Retrospective Study: The association of blood lactate concentration with outcome in dogs with idiopathic immune‐mediated hemolytic anemia: 173 cases (2003–2006)

Objective – To determine the association of blood lactate with outcome and response to transfusion therapy in dogs with idiopathic immune‐mediated hemolytic anemia (IMHA). Design – Retrospective study. Setting – Urban veterinary small animal emergency hospital. Animals – One hundred and seventy‐three client‐owned dogs with IMHA. Interventions – None. Measurements and Main Results – Serial blood lactate concentration, therapeutic interventions, and outcome were recorded. Nonsurvivors were defined as those that died or were euthanized. One hundred and thirty‐three dogs (77%) survived, 35 (20%) were euthanized, and 5 (3%) died. One hundred forty‐five dogs (84%; 145/173) had a lactate concentration above the laboratory reference interval [0.46–2.31 mmol/L] on presentation. Blood lactate at presentation was higher in the nonsurvivors (median 4.8 mmol/L; 0.5–13.6) compared with survivors (median 2.9 mmol/L; 0.3–13.2) (P<0.01). All dogs presenting with hyperlactatemia that normalized (<2.0 mmol/L) within 6 hours of admission survived, whereas, 71% of dogs that had a persistent hyperlactatemia at 6 hours survived (P=0.034). Lactate was positively correlated with age, BUN, and alkaline phosphatase, and inversely correlated with PCV. Receiver operating curve analysis for lactate concentration at admission as a test for outcome had an area under the curve of 0.69 with an optimal lactate cutoff concentration of 4.4 mmol/L correctly predicting outcome 73% of the time (sensitivity 60%, specificity 77%). Conclusions – Lactate concentration at presentation was significantly higher in nonsurvivors than survivors. Lactate was significantly correlated with previously reported outcome variables but lactate concentration at admission, as a predictor for outcome was less than optimal. However, serial lactate concentration measurements may be more predictive as patients with persistent hyperlactatemia 6 hours after admission were less likely to survive. Prospective studies evaluating serial lactate concentration while controlling for other variables may provide further insight into lactate measurement as a prognostic indicator in animals with IMHA.     

邻菲萝啉比色法检测羟自由基的研究

Ｆｅｎｔｏｎ反应产生的羟自由基可氧化邻菲萝啉Ｆｅ２＋变为邻菲萝啉Ｆｅ３＋,前者最大吸收峰为５１６ｎｍ,后者５１６ｎｍ处的吸收峰消失。ΔＡ５１６与邻菲萝啉、Ｆｅ２＋及Ｈ２Ｏ２呈量效关系,３７℃保温６０ｍｉｎΔＡ５１６趋于稳定。     

温度和盐度对企鹅珍珠贝清滤率、滤食率、吸收率的影响

采用实验生态学方法研究了温度和盐度对企鹅珍珠贝清滤率、滤食率、吸收率的影响,结果表明,(1) 在盐度28.3～29.1条件下,温度对企鹅珍珠贝的清滤率、滤食率和吸收率产生极显著的影响(P＜0.01);在实验温度(14～32 ℃)范围内,随温度的升高,企鹅珍珠贝的清滤率、滤食率和吸收率增大,29 ℃时均达峰值,分别为0.87 L/h、4.17 mg POM/h和84.01%;温度为32 ℃时,企鹅珍珠贝的清滤率、滤食率和吸收率较29 ℃时均下降,但3个生理指标仍处于较高水平,表明企鹅珍珠贝属典型热带和亚热带品种,表现出对高温的较强适应性;23～32 ℃为企鹅珍珠贝较适宜摄食温度,29 ℃左右为该贝的最佳摄食温度。(2) 在温度27.4～27.8 ℃条件下,盐度对企鹅珍珠贝的清滤率、滤食率和吸收率影响极显著(P＜0.01);在实验盐度(19～37)范围内,随盐度的升高,企鹅珍珠贝的清滤率、滤食率和吸收率增大,盐度为31时均达最大值,分别为0.36 L/h、1.87 mg POM/h和76.95%;盐度为34和37时均下降;盐度为34时,3个摄食生理指标仍呈现较高水平,表明企鹅珍珠贝属典型的狭盐性贝类,表现出对高盐的较强适应性;企鹅珍珠贝较适宜的摄食盐度范围为25～34,最佳摄食盐度为31左右。     

Simulation analysis of piston slap of internal combustion engine

A finite element model of a piston and a block surface was established. After boundary and work conditions were applied, an initial transient analysis of the model was carried out. The simulation result of vibration acceleration on the block surface conformed well with the experiment, thus validating the model. Based on the model, the motion law of pistons in blocks was studied. The variation trend of the piston slap force, piston clearance on the piston slap force, and the effect of piston pin offset on the piston slap force at different crankshaft speeds were analyzed. Results show that suitable piston pin offset and smaller piston clearance reduce the piston slap force quite well; and the contribution of the piston force at the point when gas breaks out is dominant at low speed, which is not obvious at high speed. The findings provide evidence for the performance improvement of internal combustion engine development.      

