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981.
杨学武 《广东微量元素科学》2017,24(5)
突发公共卫生事件一直是政府组织十分关注的问题。当前,在公共卫生事件出现高频率的发生几率后,健康教育工作已占据着越来越重要的地位。从宏观角度来说,突发公共卫生事件是一个涵盖范围十分广泛的事件内容,其事件包含了多个可预测与不可预测的突发状况,也包含了任何地点、任何社会群体以及任何事件当中,因此在健康教育上,需从宏观范围进行全面计划,以系统式方式对各个突发公共卫生事件做出针对性教育,且对教育内容作出可行性评估,切实保障健康教育对突发公共卫生事件有一定的作用及影响力。对此,为进一步探讨该话题,针对突发公共卫生事件健康教育基本策略展开详细探讨。 相似文献
982.
建立藏红T共振瑞利散射光谱法测定保健食品中透明质酸钠的含量。在p H 5.00的Britton–Robinson缓冲介质中,藏红T与透明质酸钠反应形成化合物,使溶液共振瑞利散射急剧增强并产生相应的散射光谱,其最大散射峰位于335 nm,5.0×10~(–4) mol/L藏红T溶液用量为0.70 m L,反应时间为15 min。透明质酸钠的质量浓度在0.06~3.0mg/L范围内与共振瑞利散射增强程度成良好的线性关系,线性相关系数为0.999 2。方法检出限为19.8μg/L,测定结果的相对标准偏差为3.36%~4.52%(n=6),加标回收率为92.4%~103.0%。该方法灵敏度高、选择性好、操作简便,适用于保健食品中透明质酸钠的测定。 相似文献
983.
984.
In modern medicine, commonly used biomaterials originating from metals, ceramics and polymers have shown biocompatibility with blood, tissues, cells, etc., in the human body. Polymeric biomaterials are usually understood as polymeric materials and articles made from them which are used in medicine, biotechnology biomedicine, bioengineering, pharmaceutical, veterinary, food industry, agriculture and related fields. In this in vitro study, swellings and the biocompatibility of environmentally sensitive N-isopropyl acrylamide-based (ES) hydrogels such as N-isopropyl acrylamide/acrylamide (ES/0), and N-isopropyl acrylamide/acrylamide/ carboxylic acids (ES/XAc) prepared by free radical polymerization in aqueous solutions has been investigated. Selected carboxylic acids for this study were acrylic, methacrylic, crotonic, itaconic, maleic, mesaconic and aconitic acid. The equilibrium swelling of the hydrogels are investigated in simulated physiological fluids or crystalloid solutions such as HCl-KCl buffer (pH = 1.1), universal buffer (pH = 5.5), phosphate buffer (pH = 7.4), urea, isotonic NaCl, isotonic KCl, 5% dextrose, 5% dextrose+isotonic NaCl, Ringer's lactate, human blood serum and human serum albumin solution at 37°C. For the analysis of biocompatibility, ES hydrogels are incubated in 5 different human sera and their biocompatibilities with some biochemical parameters have been investigated for 24 h at 37°C. No significant differences in values before and after the test procedures have been found. It is therefore concluded that environmentally sensitive N-isopropyl acrylamide-based hydrogels are biocompatible for biochemical parameters of human sera. 相似文献
985.
The use of highly purified immunoglobulin became among the most powerful adopted strategies in therapeutic trials nowadays. Their role as immunomodulatory and anti-inflammatory agents has widened their scope of use. A novel continuous supermacroporous monolithic cryogels embedded with histidine-epoxy-activated-sepharose beads were synthetized as a new monolithic adsorbents for the separation of immunoglobulin G from human serum. The histidine-epoxy-activated-sepharose beads were embedded into the 2-hydroxyethyl methacrylate (HEMA) cryogels present in frozen aqueous solution inside a plastic syringe. The microstructure morphology of the cryogels was characterized by swelling measurement and scanning electron microscopy. The adsorption of human IgG on the histidine-epoxy-activated-sepharose beads pHEMA cryogels appeared to follow the Langmuir–Freundlich adsorption isotherm model. The maximum IgG adsorption was observed at 4°C and pH 7.4 and was found to be 26.95 mg/g of cryogel which is close to that obtained experimentally (24.49 mg/g). The cryogels were used for several adsorption-desorption cycles without any negligible decrease in their adsorption capacity. 相似文献
986.
