排序方式： 共有51条查询结果，搜索用时 343 毫秒
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Sina Marsilio Shelley J. Newman James Scot Estep Paula R. Giaretta Jonathan A. Lidbury Emma Warry Andi Flory Paul S. Morley Katy Smoot Erin H. Seeley Matthew J. Powell Jan S. Suchodolski Jörg M. Steiner 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2020,34(2):669-677
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选用烟农19、中麦578、伟隆169、华成1688、安农1589、天益科5号、荃麦725、安农0711、西农99、华展199和中育1211共11个适宜皖北地区种植的小麦品种,研究分析了各小麦品种的产量、群体动态变化、干物质转运积累与分配等特性。结果表明,11个供试小麦品种产量均达到7 000 kg·hm-2以上,属高产小麦品种;其中伟隆169、荃麦725、西农99和华展199的产量都达到了8 000 kg·hm-2以上,产量构成协调,穗数及成穗率较高,并且干物质积累量、干物质在籽粒中的分配量以及干物质转运量高于其他品种。相关分析表明,产量与分蘖成穗率呈显著正相关,与穗数呈极显著正相关,伟隆169、荃麦725、西农99和华展199 穗数、分蘖成穗率较高,具有较高产量,适宜皖北地区推广种植。 相似文献
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【目的】 了解并掌握鸭坦布苏病毒(Duck Tembusu virus,DTMUV)流行特点及病毒生物学特性,为DTMUV防治提供理论依据和技术支撑。【方法】 通过细胞及鸡胚接毒试验对河北某鸭场10只具有典型临床症状的发病鸭进行病毒分离,用RT-PCR、透射电镜观察、Western blotting及间接免疫荧光试验(IFA)等方法鉴定,进行动物回归试验测定病毒毒力并对其进行囊膜蛋白遗传进化分析。【结果】 分离到的病毒可在DF-1细胞上稳定增殖产生典型细胞病变效应(CPE)并致死鸡胚;病毒纯化后经电镜观察可见直径30~60 nm的病毒粒子;RT-PCR结果显示,在约270 bp处可见单一条带,与DTMUV预期大小一致;Western blotting结果显示,在60 ku处有特异性条带,与E蛋白大小一致;IFA结果表明,接种病毒的DF-1细胞胞质中可见明亮的特异性荧光,以上结果均表明分离的病毒为DTMUV。将分离到的病毒命名为AX2020株,AX2020株经肌内注射感染北京鸭后感染率高达100%,发病鸭产生神经症状及腹泻等典型临床症状;经序列比对发现AX2020株和GA株(MK907880.1)相似性最高,与SD14毒株(MH748542.1)亲缘关系较远。与商品灭活疫苗毒株HB2010株(MN649262.1)和活疫苗毒株FX2010株(MH414568.1)相比,AX2020株第93、277和487位氨基酸发生了的突变。【结论】 成功分离得到1株DTMUV AX2020株,分离毒株对北京鸭具有较强的致病性,AX2020株的囊膜蛋白与国内疫苗毒株相比,已经发生了氨基酸位点的突变,结果为鸭坦布苏病毒病的流行病学及后续疫苗相关研究奠定了一定的基础。 相似文献
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试验旨在研究骆驼尿液对预防四氯化碳(CCl_4)诱导小鼠肝损伤的保护作用。将40只C57BL/6小鼠随机分为正常组,模型组,骆驼尿液低剂量组(170 mg/kg)、中剂量组(340 mg/kg)和高剂量组(500 mg/kg),3组骆驼尿液组灌胃相应剂量的骆驼尿液,正常组和模型组灌胃等量的生理盐水,每日灌胃1次,连续14 d;试验末期,除正常组外(橄榄油),各组小鼠腹腔注射20%CCl_4橄榄油混合溶液,建立小鼠急性肝损伤模型;12 h后摘眼球取血和采集肝脏样本,并记录肝脏重量,计算肝脏指数;测定小鼠血清相关指标,并进行肝脏组织病理切片检查。结果显示,与模型组比较,低、中、高剂量骆驼尿液组小鼠血清中谷丙转氨酶(ALT)、谷草转氨酶(AST)活性及总胆红素(TBIL)、碱性磷酸酶(ALP)、葡萄糖(GLU)含量较模型组均明显降低,白蛋白(ALB)、总蛋白(TP)含量升高,且高剂量组效果较好;而小鼠肝脏病理学切片观察显示,骆驼尿液组均有不同程度的改善,其中高剂量骆驼尿液组小鼠肝脏组织病理学损伤明显减轻,与正常组的肝脏组织形态接近。比较低、中、高3种浓度骆驼尿液处理发现,浓度越高治疗效果越好,说明骆驼尿液治疗效果具有剂量依赖性。综上所述,骆驼尿液对CCl_4诱导小鼠肝损伤具有一定的预防保护作用,且高剂量骆驼尿液组的效果较好。 相似文献
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Khaki AA Zarrintan S Khaki A Zahedi A 《Pakistan journal of biological sciences: PJBS》2008,11(5):692-701
In the industrial world, almost everyone is unavoidably exposed to ambient electromagnetic field (EMF) generated from various technical and household appliances. Controversy exists about the effects of EMF on various tissues of the living bodies. Seminal vesicles as one of these accessory glands play an important role in natural seminal fluid formation and the effects of EMF on its tissue is worthy of investigation. In order to examine this 30 rat were selected and kept for one weeks in quarantine and 15 (experimental group) were exposed to 50 Hz (non-ionizing radiation) during postnatal life for 2 months. The materials were processed and observed under a light and transmission electron microscope. In the experimental rats epithelial and basal cells showed significant destructions presented by heterochromatin and dense nuclei. Cell debris and abnormal areas was recognizable in the stromal connective tissue. Obvious vacuolization was present within the epithelial cell cytoplasm and also between the cellular organelles. The nuclei of the endothelial cells of the blood vessels were more rigid and endothelial cell cytoplasm contained a lot of vacuoles and pinoctotic vesicles. The results suggested that EMF exposure may cause profound changes in the vesicle seminal tissues. Therefore exposure to EMF may result in pathological changes that lead to sub fertility and infertility. 相似文献
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Sina Adl Vincent Girard Gérard Breton Ardhini Maharning Vincent Perrichot Romain Vullo 《Soil biology & biochemistry》2011,43(4):726-735
