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71.
利用速生杨木单板,采用高频加热层积弯曲胶合工艺生产弯曲构件,探讨速生杨木代替优质阔叶材生产曲木家具的可行性,并对影响弯曲构件性能指标的因素进行分析。结果表明:速生杨木单板高频加热层积弯曲胶合构件的各项性能指标均超过了企业相关标准,完全可以代替优质阔叶材,用于曲木家具生产。方差及直观分析结果显示, 单板含水率13%,热压压力1.7 MPa,热压时间5 min,保压冷却时间12 min,即可获得满意的弯曲构件性能指标。  相似文献   
72.
为探索适于滴灌的甜菜种植密度及节水灌溉技术,2011年进行了淹灌与滴灌以及滴灌条件不同密度处理对甜菜产量、含糖率及根腐病发病率的影响试验.结果表明,滴灌比淹灌甜菜根腐病发病率低2.3%~2.7%,节水46.9%~64.0%,甜菜整个生育期可节水5567.5m3/hm2,根产量、含糖率都有所提高;滴灌甜菜较适宜密度为8.25~9.75万株/hm2.  相似文献   
73.
电场处理油葵种子对其萌发期水分胁迫敏感性的影响   总被引:3,自引:1,他引:3  
用不同电场强度处理油葵种子15min,以PEG(聚乙二醇)模拟水分胁迫,测定电场处理对种子萌发期抗旱性的影响.结果表明:在0~6.0kV/cm场强范围,不同电场强度,对种子水分胁迫的敏感性的影响程度不同.随着电场强度的增加,种子敏感性以振荡关系变化.适当电场处理条件能够显著地提高种子的吸水率,减轻细胞膜对干旱胁迫的敏感性,从而减小水分胁迫对细胞膜的伤害.提高种子抗旱性最佳电场处理条件的选取与处理时间和电场强度有关.  相似文献   
74.
为探究马传染性贫血病毒(EIAV)附属蛋白Rev负调控Tripartite motif-containing protein 5α(TRIM5α)介导的AP-1信号通路的机制,本研究将pEIAV-Rev-HA和pcDNA3.1质粒分别与含TRIM5α基因的质粒及pGL3-AP-1-Luc(AP-1报告质粒)共转染HEK 293T细胞,采用荧光素酶试验检测Rev对TRIM5α激活的AP-1信号通路的影响;将pEIAV-Rev-HA和pcDNA3.1质粒分别与含TAK1、TAB2、P38和c-Jun基因的质粒及pGL3-AP-1-Luc共转染HEK 293T细胞,采用荧光素酶试验检测Rev对TRIM5α下游转导分子(TAK1、TAB2、P38、c-Jun)激活的AP-1信号通路的影响;将pEIAV-Rev-HA和pcDNA3.1质粒分别与含TAK1、TAB2、P38基因的质粒共转染HEK293T细胞,利用western blot试验分别检测TAK1、TAB2、P38的表达水平;将pEIAV-Rev-HA和pcDNA3.1质粒分别与含P38基因的质粒共转染HEK 293T细胞后加入蛋白酶体抑制剂MG132,利用western blot检测P38蛋白的表达情况。结果显示,共转染EIAV-Rev-HA实验组中TRIM5α对AP-1的激活倍数为0.4,而共转染pcDNA3.1对照组中相应的激活倍数为26.0;共转染pEIAV-Rev-HA实验组中,TAK1、TAB2、P38和c-Jun对AP-1信号通路的激活倍数分别为7.7、0.1、0.6、9.8,而共转染pcDNA3.1对照组中对AP-1信号通路的激活倍数分别为60.0、1.5、6.3、12.0;转染pEIAV-Rev-HA+pP38-Flag组与转染pcDNA3.1+pP38-Flag组相比,前者P38蛋白的表达量显著降低;加入蛋白酶体抑制剂组则恢复了P38蛋白的表达。上述结果表明,EIAV Rev显著下调eqTRIM5α及其下游转导分子TAK1、TAB2、P38激活的AP-1信号通路,但不显著下调c-Jun激活的AP-1信号通路;EIAV Rev通过蛋白酶体途径降解P38蛋白的表达而抑制eqTRIM5α激活的AP-1信号通路。本研究结果为理解EIAV与宿主蛋白相互作用提供参考依据。  相似文献   
75.
以水稻品种空育131为材料,采用小区对比试验方法,研究日式钵育秧盘对寒地水稻植株形态特征和产量形成因子的影响,以探明其对水稻生长和产量的影响。结果表明:水稻应用日式钵育秧盘是通过增加每穴穗数、每穗着粒数和千粒重来提高产量。并在抽穗期,增加了LAI、有效叶面积率和叶片长、宽等指标促进干物质积累。  相似文献   
76.
在水稻生产机械的产业化中,相关的知识产权问题乃是众多法律问题中的基础性问题,而所进行的与水稻生产机械相关的专利权检索则为黑龙江省制定相应的知识产权战略提供了基础性数据,使最终的战略制定更为科学。在对相应检索范围进行框定,检索数据进行筛选、整理与分析的基础上,得出相应的科学结论,并从如何提高黑龙江省专利申请水平、加强各方主体的职能与合作、保护农民权益等角度提出了建议。  相似文献   
77.
近年来寒地水稻旱直播面积有扩大趋势,但生产中存在品种选择随意、保苗率低、杂草防治效果差等现象,导致产量不稳。由于技术还不成熟,盲目扩大规模更容易给农民造成较大损失。针对目前寒地水稻旱直播中存在的问题,初步提出了寒地水稻旱直播栽培技术措施,并探讨了生产中存在的问题与解决方法。  相似文献   
78.
An acute infectious diseases occurred in a koi farm in Fangshan district, Beijing, and it resulted in mortalities of more than 50%.The main symptoms of sick koi were gills necrosis, kidney erosion and edema,which were similar to the clinical signs of koi herpes virus disease (KHVD).But PCR tests showed negative results for KHV. For further diagnosis, bacterial cultures, transmission electron microscopy studies, virus isolation and PCR tests were used. Electron microscopic observation revealed pox virus particles having a size of about 200 nm×400 nm in the kidney. 548 and 180 bp fragments were amplified from organs of sick koi by PCR method using specific primers of carp edema virus (CEV). The fragments were sequenced and analysed. The results showed that they were shared 100% nucleotide identity with CEV-H504. All the results indicated that this disease was carp edema virus disease, caused by a kind of pox virus, CEV. This was the first report on the CEV of cultured koi in China.  相似文献   
79.
AIMS: To determine factors that may influence the efficacy of an oral pelleted vaccine containing Mycobacterium bovis bacille Calmette-Guérin (BCG) to induce protection of brushtail possums against tuberculosis. To determine the duration of protective immunity following oral administration of BCG.