《Journal of mass spectrometry : JMS》2017,52(3):144-151
To improve our understanding of the electrospray ionization (ESI) process, we have subjected equimolar mixtures of salts A+X− (A+ = Li+, NBu4+; X− = Br−, ClO4−, BF4−, BPh4−) in different solvents (CH3CN, tetrahydrofuran, CH3OH, H2O) to negative‐ion mode ESI and analyzed the relative ESI activity of the different anionic model analytes. The ESI activity of the large and hydrophobic BPh4− ion greatly exceeds that of the smaller and more hydrophilic anions Br−, ClO4− and BF4−, which we ascribe to its higher surface activity. Moreover, the ESI activity of the anions is modulated by the action of the counter‐ions and their different tendency toward ion pairing. The tendency toward ion pairing can be reduced by the addition of the chelating ligands 12‐crown‐4 and 2.2.1 cryptand and is, although to a smaller degree, further influenced by the variation of the solvent. Complementary electrical conductivity measurements afford additional information on the interactions of the ionic constituents of the sample solutions. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
987.
Marco Bee Giuseppe Espa Diego Giuliani Flavio Santi 《Journal of computational and graphical statistics》2017,26(3):695-708
In this article, we use the cross-entropy method for noisy optimization for fitting generalized linear multilevel models through maximum likelihood. We propose specifications of the instrumental distributions for positive and bounded parameters that improve the computational performance. We also introduce a new stopping criterion, which has the advantage of being problem-independent. In a second step we find, by means of extensive Monte Carlo experiments, the most suitable values of the input parameters of the algorithm. Finally, we compare the method to the benchmark estimation technique based on numerical integration. The cross-entropy approach turns out to be preferable from both the statistical and the computational point of view. In the last part of the article, the method is used to model the probability of firm exits in the healthcare industry in Italy. Supplemental materials are available online. 相似文献
988.
《Angewandte Chemie (International ed. in English)》2017,56(51):16126-16134
The chemistry of gold strongly focuses on the ubiquitous oxidation states +I and +III. The intermediate oxidation state +II is generally avoided in mononuclear gold species. In recent years, gold(II) has been increasingly suggested as a key intermediate in artificial photosynthesis systems, with gold(III) moieties acting as electron acceptors, as well as in gold‐catalyzed photoredox catalysis and radical chemistry. This Minireview provides a concise summary of confirmed and characterized mononuclear open‐shell gold(II) complexes. Recent findings on structural motifs and reactivity patterns will be discussed. Exciting developments in the fields of photosynthesis, photocatalysis, and potential roles in medicinal chemistry will be outlined. 相似文献
989.
Single nucleotide polymorphisms (SNPs) are the most common genetic polymorphisms and play a major role in many inherited diseases. Methylenetetrahydrofolate dehydrogenase 1 (MTHFD1) is one of the enzymes involved in folate metabolism. In the present study, the functional and structural consequences of nsSNPs of human MTHFD1 gene was analyzed using various computational tools like SIFT, PolyPhen2, PANTHER, PROVEAN, SNAP2, nsSNPAnalyzer, PhD-SNP, SNPs&GO, I-Mutant, MuPro, ConSurf, InterPro, NCBI Conserved Domain Search tool, ModPred, SPARKS-X, RAMPAGE, FT Site and PyMol. Out of 327 nsSNPs form human MTHFD1 gene, total 45 SNPs were predicted as functionally most significant SNPs, among which 17 were highly conserved and functional, 17 were highly conserved and structural residues. Among 45 most significant SNPs, 15 were predicted to be involved in post translational modifications. The p.Gly165Arg may interfere in homodimer interface formation. The p.Asn439Lys and p.Asp445Asn may interfere in binding interactions of MTHFD1 protein with cesium cation and potassium. The two SNPs (p.Asp562Gly and p.Gly637Cys) might interfere in interactions of MTHFD1 with ligand. 相似文献
990.
Metal–support cooperative catalysts have been developed for sustainable and environmentally benign molecular transformations. The active metal centers and supports in these catalysts could cooperatively activate substrates, resulting in high catalytic performance for liquid‐phase reactions under mild conditions. These catalysts involved hydrotalcite‐supported gold and silver nanoparticles with high catalytic activity for organic reactions such as aerobic oxidation, oxidative carbonylation, and chemoselective reduction of epoxides to alkenes and nitrostyrenes to aminostyrenes using alcohols and CO/H2O as reducing reagents. This high catalytic performance was due to cooperative catalysis between the metal nanoparticles and basic sites of the hydrotalcite support. To increase the metal–support cooperative effect, core–shell nanostructured catalysts consisting of gold or silver nanoparticles in the core and ceria supports in the shell were designed. These core–shell nanocomposite catalysts were effective for the chemoselective hydrogenation of nitrostyrenes to aminostyrenes, unsaturated aldehydes to allyl alcohols, and alkynes to alkenes using H2 as a clean reductant. In addition, these solid catalysts could be recovered easily from the reaction mixture by simple filtration, and were reusable with high catalytic activity. 相似文献