栓皮栎林的生物量

本文对北京西山海拔300米的26年生人工栓皮栎林的生物量作了测定。粮据十株伐倒的标准木分别取得乔木各部分的干重。采用W=a(D2H)b的幂函数方程,获得每公顷土地上的树干重32.16吨,枝条重9.85吨、叶重1.68吨、根重9.95吨。对灌木和草本植物采用收割法作测定：灌木的地上部分每公顷为1.33吨,地下部分为2.3吨;草本植物的地上部分每公顷为0.15吨,地下部分为0.8吨。所以栓皮栎的地上部分总生物量每公顷为45.17吨,地下部分13.05吨,总计58.22吨。     

森林公园在我国自然保护区系统中的地位

本文针对我国森林公园建设发展迅速的现状,阐述了“森林公园”的自然保护性质和作用,提出“国家自然保护区系统”的概念,将森林公园与自然保护区、风景名胜区三个体系同视为“国家自然保护区系统”中的三个组成部分,并阐述了这三个体系各自的特点、地位及其相互关系。同时,还提出进一步加强森林公园管理的建议。     

棉铃虫发生与北太平洋海温的遥相关 及其长期灾变预警

本文分析了山东郓城26年（1974～1999）、德州22年（1978～1999）和江苏丰县20年（1980～1999）棉铃虫百株累计卵量与北太平洋海温的遥相关关系及其时空动态规律,并选出相关显著程度P<0.05概率水平、空间分布范围较大、持续时间较长而稳定的组合作为关键预测因子组建了郓城、德州棉铃虫三代卵,丰县棉铃虫二代卵的预测模型,并筛选出最优长期灾变预警模型。结果表明：① 北太平洋海温场与棉铃虫种群数量消长存在显著或极显著的遥相关区域,其位置及范围随时间变化,但存在若干呈现出空间稳定性和时间持续性的大面积相关显著区域。② 郓城棉铃虫三代卵量和丰县棉铃虫二代卵量与北太平洋海温场的相关区分布形式很相似,与前两年1月份北太平洋月平均海温场存在大片相关显著的区域（35°～ 55°N,135°E～135°W）,持续时间达4个月之久;而德州棉铃虫三代卵量与前两年7～9月份北太平洋低纬度海温有大范围相关显著区（1°～17°N,165°E～120°W）。 ③ 用前两年1～11月份北太平洋海温场相关显著区内各格点的月平均海温距平的平均值做因子建立了棉铃虫长期灾变预警模型,预测检验结果表明：郓城棉铃虫三代卵6年（1994～1999）中报准5年,丰县棉铃虫二代卵5年（1995～1999）中报准3年,德州棉铃虫三代卵5年（1995～1999）全部符合。据此可提前20～27个月做棉铃虫的长期灾变预警。     

微生物1,3-1,4-β-葡聚糖酶蛋白质改造及工业应用研究进展

1,3-1,4-β-葡聚糖酶(E.C.3.2.1.73)是一种重要的工业用酶,其可以通过特异性切割毗邻β-1,3-糖苷键的β-1,4-糖苷键将β-葡聚糖或地衣多糖降解为纤维三糖和纤维四糖。微生物β-葡聚糖酶属于糖苷水解酶家族16,其三维结构为卷心蛋糕状的逆向β-片层结构。文中综述了近些年来β-葡聚糖酶在工业上的应用情况及酶蛋白质工程改造的研究进展,并对其研究前景进行了展望。     

薏苡胚发育及贮藏营养物质积累的研究

薏苡（Ｃｏｉｘ ｌａｃｒｙｍ ａ－ｊｏｂｉ）胚发育分下列各期：棒形胚前的原胚期、棒形胚期、胚芽鞘期、１叶期、２ 叶期、３叶期、４ 叶期、５ 叶期及６叶期成熟胚。３ 叶期胚具１ 条不定根（种子根）,４ 叶期具２ 条,５ 叶期及成熟胚期具３ 条。不定根与胚根排成１ 纵行。营养物质最先在盾片细胞中积累。开花后９ 天的１ 叶期胚,在盾片、胚芽鞘及胚轴细胞中积累了淀粉,以后遍及成熟胚的各部分。淀粉粒含量与器官发生及生长顺序成正相关,但发育后期,盾片细胞内的淀粉粒含量下降。开花后１０ 天,盾片细胞中形成含晶体的蛋白质体,晶体含蛋白质及植酸钙镁。以后,这种蛋白质体增多、增大。同时,又形成不含晶体的蛋白质体。一定时期,含晶体的蛋白质体消失,不含晶体的蛋白质体增多,直到胚成熟。开花后１３ 天,胚芽鞘上部细胞形成蛋白质体。以后遍及成熟胚的各部分,器官发生越早,所含蛋白质体越多、越大。开花后１０ 天,盾片细胞中产生了脂体,成熟胚的盾片细胞,含有大量的脂体。还观察了胚发育各期与颖果及盾片长度的对应关系     

