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1.
达乌尔黄鼠产热的季节性变化   总被引:4,自引:2,他引:4  
达乌尔黄鼠(Citellusdauricus)的产热表现出明显的季节性变化。在非冬眠期,静止代谢率(RMR)和非颤抖性产热(NST)于春季最高,秋季次之,夏季最低。冬眠期,RMR降到极低水平,只为春季的3.0%。肝脏的线粒体蛋白含量、线粒体呼吸和细胞色素C氧化酶活力在秋季显著高于其它各季。褐色脂肪组织(BAT)的重量、线粒体蛋白含量、细胞色素C氧化酶活力和α-磷酸甘油氧化酶活力,在夏季处于一年中的最低水平,到了冬季这些指标达到一年中的最高水平。在非冬眠季节BAT产热能力升高时,NST能力也相应升高,这表明BAT产热能力的增强是NST能力提高的部分机制。达乌尔黄鼠血清T_4含量在年周期中没有明显改变,冬眠时血清T_3含量显著高于其它各季。  相似文献   

2.
非冬眠期达乌尔黄鼠对低温的适应性产热   总被引:1,自引:1,他引:0  
达乌尔黄鼠在夏季冷驯化低温环境下(5±1℃)暴露4周后,导致脂肪积累的抑制;其静止代谢率(RMR)和非颤抖性产热(NST)分别提高了12%和85%;肝脏线粒体的蛋白含量、状态3呼吸和细胞色素C氧化酶活力分别提高了22%、42%和48%,表明在低温环境下肝脏线粒体产热能力的增强是RMR提高的细胞学机制之一;褐色脂肪组织(BAT)的重量、蛋白含量、细胞色素C氧化酶活力和α-磷酸甘油氧化酶活力极显著提高,表明在低温环境下BAT是达乌尔黄鼠的主要产热器官,BAT产热能力的增强是NST提高的重要细胞学机制之一。冷驯化没有引起达乌尔黄鼠血清T3、T4含量的变化  相似文献   

3.
决明组织培养的研究   总被引:1,自引:0,他引:1  
以草决明无菌苗子叶为外植体,接种于7类诱导愈伤组织的培养基上:A.MS+2.02,4-Dmg/L(以下单位省略)+0.3BA+0.2NAA.B.MS+0.22,4-D十0.2BA+2.0NAA.C.MS+1.02,4-D+0.5BA+0.2KT.D.MS+0.7BA+1.5NAA+0.1KT.E.MS+1.52,4-D+0.7BA十0.2MAA.F.MS+0.42.4-D+1.0NAA+0.1KT.G.MSB(MS的无机成份和B5有机成分)+0.15NAA+BA,KT和ZT各0.5。8~15天后分别有90~99.6%的子叶片被诱导出愈伤组织,并且F.与C.类培养基对诱导愈伤组织比较理想,放于G培养基上的愈伤组织有9.2~30.2%的芽分化率。芽在生根培养基1/2MS+0.2IBA中、98%生根,形成完整的再生植株。  相似文献   

4.
宫粉郁金的组织培养和快速繁殖   总被引:8,自引:1,他引:7  
1植物名称宫粉郁金(Curcuma kwangsiensis)。2材料类别 块茎萌动芽。3培养条件 萌动芽生长培养基:(1)MS+6-BA1mg·L-1(单位下同)+NAA0.2。不定芽增殖与愈伤组织诱导培养基:(2)MS+6-BA10+KT5;(3)MS+6.BA10;(4)MS+6-BA5+KT2.5;(5)MS+6-BA5;(6)MS+6-BA2+KT1。生根培养基:(7)MS+NAA0.5;(8)MS+6-BA0.5+NAA0.5;(9)MS。以上培养基均加0.7%琼脂,3%蔗糖,pH5…  相似文献   

5.
矮生鸡冠花的离体快繁及试管苗开花   总被引:4,自引:0,他引:4  
1植物名称矮生鸡冠花(Celosiacristata)。2材料名称无菌种子苗顶芽、腋芽。3培养条件基本培养基为MS。培养基组合为:(1)MS+BA1-2mg·L~(-1)(单位下同)+NAA0.1~0.2;(2)MS+BA2+IAA0.2;(3)MS+KT2;(4)MS+BA0.1~0.5。以上培养基均含3%蔗糖,0.6%琼脂,pH为5.8,培养温室为(26±2)℃,光照12h.d~(-1)(2000lx)。4生长与分化情况4.1无菌材料的获得成熟的种子置70%酒精中摇动50s后,转入饱和漂白粉溶…  相似文献   

