鼠伤寒沙门菌诱导自噬的分子机制研究进展

随着自噬现象的发现以来,有关自噬的研究在很多领域取得了重大突破,而鼠伤寒沙门菌与自噬之间的研究报道较少。文章主要阐述了自噬发生的整个机理过程,标志性蛋白LC3及其上下游蛋白Atg和p62之间的作用机制,自噬信号通路的激活位点和条件,基于鼠伤寒沙门菌刺激TLR系统激活TAK1,导致免疫细胞中的AMPK和ULK1的活化,抑制mTOR的活性,进一步阐述了沙门菌与自噬之间的相互关联性。     

细胞自噬相关信号通路分子在猪卵巢黄体形成与退化过程中的表达

为了研究细胞自噬相关信号通路分子在猪卵巢黄体发育与退化过程中的表达,本试验以猪卵巢为对象,分别采集卵泡期卵巢(F)、早期黄体(E)、中期黄体(M)和晚期黄体(L),应用Western blot检测LC3-B、p-Akt、Akt、p-JAK2、JAK2、p-STAT3及STAT3的表达,应用免疫组织化学技术检测STAT3在卵巢中的细胞定位。Western blot结果显示,LC3-B在早期及中期黄体表达量较高(P0.01);p-Akt在卵泡期卵巢的表达量高于黄体期(P0.05),且黄体发育的不同时期差异不显著(P0.05);p-JAK2在早期黄体表达量较高(P0.05);p-STAT3在晚期黄体表达量显著升高(P0.01)。Akt、JAK2与STAT3的表达量在整个卵巢周期无显著差异(P0.05)。免疫组化结果显示,STAT3主要定位在猪卵巢卵泡的颗粒细胞、膜细胞和黄体的类固醇生成细胞中。结果表明,猪黄体细胞的自噬可能受多种信号通路的协同调控,为进一步研究黄体形成和退化的分子机制提供依据。     

Application of coupled liquid chromatography–mass spectrometry in photolysis studies of the herbicide triflusulfuron‐methyl

The photochemical fate of the herbicide triflusulfuron‐methyl in aqueous solution under UV light (λ > 290 nm) was investigated. Nine photoproducts were detected and tentatively identified by LC/MS and LC/MS/MS analysis. The main routes of degradation involve the cleavage and/or contraction of the sulfonylurea bridge with the elimination of sulfur dioxide, which increases the acidity of the reaction medium. On the basis of the results obtained a photodegradation pathway is proposed. © 2001 Society of Chemical Industry     

1.8 GHz宽带低相位噪声CMOS压控振荡器设计

采用一种基于开关电容阵列(SCA)和尾电流源处加入电感电容滤波相结合的电路结构,设计了一个1.8 GHz宽带分段线性压控振荡器.采用TSMC 0.18μm 1P6MCMOS RF工艺,利用Cadence SpectreRF完成对电路进行的仿真.结果显示,在电源电压VDD=1.8 V时,控制电压范围为0.6~1.8 V,频率的变化范围为1.43~2.13 GHz,达到39%,相位噪声为-131 dBc/Hz@1MHz,功耗为9.36 mW(1.8 V×5.2 mA).很好地解决了相位噪声与调谐范围之间的矛盾.     

敌百虫和甲醛对淇河鲫仔鱼的急性毒性研究

[目的]研究药物对淇河鲫仔鱼的急性毒性。[方法]在室内常温、静水条件下,以淇河鲫仔鱼为受试生物,以致死率为指标,研究了甲醛和敌百虫对淇河鲫仔鱼的急性毒性。[结果]在同一暴露时间,随着甲醛和敌百虫溶液浓度增大,淇河鲫仔鱼的死亡率逐渐上升。敌百虫24、48、96h的半致死浓度（LC50）分别为108．63、89．20、75．30m#L,安全浓度（SC）为7．53mg／L;甲醛24、48、96h的半致死浓度（LC50）分别为165．33、134．04、119．42mg／L,安全浓度（SC）为11．94mg/L。[结论]在淇河鲫仔鱼疾病防治中,使用敌百虫较安全,而甲醛要慎用。     

