全文获取类型
收费全文 | 322篇 |
免费 | 23篇 |
国内免费 | 1篇 |
专业分类
林业 | 2篇 |
基础科学 | 1篇 |
11篇 | |
综合类 | 31篇 |
农作物 | 7篇 |
水产渔业 | 3篇 |
畜牧兽医 | 282篇 |
植物保护 | 9篇 |
出版年
2023年 | 2篇 |
2022年 | 2篇 |
2020年 | 6篇 |
2019年 | 5篇 |
2018年 | 8篇 |
2017年 | 9篇 |
2016年 | 8篇 |
2015年 | 6篇 |
2014年 | 9篇 |
2013年 | 25篇 |
2012年 | 4篇 |
2011年 | 9篇 |
2010年 | 3篇 |
2009年 | 19篇 |
2008年 | 7篇 |
2007年 | 17篇 |
2006年 | 18篇 |
2005年 | 15篇 |
2004年 | 18篇 |
2003年 | 19篇 |
2002年 | 6篇 |
2001年 | 9篇 |
2000年 | 6篇 |
1999年 | 9篇 |
1998年 | 8篇 |
1997年 | 10篇 |
1996年 | 5篇 |
1995年 | 4篇 |
1993年 | 5篇 |
1992年 | 6篇 |
1991年 | 7篇 |
1990年 | 6篇 |
1989年 | 8篇 |
1988年 | 7篇 |
1987年 | 3篇 |
1986年 | 6篇 |
1983年 | 4篇 |
1980年 | 2篇 |
1976年 | 1篇 |
1975年 | 2篇 |
1971年 | 2篇 |
1970年 | 1篇 |
1969年 | 2篇 |
1968年 | 1篇 |
1967年 | 2篇 |
1945年 | 1篇 |
1944年 | 3篇 |
1942年 | 1篇 |
1926年 | 1篇 |
1925年 | 2篇 |
排序方式: 共有346条查询结果,搜索用时 323 毫秒
1.
Three in vitro assays to detect benzimidazole resistance, namely, the egg-hatch assay, tubulin-binding assay, and a larval-development assay, were evaluated by estimating the level of benzimidazole resistance in three field isolates of Haemonchus contortus compared with a susceptible reference strain. Comparisons were also made with estimates of benzimidazole resistance of the three field strains obtained from an in vivo controlled anthelmintic efficacy test. All three in vitro tests showed similar, consistent results which also suggested greater sensitivity than the in vivo assay. These results indicate that selection of an in vitro technique to determine benzimidazole resistance should therefore be based on considerations other than precision, such as technical expertise, availability of equipment, cost and speed in which diagnosis is required. 相似文献
2.
3.
4.
Waller PJ 《New Zealand veterinary journal》1992,40(1):1-3
Control of nematode parasites in ruminants is directed almost exclusively at the parasitic stage in the host using conventional anthelmintic therapy. However, to complete their life cycle, parasites have to develop through a series of free-living stages on pasture. It is within this environment that there is a vast range of cohabiting micro-organisms, some of which are known to infect or prey on nematodes. These include bacteria, protozoa, viruses and fungi. To date, most interest has been focused on those organisms producing chemical toxins which have been developed as anthelmintics, e.g. Streptomyces/avermectins. Yet the potential of predacious and nematoxic fungi and bacteria for the biological control of nematode parasites of livestock remains largely untapped. These organisms may well offer a cheaper and more sustainable approach to reducing the impact of parasitism in livestock. 相似文献
5.
JC Ousey 《Reproduction in domestic animals》2004,39(4):222-231
The endocrine profiles in the periparturient mares are dominated by increasing concentrations of progestagens and decreasing oestrogens. These hormones are produced by precursors from the foetus, metabolized by the placenta and act primarily on the maternal uterus. The circulating concentrations of hormones in maternal plasma, generally, represent a small proportion of those metabolized by the foetus and utero-placental tissues. There is clear evidence that the foetal hypothalamo-pituitary-adrenal (HPA) axis initiates the process of foetal maturation and the hormonal cascade which culminates in parturition at term. The endocrine changes associated with abnormal pregnancy and abortion in late pregnancy are less well understood, as are the hormonal treatments needed to avert these problems. Further work is needed to establish the biological role of the various hormones present in pregnant mares and, in particular, those hormones which control myometrial quiescence. 相似文献
6.