6.
倭蜂猴的产热及细胞呼吸特征   总被引:5,自引:2,他引:3  
倭蜂猴的最大非颤抖性产热较低,但占调节性产热的比例。交高;褐色脂肪组织BAT)重量也较其他灵长类大,产热生也较强;肝脏线粒体氧化能力较低,与其具有较低的BMR和体温波动较大有关。倭蜂猴相对较低的MST和低水平的RMR对其凭许性和节约能量极为有利。  相似文献   

7.
玫瑰海棠的组织培养及快速繁殖   总被引:16,自引:0,他引:16  
1植物名称玫瑰海棠(Begonnia mannii)。2材料类别幼芽、叶片。3培养条件以MS为基本培养基。诱导丛生芽培养基:(1)MS+KT1.0mp·L-1(单位下同)+NAA0.1。丛生芽增殖培养基:(2)MS+KT1.0+NAA0.05;(3)MS+6-BA0.5+NAA0.05。诱导生根培养基:(4)1/2MS+NAA0.2。上述培养基均加3%蔗糖,0.8%琼脂,pH5.8。培养温度(26±2)℃,光照度约为2000lx,光照14h·d-1。4生长与分化情况4.1无菌材料的获得将玫瑰海棠…  相似文献   

8.
本实验旨在观察肾动脉内注射ET-1对麻醉大鼠血压(BP)、心率(HR)和肾神经传入放电(ARNA)的影响,以及ETA受体阻断剂BQ-123和硝苯吡啶(Nif)对ET生物学效应的拮抗作用。结果如下:(1)肾动脉注射ET-1(1μg/kg)后,平均动脉压(MAP)先有短暂的降低(由13.77±0.13kPa降至10.2±1.12kPa),随后为较显著的持久增高,增值达3.44±1.60kPaP<0.001),HR无明显变化,ARNA增加108.33±16.67%(P<0.001)。(2)肾动脉内注射ETA受体选择性拮抗剂BQ-123(150μg/kg),ET-1的上述效应即被拮抗。与ET组相比差异非常显著(P<0.001)。(3)肾动脉内注射二氢吡啶敏感性L-型钙通道阻断剂Nif(0.1mg/kg),也可明显抑制ET-1的上述效应,与ET组相比差异十分显著(P<0.001)。以上结果表明:肾动脉内注射ET-1引起的麻醉大鼠MAP增高和ARNA积分增加的作用,可能是由ETA受体介导的,其作用的细胞机制可能在于胞内钙超载  相似文献   

9.
在637例临床拟诊与待排肺结核的细菌学检测中,加做结核菌L型(TB-L)检测,结果痰、胸水、支气管肺泡灌洗液(BALF)浓缩涂片及支刷的阳性率分别从23.3%、13.5%、33.3%、42.2%提高到34.2%、28.9%、53.3%及62.3%。痰、胸水和BALF液体培养阳性率分别从45.0%、26.9%、66.7%提高至57.9%、46.1%和82.2%。显著高于单纯结核菌细菌型(TB-B)检测(p<0.001),使常规方法检测不出的135例单独TB-L感染肺结核得到确诊。分析该组病例因临床和胸片表现不典型,PPD试验不敏感,漏诊和误诊率高达84.4%。且化疗效果差。  相似文献   

