大麦黄矮病毒(BYDV-GPV)的循回传播机理

对植物组织中蚜虫口针分泌的胶状唾液染色观察发现，蚜虫刺探时口针穿行在细胞间隙，仅在吸食时下颚口针进入细胞内。禾谷缢蚜饲毒１２ｈ时ＲＴ－ＰＣＲ方法在后肠、血淋巴液和附唾液腺中检测到ＧＰＶ；而非介体麦长管蚜在ＧＰＶ毒源上吸食２４ｈ时，仅在后肠组织中检测到ＧＰＶ；当继续取食４８ｈ时，在后肠及血淋巴液中也发现了ＧＰＶ，但仍无能力进入附唾液腺，说明蚜虫后肠和附唾液腺对病毒均有专化选择作用，禾谷缢管蚜传播ＢＹＤＶ－ＧＰＶ时存在吸食、获毒和传毒三个阶段。     

Role for the membrane receptor guanylyl cyclase-C in attention deficiency and hyperactive behavior

Midbrain dopamine neurons regulate many important behavioral processes, and their dysfunctions are associated with several human neuropsychiatric disorders such as attention deficit hyperactivity disorder (ADHD) and schizophrenia. Here, we report that these neurons in mice selectively express guanylyl cyclase-C (GC-C), a membrane receptor previously thought to be expressed mainly in the intestine. GC-C activation potentiates the excitatory responses mediated by glutamate and acetylcholine receptors via the activity of guanosine 3',5'-monophosphate-dependent protein kinase (PKG). Mice in which GC-C has been knocked out exhibit hyperactivity and attention deficits. Moreover, their behavioral phenotypes are reversed by ADHD therapeutics and a PKG activator. These results indicate important behavioral and physiological functions for the GC-C/PKG signaling pathway within the brain and suggest new therapeutic targets for neuropsychiatric disorders related to the malfunctions of midbrain dopamine neurons.     

平衡施肥对麻竹产量及品质的影响初报

设置3因素3水平正交设计L9(33)的麻竹肥料试验。其结果表明:(1)施肥对麻竹产量有极显著的增产效应,氮、磷、钾增产的主次顺序为N>P>K。麻竹产量与施肥量回归方程y=84.30X1-86.44X2 152.15X3-0.229X12 0.947X1X2-0.769X22-0.736x1x3 0.953x32 17744(X1:施N量kg/hm2,X2:施P2O5量kg/hm2,X3:施K2O量kg/hm2,Y:产量kg/hm2),且差异达极显著;(2)最佳施肥配比N:P2O5:K=1:0.51:0.58,最大产量为44491.86kg/hm2,对应的年最大产量施肥量为N:228.71kg/hm2,P2O5:115.58kg/hm2,K2O:132.88kg/hm2;(3)施肥对笋中含N、P、K含量有显著影响;(4)施肥对笋中粗蛋白含量影响极显著主次顺序N>P>K     

人工感染MDV雏鸡免疫器官中PMG~ 浆细胞动态观察

本研究对健康和免疫后接种京毒—1号MD强毒鸡中枢免疫器官中PMG~ 浆细胞的动态变化进行了观察。结果表明:健康攻毒组免疫器官中的PMG~ 浆细胞数在攻毒后3天开始下降,15～20天后迅速回升,30天左右达到峰值,以后又迅速下降;而在免疫攻毒组,免疫器官中的PMG~ 浆细胞数在20天以前一直处于较高的水平,之后和对照组差异不明显。     

Polar lightning and decadal-scale cloud variability on Jupiter

Although lightning has been seen on other planets, including Jupiter, polar lightning has been known only on Earth. Optical observations from the New Horizons spacecraft have identified lightning at high latitudes above Jupiter up to 80 degrees N and 74 degrees S. Lightning rates and optical powers were similar at each pole, and the mean optical flux is comparable to that at nonpolar latitudes, which is consistent with the notion that internal heat is the main driver of convection. Both near-infrared and ground-based 5-micrometer thermal imagery reveal that cloud cover has thinned substantially since the 2000 Cassini flyby, particularly in the turbulent wake of the Great Red Spot and in the southern half of the equatorial region, demonstrating that vertical dynamical processes are time-varying on seasonal scales at mid- and low latitudes on Jupiter.     

