首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   193篇
  免费   41篇
林业   15篇
农学   10篇
  45篇
综合类   5篇
农作物   15篇
水产渔业   26篇
畜牧兽医   89篇
园艺   2篇
植物保护   27篇
  2023年   3篇
  2022年   9篇
  2021年   19篇
  2020年   26篇
  2019年   27篇
  2018年   20篇
  2017年   22篇
  2016年   21篇
  2015年   13篇
  2014年   12篇
  2013年   12篇
  2012年   9篇
  2011年   7篇
  2010年   5篇
  2009年   5篇
  2008年   4篇
  2007年   5篇
  2006年   1篇
  2005年   2篇
  2004年   4篇
  2003年   2篇
  2000年   2篇
  1999年   2篇
  1995年   1篇
  1948年   1篇
排序方式: 共有234条查询结果,搜索用时 234 毫秒
71.
A high amount of blood and not the mere presence of blood in equine semen impacts fertility. The aim of this study was to develop an approach to rescue the fertility of stallions with high hemospermia levels. Semen from 15 stallions was divided into four experimental groups: (a) Control—pure raw semen, (b) WB50—50% (v/v) whole blood added into semen, (c) E1—WB50 extended in a 1:1 (v/v) ratio with milk-based extender and (d) E2—WB50 extended in a 2:1 ratio with milk-based extender. Sperm kinetics, plasma membrane integrity (PMI), lipid peroxidation (PER) and intracellular superoxide (O2) production were immediately evaluated. Four cycles of 20 mares were randomly assigned to the experimental groups. Mares were bred with an insemination dose of 1 billion total sperm and pregnancy was diagnosed 14 days after ovulation. Sperm kinetics could not be evaluated in the WB50 samples. Total motility was lower (p < .05) in E1 than in CT and E2 samples. Progressive motility decreased (p < .05) with an increase in the percentage of blood in the samples. The PMI and PER did not differ between groups (p > .05); however, O2 production was higher (p < .05) in WB50 than in E2 samples, while the values were intermediate (p > .05) for CT and E1 samples. The control (90%) and E2 (90%) groups had superior (p < .05) fertility than the others (WB50—0% and E1—25%). It was concluded that sperm motility and fertility of semen with a large amount of blood can be rescued by dilution with a 2:1 extender:semen ratio using a milk-based extender.  相似文献   
72.
73.
The objective of this study was to evaluate and validate the accuracy of the Perkins handheld applanation tonometer for measuring intraocular pressure (IOP) in horses and cattle. Both eyes of 10 adult horses and cattle were evaluated in a postmortem study. The eyes from 10 clinically normal adult horses and cattle were also examined after bilateral auriculopalpebral nerve block and topical anesthesia for an in vivo study. IOP was measured postmortem using direct manometry (measured with an aneroid manometer) and tonometry (measured with a Perkins handheld applanation tonometer). The correlation coefficients (r2) for the data from the postmortem manometry and Perkins tonometer study were 0.866 for horses and 0.864 for cattle. In the in vivo study, IOP in horses was 25.1 ± 2.9 mmHg (range 19.0~30.0 mmHg) as measured by manometry and 23.4 ± 3.2 mmHg (range 18.6~28.4 mmHg) according to tonometry. In cattle, IOP was found to be 19.7 ± 1.2 mmHg (range 18.0~22.0 mmHg) by manometry and 18.8 ± 1.7 mmHg (range 15.9~20.8 mmHg) by tonometry. There was a strong correlation between the IOP values obtained by direct ocular manometry and the tonometer in both horses and cattle. Our results demonstrate that the Perkins handheld tonometer could be an additional tool for accurately measuring IOP in equine and bovine eyes.  相似文献   
74.

Background

Infrared thermography is a painless, noninvasive, nonionizing diagnostic imaging exam used in human medicine as an auxiliary tool for breast cancer diagnosis in women.

Hypothesis/Objectives

Define thermographic mean temperatures of healthy mammary glands and compare these temperatures with those of mammary glands with tumors in dogs.

Animals

Fifty client‐owned female dogs were evaluated, including 20 with histopathologically confirmed mammary tumor and 30 clinically healthy (control).

Methods

A randomized study using infrared thermography analyzed each mammary gland of the animals from the control group and mammary glands with tumors from the tumor group, then the thermographic temperatures obtained were compared. Thermographic exam was performed in a temperature‐controlled room with a cooled thermographic camera—Flir E‐40 (Flir Systems®)

Results

There was significantly a higher temperature in the caudal abdominal and inguinal mammary glands than the other glands in the healthy group (P < .05). Dogs with mammary tumors had significantly higher thermographic temperature compared with unaffected glands regardless of the tumor size and the location (P < .05).

