Growth of stand average DBH is discussed bassed on relationship between standgrowth and stand density.Growth equation of stand average DBH is fitted with data of 65 plotsand 130 stem analyses of site index 18 meter of...Growth of stand average DBH is discussed bassed on relationship between standgrowth and stand density.Growth equation of stand average DBH is fitted with data of 65 plotsand 130 stem analyses of site index 18 meter of old-growth Larch(Larix gmeliniiRupr.)collectedin Great Xing’an Mountain m Inner Monglia.Variable-density yield tables of old—growth Larchare constructed based on growth equation of stand average DBH and relationship between standaverage DBH and the other stand attributes.展开更多
The relatively long scan time is still a bottleneck for both clinical applications and research of magnetic resonance imaging. To reduce the data acquisition time, we propose a novel fast magnetic resonance imaging me...The relatively long scan time is still a bottleneck for both clinical applications and research of magnetic resonance imaging. To reduce the data acquisition time, we propose a novel fast magnetic resonance imaging method based on parallel variable-density spiral acquisition, which combines undersampling optimization and nonlocal total variation reconstruction. The undersampling optimization promotes the incoherence of resultant aliasing artifact via the "worst-case" residual error metric, and thus accelerates the data acquisition. Moreover, nonlocal total variation reconstruction is utilized to remove such an incoherent aliasing artifact and so improve image quality. The feasibility of the proposed method is demonstrated by both numerical phantom simulation and in vivo experiment. The experimental results show that the proposed method can achieve high acceleration factor and effectively remove an aliasing artifact from data undersampling with well-preserved image details. The image quality is better than that achieved with the total variation method.展开更多
AIM:To investigate the diagnostic accuracy of the mean platelet volume and platelet distribution width in acute appendicitis.METHODS:This retrospective,case-controlled study compared 295 patients with acute appendicit...AIM:To investigate the diagnostic accuracy of the mean platelet volume and platelet distribution width in acute appendicitis.METHODS:This retrospective,case-controlled study compared 295 patients with acute appendicitis(Group?Ⅰ),100 patients with other intra-abdominal infections(GroupⅡ),and 100 healthy individuals(GroupⅢ)between January 2012 and January 2013.The age,gender,and white blood cell count,neutrophil percentage,mean platelet volume,and platelet distribution width values from blood samples were compared among the groups.Statistical analyses were performed using SPSS for Windows 21.0 software.In addition,the sensitivity,specificity,positive and negative predictive values and likelihood ratios,and diagnostic accuracy were calculated.RESULTS:The mean ages of patients were 29.9±12.0years for Group?Ⅰ,31.5±14.0 years for GroupⅡ,and30.4±13.0 years for GroupⅢ.Demographic features such as age and gender were not significantly different among the groups.White blood cell count,neutrophil percentage and platelet distribution width were significantly higher in Group?Ⅰ?compared to groupsⅡandⅢ(P<0.05).Diagnostically,the sensitivity,specificity and diagnostic accuracy were 73.1%,94.0%,and 78%for white blood cell count,70.0%,96.0%,and 76.0%for neutrophil percentage,29.5%,49.0%,and 34.0%for mean platelet volume,and 97.1%,93.0%,and 96.0%for platelet distribution width,respectively.The highest diagnostic accuracy detected was for platelet distribution width between Group?Ⅰ?and GroupⅢ(P<0.01).CONCLUSION:Platelet distribution width analysis can be used for diagnosis of acute appendicitis without requiring additional tests,thus reducing the cost and loss of time.展开更多
文摘Growth of stand average DBH is discussed bassed on relationship between standgrowth and stand density.Growth equation of stand average DBH is fitted with data of 65 plotsand 130 stem analyses of site index 18 meter of old-growth Larch(Larix gmeliniiRupr.)collectedin Great Xing’an Mountain m Inner Monglia.Variable-density yield tables of old—growth Larchare constructed based on growth equation of stand average DBH and relationship between standaverage DBH and the other stand attributes.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.81101030 and 61271132)
文摘The relatively long scan time is still a bottleneck for both clinical applications and research of magnetic resonance imaging. To reduce the data acquisition time, we propose a novel fast magnetic resonance imaging method based on parallel variable-density spiral acquisition, which combines undersampling optimization and nonlocal total variation reconstruction. The undersampling optimization promotes the incoherence of resultant aliasing artifact via the "worst-case" residual error metric, and thus accelerates the data acquisition. Moreover, nonlocal total variation reconstruction is utilized to remove such an incoherent aliasing artifact and so improve image quality. The feasibility of the proposed method is demonstrated by both numerical phantom simulation and in vivo experiment. The experimental results show that the proposed method can achieve high acceleration factor and effectively remove an aliasing artifact from data undersampling with well-preserved image details. The image quality is better than that achieved with the total variation method.
文摘AIM:To investigate the diagnostic accuracy of the mean platelet volume and platelet distribution width in acute appendicitis.METHODS:This retrospective,case-controlled study compared 295 patients with acute appendicitis(Group?Ⅰ),100 patients with other intra-abdominal infections(GroupⅡ),and 100 healthy individuals(GroupⅢ)between January 2012 and January 2013.The age,gender,and white blood cell count,neutrophil percentage,mean platelet volume,and platelet distribution width values from blood samples were compared among the groups.Statistical analyses were performed using SPSS for Windows 21.0 software.In addition,the sensitivity,specificity,positive and negative predictive values and likelihood ratios,and diagnostic accuracy were calculated.RESULTS:The mean ages of patients were 29.9±12.0years for Group?Ⅰ,31.5±14.0 years for GroupⅡ,and30.4±13.0 years for GroupⅢ.Demographic features such as age and gender were not significantly different among the groups.White blood cell count,neutrophil percentage and platelet distribution width were significantly higher in Group?Ⅰ?compared to groupsⅡandⅢ(P<0.05).Diagnostically,the sensitivity,specificity and diagnostic accuracy were 73.1%,94.0%,and 78%for white blood cell count,70.0%,96.0%,and 76.0%for neutrophil percentage,29.5%,49.0%,and 34.0%for mean platelet volume,and 97.1%,93.0%,and 96.0%for platelet distribution width,respectively.The highest diagnostic accuracy detected was for platelet distribution width between Group?Ⅰ?and GroupⅢ(P<0.01).CONCLUSION:Platelet distribution width analysis can be used for diagnosis of acute appendicitis without requiring additional tests,thus reducing the cost and loss of time.