全文获取类型
收费全文 | 2125篇 |
免费 | 104篇 |
国内免费 | 1篇 |
专业分类
林业 | 109篇 |
农学 | 132篇 |
基础科学 | 3篇 |
372篇 | |
综合类 | 146篇 |
农作物 | 281篇 |
水产渔业 | 186篇 |
畜牧兽医 | 844篇 |
园艺 | 33篇 |
植物保护 | 124篇 |
出版年
2023年 | 14篇 |
2022年 | 39篇 |
2021年 | 52篇 |
2020年 | 34篇 |
2019年 | 40篇 |
2018年 | 53篇 |
2017年 | 64篇 |
2016年 | 61篇 |
2015年 | 64篇 |
2014年 | 92篇 |
2013年 | 122篇 |
2012年 | 162篇 |
2011年 | 170篇 |
2010年 | 111篇 |
2009年 | 116篇 |
2008年 | 141篇 |
2007年 | 137篇 |
2006年 | 151篇 |
2005年 | 85篇 |
2004年 | 84篇 |
2003年 | 78篇 |
2002年 | 77篇 |
2001年 | 67篇 |
2000年 | 38篇 |
1999年 | 26篇 |
1998年 | 12篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 7篇 |
1994年 | 5篇 |
1993年 | 4篇 |
1992年 | 10篇 |
1991年 | 3篇 |
1990年 | 13篇 |
1989年 | 12篇 |
1988年 | 7篇 |
1987年 | 4篇 |
1985年 | 6篇 |
1981年 | 3篇 |
1978年 | 3篇 |
1976年 | 2篇 |
1975年 | 3篇 |
1974年 | 7篇 |
1973年 | 10篇 |
1971年 | 3篇 |
1970年 | 2篇 |
1968年 | 2篇 |
1966年 | 4篇 |
1949年 | 2篇 |
1929年 | 2篇 |
排序方式: 共有2230条查询结果,搜索用时 11 毫秒
981.
The vagus nerve is one route of transneural invasion for intranasally inoculated influenza a virus in mice 总被引:3,自引:0,他引:3
Matsuda K Park CH Sunden Y Kimura T Ochiai K Kida H Umemura T 《Veterinary pathology》2004,41(2):101-107
Intranasally inoculated neurotropic influenza viruses in mice infect not only the respiratory tract but also the central nervous system (CNS), mainly the brain stem. Previous studies suggested that the route of invasion of virus into the CNS was via the peripheral nervous system, especially the vagus nerve. To evaluate the transvagal transmission of the virus, we intranasally inoculated unilaterally vagectomized mice with a virulent influenza virus (strain 24a5b) and examined the distribution of the viral protein and genome by immunohistochemistry and in situ hybridization over time. An asymmetric distribution of viral antigens was observed between vagal (nodose) ganglia: viral antigen was detected in the vagal ganglion of the vagectomized side 2 days later than in the vagal ganglion of the intact side. The virus was apparently transported from the respiratory mucosa to the CNS directly and decussately via the vagus nerve and centrifugally to the vagal ganglion of the vagectomized side. The results of this study, thus, demonstrate that neurotropic influenza virus travels to the CNS mainly via the vagus nerve. 相似文献
982.
983.
Expression of the glutamine metabolism‐related proteins glutaminase 1 and glutamate dehydrogenase in canine mammary tumours 下载免费PDF全文
J.‐E. Ryu H.‐K. Park H.‐J. Choi H.‐B. Lee H.‐J. Lee H. Lee E.‐S. Yu W.‐C. Son 《Veterinary and comparative oncology》2018,16(2):239-245
Glutamine metabolism is an important metabolic pathway for cancer cell survival, and there is a critical connection between tumour growth and glutamine metabolism. Because of their similarities, canine mammary carcinomas are useful for studying human breast cancer. Accordingly, we investigated the correlations between the expression of glutamine metabolism‐related proteins and the pathological features of canine mammary tumours. We performed immunohistochemical and western blot analysis of 39 mammary tumour tissues. In immunohistochemical analysis, the expression of glutaminase 1 (GLS1) in the epithelial region increased according to the histological grade (P < .005). In the stromal region, complex‐type tumours displayed significantly higher GLS1 intensity than simple‐type tumours. However, glutamate dehydrogenase expression did not show the same tendencies as GLS1. The western blot results were consistent with the immunohistochemical findings. These results suggest that the expression of GLS1 is correlates with clinicopathological factors in canine mammary tumours and shows a similar pattern to human breast cancer. 相似文献
984.
IMAGING DIAGNOSIS—ACUTE MESENTERIC ISCHEMIA ASSOCIATED WITH HYPERTROPHIC CARDIOMYOPATHY IN A CAT 下载免费PDF全文
Miyoung Lee Nohwon Park Jaehwan Kim Donghyun Kim Hyunsoo Kim Kidong Eom 《Veterinary radiology & ultrasound》2015,56(4):E44-E47
A middle‐aged cat was presented with vomiting, diarrhea, and pelvic limb paresis. Radiography showed cardiomegaly, interstitial pulmonary infiltration, distended intestinal loops, and portal venous gas. Hypertrophic cardiomyopathy (HCM) was confirmed. On CT, thrombi were identified at the abdominal aorta, superior mesenteric artery, bilateral renal arteries, and cauda vena cava at the level of the iliac vein bifurcation. Dilated and gas‐filled loops of bowel with a “paper thin wall” were observed on CT images and were considered indicative of necrotic bowel. This case report describes the CT findings of acute mesenteric ischemia associated with HCM in a cat. 相似文献
985.