Over the past decade, the mid-Cretaceous amber deposits of Charentes (SW France) have been intensively studied. The fossils investigated were not only limited to arthropods preserved in amber, but also included microorganisms, plant debris and vertebrate remains. This plethora of analyses provided important data about the ecology of the overall system, including sources of litter input into the soil and of the above-ground ecology. More precisely, they showed that most of the microfossils were those of soil organisms or organisms that participated in the ecology of the forest soil. This new discovery provided the opportunity to study the ecology of the soil as preserved in the 100 million years old Charentes amber. Indeed, the trophic links of the fossil forest soil have been reconstructed on the basis of the fossil assemblage discovered in amber outcrops and overlayed on a model ecological forest soil food web. We relied on existing phylogenetic information to discuss the absence of certain taxonomic groups in the fossilized specimens. Our synthesis shows that although the organisms of this ancient forest of Charentes were different from those of modern soils, the soil food web was organized functionally the same as modern soils. It also demonstrated that trophic links of the soil community were already diverse, including various means of predation, parasitism and organic matter decomposition. The most obvious differences are the absence of evidence for symbiotic root nitrogen fixation and mycorrhizae. 相似文献
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A Garjani H Rezazadeh S Andalib M Ziaee Y Doustar H Soraya M Garjani A Khorrami M Asadpoor N Maleki-Dizaji 《Iranian Biomedical Journal》2012,16(2):59-67
Background: A growing body of preclinical data indicates that statins may possess antineoplastic properties; however, some studies have raised the possibility that statins may also have carcinogenic potential. Methods: An air pouch model was used for angiogenesis. Single or multiple applications of croton oil on the back of Swiss albino mice with or without initiation by dimethylbenz(a)antheracene (DMBA) were used to evaluate the skin tumorgenesis, ultrastructural and histological alterations. Results: Atorvastatin (orally, 10 mg/kg/day) produced a significant (P<0.05) reduction in angiogenesis. Concurrent administration of mevalonate reversed the anti-angiogenic effect of atorvastatin. However, local injection of atorvastatin (200 µg) into the pouches induced a significant (P<0.5) increase in angiogenesis that was not reversed by co-administration of mevalonate. The disturbance of cell polarity, inflammatory response, thickness of epidermal layer, and mitotic index induced by croton oil were inhibited markedly and dose-dependently (P<0.001) by pre-treatment with atorvastatin. In spite of the strong anti-inflammatory and anti-proliferative effects of atorvastatin on epidermal cell proliferation, it was identified that the same doses of atorvastatin in DMBA-initiated and croton oil-promoted skin tumorgenesis in mice increased the incidence of tumors and their conversion into malignant carcinoma. Conclusion: The reasons for these discrepancies remain unclear, and could be related to ambivalent effects of atorvastatin on angiogenesis or to specific differences in the experimental conditions. It is suggested that the pro-angiogenic effect of the drug, which could be responsible for promotion of skin tumors, is independent of the 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase inhibition that can be mediated directly by atorvastatin.Key Words: Atorvastatin, Angiogenesis, Cell Proliferation, Cancer 相似文献
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Tradable permit schemes (TPS) are market-based policy instruments, which are claimed to be more statically and dynamically efficient in achieving their policy objectives compared to the traditional regulatory instruments. However, some researchers argue that the high level of transaction costs associated with these policy instruments might undermine their efficiency. This paper addresses this issue through exploring the use of Blockchain technology in order to lower transaction costs that arise from TPS transactions. More specifically, it identifies the benefits of using Blockchain smart contracts in implementing TPS that include: increasing the amount of relevant information available to interested actors thus reducing uncertainties; reducing the amount of irrelevant information available to interested actors thus decreasing complexities; correcting information asymmetries among the actors involved thus limiting opportunistic behaviours; lowering the need for the involvement of intermediaries thus decreasing direct monetary costs; and facilitating the linkage between buyers and sellers thus improving trading quality. These potential benefits can increase the efficiency of TPS by decreasing policy-related transaction costs. 相似文献
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