保幼激素类似物对黄胸散白蚁兵蚁分化的诱导

本文报道保幼激素类似物诱导黄胸散白蚁兵蚁分化的作用。试验证明:用保幼激素类似物处理的滤纸喂食工蚁组成的实验群体,可以引起工蚁向前兵蚁方向分化,发生这种分化的工蚁数量最高达45%。三种保幼激素类似物具有明显的作用,它们是:3,7,11-三甲基十二碳-2,4-二烯酸乙酯、11-甲氧基-3,7,11-三甲基十二碳-2,4-二烯酸硫代乙酯和11-甲氧基-3,7,11-三甲基十二碳-2,4-二烯酸异丙酯。     

亚洲栽培稻与AA染色体组稻种的可交配性及F1杂种育性分析

从可交配性和F1杂种育性两方面对亚洲栽培稻与AA染色体组（以下简称AA组）其他7个稻种的系统关系进行了分析。结果表明：栽培稻籼、粳亚种与AA组不同稻种杂交均具有一定的结实率,可交配性不是影响亚洲栽培稻与其他AA组稻种间基因交流的主要生殖障碍。亚洲栽培稻与普通野生稻及尼瓦拉野生稻种间F1花粉育性和小穗育性有不同程度分化,与其他稻种的F1花粉育性和小穗育性均很低,F1杂种不育是AA组内基因交流的主要障碍。综合可交配性和F1小穗育性两方面的因素,初步得出：亚洲栽培稻与AA组稻种的亲缘关系由近及远依次是：普通野生稻、尼瓦拉野生稻、南方野生稻、展颖野生稻、非洲栽培稻、长雄蕊野生稻和短舌野生稻。其中普通野生稻和尼瓦拉野生稻是AA组中可直接利用于水稻育种的野生稻资源。     

水稻亚种间杂种小穗败育的细胞学基础

本文对普通栽培稻不同品种种类型间杂种小穗败育的细胞学基础及雌性败育的过程进行了研究,结果表明：（１）引起杂种小穗败育的原因有胚囊败育、花粉败育、开花时花药不开裂和雌雄异熟。其中胚囊败育而丧失受精能力是引起低结实率的最重要的因素,开花时花药不开裂和雌雄异熟在一定程度上形成了雌雄性细胞时间和空间的隔离屏障。     

转番茄几丁质酶基因西瓜植株的获得及其抗病性研究

构建了以CaMV35s启动子驱动的含有番茄几丁质酶基因（Chi3）的植物表达载体,通过冻融法导入根癌农杆菌（Agrobacterium tumefaciens）菌株EHAl05中。用叶盘法转化西瓜（Citrullus lanatus）栽培种“中育1号”,通过PCR、Southern blot和RT-PCR鉴定,表明外源基因已成功整合到西瓜基闪组中,并获得表达。利用尖孢镰刀菌西瓜专化型进行的转基因植株叶片粗提液抑菌效果检测,表明转基因植株的抗病性均有一定程度的增强。     

大白菜雄性败育的显微结构观察

通过对核质互作型雄性不育系169A和核雄性不育两用系88_3的细胞形态解剖学观察表明,两个不育系在开花时雄性细胞均表现100%的败育,花药的表皮细胞均具有生活力,但败育形式、时期、特点各异。169A败育发生于孢原细胞前后,以孢原细胞退化,或转变成薄壁细胞为主要特点。88_3败育从小孢子母细胞至二核花粉粒皆有发生,高峰期在四分体前后（约占80%）,小孢子母细胞不能进入减数分裂和不能完成减数分裂及小孢子不能正常发育是败育的主要形式,但败育特点均是败育一旦发生便是急剧而彻底的解体或凝集成一团。     

大白菜雄性败育的显微结构观察

通过对核质互作型雄性不育系169A和核雄性不育两用系88-3的细胞形态解剖学观 察表明,两个不育系在开花时雄性细胞均表现100%的败育,花药的表皮细胞均具有生活力,但败育形式、时期、特点各异。169A败育发生于孢原细胞前后,以孢原细胞退化,或转变成薄壁细胞为主要特点。88-3败育从小孢子母细胞至二核花粉粒皆有发生,高峰期在四分体前后（约占80%）,小孢子母细胞不能进入减数分裂和不能完成减数分裂及小孢子不能正常发育是败育的主要形式,但败育特点均是败育一旦发生便是急剧而彻底的解体或凝集成一团。     

