盲目补锌危害多(一)

锌是人体中不可缺少的微量元素之一。锌在体内约含有2．5g，用这些锌可制作4枚图钉或5枚回形针，可谓是真正的微量元素。     

白血病骨髓移植患者口腔黏膜病与微量元素锌的关系

为研究白血病骨髓移植患者全血微量元素锌与口腔黏膜病的关系，用原子吸收光谱法检测了正常对照组与白血病骨髓移患者预处理前及移植后骨髓空虚期全血微量元素锌的含量，并观察了白血病骨髓移植患者空黏膜病变情况。结果表明，正常对照组全血锌浓度与白血病骨髓移植患者预处理前全血锌浓度比较，差异无显著性（P＞0．05），而预处理前全血锌浓度与骨髓空虚期全血锌浓度有显著性差异（P＜0．01），白血病缓解后（预处理前）血锌接受正常水平，无口腔溃疡发生，而白血病骨髓移植患者处理后骨髓空虚期全血锌含量显著降低，并出现不同程度的口腔黏膜病变，说明预处理影响微量元素锌的代谢，微量元素锌的减少与白血病骨髓移植患者移植患者口腔黏膜病的发生有关。     

微量元素对老年人健康的作用与危害

介绍了微量元素的生理功能，微量元素与衰老，长寿和老年人冠心病，高血压，脑血管疾病，肿瘤，糖尿病等五种常见病的关系。还特别介绍了锌对人类健康的作用和铅对人类健康的危害。老年人体内有益的微量元素，如铁，锌，锰，铬，硒等比较缺乏，相反镍，铅，铝等有害的微量元素比较高。长寿老人头发中有益微量元素锰，钴，硒，铜，锌，铬等均有较高水平。人要长寿，必须维持体内微量元素的水平，微量元素过低或者过高应及时通过食疗或药物治疗进行调节。     

病毒性肝炎、肝硬化与微量元素

（1）病毒性肝炎与微量元素锌、硒、铜有关：张冠群等测定了128例乙肝患者血清微量元素含量。结果显示，慢性乙肝患者血清锌、铜、铁含量低于常人，急性肝炎患者血清锌铜铁与常人无差异。任仲轩测定了47例老年慢性病毒性肝炎患者与45例非老年患者血清微量元素含量。结果显示，两组锌、铜、硒含量皆低于健康对照。王晋升等测定了122例急慢性肝炎患者血清微量元素含量。     

金蒲抑瘤片在鼻咽癌的临床应用研究

为探讨鼻咽癌患者放疗期间合并应用金蒲抑瘤片治疗对细胞免疫功能及血中微量元素硒、锌、铜的影响，经病理证实鼻咽癌患者58例，随机分为放疗服药组30例和单纯放疗组28例。两组放疗前后抽静脉血测定T细胞亚群（CD3＋，CD4＋，CD8＋，CD4＋／CD8＋），血中微量元素硒，锌，铜并与30例健康者（正常对照组）进行比较。结果表明，鼻咽癌患者血中微量元素硒，锌，铜及CD3＋，CD4＋，CD4＋／CD8＋显著低于健康人，放疗期间合并应用金蒲抑瘤片治疗后血中微量元素硒，锌，铜及CD3＋，CD4＋，CD4＋／CD8＋较服药前显著升高。提示鼻咽癌患者细胞免疫功能低下，血中微量元素硒，锌，铜显著低于健康人。金蒲抑瘤片能提高鼻咽癌患者因中微量元素硒，锌，铜含量，使低下的细胞免疫功能迅速恢复。     

轮状病毒感染性腹泻患儿的微量元素锌检测结果分析

目的：检测轮状病毒感染性腹泻患儿的全血微量元素锌的水平,探讨轮状病毒感染性腹泻患儿全血微量元素锌的变化。方法对186例轮状病毒感染性腹泻患儿和675例健康对照组儿童进行全血微量元素锌测定。结果轮状病毒感染性腹泻患儿全血微量元素锌含量明显低于健康对照组儿童,差异有统计学意义（ P＜0.05）。结论轮状病毒感染性腹泻患儿全血微量元素锌水平明显下降,需要及时补充微量元素锌。     

