人乳腺癌细胞、结肠癌细胞和宫颈癌细胞生长曲线测定

为检测比较人乳腺细胞(MDA-MB-231、MCF-7、HBL-100)、人结肠癌细胞(HCT-8)和人宫颈癌细胞(HeLa)生长曲线的差异性.本实验首先常规培养MDA-MB-231、MCF-7、HBL-100、HCT-8和HeLa细胞,然后应用MTT方法测定这几种细胞的生长曲线.在本实验条件下,这几种细胞生长速度从高...     

陇川县甘蔗产业发展现状及对策

运用SWOT分析法,结合陇川当地实际,对陇川甘蔗产业发展所面临的优势、劣势、机遇及挑战进行深入分析。在此基础上提出相应的对策及建议,旨在提高陇川甘蔗产业经济效益,增加蔗农收入,促进甘蔗产业稳定、高效、健康发展。     

江西鹅鸭地方品种肌肉氨基酸含量的测定与分析

对６个江西地方品种大余麻鸭、吉安红毛鸭、兴国灰鹅、广丰白银鹅、丰城灰鹅和莲花白鹅的胸肌氨基酸含量进行了测定,结果表明：肌肉氨基酸总量和必需氨基酸的含量在６个鹅鸭品种间存在一定的差异。含量最高的是广丰白银鹅。主要的鲜味氨基酸－谷氨酸的含量以吉安红毛鸭最高。而各种氨基酸的相对含量在各品种间基本相似,表明氨基酸的组成具有一定的规律性和相对的稳定性。     

不同营养水平补饲对湘东黑山羊肥育羔羊生产性能的影响

采用80只3~4月龄的湘东黑山羊羔羊,研究3种不同营养水平补饲对肥育羔羊日增重、经济效益的影响。分别在冬、春两个季节进行为期2个月的补饲。试验按完全随机单因子设计,每个季节设4个处理,即3个精料补饲组与1个对照组,每个处理10头湘东黑山羊。参考NRC(1981)的山羊饲养标准设计补充饲料配方,每个季节的3个补饲试验组饲粮的精粗比分别按30∶70、40∶60、50∶50确定,平均补饲量依次按100、200、300g/(d.只)。结果表明冬季补饲试验1、2、3组平均日增重分别为62.75、80.00和85.92g,分别比对照组提高42.06%、81.12%、94.52%,差异显著(P<0.05)或极显著(P<0.01)。春季补饲试验1、2、3组平均日增重分别为85.33、93.50和100.83g,分别比对照组提高38.00%、51.22%、63.08%,差异均为极显著(P<0.01)。从季节对补饲效果来看,冬季的高精料补饲与低精料补饲(精粗比=30∶70)差异显著;春季的精料补饲量对增重影响不大。冬季补饲以精粗料比40∶60为好,春季以30∶70为好。冬季补饲使试验1、2、3组比对照组增加利润分别为5.14、9.23、4.49元/只;春季补饲使试验1、2、3组比对照组增加利润分别为8.97、5.98、2.35元/只。经济效益比较好的补饲量是,冬季187.5g/d,春季154.1g/d。     

鸡骨、肝和肠硷性磷酸酶的提纯和性质

用正丁醇抽提、DEAE纤维素(DE—52)和Con·A—Sepharase 4B柱层析等方法从鸡的骨、肝和肠组织中提取碱性磷酸酶(ALP)。提纯倍数分别为41倍(骨)、391倍(肝)和130倍(肠)。将粗提的ALP进行聚丙烯酰胺梯度凝胶电泳,骨、肝ALP均出现两条带,其分于量为154 000和353 000(骨),187 000和353 000(肝);肠ALP有3个组分,分子量为123 000、235 000和327 000。骨、肝、肠的ATP经DE—52柱层析均得到两个酶峰,其中总活性较大的峰(主峰)进行Con·A—Sepharose 4B柱层析后,其ALP对磷酸苯二钠的km值分别为0.532mM(骨)、0.452mM(肝)和0.472mM(肠)。骨、肝ALP对热敏感,而肠ALP则比较耐热,56℃作用9min,酶活性降低98.8％(骨)、95％(肝)和59.3％(肠)。尿素可抑制骨和肝ALP,肠ALP对尿素不大敏感。4 mol/L尿素对骨ALP活性抑制100％,对肝ALP 95％,对肠ALP仅为47％。2 mmol/L左旋咪唑能抑制骨ALP活性的57.1％、肝ALP的57.7％、肠ALP的15.7％。20 mmol/L L—苯丙氨酸能抑制肝ALP活性的12％、骨ALP的18.5％、肠ALP的57％。低浓度L—苯丙氨酸(1～15mmol/L)对骨ALP几乎没有抑制作用,而对肝ALP有一定抑制作用。上述结果表明,鸡的骨、肝和肠ALP可分为两型:一型为肠ALP,另一型为骨和肝ALP。     

