二步法三维编织复合材料弹性性能的有限元法预报

用有限元法预测了二步法三维编织复合材料的有效弹性性能。在二步法方型三维编织复合材料细观结构大单胞模型的基础上,考虑复合材料中纤维束的连续性及其空间的交织效应,用离散杆单元构成的桁架结构有限元模型等效代替复合材料承受单轴拉伸载荷时的受力响应。同时,以轴向拉伸性能测试试样为对象,应用有限元软件包MARC的结构静力分析部分计算了轴向弹性模量和泊松比,数值计算结果与实验结果一致性较好。参数分析结果表明,轴向弹性模量随轴纱与编织纱线密度之比和节距长度的增加呈增加趋势。

Ti_(40)Zr_(40)Ni_(20)合金急冷薄带的组织与相变行为

采用单辊甩带法在不同转速下制备Ti40Zr40Ni20合金薄带,通过X射线衍射(XRD)和透射电子显微术(TEM)分析各样品的急冷组织,并结合热分析方法,研究它们加热时的组织演化行为与相变特征。研究结果表明:随着甩带速率从40 m/s下降到10 m/s,Ti40Zr40Ni20薄带样品中依次生成了单相非晶、非晶+β-Ti(Zr)混合相和单相准晶组织;除单相铸态准晶外,前两种急冷组织在温度接近300℃时开始失稳生成纳米尺度的准晶相,当温度上升到540℃附近,组织中出现了cF96-(Zr,Ti)2Ni大单胞面心立方相(点阵参数a≈1.2 nm)。

Safety and clinical efficacy of granulocyte and monocyte adsorptive apheresis therapy for ulcerative colitis

Active ulcerative colitis （UC） is frequently associated with infiltration of a large number of leukocytes into the bowel mucosa. Therefore, removal of activated circulating leukocytes by apheresis has the potential for improving UC. In Japan, since April 2000, leukocytapheresis using Adacolumn has been approved as the treatment for active UC by the Ministry of Health and Welfare. The Adacolumn is an extracorporeal leukocyte apheresis device filled with cellulose acetate beads, and selectively adsorbs granulocytes and monocytes/macrophages. To assess the safety and clinical efficacy of granulocyte and monocyte adsorptive apheresis （GMCAP） for UC, we reviewed 10 open trials of the use of GMCAP to treat UC. One apheresis session （session time, 60 min） per week for five consecutive weeks （a total of five apheresis sessions） has been a standard protocol. Several studies used modified protocols with two sessions per week, with 90-min session, or with a total of 10 apheresis sessions. Typical adverse reactions were dizziness, nausea, headache, flushing, and fever. No serious adverse effects were reported during and after GMCAP therapy, and almost all the patients could complete the treatment course. GMCAP is safe and well-tolerated. In the majority of patients, GMCAP therapy achieved clinical remission or improvement. GMCAP is a useful alternative therapy for patients with steroid-refractory or -dependent UC. GMCAP should have the potential to allow tapering the dose of steroids, and is useful for shortening the time to remission and avoiding re-administration of steroids at the time of relapse. Furthermore, GMCAP may have efficacy as the first-line therapy for steroid-naive patients or patients who have the first attack of UC. However, most of the previous studies were uncontrolled trials. To assess a definite efficacy of GMCAP, randomized, doubleblind, sham-controlled trials are necessary. A serious problem with GMCAP is cost; a single session costs ￥145 000 （$1 300）. However, if this treatment prevents hospital admission, re-administration of steroids and surgery, and improves a quality of life of the patients, GMCAP may prove to be cost-effective.

