Electrospun sodium alginate/poly(ethylene oxide) core-shell nanofibers scaffolds potential for tissue engineering applications

Core-shell structure nanofibers of sodium alginate/poly(ethylene oxide) were prepared via electrospinning their dispersions in water solution. The core-shell structure morphology of the obtained nanofibers was viewed under scanning electron microscope (SEM) and transmission electron microscope (TEM), and X-ray photoelectron spectroscopy (XPS) analysis was used to further quantify the chemical composition of the core-shell composite SA/PEO nanofibers surface in detail. Furthermore, one-step cross-linking method through being immersed in CaCl₂ solution was investigated to improve the anti-water property of the electrospun nanofibers mats in order to facilitate their practical applications as tissue engineering scaffolds, and the changes of the structural of nanofibers before and after cross-linking was characterized by Fourier transform infrared (FT-IR). Indirect cytotoxicity assessment indicated that SA/PEO nanofibers membrane was nontoxic to the fibroblasts cells, and cell culture suggested that SA/PEO nanofibers tended to promote fibroblasts cells attachment and proliferation. It was assumed that the nanofibers membrane of electrospun SA/PEO could be used for tissue engineering scaffolds.     

虫瘿—昆虫与植物互作的奇特产物

虫瘿是昆虫刺激产生的植物不正常组织。造瘿昆虫几乎能在高等植物的所有类群中产生形态各异的虫瘿,甚至能在同一种植物上形成多种形态不一的虫瘿。虫瘿形成的机制仍不清楚,普遍认为是昆虫控制了虫瘿的形成,但植物细胞也参与了虫瘿形成的调控。为了探索这一神秘的领域,科学家们已经对昆虫的刺激物以及植物的反应作了大量的研究,未来工作的难点将是如何把二者联系起来。     

盐度对高体革鯻生长和肉质的影响

盐度是水产养殖环境的重要理化因子,与养殖动物的渗透压、生长、发育关系密切,探索盐度对水产动物生长发育的影响,可为充分利用内陆盐水水域发展养殖提供可靠的理论依据。国内外有关盐度对鱼类生长、发育、代谢的研究早有报道,但关于盐度改善淡水鱼类肉质的研究较少,仅见李小勤、刘贤敏等学者研究盐度对草鱼(Ctenopharyngodon idellus)、奥尼罗非鱼(Oreochromisniloticus × O. aureus)、长江口纹缟虾虎鱼(Tridentigertrigonocephalus) 乌鳢(Channa argus)、斑点叉尾(Ietalurus punetaus)生长和肉质影响报道。高体革(Scortum barcoo)隶属鲈形目、科、革属, 是近几年我国从澳大利亚引进的淡水养殖新品种。       

微流控芯片检测肺癌患者血浆中p16基因异常甲基化在临床应用的评价

肺癌是常见的恶性肿瘤之一,其死亡率和发病率在世界范围的肿瘤性疾病中均居高不下.p16基因启动子区异常甲基化被认为是肺癌发生中的一起早期事件.为了提高检测异常甲基化方法的灵敏度及特异性,利用微流控芯片检测p16基因的异常甲基化,通过对肺癌患者血浆标本的检测,使病人血浆中的p16基因甲基化的异常改变可能成为辅助肺癌早期诊断和高危人群筛选的分子标记物,以期建立一种崭新而可靠的早期肺癌临床诊断方法.     

角质细胞生长因子研究进展

角质细胞生长因子(KGF)从属于成纤维细胞生长因子家族。KGF基因表达受多种细胞因子调控。KGF与受体KGFR特异性的结合发挥其多种生物学功能：参与组织、器官的发育;参与皮肤、胃、肠、肾、膀胱、肺等上皮的损伤修复;减少放、化疗所带来的副作用,具有损伤防护功能;KGF与肿瘤密不可分。     

