基于恐伤肾的阿尔茨海默病肾虚证大鼠模型的建立与评价

目的构建和评价D-半乳糖和三氯化铝结合夹尾(恐吓)建立阿尔茨海默病肾虚证病证结合大鼠模型。方法随机将48只SD大鼠分为对照组、模型组、夹尾组和肾气丸组,每组12只。对照组给予0.9%NaCl溶液灌胃,其余组均采用D-半乳糖及三氯化铝造模,持续8周;夹尾组和肾气丸组从第5周开始,在造模的同时用夹尾(恐吓)法建立肾虚证病证结合模型,肾气丸组同时给予金匮肾气丸10g/kg灌胃。每2周观察记录1次大鼠的症状、体征变化,第8周末进行水迷宫测试。测试结束后,腹主动脉采血,离心收集血清检测下丘脑-垂体系统生化指标。取大鼠大脑,用HE染色和免疫荧光组化法对大脑的海马组织进行检测。结果夹尾组表现为精神亢奋、躁动,大便色黑干硬,毛色发暗枯槁等,造模第6周和第8周症状、体征量化评分均明显高于其他组(P均<0.05);对照组、模型组症状、体征相似,实验过程中各时间点量化评分比较差异均无统计学意义(P均>0.05)。水迷宫测试显示模型组、夹尾组、肾气丸组与对照组相比潜伏期均明显延长(P均<0.05),穿越平台次数明显减少(P均<0.05),而夹尾组比模型组出现较早。海马组织HE染色和免疫荧光组化显示模型组、夹尾组比对照组出现较多神经元细胞死亡和CHAT阳性神经元减少,而夹尾组较为严重,肾气丸组则有改善。下丘脑-垂体-肾上腺轴生化指标血清皮质醇水平模型组明显高于对照组、夹尾组、肾气丸组(P均<0.05),夹尾组明显低于肾气丸组和对照组(P均<0.05),肾气丸组与对照组比较差异无统计学意义(P>0.05)。结论大鼠经D-半乳糖和三氯化铝结合夹尾(恐吓)建立阿尔茨海默病肾虚证是比较理想病证结合模型,可能皮质醇下降是阿尔茨海默病肾虚证证候客观化评价指标之一。     

Gastrointestinal transit times in mice and humans measured with 27Al and 19F nuclear magnetic resonance.

Gastric emptying and gastrointestinal (GI) transit times in mice and humans were monitored noninvasively by using 27Al and 19F nuclear magnetic resonance (NMR). Al(3+) bound to ion-exchange resin and perfluorononane were administered orally as selective and specific markers for the stomach and the entire GI tract, respectively. 27Al- and 19F-MR spectroscopy (MRS) was employed to follow quantitatively boli of the mixed markers in awake, fed mice over a period of 48 hr. The selectivity of the markers was confirmed by whole-body 1H-, 27Al-, and 19F-MRI of anesthetized mice. Gastric emptying in humans was also monitored with 27Al-MRS of aluminum-loaded ion exchange resin. GI transit was assessed by 19F projection imaging of pharmaceutical capsules tagged with perfluorononane. Quantitative analysis of the MR data revealed that gastric emptying in humans proceeded linearly, whereas in mice an exponential decay was observed. This difference is explained by the respective feeding patterns of humans and mice. Humans usually achieve nearly complete gastric emptying before each meal. In contrast, very short delays between successive food intakes in small animals result in successive dilution of the stomach contents. For stomach emptying in mice the exponential decay constant was 74 min, whereas the half-time of the linear gastric emptying in humans was 30 min.     

The stimulatory effect of clonidine on locus coeruleus neurons of rats with inactivated α2-adrenoceptors: involvement of imidazoline receptors located in the nucleus paragigantocellularis

Clonidine stimulates locus coeruleus neurons by an α₂-adrenoceptor-independent mechanism which probably involves imidazoline receptors. To study this effect, single-unit extracellular recordings in the locus coeruleus were performed in anaesthetised rats after complete, irreversible inactivation of α₂-adrenoceptors by the alkylating agent N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ) (6 mg/kg i.p.; 6 h before experiments). After this pretreatment, clonidine applied into the locus coeruleus failed to produce any change in the cell firing rate. However, clonidine applied intravenously (320–2560 μg/kg), or locally (0.5–2.0 μl of 0.02 M) into the nucleus paragigantocellularis, a major locus coeruleus afferent, stimulated locus coeruleus neurons (increasing the firing rate by approximately 90%). Electrical lesions of the nucleus paragigantocellularis greatly attenuated the clonidine induced stimulation of locus coeruleus neurons ipsilateral to the lesion when applied intravenously. Blood pressure which was recorded simultaneously with cell recording, remained unaffected after clonidine administration in EEDQ pretreated rats. These results indicate that the clonidine-induced stimulation of locus coeruleus neurons is an indirect effect mediated by imidazoline receptors located on paragigantocellularis neurons projecting to the locus coeruleus. Received: 12 August 1996 / Accepted: 13 October 1996     

Multiple interactions of aluminum with neurofilament subunits: Regulation by phosphate-dependent interactions between C-terminal extensions of the high and middle molecular weight subunits

