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排序方式: 共有276条查询结果,搜索用时 15 毫秒
161.
运用层次分析法和模糊数学综合评判方法,根据石河子、昌吉、吐鲁番等8个地区的无霜期、温度、积温和降水因素,建立了数学模型,并对新疆天然甜型葡萄酒原料种植区域进行了区划研究.结果表明:吐鲁番的综合评价最高,其次为和田,评价值分别为0.97和0.91,属非常适宜种植区;哈密和喀什的评价值分别为0.81和0.87,属适宜种植区;库尔勒的为0.71,属次适宜种植区,而石河子、昌吉和霍城的评价值均小于0.59,属不适宜种植区. 相似文献
162.
采用自由基聚合法,以过硫酸钾为引发剂,磷酸酯淀粉与丙烯酸钠和丙烯酸钾进行接枝共聚,合成了含磷、钾的高吸水树脂;磷酸酯淀粉与低中和度的丙烯酸接枝共聚合成的高吸水树脂用氨水浸泡,自然凉干得到含氮、磷、钾的高吸水树脂,详细考察了丙烯酸的中和度对吸水保水剂吸液性能的影响。通过实验得到了合成该吸水保水剂的适宜条件。 相似文献
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164.
Clements DN Vaughan-Thomas A Peansukmanee S Carter SD Innes JF Ollier WE Clegg PD 《American journal of veterinary research》2006,67(8):1438-1444
OBJECTIVE: To assess 2 methods of RNA purification by use of different quality metrics and identify the most useful metric for quality assessment of RNA extracted from articular cartilage from dogs with osteoarthritis. SAMPLE POPULATION: 40 articular cartilage specimens from the femoral heads of 3 clinically normal dogs and 37 dogs with osteoarthritis. PROCEDURES: RNA was extracted from articular cartilage by 2 purification methods. Quality metrics of each sample were determined and recorded by use of a UV spectrophotometer (Spec I; to determine the 260 to 280 nm absorbance ratio [A(260):A(280) ratio]), a second UV spectrophotometer (Spec II; to determine A(260):A(280) and A(260):A(230) absorbance ratios), and a microfluidic capillary electrophoresis analyzer (to determine the ribosomal peak ratio [RR], degradation factor [DF], and RNA integrity number [RIN]). The RNA was extracted from affected (osteoarthritic) articular cartilage and assessed with the same quality metrics. Metric results were compared with visual analysis of the electropherogram to determine the most useful RNA quality metric. RESULTS: No differences in methods of RNA purification were determined by use of quality metrics. The RNA extracted from unaffected (normal) cartilage was of higher quality than that extracted from affected (osteoarthritic) cartilage, as determined by the RIN and Spec II A(260):A(230) ratio. The RIN and RR were the most sensitive metrics for determining RNA quality, whereas the DF was most specific. A significant proportion (32%) of RNA extracted from osteoarthritic articular cartilage specimens was determined as being of low quality. CONCLUSIONS AND CLINICAL RELEVANCE: No single metric provided a completely sensitive and specific assessment of the quality of RNA recovered from articular cartilage. 相似文献
165.
Barrett DJ Clegg T Healy AM Doherty ML 《Journal of veterinary medicine. A, Physiology, pathology, clinical medicine》2006,53(3):140-144
Somatic cell count (SCC) data for 480 cows in 10 Irish dairy herds from January 2001 until June 2002 were analysed. Herds were selected on the basis of a recent or ongoing history of clinical or subclinical mastitis. An individual cow SCC of 200 000 cells per ml was used as the threshold for elevation of SCC. The duration of elevated SCC prior to drying-off and the magnitude of the elevation in SCC were found to have an impact on the response to dry cow therapy (DCT). A trend also emerged indicating that increasing parity had a negative influence on the response to DCT. 相似文献
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168.