7.
RJ Barnewall IB Marsh PMV Cusack F Galea N Sales JC Quinn 《Australian veterinary journal》2023,101(6):254-257
Bovine respiratory disease (BRD) exerts a major impact on the beef cattle industry nationally and worldwide, with a range of aetiological factors impacting its pathogenesis. Previous research has focussed on an increasing number of bacteria and viruses that have been shown to play a role in eliciting disease. Recently, additional agents have been emerging as potential contributors to BRD, including the opportunistic pathogen Ureaplasma diversum. To determine if U. diversum was present in Australian feedlot cattle and if that presence was linked to BRD, nasal swabs were collected from a cohort of 34 hospital pen animals and compared to 216 apparently healthy animals sampled contemporaneously at feedlot induction and again after 14 days on feed at an Australian feedlot. All samples were subjected to a de novo polymerase chain reaction (PCR) assay targeting U. diversum in combination with other BRD agents. U. diversum was detected at a low prevalence in cattle at induction (Day 0: 6.9%, Day 14: 9.7%), but in a significantly greater proportion of cattle sampled from the hospital pen (58.8%). When considering the presence of other BRD-associated agents, co-detection of U. diversum and Mycoplasma bovis was most common in hospital pen animals receiving treatment for BRD. These findings suggest that U. diversum may be an opportunistic pathogen involved in the aetiology of BRD in Australian feedlot cattle, in combination with other agents, with further studies are warranted to identify if a causal relationship exists. 相似文献
8.
Profile of Steroid Receptors and Increased Aromatase Immunoexpression in Canine Inflammatory Mammary Cancer as a Potential Therapeutic Target 下载免费PDF全文
PJ De Andrés S Cáceres M Clemente MD Pérez‐Alenza JC Illera L Peña 《Reproduction in domestic animals》2016,51(2):269-275
Canine inflammatory mammary cancer (IMC) has been proposed as a model for the study of human inflammatory breast cancer (IBC). The aims of this study were to compare the immunohistochemical expression of aromatase (Arom) and several hormone receptors [estrogen receptor α (ERα), estrogen receptor β (ERβ), progesterone receptor (PR) and androgen receptor (AR)], in 21 IMC cases vs 19 non‐IMC; and to study the possible effect of letrozole on canine IMC and human inflammatory breast cancer (IBC) in vitro using IPC‐366 and SUM‐149 cell lines. Significant elevations of the means of Arom Total Score (TS), ERβ TS and PR TS were found in the IMC group (p = 0.025, p = 0.038 and p = 0.037, respectively). Secondary IMC tumours expressed higher levels of Arom than primary IMC (p = 0.029). Non‐IMC PR‐ tumours contained higher levels of Arom than non‐IMC PR+ tumours (p = 0.007). After the addition of letrozole, the number of IMC and IBC cells dropped drastically. The overexpression of Arom found and the results obtained in vitro further support canine IMC as a model for the study of IBC and future approaches to the treatment of dogs with mammary cancer, and especially IMC, using Arom inhibitors. 相似文献
9.
10.
Infiltration characteristics for border strip irrigation at two sites with swelling clay soils were examined. Volume infiltrated was calculated from flow onto the field monitored with flow meters; depth of water in the soil estimated from soil samples taken before and after irrigation; and the advance profile which was used to calculate the volume infiltrated with time. Volume infiltrated was compared with volume of cracks before irrigation.Linear advance and observed crack closing supported the hypothesis that infiltration approached zero after about 10 min. Volume of cracks was less than 20% of the volume infiltrated. Wetting front was 3–10 times greater than depth of observed surface cracks. There was no significant correlation between intake opportunity time and depth of infiltration, but elevation irregularities were related to infiltration. 相似文献