Contribution of mononuclear bone marrow cells to carbon tetrachloride-induced liver fibrosis in rats

AIM： To study the inhibitory effect of mononuclear bone marrow cell （BNC） transplantation on carbon tetrachloride （CCl4） -induced liver fibrosis in rats. METHODS： Rat liver fibrosis models were induced by CCl4 and alcohol administration. After 8 wk, twenty rats were randomly allocated into treatment group （n = 10） and control group （n = 10）. BMC were infused into the rats in treatment group via the portal vein, while heparinized saline was infused in control group. CCl4 was hypodermically injected into the rats twice a week for 4 wk. At the end of wk 12, all rats were humanely sacrificed. Uver samples were taken and stained with HE or Masson trichrome. The general conditions, liver fibrosis （hydroxyproline and collagen fibre） and liver pathological grades in rats were evaluated. RESULTS： The general conditions of the rats in treatment group improved markedly, but not in control group. Hydroxyproline was 504.6± 128.8 μg/g in treatment group, and 596.0 ± 341.8 μg/g in control group. The percentage of collagen fibre was 3.75% ± 0.98% in treatment group and 5.02% ± 0.44% in control group. There was a significant difference between the two groups （P 〈 0.05）. Liver pathological grade decreased from grade N to grade 11 partially in treatment group （P 〈 0.05） with no obvious improvement in control group （P 〉 0.05）. There was a significant difference between treatment group and control group （P 〈 0.05）.CONCLUSION： Transplantation of BMC can improve liver fibrosis due to chronic liver injury in rats.

Emerging Trends for Microbiome Analysis： From Single-Cell Functional Imaging to Microbiome Big Data

Method development has always been and will continue to be a core driving force of microbiome science, In this perspective, we argue that in the next decade, method development in microbiome analysis will be driven by three key changes in both ways of thinking and technological platforms： ① a shift from dissecting microbiota structure by sequencing to tracking microbiota state, function, and intercellular interaction via imaging; ② a shift from interrogating a consortium or population of cells to probing individual cells; and ③a shift from microbiome data analysis to microbiome data science. Some of the recent methoddevelopment efforts by Chinese microbiome scientists and their international collaborators that underlie these technological trends are highlighted here. It is our belief that the China Microbiome Initiative has the opportunity to deliver outstanding ＂Made-in-China＂ tools to the international research community, by building an ambitious, competitive, and collaborative program at the forefront of method development for microbiome science.

Effect of Inoculants Mixture on Nutrient Uptake and Growth in Cucumber(Cucumis sativus L. ) Seedlings

[Objective]we checked the role of various proportion of three growth promoting bacteria to determine the optimum proportion with greater symbiosis in cucumber seedlings. [Method]Three strains of Rhodopseudomonas palustrisSH2,Bacillus megateriumSHⅡ3,Bacillus mucilaginosusSH1 were applied in this study. Cucumber were cultured in plastic pot,inoculating mixture with seven different proportion for 28 days. [Result]2:1:2 treatment had the strongest effect on N,P,K uptake and concentrations in the soils,on increasing enrich of Fe and Zn inroots and shoots and on plant height,stem diameter,dry weight,relative chlorophyll contents. Treatments of 1:1:2 and 1:1:1 were following ,while the weakest effect was given by 1:2:2,2:2:1 and 1:2:1 treatments. [Conclusion]2:1:2 is the optimum proportion of the three bacteria for nutrition uptake and growth of cucumber seedlings.

Enhancing the culturability of bacteria from the gastrointestinal tract of farmed adult turbot Scophthalmus maximus

Eighteen agar media were tested for the culture of gut-associated bacteria from farmed adult turbot （Scophthalmus maximus）, including 16 agar media with or without 1% gastrointestinal （GI） supernatant, or with 2% or 4% GI supernatant. A total of 1 711 colonies were analyzed and 24 operational taxonomic units （OTUs） were identified. The greatest bacterial diversity was isolated on Zobell 2216E/ Zobell 2216E＋ agar media, whereas MRS/MRS＋ agar media produced a low diversity of colonies, Agar media with GI supernatant （1%, 2%, or 4%） showed increased diversity and yielded different profiles of OTUs from the corresponding original media, suggesting that GI supernatant provides substances that enhance the culture efficiency of bacteria from the turbot GI tract. The large majority of the colonies （82%） were 7-Proteobacteria, whereas 15.6% and 2.4% of colonies were Firmicutes and Actinobacteria, respectively. At the genus level, 49.4% of all colonies were assigned to Vibrio. Other potential pathogens, including Pseudomonas, Photobacterium, and Enterobacter, and potential probiotics, including Bacillus, Paenibacillus, and Pseudomonas, were also isolated on agar media. Most cultured bacteria belonged to species that were first described in the turbot GI tract. The impact of these species on turbot physiology and health should be investigated further.

