Effects of inhibiting myosin light chain kinase on endothelin-1 induced proliferation and apoptosis of pulmonary arterial smooth muscle cells in rats

AIM: To investigate the effect of inhibiting myosin light chain kinase(MLCK) on endothelin-1(ET-1) induced proliferation and apoptosis of rat pulmonary artery smooth muscle cells(PASMCs). METHODS: Rat PASMCs were cultured and stimulated with ET-1. The cells were randomly divided into control group, ET-1 group and ET-1+MLCK inhibitor group(ET-1+M). Western blotting, MTT assay, [³H]-TdR incorporation and flow cytometry were employed to test the expression of myosin light chain(MLC) and MLCK, cell proliferation, cell cycle and apoptotic rate of PASMCs,respectively. The phosphorylation of MLC was determined by glycerol-PAGE coupled with Western blotting. RESULTS: Compared with control group, the protein expression of MLCK and MLC phosphorylation significantly enhanced after ET-1 stimulation. ET-1 markedly induced the proliferation and decreased the percentage of apoptotic rate in the PASMCs. However, pretreatment with ML-7, a MLCK inhibitor, significantly reversed the above effects induced by ET-1. CONCLUSION: MLCK inhibitor effectively inhibits the ET-1-induced proliferation and the cell cycle progression.     

Promoting effect of botulinum neurotoxin serotype A heavy chain on neuritogenesis in cultured Neuro-2a cells

AIM: To observe the neuritogenic actions of botulinum neurotoxin serotype A heavy chain (BoNT/A HC) on cultured Neuro-2a cells and to investigate the related signaling mechanisms for the effect of BoNT/A HC. METHODS: Neuro-2a cells were treated with different doses of BoNT/A HC (0.01, 0.1, 1 and 10 nmol/L), and then the cells were harvested at 24 h, 48 h and 72 h of BoNT/A HC exposure for detecting the neurite length and the percen-tage of the cells with neuronal processes by immunofluorescence staining. The most efficient dose of BoNT/A HC was chosen for exposure to Neuro-2a cells as the above. Whole cell protein was harvested at different time points for detecting the protein levels of phosphorylated ERK1/2 (p-ERK1/2) and phosphorylated Akt (p-Akt) by Western blot. RESULTS: Low doses of BoNT/A HC stimulated the neurite outgrowth, and increased the percentage of the cells with neurites compared with the negative controls (P<0.05), especially in the group with 1 nmol/L of BoNT/A HC treatment. Meanwhile, the phosphorylation of ERK1/2 and Akt was increased after treated with BoNT/A HC. There was an increasing tendency for the phosphorylation of ERK1/2 after the exposure of the cells to BoNT/A HC. The obvious increase in p-ERK1/2 was seen from 60 min to 5 h with 1 nmol/L of BoNT/A HC treatment (P< 0.05), and the increased protein level of p-Akt was mainly observed at 15 min and 60 min (P<0.05). CONCLUSION: BoNT/A HC stimulates the neuritogenesis. The neuritogenic mechanism of BoNT/A HC on Neuro-2a cells might be realized by activation of the phosphorylation of ERK1/2 and Akt.     

我国果蔬冷链物流建设现状及发展建议

我国是果蔬生产大国,果蔬具有易腐性,加之流通环节多、冷链设施不完备等诸多原因,导致果蔬的流通腐损率非常高。采用冷链物流可以有效地降低果蔬的流通腐损率、减少物流环节的消耗。目前,发达国家已经建立了完善的冷链物流体系,流通腐损率很低,但我国果蔬冷链物流体系建设比较滞后,冷链流通率远低于发达国家水平,发展果蔬冷链物流面临着严峻的考验。本文研究了果蔬冷链物流的发展现状,对各地区果蔬冷链物流现状进行了汇总,提出了果蔬冷链物流的发展对策和建议。     

锯链与链轮啮合的几何条件及节距偏差的影响

根据新型锯链的结构特点，参考链传动的几何条件，推导出一套锯链与链轮啮合传动的几何条件基本公式。这套公式涉及了等节距锯链和不等节距锯链两种情况，还涉及星形驱动链轮、轮辋式驱动链轮和星形导向链轮三种链轮。     

