Mechanism of RhoA on vascular reactivity following hemorrhagic shock in rats

AIM: To observe the mechanisms of RhoA on vascular reactivity following hemorrhagic shock (HS) in rats. METHODS: The superior mesenteric artery (SMA) in rats subjected to hemorrhagic shock was adopted to assay the vascular reactivity via observing the contraction initiated by norepinephrine (NE) with isolated organ perfusion system. Meanwhile, the effects of Rho kinase, myosin light chain phosphatase (MLCP), myosin light chain kinase (MLCK) on RhoA regulating vascular reactivity were observed. The effects of RhoA agonist U-46619 and inhibitor C3 enzyme on the activities of Rho kianse, MLCP, MLCK and phosphorylation of MLC20 in the vascular smooth muscle cells (VSMC) with hypoxia were also measured. RESULTS: As compared to control group, the cumulative dose-response curves of SMA to NE at 2 h after shock shifted to the right, the maximal contractions (Emax) of NE was significantly decreased. RhoA agonist U-46619 increased the vascular reactivity in the late period of shock. C3 enzyme abolished U-46619 induced the increase in the contractile response of SMA to NE. Rho kinase inhibitor Y-27632 decreased U-46619-induced the increase in the vascular reactivity, MLCP inhibitor calyculin further promoted the increase in the vascular reactivity. However, MLCK inhibitor had no effect on the U-46619-induced change of vascular reactivity. After hypoxia, the activities of Rho kinase and MLCK, and the level of MLC20 phosphorylation were decreased, MLCP activity was increased. RhoA agonist U-46619 increased the activity of Rho kinase and phosphorylation of MLC20, decreased the activity of MLCP, but had no effects on MLCK activity. CONCLUSION: RhoA plays an important role in the regulation of vascular reactivity following shock. The mechanism is closely related to regulating the activities of Rho kinase and MLCP, and increasing the phosphorylation of MLC20 in VSMC.     

会宁县牛产业发展现状及对策

为明确会宁县牛产业发展现状,为下一步发展提供决策依据,对全县牛产业发展情况进行了全面调查,掌握了县内牛产业发展现状和存在的问题,经汇总、分析和讨论后提出了牛产业发展的一些意见和建议。     

木材预干的原理及实用技术

文章将木材预干的方法分为三类,并分别阐述了各类预干法的概念、特点,并从木材内部水分子移动的规律及外部空气自然循环着手,对木材预干的机理进行了论述。针对采用气干预干法操作的企业提出了几点注意事项。就北方林区预干法的使用提出了具体建议。     

Overhead supplemental far-red light stimulates tomato growth under intra-canopy lighting with LEDs

Far-red(FR) light regulates phytochrome-mediated morphological and physiological plant responses.This study aims to investigate how greenhouse tomato morphology and production response to different durations of FR light during daytime and at the end of day(EOD).High-wire tomato plants were grown under intra-canopy lighting consisting of red(peak wavelength at 640 nm) and blue(peak wavelength at 450 nm) light-emitting diodes(LEDs) with photosynthetic photon flux density(PPFD) of 144 μmol m–2 s–1 at 10 cm away from the lamps,and combined with overhead supplemental FR light(peak wavelength at 735 nm) with PPFD of 43 μmol m–2 s–1 at 20 cm below the lamps.Plants were exposed to three durations of FR supplemental lighting including: 06:00–18:00(FR12),18:00–19:30(EOD-FR1.5),18:00–18:30(EOD-FR0.5),and control that without supplemental FR light.The results showed that supplemental FR light significantly stimulated stem elongation thereby resulting in longer plants compared with the control.Moreover,FR light altered leaf morphology toward higher leaf length/width ratio and larger leaf area.The altered plant architecture in FR supplemented plants led to a more homogeneous light distribution inside the canopy.Total plant biomass was increased by 9–16% under supplemental FR light in comparison with control,which led to 7–12% increase in ripe fruit yield.Soluble sugar content of the ripe tomato fruit was slightly decreased by longer exposure of the plants to FR light.Dry matter partitioning to different plant organs were not substantially affected by the FR light treatments.No significant differences were observed among the three FR light treatments in plant morphology as well as yield and biomass production.We conclude that under intra-canopy lighting,overhead supplemental FR light stimulates tomato growth and production.And supplementary of EOD-FR0.5 is more favorable,as it consumes less electricity but induces similar effects on plant morphology and yield.     

