全文获取类型
收费全文 | 285篇 |
免费 | 12篇 |
专业分类
林业 | 23篇 |
农学 | 3篇 |
基础科学 | 1篇 |
61篇 | |
综合类 | 9篇 |
农作物 | 33篇 |
水产渔业 | 39篇 |
畜牧兽医 | 97篇 |
园艺 | 6篇 |
植物保护 | 25篇 |
出版年
2024年 | 2篇 |
2023年 | 3篇 |
2022年 | 8篇 |
2021年 | 11篇 |
2020年 | 12篇 |
2019年 | 17篇 |
2018年 | 4篇 |
2017年 | 12篇 |
2016年 | 11篇 |
2015年 | 5篇 |
2014年 | 9篇 |
2013年 | 20篇 |
2012年 | 21篇 |
2011年 | 18篇 |
2010年 | 13篇 |
2009年 | 7篇 |
2008年 | 23篇 |
2007年 | 17篇 |
2006年 | 15篇 |
2005年 | 17篇 |
2004年 | 15篇 |
2003年 | 10篇 |
2002年 | 8篇 |
2001年 | 2篇 |
2000年 | 2篇 |
1999年 | 2篇 |
1998年 | 3篇 |
1996年 | 2篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1983年 | 1篇 |
1979年 | 1篇 |
排序方式: 共有297条查询结果,搜索用时 12 毫秒
71.
Acosta TJ Hayashi KG Matsui M Miyamoto A 《The Journal of reproduction and development》2005,51(2):273-280
Increase in the blood supply to individual follicles appears to be associated with follicular growth rates and the ability to become the dominant follicle, while reduced thecal vascularity appears to be closely associated with follicular atresia. Therefore, this study aimed to determine the real-time changes in the vascularity of the follicle wall during the first follicular wave in cycling Holstein cows. Normally cycling and lactating cows (n=5) were examined by transrectal color Doppler ultrasonography (the sensitivity for velocity: > 2 mm/sec) to determine the changes in the vasculature of the follicle wall (presence or absence of blood flow) and the diameter of follicles. A new follicular wave and ovulation were induced by GnRH injection at 48 h after an injection of PGF2alpha analogue. The ovaries were scanned daily for 7 days after GnRH injection. Follicles >2.5 mm were classified into 3 groups by the changes in diameter as follows: 1) largest follicle, 2) second largest follicle, and 3) small follicles, which included all other follicles >2.5 mm. Before the follicle selection, there was no significant difference in the percentage of follicles with detectable blood flow between the subsequently determined largest and second largest follicles. After the follicle selection, the percentage of follicles with detectable blood flow significantly decreased among the second largest follicles. In addition, small follicles with detectable blood flow kept larger diameters than those without detectable blood flow from one day before the occurrence of follicle selection. It is likely that maintenance of follicle vasculature and appropriate blood supply to the larger follicles is essential for follicle dominance. In small follicles, the presence of blood flow within the wall also appears to be required for recruitment. Consequently, the data suggest that the change of the blood supply to an individual follicle closely relates to the dynamics of follicular growth in the first follicular wave in the cow. 相似文献
72.
Single-step purification and evaluation of recombinant BP26 protein for serological diagnosis of Brucella ovis infection in rams 总被引:1,自引:0,他引:1
Zygmunt MS Baucheron S Vizcaino N Bowden RA Cloeckaert A 《Veterinary microbiology》2002,87(3):213-220
To investigate the value of the BP26 protein in the serological diagnosis of ovine brucellosis caused by Brucella ovis, recombinant BP26 protein was produced in Echerichia coli and purified for use in an indirect enzyme-linked immunosorbent assay (I-ELISA). The majority of the recombinant protein was recovered from the supernatant of sonicated recombinant E. coli cells in a soluble form. This facilitated the purification of the recombinant BP26 protein which was achieved by using ion-exchange chromatography. After one step of purification, the purity of the recombinant BP26 protein was analyzed by using SDS-PAGE, Coomassie blue staining, and Western blot with a monoclonal antibody (MAb) directed against the BP26 protein. The degree of purity appeared satisfactory so that it could be directly used in I-ELISA. Although the recombinant BP26-ELISA appeared less useful than I-ELISA using the B. ovis hot saline (HS) extract as antigen, the high number of sera from B. ovis infected rams found positive (90%) in the recombinant BP26-I-ELISA indicated that the BP26 protein may be an additional suitable antigen for serological diagnosis of B. ovis infection in rams. 相似文献
73.
Kojima AY Kobayashi S Acosta TJ Kudo M Miyamoto A Takagi M Miyazawa K Sato K 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2002,64(2):119-122
Microdialysis System (MDS) is a novel technique used for investigation of molecule secretion between different cell populations. Local hormonal secretion at follicular wall has been still unclear. This MDS study was used to determine progesterone (P4), androstenedione (A4), estradiol-17beta (E2) and Prostaglandin F2alpha (PGF2alpha) release in mare pre-ovulatory follicles. Follicles larger than 30 mm were isolated from the ovary and follicular fluid aspirated for hormone assay. Follicular fluid collected from small, middle and large follicles were analyzed by EIA. The concentrations of P4 and PGF2alpha were similar among the different sizes of follicles. The release of A4 was observed in middle and large follicles. E2 concentration was observed in middle follicles and was higher in large follicles compared with middle follicles. Follicular wall was cut and incubated for MDS and when LH was infused, there was an increase in P4 and A4 release. PGF2alpha release was considerably high after LH infusion compared to the control group. Infusion of PGF2alpha increased P4 and A4 release but there was no change in E2 release. This results suggest that in pre-ovulatory follicles, LH stimulates theca interna cells and also PGF2alpha seemed to have a mediator role to induce steroid hormone production and luteinization of follicular cells. The nature of the mechanisms involved in selection of large follicles is still a perplexing research problem in reproduction. 相似文献
74.
