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31.
2021年,山东省临沂市一养殖场养殖的美洲鲥鱼(Alosa sapidissima)突发疾病并出现严重死亡,日死亡率高峰期达到2.5%,累积死亡率约为90%。患病鱼主要症状为体表出血、溃疡,解剖可见腹腔腹水、肝脏暗红,并伴有肠炎。组织病理学检测发现,病鱼肝脏出现弥散性坏死,嗜碱性粒细胞增多和细胞肿胀空泡变性;脾脏出现出血性贫血性坏死灶、核破裂和核固缩;肾脏淋巴细胞坏死脱落,肾小体毛细血管球萎缩,近端小管和远端小管内的细胞出现不同程度的细胞结构消失。发病鱼肉眼和显微镜观察未见明显寄生虫,利用PCR方法检测鲤疱疹病毒2型(Cyprinid herpesvirus 2)、鲈鱼蛙病毒(largemouth bass ranavirus)等淡水鱼类常见病毒均为阴性。细菌分离培养结果显示,从发病鱼的肝脏、肾脏和脾脏中分离得到形态一致的优势菌,命名为AS-AH2101。经16S rRNA测序比对和生理生化鉴定,确定AS-AH2101为嗜水气单胞菌(Aeromonas hydrophila)。毒力基因检测结果显示,AS-AH2101携带气溶素(aerA)、溶血素(hlyA)、丝氨酸蛋白酶(ahpA)、...  相似文献   
32.
This paper studied on the way of Coleus blumei, the leaf was chosen as explants and was inoculated on 1/2 MS medium with different combinations of 6-benzyladenine (6-BA), α-naphthaleneacetic acid (NAA) and indole-3-butyric acid (IBA). The optimal conditions of callus induction from explants were achieved on the medium containing 6-BA (2.0 mg· L^-1) and NAA (1.0 mg· L^-1). Shoot tips were induced on the medium containing 6-BA (4.0 mg·L^-1) and NAA (0.5 mg·L^-1). The same media conditions were found suitable for shoot multiplication, we multiplied shoots rooted best on 1/2 MS medium supplemented with IBA (0.1 mg·L^-1).  相似文献   
33.
通过2个试验研究了饲料中添加蛋白酶AG对鲤鱼生长和前肠蛋白质消化酶活性的影响.试验Ⅰ选用540尾均重11.7 g的鲤鱼,随机均分为6组,随机选取3组分别饲喂鱼粉含量为10%、15%、20%的3种等蛋白基础饲料,另外3组分别饲喂添加有175 mg/kg蛋白酶AG的以上3种饲料,试验期60 d.试验Ⅱ选取120尾均重48.7 g的鲤鱼,随机分为2组,一组饲喂鱼粉含量6%的基础饲料为对照组,另外一组饲喂添加175 mg/kg蛋白酶AG的基础饲料为试验组,试验期为30 d.试验Ⅰ结果表明:摄食10%鱼粉饲料和20%鱼粉 175 mg/kg蛋白酶AG饲料的鲤鱼分别具有最低和最高的增重率;在10%鱼粉饲料中添加蛋白酶AG显著提高了鱼体增重率(P<0.05),但在15%、20%鱼粉饲料中添加蛋白酶AG,对鱼体增重率没有显著影响.试验Ⅱ结果表明:相比于对照组,试验组鲤鱼增重率提高了6.4%(P<0.05),饲料系数降低了5.4%(P<0.05).试验Ⅰ和试验Ⅱ中,添加蛋白酶AG对鱼体肌肉水分、粗脂肪、粗蛋白质含量均无显著影响(P>0.05);对消化酶活性的测定表明,在鱼粉含量为10%、6%的基础饲料中添加蛋白酶AG,可显著提高前肠组织蛋白酶活性和食糜蛋白酶活性(P<0.05),但在鱼粉含量为15%、20%的基础饲料中添加蛋白酶AG,对前肠组织蛋白酶活性和食糜蛋白酶活性没有影响.综上所述,在鱼粉含量较低的饲料中添加蛋白酶AG,可提高鲤鱼消化道蛋白酶活性,改善生长性能.  相似文献   
34.
优质杂交晚稻新组合引种试验初报   总被引:1,自引:0,他引:1  
引进9个晚稻新品种(组合)进行多点比较试验,以两优2163作对照。通过多点试种结果表明:在产量、抗性、米质等综合性状表现比两优2163好的品种为:宜优673、宜优99、Ⅱ优3301、乐优94、两优816。  相似文献   
35.
为了探索绵羊冷冻精液受精率低的原因,在稀释液中用低密度脂蛋白代替卵黄冷冻绵羊精液,研究LDL对冷冻中精子脂类含量的影响。结果表明,以卵黄稀释液冷冻精液,精子胆固醇含量从鲜精的234.54nmol/10^9降低到163.76nmol/10^9精子,胆固醇与磷脂的比值(c/p)从0.54下降到0.36;以9g/100mL LDL代替卵黄,冷冻后胆固醇含量为243.73nmol/10^9精子,c/p值保持在0.50。研究得出在卵黄稀释液中冷冻绵羊精液,精子胆固醇流失,c/p值下降;以LDL代替卵黄,可有效保护精子胆固醇,避免流失,维持了精子c/p值。  相似文献   
36.
