胶体金试纸检测保健食品中违法添加苯二氮类化合物的样品前处理方法研究

目的建立样品前处理方法,通过苯二氮胶体金试纸,实现对保健食品中违法添加苯二氮类化合物的样品进行快速检测。方法结合胶体金试纸的特性,对提取溶剂、提取时间、稀释体积等进行考察。结果筛选出最佳的样品前处理方法。结论该方法简便、准确,可作为保健食品中违法添加苯二氮类化合物样品的筛查方法。     

90例苯暴露者T淋巴细胞核仁组成区嗜银蛋白检测

目的检测苯暴露者外周血T淋巴细胞核仁组成区嗜银蛋白（Ag-NORs）,评价其作为苯暴露者早期的效应生物标志物的价值。方法采用KL型肿瘤免疫图像分析系统及配套试剂分析接触苯的高暴露者、低暴露者和对照者Ag-NORs区面积与细胞核仁区的百分比（I.S%）。结果 I.S%在高暴露者组为（6.2±0.7）,低暴露组为（7.5±0.8）,正常对照组为（7.6±0.7）,3组差异有统计学意义（F=2.36,P=0.013）,其中高暴露组低于低暴露组和对照组,低暴露组与对照组比较差异无统计学意义（P〉0.05）。结论 Ag-NORs检测能反映个体的苯接触水平,对职业健康检查早期筛查易感人群有一定的意义。     

纳米银的抗菌特性及其在医学中的应用

纳米银是利用现代纳米技术制造的新一代抗菌材料,因其具有优异的抗菌杀菌活性及在伤口修复方面的积极作用,在医学生物学领域获得了广泛应用.目前已有一些纳米银产品应用于临床,如纳米银抗菌凝胶、纳米银敷料、纳米银心血管支架、纳米银导管、纳米银骨水泥等.近年来的研究表明,纳米银的长效、广谱、强效的抗菌活性源于其对微生物复杂而特异的抗菌机制.尽管纳米银不会使病菌产生耐药性,是人们期望中的理想抗菌材料,但研究人员对其毒性机制依然不甚了解.本文就纳米银的合成、抗菌机制、毒性及在医学中的应用做了简要总结和展望.     

银纳米颗粒对神经元的毒性研究

目的 研究不同浓度的银纳米颗粒对神经元毒性的剂量-效应关系,探索银纳米颗粒对神经元的毒性机理.方法 首先培养一种活性好、生长状态优良的原代神经元,将不同浓度（2.5～500μg/mL）的银纳米颗粒加入神经元中作用24h后,通过MTT法计算细胞增殖率,并分析不同浓度的银纳米颗粒对神经元毒性的剂量-效应关系.结果 在25～250μg/mL范围内,细胞数量与形态呈现不同的变化,银纳米颗粒浓度与细胞增殖率呈负相关.结论 在25～250μg/mL的浓度范围内,银纳米颗粒对神经元细胞的毒性呈剂量-效应关系.     

Nanocomposites Based on Luminescent Colloidal Nanocrystals and Polymeric Ionic Liquids towards Optoelectronic Applications

Polymeric ionic liquids (PILs) are an interesting class of polyelectrolytes, merging peculiar physical-chemical features of ionic liquids with the flexibility, mechanical stability and processability typical of polymers. The combination of PILs with colloidal semiconducting nanocrystals leads to novel nanocomposite materials with high potential for batteries and solar cells. We report the synthesis and properties of a hybrid nanocomposite made of colloidal luminescent CdSe nanocrystals incorporated in a novel ex situ synthesized imidazolium-based PIL, namely, either a poly(N-vinyl-3-butylimidazolium hexafluorophosphate) or a homologous PIL functionalized with a thiol end-group exhibiting a chemical affinity with the nanocrystal surface. A capping exchange procedure has been implemented for replacing the pristine organic capping molecules of the colloidal CdSe nanocrystals with inorganic chalcogenide ions, aiming to disperse the nano-objects in the PILs, by using a common polar solvent. The as-prepared nanocomposites have been studied by TEM investigation, UV-Vis, steady-state and time resolved photoluminescence spectroscopy for elucidating the effects of the PIL functionalization on the morphological and optical properties of the nanocomposites.     

A silver enhanced and sensitive strip sensor for Cadmium detection

In this study, an enhanced test strip, based on a monoclonal antibody for the cadmium-ethylenediaminetetraacetic acid (EDTA) complex, but not metal-free EDTA, has been developed. This colorimetric sensor was sensitive and specific for the detection of cadmium in aqueous samples containing excess EDTA. Through a process of silver enhancement, the visual detection limit for Cd(II) was 5 µg/L under optimised conditions and the limit of detection for semi-quantitative detection could be as low as 0.35 µg/L by using a scanning reader. The calibration curve showed that the colour intensity decreased as the Cd(II) concentration increased in the range of 0.5–5 µg/L. The other metal ions did not interfere with the determination of Cd(II). The recoveries of drinking water samples were from 98 to 108%. Consequently, the assay could be employed as a potential on-site screening tool for the detection of Cd(II) in water samples.     

Histochemical and ultrastructural studies on pancreatic A cells. Evidence for glucagon and non-glucagon components of the α granule

Summary Glucagon-storing cells were detected in the pancreatic islets of horse, guinea pig, rabbit, rat, dog and man by means of indirect immuno-histochemical procedures using fluorescein or peroxidase as markers of antiglucagon sera. By subsequently staining horse islets with selective staining techniques for A, B or D cells, it was directly ascertained that only A cells reacted to antiglucagon sera. A comparison of methods known to stain a granules with immuno-histochemical methods, as well asin vitro experiments on natural and synthetic glucagon, showed that the xanthydrol method, and perhaps also theo-phthalaldehyde method, should be regarded as specific histochemical tests for glucagon whereas the HCl-basic dye technique and phosphotungstic haematein should be considered as unspecific glucagon-staining methods,and Grimelius' silver as a method likely to be unrelated to glucagon. In ultrastructural investigations on the human pancreas, the core of the a granule heavily reacted to phosphotungstic acid and peroxidase-marked antiglucagon antibodies, while being unreactive to Grimelius' silver; conversely, the peripheral halo of the granule heavily reacted to Grimelius' silver, while being poorly reactive or unreactive to phosphotungstic acid and anti-glucagon antibodies. Thus, both light and electron microscopy findings point to a structural and chemical hetereogeneity of the granule.

