不同因子对花鲈胚胎干细胞增殖的影响   总被引：2，自引：1，他引：2  

叶寒青 《水产学报》2004,28(5):493-498

胚胎干细胞(ES细胞)是从动物早期发育胚胎中分离出来的具有发育全能性的一种未分化细胞系。维持花鲈胚胎干细胞(LJES1)的体外生长、增殖及未分化状态需要在培养基中添加一些生长因子。实验通过配制省略1种或多种因子的培养基PESM0～10，计数LJES1细胞在各培养基中增殖的数量，确定各种生长因子对LJES1细胞的增殖作用。同时，对LIF因子和bFGF因子的作用进行了重点的研究，发现LIF因子对早期的LJES1细胞增殖几乎没有作用，其主要作用是维持LJES1细胞的未分化状态，但对晚期LJES1细胞的增殖有一定的作用；bFGF因子对LJES1细胞有强烈的刺激增殖的作用；鲈鱼胚胎抽提液(PEE)以及鲈鱼血清(FS)也促进了LJES1细胞的增殖，2-巯基乙醇(2-ME)具有还原血清中的含硫化合物、防止过氧化物对LJES1细胞的损害及促进贴壁的作用，因而也促进了LJES1细胞的增殖。  相似文献   

A systematic review of sevoflurane and isoflurane minimum alveolar concentration in domestic cats     

Mike R Shaughnessy  Erik H Hofmeister 《Veterinary anaesthesia and analgesia》2014,41(1):1-13

ObjectiveThe purpose of this systematic review is to summarize the results of studies which have determined the minimum alveolar concentration (MAC) of isoflurane and sevoflurane in domestic cats.Study DesignSystematic review.AnimalsCats.Methods usedA comprehensive search of research literature was performed without language restriction. The search utilized the Pubmed, Google Scholar, and CAB Abstracts electronic databases using a combination of free text terms ‘Minimum alveolar concentration’, ‘sevoflurane’, ‘isoflurane’, ‘anesthetic’, ‘cat’, ‘cats’ or ‘feline’. The search was conducted from November 2010 to June 2012.ResultsThe MAC for isoflurane ranged from 1.20 ± 0.13% to 2.22 ± 0.35% and the MAC for sevoflurane ranged from 2.5 ± 0.2% to 3.95 ± 0.33%. The average MAC for isoflurane was 1.71 ± 0.07% and for sevoflurane was 3.08 ± 0.4%.Conclusions &; Clinical RelevanceThe average MAC for isoflurane was 1.71 ± 0.07% and for sevoflurane was 3.08 ± 0.4%. Methodology differed among studies, and particular attention should be paid in the future to appropriate reporting of methods to allow sound conclusions to be made from the results.  相似文献   

双峰驼乳和牛乳中长链多不饱和脂肪酸质量浓度测定     

钱浩  ;陆东林  ;徐敏  ;叶东东 《中国乳业》2014,(12):63-66

采用国标法检测8份新疆双峰驼乳和7份荷斯坦牛乳中5种长链多不饱和脂肪酸的质量浓度和质量分数。结果表明：新疆双峰驼乳中亚油酸（LA）、α-亚麻酸（ALA）、花生四烯酸（ARA）、二十碳五烯酸（EPA）和二十二碳六烯酸（DHA）的平均质量浓度分别为142.99、18.09、9.83、1.51和1.30 mg/100 g,各种脂肪酸占总脂肪酸的比率依次为2.88%、0.37%、0.20%、0.031%和0.026%;荷斯坦牛乳中LA、ALA、ARA、EPA和DHA的平均质量浓度分别为88.37、5.13、6.57、0.69和4.24 mg/100 g,各种脂肪酸占总脂肪酸的比率依次为2.86%、0.17%、0.21%、0.023%和0.14%。  相似文献   