杏鲍菇栽培技术研究   总被引:3,自引:0,他引:3  
杏鲍菇 (Pleurotuseryngii)是一种品质优良的大型肉质伞菌 ,子实体单生或群生 ,菌肉厚 ,开伞慢 ,柄组织细密结实 ,雪白粗长 ,孢子少 ,保鲜期长、不同于一般平菇 ,味道鲜美 ,被称为“平菇王” ,寡糖含量丰富 ,口感极佳 ,有整肠美容效果 ,市场前景看好。我所在延  相似文献   
37.
AIM: To demonstrate the susceptibility of cell apoptosis varies during the progress of cell malignant transformation from human being in vitro. METHODS: A SV40T-transfected human bronchial epithelial immortalized cell line (called M) was selected in this work, which has acquired some characteristics of malignant transformation at the later passage. The alterations of apoptosis and bcl-2, P53 genes between early and later passage of M cells were investigated by means of TDT labeling in situ, chromosome FISH, RNA and protein testing, etc. RESULTS: Incidence of apoptosis induced by cis-platin was significantly lower in later than in early passages of M. Levels of bcl-2 mRNA and protein in later passages were higher than early passages of M, and overexpression of bcl-2 was accumulated following the development of cellular malignancy. P53 protein level was as high in early as in later passages. CONCLUSION: Overexpression of bcl-2 decreases the cellular sensitivity to apoptotic inductors plays an important role during progress of carcinogenesis in human bronchial epithelial cancers. The inactivation of P53 protein in the SV40-T transfected M cell line may be one of reasons of bcl-2 overexpression, but not associated with the accumulation of bcl-2 expressed level during cell transformation.  相似文献   
38.
AIM:To investigate the effect of dimethyl sulfoxide on endotoxin -induced fever in rabbits. METHODS:Test substances were administered intravenously into a marginal ear vein. Temperature responses were measured using rectal thermistor probes. RESULTS:Endotoxin (0.4 μg/kg) stimulated a biphasic rise in colonic temperature. Pretreatment with dimethyl sulfoxide significantly attenuated the biphasic febrile response to endotoxin (0.4 μg/kg) of conscious rabbits in a dose-dependent manner. Rabbits treated with dimethyl sulfoxide 10 min after injection of endotoxin developed fever, which was significantly milder compared with rabbits treated with an equal volume of normal saline. No significant differences were found between thermal response index of rabbits injected with dimethyl sulfoxide and those with normal saline. CONCLUSION:Dimethyl sulfoxide inhibit endotoxin-induced fever in rabbits.  相似文献   
39.
AIM To investigate the effects of cytochrome P450 (CYP450) epoxygenase/epoxyeicosatrienoic acid (EET) pathway on insulin resistance in obese mice, and to explore the possible mechanisms. METHODS High-fat diet-induced obesity model was established in C57BL/6Cnc mice, and the obese mice were randomly divided into 3 groups, including obesity group (treated with saline; n=10), EET group (treated with 11,12-EET; n=10) and EET inhibitor 14,15-epoxyeicosa-5(Z)-enoic acid (EEZE) group (n=10). Normal C57BL/6Cnc mice (n=10) treated with saline served as control. Protein expression of CYP2J2 (one of CYP450 epoxygenases) and hypoxia-inducible factor-1α (HIF-1α) was measured by Western blot. Vessel-like structure was detected by immunofluorescence staining. The serum levels of insulin, tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6 and monocyte chemoattractant protein-1 (MCP-1) were measured by ELISA. RESULTS In obese mice, homeostasis model assessment of insulin resistance (HOMA-IR) values were increased, the protein level of CYP2J2 was reduced, and the protein level of HIF-1α was increased in adipose tissues as compared with the controls (P<0.05). The serum levels of MCP-1, IL-1β, IL-6 and TNF-α were also significantly increased in obese mice (P<0.05). After treatment with 11, 12-EET, the HOMA-IR values were decreased compared with vehicle-treated obese mice, HIF-1α expression levels were decreased in the adipose tissue, and the serum levels of MCP-1, IL-1β, IL-6 and TNF-α were reduced (P<0.05). Immunohistochemical results of adipose tissue from vehicle-treated obese mice showed a marked decrease in vessel-like structures (CD31-positive) compared with normal control mice (P<0.05). EET treatment significantly increased the newly formed vessel-like structures in the visceral adipose tissues of obese mice as compared with vehicle-treated obese mice (P<0.05). CONCLUSION High-fat diet-induced obesity and insulin resistance are closely related to the CYP450 pathway. Exogenous EETs effectively decrease obesity-induced insulin resistance possibly through pro-angiogenesis and attenuation of hypoxia and inflammation.  相似文献   
40.
异戊烯基转移酶基因导入番茄及转基因植株再生   总被引:15,自引:0,他引:15  
通过根癌农杆菌(Agrobacteriens)介导,利用特异启动子Psag12与异戊烯基转移酶(Isopenyl transferase,ipt)基因构建的嵌合基因Psag12-ipt对5个番茄品种进行遗传转化,结果共获得来自31个不同外植体的44株转化再生植株。感染子叶的分化再生及转化植株田间生长正常。对其中部分转化再生植株进行PCR检测证明为转基因植株,并且在田间表现出生长旺盛及抗叶片衰老的特性。  相似文献   
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