Echocardiographic Estimates of Right Ventricular Systolic Function in Dogs with Myxomatous Mitral Valve Disease          下载免费PDF全文

E.H. Chapel  B.A. Scansen  K.E. Schober  J.D. Bonagura 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2018,32(1):64-71

Background

Right ventricular (RV) dysfunction independently predicts outcomes in human myxomatous mitral valve disease (MMVD). There is limited information regarding RV systolic function in dogs with MMVD.

Hypothesis

Right ventricular systolic function differs among stages of disease, decreasing in decompensated MMVD.

Animals

Thirty‐sixclient‐owned dogs with MMVD not receiving oral cardiovascular medications.

Methods

Prospective clinical study. Dogs were categorized according to disease severity as ACVIM Stage B1, B2, or C. Seven echocardiographic indices of RV systolic function were measured. Groups were compared by 1‐way ANOVA and Tukey's HSD test. Frequencies of cases with cardiac remodeling falling outside previously established reference intervals were compared using Fisher's exact test. Intra‐ and interobserver measurement variability was calculated for each RV function index.

Results

The indices TAPSE (P = 0.029), RV St_L (P = 0.012), and RV StR_L (P = 0.041) were significantly different between groups. A greater proportion of B2 dogs (7 of 12) had TAPSE values above reference intervals compared with B1 (2 of 12) or C (2 of 12) dogs (P = 0.027). Measurement variability of TAPSE, RV S', and RV St_G was clinically acceptable.

Conclusions and Clinical Importance

Right ventricular systolic function differs between stages of MMVD, increasing in stage B2, and declining in stage C. The prognostic importance of RV function indices, particularly TAPSE, might be worth evaluating in dogs with MMVD.  相似文献   

四个紫花苜蓿品种种子萌发期耐盐性研究     

李松阳  王晓丽  马玉寿  王彦龙  年勇  李林栖  景美玲 《青海畜牧兽医杂志》2018,(1):7-11,17

在实验室内模拟的盐分条件下,用不同浓度的Na Cl盐溶液对4个紫花苜蓿品种(中苜1号、中苜3号、中草3号和陇东苜蓿)种子萌发期进行盐胁迫处理。结果表明:低浓度(0.2%和0.4%)的盐溶液对苜蓿的发芽率和幼苗苗高抑制作用不显著,对幼根具有一定的刺激作用。0.8%和1.0%的Na Cl溶液处理下发芽率、0.6%的Na Cl溶液处理下的幼苗苗高和幼根生长量可以作为苜蓿种子萌发期耐盐性鉴定指标。对四个紫花苜蓿品种的发芽率、幼苗苗高、幼根生长量、耐盐半致死浓度四个指标进行综合分析,结果表明:中苜1号耐盐性最强,其次是中苜3号和中草3号,陇东苜蓿最弱。  相似文献   

Differential gene expression of Eph‐ephrin A1 and LEPR‐LEP with high or low number of embryos in pigs during implantation          下载免费PDF全文

Y Fu  S Ren 《Reproduction in domestic animals》2018,53(4):937-946

The objective of this study was to ascertain whether mRNA and protein expressions of implantation‐related genes (erythropoietin‐producing hepatocellular receptor–ligand A1, Eph‐ephrin A1 and leptin receptor–leptin, LEPR‐LEP) differed between pigs with high and low number of embryos, and whether these differences in gene expression might affect embryo implantation. Experimental pig groups (n = 24) for high and low number of embryos were prepared by altering the number of eggs ovulated in pre‐pubertal gilts treated with 1.5 × (High) or 1.0 × (Low) PG600 ([400 IU PMSG + 200 IU hCG]/dose, AKZO‐NOBEL). Gilts expressing oestrus were artificially inseminated twice and maintained in breeding and gestation until the reproductive tract was collected on day 22 of pregnancy. At slaughter, the reproductive tracts from each pregnant gilt from each treatment were immediately processed to collect samples for RNA and protein analysis. Within each gilt, three conceptus points were sampled, one from each horn and then a random conceptus within the tract. At each conceptus point, endometrial attachment site, chorion–allantois and embryo were collected and immediately frozen in liquid nitrogen. Number of corpus luteum (CL) (35.4 vs. 12.6) and total embryo number (18.8 vs. 10.2) were greater in the high‐embryo compared to the low‐embryo group, respectively (p < .05). Real‐time qPCR results showed that Eph‐ephrin A1 mRNA expression was less in the high‐embryo (p < .05) compared to the low‐embryo group. In addition, Western blotting analysis indicated that Eph‐ephrin A1 and LEP protein expression at endometrial attachment site in high‐embryo was less (p < .05) compared to low‐embryo group. It was also noted that mRNA expression of Eph‐ephrin A1 and LEPR‐LEP was greater in pregnant than non‐pregnant gilts (p < .05). Moreover, mRNA expression of Eph‐ephrin A1 (p < .05) and LEPR‐LEP was greatest at endometrial attachment site among all three tissues. There was a positive correlation between expressions of Eph‐ephrin A1, LEPR‐LEP and embryo length with the correlation coefficient 0.31–0.59. For Eph‐ephrin A1, the highest correlation coefficient appeared between Eph A1 expression and normal embryo number, between ephrin A1 expression and embryo length. For LEPR‐LEP, the highest correlation coefficient appeared between LEPR‐LEP expression and ovary weight (0.79 for both, p < .05), followed by embryo length and weight. The results of this study suggest that low expression of Eph‐ephrin A1 and LEPR‐LEP is somehow related to increased embryo number during implantation and that endometrial attachment site might be the main target tissue of these gene products. Yet, the increased expression of Eph‐ephrin A1 and LEPR‐LEP appeared associated with increased embryo growth (length and weight) and ovary weight, Eph‐ephrin A1 and LEPR‐LEP might play roles in the regulation of embryo implantation in pigs.  相似文献   