温度和食物对褶皱臂尾轮虫种群增长及繁殖的影响     

董婧  于业辉  赵莹莹  卫侃韵  高海钰  李林 《现代畜牧兽医》2014,(4):35-39

本试验设3个温度（20、25和30℃）和3个食物浓度（1×106、10×106和20×106 cells/mL）,研究不同温度和不同食物浓度对褶皱臂尾轮虫种群增长及繁殖的影响。试验期为10 d。结果表明,最大种群密度均随温度和食物浓度的升高而先增加后减少。温度为25℃食物浓度为10×106 cells/mL时,最大种群密度为74.39±1.81 ind/mL,与其他组比差异显著（P〈0.05）。随温度升高,轮虫的最大种群密度高峰值出现的时间也呈现逐渐前移的趋势,最大种群增长率则随温度和食物浓度的增加而升高。温度30℃食物20×106 cells/mL时,最大种群增长率为0.70±0.013,与其他组比差异显著（P〈0.05）。食物浓度对轮虫的怀卵率有显著影响,在同一温度下最大怀卵率随食物浓度的升高而增大,食物为20×106 cells/mL的最大怀卵率为56.43±1.07%,与其他浓度组比差异显著（P〈0.05）。在本试验条件下,温度和食物对褶皱臂尾轮虫的种群增长及繁殖均有显著影响。温度25℃食物浓度10×106 cells/mL为培养条件的最优组合。  相似文献   

三种有毒物质对文蛤的毒性试验   总被引：4，自引：1，他引：4  

孙国铭  于志华 《水产养殖》1997,(1):17-19

在常温和静水条件下，用通常的生物毒性试验方法进行了Ｈ２Ｓ、Ｚｎ、ＮＨ３对文蛤的急性毒性试验，求出了它们对３．６０￣３．７４厘米体长文蛤的半致死浓度和安全浓度，为江苏沿海文蛤大批死亡的原因从侧面提供了分析的依据。  相似文献   

Life cycle of Caligus rogercresseyi, (Copepoda: Caligidae) parasite of Chilean reared salmonids     

Laura Gonzlez  Juan Carvajal 《Aquaculture (Amsterdam, Netherlands)》2003,220(1-4):101-117

Caligus rogercresseyi, [Contrib. Zool. 69 (2000) 137] is the only caligid known to affect the salmon industry in Southern Chile. Economic losses due to reduced fish quality, cost of chemical treatment and outbreaks of other diseases such as the Piscirickettsiosis occur. The life cycle of C. rogercresseyi is described in rainbow trout reared in seawater tanks from observations made under natural conditions of light and temperature between January 1997 and April 1998. Fish were infected with laboratory-cultured larvae obtained from ovigerous females. Rainbow trout were periodically slaughtered for parasite collection and identification. C. rogercresseyi life cycle includes the following stages: two nauplius, one copepodid, four chalimus and the adult. No preadult stage was observed. Timing of the different stages of development was directly dependent on water temperature. The maturation of the eggs or the time for a complete life cycle took place at 45 days in July at 10.3 °C, 31–32 days in April at 12.4 and 12.8 °C, respectively, and at 26 days in November at 15.2 °C. In January, at 16.7 °C, only the appearance of first eggs were observed at 18 days. A simple degree–day (dd) model is proposed for each developmental stage between 4 and 17 °C, where the development rate is a linear function of the average temperature of water. Using this degree–day model, the proportion of fourth stage chalimus was maximum at 172 dd of effective temperature, adult males at 193 degree–days, adult females at 208 dd. The minimum temperature threshold is at 4.2 °C where there is no development of the parasite. The appearance of first eggs occurred at 231 dd and the first pigmented eggs at 277 dd. The temperature-independent degree–days value allowed to predict the timing of C. rogercresseyi life cycle at any temperature within the evaluated range.  相似文献   

不同精子密度冷冻猪5mL细管精液效果比较     

李林林  张德福  马恒东 《畜禽业》2007,(6):20-21

采集上海白猪精液进行5mL细管冷冻,比较冷冻密度分别为0.5×109个/mL、0.7×109个/mL、1.0×109个/mL的冻后精子质量。结果表明:3种密度冷冻猪精子,解冻后精子质量差异不显著(P﹥0.05)。  相似文献   

Substrate concentration affects the in vitro metabolism of 17-hydroxyprogesterone by ovaries of the carp,Cyprinus carpio     

David E. Kime  Mohammad A. S. Abdullah  Miroslawa Sokolowska-Mikolajczyk  Piotr Epler 《Fish physiology and biochemistry》1994,13(4):317-324

Carp ovarian tissue was incubated with ³H-17-hydroxyprogesterone in the presence of 0, 0.1, 1, 10, and 100 μg ml⁻¹ unlabeled 17-hydroxyprogesterone. The pattern of metabolites formed showed a marked variation with substrate concentration. Formation of glucuronide and sulphate conjugates was important only at low substrate concentration. At high substrate concentration (10 and 100 μg ml⁻¹) 17,20α-dihydroxy-4-pregnen-3-one was the major metabolite, but at intermediate concentrations polar 7α-hydroxypregnanetetrols predominated. The results support the hypothesis that at low substrate concentrations conjugating, 5α-reducing and 7α-hydroxylating enzymes, of high activity but low capacity, act as scavengers to deactivate any steroids formed during the relatively low pituitary gonadotrophin secretions which are necessary for oocyte development, but that during the prespawning gonadotrophin surge when high levels of substrate are present these enzymes are saturated and 17,20α-dihydroxy-4-pregnen-3-one (17,20αP) becomes the major ovarian steroid. The possible role of 17,20αP during oocyte final maturation requires further examination.  相似文献   

