黄金枸骨叶片复绿期叶绿素代谢的调控特征

为了探究黄金枸骨叶片变色期叶绿素代谢调控特征和叶片复绿期叶绿素合成中间产物的含量及关键酶活性.采用人工遮荫的方法,使黄金枸骨叶色由黄转绿,动态监测叶绿素的质量摩尔浓度、叶绿素合成前体物质的质量摩尔浓度、叶绿素合成酶活性和叶绿素降解酶活性的变化情况,分析叶片变绿过程中叶绿素生物合成代谢途径的特征.结果表明:叶片变色过程中叶绿素的质量摩尔浓度显著上升(P<0.05);δ-氨基乙酰丙酸(ALA)和胆色素原(PBG)的质量摩尔浓度显著下降(P<0.05),其后合成途径的中间产物尿卟啉原Ⅲ(UrogenⅢ)、粪卟啉原Ⅲ(CoprogenⅢ)、原卟啉IX(ProtoⅨ)、Mg-原卟啉Ⅸ(Mg-ProtoⅨ)、原叶绿素酸酯(Pchlide)的质量摩尔浓度显著增加(P<0.05);叶绿素合成相关酶,δ-氨基乙酰丙酸脱水酶活性显著下降(P<0.05),尿卟啉原Ⅲ合酶活性显著上升(P<0.05);叶绿素降解酶脱镁鳌合酶和叶绿素酶的活性显著下降(P<0.05).因此,黄金构骨叶色由黄变绿期间,叶绿素合成酶活性升高,叶绿素前体物质的质量摩尔浓度显著增加,叶绿素的积累起始于尿卟啉原Ⅲ的增加,起始时间为遮荫后6～15 d,同时叶绿素降解酶活性下降,促进了叶绿素的积累,叶绿素的质量摩尔浓度升高,叶片由黄转绿.     

薄皮甜瓜子叶组织培养的研究

以薄皮甜瓜品种“懒瓜王”子叶为材料,设置了15种激素组合的诱导芽分化培养基,进行了甜瓜子叶外植体诱导生芽试验和生根试验。结果表明,BA是甜瓜再生分化的关键物质,以BA浓度为4 .0mg/L(毫克/升)时,最有利于子叶外植体的分化生芽,在MS BA4 .0mg/L IAA0 .3mg/L(毫克/升)培养基中,甜瓜子叶的诱导生芽率高达93.75 %。不定芽经过伸长和生根获得了再生植株。同时又对子叶进行了横纵切的对照试验,以及芽的着生位置和形态的观察与研究。     

4种氨基糖苷类抗生素联用氯霉素对青海弧菌Q67 联合毒性作用及机制

近年来,氨基糖苷类(Aminoglycoside, AG)抗生素与氯霉素(Chloramphenicol, CHL)联用产生增毒作用而引起的死亡事件屡见不鲜。以4种AG抗生素：盐酸大观霉素(SPC)、硫酸小诺霉素(MCR)、硫酸丁胺卡那霉素(AMK)、妥布霉素(TOB)和氯霉素(CHL)为研究对象,选择青海弧菌(Vibrio qinghaiensis sp.-Q67,Q67)作为指示生物,采用直线均分法设计二元混合物,采用最小二乘法拟合浓度-效应数据,运用浓度加和(CA)模型对药物间的毒性相互作用进行评估,并同步分析抗生素联合毒性作用机理。结果表明：在暴露时间为12 h时,以半数浓度效应(EC₅₀)的负对数pEC₅₀值为毒性指标,5种抗生素的毒性大小顺序为TOB > CHL > MCR > AMK >SPC;4种AG抗生素与CHL的二元混合物的联合毒性作用特点因混合组分的不同而不同,Q67在二元混合物的EC₅₀浓度水平、暴露12 h后,细胞形态均未发生显著变化,而在单个抗生素的EC₅₀浓度、暴露12 h后,细胞明显受损,但损伤程度不同;大部分受混合物作用的Q67的发光相关物质含量在EC₅₀效应下均低于空白组,抗生素及其混合物的作用机制很可能是通过干扰发光菌体内蛋白质合成,进而导致细菌代谢紊乱,最终致其死亡。     

