Nonalcoholic fatty liver disease(NAFLD),defined by excessive liver fat deposition related to the metabolic syndrome,is a leading cause of progressive liver disease,for which accurate non-invasive staging systems and e...Nonalcoholic fatty liver disease(NAFLD),defined by excessive liver fat deposition related to the metabolic syndrome,is a leading cause of progressive liver disease,for which accurate non-invasive staging systems and effective treatments are still lacking.Evidence has shown that increased ferritin levels are associated with the metabolic insulin resistance syndrome,and higher hepatic iron and fat content.Hyperferritinemia and iron stores have been associated with the severity of liver damage in NAFLD,and iron depletion reduced insulin resistance and liver enzymes.Recently,Kowdley et al demonstrated in a multicenter study in 628 adult patients with NAFLD from the NAFLD-clinical research network database with central re-evaluation of liver histology and iron staining that the increased serum ferritin level is an independent predictor of liver damage in patients with NAFLD,and is useful to identify NAFLD patients at risk of non-alcoholic steatohepatitis and advanced fibrosis.These data indicate that incorporation of serum ferritin level may improve the performance of noninvasive scoring of liver damage in patients with NAFLD,and that iron depletion still represents an attractive therapeutic target to prevent the progression of liver damage in these patients.展开更多
There are two fundamental goals in statistical learning： identifying relevant predictors and ensuring high prediction accuracy. The first goal, by means of variable selection, is of particular importance when the tru...There are two fundamental goals in statistical learning： identifying relevant predictors and ensuring high prediction accuracy. The first goal, by means of variable selection, is of particular importance when the true underlying model has a sparse representation. Discovering relevant predictors can enhance the performance of the prediction for the fitted model. Usually an estimate is considered desirable if it is consistent in terms of both coefficient estimate and variable selection. Hence, before we try to estimate the regression coefficients β , it is preferable that we have a set of useful predictors m hand. The emphasis of our task in this paper is to propose a method, in the aim of identifying relevant predictors to ensure screening consistency in variable selection. The primary interest is on Orthogonal Matching Pursuit（OMP）.展开更多
Objective： To assess the correlation between five anthropometric parameters and the distance from tibial tuberosity to medial malleolus in 100 volunteers. Methods： Six anthropometric parameters were measured in 50 m...Objective： To assess the correlation between five anthropometric parameters and the distance from tibial tuberosity to medial malleolus in 100 volunteers. Methods： Six anthropometric parameters were measured in 50 male and 50 female medical students using a metallic scale： medial knee joint line to ankle joint line （K-A）, medial knee joint line to medial malleolus （K-MM）, tibial tuberosity to ankle joint （TT-A）, tibial tuberosity to medial malleolus （TT- MM）, olecranon to 5th metacarpal head （O-MH） and body height （BH）. Nail size predicted based upon Tr-MM measurement was chosen as ideal nail size. A constant was derived for each of the six anthropometric parameters which was either added or subtracted to each measurement to derive nail size. A regression equation was applied to BH measurements. Nail sizes calculated were compared with that obtained from TI＇-MM measurement and accuracy was evaluated. Accuracy of O-MH and BH regression equations recommended by other authors were calculated in our data. Results： Adding 11 mm to Tr-A distance had highest accuracy （81%） and correlation （0.966） in predicting nails correctly. Subtracting 33 mm from K-MM measurement and 25 mm from K-A distance derived accurate sizes in 69% and 76% respectively. Adding 6 mm to O-MH distance had a poor accuracy of 51%. Nail size prediction based upon body height regression equation derived correct nail sizes in only 34% of the cases. Regression equation analysis by other authors based on O-MH and BH distances yielded correct sizes in 11% and 5% of the cases respectively. Conclusion： TT-A, K-A and K-MM measurements can be used simultaneously to increase accuracy of nail size prediction. This method would be helpful in determining nail size preoperatively especially when one anatomic landmark is difficult to palpate.展开更多
For a general second-order variable coefficient elliptic boundary value problem in three dimensions, the authors derive the weak estimate of the first type for tensor-product linear pentahedral finite elements. In add...For a general second-order variable coefficient elliptic boundary value problem in three dimensions, the authors derive the weak estimate of the first type for tensor-product linear pentahedral finite elements. In addition, the estimate for the W1,1-seminorm of the discrete derivative Green＇s function is given. Finally, the authors show that the derivatives of the finite element solution uh and the corresponding interpolant Hu are superclose in the pointwise sense of the L∞-norm.展开更多