基于马尔可夫链的鸡西市土地利用结构预测

鸡西市是黑龙江省的第一大煤炭城市,对鸡西市土地利用结构进行分析和预测有助于在煤炭资源衰减的情况下为相关部门在调整全市的社会经济发展的策略、优化土地利用、保持土地的可持续利用发展等方面起到重要的参考作用。本文在对鸡西市土地利用现状分析的基础上,利用马尔可夫链对鸡西市未来土地利用结构进行预测。分析结果表明:从1996年到2005年鸡西市土地利用处于平稳发展期,预测到2020年也将处于平稳发展期,但从长远看将有大量耕地和林地退化为其他土地利用类型。     

Wax matters: absence of very‐long‐chain aldehydes from the leaf cuticular wax of the glossy11 mutant of maize compromises the prepenetration processes of Blumeria graminis

Conidial germination and differentiation, the so‐called prepenetration processes, of the barley powdery mildew fungus (Blumeria graminis f.sp. hordei) are triggered in vitro by very‐long‐chain aldehydes, minor constituents of barley leaf wax. However, until now it has not been demonstrated that these cuticle‐derived molecules also play a significant role in the initiation and promotion of the fungal prepenetration processes in vivo, on the surface of a living plant leaf. In the maize (Zea mays) wax mutant glossy11, which is completely devoid of cuticular very‐long‐chain aldehydes, germination and appressorial differentiation of B. graminis were strongly impeded. Spraying the mutant leaf surface with aldehyde‐containing wild‐type wax or pure n‐hexacosanal (C₂₆‐aldehyde) fully restored fungal prepenetration, whereas maize wild‐type leaf surfaces coated with n‐docosanoic acid exhibited reduced conidial germination rates of 23%, and only 5% of the conidia differentiated infection structures. In vitro studies were performed to further corroborate the extensive prevention of fungal germination and differentiation in response to artificial surfaces coated with aldehyde‐deficient maize wax. Because of its phenotype affecting the B. graminis prepenetration processes, the glossy11 mutation of maize may become a valuable molecular target and genetic tool that could provide a means of developing basal powdery mildew resistance in the globally important crops wheat and barley.     

运用马尔科夫链方法预测陕西苹果花期冻害年型

依据陕西29个苹果基地县1971～2007年4月极端最低气温资料,将陕西果区苹果花期冻害年型划分为严重冻害(NTd≤-2℃≥10),中等冻害(NTd≤-2℃<10 & NTd≤0℃≥15),轻度冻害(NTd≤-2℃<10 & NTd≤0℃<15 & NTd≤2℃≥19),和正常年型(NTd≤-2℃<10 & NTd≤0...     

黑龙江省非转基因大豆产业绿色供应链协同模式研究

以黑龙江省非转基因大豆产业为例,提出非转基因大豆产业绿色供应链协同模式形成的必要性与可行性。界定非转基因大豆产业绿色供应链协同的利益相关者,构建非转基因大豆产业绿色供应链协同模式的结构模型,并分别从战略协同、管理协同、操作协同三个维度探析了非转基因大豆产业绿色供应链协同模式。     

Bird flu (H7N9) outbreak and its implications on the supply chain of poultry meat in China

During the past two decades, food safety issues in China not only posed serious threats to Chinese consumers but also damaged the image of Chinese products internationally. In China, food safety is not only about scientific discoveries, advanced laboratories, and sanitation equipment; it is more about the role of different players in the food supply chain. The poultry meat supply chain is instrumental in the spread of the avian influenza A virus (H7N9), raising questions about how policymakers respond to such threats and whether industries need to be restructured to manage and control this epidemic so that it does not recur. As a short-term measure, to prevent the spread of this disease, government authorities enforced the closure of live bird markets (LBM) in disease-affected areas of China. However, in the long term, the poultry meat supply chain needs to be restructured. The aim of the current study was to analyze distribution channels for chicken meat in China and then describe arrangements in poultry meat sectors that incorporate small- and medium-scale producers into the supply chain while responding to shifts in LBMs. We also assessed the role of LBMs in spreading H7N9 and how these interventions affect the poultry meat supply chain in the Chinese market.     

农业供应链金融风险的主要特征与风险防范的基本原则

我国农业供应链突出表现为“集体化”、“现代化”和“生态化”，资金的安全性、流动性和信用程度都需要整体协同管控。交易成本和信息不对称决定了我国农业供应链以间接融资为主，其金融风险的特征主要表现为道德风险突出、整体风险难识别、可能引致区域系统性风险和行业系统性风险。因此，应当因地制宜确定农业供应链金融支持项目，并运用系统论原理控制农业供应链金融风险。