脱发白发与微量元素关系研究

利用火焰原子吸收法测定了中国银行韶关节市分行４５８名职工头发中Ｃｕ，Ｆｅ，Ｚｎ，Ｃａ含量，运用统计学方法求出该人群中正常者与白发，脱发者Ｃｕ，Ｆｅ，ＺｎＣａ的特征含量，通过数据比较可看出，白发者Ｃｕ，Ｆｅ，Ｚｎ，Ｃａ的含量均低于正常组，而脱发者与正常组较接近，经相关性检验，证明了Ｃｕ，Ｆｅ，Ｚｎ，Ｃａ偏低的血发存在的相关性，与脱发没有相关性，经过性别比对，女性发中Ｃｕ，Ｆｅ，Ｚｎ，Ｃａ含量均高于男     

用ICP研究鹿科动物骨质疏松症的微量元素特征

鹿科动物的骨质疏松症是近几年出现的一种疾病，它影响鹿的生长发育和繁殖，病重者死亡。我们采集梅花鹿和白唇鹿的毛，血样，用低温灰化方法和温法消解处理样品，用ＩＣＰ分析了毛，血清中微量元素的含量。病梅花鹿毛样中Ｍｇ，Ａｌ，Ｃａ，Ｔｉ，Ｆｅ，Ｃｕ，Ｚｎ的含量比正常组高，Ｔｉ，Ｃｕ，Ｚｎ的偏差率大于１５％，而Ｓｉ，Ｍｎ，Ｐ，Ｐ，Ａｇ，Ｂａ，Ｌａ，Ｃｅ，Ｐｂ比正常组低，Ｖ，Ａｇ，Ｂａ，Ｌａ，Ｃｅ，Ｐｂ存在...     

中国稀土科技文献索引(1997)

固体物理、固体化学与新材料424Tin'"，YP"共掺ZBLAN玻璃中的能量传递与转换，冯衍等，物理学报，1997，46（12），2454．425LqO。基导电白瓷高祖电用率的国试和研究，李友芬等，中国有色金属学报，1997，7（l），159．4M环氧树脂粘结SIDZFq，N。磁体的矫顽力机理，于申军等，磁性材料及器件，1997，28（l），16．427SmZFq7Nyq稀土永巴材料的最近进展，吴安国，磁性材料及器件，1997，28（l），46．428重稀土锰基化合物Gd（回n，Co）St的结构与殓性，林钢等，磁性材料及器件，1997，28（2），19．4N制粉过程对SwFq，N。各向异性…     

硝酸铈对大鼠体内酯酶酶谱的影响

采用聚丙烯酰胺凝胶电泳技术，研究了含不同浓度的稀土饲料喂养大鼠对大鼠体内9种器官和组织中（心脏，肝脏，肾脏，肌肉，胃，血清，睾丸，胰腺，肺）酯酶酶谱的影响，结果表明：稀土的作用导致酯酶酶谱发生显著的变化，原有的一些谱带消失，出现了一些新的谱带，这种影响随器官和组织的不同而不同，谱带强度的改变也因器官和稀土浓度不同而异。特别是在心，肝，肾，肌，胃中酯酶（EST）同工酶酶谱和稀土的浓度之间具有一定的相关性，对酶活性起着抑制或和激活作用，面对血清，睾丸，胰腺，肺中EST同工酶的影响则相对较小，可见，稀土对大鼠体内酯酶酶谱的影响是广泛而显著的。     

一种全自动光度滴定仪

报道了改装７２１型分光光度计为光度滴定仪并联用８０３１单片微机构成一台全自动光度滴定仪，在单片机的控制下，实现取样，加试液，搅拌，开关光门，调零，调参比，滴定，测吸光度，数据处理，显示结果并打印，排除废液，冲洗滴定池等操作过程的全自动化，约１１０ｓ可完成一次测定，误差〈０．２％，ＲＳＤ〈１．５％，测定快速，准确，重复性好，可胜任在线监测工作，也可作常规滴定分析。     