Protein phosphatase 5 is required for ATR-mediated checkpoint activation

In response to DNA damage or replication stress, the protein kinase ATR is activated and subsequently transduces genotoxic signals to cell cycle control and DNA repair machinery through phosphorylation of a number of downstream substrates. Very little is known about the molecular mechanism by which ATR is activated in response to genotoxic insults. In this report, we demonstrate that protein phosphatase 5 (PP5) is required for the ATR-mediated checkpoint activation. PP5 forms a complex with ATR in a genotoxic stress-inducible manner. Interference with the expression or the activity of PP5 leads to impairment of the ATR-mediated phosphorylation of hRad17 and Chk1 after UV or hydroxyurea treatment. Similar results are obtained in ATM-deficient cells, suggesting that the observed defect in checkpoint signaling is the consequence of impaired functional interaction between ATR and PP5. In cells exposed to UV irradiation, PP5 is required to elicit an appropriate S-phase checkpoint response. In addition, loss of PP5 leads to premature mitosis after hydroxyurea treatment. Interestingly, reduced PP5 activity exerts differential effects on the formation of intranuclear foci by ATR and replication protein A, implicating a functional role for PP5 in a specific stage of the checkpoint signaling pathway. Taken together, our results suggest that PP5 plays a critical role in the ATR-mediated checkpoint activation.     

植物甜蛋白des-pGlu1-Brazzein基因在乙醇氧化酶缺陷型甲醇酵母中的表达及其活性分析

采用BglⅡ酶切重组表达载体pPIC9K-Bra,纯化后电击转化甲醇酵母菌GS115,构建乙醇氧化酶缺陷型表达菌株GS115-pPIC9K-Bra,筛选鉴定后,以0.5％的甲醇进行诱导,表达的目的蛋白约占上清总蛋白的95％,纯度较高,并具有一定的甜度.成功构建了乙醇氧化酶缺陷型的甲醇酵母表达菌株,为深入研究其应用奠定了基础.     

BDCA2/Fc?RIγ Complex Signals through a Novel BCR-Like Pathway in Human Plasmacytoid Dendritic Cells

Dendritic cells are equipped with lectin receptors to sense the extracellular environment and modulate cellular responses. Human plasmacytoid dendritic cells (pDCs) uniquely express blood dendritic cell antigen 2 (BDCA2) protein, a C-type lectin lacking an identifiable signaling motif. We demonstrate here that BDCA2 forms a complex with the transmembrane adapter FcɛRIγ. Through pathway analysis, we identified a comprehensive signaling machinery in human pDCs, similar to that which operates downstream of the B cell receptor (BCR), which is distinct from the system involved in T cell receptor (TCR) signaling. BDCA2 crosslinking resulted in the activation of the BCR-like cascade, which potently suppressed the ability of pDCs to produce type I interferon and other cytokines in response to Toll-like receptor ligands. Therefore, by associating with FcɛRIγ, BDCA2 activates a novel BCR-like signaling pathway to regulate the immune functions of pDCs.     

Characterization of full-length enterovirus 71 strains from severe and mild disease patients in northeastern China

Human enterovirus 71 (EV71)-associated hand, foot, and mouth disease (HFMD) has been a leading cause of childhood infection in China since 2008. Epidemic and molecular characteristics of HFMD have been examined in many areas of China, including the central and southern regions. However, clinical and genetic characterization of EV71 in the northeastern region of China is scarce. In this study, a series of analyses were performed on seven full-length EV71 sequences from HFMD patients who had either severe or mild disease. We have determined that these seven circulating EV71 viruses from Changchun, China are actually complex recombinant viruses involving multiple type A human enterovirus (HEV). Classified as EV71 subtype C4 (EV71 C4), these Changchun EV71 viruses contain genetic recombination events between the CA4, CA5, EV71B4 and EV71C1 strains. Most of the structural protein region (P1) of these viruses resembled that of the prototype EV71 C1 strains. The non-structural protein domains (P2 and P3) showed a high degree of similarity with CA4, CA5 and EV71 B4 in different regions. The 5'UTR had unclassified recombination,while partial 3D region of these viruses showed a high degree of similarity to CA16. Phylogenetic analysis of full-length or partial sequences of isolates from severe or mild disease patients in Changchun always formed a single cluster in various phylogenetic analyses of different genomic regions, suggesting that all seven strains originated from one single common ancestor. There was no correlation between viral genomic sequence and virulence. Thus, we found that circulating recombinant forms of EV71 are prevalent among HFMD patients in Northeastern China. The existence of a unique cluster of EV71 related viruses in Northeast China has important implications for vaccine development that would address the increasing prevalence of HFMD.