光照强度和土壤水分对辣椒品质和产量的影响

通过3个光照水平（自然光照—L1、遮阴30%—L2和遮阴70%—L3）及4个土壤水分水平（土壤相对含水率分别为田间持水率的40%～55%—W1、55%～70%—W2、70%～85%—W3、85%～100%—W4）试验,研究了其对辣椒品质及产量和水分利用效率（WUE）的影响。结果表明,①自然光及遮阴30%下,随着土壤含水...     

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.     

Effects of myosin light chain kinase on regulation of endothelial barrier function

Myosin light chain kinase (MLCK) activates the regulatory light chain of myosin II, and the phosphorylated myosin light chain leads to actomyosin contractile activity, as well as the cell contraction and increasing intercellular gap, which finally results in endothelial barrier dysfunction. MLCK-dependent hyperpermeability occurs in response to multiple cell signaling molecules and signaling pathways, including Ca²⁺, Src, PKC, NO, cGMP and mitogen activated protein kinases (MAPK). In this review, different mechanisms of endothelial hyperpermeability mediated by MLCK are discussed.     

精口恶唑禾草灵抗性及敏感菵草种群萌发条件的比较

为了比较对精口恶唑禾草灵抗性及敏感菵草种群在萌发特性上的差异,采用培养皿法研究了温度、光照、pH值、水势、盐胁迫对其萌发的影响。结果表明,pH值为4-10条件下,2个种群的萌发率无显著性差异;全光照条件下,抗性菵草的萌发率显著低于敏感菵草;10℃条件下,抗性菵草的萌发率显著低于敏感菵草;水势胁迫和盐分胁迫对抗性菵草萌发的影响大于敏感菵草,当水势为-0.5 MPa时,抗性菵草无萌发,敏感菵草萌发率为41.9%;当NaC l溶液浓度为160 mmol/L时,抗性菵草无萌发,敏感菵草的萌发率为51.7%。     

葫芦科作物耐弱光研究进展

综述了近年来国内外葫芦科作物耐弱光研究进展,包括形态指标、生理生化指标、光合代谢等方面,并指出了目前存在的主要问题和研究方向。     

晴天和阴天对刺槐光合生理特性的影响

以渭北地区刺槐为研究对象,采用LI-6400便携式光合作用系统,于2009年6月和8月分别在晴天和阴天条件下,测定刺槐光合作用的日进程及光合光响应曲线.结果表明:无论在6月还是8月,晴天刺槐的净光合速率(Pn)和气孔导度(Ga)在10:00以前高于阴天,而在午间12:00和14:00低于阴天.刺槐的胞间CO2浓度(Ci)、空气CO2浓度(Ca)、空气相对湿度(RH)、光能利用率(LUE)在晴天的绝大多数时间显著低于阴天,而蒸腾速率(Tr)、水汽压亏缺(VPD)、光合有效辐射(PAR)、空气温度(Ta)在晴天的全天都显著高于阴天.在晴天条件下,虽然刺槐的Ga,Ci,Ca,RH,LUE的日均值比阴天低,但Pn,Tr,VPD,PAR,Ta的日均值比阴天高,从而能够积累更多的日均光合固碳量.在阴天条件下,刺槐的最大光合速率(Pmax)高于晴天,且暗呼吸速率(Rd)和光补偿点(LCP)显著低于晴天,表现出很强的光合适应能力.     

油茶轻基质无纺布容器育苗技术

在常规的油茶芽苗砧嫁接育苗技术基础上,初步探索了油荼轻基质无纺布容器育苗技术.结果表明,采用轻基质无纺布容器育苗技术,一年生油茶嫁接成活率可达85.7％,苗木合格率可达到93.4％,其中Ⅰ级苗62.7％,Ⅱ级苗30.7％,当年可出圃.结合使用特定的育苗托盘,可有效减少育苗工序,降低育苗成本.该技术可操作性强、成活率及出...     

轻型木结构用工字搁栅特点及质量要求

简述了轻型木结构用工字搁栅特点及其制造工艺,介绍了北美工字搁栅的质量和性能以及主要测试项目、原理、特征值计算和评价方法等。

Abstract：

The manufacturing technology and characteristics of I-joist used for light wood structures are introduced in brief.The requirements for quality and performance of I-joist in North America as well as relevant test items,principles,characteristic value calc     

光辐射对农业土壤的影响

核爆炸产生的光辐射，能量大，发射率高，在一定数值内可使土壤表层熔融，沸腾，并随着光冲量值的减弱轻。表层熔融的土壤，机械组成有微小的变化，有机质，全氮量有部分减少，但不影响整个耕层土壤的耕作性能，在此土壤上种植农作物，生长良好，产量正常。