健骨胶囊中微量元素对实验大鼠股骨的影响

通过对健骨胶囊及实验大鼠股骨中的微量元素铜、锌、铁、锰的分析，阐述了健骨胶囊中微量元素对实验大鼠股骨中的微量元素铜、锌、铁、锰的影响以及骨质疏松症的改善，具有重要的营养学、药理功效学作用。     

锌与健康

为探讨微量元素锌与人体健康的关系，从锌的食物来源及影响吸收利用因素、锌的生物学作用，锌含量及发锌值，锌缺乏的临床表现等方面进行了综述。     

中药微量元素锌,铜,铁,锰的研究

简介了微量元素的概念及进行中药微量元素研究的重要意义，回顾了近十多年来中药微量元素锌，铜，铁和锰的研究概况，引用参考文献３３篇。     

石英粉尘肺损伤大鼠肺脏、脾脏微量元素锌、铜、镁含量的测定

为探讨石英粉尘（SiO2) 对大鼠肺脏及脾脏微量元素锌，铜，镁含量的影响作用，将雄性Wistar大鼠随机分为两组，实验结束后分别测定大鼠肺脏和脾脏微量元素锌，铜，镁含量。结果表明，SiO2组与对照组比较，脾脏，肺脏锌，镁含量下降，铜含量上升（P＜0．05）。提示SiO2能使肺脏受到损伤，并引起机体微量元素失衡，使脾脏亦受到损伤，造成机体免疫功能下降。     

Elution mechanism of polypeptides in reversed-phase liquid chromatography based on the critical threshold of organic solvent to induce abrupt change in adsorption capacity to the column packing

Adsorption capacity of polypeptides to the column packing in a solution containing multiple organic solvents was found to be expressed by means of an fn value, which is the sum of the ratios of the content of each organic solvent in the solution to the critical content of each organic solvent to cause abrupt change in the adsorption capacity, and to change abruptly at the point where the fn value becomes 1. Additionally, our results indicate that each polypeptide is eluted by the eluent containing a specific organic solvent content regardless of gradient elution rate in reversed-phase liquid chromatography, and that total organic solvent content in the eluent containing polypeptides is equal to the critical content. Considering the power law relationship between the retention times and the gradient elution rates, our results suggest that the elution of each polypeptide in reversed-phase liquid chromatography is mainly controlled by abrupt change in the adsorption capacity induced by change in the organic solvent content of the eluent during a gradient elution process, and that the abrupt change repeats across the critical threshold while a polypeptide moves through the column, and as a result, each polypeptide is concentrated in the eluent with the critical threshold.     

聚并苯纳米颗粒与聚丙烯复合制备新型抗静电阻燃材料

用聚并苯纳米颗粒作为新型导电填料代替导电炭黑和石墨等, 制备出具有抗静电阻燃性能的纳米聚并苯/聚丙烯复合材料. 测定了复合材料的渗流转变区, 讨论了纳米聚并苯含量对复合材料体积电阻率和表面电阻率的影响. 实验结果表明, 所制备复合材料的渗流转变发生在纳米聚并苯质量分数为16.7%-28.6%范围内, 当纳米聚并苯含量为28.6%时, 体积电阻率下降至2.09×107 Ω·cm. 另外, 阻燃性能研究结果表明, 当纳米聚并苯质量分数为23.1%时, 复合材料在空气中可以自熄, 因而可应用于矿井中抗静电阻燃塑料管道.     

