模拟干旱胁迫下川白芷种子萌发特性的研究

研究干旱胁迫对川白芷种子萌发的影响及其种苗的抗旱性.方法以川白芷种子为试验材料,采用PEG - 6000模拟干旱条件,测定种子发芽率、种苗生长情况、丙二醛(MDA)的含量、超氧化物歧化酶(SOD)的活性等指标.结果随着胁迫程度的增加,川白芷种子发芽率、种苗生长等指标总体表现先升后降的趋势;而种苗MDA的含量与SOD的活...     

人工模拟干旱胁迫下金银花幼苗的生理适应性反应

目的研究人工模拟干旱胁迫条件下金银花幼苗的生理适应性反应,为揭示金银花植株的抗旱机制以及抗旱品种的选育提供理论依据。方法采用聚乙二醇（PEG-6000）模拟干旱胁迫处理金银花幼苗,检测幼苗体内的丙二醛（MDA）含量;超氧化物歧化酶（SOD）、过氧化物酶（POD）、过氧化氢酶（CAT）、抗坏血酸过氧化物酶（APX）等保护酶活性,渗透调节物质脯氨酸（Pro）和可溶性糖含量。结果 10%、20%和30%PEG处理幼苗后120 h MDA含量分别高出对照组20.31%、28.12%和36.72%,随着PEG浓度升高,MDA含量逐渐增加。SOD、POD、CAT和APX活性总体呈现先升高后降低的趋势,各种酶对干旱胁迫的响应速率不同,CAT于干旱胁迫后立即开始启动,SOD、POD于干旱胁迫后24 h启动,而APX于干旱胁迫后48 h开始启动。Pro和可溶性糖含量均于处理后24 h开始增高,于处理后72 h达到峰值。结论随着干旱程度的增加和胁迫的延长,金银花体内膜质过氧化严重,通过增加Pro、可溶性糖的含量以及保护酶系统来抵御干旱胁迫,保护酶启动顺序为CAT、SOD、POD、APX。     

3种根瘤菌对干旱和盐胁迫条件下穿心莲种子萌发的影响

目的:研究费氏中华根瘤菌、放射型根瘤菌和田菁茎瘤固氮根瘤菌对干旱和盐胁迫条件下穿心莲种子萌发的影响。方法:采用聚乙二醇6000(以下简称"PEG")和氯化钠(NaCl)浸种处理,分别建立穿心莲种子的干旱胁迫和盐胁迫模型。采用培养皿纸上发芽法,考察不同浓度PEG(0.05、0.10、0.15、0.20、0.25 g/mL)和NaCl(50、100、150、200 mmol/L)对穿心莲种子萌发指标(发芽率、发芽势、发芽指数、活力指数)的影响;分别采用费氏中华根瘤菌、放射型根瘤菌和田菁茎瘤固氮根瘤菌对穿心莲种子进行预处理后,同法考察其在干旱胁迫或盐胁迫条件下的各项萌发指标。结果:选取0.15 g/mL PEG溶液和50 mmol/L NaCl溶液分别构建穿心莲种子干旱胁迫和盐胁迫模型。费氏中华根瘤菌预处理可显著提高干旱胁迫条件下穿心莲种子的各项萌发指标以及盐胁迫条件下的发芽指数和活力指数,但同时可显著降低盐胁迫条件下的发芽率和发芽指数(P<0.05);放射型根瘤菌处理可显著提高干旱胁迫条件下穿心莲种子各项萌发指标以及盐胁迫条件下的发芽势、发芽指数和活力指数(P<0.05);田菁茎瘤固氮根瘤菌预处理可显著提高干旱胁迫条件下穿心莲种子的发芽率、发芽指数和活力指数以及盐胁迫条件下的发芽率和发芽势(P<0.05)。结论:3种根瘤菌处理均可在不同程度上改善穿心莲种子在干旱或盐胁迫条件下的发芽能力。本研究可为干旱条件下穿心莲的种植和栽培,以及将滩涂地区作为穿心莲的种植地提供技术支持。     