10.
植物油对虫霉菌液体培养与保存的作用*   总被引:1,自引:1,他引:0  
许谦  冯明光 《菌物学报》2001,20(1):79-86
在萨氏营养液(SDB)中加入用 0.1%蔗糖脂肪酸酯-15(SE15)乳化的0.50%芝麻油,可使在SDB中生长慢而结块的新蚜虫疠霉、安徽虫瘟霉、飞虱虫疠毒和根虫瘟霉等四种虫霉的五个菌株形成均匀分散的菌丝体和能稳定转接的菌液。在SDB中加入乳化芝麻油 ( 0.25%~1.5%)、菜籽油( 0.50%~1.5%)和色拉油( 80%花生油和 20%菜籽油,0.75%~1.5%),能明显提高新蚜虫疠霉F98018的生物量;而在SDB中加入0.50%乳化芝麻油,可使液培菌丝产孢量增加近一倍;在SDB中加入的三种植物油(0.75%),在F98018生长4d后,含量分别下降了85%~94%,但其中脂肪酸相对组成基本不变,表明该菌生长能充分利用植物油中各脂肪酸。用萨氏培养基( SDAY)、加入 0.50%乳化芝麻油的 SDAY( OS-SDAY)和牛奶蛋黄培养基(SEMA)培养安徽虫瘟霉F97028和新蚜虫疠霉F98028,两菌株在SEMA上生长最快;在OS-SDAY以较慢速度正常生长;而在SDAY上,两菌株或不能生长,或在第二次培养时出现明显退化。用SEMA和OS-SDAY在3℃下来保存上述四种虫霉的七个菌株,在OS-SDAY上?  相似文献   

11.
Preparations, XPS and electronic spectroscopy, and magnetism of seven new one-dimensional cyano-bridged coordination polymers, chiral [Cu(RR-chxn)2][Pd(CN)4] · 2H2O (1), [Cu(trans-chxn)2][M(CN)4] · 2H2O (2, 4, and 6 for M = Pd, Ni, and Pt), and [Cu(cis-chxn)2][M(CN)4] · 2H2O (3, 5, and 7 for M = Pd, Ni, and Pt) (RR-chxn = cyclohexane-(1R,2R)-diamine, trans-chxn = racemic trans-cyclohexane-(1,2)-diamine, and cis-chxn = racemic cis-cyclohexane-(1,2)-diamine) have been reported in view of tuning of their electronic properties by stereochemistry of chxn ligands and metal-substitution. Comparison of Cu 2p1/2 and 2p3/2 peaks of XPS and broad d-d bands around 18 000 cm−1 of electronic spectra are described systematically for 1-7. Variable-temperature magnetic measurement shows that complexes 1-7 indicate weak antiferromagnetic interactions via cyano-bridges. Because of semi-coordination coupled with pseudo Jahn-Teller elongation and electrostatic interaction for 1, the axial Cu-N coordination bond distances of 2.330(7) and 3.092(8) Å are considerably longer than those of equatorial ones in the range from 2.016(6) to 2.030(6) Å. The former bond distances of 1 are intermediate values among the related Ni (2.324(6) and 3.120(8) Å) and Pt (2.34(1) and 3.09(1) Å) complexes.  相似文献   

12.
Over the past 10 years, Ghusel VDC, Lalitpur District has moved from primarily subsistence agriculture into the wider cash economy aided by the Small Farmers' Development Program (SFDP), which provides credit to farmers mainly for the purchase of buffalo for milk production, and by the National Dairy Corporation, which supports local dairy cooperatives. Analysis reveals that buffalo-keeping and milk sales are increasing the well-being of many households, while at the same time creating new inequalities in gender roles and responsibilities, greater inequities between Brahmin and Tamang residents in Ghusel, and placing pressures on the ecosystem for increased supplies of fodder and fuelwood. Evidence suggests that there is critical, need for attention to the social, and particularly gender-based, implications of maintaining livestock for milk sales and to the ecological underpinnings of this livelihood system.  相似文献   

13.
Structure and function of S-adenosylhomocysteine hydrolase   总被引:6,自引:0,他引:6  
In mammals, S-adenosylhomocysteine hydrolase (AdoHcyase) is the only known enzyme to catalyze the breakdown of S-adenosylhomocysteine (AdoHcy) to homocysteine and adenosine. AdoHcy is the product of all adenosylmethionine (AdoMet)-dependent biological transmethylations. These reactions have a wide range of products, and are common in all facets of biometabolism. As a product inhibitor, elevated levels of AdoHcy suppress AdoMet-dependent transmethylations. Thus, AdoHcyase is a regulator of biological transmethylation in general. The three-dimensional structure of AdoHcyase complexed with reduced nicotinamide adenine dinucleotide phosphate (NADH) and the inhibitor (1′R, 2′S, 3′R)-9-(2′,3′-dihyroxycyclopenten-1-yl)adenine (DHCeA) was solved by a combination of the crystallographic direct methods program, SnB, to determine the selenium atom substructure and by treating the multiwavelength anomalous diffraction data as a special case of multiple isomorphous replacement. The enzyme architecture resembles that observed for NAD-dependent dehydrogenases, with the catalytic domain and the cofactor binding domain each containing a modified Rossmann fold. The two domains form a deep active site cleft containing the cofactor and bound inhibitor molecule. A comparison of the inhibitor complex of the human enzyme and the structure of the rat enzyme, solved without inhibitor, suggests that a 17° rigid body movement of the catalytic domain occurs upon inhibitor/substrate binding.  相似文献   