大肠癌与溃疡性结肠炎患者血清微量元素测定

用ＩＣＰ－ＡＥＳ方法，对３０例大肠癌，２６例溃疡性结肠炎进行血清钼，锌，铬铁，铜，锰，铅，铝，硒，铋，钡，钛，钴，钒等微量元素测定，并与２０例健康者对照。结果显示大肠癌组血清钼，锌，铬，低于对照组钼，锌，铬，Ｐ分别〈０．０１，〈０．０５，〈０．０５；溃疡性结肠炎组钼低于对照组，Ｐ〈０．０５。提示微量元素代谢异常可能直接影响酶系统，使自由基失控，体内促氧化和抗氧化平衡失调，促使肿瘤的发生。     

仙人掌果汁红色素含量测定与微量元素分析

用可见分光光度法与等离子体发射光谱法对仙人掌果汁色素及其微量元素的含量进行了测定，仙人掌果汁色素含量达２．１％￣３．３％，成熟果的果汁色素含量比预成熟果大。在２７种被测定的元素中，除Ａｓ、Ｂｅ、Ｃｄ、Ｃｏ、Ｍｏ、Ｐｂ，Ｓｂ，Ｔｌ等未被检出外，其余Ａｇ，Ａｌ，Ｂ，Ｂａ，Ｃａ，Ｃｒ，Ｃｕ，Ｆｅ，Ｍｇ，Ｍｎ，Ｎａ，Ｎｉ，Ｓｅ，Ｖ，Ｚｎ，Ｋ，Ｐ，Ｓ等均有准确测定值。成熟果与预成熟果的果汁微量元素含量无明显     

乙酰丙酮－5，10，15，20－四－（对戊氧基苯基）卟啉及镱配合物的合成与表征

乙酰丙酮－５，１０，１５，２０－四－（对戊氧基苯基）卟啉及镱配合物的合成与表征李冬梅，刘国发，师同顺，林闽，刘玉文，邹明珠，曹锡章，刘晓勋（吉林大学化学系，长春，１３００２３）（吉林大学分析测试中心）关键词乙酰丙酮，四－（对戊氧基苯基）卟啉，镱的配合...     

聚苯乙烯，聚甲基丙烯酸甲酯对聚氯乙烯／氯化聚乙烯共混体流变性的影响

聚苯乙烯，聚甲基丙烯酸甲酯对聚氯乙烯／氯化聚乙烯共混体流变性的影响杨文君，吴其晔，杜华（青岛化工学院高分子材料系，青岛，２６６０４２）王建民，李应华，张宝善（齐鲁石化研究院，淄博，２５５４３４）关键词塑料改性，流变性，聚氯乙烯，氯化聚乙烯，刚性粒子我...     

新型三氟甲基吡啶类衍生物的合成及生物活性测试研究

新型三氟甲基吡啶类衍生物的合成及生物活性测试研究钱旭红，唐军，陈卫东，张荣，黄德音，倪长春，郭庆铭（华东理工大学农用化学品研究所，上海，２００２３７）（上海市农药研究所）关键词氟代物，吡啶，合成，生物活性，化学农药不少吡啶类化合物是有着广泛前途的生物...     

Dimerization of Resveratrol Induced by Red Light and Its Synergistic Analgesic Effects with Cobra Neurotoxin

Resveratrol polymer has better effects than monomer in some aspects as reported, but most of synthetic methods acquire severe conditions and no analgesic effects are investigated. A novel method is found to synthesize resveratrol polymer by excitation of photosensitizer pheophorbide at red light of 630 nm. The polymer was analyzed by fluorescence spectra and HPLC, further isolated by preparative liquid chromatography and identified as a resveratrol dimer by MS and NMR. Analgesic effects were measured by acetic acid writhing and hot‐plate test in mice. The resveratrol dimer has the stronger analgesic effects than monomer, and drug combination of the dimer and cobra neurotoxin enhances and prolongs analgesic effects, suggesting the synergistic action. Simulation of molecular interaction reveals that the dimer spontaneously binds to cobra neurotoxin and makes a complex substance. The dimer can interact with cyclooxygenase‐2, μ receptor and nicotine receptor, the synergistic analgesic effects of the complex are attributed to its multiple targets role. The combination of resveratrol dimer and cobra neurotoxin may make up for their deficiencies in analgesic effects, and has prospects in clinical use.     