赖氨酸月桂酯的抗菌活性及作用机制

<正> 一、氨基酸酯是一种具有抗菌活性的氨基酸衍生物,随着氨基酸的种类不同和烷基碳原子数目的不同,其抗菌活性也不相同。碱性氨基酸的十二烷基酯的抗菌作用最强。二、赖氨酸月桂基酯对金黄色葡萄球菌的呼吸作用具有抑制作用。对四种碳源和四种氮源的氧化抑制程度是不同的,在一定浓度条件下,抑制程度随赖氨酸月桂基酯的浓度增加而增加,但当赖氨酸月桂基酯浓度为25r/ml时,不仅对氧化基质没有抑制作用,反而促进金黄     

大白菜雄性不育系88—3花药和花粉发育的细胞形态学观察

大白菜雄怀不育两用系88－3的不育株,其开花时花药内无花粉粒,败育从小孢子母细胞至二核花粉粒皆有发生,高峰期在末期Ⅱ前后,小孢子母细胞不能进入减数分裂和小孢子母细胞不能完成减数分裂及孢子不能正常发育是雄性败育的主要形式;败育一旦发生便是急剧而彻底地解体或凝聚成一团是败育的共同点,中层组织、绒毡层组织及药隔维管束异常均是雄性败育的因素。     

农垦58s育性转换与吲哚乙酸氧化酶和过氧化物酶的关系

本文报道了农垦58s和农垦58幼穗发育期长短日下吲哚乙酸氧化酶和过氧化物酶的活性变化。结果表明:58s LD叶片中吲哚乙酸氧化酶活性从花粉母细胞形成期至花粉内容物充实期显著低于58s SD,与游离IAA的积累密切相关,可能影响花粉育性;但过氧化物酶的活性在上述时期显著高于58s SD,与游离IAA的积累无关,其作用尚不清楚。58s LD幼穗及花药中两酶活性在减数分裂期和花粉内容物充实期均较58s SD高,与同期幼穗及花药中游离IAA的亏缺有一定联系,从而可能在一定程度上影响花粉育性。对照农垦58叶片和幼穗及花药中两酶活性变化都不呈现上述现象。     

不同程度精索静脉曲张对不育男性精浆生化标志物及精子DNA完整性的影响

摘要 目的：探讨不同程度精索静脉曲张（varicocele,VC）对不育男性精浆生化标志物及精子DNA完整性的影响。方法：选取2017年8月至2020年9月至我院生殖医学中心男性专科门诊就诊并进行精浆生化及精子DNA完整性检查的不育患者138例,按照有无VC分为VC不育组62例,非VC不育组76例,选取同期就诊无VC的正常生育者60例作为本研究的对照组,根据精索静脉曲张程度将VC不育组患者分为VCⅠ度组、VCⅡ度组、VCⅢ度组。比较VC不育组、非VC不育组与正常生育组精浆生化标志物及精子DNA碎片率（DNA fragmentation index,DFI）,分析比较VC不育各亚组间精浆生化标志物及精子DFI变化情况。结果：精浆生化标志物分析：VC不育组精浆α-葡萄糖苷酶较非VC不育组及正常生育组明显减低（P＜0.05）,且VC不育各亚组间精浆α-葡萄糖苷酶水平依次减低,三组间两两比较有显著性差异（P＜0.05）;精浆锌、柠檬酸、果糖在VC不育组、非VC不育组与正常生育组比较无统计学差异（P＞0.05）,在VC不育各亚组间比较均无显著性差异（P＞0.05）;精子DFI分析：VC不育组精子DFI较正常生育组升高（P＜0.05）,非VC不育组精子DFI较正常生育组升高（P＜0.05）,VC不育组精子DFI较非VC不育组比较未见明显差异（P＞0.05）;VC不育各亚组间精子DFI逐渐升高,三组间两两比较精有显著性差异（P＜0.05）。结论：VC的发生与进展程度与精子DFI及精浆α-葡萄糖苷酶水平异常具有相关性,其二者可作为评价VC的有效指标,并为VC的分度提供一定的依据。     

