反复呼吸道感染与微量元素的相关性研究

为探讨反复呼吸道感染与微量元素锌、铜、铁、钙的关系,剪取枕后下头发0．5－1g,采用电感耦合高频等离子体发射光谱法检测了头发微量元素。结果表明：（1）反复呼吸道感染患儿发锌、铜、铁、钙含量明显低于正常健康儿童,差异有极显著性（P均＜0．01）。（2）反复呼吸道感染患儿经过补充微量元素后,发锌、铜、锌、钙含量明显高于补充微量元素前,有显著性（P＜0．01或＜0．05）。（3）56例反复呼吸道感染患儿经过补充微量元素后,随访其后1年内呼吸道感染次数的变化,明显减少者占80．4％;基本没变者占19．6％。可见,微量元素缺乏是引起反复呼吸道感染的重要原因之一。补充微量元素可减少呼吸道感染的次数。     

冠心病与微量元素锌铜硒

以临床典型冠心病案为例，探讨了中医中药传统和微量元素关系，重点讨论了微量元素锌、铜、硒与冠心病的病因病理和治疗的关系。     

肾病综合征与锌铜铁

以临床典型肾病综合征病案为例，地中医中药传统理论和微量元素研究关系，重点了微量元素锌、铜、铁与肾病综合征的病因病机和治疗关系。     

精亏不育与锌锰

以临床典型精亏不育病案为例，探讨了中医中药传统和微量元素的关系，重点讨论了微量元素锌、锰、与精亏不育的病因病理和治疗的关系。     

肾炎的中医药论治与微量元素

以临床典型肾病病案为例，探讨了中医中药传统理论和微量元素研究的关系，重点讨论微量元素锌，铁，铜与肾病的病因，病机和治疗关系。     

福利院人群微量元素第三年度观察与分析

微量元素检测及临床观察是在深圳市社会福利中心（福利院）人群中开展了三年的市级科研项目，通过了解这些人群体内6种微量元素含量，为微量元素与健康及相关性疾病的临床研究提供科学依据。与上年度比较，福利院人群体内的有益微量元素普遍有所下降，低铁、低钙，尤其以低钙明显，临床发病率、住院率有所上升，特别是肠道疾病明显升高。福利院需要继续改善生活环境，增加富含有益微量元素饮食；疾病要以预防为主，膳食合理，营养均衡，微量元素检查应列为常规项目。     

94例发锌发钙值偏低患儿的临床主症分析与疗效观察

分析了９４例患儿头发微量元素含量。结果表明：患儿厌食、偏食、反复上呼吸道感染、多汗与体内微量元素与必需元素异常关系密切,特别是锌、钙缺乏更为明显。根据祖国医学“脾呼则口能知五味”、“肺主气属卫”的理论,采用针刺以疏通经络,调整脾胃功能,内服锌、钙制剂脉动这脾通便、补益肺气等中药治疗,治疗时间短,疗效提高,临床有效率达９０％以上。     

帕金森氏病与头发中微量元素关系的研究

以人发为材料，探讨了帕金森氏病与微量元素的关系。采集了６０例患者头发和５０例健康人头发，用电感耦合高频等离子体发射光谱仪进行测定，结果发现，患者组头发铜、锌、铁、锰明显低于对照组，患者组轻、中、重分型病人的头发微量元素变化有一定的规律，上述结果提示微量元素与帕金森氏病有重要关系。     

高血压类风湿症疗效与锌,钙关系初探

以临床典型病案为例，探讨了中医中药传统理论和现代微量元素研究的关系，重点讨论了向量元素锌、宏量元素钙与高血压、风湿症的病因病机和治疗关系。     

中药方剂中微量元素与四性关系的研究

本文用化学计量学方法从整体上探讨微量元素含量与中药方剂的药性的相关性。对１１０首方剂中３３种微量元素测定数据，因子分析和聚类分析进行多变量分析。因子分析证实了一个十因子模型能合理解释这些微量元素间的相关关系。样本聚类分析能把１１０首方剂聚类成不同组。１１０首方剂的数值分类结果与以组方药物定性和方剂功用定性有良好的一致性，正确分类能力６８．２％，从而揭示了方剂的温热。寒凉性质与微量元素的内在关系。     

Interlaboratory comparison study on PCDDs and PCDFs in cow's milk

Summary Six laboratories in four European countries (GER, GB, S, NL) have conducted an interlaboratory comparison study on the analysis of dioxins in cow's milk. The study comprised a cross comparison of standards and the analysis of the 2,3,7,8-substituted congeners of PCDD/Fs in three different milk pools (no spiking). Participants used their own procedures and methods for the determination of the fat content and PCDD/F levels in biological samples, all using non-polar gas chromatography and medium to high resolution mass spectrometry (RP=3.000–10.000). Quantification was performed by the use of a common quantification standard mixture of the native PCDD/Fs (4 labs) or the own quantification standards (2 labs). Within-laboratory reproducibilities for the determination of the major toxic congeners and the total TCDD toxicity equivalence (TE) level were between 2 and 16% (RSD) with a mean variation of 6% on TE basis. The interlaboratory comparison for TE values agreed within 10–17% (RSD) for TE values between 10.4 and 2.8 pg TE/g milk fat. Reliabilities of both participants and the common standards were difficult to assess and probably less good than expected. Differences in these standards were typically within 25% of expected concentrations up to 50% for some congeners by some laboratories.     

