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101.
骨骼系统对机体的生命活动至关重要,它为生物体提供了造血微环境、机械支撑、保护脏器等功能,同时也是钙和其他矿物质等的储存库。家鸡尾骨的表型多样性是研究骨骼系统发育及形成机制的良好资源。Notch、Wnt信号通路的靶基因及其相互作用可以形成周期性表达的特点,是调节体节形成及尾部骨骼终止延伸的分子通路。为了解无尾鸡骨骼发育终止的分子机制,作者分别总结了骨骼发育、无尾鸡骨骼研究进展,并重点讨论影响无尾性状的关键信号通路Notch、Wnt及其在无尾鸡研究中的进展。但是,受体和配体之间相互作用的精确调节以及信号通路中的核心元素仍不清楚,需要通过更多的功能基因组和蛋白质组等方法进行深入研究。  相似文献   
102.
The virulence of a strain of hog cholera virus isolated during an outbreak of mild disease in pigs in New South Wales in 1960/61 (the NSW strain) was compared over 11 days with that of a virulent strain by inoculating 8 pigs with each virus and comparing the ensuing clinical signs and pathology. Both viruses caused persistent pyrexia and leukopenia, the NSW strain 4 to 5 days and the virulent strain 3 days, after inoculation. Few other clinical signs were observed in the pigs inoculated with the NSW strain. In contrast, all pigs inoculated with the virulent strain became progressively depressed and incoordinated, and were killed between days 6 and 9. Bronchopneumonia and swollen, reddened lymph nodes were observed in pigs inoculated with both viruses. Few other gross lesions were observed with the NSW strain, but some pigs receiving the virulent strain had pustules in the tonsil and the anterior oesophagus, petechial haemorrhages in the kidney, and small infarcts at the margins of the spleen. There were marked differences in the histopathology, both in the variety of organs affected and the severity of lesions in individual organs. Suppurative bronchopneumonia occurred in both groups. Other changes in the pigs affected with the NSW strain were colitis, mild cerebral vasculitis, necrosis, haemorrhage and neutrophil infiltration in some lymph nodes and spleens. In pigs infected with virulent virus the cerebral vasculitis was so severe that there was necrosis of cells within the vessel walls.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
103.
Quantitative and qualitative differences were demonstrated in the amount of virus in a range of tissues from pigs infected with either the Weybridge or New South Wales (NSW) strains of hog cholera (HC) virus. The titre of the Weybridge strain in samples, as assessed by either virus titration in cell culture or by the density of specific fluorescing cells in tissue sections, was higher than that for the NSW strain. This correlated with the greater severity of the clinico-pathological syndrome induced by the Weybridge strain. The implications of the differences in the virus content of tissues in the diagnosis of HC is discussed as is the use of monoclonal antibodies to differentiate HC and bovine virus diarrhoea viruses.  相似文献   
104.
The motility outcomes of boar semen frozen with newly developed freezing techniques using a new unique freezing technology (UFT) compared with traditional liquid nitrogen methodology were investigated with the intent of improving current fertility outcomes using semen. The UFT is an electronically controlled cooling chamber that houses an organic fluid bath that can be maintained at temperatures below 0 degrees C without solidifying to freeze samples. Four ejaculates from four different boars were collected for this trial. Samples were handled consistently during the pre- and post-freeze processing. From each ejaculate, samples were separated into eight cryopreservation treatment groups, six UFT variations and two control liquid nitrogen groups, immediately before freezing, in replicates of two. After the initial cryopreservation was complete, all samples were stored in liquid nitrogen for at least 48 h. Post-thaw motilities and original motility return percentages were assessed on a random, individual-sample basis. After the initial evaluations, samples from two boars were recollected and frozen using the UFT for breeding purposes. Four sows were bred with the UFT frozen semen to confirm fertility capability. When assessing the individual UFT techniques, all of six UFT techniques had improved post-thaw motilities. However, treatments F (micro = 29%, return micro = 37%) and J (micro = 27%, return micro = 34%) showed the highest statistical improvement for post-thaw (p < 0.05) and original motility percent returns (p < 0.05) when compared with either the control cryo-tube (micro = 15%, return micro = 19%) or straw groups (micro = 12%, return micro = 16%). The UFT semen had a 50% conception rate, with an average of seven piglets from the sows that farrowed. Our preliminary data suggest a higher motility return with a slower pre-freeze phase below the freezing point before the acceleration to liquid nitrogen temperatures. The preliminary data suggest that the UFT could be utilized as a potential cryopreservation option for boar semen.  相似文献   
105.