Sodium Dodecyl Sulfate-Stable Proteases in Chloroplasts

Chloroplast subfractions were monitored for sodium dodecyl sulfate-stable proteases. Nine distinct activities in the molecular mass range from 14 to 66 kD have been detected. Five of the proteases associated with thylakoid membranes belong to the serine and cysteine types of proteases. These activities could be preserved and purified by a two-step electrophoresis procedure.     

海藻酸钠与十二烷基聚氧乙烯醚硫酸钠复配体系泡沫及流变性能的研究

采用罗氏泡沫仪和流变仪对海藻酸钠(NaAlg)/十二烷基聚氧乙烯醚硫酸钠(AES)复配体系的起泡稳泡性能及流变行为进行研究,以探索NaAlg对AES起泡稳定性的影响及作用机理。泡沫性能试验显示,NaAlg的加入,提高了AES溶液的起泡能力及泡沫稳定性,溶液的pH值由7.0降到5.0,混合体系的起泡稳泡性明显增加。流变性研究展示,随着NaAlg浓度的增加,溶液的粘度呈增大的趋势,溶液总体呈现牛顿流体性质,当NaAlg浓度大于0.5%时,低剪切速率区,溶液仍呈现牛顿流体性质,而在高剪切速率区,有剪切变稀的现象出现。总体来看,各试液的G’相似文献   

Monomeric Creatine Kinase Aggregation and Sodium Dodecyl Sulfate-cyclodextrin Assisted Refolding

Abstract

The monomelic state of creatine kinase (CK) was stably captured at the equilibrium state by employing cysteine residue modifications in the presence of a dénaturant, and at a partially folded state. The partially folded monomeric CK (PF-CK) was aggregated with kinetic order, which was mainly caused by the hydrophobic surface interactions between the CK subunits. The artificial chaperone, described as a SDS-cyclodextrin, was applied to prevent aggregation as well as to refold the PF-CK: SDS treatment onto the monomeric CK can significantly block aggregation and can be successfully refolded in the solutions containing cyclodextrins and DTT. Three types of cyclodextrins such as α-, β-, and γ-cyclodextrins were applied to strip SDS from the enzyme molecule, and each kinetic course was measured. The intrinsic fluorescence changes showed that reactivation occurred and this accompanied the conformational changes. The size exclusion chromatography detected the variously trapped monomeric CKs such as the thiol residue modified PF-CK, the SDS- binding PF-CK, the cyclodextrin treated PF-CK, and the DTT treated SDS-binding PF-CK. Our study demonstrated monomer CK aggregation for the first time; we also demonstrated the complex reassociation of CK during refolding with the aid of the SDS-cyclodextrin, and these pathways followed first-order kinetics.     

Enzymes Induced in a Bacterium by Growth on Sodium Dodecyl Sulfate

Alkyl sulfatase was induced by growth on nutrient broth plus sodium dodecyl sulfate (SDS) in a bacterium we have designated Pseudomonas C12B. Measurement of the radioactivity of S³⁵O₄⁼ released from SDS³⁵ by the enzyme in cell-free extracts provided an effective assay technique. The barium chloranilate assay for release of SO₄⁼ from SDS was somewhat less sensitive but effective if analyzed at 332 mμ. This test was only approximately 55% as sensitive if analyzed at 530 mμ. The activity of the glyoxylate bypass enzymes, isocitrate lyase and malate synthetase, was significantly stimulated by growth of the bacteria on SDS as the sole carbon source, but not by growth on nutrient broth or nutrient broth plus SDS.     

