Radionuclides in the Kara sea bottom sediments

The contents and distribution of natural (214Pb, 214Bi, 228Ac, and 208Tl) and technogenic (90Sr, 137Cs, and 60Co) radionuclides in the Kara Sea bottom sediments was analyzed by using the materials collected by R/V "Pomor" (Murmansk Marine Biological Institute). In 1994, no high (critical) concentrations of technogenic radioisotopes were found in the sea sediments, while the spots (regions) of elevated 137Cs content found in 1984 were not confirmed in 1994. It was proposed that the main sources of entry of technogenic radionuclides in the sea sediments in the last years are the flow of the Ob'-Yenisei waters and container burials of radioactive waste in the sea, which appeared to have been markedly corroded. The latter is confirmed by detection in some places of 60Co, which was not previously found in the sediments.     

THE THROMBORESISTANCE OF A HEPARIN-POLYVINYL ALCOHOL HYDROGEL†

Heparin immobilized onto polyvinyl alcohol (PVA) by action of glutaraldehyde has been shown to be biologically active in a novel parallel flow arteriovenous shunt in dogs. The hepann-PVA hydrogel originally devised by Merrill and his collaborators was applied as a coaling to chromic acid etched polyethylene lubing. A pair of Y-connectors was used to divert < 2% of the flow in the AV shunt through the heparinized tube, which remained patent for longer Ihan two hours while a control tube without heparin was occluded within 30 minutes at a main shunt flow rate of ～l50mL/min. This enhanced patency was achieved without significant release from the surface, consistent with earlier experiments attributing the thromboresistance of the heparin-PVA hydrogel to the formation of a surface bound inactive thrombin-antithrombin III complex. Radiolabelled thrombin adsorbed onto beads made from the gel was readily displaced by arvinized plasma, indicating that the inactive complex was not itself permanently bound to the surface.

These results demonstrate the utility of Merrill's hydrogel for preparing materials with potential long lerm thromboresistance and for testing the validity of the hypothesized limitations to the long term use of immobilized heparin.     

IP电话：创新者的追求

早在１９９５年就有人预测Ｉｎｔｅｒｎｅｔ在某种意义上可能会对电话技术产生重要影响。短短几年间,ＩＰ电话技术的屡次重大突破为这一预言提供了不可辨驳的佐证,也使人们不再小看这一事物。目前,ＩＰ电话供应商已开发出大量应用：ＩＰ增强型服务、因特网呼叫等待／电话倍频器、基于ＩＰ的ＰＢＸ和基于Ｗｅｂ的呼叫中心等,ＩＰ电话正逐步改变着这个世界的交流方式。     

ERP软件流程模型的分析与构建

从研究企业物流和资金流中物对象和资金对象的特点入手，指出企业内有三种类型的物对象，但不是所有物对象都可以被同时准确定位、定型和定价值，管理上只关注仓库里的物；通过分析物与资金两流关联的因素及方法，指出理论上只有三个因素影响集成，这三个关联因素可以将物流和资金流“实时”集成。借鉴SAP的移动类型和评估类型的，可以使实现更加实用，模型更加合理；给出了一个集成的ERP软件的简化流程模型，并根据该模型分析了物流和资金流信息集成对企业管理及组织结构的影响，指出了两流不集成在管理上的缺陷。     

Lyme disease in Mato Grosso do Sul State, Brazil: report of three clinical cases, including the first of Lyme meningitis in Brazil

The authors report the occurrence of the first three clinical cases of Lyme disease in Mato Grosso do Sul State, including the first case of Lyme meningitis in Brazil. These were identified by clinical and laboratorial criteria. Anti-Borrelia burgdorferi antibody search was carried out through ELISA and Western Blotting techniques, the former providing identification of IgG class antibodies alone, in one only of those cases. Through Immunoblotting, the following features were found in serum: 5 IgG and 2 IgM bands for the first case; 7 IgG and 2 IgM bands for the second; and 5 IgG and 6 IgM bands for the third. In the latter, presence fo specific antibodies was searched in liquor, due to lymphomonocitary meningitis occurrence, and one IgM band was detected. After antibiotic therapy, all patients exhibited significant clinical and laboratorial improvement in their conditions along with symptom regression to the present moment.     

Moderate folate depletion increases plasma homocysteine and decreases lymphocyte DNA methylation in postmenopausal women

To determine the human folate requirement on the basis of changes in biochemical pathways, we studied the effect of controlled folate intakes on plasma homocysteine and lymphocyte DNA methylation and deoxynucleotide content in healthy postmenopausal women. Eight women (49-63 y of age) were housed in a metabolic unit and fed a low folate diet containing 56 microg/d of folate for 91 d. Folate intake was varied by supplementing 55-460 microg/d of folic acid (pteroylglutamic acid) to the diet to provide total folate intake periods of 5 wk at 56 microg/d, 4 wk at 111 microg/d and 3 wk at 286-516 microg/d. A subclinical folate deficiency with decreased plasma folate was created during the first two periods. This resulted in significantly elevated plasma homocysteine and urinary malondialdehyde, and lymphocyte DNA hypomethylation. The folate depletion also resulted in an increased ratio of dUTP/dTTP in mitogen-stimulated lymphocyte DNA and decreased lymphocyte NAD, changes suggesting misincorporation of uracil into DNA and increased DNA repair activity. The DNA hypomethylation was reversed with 286-516 microg/d of folate repletion, whereas the elevated homocysteine decreased with 516 but not 286 microg/d of folate. The results indicate that marginal folate deficiency may alter DNA composition and that the current RDA of 180 microg/d may not be sufficient to maintain low plasma homocysteine concentrations of some postmenopausal women.     

HIV-associated brain pathology: a comparative international study

OBJECTIVES: This study examined the use of aides in occupational therapy practice, the supervision and training of aides, and practitioners' attitudes toward the use of aides. METHOD: A questionnaire was mailed to a systematically selected sample of 510 occupational therapists and occupational therapy assistants. The response rate was 74%. RESULTS: The use of occupational therapy aides is prevalent in a variety of settings. Forty percent of respondents reported that they currently work with aides, whereas 23% reported that they have never worked with aides. Occupational therapy aides perform a variety of tasks and receive various levels and amounts of supervision and training. Of those respondents who delegated specific skilled tasks to aides, 76% reported daily contact for purposes of supervision and training. Nineteen percent who currently work or have worked with aides reported being in a situation where an ethical issue arose related to aide use. CONCLUSION: On the basis of the data, it is suggested that occupational therapy practitioners would benefit from taking a proactive role in determining how aides can be used to maximize service delivery while maintaining quality services. There also appear to be ethical concerns related to appropriate delegation of tasks to aides and to their supervision and training.     

Experimental equations to calculate aminoglycoside clearances through cuprophan dialyzers

Aminoglycosides are a group of antibiotics of particular interest because of their widespread use in the treatment of infections caused by gram-negative bacteria. However, they are difficult to dose accurately because of their narrow therapeutic range and overdosing produces a large number of toxic effects. This paper describes a study carried out with the aim of ensuring the accurate administration of these antibiotics in end-stage renal disease patients undergoing hemodialysis, by developing equations which enable the dosage for individual patients to be calculated according to the dialyzer being used and the operational conditions set up during the dialysis session.