[目的]为了探索新疆褐牛同期发情处理的有效时间段和最佳处理方法.[方法]采用CUE-MATE孕酮栓+PGF2α法进行新疆褐牛同期发情试验,[结果]表明:同期发情主要集中在取栓后的2 d,平均发情率为72.5%,情期受胎率为66.7%;3月的同期发情率显著高于5月和7月(P<0.05),达到90.8%,但情期受胎率低于5月和7月,为61.0%,差异不显著(P>0.05);母牛卵巢上以有黄体的同期发情率最高,达到95.3%,其次是有卵泡的,无黄体、卵泡的最低,三者差异显著(P<0.05);有卵泡的情期受胎率略高于有黄体的,差异不显著(P>0.05),无黄体、卵泡的同期发情率和受胎率都最低,差异显著(P<0.05);育成牛的同期发情率略高于经产牛,为92%,差异不显著(P>0.05);育成牛的情期受胎率显著高于经产牛(P<0.05),为73.9%.[结论]环境温度、营养水平及母牛卵巢上有无黄体、卵泡影响发情率的高低,CUE-MATE孕酮栓+PGF2α法可用于诱导新疆褐牛的同期发情.  相似文献   
106.
107.
目的ACVR1作为一些TGF-β超家族成员信号通路的I型受体之一,在器官形成和细胞分化及卵泡形成等调控事件中扮演重要角色。迄今,有关ACVR1基因的研究主要集中在人上,有关水牛ACVR1基因的研究尚未见报道。方法采用RT-PCR测序法对槟榔江水牛ACVR1基因的编码区序列进行了分离鉴定,进一步对之进行了功能生物信息学和表达谱分析。结果水牛ACVR1基因编码区全长1 530 bp,编码1个由509个氨基酸残基构成的多肽。水牛ACVR1为弱亲水性蛋白,含有1个信号肽和跨膜区,定位在质膜上;该蛋白含有Activin_recp、TGF_beta_GS和STKc_ACVR1_ALK1三个保守结构域,其二级结构、三维结构与人的ACVR1极为相似。水牛的ACVR1与普通牛、野牦牛、人和猪等8个物种的ACVR1氨基酸序列间一致性Purpose ACVR1, as one of the type I receptors of some members of TGF-β superfamily signaling pathways, plays an important role in the regulatory events such as organ formation, cell differentiation and follicle formation. Up to now, the studies on ACVR1 gene mainly focuses on human, and the research on this gene in water buffalo has not been reported yet.MethodsIn this study, the coding region of ACVR1 gene of Binglangjiang buffalo was isolated and identified by RT-PCR method, and the gene was then subjected to analysis of functional bioinformatics and gene expression profiling.ResultsThe full coding region of buffalo ACVR1 gene is 1 530 bp in length, which encodes a polypeptide consisting of 509 amino acid residues. Buffalo ACVR1 is a weakly hydrophilic protein containing a signal peptide and transmembrane region located on the plasma membrane. Structurally, buffalo ACVR1 contains three conserved domains of Activin_recp, TGF_beta_GS and STKc_ACVR1_ALK1. The secondary structure, three-dimensional structure of this protein are very similar to human ACVR1. The consistency of ACVR1 amino acid sequences between buffalo and 8 other common species such as cattle, wild yak, human and pig was相似文献   
108.
通辽市现有果树总面积1.2429万hm^2,已结果的占55%,以苹果和梨占绝对优势。在树种和品种结构及管理上,都存在一些问题,本文对此进行阐述,提出了改进意见。  相似文献   
109.
The frequency aperture given in this paper is a new method that describes the fracture aperture composition. The aperture curve plays a role in describing the aperture distribution and uniformity. In particular, the frequency hydraulic aperture is of great importance in seepage analysis. It overcomes limitations of hydraulic aperture and mean aperture. Based on existing information, the result of example calculation shows that the hydraulic aperture e h equals to the median aperture e 50 . This paper also obtains that the frequency hydraulic aperture e sh equals to e 48 through finite element numerical modeling for various type of random fracture.  相似文献   
110.
本研究的主要目的是建立鹿血浆盐酸苯嗯唑浓度反相高效液相色谱紫外检测法,探讨盐酸苯噁唑在鹿血浆中的药代动力学.6只临床健康的梅花鹿,同一环境下饲养后肌内注射盐酸苯恶唑(0.44 mg·kg-1),颈静脉采血8 mL后分离血浆,通过建立的高效液相色谱检测法,测定各采血时间的血浆药物浓度.结果表明,盐酸苯噁唑单剂量肌内注射给药后,药代动力学符合吸收一室模型,药代动力学参数吸收半衰期(t1/2Ka)、消除半衰期(t1/2Ke)分别为(2.09±0.34)、(13.18±0.24)min,血浆药时曲线下面积(AUC0→∞)为(70±3.50)(μg·mL-1)·min,最大血药浓度(Cmax)为(4.70±0.50)μg·mL-1,血药达峰时间(Tpeak)为(12.46±0.12)min.试验结果提示,盐酸苯噁唑在鹿体内吸收快,消除迅速,4 h后血浆中无药物残留.  相似文献   
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