Role of PPARα/PGC-1α in doxorubicin induced mouse dilated cardio-myopathy

AIM: To investigate the changes of peroxisome proliferator-activated receptors (PPAR)α/peroxisome proliferator activated receptor coactivator 1 alpha (PGC-1α) in doxorubicin (DOX) induced dilated cardiomyopathy (DCM) and its effect on the energy metabolism and myocardial function in mice. METHODS: Forty mice were randomly divided into 4 groups: control group, DOX group, PPARα inhibitor group and PPARα agonist group. The DCM model was established by injection of DOX. The protein levels of PPARα/PGC-1α were detected. The PPARα inhibitor and PPARα agonist were used 2 weeks beforeinjection of DOX. The contents of adenine acid and phosphocreatine (Pcr) in the mitochondria were measured by high-performance liquid chromatography (HPLC). The ANT activity was analyzed by the atractyloside-inhibitor stop technique. The changes of the echocardiography and hemodynamics were also observed. RESULTS: DOX induced DCM model was successfully established. The protein levels of PPARα and PGC-1α in control group were significantly higher than those in DOX group (P<0.05). Both of the high-energy phosphate contents and the transport activity of ANT were decreased in DOX group (P<0.05), and the hemodynamic parameters were disordered (P<0.01). Compared with DOX group, PPARα inhibitor pre-treatment significantly reduced the PPARα/PGC-1α expression. Meanwhile, high-energy phosphate contents in the mitochondria and the ANT transport activity of the mitochondria decreased, as well as the left ventricular function (P<0.05). On the other hand, PPARα agonist significantly increased the expression of PPARα and PGC-1α, and improved the transport activity of ANT. In addition, the hemodynamic parameters were ameliorated, but the high-energy phosphate contents of the mitochondria did not significantly change. CONCLUSION: PPARα/PGC-1α plays an important role in the regulation of ANT transport activity in dilated cardiomyopathy induced by DOX, and the activation of PPARα/PGC-1α has protective effects on the DCM induced by DOX.     

长沙市郊枫香人工林降水再分配及养分动态

采用定位试验研究方法对长沙市郊枫香人工林生态系统水文过程及养分动态进行了研究.结果表明：该森林生态系统春季平均降雨量为18.73 mm,其中以林冠穿透雨形式输入林地水量占降雨量的81.63%,以树干流形式输入林地水量占1.54%;树冠截留率随降雨量的增大而减小,平均树冠截留率为16.83%;在枫香人工林中,降水pH值的变化不大,且基本呈中性;养分元素质量浓度在各过程中变化不尽相同,Ca^2＋、K^＋质量浓度在穿透水和树干茎流中呈上升趋势,NH4^＋质量浓度在树干茎流中呈上升趋势,Zn^2＋、PO4^3-质量浓度呈下降趋势,Mg^2＋、Cu^2＋质量浓度变化不大.     

5个玉米人工合成群体选系的配合力分析

选用8个自交系为测验种,采用不完全双列杂交设计,对5个玉米人工合成群体新选的15个自交系的配合力、杂种优势以及主要性状遗传参数进行了分析。结果表明,单株产量GCA表现突出,且构成产量因子性状GCA表现也较好的新选自交系有GP2-1,GP5-2和GP5-5;SCA值高、杂种优势强的组合是48-2×GP3-3和ES40×GP1-2;在穗长、秃尖长、穗粗等12个性状中,亲本的基因加性效应对F1性状形成起主导作用,而穗重和单株产量的遗传变异主要来自于基因非加性效应。因此,对于高产组合的选配,至少要选择1个GCA高的材料作亲本,并在此基础上兼顾SCA的选择,而利用群体自交选系则应根据性状遗传特性决定其选择时期和选择强度。     

兔出血症病毒抗原捕获ELISA检测方法的建立

用兔出血症病毒（RHDV）单克隆抗体包被酶标板,以兔多克隆抗体作为夹心抗体,建立RHDV抗原捕获ELISA检测方法,优化反应条件并对该方法的敏感性、特异性、重复性、稳定性等指标进行了测试和评价。结果表明,单抗最佳包被质量浓度为1mg/L,兔多抗血清最佳质量浓度为4mg/L。本方法可特异性地检测出兔肝脏病料中的RHDV,纯化病毒的最低检出量为26μg/L。对已知阳性样品的检测显示,捕获ELISA检测的病毒滴度是HA试验的3～13倍。对67份可疑病料,捕获ELISA阳性检出率为62.7%,HA试验阳性检出率为55.2%。用不同批次包被的酶标板重复检测已知样品显示出良好的重复性。本方法敏感性、特异性、稳定性良好,可应用于RHDV的快速、批量、特异检测。     

水稻物质生产特性及其与产量的关系研究

以汕优63、Ⅱ优162、Ⅱ优419、K18A/149和65002为材料,在云南省涛源乡、宾川县和杭州市富阳县进行试验,分析了水稻高产的物质生长特性,并比较了不同环境下物质生长特性的差异及原因。结果表明:云南涛源和宾川产量分别比杭州高80%和66%,导致云南产量较高的主要原因是生物产量较高。生物产量差异主要在幼穗分化以后,尤其是灌浆结实期。在云南生态条件下,中后期能容纳较高的叶面积系数(LAI),群体生长速率(CGR)较高,使花后物质生产量大,且花后物质运转量也较高。     

中华蜜蜂和意大利蜜蜂对糖浓度的反应

为了研究蜜蜂嗅觉反应,选取葡萄糖、蔗糖和果糖,将浓度为1%,3%,5%,7%的糖对饿过2 h的蜜蜂进行不接触刺激,观察蜜蜂吻伸展的情况.结果表明:当糖浓度在1%～5%时,随着糖浓度增加,中蜂和意蜂吻伸展率都显著性增大;糖浓度为1%和3%时,中蜂显著偏好于蔗糖,但当浓度等于或高于5%时,中蜂吻伸展率在各类糖之间差异不显著.意蜂在糖浓度为1%时,蜜蜂偏好于蔗糖和果糖,但当浓度等于或高于3%时,则蜜蜂吻伸展率在各类糖之间差异不显著.