Lopez-Rodriguez Norma A. Gaytán-Martínez Marcela de la Luz Reyes-Vega María Loarca-Piña Guadalupe 《Plant foods for human nutrition (Dordrecht, Netherlands)》2020,75(4):447-457
Plant Foods for Human Nutrition - Alternative therapies, such as phytotherapy, are considered to improve the health status of people with chronic non-communicable diseases (CNCDs). In this regard,... 相似文献
75.
76.
El Aamri F Padilla D Acosta F Caballero M Roo J Bravo J Vivas J Real F 《Journal of fish diseases》2010,33(11):901-905
This work describes the first isolation of Streptococcus iniae in red porgy, Pagrus pagrus (L.), and the first European isolation of this pathogen in gilthead seabream, Sparus aurata (L.). In both farmed fish species, infection resulted in lethargy, anorexia, abnormal swimming, exophthalmia and sudden death, with mortality rates of over 25% in red porgy and 10% in gilthead seabream. Beta-haemolytic Gram-positive cocci, catalase negative and oxidase negative, were isolated in pure culture from internal organs. Conventional and rapid identification systems, and 16S rRNA gene partial sequencing were used to identify the causative agent of the natural disease. LD50 trials were carried out to show the virulence of this isolated strain in these species, with values of 1.7 × 104 CFU per fish in red porgy and 1.32 × 105 CFU per fish in gilthead seabream. The most prominent lesions were meningoencephalitis and multifocal infiltration of macrophage cells in the kidney and spleen. 相似文献
77.
V. Gimeno J.P. Syvertsen M. Nieves I. Simón V. Martínez F. García-Sánchez 《Scientia Horticulturae》2009
Irrigation with saline water is one of the major problems in citrus crop in arid and semi-arid regions. Because rootstock and fertilization play an important role in citrus salt tolerance, we investigated the influence of the nitrogen fertilization and rootstock on salt tolerance of 2-year-old potted Fino 49 lemon trees. For that, trees grafted on Citrus macrophylla (M) or Sour orange (SO) rootstocks were watered for 12 weeks with complete nutrient solution containing either 0 mM NaCl (control, C), 50 mM NaCl (S), 50 mM NaCl with an additional 10 mM potassium nitrate (S + N), or 50 mM NaCl with a 1% KNO3 (S + Nf) foliar spray application. Trees on M were more vigorous than trees on SO and saline treatments reduced leaf growth similarly in trees on both rootstocks. Trees on SO had a lower leaf Cl− and Na+ concentration than those on M. Additional soil nitrogen (S + N) decreased leaf Cl− concentration and increased leaf K+ concentration in salinized trees on both rootstocks. However, the salinity-induced reduction leaf growth was similar in S + N and S trees. This was due to osmotic effect, beside leaf Cl− and Na+ toxicity, played an important role in the growth response of Fino 49 lemon to the salt stress. Additional foliar nitrogen in the S + Nf treatment also reduced leaf Cl− concentration relative to the S treatment but trees from S + Nf treatment had the lowest leaf growth. Net assimilation of CO2 (ACO2), stomatal conductance (gs) and plant transpiration were reduced similarly in all three salt treatments, regardless rootstock. Salinity reduced leaf water and osmotic potential such that leaf turgor was increased. Thus, the salinity-induced ACO2 reductions were not due to loss of turgor but rather due to high salt ion accumulation in leaves. 相似文献
78.
The level of infection by infectious pancreatic necrosis virus (IPNV) of kidney macrophages from 12 asymptomatic carrier Atlantic salmon post-smolts was studied. Kidney leucocytes were fractionated on 34/51% Percoll gradients, allowed to adhere to plastic wells overnight, washed to remove non-adherent cells and cultured for up to 7 days with or without renewal of medium on day 3. On day 1, supernatants were harvested, macrophages were counted, lysed and IPNV in the supernatants and lysates was titred in chinook salmon embryo (CHSE-214) cells. The multiplicity of infection ranged between 1:2.2 and 1:7.4 (virus:macrophages). On day 3, the titres of IPNV in macrophage lysates decreased and in wells where the medium was renewed on day 3, IPNV was no longer detectable on day 7. In the supernatants, one fish was positive for IPNV on day 1, four fish on day 3 but none were detectably positive on day 7. In parallel wells in which the medium was not renewed, on day 7 IPNV was detected in macrophage lysates of three fish and the supernatants were also IPNV positive in two of these fish. This suggests that virus might be shed from infected macrophages and then reinfect other macrophages. When macrophages were serially diluted in wells and cultured for 24 h, IPNV could be cultured from macrophage lysates of wells containing between two and 70 macrophages. These results indicate that a very high proportion of the adherent kidney macrophages must be infected with very few non-replicating virions. 相似文献
79.
80.