糖尿病人微量元素谱的多元分析

胜多元分析了糖尿病患者样品中微量元素，了解微量元素与糖尿病的关系，并提出了新见解。用ＩＣＰ－ＡＥＳ测定糖尿病患者血、发中１８种微量和宏量元素 ；结果经多元分析处理，找到血、发共有的相关链：Ｍｎ－Ｎｉ－Ｃｕ－ＳｒＴｉ，它与患者年龄、性别、样品无关，看来它提供了机体的特殊信息。     

Macrolactamization of glycosylated peptide thioesters by the thioesterase domain of tyrocidine synthetase

The 35 kDa thioesterase (TE) domain excised from the megadalton tyrocidine synthetase (Tyc Syn) retains autonomous capacity to macrocyclize peptidyl thioesters to D-Phe1-L-Leu10-macrolactams. Since a number of nonribosomal peptides undergo O-glycosylation events during tailoring to gain biological activity, the Tyc Syn TE domain was evaluated for cyclization capacity with glycosylated peptidyl-S-NAC substrates. First, Tyr7 was replaced with Tyr(beta-D-Gal) and Tyr(beta-D-Glc) as well as with Ser-containing beta-linked D-Gal, D-Glc, D-GlcNAc, and D-GlcNH2, and these new analogs were shown to be cyclized with comparable kcat/Km catalytic efficiency. Similarly, Gal- or tetra-O-acetyl-Gal-Ser could also be substituted at residues 5, 6, and 8 in the linear decapeptidyl-S-NAC sequences and cyclized without substantial loss in catalytic efficiency by Tyc Syn TE. The cyclic glycopeptides retained antibiotic activity as membrane perturbants in MIC assays, opening the possibility for library construction of cyclic glycopeptides by enzymatic macrocyclization.     

Transesterification,morphology and some mechanical properties of thermotropic liquid crystal polymers/polycarbonate blends

Blends of polycarbonate (PC) and thermotropic liquid crystal polymer Vectra-A (VA), with up to 20 wt.% VA were prepared at temperatures up to 320°C. Transesterification (TE) was found to take place notably at the highest blending temperature. At this temperature, it increased linearly with the VA content. TE products, located at PC/VA interfaces led to reductions in the size of dispersed phase droplets, as shown by scanning electron microscopy. The inference of increased compatibility was consistent with improvements in mechanical property parameters of the blends. These also showed that mixing time was a factor in defining interfacial states. Acid–base interaction data gave further evidence of the presence of TE products, notably when blending occurred at 320°C, and suggested that ∼10 wt.% of VA was needed to saturate interfaces with PC. The absolute values of acid and base interaction constants were found to be very low, confirming earlier evidence that near 320°C dispersion forces are dominant at PV/VA interfaces, contributing to enhanced compatibility in blends prepared at these high temperatures.     

Gas chromatography/mass spectrometry based hair steroid profiling may reveal pathogenesis in hair follicles of the scalp

A method of steroid profiling, including androgens, progestins, corticoids and sterols, was developed to evaluate the concentrations of steroids as well as the activities of the enzymes responsible for steroidogenesis in hair by gas chromatography/mass spectrometry. The extraction efficiencies of steroids from the hair matrix were improved by ultrasonication for 1 h at 50 °C. The overall recoveries ranged from 71 to 132%, with a limit of quantification for all analytes ranging from 1 to 50 ng/g. The devised method was used to identify the metabolic changes for both male‐pattern baldness (MPB) and the drug efficiency of dutasteride, which inhibits 5α‐reductase. Increased dihydrotestosterone levels and the dihydrotestosterone/testosterone (DHT/T) ratio, which is responsible for the 5α‐reductase activity, were observed in the MPB patients. A dutasteride treatment resulted in decreases in the DHT and 5α‐androstanedione concentrations and DHT/T ratio in the hair samples. Hair steroid profiling reflects the sebaceous status in the scalp and may be useful for monitoring the metabolic responses to both the disease and drug actions. Copyright © 2011 John Wiley & Sons, Ltd.     