Conclusions and clinical importance

The technique seems to be able to assess for the presence of neoplasia within the mammary tissue in bitches. Further investigation is necessary to determine the impact of this technique when adopted clinically.  相似文献   
75.
The aim of this study was to identify candidate genes and genomic regions associated with ultrasound‐derived measurements of the rib‐eye area (REA), backfat thickness (BFT) and rumpfat thickness (RFT) in Nellore cattle. Data from 640 Nellore steers and young bulls with genotypes for 290 863 single nucleotide polymorphisms (SNPs) were used for genomewide association mapping. Significant SNP associations were explored to find possible candidate genes related to physiological processes. Several of the significant markers detected were mapped onto functional candidate genes including ARFGAP3, CLSTN2 and DPYD for REA; OSBPL3 and SUDS3 for BFT; and RARRES1 and VEPH1 for RFT. The physiological pathway related to lipid metabolism (CLSTN2, OSBPL3, RARRES1 and VEPH1) was identified. The significant markers within previously reported QTLs reinforce the importance of the genomic regions, and the other loci offer candidate genes that have not been related to carcass traits in previous investigations.  相似文献   
76.
The objective of this study was to evaluate the effect of whole raw soybean (WRS) in the finishing diet of Nellore cattle on productive performance, carcass traits, meat quality, fatty acid profile of meat, and blood parameters. In a completely randomized design, 52 Nellore bulls (mean body weight ± SD: 380 ± 34 kg) were allotted for 84 days. The animals received the following diets with a forage: concentrate ratio of 40/60: (i) WRS0: control diet without soybean grains; (ii) WRS8: diet containing 8% WRS in dry matter basis; (iii) WRS16: diet containing 16% WRS, and (iv) WRS24: diet containing 24% WRS. At intervals of 28 days, the animals were weighed, muscle and adipose tissue was analysed by ultrasound, and blood samples were collected. The animals were slaughtered on day 85 and liver weight and hot carcass weight were measured during slaughter. The pH and carcass dressing were calculated at 24 h after slaughter. Longissimus dorsi muscle samples were collected for the determination of fatty acid profile of meat, ether extract, tenderness and sensory analysis of meat aged for 14 days. Blood cholesterol content increased linearly with increasing proportion of whole raw soybean grains. The diet did not affect performance or carcass attributes. The WRS8 had the highest shear force values. In fatty acid profile, C14:0 decreased (p = 0.05), whereas 16:1, 20:0 and 20:1 fatty acids increased linearly with increasing proportion of WRS (p < 0.05). However, concentration of conjugated linoleic acid cis 9, trans 11 and 17:0 increased with WRS24 and WRS16. In the sensory analysis, WRS24 was more tender with respect to the other treatments (p < 0.05). Finally, the inclusion of WRS in the finishing diet of feedlot Nellore bulls only evidenced little changes in fatty acid profile and tenderness, in animals fed diets containing 16 or 24% soybean.  相似文献   
77.
European Journal of Plant Pathology - Multisite fungicides are an anti-resistance strategy to control Phakopsora pachyrhizi. Among the protective fungicides, mancozeb is a fungicide that has been...  相似文献   
78.
Early blight, caused by Alternaria solani and A. grandis, severely affects potato crops around the world, and few management options apart from intensive fungicide use are available. In this work, we tested whether biocontrol treatments with different species of the mycoparasitic fungus Clonostachys could reduce early blight severity on the foliage of pot-grown potatoes of cultivar Ágata, and affect the survival and sporulation of the causal pathogen A. grandis. Twenty isolates from five Clonostachys species were screened in a preliminary biocontrol trial, and nine of them were selected and tested further in two confirmation trials. Treatments with three isolates from three species (C. chloroleuca, C. pseudochroleuca, C. rhizophaga) resulted in a significant reduction in disease severity in both confirmation trials, with control efficacy ranging from 88.7% to 92.9% in the first trial, and from 83.1% to 84.7% in the second trial. All Clonostachys isolates used in the confirmation trials survived on potato leaf tissues for at least 15 days, and resumed growth when subjected to high humidity, resulting in mycoparasitic overgrowth and significant reduction of the pathogen sporulation. Our results provide evidence that different species of Clonostachys, not only the ubiquitous C. rosea, are sources of useful candidates for the biocontrol of potato early blight and possibly other plant diseases caused by fungal pathogens.  相似文献   
79.
European Journal of Plant Pathology - Bauhinia forficata is an important plant commonly used in traditional medicine, and as an ornamental plant in parks and gardens. Its use as an ornamental plant...  相似文献   
80.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号