Loss of chloroplast-localized NAD kinase causes ROS stress in Arabidopsis thaliana

Journal of Plant Research - Chloroplast-localized NAD kinase (NADK2) is responsible for the production of NADP+, which is an electron acceptor in the linear electron flow of photosynthesis. The...     

华北蓟属植物的化学分类初探

本文对华北地区蓟属ＣｉｒｓｉｕｍＡｄａｎｓ．１６种植物的甲醇提取液紫外吸收光谱（ＵＶ）进行了比较研究。结果表明,蓟属植物的叶较其它部位的ＵＶ具有较好的稳定性和代表性,其光谱的特征可以作为属下分类的重要依据,其化学分类结果与形态分类基本一致。根据光谱特征,结合形态学及有关的细胞学和同工酶方面的资料,重新确立了Ｓｅｃｔ．Ｐｓｅｕｄｏ－Ｅｒｉｏｌｅｐｉｓ（Ｎａｋａｉ）Ｋｉｔａｍ．和Ｃ．ｓｅｇｅｔｕｍＢｇｅ．的组级和种级地位,最后,作者进一步讨论了光谱特征在化学分类中的意义。     

东北羊草草原综合生态因子对微生物生长的作用──IRM模型的研究

本文从分解者亚系统水平研究了东北羊草草原土壤中微生物生长的季节变化．多种生态因子的季节变化及环境因子对微生物的综合作用规律。微生物总数,总生物量和总呼吸强度的季节动态呈单峰上凸式曲线变化,８月份有明显的高峰值出现,它们分别为：２６８９．０×１０￣４个／ｇ·干土、２５．４１×１０￣（０３）ｇ／ｇ·干土、０．８９５２×１０￣（－３）ｇＣＯ＿２／ｇ·干土·ｄ。土壤生态因子的季节变化与土壤微生物呈现不同程度的正相关和负相关。同时利用ＩＲＭ的模型─—探讨了生态因子对微生物生长的综合作用规律：生态因子对微生物生长的综合作用指数ｒ＿ｎ在整个生长季节中为０．００３１８－０．１１１５,其中７－９月份ｒ＿ｎ较大,对出生物生长的限制作用较小,微生物生长较快,５、６和１０月份ｒ＿ｎ较小,对微生物生长限制作用较大,微生物生长较慢。     

细胞色素bc_1复合物的喇曼光谱研究

对提纯的细胞色素ｂｃ１复合物的氧化态和底物琥珀酸还原态两个样品进行了共振喇曼和富立叶喇曼光谱测定和比较。琥珀酸还原态与氧化态的共振谱比较明显有变化,而富立叶红外谱没有什么差别。说明呼吸链的电子传递体在氧化态与还原态交替变化进行电子传递时,蛋白总体构象不发生大的改变,而活性中心血红素辅基局部构象变化很大。     

Retinoblastoma,gross internal malformations,and deletion 13q14→q31

Summary A male patient with an interstitial deletion 13q14q31 is described. Our necropsy findings included a left retinoblastoma and several gross internal malformations. In this paper we reaffirm that band 13q14 is involved in cases of retinoblastoma and we propose, after studying accompanying cases of total or partial long arm trisomies 13, that the loss of specific 13q bands, from 13q14 to 13q31 is responsible for the congenital defects we are describing.     

Characterization of interleukin 2 stimulated 65-kilodalton phosphoprotein in human T cells

We have characterized the cellular proteins which are rapidly phosphorylated by interleukin 2 (IL 2) in a human IL 2 dependent cell line. When treated with IL 2, the phosphorylation of five proteins, 65, 50, 37, 24, and 21 kDa, was found in IL 2 dependent cell lines by two-dimensional gel electrophoretic analysis. After cell conversion from an IL 2 dependent state to an IL 2 independent state, one of the five phosphoproteins, the 65-kDa protein, became constitutively phosphorylated even without addition of IL 2. Also, in other IL 2 independent cell lines, such as KUT-2 and HUT-102, constitutive phosphorylation of the 65-kDa protein occurred without IL 2-stimulation. So our researchers were focused on biochemical characterization of the 65-kDa protein. It was found that the 65-kDa protein was one of the major cellular proteins by comparing the results of two-dimensional gel electrophoretic analysis of [32P]Pi-labeled and [3H]leucine-labeled cellular proteins and peptide mapping analysis. Subcellular fractionation studies indicated that the 65-kDa protein is a cytosol protein. The 65-kDa protein was purified from cytosol of a human T cell line, and its amino acid composition and amino acid sequences of its three oligopeptides were determined. It was found that the 65-kDa protein is identical with 1-plastin.     

A ROCK inhibitor promotes keratinocyte survival and paracrine secretion,enhancing establishment of primary human melanocytes and melanocyte–keratinocyte co‐cultures

Primary melanocytes isolated from skin and expanded in culture have been widely used for laboratory research and clinical applications. The conventional method to isolate primary melanocytes from skin usually requires about 3–4 weeks of culture for melanocytes to grow sufficiently to passage. Considering that melanocytes comprise only 3%–7% of epidermal cells in normal human skin, it would be extremely helpful to increase the isolation efficiency and shorten the initial culture time to quickly meet various application needs. Here, we report that adding Y‐27632, a Rho kinase inhibitor, into the initial culture medium for 2 days can dramatically increase the yield of melanocytes. We found that Y‐27632 can promote keratinocyte attachment and survival in the melanocyte culture system, resulting in not only better recovery, but also increased proliferation of melanocytes by a paracrine signaling pathway. More specifically, Y‐27632 significantly induced keratinocyte expression of stem cell factor, which played an important role in enhancing the growth of melanocytes. In summary, Y‐27632 could profoundly enhance the yield of primary melanocytes in the initial culture through paracrine effects on keratinocytes.     

不同生态保护地植物特征和土壤性质的对比研究——以黑河中游湿地为例

选择黑河中游张掖国家湿地公园和张掖黑河湿地国家级自然保护区为研究对象,对比分析了植物组成、物种多样性、植物生长状态、土壤养分、土壤理化性质及植物土壤间关系。结果显示:湿地公园的植物高度和土壤养分含量(有机碳、全氮、速效氮、全磷、速效钾)显著高于自然保护区,土壤理化性质含量(容重、pH)显著低于自然保护区,表明湿地公园有利于植物生长发育、土壤养分固存、改善土壤质地;自然保护区的植物科属种、多度、物种多样性(多样性指数、丰富度指数、均匀度指数)显著高于湿地公园,表明自然保护区有利于维持植物多样性;两种保护地中影响植物多样性的土壤因子不同,湿地公园物种多样性与土壤全磷和速效磷显著正相关,而自然保护区物种多样性与土壤盐分显著负相关。