Recent Advances and Perspectives in Analytical Methodologies for Monitoring the Bioavailability of Trace Metals in Environmental Solid Substrates

In the last decades, researchers have realised that the impact of trace elements (TE) in environmental solid substrates on ecological systems and biota cannot be ascertained appropriately by means of total metal content measurements. Assessment of TE chemical forms, types of binding and reactivity of their associations with particulate forms has, thus, been commonly performed via batch-wise equilibrium-based sequential extraction fractionation methods able to discern TE bound to different soil-phase compartments. In this paper, novel analytical strategies for monitoring the mobility, bioavailability and the eventual impact of anthropogenic TE in environmental solids are addressed. The potential of passive dosimeters based on microdialysis sampling for on-site, real-time monitoring of chemical contaminants in pore soil solution is thoroughly discussed and critically compared with active microsamplers. Recent miniaturised configurations designed for following the fate of target pollutants and the on-going chemical changes occurring at local soil sites, e.g., the rhizosphere environment, at high temporal resolution are also presented in detail. Kinetic information on the lability of the various TE forms associated to soil phases under simulated environmental changing conditions – that yield improved knowledge on short-term hazards of TE for the environment – can be obtained in a fully automated mode by means of flow-through microcolumn fractionation procedures. The use of sequential injection analysis, in terms of the implementation of on-line dynamic fractionation, is described and illustrated via selected examples comprising the well-accepted three-step SM&T sequential fractionation, protocol.     

Total versus effective total efficiency in the computation of coincidence summing corrections in gamma-ray spectrometry of volume sources

For the evaluation of coincidence summing effects for volume sources an effective total efficiency (ETE) is used instead of the common total efficiency (TE). In this paper ETE is computed by the Monte Carlo method. The differences between ETE and TE are analyzed and their origin is discussed. Measured values for the coincidence summing correction factors for a standard solution containing ¹⁵²Eu in a one liter Marinelli beaker are compared with computed values obtained from appropriate values of ETE. It is shown that the procedure for the evaluation of the coincidence effects is reliable. As a consequence it can be concluded that ¹⁵²Eu volume sources can be successfully used for efficiency calibration even in the case of high-efficiency detectors and close source-to-detector distances.     

Improvement of the moderator’s thermalization efficiency for 14 MeV neutrons in boron neutron capture therapy

In boron neutron capture therapy (BNCT), the proportion of the fast neutron in the tumor (PFN) must be no more than 3%. If a D–T neutron generator is used as a thermal neutron source in BNCT, the moderator must be optimized to decrease the PFN. Based on the analysis of the theory, water, heavy water, polythene, graphite, lead, and tungsten were used to moderate the fast neutrons. If the three-layer material is composed of a 4 cm thickness layer of tungsten, a 13 cm thickness layer of lead, and a 23 cm thickness layer of heavy water, its thermalization efficiency (TE) is highest, which is increased by 191.5% than the maximum TE moderated by single-layer materials and by 19.3% than the maximum TE moderated by double-layer materials.     

Anion-exchange supermacroporous monolithic matrices with grafted polymer brushes of N,N-dimethylaminoethyl-methacrylate

Graft polymerization using potassium diperiodatocuprate as initiator was found to be an effective and convenient method for grafting functional polymer of N,N-dimethylaminoethyl methacrylate (DMAEMA) onto superporous polyacrylamide gels, so-called cryogels (pAAm cryogels). It was possible to achieve grafting degrees up to 110% (w/w). The two-step graft polymerization i.e. first activation of the matrix followed by displacement of initiator solution with the monomer solution, decreased pronouncedly the soluble homopolymer formation. The efficiency of graft polymerization using a two-step technique increased up to 50% (w/w) at a monomer conversion of 10%, compared to 10% graft efficiency with 60-70% monomer conversion for one-step direct graft polymerization. The pAAm cryogels grafted in one-step and two-step procedures, respectively, behaved similarly when binding low-molecular weight ligand but showed very different behavior for sorption of a high-molecular-weight ligand, bovine serum albumin (BSA). The differences in behavior were rationalized assuming different structure of the graft polymer layers and tentacle-type BSA binding to the grafted polymer.     

Determination of niobium and tantalum in binary alloys and zirconium alloys

Recent developments in the metallurgy of niobium, tantalum and zirconium have necessitated provision of analytical procedures for determining niobium and tantalum in the presence of each other and in the presence of zirconium. For this purpose, absorptioinetric procedures based on the formation of yellow coloured complexes, between pyrogallol and niobium or tantalum, have been critically examined. Direct absorptiometric procedures are described, which are suitable for determining niobium or tantalum in the range 2 to 7%; when either of these metals exceeds 7%, differential absorptiometric procedures are recommended. Corrections must lie made for absorption due to the presence of other metals which form complexes with pyrogallol. In tlie determination of niobium or tantalum up to 5%, the precision of the method is about ±0.05%. About 12 determinations can be made in a day, by one analyst.