Protective role of heat-shock protein 70 in gastric mucosal lesion induced by endotoxin in cirrhotic rats with portal hypertensive gastropathy

AIM: To investigate the protective role of heat-shock protein 70 (HSP70) in the pathogenesis of gastric mucosal damage in cirrhotic rats with portal hypertensive gastropathy (PHG).METHODS: The rat model of liver cirrhosis with PHG was established by injection with tetrachloride.The animals were divided into normal control group, PHG group, PHG+heat treatment group, PHG+BPI21 group and PHG+endotoxin groups.The endotoxin used in the experiment was at the dose of 3 mg/kg and endotoxin antagonist BPI21 was at the dose of 2 mg/kg.HSP70 was induced by pre-treating the animals with mild whole-body heating.The levels of HSP70 and tumor necrosis factor alpha (TNF-α) in the gastric mucosa were measured by ELISA.Furthermore, the pathological changes of the gastric mucosa were observed under microscope with HE staining.RESULTS: Compared with the normal control rats, the rats in PHG group showed obvious gastric pathological lesion, decrease in HSP70 production and increase in TNF-α level in the gastric mucosa, and increased endotoxin concentration in the plasma.Compared with PHG+endotoxin group, the gastric mucosal lesion in PHG+BPI21 group was significantly attenuated, accompanied by the increase in HSP70 production and decrease in TNF-α level in the gastric mucosa.Heat treatment increased HSP70 production and decreased TNF-α concentration in the PHG rats, thus attenuating the gastric mucosal damage.CONCLUSION: HSP70 alleviates the gastric mucosal lesion induced by endotoxin in cirrhotic rats with PHG and decreases the concentration of TNF-α in gastric mucosa, indicating a protective role of HSP70 in the pathogenesis of gastric mucosal damage in PHG.     

Comparison of metabolic profiling of cyanidin-3-O-galactoside and extracts from blueberry in aged mice

The metabonomics changes of plasma and brain tissue after dietary supplementation with blueberry extracts (BBE) and cyanidin-3-O-galactoside from blueberry (BBM) in aged mice were investigated by (1)H NMR technique. The mice received intragastric administration of BBE (200 mg/kg/day), BBM (50 mg/kg/day), and saline water (0.9%) for 6 weeks, respectively, in the BBE, BBM, and control groups. At the end of the experiment, plasma and brain samples were collected for NMR analysis. The results demonstrated that the level of choline in plasma from BBE and BBM groups were obviously elevated relative to the control group, whereas the levels of lactate and phosphocholine in plasma were remarkably reduced. Compared with those in the control group, the levels of choline and GABA in the brain from the BBE group were obviously increased, whereas glutamate and phosphocholine in the BBE group were significantly decreased. The level of taurine in the brain from the BBM group was particularly higher than that in the control group. These results indicated supplementation with BBE or BBM might induce similar changes of endogenous plasma and brain metabolic profiles in aged mice.     

Apple polyphenols extend the mean lifespan of Drosophila melanogaster

Apple polyphenols (AP) are an excellent source of dietary antioxidants. The present study investigated the effect of AP on the lifespan of fruit flies and their interaction with gene expressions of superoxide dismutase (SOD), catalase (CAT), methuselah (MTH), Rpn11, and cytochrome c oxidase (CcO) subunits III and VIb. Results showed the mean lifespan was significantly extended by 10% in fruit flies fed the AP diet. This was accompanied by up-regulation of genes SOD1, SOD2, and CAT and down-regulation of MTH in the aged fruit flies. Paraquat and H(2)O(2) challenge tests demonstrated that AP prolonged the survival time only for Oregon R wild type flies but not for SOD(n108) or Cat(n1) mutants, in which either SOD or CAT was knocked out. Chronic paraquat exposure could shorten the maximum lifespan from 68 to 31 days and reduce the climbing ability by 60%, whereas AP could partially reverse the paraquat-induced mortality and decline in climbing ability. AP could up-regulate Rpn11 at day 30, whereas it appeared to have no significant effect on gene expression of ubiquitinated protein, CcO subunits III and VIb. These AP-induced changes were unlikely associated with caloric restriction as the gustatory assay found no difference in average body weight and stomach redness index between the control and AP fruit flies. It was therefore concluded that the antiaging activity of AP was, at least in part, mediated by its interaction with genes SOD, CAT, MTH, and Rpn11.     

玉米秸秆芯结构建模与径向压缩过程模拟

为了深入研究实芯作物秸秆的压缩特性,以农大108玉米秸秆芯为研究对象,基于秸秆各向异性、非均质、非线性特点,先通过径向压缩试验获取其粘弹性参数,然后应用ANSYS软件建立了玉米秸秆芯横截面圆柱有限元结构模型,并进行径向压缩过程和应力松弛过程的数值模拟.研究表明,五参量广义麦克斯韦模型能较好地描述玉米秸秆芯应力松弛特性,模型拟合参数的试验值与有限元模拟值误差均小于10％.试验验证了玉米秸秆芯模拟结果的可行性和计算模型的有效性.