Exposure of individual purified neurofilament (NF) proteins to AlCl₃ alters their electrophoretic properties in a time- and concentration-dependent manner, as visualized by their failure to migrate into SDS gels. Co-incubation of purified high (NF-H) and middle (NF-M) but not low (NF-L) molecular weight NF subunits prevents this AlCl₃-induced alteration in electrophoretic migration. This latter finding suggested that specific interactions between NF-H and NF-M other than filament formation influenced their interaction with AlCl₃. Co-incubation of the 160 kDa α-chymotryptic cleavage product of NF-H (corresponding to the highly phosphorylated C-terminal sidearm domain) with native NF-M prevented alteration in subunit electrophoretic migration by AlCl₃. By contrast, intact, dephosphorylated NF-H subunits were unable to prevent AlCl₃-induced alteration of native NF-M electrophoretic migration. Taken together, these findings suggest that phosphate-dependent interactions between the sidearm extensions of NF-H and NF-M diminish the ability of AlCl₃ to associate with either subunit in a manner that alters their electrophoretic migration. This interaction of NF-H and NF-M sidearms is SDS-sensitive, while AlCl₃-induced alteration in electrophoretic migration of individual subunits is SDS-resistant. Addition of SDS to mixtures of NF-H and NF-M subunits disrupted the protective effect, and promoted AlCl₃-induced alterations in subunit electrophoretic migration. These findings support and extend the current hypothesis that the ability of aluminum to interact with NF subunits is a function of subunit phosphorylation, assembly, and extent of neurofilament-neurofilament cross-linking. © 1994 Wiley-Liss, Inc.     

Controlled Molecular Release Using Nanoporous Alumina Capsules

The use of mechanically robust nanoporous alumina capsules, with highly uniform pores of 25 nm to 55 nm, for controled drug delivery is demonstrated. The nanoporous alumina capsules were fabricated by anodization of an aluminum tube, resulting in a highly uniform, large surface area, relatively inexpensive device suitable for biofiltration applications. Characterization of diffusion from the nanoporous capsules using fluorescein isothiocyanate and dextran conjugates of varying molecular weight, showed that molecular transport could be readily controlled by selection of capsule pore size. A branched membrane structure, with a stepwise change in pore size from large to small, is used to provide small pore-sized membranes with sufficient mechanical strength for handling.     

Neuropsychological deficit among elderly workers in aluminum production

A cross-sectional study was conducted at a Norwegian primary aluminum plant. All workers aged 61-66 years were offered early retirement benefits. Among the workers, 47 met the study criteria and 38 (81%), comprising 14 potroom workers, 8 foundry workers, and 16 controls, volunteered to participate. They were tested with a neuropsychological test battery. Workers in potrooms with Søderberg electrolytic cells were found to show signs of impairment of the nervous system. A test for tremor discriminated significantly between the potroom group and the controls. There was a suggestion of increased risk of impaired visuospatial organization and a tendency to a decline in psychomotor tempo in the potroom workers. We suggest that the above findings may be related to long-term occupational exposure in the potroom, and further to chronic low-dose exposure to aluminum. © 1994 Wiley-Liss, Inc.     

配酸的微机自动控制系统

介绍了利用ＰＣ，总线工控机构成的铝箔腐蚀用酸配酸系统的软硬件设计。该系统可以完成正极箔用酸、负极箔用酸及小酸配制的自动控制。系统具有良好的用户界面，并取得了明显的经济效益。     

Protective effect of human adipose-derived stem cells transplanted to fat grafts against high-power laser therapy mediated fat tissue damage

Introduction

High Power Laser therapy (HPLT) can damage tissues due to its high skin absorption and side effects. The objective of this study was to determine the protective effect of human adipose-derived stem cells (hADSCs) against HPLT-mediated fat tissue damage after fat grafts in an in vivo study.

Microstructural Evolution at Micro/Meso-Scale in an Ultrafine-Grained Pure Aluminum Processed by Equal-Channel Angular Pressing with Subsequent Annealing Treatment

Micro-forming with ultrafine-grained (UFG) materials is a promising direction for the fabrication of micro-electro-mechanical systems (MEMS) components due to the improved formability, good surface quality, and excellent mechanical properties it provides. In this paper, micro-compression tests were performed using UFG pure aluminum processed by equal-channel angular pressing (ECAP) with subsequent annealing treatment. Microstructural evolution was investigated by electron back-scattered diffraction (EBSD) and transmission electron microscopy (TEM). The results show that microstructural evolutions during compression tests at the micro/meso-scale in UFG pure Al are absolutely different from the coarse-grained (CG) materials. A lot of low-angle grain boundaries (LAGBs) and recrystallized fine grains are formed inside of the original large grains in CG pure aluminum after micro-compression. By contrast, ultrafine grains are kept with few sub-grain boundaries inside the grains in UFG pure aluminum, which are similar to the original microstructure before micro-compression. The surface roughness and coordinated deformation ability can be significantly improved with UFG pure aluminum, which demonstrates that the UFG materials have a strong potential application in micro/meso-forming.     

Wire Arc Additive Manufacturing of Al-Mg Alloy with the Addition of Scandium and Zirconium

The proposed paper considers the opportunity of expanding the application area of wire arc additive manufacturing (WAAM) method by means of increasing the strength properties of deposited material, due to the implementation of aluminum wire with the addition of scandium and zirconium. For the experimental research, the welding wire 1575 of the Al-Mg-Sc-Zr system containing 0.23% Sc and 0.19% Zr was selected. The optimal welding parameters, ensuring the defect-free formation of deposited material with low heat input, were used. Porosity level was estimated. The thermal state was estimated by finite element simulation. Simulated thermal state was verified by comparison with thermocouples data. Post-heat treatment parameters that lead to maximum strength with good plasticity were determined. The maximum yield strength (YS) of 268 MPa and ultimate strength (UTS) of 403 MPa were obtained, while the plasticity was determined at least 16.0% in all WAAM specimens.