符合“能源之星”固态照明要求的离线高功率因数TRIAC调光LED驱动器参考设计

本文介绍了对固态照明的规范要求,给出了满足这些要求的离线式高功率因数TRIAC调光LED驱动器参考设计方案,以及该方案的测试结果。     

A multi-year composite of GVI data as a clear reflectance database

A method is developed to generate a top of the atmosphere clear reflectance from the Global Vegetation Index (GVI) product. Our goal is to use this dataset as a threshold to be applied to the forthcoming POLDER observations, for operational cloud detection. The method is based on the hypothesis that clouds add a high frequency signal to the slow variations of the surface reflectance in clear conditions. The validity of our algorithm is verified through an analysis of the temporal profile of the reflectance that it generates. We show that these profiles are better than those resulting from the simpler Maximum Value Composite (MVC) method. The method is applied to five years of GVI products and the results are used to derive a reference database which accounts for the interannual variability of the surface reflectance.     

SH1 domain autophosphorylation of P210 BCR/ABL is required for transformation but not growth factor independence

P210 BCR/ABL is a chimeric oncogene implicated in the pathogenesis of chronic myelogenous leukemia. BCR sequences have been shown to be required for activation of the tyrosine kinase and transforming functions of BCR/ABL. In this work, we show that two other structural requirements for full transforming activity of P210 BCR/ABL include a functional tyrosine kinase and the presence of tyrosine 1294, a site of autophosphorylation within the tyrosine kinase domain. Replacement of tyrosine 1294 with phenylalanine (1294F) greatly diminishes the transforming activity of BCR/ABL without affecting the specific activity of the protein tyrosine kinase. Expression of an exogenous myc gene in fibroblasts partially complements the transforming capacity of mutant P210 BCR/ABL (1294F). Surprisingly, tyrosine 1294 is not required for efficient induction of growth factor-independence in hematopoietic cell lines by P210 BCR/ABL. These results suggest that autophosphorylation at tyrosine 1294 may be important for recognition and phosphorylation of cellular substrates in the pathway of transformation, but it is not critical for mediating the events which lead to growth factor independence.     

Diagnosis-related groups: a comparative analysis of hospital activity in different countries

Comparative study of hospital activities in the Novgorod district and nine countries of the European Community, carried out within the framework of the International Project CAMISE (Case Mix and Severity) of the European Community on the basis of the classification system for diagnosis-related groups, showed a lower Case Mix Index, a longer hospital stay for all major disease, and a lower surgical activity in the hospitals of the Novgorod district in comparison with other European countries. The detected differences are largely due to specific features in the organization of hospital service in Russia (no special hospitals for acute and chronic patients, no nursing homes) and insufficiently intensive therapeutic and diagnostic process.     

DNA fingerprinting of the lizard Lacerta dahli: isolation of a genomic polymorphism of mini- and microsatellite loci

We performed a lateral approach for the release of post-traumatic stiffness of the elbow in 22 patients using a modified technique designed to spare the lateral ligaments. They were reviewed after a mean interval of 26 months. The total humeroulnar joint movement had increased from a mean of 74 degrees to 129 degrees and forearm rotation from a mean of 135 degrees to 159 degrees. Both pain and function in the elbow had improved significantly. This modified lateral approach allows release of post-traumatic contracture without disruption of the lateral collateral ligament or the origins of the extensor tendon at the lateral epicondyle of the humerus. The advantages include a simplified surgical procedure, less operative morbidity, and unrestricted rehabilitation.     

Lack of association of higher insulin levels with diffuse atherosclerotic coronary artery disease in nondiabetics

Since there is experimental evidence that insulin promotes atherosclerosis, we tested the hypothesis that insulin levels are higher in patients with diffuse atherosclerotic coronary artery disease by measuring insulin levels in 46 nondiabetic patients with angiographically defined diffuse coronary artery disease and 46 normal controls with angiographically normal coronary arteries. Fasting insulin levels were similar in both groups of patients: 7.70 +/- 5.77 microU/mL in those with diffuse coronary disease versus 7.39 +/- 5.01 microU/mL in controls. Also, insulin levels drawn 1 and 2 h after oral glucose challenge were not significantly different in patients with diffuse disease (48.78 +/- 32.46 microU/mL and 42.26 +/- 32.38 microU/mL, respectively) compared with patients with normal coronary arteries (51.03 +/- 28.01 microU/mL and 43.79 +/- 31.62 microU/mL, respectively). We conclude that insulin probably does not promote clinical atherosclerosis in nondiabetics.     

Denaturation Kinetics of Myofibrillar Proteins in Bovine Muscle

Differential scanning calorimetry was used to monitor the thermal denaturation kinetics of myofibrillar proteins in bovine muscle at pH 5.6. The activation energy, pre-exponential factor, rate constant and mean life time for each transition were calculated by means of a dynamic method. The kinetic values and the proposed reaction order (n= 1) were confirmed applying an isothermal method as a test. The position of the endothermal peaks proved to be pH dependent. Evidences suggest that peak III is a result of actin denaturation and possibly other thin filament proteins. Peaks I and II would represent the thermal transition of thick filaments. The number of bonds involved in each transition were estimated.