14.
Chemical warfare nerve agents (CWNAs) are extremely toxic organophosphorus compounds that contain a chiral phosphorus center. Undirected synthesis of G‐type CWNAs produces stereoisomers of tabun, sarin, soman, and cyclosarin (GA, GB, GD, and GF, respectively). Analytical‐scale methods were developed using a supercritical fluid chromatography (SFC) system in tandem with a mass spectrometer for the separation, quantitation, and isolation of individual stereoisomers of GA, GB, GD, and GF. Screening various chiral stationary phases (CSPs) for the capacity to provide full baseline separation of the CWNAs revealed that a Regis WhelkO1 (SS) column was capable of separating the enantiomers of GA, GB, and GF, with elution of the P(+) enantiomer preceding elution of the corresponding P(–) enantiomer; two WhelkO1 (SS) columns had to be connected in series to achieve complete baseline resolution. The four diastereomers of GD were also resolved using two tandem WhelkO1 (SS) columns, with complete baseline separation of the two P(+) epimers. A single WhelkO1 (RR) column with inverse stereochemistry resulted in baseline separation of the GD P(–) epimers. The analytical methods described can be scaled to allow isolation of individual stereoisomers to assist in screening and development of countermeasures to organophosphorus nerve agents. Chirality 26:817–824, 2014. © 2014 The Authors. Chirality published by John Wiley Periodicals, Inc.  相似文献   

15.
The aim of the study has been to determine and compare the influence upon the kidney antioxidative system, exercised by administration of vitamin E, and vitamin E in combination with methionine, under conditions of oxidative stress induced by sodium fluoride. The experiment was carried out on Wistar FL rats (adult males) that, for 35 days, were administered water, NaF, NaF with vitamin E, or vitamin E with methionine (doses: 10 mg NaF/kg of body mass/24 h, 3 mg vitamin E per 10 μl per rat for 24 h, 2 mg methionine per rat for 24 h). The influence of administered sodium fluoride and antioxidants upon the antioxidative system in kidney was examined by analyzing the concentration of malondialdehyde (MDA) and the activity of the most important antioxidative enzymes (SOD, total and both its isoenzymes, GPX, GST, GR, and CAT). The studies carried out confirmed the disadvantageous effect of the administered dose of NaF upon the antixodiative system in rats (increase in the concentration MDA, decrease activity of all antioxidative enzymes). The administration of vitamin E increased the activity of studied enzymes with the exception of glutathione reductase GR; it also reduced the procesess of lipid peroxidation. It has been found that combined doses of vitamin E and methionine were most effective in inhibiting lipid peroxidation processes. The results confirmed the antioxidative properties of methionine.  相似文献   

16.
Auxin-mediated elongation growth of isolated subapical coleoptile segments of maize (Zea mays L.) is controlled by the extensibility of the outer cell wall of the outer epidermis (Kutschera et al., 1987). Here we investigate the hypothesis that auxin controls the extensibility of this wall by changing the orientation of newly deposited microfibrils through a corresponding change in the orientation of cortical microtubules. On the basis of electron micrographs it is shown that cessation of growth after removal of the endogenous source of auxin is correlated with a relative increase of longitudinally orientated microfibrils and microtubules at the inner wall surface. Conversely, reinduction of growth by exogenous auxin is correlated with a relative increase of transversely orientated microfibrils and microtubules at the inner wall surface. These changes can be detected 30–60 min after the removal and addition of auxin, respectively. The functional significance of directional changes of newly desposited wall microfibrils for the control of elongation growth is discussed.  相似文献   