METHODS: In Study 1, a group of possums (n=7) was immunised by feeding 10 pellets containing dead Pasteur BCG, followed 15 weeks later with a single pellet of live Pasteur BCG. At that time, four other groups of possums (n=7 per group) were given a single pellet of live Pasteur BCG orally, a single pellet of live Danish BCG orally, 10 pellets of live Pasteur BCG orally, or a subcutaneous injection of live Pasteur BCG. For the oral pelleted vaccines, BCG was formulated into a lipid matrix, and each pellet contained approximately 107 colony forming units (cfu) of BCG, while the vaccine injected subcutaneously contained 106 cfu of BCG. A sixth, non-vaccinated, group (n=7) served as a control. All possums were challenged by the aerosol route with a low dose of virulent M. bovis 7 weeks after vaccination, and killed 7–8 weeks after challenge. Protection against challenge with M. bovis was assessed from pathological and bacteriological findings.

In Study 2, lipid-formulated live Danish BCG was administered orally to three groups of possums (10–11 per group), and these possums were challenged with virulent M. bovis 8, 29 or 54 weeks later. The possums were killed 7 weeks after challenge, to assess protection in comparison to a non-vaccinated group.

RESULTS: The results from Study 1 showed that vaccine efficacy was not adversely affected by feeding dead BCG prior to live BCG. Feeding 10 vaccine pellets induced a level of protection similar to feeding a single pellet. Protection was similar when feeding possums a single pellet containing the Pasteur or Danish strains of BCG. All vaccinated groups had significantly reduced pathological changes or bacterial counts when compared to the non-vaccinated group. In Study 2, oral administration of Danish BCG induced protection against challenge with M. bovis, which persisted for at least 54 weeks after vaccination. Some protection was observed in possums challenged 54 weeks after vaccination, but this protection was significantly less than that observed in groups vaccinated 29 or 8 weeks prior to challenge. There was a strong relationship between the proportion of animals producing positive lymphocyte proliferation responses to M. bovis antigens and protection against challenge with M. bovis.

CONCLUSIONS: Factors considered potentially capable of interfering with vaccination, including feeding dead BCG to possums prior to feeding live BCG, feeding multiple doses of BCG at one time, and changing strains of BCG, were shown not to interfere with the acquisition of protective immune responses in possums. Protection against tuberculosis was undiminished up to 29 weeks after vaccination with BCG administered orally. It is concluded that vaccination of possums by feeding pellets containing BCG is a robust and efficient approach to enhance the resistance of these animals to tuberculosis.  相似文献   
80.
Because of the importance of reproduction in stock breeding systems, it is necessary to find selection criteria that increase reproductive efficiency. The aim of this study was to estimate genetic parameters for the probability of conception on first service (PROB) in Murrah heifers, and its association with other traits of economic interest [age at first calving (AFC), service period, calving interval and milk yield at 270 days], with the purpose of evaluating their use as selection criteria. Reproductive information and first lactation records of 1200 Murrah heifers were used to perform two‐trait analyses between PROB and the other characteristics. Bayesian inference was used to estimate the variance components, considering PROB as threshold and the other as linear factors. The results demonstrate that this trait has heritability of 0.15, indicating the possibility of a genetic gain by using it for selection. With respect to the genetic correlation estimates, the only high‐magnitude association was with AFC (?0.899), which is the current criterion indicating sexual precocity of females. In the light of the parameters estimated, the first‐service pregnancy rate is an alternative for indication of sexual precocity, although presenting a smaller genetic gain than the current standard AFC. Nevertheless, additional research should be conducted regarding this trait to assess the economic importance of its use in dairy buffalo production systems.  相似文献   
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