequate data regarding the effects of different bariatric procedures on various NAFLD parameters,especially for histological outcomes.Thus,this meta-analysis aimed to compare the effects of restrictive bariatric procedures and foregut bypass on the metabolic,biochemical,and histological parameters for patients with NAFLD.Methods:Medline and Embase were searched for articles relating to bariatric procedures and NAFLD.Pairwise meta-analysis was conducted to compare efficacy of bariatric procedures pre-vs.post-procedure with subgroup analysis to further compare restrictive against foregut bypass procedures.Results:Thirty-one articles involving 3,355 patients who underwent restrictive bariatric procedures(n=1,460)and foregut bypass(n=1,895)were included.Both foregut bypass(P<0.01)and restrictive procedures(P=0.03)significantly increased odds of fibrosis resolution.Compared to restrictive procedures,foregut bypass resulted in a borderline non-significant decrease in fibrosis score(P=0.06)and significantly lower steatosis score(P<0.001).For metabolic parameters,foregut bypass significantly lowered body mass index(P=0.003)and low-density lipoprotein(P=0.008)compared to restrictive procedures.No significant differences were observed between both procedures for aspartate aminotransferase(P=0.17)and alkaline phosphatase(P=0.61).However,foregut bypass resulted in significantly lower gamma-glutamyl transferase than restrictive procedures(P=0.01)while restrictive procedures resulted in significantly lower alanine transaminase than foregut bypass(P=0.02).Conclusions:The significant histological and metabolic advantages and comparable improvements in biochemical outcomes support the choice of foregut bypass over restrictive bariatric procedures in NAFLD management.
文摘Background and Aims:Pharmaceutical therapy for NASH is associated with lipid modulation,but the consensus on drug treatment is limited and lacks comparative analysis of effectiveness.A network meta-analysis was conducted to compare NASH drug classes in lipid modulation.Methods:Online databases were searched for randomized controlled trails(RCTs)evaluating NASH treatments in biopsy-proven NASH patients.Treatments were classified into four groups:(1)inflammation,(2)energy,(3)bile acids,and(4)fibro-sis based on the mechanism of action.A Bayesian network analysis was conducted with outcome measured by mean difference(MD)with credible intervals(Crl)and surface un-der the cumulative ranking curve(SUCRA).Results:Forty-four RCTs were included in the analysis.Bile acid modulat-ing treatments(MD:0.05,Crl:0.03-0.07)were the best treatment for improvement in high-density lipid(HDL)cho-lesterol,followed by treatments modulating energy(MD:0.03,Crl:0.02-0.04)and fibrosis(MD:0.01,Crl:−0.12 to 0.14)compared with placebo.The top three treatments for reduction in triglycerides were treatments modulating energy(MD:−0.46,Crl:−0.49 to−0.43),bile acids(MD:−0.22,Crl:−0.35 to−0.09),and inflammation(MD:−0.08,Crl:−0.13 to−0.03)compared with placebo.SUCRA found treatment modulating fibrosis(MD:−1.27,Crl:−1.76 to−0.79)was the best treatment for reduction in low-density lipid(LDL)cholesterol followed by treatment modulating in-flammation(MD:−1.03,Crl:−1.09 to−0.97)and energy(MD:−0.37,Crl:−0.39 to−0.34)compared with placebo,but LDL cholesterol was worsened by treatments modulat-ing bile acids.Conclusions:Network analysis comparing the class effects of dyslipidemia modulation in NASH found that treatment targets can include optimization of athero-genic dyslipidemia.Future studies are required to evaluate the cardiovascular outcomes.