An Analysis of the Interaction of Sodium Dodecyl Sulfate with Lysozyme

The interaction of SDS with lysozyme was analyzed with enzyme activity and with NMR, fluorescence, and UV difference spectroscopies using various alkyl sulfates and variously modified lysozymes. SDS formed a stable complex with lysozyme without causing a gross conformational change in the enzyme molecule. Some SDS molecules bound to the active site cleft of lysozyme and therefore strongly inhibited the activity of lysozyme. Hydrophobic regions and positive charges for protein side, and a hydrophobic tail (possibly more than 8 carbons in alkyl chain) and a negative charge for detergent side were required for the formation of the complex.     

Sodium Dodecyl Sulfate-Polyacrylamide Gel Protein Electrophoresis of Freshwater Photosynthetic Sulfur Bacteria

Sodium dodecyl sulfate-polyacrylamide gel protein electrophoresis (SDS-PAGE) was carried out using different bacterial strains of the photosynthetic sulfur bacteria Chlorobium, Thiocapsa, Thiocystis, and Chromatium cultured in the laboratory, and the natural blooms in two karstic lakes (Lake Cisó and Lake Vilar, NE Spain) where planktonic photosynthetic bacteria (purple and green sulfur bacteria) massively developed accounting for most of the microbial biomass. Several extraction, solubilization, and electrophoresis methods were tested to develop an optimal protocol for the best resolution of the SDS-PAGE. Protein composition from different water depths and at different times of the year was visualized within a molecular mass range between 100 and 15 kDa yielding up to 20 different protein bands. Protein banding patterns were reproducible and changed in time and with depth in agreement with changes in photosynthetic bacteria composition. When a taxonomically stable community was followed in time, differences were observed in the intensity but not in the composition of the SDS-PAGE banding pattern. Three environmental variables directly related to the activity of sulfur bacteria (light, oxygen, and sulfide concentrations) had a significant effect on protein banding patterns and explained 33% of the variance. Changes in natural protein profiles of the bacterial blooms agreed with changes in species composition and in the in situ metabolic state of the populations.     

Non-Immunological Precipitation of Serum by Sodium Dodecyl Sulfate in Agar Diffusion

Marmoset serum or serum of other species of animal may react with sodium dodecyl sulfate and forms nonspecific precipitin lines in agar diffusion. The protein detergent complexes are not readily dialyzable. Therefore precipitin lines derived from studies that use sodium dodecyl sulfate-treated antigens in agar diffusion must be interpreted with caution.     

十二烷基硫酸钠对斑马鱼抗氧化能力的影响

以斑马鱼Brachyclanio rerio为实验对象,用不同浓度(0.5、3.0、18.0mg/L)的阴离子表面活性剂十二烷基硫酸钠(SDS)进行3、14、28、42、63d的暴露实验,通过测定肌肉组织中的总抗氧化能力(TAC)、超氧化物歧化酶(SOD)活性及丙二醛(MDA)含量三项指标研究SDS对斑马鱼抗氧化能力的影响。结果表明:0.5mg/L和3.0mg/L实验组SOD活性受到显著抑制(P<0.05),TAC水平和MDA含量与对照组无显著差异;18.0mg/L实验组在TAC水平和SOD活性上均表现为显著降低(P<0.05或P<0.01),MDA含量较对照和低剂量组亦有较大幅度增加,显示该组受试个体的抗氧化能力受到了显著抑制。研究结果对评价水环境中SDS毒性生物效应具有参考意义。     

Specific Staining of Sialic Acid Components on Sodium Dodecyl Sulfate Polyacrylamide Gel

Specific staining of sialic acid components after sodium dodecyl sulfate polyacrylamide gel electrophoresis can be carried out as follows: 1) extract glycoprotein of erythrocyte membranes or serum by the phenol-saline method, 2) electrophorese the extract on 5% polyacrylamide gel containing 0.1% sodium dodecyl sulfate at constant current, 3) treat the gel with chilled 0.04 M HIO₄ for 45 minutes, 4) replace the periodic acid solution with one containing resorcinol 0.6 g, cone. HCl 50 ml, 0.1 M CuSO₄ 0.5 ml and H₂O 50 ml, 5) warm the container in boiling water until blue violet sialic acid bands become clear, 6) replace the staining solution with a mixture of equal parts water and concentrated HCl and observe at once.