土壤熏蒸剂棉隆防治土传病害研究进展及未来发展趋势

棉隆对病原细菌、真菌、根结线虫及杂草均有较高防效,而且作为固体微颗粒剂具有使用简单、安全的特性,被广泛用于作物种植前熏蒸土壤以防治土传病虫害。施用过程中,土壤环境因素（包括土壤类型、土壤温湿度、土壤有机质及pH等）、施药方式、施药季节和施药剂量均会对棉隆的熏蒸效果产生显著影响,不正确的使用方式常会导致熏蒸效果不理想或产生药害问题。该文系统综述土壤熏蒸剂棉隆的使用概况（包括作用机制、适用作物、施用方式和施用效果等）、存在的问题及原因分析（包括施用深度、水分、温度对棉隆有效成分含量的影响及其熏蒸对土壤微生物群落结构的影响等）、解决对策（包括改善施药方式、优化土壤环境和活化熏蒸后土壤微生物等）以及未来发展趋势,以期为棉隆的高效应用提供借鉴。     

草栖钝绥螨对二斑叶螨的捕食作用

为明确草栖钝绥螨Amblyseius herbicolus对二斑叶螨Tetranychus urticae的控制潜能,在温度分别为19、22、25、28和31℃、相对湿度均为（85±5）%、光周期均为16 L∶8 D条件下测定草栖钝绥螨对二斑叶螨各螨态的捕食偏好性、捕食功能反应及自身干扰反应。结果表明,草栖钝绥螨对二斑叶螨幼螨和第1若螨具有嗜食性,对其捕食选择系数分别为2.22和1.27,均大于1.00,对二斑叶螨卵、第2若螨和雌成螨捕食选择系数分别为0.61、0.68和0.22,均小于1.00。在不同温度条件下,草栖钝绥螨对二斑叶螨各螨态的捕食功能反应均符合HollingⅡ型;在19～31℃范围内,草栖钝绥螨对二斑叶螨各螨态的瞬时攻击率、最大日捕食量和捕食能力均随着温度升高呈先升高后降低的趋势,在28℃时达到最大值;而草栖钝绥螨对二斑叶螨各螨态的处理时间随着温度升高呈先缩短后延迟的趋势,在28℃下处理时间最短。在相同温度下,草栖钝绥螨对二斑叶螨卵、幼螨和第1若螨的捕食作用较强。在有限的捕食空间和二斑叶螨密度固定的条件下,草栖钝绥螨单头捕食量和捕食作用率随其自身密度的增加而逐渐下降,说...     

Micro-computed tomography evaluation and pathological analyses of female rats with collagen-induced arthritis

Imaging techniques have been introduced to assess the efficacy and toxicity of developing pharmaceuticals. The purpose of this study was to perform a comprehensive characterization of collagen-induced arthritis (CIA) in rats using micro-computed tomography (micro-CT) and to compare the results with data from conventional pathological examination. Arthritis was induced by collagen in 24 female Wistar rats. Micro-CT and pathological analyses were performed to assess arthritis progression. Micro-CT analysis showed marked joint destruction occurring in a time-dependent manner following collagen administration. Bone volume was significantly decreased in the tibia at weeks 3 and 4 compared to week 0 (p < 0.05 and p < 0.01, respectively). Additionally, percent bone volume was significantly reduced in the tibia at week 4 compared to week 0 (p < 0.05). In contrast, bone surface/bone volume and trabecular separation were significantly increased in the tibia of the animals at week 4 compared to week 0 (p < 0.05). Severe joint destruction with extensive inflammation, erosion of cartilage and bone, and infiltration of inflammatory cells were observed in the knee joints of the collagen-treated rats. Taken together, micro-CT made it possible to quantify CIA lesions and should be performed with pathological examination in rats.     

Protective effect of butylated hydroxylanisole against hydrogen peroxide-induced apoptosis in primary cultured mouse hepatocytes

Butylated hydroxyanisole (BHA) is a synthetic phenolic compound consisting of a mixture of two isomeric organic compounds: 2-tert-butyl-4-hydroxyanisole and 3-tert-butyl-4-hydroxyanisole. We examined the effect of BHA against hydrogen peroxide (H₂O₂)-induced apoptosis in primary cultured mouse hepatocytes. Cell viability was significantly decreased by H₂O₂ in a dose-dependent manner. Additionally, H₂O₂ treatment increased Bax, decreased Bcl-2, and promoted PARP-1 cleavage in a dose-dependent manner. Pretreatment with BHA before exposure to H₂O₂ significantly attenuated the H₂O₂-induced decrease of cell viability. H₂O₂ exposure resulted in an increase of intracellular reactive oxygen species (ROS) generation that was significantly inhibited by pretreatment with BHA or N-acetyl-cysteine (NAC, an ROS scavenger). H₂O₂-induced decrease of cell viability was also attenuated by pretreatment with BHA and NAC. Furthermore, H₂O₂-induced increase of Bax, decrease of Bcl-2, and PARP-1 cleavage was also inhibited by BHA. Taken together, results of this investigation demonstrated that BHA protects primary cultured mouse hepatocytes against H₂O₂-induced apoptosis by inhibiting ROS generation.     