子午岭天然林与人工林群落特征比较研究

采用标准样地调查法对比研究了黄土高原子午岭地区人工刺槐林、人工油松林与天然林山杨林、白桦林与辽东栎林的群落特征。结果表明,人工林与天然演替森林（山杨林与自桦林）均具有较丰富的物种组成,为62种左右,而天然顶极森林（辽东栎林）的物种数量则相对较少,为48种。人工林与天然林空间层次分化明显,而且还有一定数量的层间藤本植物。从群落结构的空间格局来看,人工油松林与天然林乔木层与灌木层发育较好,但人工刺槐林的草本层发育较好。人工林的植物多样性主要体现在草本层,而天然林乔木层与灌木层也具有相对较高的多样性。以天然辽东栎林为参照,群落物种组成相似性的比较结果表明,人工刺槐林与天然林的相似性较低,其相似性指数（IS）为19．4,而人工油松林与天然林的相似性则较高,IS值为43．4,甚至高于天然白桦林（33．3）与山杨林（42．9）。因此,相比较而言,油松比刺槐更适合作为黄土高原子午岭地区的人工造林树种。     

Differentiation of velogenic, mesogenic and lentogenic strains of Newcastle disease virus by multiplex RT-PCR

A multiplex RT‐PCR technique has been developed for differentiation of velogenic, mesogenic and lentogenic pathotypes of Newcastle disease virus (NDV), using a set of three oligonucleotide primers designed from NDV genomic RNA (P1, P2 and P3). The primer pair P1 and P2 generated a RT‐PCR product of 204 bp, only with RNA from velogenic and mesogenic strains, whereas the P1 and P3 generated a 364 bp product only with RNA from mesogenic and lentogenic strains. Thirty four NDV strains, including some reference strains (known pathotypes), NDV field isolates and NDV vaccine strains, as well as other avian virus strains, were tested with multiplex RT‐PCR. All reference strains tested were differentiated in agreement with their intracerebral pathogenicity index (ICPI) values or with the pathotypes known in previous reports. The nucleotide sequence analysis of RT‐PCR products for four NDV strains was fully in agreement with the RT‐PCR characterisations of these strains. The RT‐PCR results of other avian RNA viruses further confirmed the reliability and specificity of this technique. However, the RT‐PCR failed to detect some other avian NDV, which may not originate from chicken. This multiplex RT‐PCR technique is simple and easy to perform. It could be applied not only to determine the origin of NDV, but also may be used diagnostically in molecular epidemiological analysis of ND and for prediction of pathotypes of NDV isolates.     

不同提取剂对麦醇溶蛋白提取效果的电泳比较

以大麦、小麦品种为材料,分别采用醇溶蛋白提取剂乙醇、乙二醇、2-氯乙醇、2-巯基乙醇、尿素等配成不同浓度的单一组分提取剂和复合提取剂,在同一条件下提取大麦和小麦去胚种子的醇溶蛋白,通过A-PAGE分离样品液发现,单一组分提取剂中25％的2-氯乙醇效果较好,5％的2-巯基乙醇效果较差;复合提取剂中由2-氯乙醇和2-巯基乙醇组成的提取剂效果最好。这种复合提取剂制备的样品液经电泳后,在图谱中条带丰富,带型清晰,无论对大麦还是小麦种子,都是最佳的醇溶蛋白提取剂。     

酸梨金属元素的分析

采用电感耦合等离子体发育光谱仪（ICP）对野生酸梨的金属元素进行了测试分析。结果表明：其常量元素中Ca的含量高达66.84%(mg/g),同时含有人体必需的微量元素Fe,Mn,V,Cu,Zn,Ni,Co等。及对人体有益的稀土元素Nd,Tm,Yb等。     

鱼类Fc受体研究

Fc受体是免疫细胞表面一种重要受体分子,通过与免疫球蛋白Fc段结合触发多种生物学功能,是联系体液免疫和细胞免疫的桥梁。部分硬骨鱼中已经发现了Fc受体,在斑马鱼、斑点又尾鲴和鲤鱼中都克隆到了Fc受体的γ亚基,在鲨鱼和大西洋鲑中证明有能够与免疫球蛋白结合的Fc受体存在,并在斑点叉尾鲴、河豚和虹鳟中存在着类似α亚基的Fc受体。对鱼类Fc受体的发现和研究必将为了解鱼类的免疫机制及免疫进化提供重要的资料。