Ecological consequences of variation in standard metabolism and dominance among salmon parr     

John D. Armstrong  Karen J. Millidine  Neil B. Metcalfe 《Ecology of Freshwater Fish》2011,20(3):371-376

Abstract – Standard metabolic rate (SMR, closely related to basal and resting metabolism) varies by up to threefold among juvenile Atlantic salmon, Salmo salar L., of similar size at common temperature. Here, consequences of this variation are predicted by combining empirically derived relationships between SMR, specific dynamic action, energy budgets, water velocity, food level in the environment and food availability to fish. The range of velocities across which growth is predicted to occur is inversely related to a fish’s SMR. Growth is positively related to SMR at high but negatively related to it at low‐food levels. The relationship between food level and the range of velocities over which lower SMR fish can grow but higher SMR fish cannot is asymmetrically bi‐phasic and peaked. It is predicted that maternal manipulation of offspring SMR would generate fitness benefits through bet‐hedging against unpredictability in food level and increases in the overall range of velocities that the family of offspring can occupy and thrive in.  相似文献   

粉条加工中添加石蜡的检测技术研究     

袁秀金  赵天珍 《广西农业科学》2011,(8):972-974

【目的】探讨粉条加工过程中非法添加石蜡的测定方法,为食品监管提供保障。【方法】先以石蜡成品摸索石蜡测定的气相色谱质谱条件,再以石蜡成分C18H38和C24H50进行回收率和相对标准偏差试验。【结果】不同预处理方法中,超声萃取处理的C18H38和C24H50在粉条中的萃取回收率最高,分别为93.5%和91.0%;20min超声时间萃取粉条中烷烃成分较为适宜;所建立的粉条中石蜡含量测定方法的相对标准偏差为3.6～4.8,样品回收率均大于90.0%,达到定量检测要求。【结论】所建立的石蜡检测方法操作简单,测定结果准确可靠,可用于粉条中石蜡成分的定性及定量测定。  相似文献   

辽西北困难立地造林有关建议     

刘晓艳 《北京农业》2011,(30):132

辽西北地区造林成效很低究其根源,概括起来,困难立地造林主要问题也不少。  相似文献   

速生林木材液化及其产物应用研究     

巫国富  许忠允  潘晖 《安徽农业科学》2011,39(5):2776-2777

[目的]为速生桉树木材液化及其产物的应用提供参考。[方法]以硫酸为催化剂,苯酚为液化剂,对速生人工林桉树木材进行液化,并取液化产物与甲醛进行树脂化反应制备液化木基酚醛树脂LWPF,研究液比对液化反应效率、液化产物重均分子量及LWPF树脂胶合性能的影响。[结果]随着液比的提高,液化产物的残渣率及重均分子量均降低,而LWPF树脂制得的胶合板的木破率提高;当液比提高到一定程度后,液化产物的残渣率和重均分子量及LWPF树脂所制胶合板的木破率变化不明显。[结论]对速生桉树木材的液化工艺及其液化产物的树脂化合成工艺进行了优化。  相似文献   

提取剂对大蒜鳞茎提取液抑制黄瓜枯萎病的效应     

郑成锐  林辰壹 《中国园艺文摘》2011,27(1):26-27

为反映提取剂类型对大蒜鳞茎提取液抑菌能力的影响,用水、乙醇,丙三醇作为大蒜鳞茎杀菌物质的提取剂,采用孢子萌发法对黄瓜镰刀菌枯萎病菌孢子抑杀.研究结果表明,3种提取溶剂制成的大蒜鳞茎提取液对枯萎病菌孢子抑制的EC50值分别为0.2884%、0.2818%和0.2454%,较低的提取液浓度达到了较好的抑菌效果.水、乙醇、丙三醇都可以作为大蒜鳞茎的提取剂,3种提取溶剂的大蒜鳞茎提取液毒力相当,孢子抑制萌发率随着大蒜鳞茎提取液浓度增加而升高.  相似文献   

支管射流三通结构优化与试验     

薛子龙  王新坤  樊二东  徐胜荣  王轩  张晨曦 《排灌机械工程学报》2020,38(7):751-756

为了提高支管射流三通水力性能,改善滴灌的灌水均匀性,基于CFX数值模拟技术,对进口宽度为15 mm的支管射流三通进行结构优化.选取位差、劈距、劈尖半径和侧壁倾角为影响因素,通过四因素三水平正交设计了9组模型,边界条件设定为进口压力100 kPa.选取支管射流三通出口设计流量为评价标准,支管射流三通最优结构尺寸为位差5.5 mm、劈距113 mm、劈尖半径13 mm、侧壁倾角10°.此结构尺寸参数下的支管射流三通水力性能试验结果表明:在进口水压为100 kPa时,支管射流三通脉冲频率为148次/min,水头压力振幅为37.9 kPa,水头压力损失为16.7 kPa,出口流量为0.698 L/s;支管射流三通所接滴灌带长度为60 m时,与普通支管三通相比,支管射流三通的灌水均匀系数提高了2.78%,流量偏差率降低了4.72%.该研究可为射流技术在脉冲滴灌系统的研究、开发与应用提供理论依据.  相似文献   

浅谈林业生产中的造林及抚育技术     

王国辉 《内蒙古林业科技》2020,46(1):63-64

在林业生产的过程中,采用正确、合理的造林技术和抚育技术,能够提高造林成活率,确保林木健康生长,并在短时间内构建完善的林分结构。而科学的抚育管理,又能进一步挖掘林业发展潜力,提升林地质量和产量,为林业发展创造更多的空间。同时做好造林和森林抚育工作,能够有效地促进林业科学发展,更好地应对全球气候变化的挑战。  相似文献