土壤水分有效性对梨枣叶片光合参数和抗旱性的影响--测试文章

利用自动称量和补水系统，对三年生梨枣树进行适宜水分、轻度和重度干旱三种土壤水分处理（土壤含水量分别为田间持水量的75%±5%、60%±5%和45%±5%），旨在探究不同土壤水分对梨枣叶片光合参数和抗旱性的影响。结果表明：(1) 轻度干旱对梨枣叶片的光合参数没有显著影响，但重度干旱引起净光合速率（Pn）、蒸腾速率（Tr）、气孔导度（Gs）、胞间CO₂浓度（Ci）和光能利用率（LUE）明显降低，而水分利用效率（WUE）和气孔限制值（Ls）增加。(2) 轻度干旱对梨枣叶片丙二醛（MDA）含量影响不大，过氧化氢酶（CAT）活性则显著上升；而重度干旱下MDA含量显著上升，同时超氧化物歧化酶（SOD）和过氧化物酶（POD）活性以及抗坏血酸（ASA）和还原型谷胱甘肽（GSH）含量明显升高，但仍不能消除重度干旱对梨枣叶片膜系统造成的严重伤害。因此，轻度干旱并未引发梨枣叶片显著的生物学胁迫，而在重度干旱条件下梨枣叶片的光合能力和膜系统均受到严重影响。     

神经生长因子对小鼠腹腔巨噬细胞SOD活性、MDA含量的影响

目的 研究神经生长因子（NGF）对正常小鼠、非肥胖性糖尿病（NOD）小鼠腹腔巨噬细胞过氧化物歧化酶（SOD）活性、丙二醛（MDA）含量的影响。方法 实验分对照组和实验组,用黄嘌呤氧化酶、TBA法检测细胞培养液中SOD活性、MDA含量。结果 与正常小鼠比较,NOD小鼠腹腔巨噬细胞SOD活性明显增高（P〈0．05）,MDA含量却明显减小（P〈0．01）;与各自对照组比较,NGF（5ng／ml、10ng／m1）实验组巨噬细胞SOD活性、MDA含量有显著改变。结论 糖尿病在病程的不同时期,SOD活性、MDA含量可以出现不同的变化,NGF对改善细胞代谢可能有一定影响。     

外源ABA浸种对冬油菜种子萌发及幼苗抗寒性的诱导效应

为探讨外源脱落酸(ABA)对北方寒旱区冬油菜幼苗抗寒性的诱导效应,试验分别用不同浓度的ABA对超强抗寒性白菜型冬油菜品种“陇油6号”和弱抗寒性品种“天油2号”进行浸种处理,研究不同浓度ABA浸种对冬油菜种子萌发及常温和低温胁迫条件下相关抗寒指标的影响。结果表明,10～70 mg·L^-1 ABA处理促进了种子萌发,80 mg·L^-1ABA处理对发芽率和发芽势有抑制作用;30 mg·L^-1浓度的ABA对冬油菜抗寒性诱导效果最佳,可显著（P＜0.05）提高冬油菜幼苗抗氧化酶（SOD、POD和CAT）活性,延缓叶绿素含量的降低,增加叶片脯氨酸含量,减缓膜脂过氧化产物丙二醛的积累;外源ABA处理在品种上存在差异,对抗寒性强的品种陇油6号效果明显。     

马齿苋水提物对阿尔茨海默病模型小鼠学习行为的干预作用

目的 观察马齿苋水提物对AlCl₃诱发阿尔茨海默病(Alzheimer’s disease,AD)模型小鼠学习行为及脑组织中超氧化物歧化酶(SOD)、乙酰胆碱酯酶(Acetyl cholinesterase,AchE)活性和丙二醛(MDA)浓度的影响。方法 小鼠随机分为2批6组,正常组、模型组、吡拉西坦(3.0 g·kg^-1)组、马齿苋水提物(2.6,1.3,0.65 g·kg^-1)组。正常组口服生理盐水,AlCl₃ 200 mg·kg^-1给药制备AD小鼠模型。连续造模和口服给药40 d。使用避暗仪和水迷宫仪,检测马齿苋水提物对AD模型小鼠的学习行为的变化,测定脑组织中MDA含量、SOD和AchE活性。结果 不同浓度马齿苋水提物明显延长小鼠避暗潜伏期,减少错误次数;缩短小鼠水迷宫到达时间和减少错误次数;明显升高脑组织SOD活性,降低AchE活性和MDA含量。结论 马齿苋对AD模型小鼠学习行为具有明显的改善作用,其作用可能与升高SOD活性,降低MDA含量和AchE活性有关。     