液压挖掘机工作装置铰点轴和轴套间隙计算模型

分析了挖掘机工作装置铰点轴和轴套配合间隙不合理引发的故障机理。提出了铰点轴和轴套间最小间隙和最大间隙的计算方法,并对计算分析得出的间隙取值与国外同类产品进行了比较。研究结果表明,提出的铰点轴与轴套间隙的计算理论及方法是可行的。     

复方阿莫西林乳房注入剂对临床型奶牛乳房炎的治疗效果

为评价复方阿莫西林乳房注入剂对泌乳期奶牛临床型乳房炎的治疗效果,在甘肃某两个牛场选择70头自然发生的临床型乳房炎奶牛进行临床试验.将患病奶牛随机分为试验组(n=36头)和对照组(n=34头).试验用药和对照用药分别为郑州百瑞动物药业有限公司和齐鲁动物保健品有限公司提供的复方阿莫西林乳房注入剂.每个感染乳区注入3 g药物...     

液环泵叶片轴向叶顶凹槽间隙流场及其性能

为改善液环泵轴向叶顶间隙泄漏流场结构,提升液环泵水力性能,提出液环泵叶片轴向叶顶凹槽结构设计,以2BEA-203型液环泵为研究对象,采用数值模拟方法分析液环泵叶轮轴向间隙泄漏流动及其与主流的相互干扰作用,对比分析凹槽叶顶与平顶间隙泄漏流动及其性能.分析结果表明,液环泵内流动呈现复杂的三维结构,凹槽型叶顶间隙能够在一定范...     

小型可调间隙饲料制粒机设计与试验

为实现小批量颗粒饲料生产,设计一种小型可调间隙饲料制粒机,包括环模及配套部件、压辊及配套部件、传动机构等。该制粒机特征为:压辊调节部件位于制粒机外部,能够在不停机的状态下实时调节模辊间隙,保证颗粒饲料的连续生产。同时设计了与该制粒机配套的控制系统。基于弹塑性理论,采用有限元分析软件Abaqus内置的Drucker-Prager Cap本构模型对制粒机模辊挤压过程进行了数值模拟,模拟结果表明,模辊间隙的设置应与物料的摩擦因数相匹配,适当提高物料的摩擦因数能够避免物料内部滑移耗能,有利于提高颗粒饲料的产量和质量。制造样机并进行了生产试验,以某配方乳猪料为原料,进行制粒机作业性能指标的测定,结果表明:该制粒机生产的颗粒饲料成品含水率为13.53%,直径为3 mm,颗粒含粉率为3.27%,颗粒耐久度(PDI)为94.34%,颗粒硬度为176.03 N,生产率约为42 kg/h,各项指标均达到设计要求,满足小批量颗粒生产的要求。     

变隙式油葵脱粒装置设计与试验

目前已有的油葵脱粒装置无法适用不同条件下的油葵脱粒需求,该文针对油葵在脱粒过程中油葵脱净率较低、籽粒破损率较高等问题,设计了一种基于多杆机构的变隙式油葵脱粒装置。重点介绍了变隙式油葵脱粒装置的结构及工作原理,并对变隙式凹板筛结构的间隙调节机构与角度调节机构进行运动学分析、通过运动轨迹分析和求解,确定了变隙式凹板筛可变间隙为20～60 mm。试制了变隙式油葵脱粒装置试验台,以滚筒转速、脱粒间隙、喂入量作为试验因素,以脱净率、破损率为指标开展正交试验,确定较优作业参数组合。试验结果表明：在脱粒过程中,影响油葵脱净率和籽粒破损率的因素主次顺序为脱粒间隙、滚筒转速、喂入量,较优作业参数组合为脱粒间隙35 mm、滚筒转速280 r/min、喂入量1.8 kg/s。在较优作业参数组合下进行多次重复试验验证,结果表明,油葵的平均脱净率为99.01%,籽粒破损率为2.28%,满足油葵脱粒作业需求。该研究的较优作业参数适用于本文试验的物料条件,实际作业中需调整脱粒凹板筛的直径大小,进而改变脱粒间隙等工作参数以适应不同条件下的油葵脱粒需求。研究结果可为后续油葵脱粒装置的设计提供参考。     

SCINTIGRAPHIC MEASUREMENT OF UTERINE CLEARANCE IN MARES

Uterine clearance of technetium 99m-albumin colloid (^99mTc-μAA) was qualitatively and quantitatively measured in 5 reproductively normal mares and 5 mares susceptible to endometritis (infertile). The percentage of 370 MBq ^99mTc-μAA cleared from the uterine lumen within 2 hr of intrauterine infusion was measured in 10 mares on day 3 of estrus and 48 hr after ovulation. The procedure was repeated 3 times on day 3 of estrus in 6 mares to determine repeatability. Six mares were infused with 1110 MBq ^99mTc-μAA on day 3 of estrus to evaluate the effect of increasing the dose to reduce the imaging time. There was no statistically significant difference in the mean percentage of radiocolloid cleared from the uterus during day 3 of estrus or 48 hr after ovulation or in the percent cleared when the studies were repeated in individual mares. There was no statistically significant difference in uterine clearance between the 370 and 1110 MBq dose studies in each mare from 15 to 120 min. Reproductively normal mares cleared approximately 50% of the radiocolloid from the uterus by 120 min while susceptible mares cleared less than 15%.