Neurolin expression in the optic nerve and immunoreactivity of Pax6-positive niches in the brain of rainbow trout(Oncorhynchus mykiss) after unilateral eye injury

In contrast to astrocytes in mammals, fish astrocytes promote axon regeneration after brain injury and actively participate in the regeneration process. Neurolin, a regeneration-associated, Zn8-1abeled protein, is involved in the repair of damaged optic nerve in goldfish. At 1 week after unilateral eye injury, the ex- pression of neurolin in the optic nerve and chiasm, and the expression of Pax6 that influences nervous system development in various brain regions in the rainbow trout （Oncorhynchus mykiss） were detected. Immunohistochemical staining revealed that the number of Zn8~ cells in the optic nerve head and intraor- bital segment was obviously increased, and the increase in Zn8~ cells was also observed in the proximal and distal parts of injured optic nerve. This suggests that Zn8＊ astrocytes participate in optic nerve regeneration. ELISA results revealed that Pax6 protein increased obviously at 1 week post-injury. Immunohistochemi- cal staining revealed the appearance of Pax6＋ neurogenic niches and a larger number of neural precursor cells, which are mainly from Pax6＋ radial glia cells, in the nuclei of the diencephalon and optic tectum of rainbow trout （Oncorhynchus mykiss）. Taken together, unilateral eye injury can cause optic nerve reaction, and the formation of neurogenic niches is likely a compensation phenomenon during the repair process of optic nerve injury in rainbow trout （Oncorhynchus mykiss）.

Replication of M13 single-stranded DNA bearing a sitespecific ethenocytosine lesion by Escherichia coil cell extracts

Previous investigation on the mutagenic effects of 3,N4-Ethenocytosine (εC), a nonpairing DNA lesion,revealed the existence of a novel SOS-independent inducible mutagenic mechanism in E. coli termed UVM for UV modulation of mutagenesis. To investigate whether UVM is mediated by an alteration of DNA replication, we have set up an in vitro replication system ill which phage M13 viral single-stranded DNA bearing a single site-specific (εC) residue is replicated by soluble protein extracts from E. coli cells. Replication products were analyzed by agarose gel electrophoresis and the frequency of translesion synthesis was determined by restriction endonuclease analyses. Our data indicate that DNA replication is strongly inhibited by εC, but that translesion DNA synthesis does occur in about 14% of the replicated DNA molecules. These results are very similar to those observed previously in vivo, and suggest that this experimental system may be suitable for evaluating alterations in DNA replication in UVM-induced cells.

Preparation of stable micropatterns of gold on cell-adhesion-resistant hydrogels assisted by a hetero-bifunctional macromonomer linker

Surface patterning is very useful in biomaterial studies, yet it is not easy to prepare a micropattern with cell-adhesion contrast that is stable in a wet environment. Recently, a platform technique of transfer photolithography was invented to fabricate stable metal microarrays on the surface of a cell-adhesion resistant and mechanically biomimetic poly（ethylene glycol） hydrogel; the linker is the key chemical in such a transfer strategy. This article reports the design and synthesis of a hetero-bifunctional macromonomer linker with a thiol group at one end and an acryloyl group at the other end. The bifunctional linker was char- acterized by GPC and ~H NMR, and the average number of thiol groups in the bifunctional linker was detected by Ellman＇s reagent. The regent stability under wet conditions was also confirmed by the model reactants. The resultant micropatterned surfaces are meaningful for future studies of cell behaviors on mechanically biomimetic matrixes.