Hofmeister effects in enzymatic activity: weak and strong electrolyte influences on the activity of Candida rugosa lipase

The effects of weak and strong electrolytes on the enzymatic activity of Candida rugosa lipase are explored. Weak electrolytes, used as buffers, set the pH, while strong electrolytes regulate the ionic strength. The interplay between pH and ionic strength has been assumed to be the determinant of enzymatic activity. In experiments that probe activities by varying these parameters, there has been little attention focused on the role of specific electrolyte effects. Here we show that both buffers and the choice of background electrolyte ion strongly affect the enzymatic activity of Candida rugosa lipase. The effects here shown are dramatic at high salt concentration; indeed, a 2 M concentration of NaSCN is able to fully inactivate the lipase. By contrast, Na2SO4 acts generally as an activator, whereas NaCl shows a quasi-neutral behavior. Such specific ion effects are well-known and are classified among the "Hofmeister effects". However, there has been little awareness of them, or of their potential for optimization of activities in the enzyme community. Rather than the effects per se, the focus here is on their origin. New insights into mechanism are proposed.     

On the theory of birefringence in magnetic fluids

The influence of homogeneous correlations between the positions and orientations of ferroparticles on the effect of light birefringence in magnetic fluids has been studied. It has been demonstrated that, for typical magnetic fluids, the optical effects associated with the homogeneous correlations can be stronger than the effects caused by elongated primary aggregates formed at the stage of ferrofluid synthesis, as well as heterogeneous chains resulting from magnetic attraction between the largest particles of a magnetic fluid.     

Photochemistry of N-acylimino-isoquinolinium and -quinolinium betaines

The photochemical behavior of N-acyliminoisoquinolinium and -quinolinium betaines has been investigated. In contrast to pyridinium betaines, the principal course of reaction is the 1,2-migration of N-acylamino groups. Substituent effects as well as solvent effects are observed. The results are rationalized in terms of diaziridine intermediates.     

Visualizing electron correlation by means of ab initio scanning tunneling spectroscopy images of single molecules

Scanning tunneling microscopy (STM) has been a fundamental tool to characterize many-body effects in condensed matter systems, from extended solids to quantum dots. STM of molecules decoupled from the supporting conductive substrate has the potential to extend STM characterization of many-body effects to the molecular world as well. In this paper, we describe a many-body tunneling theory for molecules decoupled from the STM substrate, and we report on the use of standard quantum chemical methods to calculate the quantities necessary to provide the "correlated" STM molecular image. The developed approach has been applied to 18 different molecules to explore the effects of their chemical nature and of their substituents, as well as to verify the possible contribution by transition metal centers. Whereas the bulk of calculations has been performed with the configuration interaction method with single and double excitations (CISD), because of the computational cost some tests have been also performed with the more accurate coupled cluster with single and double excitations (CCSD) method to quantify the importance of the computational level on many-body STM images. We have found that correlation induces a remarkable squeezing of the images, and that correlated images are not derived from Hartree-Fock HOMO or LUMO alone, but include contributions from other orbitals as well. Although correlation effects are too small to be resolved by present STM experiments for the studied molecules, our results provide hints for seeking out other species with larger, and possibly experimentally detectable, correlation effects.     

Hyperconjugation as it affects conformational analysis

A primer for the qualitative identification and quantitative analysis of hyperconjugative delocalization is presented. The particular focus is upon the influence of hyperconjugation as it affects conformational analysis. Computational methodologies are illustrated within the context of several diverse molecular systems: anomeric and reverse anomeric effects in 2-tetrahydropyranosylammonium, generalized anomeric effects in phosphorus-stabilized carbanions, and hyperconjugative effects in phosphorus- and silicon-based trigonal bipyramids. Hyperconjugation is shown to compete with apicophilicity in the final examples. Although the latter influence has long been accounted for in traditional conformational analysis of trigonal bipyramidal systems, the former has been less appreciated.     