Vandeweerd JM Vandeweerd S Gustin C Keesemaecker G Cambier C Clegg P Saegerman C Reda A Perrenoud P Gustin P 《Journal of veterinary medical education》2012,39(2):142-151
Understanding how veterinary practitioners make clinical decisions, and how they use scientific information to inform their decisions, is important to optimize animal care, client satisfaction, and veterinary education. We aimed to develop an understanding of private practitioners' process of decision making. On the basis of a grounded-theory qualitative approach, we conducted a telephone survey and semi-structured face-to-face interviews. We identified a decision-making framework consisting of two possible processes to make decisions, five steps in the management of a clinical case, and three influencing factors. To inform their decision, veterinary surgeons rarely take the evidence-based medicine (EBM) approach. They consult first-opinion colleagues, specialists, laboratories, and the Internet rather than scientific databases and peer-reviewed literature, mainly because of limited time. Most interviewees suggested the development of educational interventions to better develop decision-making skills in veterinary schools. Adequate information and EBM tools are needed to optimize the time spent in query and assessment of scientific information, and practitioners need to be trained in their use. 相似文献
169.
应用ANSYS有限元软件对寒冷干旱的呼和浩特地区常用的节能型日光温室结构进行了三维分析,研究了日光温室在作物载荷与雪载,南风载荷和北风载荷三种不利载荷组合情况下的受力,然后对日光温室的前、后屋面角、弦杆弧度和结构杆件的截面尺寸进行了优化设计.优化后的温室结构与优化前相比可节省用钢量约1.43kg/m2;温室的全部结构杆件均采用标准钢材确定,利于采购和日光温室的建造;前、后屋面角经优化后对温室内部采光也较有利. 相似文献
170.
ABSTRACT: By international standards, Ireland is a relatively small dairy producer. However, the industry plays a critical role to the national economy, accounting for approximately 3% of national gross domestic product. This paper presents insights into udder health and intramammary antibiotic usage on Irish dairy farms during 2003-2010, based on data from several sources. Three data sources were used, including data on milk recording data, intramammary antibiotic sales and animal health assessment. The milk recording data included a single unadjusted herd-level somatic cell count (SCC) value for each herd at each milk recording, being the arithmetic mean of cow-level SCC of each cow at that recording, weighted by cow-level yield. These data were used to calculate the percentage of herds each month where the unadjusted herd SCC exceeded 200,000 and 400,000 cells/mL. Two logistic generalised estimating-equations (GEE) models were developed, the outcome variable being either the probability that the monthly SCC of a herd was greater than 400,000 cells/mL or less than or equal to 200,000 cells/mL. Spring herds had a lower probability of a high SCC (> 400,000 cells/mL) during February to October compared to non-Spring herds but a higher probability between November to January. The odds of a high SCC were greater in 2005, 2006, 2009 and 2010 but less in 2007 and 2008 compared to 2004. Smaller herds had higher odds of having a high SCC compared to larger herds. We present the number of intramammary tubes and the quantity of active substance (kg) sold annually in Ireland during 2003-2010. We infer an incidence of clinical mastitis of 54.0 cases per 100 cow-years at risk, assuming 4 tubes per treatment regime, one affected quarter per cow, tubes restricted to clinical cases only and 100% of treated cases considered new cases, based on data collected on sales of in-lactation intra-mammary antibiotics. With differing assumptions, this estimate varied between 25.8 and 77.0 cases per 100 cow-years at risk. Using data on sales of dry cow therapy intra-mammary antibiotics, we also infer that most Irish dairy farmers use blanket dry cow therapy. It is important that Ireland has an objective understanding of current levels of udder health, to facilitate benchmarking and improvement into the future. Udder health is a concern on a number of Irish dairy farms. High SCC results were present throughout the year, but more marked towards the start and end of each milking season. Animal Health Ireland recently commenced a major national programme, CellCheck, in collaboration with a broad range of stakeholders, to support national SCC improvement. In this paper, relevant European and national legislation is also reviewed. 相似文献