NiO的单层分散态及其载体效应

The NiO dispersion phase on three different supports have been studied by EXAFS in combination with XRD quantitative phase analysis. The result of XRD shows the threshold of NiO/γ-Al_2O_3 system is larger than that of NiO/TiO_2 system and the threshold of NiO/SiO_2 system is the least. From the FT functions of EXAFS for samples we can find that in NiO/γ-Al_2O_3 system a part of Ni changes its coordination polyhedra into tetrahedra, the Ni-Ni coordination peaks reduce markedly with the decrease of NiO content in samples. The result of EXAFS fitting and phase isolation shows Ni-Ni coordination number increases with the increase of NiO content in samples of NiO/γ-Al_2O_3 system and reaches a maximum value of 4.0 and remains constant when NiO content reaches the threshold obtained by XRD. It shows the structure of NiO dispersion phase is in better agreement with the NiO monolayer dispersion model than any other models.
In FT functions of EXAFS for samples at thresholds of two systems the Ni-Ni coordination peaks of NiO/TiO_2 system is much lower than those of NiO/γ-Al_2O_3 system. But they are similar when their NiO contents both close to the threshold of NiO/TiO_2 system. It shows that though the dispersion capacity of NiO in NiO/TiO_2 system is less than that in NiO/γ-Al_2O_3 system its dispersion performance is better.
In NiO/SiO_2 system the coordination peaks are similar to those of pure NiO and the Ni-Ni coordination number approaches 12 of the pure NiO. It shows it is difficult for NiO to disperse on the surface of SiO_2. In fact, for the NiO/SiO_2 system the threshold obtained by XRD is beyond the experiment accuracy so there is no threshold for this system.
Therefore above facts indicate that dispersion threshold and reducing of metal-metal coordination number of the dispersion phase is a quite characteristic feature of monolayer dispersion state.     

Features of the melt flow of polyethylene and boron oxide oligomer blends

The features of melt flow of LDPE and boron oxide oligomer blends during extrusion mixing are investigated. It is established that the extruder-wall pressure and the torque of the screw decrease monotonically with an increase in the boron oxide oligomer content up to 25 vol %. Exceeding this concentration threshold leads to a several-fold stepwise fall in of the mentioned characteristics. This result is explained within the concepts about spontaneous restructuring of the blend accompanied by an increase of the specific surface of phases and by slipping at the interface of the blend components that is caused by the planar structure of the boron oxide oligomer molecules.     

Effect of Graphene Additions on the NCP Initiation Threshold in Spectrum-Selective Excitation

The effect of graphene additions on the initiation threshold of (5-nitrotetrazolato-N²)pentamminecobalt(III) perchlorate in excitation in the overtone of the vibration mode (λ = 1554 nm) was studied. The dependence of the initiation threshold power on the graphene content passes through a minimum at 3 wt % graphene. In this case, the threshold power decreases by a factor of ～10. The minimum obtained value of the threshold power density is 0.15 W mm^?2. The dependence of the initiation threshold power on the content of the absorbing impurity was considered theoretically. Based on the data obtained, the use of erbium lasers, including fiber lasers operating at a wavelength of 1.55 μm, for initiation of energetic complexes based on cobalt aminates was suggested.

     

Study of the critical points in lobenzarit disodium hydrophilic matrices for controlled drug delivery

Percolation theory is a multidisciplinary theory that studies chaotic systems. It has been applied in the pharmaceutical field since 1987. The application of this theory to study the release and hydration rate of hydrophilic matrices allowed for first time to explain the changes in release and hydration kinetic of swellable matrices type controlled delivery systems. The objective of the present paper is to estimate the percolation threshold of HPMC K4M in matrices of lobenzarit disodium and to apply the obtained result to the design of hydrophilic matrices for the controlled delivery of this drug. The materials used to prepare the tablets were Lobenzarit disodium (LBD) and HPMC of viscosity grade K4M. The drug mean particle size was 42+/-0.61 mum and the polymer was sieved and 150-200 microm granulometric fraction was selected. The formulations studied were prepared with different excipient contents in the range of 10-80% w/w. Dissolution studies were carried out using the paddle method and the water uptake measurements were performed using a modified Enslin apparatus. In order to estimate the percolation threshold, the behaviour of the kinetic parameters with respect to the volumetric fraction of each component at time zero, was studied. According to percolation theory, the critical points observed in dissolution and water uptake studies are attributed to the existence of an excipient percolation threshold. This threshold was situated between (18.58 to 24.33% v/v of HPMC). Therefore, the LBD-HPMC K4M matrices with a relative HPMC particle size of should be formulated with an excipient content above 24.33% v/v of HPMC, to obtain a control of the drug release from these systems.     

