大鼠前脑动脉的形态学研究

目的观察大鼠前脑动脉的分布、形态和结构,为进一步研究脑血管疾病提供依据。方法通过颈总动脉注射红色乳胶和多种染色方法对大鼠前脑动脉的大体形态和微细结构进行观察。结果大鼠脑基底动脉环完整,颈内动脉和基底动脉在前脑的主要分支有大脑前动脉、大脑中动脉和大脑后动脉。其中,大脑前动脉位于大脑纵裂底部,几何形态学指标稳定,镜下脑动脉管壁形态结构典型。结论大鼠前脑动脉大体形态学和微细结构与人端脑动脉相似,大脑前动脉由于其位置恒定和结构典型在研究脑血管改变方面具有一定价值。     

不育男性精浆果糖及精浆锌含量的研究

目的探讨不育男性精浆果糖含量及精浆锌含量与精子密度、活力及形态的关系。方法分析89例不育男性患者（不育组）、33例正常生育后男性（生育组）的精液样本,采用计算机辅助精液分析进行精子密度、活力参数检测,采用精子形态检测系统下人工修正方法进行精子形态分析,精浆果糖及精浆锌含量采用分光光度比色法测定。结果不育组精浆果糖及锌含量均显著低于生育组（P〈0.05）;精浆果糖含量异常组精子密度显著高于果糖含量正常组（P〈0.05）;精浆锌含量正常组精子活力高于异常组（P〈0.05）。结论精浆果糖含量与精子密度密切相关,精浆锌含量与精子活力密切相关,但二者与精子形态无关。     

Role of Silica Properties in the Polymerisation of Ethylene Using Supported Metallocene Catalysts

The role of certain morphological properties of different silica used as supports for metallocene catalysts was investigated in order to quantify their eventual influence on the kinetics of ethylene polymerisation in heptane slurry, as well as on the polymer properties. It was shown that there is no clear link between porosity and observed activity with some highly porous silica producing relatively inactive supported catalysts. It was further shown that within a batch of silica, the particle size had a significant impact on observed kinetics. While it appears that there is possibly some diffusion resistance encountered in the larger particles, it was also shown that prolonged contact between the support and the alkylating agent could increase reaction rates in the larger particles.

     

Electrochemically Induced RAFT Polymerization of Thermoresponsive Hydrogel Films: Impact on Film Thickness and Surface Morphology

Thin hydrogel films of the thermoresponsive polymer poly(N‐isopropylacrylamide) (pNIPAm) were prepared by electrochemically triggered reversible addition‐fragmentation chain transfer (RAFT) polymerization. Two different RAFT agents were employed, which work in either acidic or basic solution. In both cases, addition of RAFT agents had an influence on the thickness and the surface morphology of the films. At low concentration, the polymerization efficiency increased. At high concentration, the efficiency decreased at acidic pH, while it remained constant under basic conditions. Neither RAFT agent displayed electrochemical activity on its own, but they did modify the electrochemical behavior of the initiator. The addition of RAFT agent strongly enhances the homogeneity of the hydrogel surfaces, which presumably is due to a reduced amount of microgel formation.

     

Morphology of Novel PEAs Containing Two Consecutive Amide Bonds Randomly Distributed Along the Polyester Backbone

The morphology of a series of novel segmented PEAs with varying amide content was studied by a combination of DSC, SFM and proton solid state NMR. Semicrystalline polymers organised in a lamellar morphology were obtained for all amide contents. The results of different NMR experiments revealed that a three phase system composed of a rigid phase, an interface and a mobile amorphous phase is the most appropriate model to describe the morphology of these materials. The amount, the chain dynamics and the domain size of each phase were estimated and correlated with the amount of the amide fraction. Such morphological investigations help to understand the macroscopic properties of segmented PEAs for their applications as biomaterials.

     

The reversibility of sperm quality after discontinuing nandrolone decanoate in adult male rats

Aim： To investigate the reversibility of the effect of nandrolone decanoate （ND） on sperm parameters after discontinuing the drug. Methods： Three groups of rats received peanut oil （control）, low and high doses of ND for 14 weeks, respectively. Each group was divided into subgroups A and B, in which rats were killed 14 and 28 weeks after initiating the injection, respectively. Results： Sperm count and motile sperm fraction were decreased in the subgroups A and B that received low and high doses of ND in comparison with the controls A and B, respectively. The sperm count and motile sperm fraction increased in the subgroups B that received low and high doses of ND in comparison with their corresponding subgroups A. The number of normal morphology sperm was decreased significantly in subgroups A receiving low and high doses of ND in comparison with the control subgroup A. However, this parameter was not decreased in subgroups B receiving low and high doses in comparison with the control subgroup B. The normal sperm morphology did not show any significant differences in the subgroups B in comparison with their corresponding subgroups A. Conclusion： The 14-week injection of low and high doses of ND decreases sperm quality and quantity in rats. These parameters were improved after discontinuing ND, but not recovered completely even when they are left untreated for 14 weeks.     