槲皮素对阿霉素致小鼠心肌损伤的保护作用及其机制

观察槲皮素对阿霉素致小鼠心肌损伤的保护作用并初步探讨其机制。腹腔注射阿霉素(20 mg·kg^-1)复制小鼠心肌损伤模型，检测心电图、心肌超微结构，血清NO含量和iNOS活性，心肌组织LDH、SOD、MDA的水平和p53蛋白表达。并观察槲皮素(50，100及200 mg·kg^-1)对上述指标的影响。阿霉素可导致小鼠心律失常和心肌超微结构损伤；使NO、iNOS、MDA和LDH的水平升高，SOD的水平降低；p53蛋白表达增强。槲皮素(50，100及200 mg·kg^-1)可拮抗阿霉素所致的上述变化。槲皮素对阿霉素性小鼠心肌损伤具有保护作用，其机制与增强SOD活力、降低iNOS活性、抑制p53蛋白表达等有关。     

局部根区水分胁迫下钙对冬小麦生长及养分吸收的影响--测试文章

以小偃22为材料，采用Hoagland营养液进行分根培养试验，研究了局部根区水分胁迫下，钙对冬小麦幼苗生长及养分吸收的影响。设置2个钙水平处理（正常供钙和不供钙）、3种水分处理（正常水分、局部根区水分胁迫和全部根区水分胁迫），共6个处理。结果表明：不论是否水分胁迫，缺钙处理冬小麦幼苗的株高、主根长、生物量、叶绿素相对含量（SPAD值）、相对含水量及地上部N、P、Ca含量和根系N、P、K、Ca含量均显著低于正常供钙处理(P＜0.05)。正常供钙条件下，局部根区水分胁迫使株高增加4.4%，正常水分、局部根区水分胁迫和全部根区水分胁迫的植株生物量分别为1.54、1.66 g·株^-1和0.97 g·株^-1，比缺钙处理分别高19.4%、25.8%和4.3%；全部根区水分胁迫下，冬小麦的株高及主根长均显著降低。缺钙条件下，植株对N、P、Ca等养分的吸收显著降低。正常供钙条件下，正常水分、局部根区水分胁迫和全部根区水分胁迫处理地上部全氮含量分别为36.54、36.65 g·kg^-1和32.70 g·kg^-1，比缺钙处理分别高9.5%、6.5%和6.9%；全磷含量分别为7.48、7.51 g·kg^-1和6.54 g·kg^-1，比缺钙处理分别高3.0%、13.1%和22.7%；全钙含量分别为8.35、8.37 g·kg^-1和5.53 g·kg^-1，比缺钙处理分别高26.5%、24.4%和19.7%。结果说明钙显著影响冬小麦幼苗生长发育和养分利用，钙可促进局部根区水分胁迫下冬小麦幼苗的生长及其对养分的吸收，缓解全部根区水分胁迫的抑制效应。     

中性盐和碱性盐胁迫对黑果枸杞种子萌发及幼苗生长的影响

在中性盐(NaCl)和碱性盐(Na₂CO₃)胁迫下,对采自河西走廊黑河中游的黑果枸杞进行种子萌发及幼苗生长试验,测定了发芽率(G_r)、发芽势(G_v)、发芽指数(G_I)、活力指数(V_I)和相对盐害率及幼苗的组织含水量、可溶性蛋白质含量、叶绿素含量、电导率、丙二醛含量和POD含量等指标。结果表明,黑果枸杞种子萌发的NaCl、Na₂CO₃浓度的临界值分别是50 mmol·L^-1和2.5 mmol·L^-1,极限值分别是300 mmol·L^-1和100 mmol·L^-1;在NaCl和Na₂CO₃胁迫下,发芽率分别为69.17%和71.67%;幼苗组织含水量分别由对照的88.97%降低到56.17%、70.27%;可溶性蛋白质含量最大值分别为7.09%、7.73%;叶绿素含量分别由对照的1.27 mg·g^-1降到0.78 mg·g^-1、0.92 mg·g^-1;电导率分别由对照的25.63%增加到64.77%、74.8%;丙二醛含量分别由对照的1.5 μmol·g^-1增加到6.9、6.5 μmol·g^-1;POD活性分别由对照的380.4 U·g^-1·min^-1降低到139.2 U·g^-1·min^-1、192.7 U·g^-1·min^-1。黑果枸杞是盐生植物,低浓度的盐促进萌发,高浓度的抑制萌发;碱性盐更适合其生长;黑果枸杞幼苗在盐胁迫下的生理响应及生态适应综合表现出黑果枸杞更适于碱性盐生长。     