负载型纳米ZrO2-Al2O3复合载体中ZrO2的负载量对Ni基催化剂性能的影响

采用真空浸渍法在负载型纳米ZrO2-Al2O3复合载体上负载NiO,并用X射线衍射考察了NiO在复合载体上的分散周值.结果表明,该分散阈值与ZrO2-Al2O3复合载体中ZrO2的负载量有关,当ZrO2的负载量为0.60 g/g时,NiO的分散阈值达到最高值0.315 g/g.热重-微分热重和程序升温脱附结果表明,NiO在不同ZrO2负载量的复合载体表面形成不同的相互作用和分布状态,复合载体中ZrO2的负载量影响催化剂表面活性中心的种类和对CO2的吸附.同时考察了不同ZrO2负载量的复合载体Ni基催化剂在CO2重整CH4反应中的活性和稳定性.     

Stabilization of Nanostructured Zeolite Particles: The Effect of Sodium Polyacrylate on the Disaggregation Kinetics and Threshold

The influence of sodium polyacrylate on the disaggregation kinetics and threshold of conglomerates of a natural agromineral, zeolite, under ultrasonic dispersion has been studied. It has been demonstrated that the use of sodium polyacrylate as a stabilizing additive has resulted in the reduction of the zeolite particle size, the increase in the content of isolated fractions, and significant decrease in the ultrasonic treatment duration. When the zeolite was dispersed with sodium polyacrylate, the particles achieved an average size of 750.0 nm after the first minute of cavitation treatment, while the dispersion of the agromineral without the additive required a 5-min treatment to achieve the same result. The use of sodium polyacrylate increased the stabilized state period of zeolite particles to half a year.     

Formation of mesoscopic water networks in aqueous systems

Formation of the macroscopically-infinite hydrogen-bonded water network in various aqueous systems occurs via 3D percolation transition when the probability of finding a spanning water cluster exceeds 95%. As a result, in a wide interval of water content below the percolation threshold, rarefied quasi-2D water networks span over the mesoscopic length scale. Formation and topology of spanning water networks, which affect various properties of aqueous systems, can be described within the framework of the percolation theory.     

Highly sensitive and quantitative analysis of polyeptides using a new gradient system based on an abrupt change in adsorption of polypeptide to the reversed-phase column packing

During a study of 100 microL aliquots of urocortin containing various acetonitrile contents, we hypothesized that a change in the acetonitrile content in the solution across a specific content of acetonitrile (critical threshold) causes an abrupt change in adsorption capacity to the column packing. Circular dichroism measurements suggest that the conformational change induced by acetonitrile in the solution causes the abrupt change in adsorption capacity, and this solvent-induced conformational change is reversible across the critical threshold. This hypothesis can apply to various polypeptides with molecular weights range from 1007 to 6789 and to other organic solvents. A new gradient system utilizing the instant recovery of the adsorption capacity across the critical threshold was designed, and applied to the analysis of a 100 microL aliquot of various polypeptide solutions. The results suggest that use of a solution containing organic solvents more than the critical threshold allows successful dilution of polypeptides up to picomolar concentration range without any loss due to its adsorption during handling procedures and loading onto the LC system, and that a new gradient system enables quantitative analysis of polypeptides at picomolar concentrations in such solutions.