Effect of different power parameters of Er,Cr:YSGG laser on human dentine

The aim of this work was to determine the optimal power setting of an Er,Cr:YSGG laser for cutting human dentine to produce a surface that remains suitable as a foundation on which to build and bond a dental restoration. The cutting efficiency and resulting microhardness of the dentine were evaluated for various laser power settings, and representative samples were examined by SEM. The microhardness of the dentine was significantly reduced by 30–50% (p < 0.05, paired t test) after laser irradiation, irrespective of the power setting used. The mean ablation efficiency increased in proportion to the power setting of the laser. Although the laser power setting did not affect the extent of reduction in microhardness, it did affect the microstructure of human dentine.     

Seminal plasma albumin: origin and relation to the male reproductive parameters

We wanted to investigate the origin of seminal plasma albumin and its relation to the male reproductive parameters. Semen samples from 916 men, under infertility assessment, were analysed according to guidelines of the World Health Organization. Seminal plasma constituents, i.e. albumin, markers of the epididymal (neutral alpha-glucosidase, NAG), prostatic (prostate-specific antigen, PSA, and zinc) and seminal vesicle function (fructose), as well as levels of reproductive hormones in plasma were measured. The sperm chromatin structure assay (SCSA) was applied on 267 of the 916 samples. A negative correlation was seen for seminal albumin and plasma follicle-stimulating hormone (r=-0.1, P=0.02) and a positive correlation for seminal albumin and serum inhibin B (r=0.2, P=0.004). Albumin exhibited positive correlations with the epididymal marker, NAG (r=0.5, P<0.001) and with the prostatic markers, PSA and zinc (r=0.1, P=0.001; r=0.2, P<0.001 respectively) as well as with age (r=0.2, P<0.001). A negative significant association was seen for seminal albumin and semen volume (beta=-0.60; 95% CI -0.80 to -0.30). The opposite trend was found regarding sperm concentration (beta=0.34; 95% CI 0.30-0.40), total sperm count (beta=0.30; 95% CI 0.20-0.40), and percentage morphologically normal spermatozoa (beta=0.70; 95% CI 0.10-1.0). No association was found between albumin and sperm motility, SCSA parameters, or fructose, the marker of seminal vesicles. Our results suggest testicular, epididymal and prostatic origin of seminal plasma albumin, in addition to the contribution from blood. This is the first study to demonstrate an association between seminal plasma albumin and sperm morphology. Further studies are needed to elucidate the role of seminal albumin in sperm morphology.     

Modulation of Fgf3 dosage in mouse and men mirrors evolution of mammalian dentition

A central challenge in evolutionary biology is understanding how genetic mutations underlie morphological changes. Because highly calcified enamel enables preservation of detailed dental features, studying tooth morphology enables this question to be addressed in both extinct and extant species. Previous studies have found that mutant mice can have severe abnormalities in tooth morphology, and several authors have explored the evolutionary implications of tooth number modifications in mutants. However, although they can potentially shed much light on evolutionary mechanisms, anomalies in tooth shape remain poorly studied. Here, we report that alterations in dosage of the Fgf3 gene cause morphological changes in both genetically engineered mutant mice and in human patients. By comparing the dental morphologies in mice and humans carrying Fgf3 mutations with primitive rodent and primate fossils, we determined that decreases in dosage of Fgf3 lead to phenotypes that resemble the progressive reappearance of ancestral morphologies. We propose that modifications in the FGF signaling pathway have played an important role in evolution of mammalian dentition by giving rise to new cusps and interconnecting cusps by new crests. We anticipate that our multidisciplinary study will advance the detailed correlation of subtle dental modifications with genetic mutations in a variety of mammalian lineages.     

Results after laparoscopic Heller-Dor operation for esophageal achalasia in 100 consecutive patients

The laparoscopic Heller-Dor operation has been the procedure of choice for the treatment of achalasia. However, because the incidence of achalasia is low, reports on the outcome of surgical treatment for achalasia are limited. In this study, the therapeutic results after laparoscopic Heller-Dor operation for achalasia at a single university hospital were evaluated. Between August 1994 and July 2006, 100 consecutive patients underwent laparoscopic Heller-Dor operation. The therapeutic results after laparoscopic Heller-Dor operation were assessed based on complications, operation time, blood loss, postoperative hospital stay, and the standardized questionnaire for satisfaction by telephone or outpatient clinic interview. With respect to perioperative complications, lower esophageal mucosal perforation occurred in 14 patients, but all of them could be suture-obliterated laparoscopically. One patient was converted to laparotomy because of uncontrolled bleeding from the short gastric artery. The mean operative time was 169 minutes, and the mean perioperative blood loss was 22 mL. The median postoperative hospital stay was 7 days. Reflux esophagitis, which was seen in five patients, was treated successfully with a proton pump inhibitor. According to the standardized questionnaire for satisfaction, 77 patients rated their recovery as 'excellent', 17 as 'good', 4 as 'fair', and 2 as 'poor'; thus, the overall success rate was 94%. There were no significant differences in surgical outcomes by morphologic type and severity of esophageal dilatation; however, the success rate deteriorated significantly with progression of the morphologic type. Laparoscopic Heller-Dor operation is a safe and effective surgical treatment for achalasia.