应用A蛋白酶联法快速检测柑桔溃疡病的研究

应用A蛋白酶联法检测柑桔溃疡病表明,A蛋白预包被适宜浓度为2ug/ml,包被抗血清和检测抗血清工作浓度分别为10~(-5)和10~(-3),抗原稀释液和无症样品浸出液的灵敏率分别为1×10~(3-4)cfu/m和1∶90～100倍。此法对省内外26个溃疡病菌株均能检测,而不与阴性抗原发生反应。对171个柑桔无症样品检测表明,阳性率为63.20%,与常规检验结果基本符合。本法不需要纯化抗体及制备酶标抗体,检测周期仅12小时。     

现行制度框架下保障屠宰场猪肉产品质量安全的思考

针对当前生猪定点屠宰中检疫检验分设的制度现状,本文对其设置的历史演变、存在弊端进行了分析,提出了在现行制度框架下利用屠宰场品质检验人员作为指定兽医专业人员实施屠宰检疫操作,优化检疫检验流程,从而化解屠宰检疫检验要求与官方兽医人员不足的矛盾等建议,从而实现保障屠宰场猪肉产品质量安全的目标。     

Conservation status assessment and a new method for establishing conservation priorities for freshwater mussels (Bivalvia: Unionida) in the middle and lower reaches of the Yangtze River drainage

1. The freshwater mussel (Unionida) fauna of the Yangtze River is among the most diverse on Earth. In recent decades, human activities have caused habitat degradation in the river, and previous studies estimated that up to 80% of the mussel species in the Yangtze River are Threatened or Near Threatened with extinction. However, a comprehensive and systematic evaluation of the conservation status of this fauna has yet to be completed.
2. This study evaluated the conservation status of the 69 recognized freshwater mussel species in the middle and lower reaches of the Yangtze River, using the criteria published by the International Union for Conservation of Nature (IUCN). A new method for prioritizing species for conservation was then developed and applied termed Quantitative Assessment of Species for Conservation Prioritization (QASCP), which prioritizes species according to quantifiable data on their distribution and population status, life history, and recovery importance and potential.
3. IUCN assessments showed that 35 (51%) species in the study region are Threatened or Near Threatened (11 Endangered, 20 Vulnerable, 4 Near Threatened). In addition, 16 species (23%) could not be assessed owing to data deficiency. Key threats to the freshwater mussel biodiversity of the Yangtze River include pollution, habitat loss and fragmentation, loss of access to host fish, and overharvesting of mussels and their host fish. The genera Aculamprotula, Gibbosula, Lamprotula, Pseudodon, Ptychorhynchus, and Solenaia were identified as particularly threatened.
4. Data availability allowed QASCP assessment of 44 species. Only Solenaia carinata, regionally Endangered under IUCN criteria, achieved the highest QASCP rank, i.e. First Priority. The five species assessed as Second Priority were considered either regionally Endangered (one), Vulnerable (three), or Data Deficient (one) under IUCN criteria. The 23 Third Priority species were assessed as regionally Endangered (two), Vulnerable (15), Near Threatened (two), or Least Concern (four).

     

SOIL NITROGEN MINERALIZATION UNDER NORTHERN HARDWOOD FORESTS ALONG A SULFATE AND NITRATE DEPOSITION GRADIENT IN THE GREAT LAKES REGION

INTRODUCTIoNChangesinsoilNmineralizationratescouIdbeanearlywarningofsoilNavaila-bilityoreventualforestdeclinesinceNisoftenan.importantnutrientforgrowth(Keeneyl98O;Leaetal.l982;Vitouseketal-l982).Nitrogenmineralizationinvolvestwodistinctprocessesfammonification,inwhichNH:isformedfromorganiccom-pounds,andnitrification,theoxidationofNH:toNO3.ManystudiesofatmosphericdepositionimpactsonforestshavetargetedsoilNmineraIizationusingsimulatedaciddepositionundercontrolledlaboratoryconditions(T…     

农业科研机构科技人员绩效考评指标体系构建研究

科技人员的绩效考评指标体系是否科学合理决定着农业科研机构能否快速发展,构建一套具有农业特征、科学合理、系统全面的绩效考评指标体系是正确评价农业科技人员绩效的前提和基础。文章分析了农业科技人员绩效考评的现状,提出了科技人员绩效考评指标体系的构建思路,并通过探讨中国热带农业科学院科技人员绩效考评指标体系框架,深入分析了定量指标设计,以期为农业科研机构对科技人员进行绩效考评提供现实指导。