17.
Mycobacterium tuberculosis (M.tb.), the causative agent of tuberculosis (TB), cannot synthesize GSH, but synthesizes two major low molecular weight thiols namely mycothiol (MSH) and ergothioneine (ERG). Gamma-glutamylcysteine (GGC), an intermediate in GSH synthesis, has been implicated in the protection of lactic acid bacteria from oxidative stress in the absence of GSH. In mycobacteria, GGC is an intermediate in ERG biosynthesis, and its formation is catalysed by EgtA (GshA). GGC is subsequently used by EgtB in the formation of hercynine-sulphoxide-GGC. In this study, M.tb. mutants harbouring unmarked, in-frame deletions in each of the fives genes involved in ERG biosynthesis (egtA, egtB, egtC, egtD and egtE) or a marked deletion of the mshA gene (required for MSH biosynthesis) were generated. Liquid chromatography tandem mass spectrometry analyses (LC-MS) revealed that the production of GGC was elevated in the MSH-deficient and the ERG-deficient mutants. The ERG-deficient ΔegtB mutant which accumulated GGC was more resistant to oxidative and nitrosative stress than the ERG-deficient, GGC-deficient ΔegtA mutant. This implicates GGC in the detoxification of reactive oxygen and nitrogen species in M.tb.  相似文献   

18.
The mitogenic responses of separated rabbit lymphocyte populations functionally analogous to mouse T and B cells have been tested in vitro. Purified T cells were prepared by passage over nylon wool (NW) and purified B cells prepared by treatment with antithymocyte serum and complement (ATS + C). ATS + C kills 70% of peripheral blood lymphocytes (PBL's) and 50% of the spleen cells while passage over NW yields 40% of the applied PBL's and 5–23% of the applied spleen cells. NW-purified T cells from the spleen or PBL's respond fully to concanavalin A (Con A) but have a reduced response to phytohemaglutinin (PHA) and little or no response to goat anti-rabbit immunoglobulin (anti-Ig). PBL's that survive ATS + C (B cells) are stimulated by anti-Ig but not by Con A or PHA. B cells purified from spleen do not respond to Con A or PHA but will respond to anti-Ig under appropriate conditions. A full spleen B-cell response to anti-Ig required removal of Ig produced by the cultures that blocked anti-Ig stimulation. It is concluded that, for rabbit lymphocytes, Con A and PHA are primarily T-cell mitogens and that anti-Ig is primarily a B-cell mitogen. However, the mitogen response of unfractionated PBL or spleen cell populations indicates an overlap in reactivity. This could be due to cells sharing T and B properties, alteration of cell populations by the fractionation procedures used, or recruitment of one population in the presence of a mitogenic response of the other population.  相似文献   

19.
八种脑-肠肽侧脑室内注射对大鼠基础胃酸分泌的影响   总被引:1,自引:0,他引:1  
用乌拉坦麻醉大鼠作急性实验,采用连续灌流胃并收集流出液的方法,观察向侧脑室内注射微量脑-肠肽对大鼠基础胃酸分泌的影响。实验结果如下:(1)雨蛙肽、八肽胆囊收缩素、促甲状腺素释放激素及四肽胃泌素均使总酸排出量增加;(2)生长抑素、胰多肽、P 物质、胰高血糖素则使总酸排出量减少;(3)上述肽类用侧脑室注射的剂量作肌肉注射,除四肽胃泌素也产生明显的刺激胃酸分泌作用外,对胃酸分泌均无明显影响。以上结果提示,脑内的一些肽类可能以神经递质或调制物的方式,参与中枢对胃酸分泌的调节。  相似文献   

20.
In this paper, a kind of Typhaceae plant species, Typha angustifolia L, with a high tolerance to Cr is described. Experiments were carried out to examine its ability to tolerant Cr and its physiological response. The results showed that there was no difference in growth, plant height, and biomass response to external Cr (VI) between the plants exposed to 100 microM Cr (VI) and control (0 microM), while increasing Cr levels to 200-800 microM induced a significant decrease in plant height and biomass, but no significant injury was detected, even for the plants exposed to 800 microM Cr. Chromium induced significant increases in superoxide dismutase (SOD) and peroxidase (POD) activities. Meanwhile, a significantly positive correlation was found between Cr and Mn or Cu in leaves and roots, respectively. The Cr tolerance of the plant appeared to be associated with the enhancement of SOD and POD activities and the improvement in uptake and translocation of the essential microelements.  相似文献   

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