富硒女贞子粗多糖对小鼠免疫功能的影响

从富硒女贞子及女贞子中提取粗多糖,探讨其对小鼠免疫功能的影响。将90只小鼠随机均分为3组:对照组、富硒女贞子粗多糖组、普通女贞子粗多糖组。对照组灌服生理盐水,试验组小鼠灌服粗多糖液,灌服2次,每次连续5 d。2次灌胃的第3天注射卵清蛋白,二免后测定胸腺脾脏指数;MTT法检测脾淋巴细胞增殖水平;ELISA试剂盒检测血清中IL-2、IL-4、IFN-γ生成水平及相应抗体生成水平。结果显示:与对照组相比,试验组脾脏和胸腺指数明显升高,脾淋巴细胞增殖作用显著提高;IL-2、IL-4、IFN-γ生成水平明显提高,其中IFN-γ与对照组存在显著差异;而对特异性卵清抗体生成影响不大。这表明富硒女贞子粗多糖较普通女贞子粗多糖能更好地促进机体非特异性免疫及细胞免疫,从而增强机体免疫功能,在特异性体液免疫的作用方面则没有表现出明显的规律性,还需进一步研究。     

延边黄牛SREBP1和SCD1基因表达的发育性变化及与肌间脂肪含量的关联分析

文章旨在研究延边黄牛不同生长阶段固醇调节元件结合蛋白1(Sterol regulatory ele-ment binding factor 1,SREBP1)和硬脂酰辅酶A去饱和酶1(Stearoyl Co A desaturease 1,SCD1)基因表达的发育性变化与IMF含量的相关性以及这两个基因表达水平的关联性。试验选取12月龄的延边黄牛公牛(去势)8头,利用微量微创活体采样枪(韩国忠北大学提供),分别在12月龄,16月龄,20月龄,采集肌肉组织(臀肌);利用实时荧光定量PCR方法分析SREBP1和SCD1基因在延边黄牛不同生长阶段肌肉组织中的m RNA发育性变化。结果表明:1延边黄牛SREBP1基因相对表达水平在12、16、20月龄具有极其显著差异(P0.01),其中20月龄时SREBP1基因表达量相对最高;SCD1基因相对表达水平在12、16、20月龄具有显著差异(P0.05),其中20月龄时SCD1基因表达量相对最高。2肌肉组织中SREBP1基因的表达量在12~20月龄期间与IMF含量具有正向相关性,相关系数为0.910(P0.05);SCD1基因的表达量在12~20月龄期间与IMF含量具有正向相关性,相关系数为0.934(P0.05)。结果表明,SREBP1和SCD1基因在延边黄牛不同生长阶段存在显著或极显著差异,SREBP1和SCD1基因的协同表达对延边黄牛不同生长阶段肌内脂肪的沉积有一定的正向调控作用。     

Ecotourist trail-use affects the taxonomic,functional and phylogenetic diversity of mammals in a protected area: lessons for conservation management

Ecotourism, by definition, aims to engage peoples’ interest in wildlife and the environment. The use of tourist roads and trails to access sites within protected areas (PAs) can detrimentally affect the behavior and distribution of species. The way mammals respond to anthropogenic pressures may differ across taxonomic, functional, and phylogenetic groups; nevertheless, how ecotourist trail-use affects these different diversity remains under-investigated. Here, we assessed 6 metrics of taxonomic, phylogenetic, and functional diversity for a mammal community in a PA in central China, recording how Trail use (using Trail type as a proxy) and habitat variables affected sightings and signs of mammals across 60 replicate 0.5 km transects. We then examined how Trail use affected the taxonomic, functional, and phylogenetic diversity indices of species (>1 kg). Using generalized liner mixed modeling, we identified that more used trail types had a greater adverse effect on all diversity richness indices than did less used trail types. Consequently, tourist pressure was associated with a general tendency to homogenize the site's mammal community. In contrast, the effects of Trail Types on all diversity evenness indices were non-significant. Furthermore, more developed and more heavily used trail types had a greater, significant negative effect on taxonomic, functional, and phylogenetic richness, whereas these richness indices were unaffected by minor trail types, used less intensively. As a general principle, lower biodiversity indices reduce ecosystem resilience, and so it is vital to better understand these responses to balance public access against biodiversity management in PAs.