用鲁米诺分子发光探针进行中草药微量铬的测定

鲁米诺是一种分子发光探针,在三价铬离子的存在下与过氧化氢可以产生化学发光,当实验条件恰当时,在一定的范围内三价铬离子浓度与化学发光强度成正比,将此测定原理应用于中草药微量铬的测定效果满意。     

镍作业工人外周血多形核中性粒细胞化学发光变化及硒的调节作用

用化学发光法研究镍对作业工人细胞免疫功能的影响，与非镍作业的地区对照组比较，镍作业工人外周血多形核中性粒细胞化学发光（ＰＭＮ－ＣＬ）的本底值降低（Ｐ＜０．０１），调理酵母多糖（ＯＺ）刺激诱发的ＰＭＮ－ＣＬ显著增高（Ｐ＜０．００１），＃ＦＫ提示镍对作业工人外周血ＰＭＮ－ＣＬ有不良影响．对镍作业工人补硒后，与平行对照组比较，补硒组ＰＭＮ－ＣＬ的本底值增高（Ｐ＜０．０１），受ＯＺ刺激诱发的ＰＭＮ－ＣＬ明显降低（Ｐ＜０．００１），且随补硒时间延长效果更显著，说明补硒能有效改善镍作业工人外周血ＰＭＮ－ＣＬ的异常变化；体外研究也证实了镍对ＯＺ刺激的人外周血化学发光的增强作用及硒的调节效果．     

时间分辨荧光法高通量筛选鱼肉组织中土霉素的残留量

目的动物组织中抗生素残留量的测定一般需要多步骤的样品处理过程。本文介绍了一种全新的、简便和快速筛选鱼肉中土霉素残留量的方法。采用固相萃取和时间分辨荧光(time resolved luminescence,TRL)技术,无须离心和过滤,简化了分析过程。方法将C18小片浸在组织匀浆液中提取和富集20min,取出,在水中浸泡3min,接着浸在TRL试剂溶液中2min,最后取出干燥。干燥后,在C18小片表面上直接进行荧光测定。结果土霉素在0~8μg/g的范围内,仪器信号的响应与浓度呈现良好的线性关系(γ2=0.9992),检测限为0.026μg/g,采用本法对45个加标准液的样品(浓度范围在0~4μg/g)进行分析,其中41个样品的定性结果正确,只有4个样品定性结果显假阳性。结论本方法简便,快速,准确,适用于鱼肉组织中土霉素的高通量筛选分析。     

检测肺癌患者胸腔积液中CEA及CA153的临床意义(附56例报告)

目的本研究拟通过检测肺癌患者血清和胸腔积液中癌细胞释放的癌蛋白,以弥补单纯细胞学检测的局限性,寻找一种更灵敏、准确的肺癌检测手段。方法采用电化学发光分析仪对56例肺癌患者及32例非肺癌患者的血清和胸腔积液进行了免疫蛋白定量分析。结果肺癌组明显高于非肺癌组内水平(P<0.01),CEA与CA153联合检测为最佳组合,其敏感性和特异性分别高达87.61%和97.8%。结论检测肺癌患者胸腔积液中CEA及CA153水平可能对肺癌的诊断具有重要的临床意义。     

Inhibition of Quorum Sensing in Vibrio harveyi by Boronic Acids

Bacterial quorum sensing refers to the ability of bacteria to control gene expression through the detection of a threshold concentration of certain chemicals called autoinducer(s), which are secreted by self and/or other bacteria. Quorum sensing is implicated in the regulation of pathologically relevant events such as biofilm formation, virulence, conjugation, sporulation, and swarming mobility. Inhibitors of bacterial quorum sensing are valuable research tools and potential antimicrobial agents. In this paper, we describe the discovery of several boronic acid inhibitors of bacterial quorum sensing in Vibrio harveyi with IC₅₀ values in the low to sub‐micromolar range in whole cell assays.     

Novel luminescence assay offers new possibilities for the risk assessment of silica nanoparticles

Recent opinions of the Scientific Committee on Consumer Products (SCCP) of the European Commission emphasize the missing validation of in vitro methodologies for nanomaterials and suggest that a review of the safety of insoluble nanomaterials presently used is required. Therefore the influence of Fluospheres® and silica nanoparticles, representing the class of organic and inorganic nanoparticles, respectively, on the lactate dehydrogenase (LDH) assay and the novel luminescence based Vialight® assay was tested. While LDH assay showed strong interactions with the tested silica particles, these problems may be overcome by novel methods like luminescence based assays. These findings suggest that even well characterized assay systems need a careful evaluation of the particle assay interactions when working with nanoparticles. Furthermore, particles based on the same material exhibit different biological properties depending on whether the material is used in micro- or nanometer range.     