To enhance the strength while retaining the ductility of triptycene polyester, triptycene polyester/SWCNT nanocomposites were prepared. First, two different types of triptycene polyesters containing triptycenes that differ in size were synthesized and their mechanical and thermal characteristics were studied. Thermal analysis showed that the polyester containing the larger triptycene posed as a bigger hindrance factor to polymer chain-packing, resulting in lower crystallinity. Although the presence of triptycene interfered the packing of polymer chains, the increased size and amount of triptycene enhanced the thermal stability of the polymer. For the smaller sized triptycene-polyester/SWCNT composites, higher SWCNT content increased the stiffness and strength of the composite, but at the expense of the ductility. The increase in SWCNT content in the larger-sized triptycene polyester/SWCNT composites somewhat decreased the stiffness as well as the ductility of the polymer. 相似文献
986.
MJ Kim HJ Oh GA Kim JE Park EJ Park G Jang JC Ra SK Kang BC Lee 《Reproduction in domestic animals = Zuchthygiene》2012,47(Z4):115-119
The aim of this article is to review dog cloning research and to suggest its applications based on a discussion about the normality of cloned dogs. Somatic cell nuclear transfer was successfully used for production of viable cloned puppies despite limited understanding of in vitro dog embryo production. Cloned dogs have similar growth characteristics to those born from natural fertilization, with no evidence of serious adverse effects. The offspring of cloned dogs also have similar growth performance and health to those of naturally bred puppies. Therefore, cloning in domestic dogs can be applied as an assisted reproductive technique to conserve endangered species, to treat sterile canids or aged dogs, to improve reproductive performance of valuable individuals and to generate disease model animals. 相似文献
987.
Kim SP Yang JY Kang MY Park JC Nam SH Friedman M 《Journal of agricultural and food chemistry》2011,59(9):4570-4581
A new liquid rice hull smoke extract with a smoky aroma and sugar-like odor prepared by pyrolysis of rice hulls followed by liquefaction of the resulting smoke contained 161 compounds characterized by GC/MS. Antioxidative, antiallergic, and anti-inflammatory activities of the extract were assessed in vitro and in vivo. At pH 5, the extract inhibited 1-diphenyl-2-picrylhydrazyl (DPPH) free radicals and suppressed nitric oxide (NO) and β-hexosaminidase releases from lipopolysaccharide (LPS)-induced RAW264.7 mouse macrophage leukemia cells and ionophore A23187-stimulated RBL-2H3 rat basophilic cells without significant cytotoxicity. 12-O-Tetradecanolylphorbol-13-acetate (TPA) was applied to the ears of CD-1 mice to induce inflammation (edema), which was accompanied by increases in a series of biomarkers. Topical application of 1% of the extract as well as feeding mice a standard diet with 1% extract for two weeks significantly reduced the expression of biomarkers associated with the TPA-induced inflammation. These include tumor necrosis factor-α (TNF-α), IL-1β, interleukin-1β (IL-1β), interleukin-6 (IL-6), leukotriene B(4) (LTB(4)), prostaglandin E(2) (PGE(2)), myeloperoxidase (MPO). These in vitro and in vivo findings demonstrate the potential value of rice hull smoke extract derived from a major agricultural byproduct to serve as a new biomaterial for the improvement of food quality and safety and the environment. 相似文献
988.
989.
Dang QL Kim WK Nguyen CM Choi YH Choi GJ Jang KS Park MS Lim CH Luu NH Kim JC 《Journal of agricultural and food chemistry》2011,59(20):11160-11167
The methanol extract of Annona squamosa seeds was highly active against two phytoparasitic nematodes, Bursaphelenchus xylophilus and Meloidogyne incognita. It efficiently suppressed plant diseases, caused by Phytophthora infestans and Puccinia recondita. Ten annonaceous acetogenins (AAs) were isolated, and their chemical structures were identified by mass and nuclear magnetic resonance spectral data. Out of 10 substances, eight displayed strong in vitro nematicidal activity against B. xylophilus with LD(50) values ranging 0.006 to 0.048 μg/mL. Squamocin-G showed potent nematicidal activity against M. incognita. Squamocin, squamocin-G, and squamostatin-A also displayed potent in vitro and in vivo antifungal activities against P. infestans causing tomato late blight. In addition, squamostatin-A effectively controlled the development of wheat leaf rust caused by P. recondita. Our findings suggested that A. squamosa seeds and its bioactive AAs can be an alternative resource of a promising botanical nematicide and fungicide to control various plant diseases. 相似文献
990.
Ahmed glaucoma valve implantation with Ologen® Collagen Matrix for the surgical treatment of feline glaucoma 下载免费PDF全文
Kang‐hyo Park Joon‐Young Kim Seoung‐woo Choo Hun‐young Yoon Soon‐wuk Jeong 《Veterinary ophthalmology》2018,21(1):96-100
An Ahmed valve implantation with an Ologen® Collagen Matrix (Ologen® CM, Aeon Astron, Leiden, the Netherlands) was performed for the treatment of uncontrolled glaucoma in a cat. This cat was a 5‐year‐old castrated Russian Blue male with a 12‐week history of conjunctival hyperemia and mydriasis of the left eye. During the ophthalmic examination, the intraocular pressure (IOP) oculus sinister (OS) was 52 mmHg, and a narrow iridocorneal angle (ICA) was detected by gonioscopy. Medical treatment with Cosopt® (2% dorzolamide and 0.5% timolol) failed to decrease the IOP. The left eye still had vision, and an Ahmed valve implantation was performed. During the gonioimplantation, Ologen® CM was used to inhibit scar formation around the valve. Following the operation, the IOP was stable at an approximate average of 15 mmHg during the 7‐month follow‐up period, and vision in the left eye was retained without medication. An adequate subconjunctival filtering bleb was formed after 140 days. This is the first case report in which an Ahmed valve gonioimplant with an Ologen® CM has been used for the surgical treatment of glaucoma in a cat. 相似文献