全文获取类型
收费全文 | 1332篇 |
免费 | 40篇 |
国内免费 | 109篇 |
专业分类
林业 | 5篇 |
农学 | 48篇 |
基础科学 | 14篇 |
104篇 | |
综合类 | 451篇 |
农作物 | 14篇 |
水产渔业 | 15篇 |
畜牧兽医 | 812篇 |
园艺 | 6篇 |
植物保护 | 12篇 |
出版年
2024年 | 2篇 |
2023年 | 7篇 |
2022年 | 14篇 |
2021年 | 48篇 |
2020年 | 59篇 |
2019年 | 43篇 |
2018年 | 26篇 |
2017年 | 17篇 |
2016年 | 34篇 |
2015年 | 46篇 |
2014年 | 98篇 |
2013年 | 94篇 |
2012年 | 72篇 |
2011年 | 92篇 |
2010年 | 66篇 |
2009年 | 88篇 |
2008年 | 81篇 |
2007年 | 125篇 |
2006年 | 74篇 |
2005年 | 54篇 |
2004年 | 48篇 |
2003年 | 20篇 |
2002年 | 25篇 |
2001年 | 21篇 |
2000年 | 36篇 |
1999年 | 32篇 |
1998年 | 24篇 |
1997年 | 19篇 |
1996年 | 13篇 |
1995年 | 19篇 |
1994年 | 18篇 |
1993年 | 12篇 |
1992年 | 10篇 |
1991年 | 6篇 |
1990年 | 10篇 |
1989年 | 13篇 |
1988年 | 8篇 |
1987年 | 5篇 |
1977年 | 1篇 |
1975年 | 1篇 |
排序方式: 共有1481条查询结果,搜索用时 15 毫秒
51.
Jiro Sonoda Yuki Seki Atsushi Hakura Satoru Hosokawa 《Journal of toxicologic pathology》2015,28(2):109-120
Benzo[a]pyrene (BP) is mutagenic but noncarcinogenic in the murine colon. Recently, we reported rapid induction of colonic tumors by treatment of CD2F1 mice with BP (125 mg/kg for 5 days) followed by a colitis inducer, dextran sulfate sodium (DSS) (4% in drinking water for 1 or 2 weeks). However, there are no reports on detailed time course and histopathological features of colonic proliferative lesions in this model. Here, we show the detailed time course of colonic dysplasia, adenoma and adenocarcinoma induced by treatment with BP, DSS, and a combination of the two (BP/DSS). In the colon of mice exposed to BP/DSS, 14.6 dysplastic foci per mouse were present one week after DSS treatment (week 4). The number of dysplastic foci decreased with time to 3.1 at week 9 and thereafter remained almost constant. At week 4, 1.5 adenocarcinomas were also observed, with a marked increase in numbers with time, reaching 29.3 at week 14. In contrast, the number of dysplastic foci induced by DSS alone showed a time course similar to that following BP/DSS treatment; however, only a few tumors appeared. Neither dysplastic foci nor neoplastic lesions were induced by BP only. In mice exposed to BP/DSS, β-catenin was demonstrated immunohistochemically in the nucleus and/or cytoplasm of the tumor cells, and this translocation from the cell membrane was evident in subsets of dysplastic foci. In dysplastic foci induced by DSS alone, β-catenin was absent in the nucleus/cytoplasm. These finding suggest that aberrant β-catenin accumulation in dysplastic foci is associated with tumor progression in this BP/DSS model. 相似文献
52.
Ji-Yeong YEON Sung-Hun MIN Hyo-Jin PARK Jin-Woo KIM Yong-Hee LEE Soo-Yong PARK Pil-Soo JEONG Humdai PARK Dong-Seok LEE Sun-Uk KIM Kyu-Tae CHANG Deog-Bon KOO 《The Journal of reproduction and development》2015,61(2):81-89
Mitochondria are highly dynamic organelles that undergo constant fusion/fission as well as activities orchestrated by large dynamin-related GTPases. These dynamic mitochondrial processes influence mitochondrial morphology, size and function. Therefore, this study was conducted to evaluate the effects of mitochondrial fission inhibitor, mdivi-1, on developmental competence and mitochondrial function of porcine embryos and primary cells. Presumptive porcine embryos were cultured in PZM-3 medium supplemented with mdivi-1 (0, 10 and 50 μM) for 6 days. Porcine fibroblast cells were cultured in growth medium with mdivi-1 (0 and 50 μM) for 2 days. Our results showed that the rate of blastocyst production and cell growth in the mdivi-1 (50 μM) treated group was lower than that of the control group (P < 0.05). Moreover, loss of mitochondrial membrane potential in the mdivi-1 (50 μM) treated group was increased relative to the control group (P < 0.05). Subsequent evaluation
revealed that the intracellular levels of reactive oxygen species (ROS) and the apoptotic index were increased by mdivi-1 (50 μM) treatment (P < 0.05). Finally, the expression of mitochondrial fission-related protein (Drp 1) was lower in the embryos and cells in the mdivi-1-treated group than the control group. Taken together, these results indicate that mdivi-1 treatment may inhibit developmental competence and mitochondrial function in porcine embryos and primary cells. 相似文献
53.
导致猪免疫抑制的因素 总被引:3,自引:0,他引:3
导致猪免疫抑制的因素,存在广泛,防不胜防,常常导致其它疾病的免疫失败,在临床上危害严重。文章从理化、药物、营养、不良应激刺激、传染性疾病方面阐述了引起猪免疫抑制的因素,以期在养猪中预防或降低其发生率。 相似文献
54.