球孢白僵菌MZ050724菌株对瓜实蝇的毒力测定

摘 要 本研究选用球孢白僵菌MZ050724菌株对瓜实蝇进行室内毒力测定,结果表明,在3.6?05-3.6?08个/ml 4个浓度中,成虫、幼虫和蛹的最大累计校正死亡率分别为(95.24?.55)%、(86.56?.88)%和(80.47?.86)%;其致死中浓度(LC50)分别为(2.544?.2846)?05个/ml、(2.9126?.4871)?05个/ml和(3.459?.4735)?05个/ml; 成虫、幼虫和蛹的致死中时间（LT50）分别为(4.643?.396)d(5.308?.225)d和 (6.139?.524)d。     

洛克沙胂对蚯蚓的急性毒性试验

试验用4种方法研究了兽药洛克沙胂对安德爱胜蚓(Eisenia andrei)的急性毒性。结果表明，用滤纸接触法测得洛克沙胂对蚯蚓的LC50为5．5g／kg；人工土壤法、人造土壤法和自然土壤法测得洛克沙胂对蚯蚓的LC50分别为：3．23、2．99、3．45g／kg土壤。洛克沙胂对蚯蚓的毒性较低。     

咖啡天蛾质型多角体病毒的生物活性测定

以不同浓度的咖啡天蛾(Cephonodes hylas)质型多角体病毒包含体悬液,浸渍栀子花叶,再喂食感染3龄初咖啡天蛾幼虫。感染浓度与死亡率回归方程式为y=2.690 7+0.464x,其致死中浓度LC50为9.483×10~4PIB/ml;5×10~7、5×10~6和5×10~5PIB/ml三种浓度的LT50值分别为:6.16、6.67和7.89天。 试验表明,同一浓度病毒(5×10~6PIB/ml)对不同龄期幼虫的感染力不同,幼虫死亡率随龄期增大而降低,从2龄的92.35％降到5龄的69.44％;其中LT50随着龄期递增而加大,从2龄的6.08天增加到5龄的7.63天。温度对幼虫感病死亡速度有一定影响,但对总死亡率影响不大,高温(35℃)对病毒的增殖起抑制作用,幼虫死亡率明显下降。     

Glyphosate accumulation,translocation, and biological effects in Coffea arabica after single and multiple exposures

In perennial crops like coffee, glyphosate drift exposure can occur multiple times during its commercial life span. Due to limited glyphosate degradation in higher plants, a potential accumulation of glyphosate could lead to increased biological effects with increased exposure frequency. In this study, we investigated glyphosate translocation over time, and its concentration and biological effects after single and multiple simulated spray-drift exposures. Additionally, shikimic acid/glyphosate ratios were used as biomarkers for glyphosate binding to its target enzyme.Four weeks after the exposure, glyphosate was continuously translocated. Shikimic acid levels were linear correlated with glyphosate levels. After two months, however, glyphosate appeared to have reduced activity. In the greenhouse, multiple applications resulted in higher internal glyphosate concentrations. The time of application, however, was more important regarding biological effects than the number of applications both in the greenhouse and in the field. In the field, berry yield, the most important biological response variable, was reduced 26% by the first out of four sequential applications of glyphosate at 64 g a.e. ha⁻¹ each. The three subsequent applications did not reduce yield any further.     

利用虫体蛋白特异性区分三种象虫

本文报道了利用聚丙烯酰胺凝胶电泳（PAGE）和凝胶渗透液相色谱法（GPC）分别对3种象虫虫体蛋白进行分离分析。初步分析结果表明：凝胶电泳法具有较高的分辨能力,电泳图谱能明显地区分3种象虫;凝胶渗透液相色谱法分析结果无差异,但对3种象虫虫体蛋白的胰蛋白酶水解液的分离结果有明显的区别。