发酵乳制品与中老年人群健康相关性研究进展：来自队列研究的证据

发酵乳制品因发酵而发生结构和质地改变，并产生独特营养物质，且具有特殊的风味和营养特点，对中老年人健康具有较多健康益处。基于全球队列研究的相关证据，本文综述了发酵乳制品摄入与中老年人群超重/肥胖、心脑血管疾病、糖尿病前期和糖尿病、认知、肿瘤发生间的相关性，以及发酵乳制品潜在健康作用机制的研究进展。     

Ultrathin sP(EO-stat-PO) hydrogel coatings are biocompatible and preserve functionality of surface bound growth factors in vivo

Hydrogel coatings prepared from reactive star shaped polyethylene oxide based prepolymers (NCO-sP(EO-stat-PO)) minimize unspecific protein adsorption in vitro, while proteins immobilized on NCO-sP(EO-stat-PO) coatings retain their structure and biological function. The aim of the present study was to assess biocompatibility and the effect on early osseointegrative properties of a NCO-sP(EO-stat-PO) coating with additional RGD-peptides and augmentation with bone morphogenetic protein-4 (BMP) used on a medical grade high-density polyethylene (HDPE) base under in vivo circumstances. For testing of biocompatibility dishes with large amounts of bulk NCO-sP(EO-stat-PO) were implanted subcutaneously into 14 Wistar rats. In a second set-up functionalization of implants with ultrathin surface layers by coating ammonia-plasma treated HDPE with NCO-sP(EO-stat-PO), functionalization with linear RGD-peptides, and augmentation with RGD and BMP-4 was analyzed. Therefore, implants were placed subcutaneously in the paravertebral tissue and transcortically in the distal femur of another 14 Wistar rats. Both tests revealed no signs of enhanced inflammation of the surrounding tissue analyzed by CD68, IL-1ß-/TNF-α-antibody staining, nor systemic toxic reactions according to histological analysis of various organs. The mean thickness of the fibrous tissue surrounding the femoral implants was highest in native HDPE-implants and tended to be lower in all NCO-sP(EO-stat-PO) modified implants. Micro-CT analysis revealed a significant increase of peri-implant bone volume in RGD/BMP-4 coated samples. These results demonstrate that even very low amounts of surface bound growth factors do have significant effects when immobilized in an environment that retains their biological function. Hence, NCO-sP(EO-stat-PO)-coatings could offer an attractive platform to improve integration of orthopedic implants.     

Coatings from micropatterned sulfobetaine polymer brushes as substrates for MC3T3-E1 cells

In the last decades, polymer brush coatings have proven to be excellent anti-fouling materials by preventing protein adhesion. When using this property to restrict cell growth laterally in cell culture, it is crucial to ensure that other cell functions remain unaffected. The present study therefore examines MC3T3-E1 cell growth and morphology on patterned PSBMA brush substrates and probes their proliferation potential at mRNA level. The osteoblastic cells display a more elongated morphology than cells on the control substrates, but show no sign of elevated levels of the apoptosis marker p53 or diminished levels of Ki-67 or H4, which serve as indicators of proliferation. Therefore, patterned polymer brushes do not seem to influence cells in their proliferation state and are suitable cell culture substrates. Nevertheless, the use of polymer brush surfaces in long-term cell culture was found to be limited by their instability in cell culture medium.     

Comparative evaluation of modified trichrome and Uvitex 2B stains for detection of low numbers of microsporidial spores in stool specimens

At present, the laboratory diagnosis of intestinal infections caused by microsporidia depends on the detection of the typical spores either with a modified trichrome stain (MTS) or by staining with fluorochromes. The purpose of the present study was (i) to compare staining with MTS (MTS method) and the staining with the fluorochrome Uvitex 2B (U2B method) with respect to their sensitivities and specificities, particularly in the presence of low numbers of spores, and (ii) to evaluate their reliabilities under routine laboratory conditions. First, 30 negative human stool specimens as well as 30 specimens enriched with a low concentration of microsporidial spores were examined. The U2B and MTS methods detected 27 and 30, of the positive samples, respectively (95% confidence intervals for sensitivity, 0.73 to 0.98 for the U2B method and 0.88 to 1.00 for the MTS method) without yielding false-positive results (95% confidence intervals for specificity, 0.88 to 1.00 for the MTS and U2B methods). In addition, analysis of serial dilutions of 17 stool specimens from AIDS patients containing microsporidia revealed comparable detection thresholds (P = 0.52) for both methods. Finally, 40 slides prepared from one stool specimen containing very few microsporidia and 40 negative slides were included in the routine diagnostic program during 1 month in order to monitor laboratory handling and run-to-run variations. Again, both methods exhibited comparable sensitivities (95% confidence intervals, 0.83 to 0.99 for the MTS method and 0.91 to 1.00 for the U2B method) and specificities (95% confidence intervals, 0.91 to 1.00 for the MTS and U2B methods). In conclusion, MTS and U2B methods are equally useful in the diagnosis of microsporidiosis. However, since detection thresholds for both methods differed considerably in all diluted stool specimens, performance of a combination of both methods may be more sensitive than the performance of only one procedure in the event of very low numbers of microsporidial spores.     

