羧基化多壁碳纳米管修饰电极伏安法测定多巴胺

目的 :研究用羧基化多壁碳纳米管修饰电极伏安法测定痕量多巴胺 (DA)的效果。方法 :采用涂布法制成羧基化多壁碳纳米管修饰电极 ;在pH =5 .4的KH2 PO4 Na2 HPO4缓冲溶液中 ,采用该修饰电极伏安法测定DA。结果 :该修饰电极对DA有着显著的电催化作用 ,与裸玻碳电极相比较 ,其灵敏度大大提高 ,在2 .0× 10 -7～ 6 .0× 10 -4mol/L浓度范围内 ,DA的氧化峰电流与浓度成良好的线性关系 ,检测限为 5 .0× 10 -8mol/L。将该修饰电极用于盐酸多巴胺针剂的测定 ,相对平均偏差为 1.4 % ,平均回收率为 99.2 %。结论 :该修饰电极响应快 ,灵敏度高 ,稳定性好 ,寿命长 ,适合于具有电活性生物分子的测定     

Evaluation of dietetic activity analysis (DAA)—a system for data collection in clinical dietetics

A system of data collection and analysis based on patient visits was evaluated over a four-week period in five districts and a six-month period in one district by twenty-five dietitians. Each patient visit was analysed by diagnosis (the problem), by diet (the treatment) and by nutritional care level (the action). The system was seen to encourage self analysis by dietitians and proved a useful educational tool in addition to providing dietetic managers with data on clinical dietetic activity. It was considered successful and well accepted in four of the six districts.     

Oral Controlled Release Technology for Peptides: Status and Future Prospects

In spite of significant efforts in academic and commercial laboratories, major breakthroughs in oral peptide and protein formulation have not been achieved. The major barriers to developing oral formulations for peptides and proteins include poor intrinsic permeability, lumenal and cellular enzymatic degradation, rapid clearance, and chemical and conformational stability. Pharmaceutical approaches to address these barriers, which have been successful with traditional, small, organic drug molecules, have not readily translated into effective peptide and protein formulations. The success achieved by Sandoz with cyclosporin formulations remains one clear example of what can be achieved, although it is likely that effective oral formulations for peptides and proteins will remain highly compound specific. Although the challenges are significant, the potential therapeutic benefit remains high, particularly with the increasing identification of potential peptide and protein drug candidates emerging from the biotechnology arena. Successful formulations will most likely require a systematic and careful merger of formulation and design delivery systems which maximize the potential for absorption across the epithelial cell layer.     

一类“近乎双线性”系统及其稳定化反馈控制

本文定义了一类“近乎双线性”系统。可用以近似一类奇异摄动双线性系统,而且可以描述某些实际工业对象。并发现其控制器的设计较方便。文中还给出了一种简单的反馈控制器的设计方法。又对一类多输入双线性系统,提出一种设计反馈控制器的改进方案,根据Lyapunov定理得到一非线性反馈控制律。以上设计方法分别对某合成氨反应器作了应用研究,仿真结果表明了方法的有效性。     

Determination of tryptamine in rat brain by gas chromatography-mass spectrometry

Tryptamine (TA) occurs in trace levels in the brain, but its role in the central nervous system is not clear. However, there is evidence that TA may be a neuromodulator since it binds to specific binding sites in the brain. TA was measured as a diheptafluorobutyryl derivative in rat whole brain by capillary gas chromatography—mass spectrometry using negative chemical ionization (NCI) and single ion monitoring (SIM). d₄-TA was used as the internal standard. The ions m/z 532 and m/z 536 were monitored to identify TA and d₄-TA, respectively and to calculate the concentration of TA in rat whole brain which was found to be 0.19 ± 0.08 ng g⁻¹ (n = 8). The results confirm the earlier TA concentrations measured by GC—MS using positive electron impact ionization. However, NCI improved the signal/noise ratio of the method increasing its sensitivity for TA.     

The Relationship of pK a and Acute Skin Irritation in Man

The relationship between pK _a and skin irritation in man is studied for a homologous series of benzoic acid derivatives, which permeate through human skin at comparable rates (15–88 µg/cm²/hr). Skin irritation and pK _a are correlated for pK _a 4. Laser Doppler velocimetric assessment of skin blood flow, color meter readings, erythema, edema, and the primary irritation index are all linearly correlated and related to pK _a, erythema at 24 hr appears to be the most sensitive parameter to variation in pK _a when pK _a 4.     

