Increasing the wear resistance of reworked parts of transport engines

The article describes new mixed technology for increasing the wear resistance of parts of transport engines based on the example of a crankshaft. The basis of the new mixed technology is the heat treatment of crankshaft pins and the application of a multilayer antifriction coating in one technological cycle. Laboratory tests on mixed technology application revealed an increase of wear resistance of crankshaft pins, a reduction in the coefficient of friction, a reduction in the running-in period, and an increase in the scoring resistance and operating life of the crankshaft.     

The functional activity of anti-endotoxin factors in viral hepatitis A and B

Bacterial endotoxins (BE) that are lipopolysaccharide complexes (LPS) are a structural component of the external membrane of gram-negative bacteria. In normalcy, BE interact with many types of cells in the mammals. In terms of the concentration, BE may cause cell damage or stimulate the production of many biological mediators, such as interleukins, prostaglandinds, alpha-TNF. Many gastrointestinal bacteria in humans are gram-negative and BE constantly enter the blood. In health, the absence of a toxic response to BE is explained by the presence of natural humoral and cellular antiendotoxic systems and the hepatic absorption of LPS. In patients with hepatitis A and B, the following indices of the blood antiendotoxic systems were determined: the level of antiendotoxic antibodies to Re-chemotype glycolipids was assessed by the passive hemagglutination reaction in the "Antiendotox-1-test"; the count of polymorphonuclear leukocyte (PMNL) fixating LPS on their own surface and endotoxin binding function of PMNL was in vitro measured by the strain ELISA and sandwich ELISA with Re-glycolipids, respectively (LPS-test); the endotoxin fixation function of serum high density lipoproteins (HDL) was also assessed. The humoral and cellular antiendotoxic systems in patients with mild advanced hepatitis A and B was studied when the disease was most clinically significant, at an early convalescence, and at convalescence itself. Finally, the findings indicate that there is a significant decrease in Re-antibody levels and there is a greater absorption ability of HDL than that in the control. Six different types of an antiendotoxic fixation reaction of PMNL were identified in patients with viral hepatitis in the different periods of the disease. The alterations observed may play an important role in the pathogenesis of toxemia in patients with viral hepatitis.     

The comparative study of peroxidase activity and substrate binding properties of cytochrome P450 2B4 incorporated into phospholipid vesicles with the use of two different methods

The comparative study of peroxidase activities and substrate binding properties of cytochrome p450 2B4 in reconstituted vesicles prepared with the use of two different techniques, and microsomal cytochrome P450 was carried out. The data obtained show that the two types of cytochrome P450 2B4-containing proteoliposomes do not differ substantially from each other with respect to H2O2- or cumene hydroperoxide-dependent substrate hydroxylation activities as well as substrate binding properties of hemoprotein reconstituted. However, some parameters measured with proteoliposomal cytochrome P450 are markedly different from those measured with microsomal hemoprotein, suggesting the existence of conformational differences between the molecules of these two cytochromes or the differences in the depth of their immersion into lipid bilayer.     

基于新标准的俄罗斯釆金业职业风险评估

当前俄罗斯正在进行立法改革以实现治理体系现代化，其中改革的重点是国家管理体系中的劳动保护、工业安全和突发事件的应急处理。过去的立法体系侧重于对受伤员工提供健康补偿和医疗救护，而新的立法体系则以预防为主，以期通过建立完善的风险管理机制和运行规则，提高安全生产水平、普及安全文化教育，保障员工的生命安全。新标准强调企业必须进行职业风险评估，并将职业风险评估纳入企业工作管理体系。论文以采金业为例，选取伊尔库茨克州波戴波区金矿露天采场为研究案例，探讨了现代化职业风险评估的方法，明确了职业风险评估首先要进行危害鉴别，编制了风险源管理档案清单。采用实测员工风险因素的“记分法”和数学模拟“矩阵法”完成了伊尔库茨克州波戴波区金矿露天采场主要职业的风险评估。研究表明: 在钻井爆破作业场所，由碎石的喷射、粉尘的排放和噪声效应引起的危险为不可接受风险，通过实施安全生产制度（即遵守安全标准和技术要求、为工人提供防护装备）,可将高风险和不可接受风险化解为可接受风险；阐述了高风险职业，编制了风险手册，提出了改善工作条件的首要措施是消除影响爆破手和钻机操作员的有害因素，并为员工提供能更有效预防噪音和振动的个人防护用品。