Usage of polymer brushes as substrates of bone cells

Implant medical research and tissue engineering both target the design of novel biomaterials for the improvement of human health and clinical applications. In order to develop improved surface coatings for hard tissue (bone) replacement materials and implant devices, we are developing micropatterned coatings consisting of polymer brushes. These are used as organic templates for the mineralization of calcium phosphate in order to improve adhesion of bone cells. First, we give a short account of the current state-of-the-art in this particular field of biomaterial development, while in the second part the preliminary results of cell culture experiments are presented, in which the biocompatibility of polymer brushes are tested on human mesenchymal stem cells.     

益生菌对断奶鼠消化酶活力、肠道运动性及粘膜形态的影响

乳双歧杆菌、副干酪乳杆菌和植物乳杆菌是常见的益生菌,本研究系统评估了3株益生菌对断奶鼠消化代谢的调控作用。将断奶1周后的大鼠和小鼠分成对照组和益生菌处理组分别饲喂5周和4周,在此期间益生菌处理组每天分别灌胃1×109 CFU的乳双歧杆菌、副干酪乳杆菌和植物乳杆菌。试验期末,小鼠用于肠运动性试验,全部大鼠剖检取样进行生化及组织学分析。结果表明,乳双歧杆菌、副干酪乳杆菌和植物乳杆菌都能够显著促进小鼠肠道的运动性。同对照组相比,灌胃乳双歧杆菌、植物乳杆菌能够显著 （P<0.05） 增加大鼠的全期体重增重和肠液中胰蛋白酶活力,其中体重增重分别增加了13.33%和8.52%,胰蛋白酶活力分别提高了28.76%和31.13%。3株益生菌对大鼠的胃蛋白酶和淀粉酶活力、肝脏、脾脏、肾脏和胰腺重量及脏器系数均无显著影响。副干酪乳杆菌、植物乳杆菌均能够显著（P<0.05） 提高大鼠血清中总蛋白和球蛋白的含量,其中总蛋白含量分别增加了6.84%和9.12%,球蛋白含量分别增加了8.80%和6.82%。乳双歧杆菌、副干酪乳杆菌、植物乳杆菌生菌都会显著（P<0.05）升高大鼠血清中总胆固醇和高密度脂蛋白的含量,其中总胆固醇含量分别增加了44.35%、28.23%和17.74%,高密度脂蛋白含量分别增加了22.92%、27.08%和12.50%,对甘油三酯和低密度脂蛋白的含量无显著影响。此外,灌胃乳双歧杆菌、副干酪乳杆菌和植物乳杆菌均能够显著（P<0.05）提高大鼠的空肠和回肠绒毛高度和隐窝深度的比值以及回肠壁厚度,其中空肠绒毛高度和隐窝深度的比值分别增加了30.65%、19.35%和21.94%,回肠绒毛高度和隐窝深度的比值分别增加了30.21%、31.25%和35.94%,回肠壁厚度分别增加了21.14%、22.35%和27.51%。因此,乳双歧杆菌和植物乳杆菌能够通过促进肠道运动性、增加胰蛋白酶活力和改善肠道组织形态来促进宿主的消化吸收功能,进而提高宿主的体重增重同时又不会带来不良影响。     

Evaluation of Changes in Dislocation Density in TI-CP2 in the Process of Quasi-Static Loading Using Electrical Resistance Measurements

The paper focuses on the development of new methodology to evaluate increase of dislocation density in metals using electrical resistance measurements. Titanium specimens have been quasi-statically loaded with Instron testing machine till fracture and electrical resistance of the specimens have been monitored during the tests. Dislocation density was recovered from electrical resistance measurements and from SEM images before and after loading. Thus obtained results are shown to be in good agreement. The methodology developed in the present paper may be used for accurate monitoring of dislocation density in-situ.     

Work-related injuries and musculoskeletal disorders among factory workers in a major city of China

This study describes the frequency of occurrence of work-related injuries and musculoskeletal disorders (MSDs) among factory workers in Shenzhen, China, and examines the determinants of injuries and MSDs.     

Chemical nature of coal hydrogenation oils part 2. The effect of temperature

Hydrogenation of the same coal was carried out at 400, 450, 500, 550, 600, 650 and 700°C. ¹H-n.m.r. spectra of the oils (hexane soluble portion) showed an increase in the percentage of aromatic protons and a decrease in the percentage of aliphatic protons as the temperature increases, while the percentage of benzylic protons remained constant. The aromaticity of the oils as calculated by the Brown-Ladner equation increases with the reactor temperature. ¹³C-n.m.r. spectra of the oils indicates that the long aliphatic chains present decrease in both number and length as the reactor temperature increases. The molecular weight and viscosity of the oil as well as the percentage of polar compounds in the oil decrease with increasing temperature.