针灸治疗慢性非特异性腰痛随机对照试验结局指标的现状研究

背景 针灸是治疗慢性非特异性腰痛(CNSLBP)的重要方法。随着研究的发展,大量针灸治疗CNSLBP的随机对照试验(RCT)已经发表,但由于在结局指标选择方面存在一定的问题,严重限制了高质量临床证据的产生。目的 评价针灸治疗CNSLBP RCT选用的结局指标情况,为针灸治疗CNSLBP相关研究提供参考依据。方法 系统检索4个中文数据库(中国知网、维普网、万方数据知识服务平台、中国生物医学文献服务系统)、3个英文数据库(PubMed、Embase、Cochrane Library)2017-01-01至2022-03-15发布的针灸治疗CNSLBP的文献,以及自建库以来至2022-03-15发表的非特异性腰痛(NSLBP)的核心结局指标集(COS)。对纳入的针灸治疗CNSLBP的文献基本特征进行分析,对文献的临床结局指标进行归类,对文献中的结局指标及《中医病证诊断疗效标准》的应用现状进行分析。分析NSLBP研究的COS现状,比较其与现有针灸治疗CNSLBP文献结局指标的异同。结果 本研究纳入的针灸治疗CNSLBP的49篇文献均为RCT,共包含4篇英文文献和45篇中文文献。共包含4 272...     

装潢居室空气中挥发性化学物的遗传毒性研究

目的探讨装潢居室空气中挥发性化合物的遗传毒性.方法采用小鼠骨髓嗜多染性红细胞微核试验和小鼠精子畸形试验检测居室装潢后空气中挥发性化合物的遗传毒性.结果该化合物对小鼠呼吸系统有明显的刺激作用,与阴性对照组比较,高、中、低剂量组的微核率、精子畸形率均有显著差异性.结论居室装潢后室内空气中挥发性化合物具有遗传毒性作用.     

Beta-carotene-containing preparation carinat inhibits lipid peroxidation and development of renal tumors in rats treated with chemical carcinogen

The effects of pretreatment with β-carotene-containing preparation carinat on the development of renal tumors in rats receiving single intravenous injection of chemical carcinogen 3-(1-α-L-arabinopyranosyl)-1-methyl-1-nitrosourea were studied. Fourteen months after carcinogen administration, the degree of lipid oxidation in rat kidneys 2.5-fold surpassed that in animals receiving carinat in a dose producingin vivo antioxidant effect. Carinat decreased the total number of induced tumors and the incidence of mesenchymal renal tumors and suppressed the development of multiple tumors. The accumulation of lipoperoxides in the kidneys during carcinogenesis is associated with activation of free radical processes and carcinogen-induced inhibition of lipoperoxide enzymatic degradation and probably promotes renal malignancies due to co-carcinogenic action of these compounds. The data suggest that carinat-induced suppression of tumor development attests to antioxidant effects of β-carotene. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 130, No. 7, pp. 95–97, July, 2000     

Stretching the limits: Stem cells in regeneration science

The focus of regenerative medicine is rebuilding damaged tissues by cell transplantation or implantation of bioartificial tissues. In either case, therapies focus on adult stem cells (ASCs) and embryonic stem cells (ESCs) as cell sources. Here we review four topics based on these two cell sources. The first compares the current performance of ASCs and ESCs as cell transplant therapies and the drawbacks of each. The second explores somatic cell nuclear transfer (SCNT) as a method to derive ESCs that will not be immunorejected. The third topic explores how SCNT and ESC research has led to the ability to derive pluripotent ESCs by the dedifferentiation of adult somatic cells. Lastly, we discuss how research on activation of intrinsic adult stem cells and on somatic cell dedifferentiation can evolve regenerative medicine from a platform consisting of cell transplantation to one that includes the chemical induction of regeneration from the body's own cells at the site of injury. Developmental Dynamics 237:3648–3671, 2008. © 2008 Wiley‐Liss, Inc.