This study aimed to validate the use of an automated chemiluminescent immunoassay analyser for salivary testosterone measurements in growing pigs and study how circadian pattern during daytime and stress can influence its values. The test method had intra- and inter-assay coefficient of variation lower than 10%. The method showed good linearity and recovery, and detection limits were low enough to detect salivary testosterone levels. No significant differences were observed in testosterone concentrations at different sampling time, and age and gender did not influence circadian pattern. In addition, this assay was used to quantify testosterone in two models of acute stress and, in both cases, significant increases (P < 0.01) in salivary testosterone were detected. Therefore, the automated assay system tested for porcine testosterone determinations would be suitable for its use in saliva samples and, furthermore, salivary testosterone levels could be used as a possible marker of acute stress in pigs. 相似文献
55.
Pharmacokinetics of gamithromycin after intravenous and subcutaneous administration in pigs 总被引:1,自引:0,他引:1
H. Wyns E. MeyerE. Plessers A. WatteynS. De Baere P. De BackerS. Croubels 《Research in veterinary science》2014
The aim of this study was to investigate the pharmacokinetic properties of gamithromycin in pigs after an intravenous (i.v.) or subcutaneous (s.c.) bolus injection of 6 mg/kg body weight. The plasma concentrations of gamithromycin were determined using a validated high-performance liquid chromatography–tandem mass spectrometry method, and the pharmacokinetics were noncompartmentally analysed. 相似文献
56.
S. Ott L. Soler C.P.H. Moons M.A. Kashiha C. Bahr J. Vandermeulen S. Janssens A.M. Gutiérrez D. Escribano J.J. Cerón D. Berckmans F.A.M. Tuyttens T.A. Niewold 《Research in veterinary science》2014
Most commonly, salivary cortisol is used in pig stress assessment, alternative salivary biomarkers are scarcely studied. Here, salivary cortisol and two alternative salivary biomarkers, haptoglobin and chromogranin A were measured in a pig stress study. Treatment pigs (n = 24) were exposed to mixing and feed deprivation, in two trials, and compared to untreated controls (n = 24). Haptoglobin differed for feed deprivation vs control. Other differences were only found within treatment. Treatment pigs had higher salivary cortisol concentrations on the mixing day (P < 0.05). Chromogranin A concentrations were increased on the day of refeeding (P < 0.05). Haptoglobin showed a similar pattern to chromogranin A. Overall correlations between the salivary biomarkers were positive. Cortisol and chromogranin A were moderately correlated (r = 0.49, P < 0.0001), correlations between other markers were weaker. The present results indicate that different types of stressors elicited different physiological stress responses in the pigs, and therefore including various salivary biomarkers in stress evaluation seems useful. 相似文献
57.
Yimei Cao Zengjun Lu Dong Li Pengju Fan Pu Sun Huifang Bao Yuanfang Fu Pinghua Li Xingwen Bai Yingli Chen Baoxia Xie Zaixin Liu 《Veterinary microbiology》2014,168(2-4):294-301
Epitope-based vaccines are always questioned for their cross-protection against the antigenically variable foot-and-mouth disease virus (FMDV). In this study, we proved the cross-protection effect of a multi-epitope vaccine incorporated with poly(I:C) against three topotypes of O type FMDV. A total of 45 naïve pigs were vaccinated with different doses of multi-epitope protein vaccine incorporated with poly(I:C). At 28 days post-vaccination, 45 vaccinated and 6 unvaccinated control pigs (two pigs for each group) were challenged with three topotypes of virulent O type FMDV, namely, O/Mya/98 (Southeast Asia topotype), O/HN/CHA/93 (Cathay topotype) and O/Tibet/CHA/99 (PanAsia topotype) strains. All unvaccinated pigs developed generalised FMD clinical signs. Results showed that all pigs (n = 15) conferred complete protection against the O/Mya/98 and O/HN/CHA/93 FMDV strains, 11 of which were protected against the O/Tibet/CHA/99 FMDV strain. The 50% protective dose values of the vaccine against the O/Mya/98, O/HN/CHA/93 and O/Tibet/CHA/99 FMDV strains were 15.59, 15.59 and 7.05, respectively. Contact challenge experiment showed that transmission occurred from the donors to the unvaccinated but not to vaccinated pigs. These results showed that vaccination with multi-epitope protein vaccine incorporated with poly(I:C) can efficiently prevent FMD in pigs. 相似文献
58.
59.
C. J. Bodaan L. Panizzi A. J. Stewart E. Cypher L. Whitfield C. B. Riley 《Equine Veterinary Education》2014,26(7):341-344
A 5‐month‐old Warmblood cross colt was presented with focal swelling of the ventral abdomen extending from the umbilicus to the scrotum in the absence of colic signs. Palpation and ultrasound examination revealed the presence of incarcerated large intestine within the subcutaneous space adjacent to the caudal ventral abdomen and prepuce. Surgery was performed and revealed that the umbilical hernia sac had ruptured, and confirmed that the left dorsal and ventral colon were present in the subcutaneous space. The mild degree of vascular compromise of the large colon did not necessitate resection and so it was replaced within the abdomen. The abdominal wall defect was closed and the subcutaneous dead space was reduced by using a walking suture pattern. Herniation of the large colon through the umbilicus with dissection through the subcutaneous tissues of the ventral abdominal wall and prepuce has not been previously reported in foals. Ultrasonography permits differentiation of herniated small intestine from large intestine. 相似文献
60.