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Histochemische und ultrastrukturelle Untersuchungen über die A Zellen der Bauchspeicheldrüse. Nachweis von Glucagon und nicht-Glucagon Anteilen des -Granulums

Zusammenfassung Die Glucagon enthaltenden Zellen werden in der Bauchspeicheldrüse von Pferd, Meerschweinchen, Kaninchen, Ratte, Hund und Mensch durch immunhistochemische, indirekte Techniken mit Fluorescein-oder Peroxidase-Markierung von Anti-GlucagonAntikörpern lokalisiert. Durch aufeinanderfolgende Färbungen der Langerhansschen Inseln von Pferden mit spezifischen für die A, B und D Zellen histologischen Methoden, wurde bewiesen, daß nur die A Zellen mit AntiGlucagon-Antikörpern reagierten. Eine Gegenüberstellung der für die Färbung des-Granulums bekannten Methoden, mit den immunhistochemischen Methoden, und den alsin vitro Untersuchungen über synthetisches und natürliches Glucagon, haben bewiesen, daß die Xanthydrol-Methode, und vielleicht auch dieo-Phtalaldehyd Methode, für das Glucagon spezifische Methoden darstellen, während die HCl-basischen Farbstoffe und die Phosphorwolframsäure-Hämatin Methoden, als unspezifische Färbemethoden für das Glucagon angesehen werden müssen; die Silbermethode nach Grimelius scheint nicht zum Glucagon in Beziehung zu stehen. In ultrastrukturellen Untersuchungen über die menschliche Bauchspeicheldrüse, reagierte das Zentrum (core) des Granulums stark auf die Phosphorwolframsäure und auf die mit Peroxidase markierten Anti-Glucagon-Antikörper, dagegen reagierte es nicht mit der Silbermethode nach Grimelius. Andererseits reagierte der periphere Hof des Granulums wenig, oder überhaupt nicht mit der Phosphorwolframsäure und den Anti-Glucagon-Antikörpern. Daher zeigen die Ergebnisse von Licht-und Elektronenmikroskopie eine chemische und strukturelle Ungleichartigkeit des-Granulums.

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Etudes histochimiques et ultrastructurales des cellules pancréatiques A. Preuves de la présence de constituants glucagoniques et non-glucagoniques dans les granules

Résumé Des cellules stockant du glucagon ont été détectées dans les îlots pancréatiques du cheval, du cobaye, du lapin, du rat, du chien et de l'homme au moyen de procédés immuno-histochimiques indirects utilisant la fluorescéine ou la peroxydase comme marqueurs des sérums anti-glucagon. En colorant les îlots des chevaux avec des techniques de coloration sélectives pour les cellules A, B ou D, il a été directement prouvé que seules les cellules A réagissent aux sérums anti-glucagon. Une comparaison entre les méthodes connues pour colorer les granules et les méthodes immuno-histochimiques, ainsi que les expériencesin vitro sur le glucagon naturel et synthétique, ont montré que la méthode au xanthydrol et peut-être également la méthode à l'o-phtalaldéhyde, doivent être considérées comme des tests histochimiques spécifiques pour le glucagon; par contre la technique à l'HCl-colorant basique et l'hématéine phosphotungstique doivent être considérées comme des méthodes de coloration non spécifiques pour le glucagon, et la méthode à l'argent de Grimelius probablement comme ne concernant pas le glucagon. Au cours d'investigations ultrastructurales sur le pancréas humain, le centre des granules réagissait fortement à l'acide phosphotungstique et aux anticorps anti-glucagon marqués à la peroxydase, alors qu'il ne réagissait pas à l'argent de Grimelius; inversement le halo périphérique des granules réagissait fortement à l'argent de Grimelius, et réagissait peu ou pas à l'acide phosphotungstique et aux anticorps anti-glucagon. Ainsi, les résultats à la fois de microscopie optique et électronique indiquent une hétérogénéité structurale et chimique des granules.

     

Clinical evaluation of diamine silver fluoride/potassium iodide as a dentine desensitizing agent. A pilot study

Background: The aim of the present study was to compare the efficacy of an experimental diamine silver fluoride/potassium iodide product with an oxalic acid‐based preparation in reducing dentine hypersensitivity. Methods: The study was conducted as a double‐blind, randomized clinical trial. A total of 19 subjects with dentine hypersensitivity on both sides of their upper arch were selected. The most sensitive tooth in each quadrant was identified and received a cold stimulus. The response was recorded on a visual analogue scale (VAS). The tooth thus selected was treated with one of the treatment agents. One week later the level of dentine sensitivity was assessed. Participants were also asked for their subjective assessment of treatment effects. Results: The mean difference between VAS at baseline and seven days for teeth treated with diamine silver fluoride/potassium iodide was greater than that for teeth treated with the oxalic acid‐based preparation (p = 0.0134). The subjects’ subjective assessment of changes in dentine hypersensitivity indicated that more obtained relief with the diamine silver fluoride/potassium iodide treatment (p = 0.0129). Conclusions: It was concluded that an experimental diamine silver fluoride/potassium iodide product has potential as a treatment for dentine hypersensitivity.