基金Supported by First Università degli Studi di Milano 2007,2008,to Valenti L and Fargion SRicerca corrente Ospedale Maggiore Policlinico 2006 and 2008,to Valenti L and FargionSCentro per lo Studio delle Malattie del Fegato e del Metabolismo
文摘Nonalcoholic fatty liver disease(NAFLD),defined by excessive liver fat deposition related to the metabolic syndrome,is a leading cause of progressive liver disease,for which accurate non-invasive staging systems and effective treatments are still lacking.Evidence has shown that increased ferritin levels are associated with the metabolic insulin resistance syndrome,and higher hepatic iron and fat content.Hyperferritinemia and iron stores have been associated with the severity of liver damage in NAFLD,and iron depletion reduced insulin resistance and liver enzymes.Recently,Kowdley et al demonstrated in a multicenter study in 628 adult patients with NAFLD from the NAFLD-clinical research network database with central re-evaluation of liver histology and iron staining that the increased serum ferritin level is an independent predictor of liver damage in patients with NAFLD,and is useful to identify NAFLD patients at risk of non-alcoholic steatohepatitis and advanced fibrosis.These data indicate that incorporation of serum ferritin level may improve the performance of noninvasive scoring of liver damage in patients with NAFLD,and that iron depletion still represents an attractive therapeutic target to prevent the progression of liver damage in these patients.
文摘There are two fundamental goals in statistical learning： identifying relevant predictors and ensuring high prediction accuracy. The first goal, by means of variable selection, is of particular importance when the true underlying model has a sparse representation. Discovering relevant predictors can enhance the performance of the prediction for the fitted model. Usually an estimate is considered desirable if it is consistent in terms of both coefficient estimate and variable selection. Hence, before we try to estimate the regression coefficients β , it is preferable that we have a set of useful predictors m hand. The emphasis of our task in this paper is to propose a method, in the aim of identifying relevant predictors to ensure screening consistency in variable selection. The primary interest is on Orthogonal Matching Pursuit（OMP）.
文摘Objective： To assess the correlation between five anthropometric parameters and the distance from tibial tuberosity to medial malleolus in 100 volunteers. Methods： Six anthropometric parameters were measured in 50 male and 50 female medical students using a metallic scale： medial knee joint line to ankle joint line （K-A）, medial knee joint line to medial malleolus （K-MM）, tibial tuberosity to ankle joint （TT-A）, tibial tuberosity to medial malleolus （TT- MM）, olecranon to 5th metacarpal head （O-MH） and body height （BH）. Nail size predicted based upon Tr-MM measurement was chosen as ideal nail size. A constant was derived for each of the six anthropometric parameters which was either added or subtracted to each measurement to derive nail size. A regression equation was applied to BH measurements. Nail sizes calculated were compared with that obtained from TI＇-MM measurement and accuracy was evaluated. Accuracy of O-MH and BH regression equations recommended by other authors were calculated in our data. Results： Adding 11 mm to Tr-A distance had highest accuracy （81%） and correlation （0.966） in predicting nails correctly. Subtracting 33 mm from K-MM measurement and 25 mm from K-A distance derived accurate sizes in 69% and 76% respectively. Adding 6 mm to O-MH distance had a poor accuracy of 51%. Nail size prediction based upon body height regression equation derived correct nail sizes in only 34% of the cases. Regression equation analysis by other authors based on O-MH and BH distances yielded correct sizes in 11% and 5% of the cases respectively. Conclusion： TT-A, K-A and K-MM measurements can be used simultaneously to increase accuracy of nail size prediction. This method would be helpful in determining nail size preoperatively especially when one anatomic landmark is difficult to palpate.
基金supported by the Natural Science Foundation of Zhejiang Province under Grant No.Y6090131the Natural Science Foundation of Ningbo City under Grant No.2010A610101
文摘For a general second-order variable coefficient elliptic boundary value problem in three dimensions, the authors derive the weak estimate of the first type for tensor-product linear pentahedral finite elements. In addition, the estimate for the W1,1-seminorm of the discrete derivative Green＇s function is given. Finally, the authors show that the derivatives of the finite element solution uh and the corresponding interpolant Hu are superclose in the pointwise sense of the L∞-norm.