杂交水稻不同器官重金属铅浓度与累积量   总被引：4，自引：0，他引：4  

陈新红  叶玉秀  潘国庆  赵步洪  杨建昌 《中国水稻科学》2014,28(1):57-64

以生长于盆钵中的两系杂交稻和三系杂交稻共6个组合为试验材料,设置土壤铅(Pb)浓度为500mg/kg和不加Pb土壤(对照)两个处理,测定水稻植株不同器官Pb的浓度和累积量。结果表明,Pb处理降低了两优培九、103S/郑粳2号、丰优香占和汕优63的产量,主要是每穗粒数减少,对其余组合的产量无显著影响;不同基因型水稻植株对Pb吸收与积累存在差异,以103S/郑粳2号和两优培九累积量最多,K优818累积量最少;水稻植株不同器官Pb的浓度和累积量的大小顺序为根>茎鞘>叶片。籽粒不同部位Pb的浓度大小顺序为糠层>颖壳>精米,精米中Pb累积量仅为谷粒的25%左右,精米中Pb的浓度以103S/郑粳2号最高,K优818最低;在抽穗期和成熟期,同一器官Pb浓度与累积量呈显著或极显著正相关,但不同器官之间的相关不显著。对不同杂交稻组合植株中Pb浓度和累积量差异的原因进行了讨论。  相似文献   

氮锌配施对不同玉米品种灌浆期生理特性和籽粒氮锌含量的影响     

张盼盼  邵运辉  刘京宝  乔江方  李川  张美微  黄璐 《核农学报》2022,36(5):1042-1051

提高粮食作物中可食部分的锌生物有效性是解决人体缺锌的重要措施。为研究氮锌肥料施用对玉米籽粒锌营养的影响,本研究以郑单958和谷神玉66为试验材料,在大田条件下研究3个氮水平(90、180 和225 kg N·hm^-2)和2个喷锌处理(0和4.5 kg·hm^-2 ZnSO₄·7H₂O)下玉米籽粒产量和氮锌含量以及灌浆期叶片生理特性的变化。结果表明,吐丝后,与施氮量90 kg·hm^-2处理相比,施氮量180和225 kg·hm^-2处理提高了吐丝后穗位叶SPAD值及硝酸还原酶(NR)、谷氨酰胺合成酶(GS)、碳酸酐酶(CA)、超氧化物歧化酶(SOD)活性和灌浆后期PSⅡ综合性能指数(PI),降低了丙二醛(MDA)含量。施锌能提高吐丝后穗位叶CA、SOD、过氧化物酶(POD)、过氧化氢酶(CAT)活性和灌浆后期SPAD值和PI,降低MDA含量。2个品种相比,谷神玉66灌浆后期穗位叶SPAD值、叶片初始荧光(F_o)和最大荧光(F_m)较高,而灌浆前期穗位叶PI和吐丝后NR、CA、SOD以及POD活性则以郑单958较高。施氮量为90 kg·hm^-2时,玉米籽粒产量平均为8.55 t·hm^-2,随着施氮量增加,玉米籽粒产量显著提高。籽粒中氮含量以施氮量180 kg·hm^-2时最高,为14.85 g·kg^-1。施氮量90和180 kg·hm^-2时,籽粒锌含量平均为27.2 mg·kg^-1,显著高于施氮量225 kg·hm^-2处理。与不施锌相比,喷锌后玉米籽粒产量未有显著变化,籽粒中氮、锌含量分别增加了11.7%和18.0%。郑单958籽粒产量较谷神玉66提高了3.8%,籽粒氮锌含量则分别减少了11.9%和5.3%。综合来看,施氮量为180 kg N·hm^-2时,与喷施ZnSO₄·7H₂O 4.5 kg·hm^-2 配合施用能够增强玉米灌浆期叶片SPAD和荧光特性,提高氮锌代谢关键酶活性,增强氧自由基清除系统酶活性,减弱膜脂过氧化作用的伤害,促进籽粒中氮、锌的吸收和累积。本研究结果可为玉米生产中优化锌生物强化措施提供理论依据。  相似文献