Yolk-shell gold nanoparticles as model materials for support-effect studies in heterogeneous catalysis: Au, @C and Au, @ZrO2 for CO oxidation as an example

The use of nanostructured yolk-shell materials offers a way to discriminate support and particle-size effects for mechanistic studies in heterogeneous catalysis. Herein, gold yolk-shell materials have been synthesized and used as model catalysts for the investigation of support effects in CO oxidation. Carbon has been selected as catalytically inert support to study the intrinsic activity of the gold nanoparticles, and for comparison, zirconia has been used as oxidic support. Au, @C materials have been synthesized through nanocasting using two different nonporous-core@mesoporous-shell exotemplates: Au@SiO(2)@ZrO(2) and Au@SiO(2)@m-SiO(2). The catalytic activity of Au, @C with a gold core of about 14 nm has been evaluated and compared with Au, @ZrO(2) of the same gold core size. The strong positive effect of metal oxide as support material on the activity of gold has been proved. Additionally, size effects were investigated using carbon as support to determine only the contribution of the nanoparticle size on the catalytic activity of gold. Therefore, Au, @C with a gold core of about 7 nm was studied showing a less pronounced positive effect on the activity than the metal oxide support effect.     

The role of particles in stabilising foams and emulsions

The use of particles as foam and emulsion stabilising species, with or without surfactants, has received great interest in recent years. The majority of work has studied the effects of particles as stabilisers in emulsion systems, but recent successes has widened consideration into foams, where industries such as flotation and food processing have encountered the effects of particle stabilisation for many years. This review seeks to clarify studies into emulsions, highlighting new research in this area, and relate similarities and differences to foam systems. Past research has focused on defining the interaction mechanisms of stability, such as principles of attachment energies, particle-particle forces at the interface and changes to the interfilm, with a view to ascertain conditions giving optimum stability. Studied conditions include effects of particle contact angle, aggregation formations, concentration, size and interactions of other species (i.e. surfactant). Mechanisms can be complex, but overall the principle of particles creating a steric barrier to coalescence, is a straitforward basis of interaction. Much research in emulsions can be applied to foam systems, however evidence would suggest foam systems are under a number of additional constraints, and the stability 'window' for particles is smaller, in terms of size and contact angle ranges. Also, because of increased density differences and interfilm perturbations in foam systems, retardation of drainage is often as important to stability as inhibiting coalescence.     

Isotope effects in ice Ih: a path-integral simulation

Ice Ih has been studied by path-integral molecular dynamics simulations, using the effective q-TIP4P/F potential model for flexible water. This has allowed us to analyze finite-temperature quantum effects in this solid phase from 25 to 300 K at ambient pressure. Among these effects we find a negative thermal expansion of ice at low temperatures, which does not appear in classical molecular dynamics simulations. The compressibility derived from volume fluctuations gives results in line with experimental data. We have analyzed isotope effects in ice Ih by considering normal, heavy, and tritiated water. In particular, we studied the effect of changing the isotopic mass of hydrogen on the kinetic energy and atomic delocalization in the crystal as well as on structural properties such as interatomic distances and molar volume. For D(2)O ice Ih at 100 K we obtained a decrease in molar volume and intramolecular O-H distance of 0.6% and 0.4%, respectively, as compared to H(2)O ice.     

Therapeutic poly(amino acid)s as drug carriers for cancer therapy

As one of the top global health problems, the effective treatment of cancer is one of the most urgent clinical challenges. Currently, the main treatments for cancer include surgery, chemotherapy, radiotherapy, and gene therapy etc. Chemotherapy is one of the most commonly used treatments, however it has limitations such as highly toxic side effects and low drug utilization rate that limit its application. Gene therapy, as an emerging cancer treatment, has limitations such as drug instability, off-target effects and low internalization efficiency. Poly(amino acid)s carriers with good biocompatibility, degradability and multifunctionality as drug carriers have received much attention, as they can reduce the toxic side effects of chemotherapy, improve drug utilization, and enhance the internalization efficiency and utilization of gene drugs. However, little attention has been paid to the nature of the carriers themselves. This paper reviews the immunomodulatory, anti-inflammatory, antioxidant, internalization-promoting and apoptosis-promoting functions of poly(amino acid)s drug carriers in tumor therapy to provide a theoretical basis for different carrier-drug-adapted synergistic therapies.