Cerenkov luminescence imaging on evaluation of early response to chemotherapy of drug-resistant gastric cancer

Apoptosis imaging enables a timely and specific assessment of treatment response in cancer patients. In this study, we applied a probe for positron emission tomography (PET), which served as an optical biomaterial emitting Cerenkov photons, to in vivo optical imaging of tumor apoptosis, in order to evaluate early response to chemotherapy of drug-resistant gastric cancer. ⁶⁸Ga-DOTA-Annexin V was prepared as the apoptosis targeting probe. Wild type human gastric adenocarcinoma cell line SGC7901/WT and drug vincristine-resistant variant SGC7901/VCR were used to establish normal and vincristine-resistant xenografts to simulate treatment decision situation. Vincristine-resistance of SGC7901/VCR and apoptosis-induction ability of vincristine and cisplatin were verified. In vitro and in vivo CLI of apoptosis was performed. Stronger signals of apoptosis of CLI correlated with confirmed higher levels of apoptosis and subsequent changes in tumor sizes. Our study suggests that CLI is a promising technique for in vivo imaging of apoptosis with radiopharmaceutical-labeled biomaterials.     

Optimization of luminescent assay for screening of cyclin-dependent kinase 2 inhibitors

Cyclin-dependent kinases are most extensively studied targets for cancer chemotherapy since the tumor cells exhibit false checkpoints and can proliferate even if the genome is compromised. Cyclin-dependent kinases ensure the tight regulation of the cell cycle execution by mediating phosphorylation of cellular proteins. Deregulation of the cyclin-dependent kinase 2 activity by cellular and external factors leads to many diseases like cancers. Different methods like radiolabeled, fluorescence and luminescence are available for screening of library of compounds against kinases. However, bioluminescent methods offer several advantages like low background and no effect of fluorescent compound interference. Present study is focused on development, optimization and validation of cyclin-dependent kinase 2 assay which is suitable for identification potent and selective, ATP competitive and non-competitive inhibitors of cyclin-dependent kinase 2. The aim of present investigation was to optimize the assay for cyclin-dependent kinase 2/cylin A and cyclin-dependent kinase 2/cyclin E with use of bioluminescence based biochemical reaction. Both cyclin-dependent kinase 2 which are cyclin-dependent kinase 2/cyclin A and cyclin-dependent kinase 2/cyclin E complexes, have different affinity for ATP. Therefore, both isoform analogs of cyclin-dependent kinase 2 were optimized separately. Optimum cyclin-dependent kinase 2/cyclin A and cyclin-dependent kinase 2/cyclin E concentration were found to be 250 ng/well and 200 ng/well, respectively. Optimum substrate (histone H1) concentration was found to be 2.5 mg/ml for both cyclin-dependent kinase 2 analogs. Optimum reaction time was found to be 20 min for both cyclin-dependent kinase 2/cyclin complexes.     

Application of f--f luminescence of terbium ion for determination of non-steroidal anti-inflammatory drug-niflumic acid

A simple, rapid and sensitive luminescence method for determination of niflumic acid (NFA) is described. The method is based on the intramolecular energy transfer from niflumic acid to terbium ion (Tb³⁺) in the presence of trioctylphosphine oxide (TOPO). Optimum conditions for the formation of the NFA–Tb³⁺–TOPO ternary complex have been investigated. The calibration graph is linear over the range 0.002–0.02 μg ml⁻¹. The relative standard deviation is close to 4%. The recoveries obtained by applying the method to the analysis of urine ranged from 94–102%.     

镧系敏化发光技术快速筛检测定牛肉组织中丹诺沙星的残留量

建立了C18吸附提取(sorbent extraction)和固体表面时间分辨荧光(time resolved luminescence,TRL)技术,用于快速测定牛肉组织中丹诺沙星的残留量.将涂有C18吸附剂的玻璃片浸入除脂的组织匀浆液中提取和富集30 min后,浸入TRL反应试液中反应6 min,取出干燥后采用铽敏化发光技术(terbium-sensitized luminescence,TSL)在C18玻璃片表面直接进行荧光测定,激发光和发射光波长为273 nm和546 nm.丹诺沙星在0～1000ng/ g范围内线性良好.采用本法测定48个盲样(添加浓度为0～1000 ng/g),其中45个样品的测定结果正确,3个样品结果为假阳性.