全文获取类型
收费全文 | 464篇 |
免费 | 71篇 |
国内免费 | 61篇 |
专业分类
林业 | 3篇 |
农学 | 3篇 |
2篇 | |
综合类 | 80篇 |
农作物 | 5篇 |
水产渔业 | 205篇 |
畜牧兽医 | 256篇 |
园艺 | 1篇 |
植物保护 | 41篇 |
出版年
2023年 | 9篇 |
2022年 | 9篇 |
2021年 | 25篇 |
2020年 | 32篇 |
2019年 | 28篇 |
2018年 | 22篇 |
2017年 | 34篇 |
2016年 | 35篇 |
2015年 | 21篇 |
2014年 | 26篇 |
2013年 | 13篇 |
2012年 | 36篇 |
2011年 | 38篇 |
2010年 | 21篇 |
2009年 | 29篇 |
2008年 | 22篇 |
2007年 | 15篇 |
2006年 | 18篇 |
2005年 | 17篇 |
2004年 | 24篇 |
2003年 | 24篇 |
2002年 | 13篇 |
2001年 | 11篇 |
2000年 | 11篇 |
1999年 | 8篇 |
1998年 | 5篇 |
1997年 | 9篇 |
1996年 | 1篇 |
1995年 | 6篇 |
1994年 | 4篇 |
1993年 | 3篇 |
1992年 | 5篇 |
1991年 | 3篇 |
1990年 | 4篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1987年 | 4篇 |
1986年 | 2篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1956年 | 1篇 |
排序方式: 共有596条查询结果,搜索用时 31 毫秒
181.
给小白鼠背部按一定剂量浇泼阿维菌素浇泼剂及倍硫磷浇泼剂,于8h、24h、35h将用药小鼠处死,背部(用药部位)取材,分别进行光学显微镜及透射电子显微镜观察。结果,阿维菌素浇泼剂按0.004ml/10g浇泼,约有20%的表皮上皮细胞角化及脱落,而按0.1ml/10g浇泼,约有40%的表皮上皮细胞完全角化及脱落、坏死,真皮胶原纤维减少、疏松、染色较浅泼有充血和出血现象;毛囊外根鞘上皮细胞浆内出现大量空泡、间质细胞内质网有轻度的扩张。倍硫磷浇泼剂按0.0413ml/10g浇泼,可见上皮细胞轻度角化、真皮胶原纤维淡染、疏松并有空泡变性及散在的红细胞;毛囊外根鞘及内根鞘细胞浆内有大量空泡、间质中胶原纤维染色不均。按0.1ml/10g背部浇泼透皮吸收促进剂,经不同时间取材进行光镜及电镜观察,未发现明显的组织结构变化。 相似文献
182.
Over 100 000 goats were grazing freely in isolated herds of 100 to 600 goats in a mountainous area of more than 2000 km2; to the north-east of Darab City in Fars Province in southern Iran. Twenty to fifty percent of the goats in this area were infected with besnoitiosis. Sheep, cattle and donkeys grazing in the same area showed no clinical manifestations of the infection. The diagnosis of the infection in the clinically suspected animals was confirmed by histological studies on skin biopsies from the ear tips and carpal and tarsal regions, and the distribution of this protozoon in the tissues and organs of this intermediate host was studied by post-mortem and histological examinations. Skin biopsies from the carpal and tarsal areas of 12% of clinically normal goats from the infected area were also lightly infected with besnoitia cysts. 相似文献
183.
Koratigere Parameshanayka Devaraja Ranjith Kumar Ellur Pankaj Ashok K. Singh Anumanahalli Puttasawamy Abhishek Gowda Anil Sirohi 《Plant pathology》2023,72(1):179-194
The rice root-knot nematode (RRKN), Meloidogyne graminicola, is one of the major pests of the rice–wheat cropping system. Resistance against M. graminicola in rice could be most valuable in alleviating this problem. The host response of 75 Oryza genotypes was examined at three day/night temperature regimes, 29/26°C, 34/31°C and 38/35°C, in Pluronic gel as well as in soil. Out of the 75 selected rice genotypes, only Zhenshan 97 B exhibited high resistance to this set of temperature regimes, with the least number of galls/root system. At 34/31°C, more second-stage juveniles (J2s) were hatched and J2 population densities in roots of the susceptible rice genotypes increased significantly compared with those of plants grown at the 29/26°C. In resistant genotypes, only a few J2s penetrated roots and developed into mature females. The histopathological studies revealed that in susceptible rice genotypes at high-temperature regimes, the multinucleate giant cells were well developed. The results presented in this study revealed that an increase in temperature had a significant effect on the resistance of rice genotypes and resistance appeared more pronounced in genotype Zhenshan 97 B. This resistant genotype can be used in marker-assisted selection to develop resistant elite cultivars. 相似文献
184.
Histopathology and oxidative stress analysis of concomitant misoprostol and
celecoxib administration
Derek E. Murrell James W. Denham Sam Harirforoosh 《Journal of toxicologic pathology》2015,28(3):165-170
Nonsteroidal anti-inflammatory drugs (NSAIDs), non-selective or selective inhibitors of
cyclooxygenase (COX-1 and -2), reduce pain and inflammation associated with arthritic
diseases. Celecoxib, a COX-2-selective inhibitor providing decreased gastric injury
relative to non-selective NSAIDs, is commonly prescribed. Misoprostol, a prostaglandin
analog, supplements NSAID-inhibited prostaglandin levels. As concomitant celecoxib and
misoprostol administration has been shown to intensify renal adverse effects, this article
examined the influence of concomitant administration on hepatic histopathology, oxidative
stress, and celecoxib concentration. On days 1 and 2, rat groups (n = 6) were gavaged
twice daily (two groups with vehicle and two groups with 100 μg/kg misoprostol). From day
3 to day 9, one celecoxib dose (40 mg/kg) replaced a vehicle dose of one group and one
group received celecoxib in addition to misoprostol. Livers were harvested on day 10. No
hepatic abnormalities were observed denoting a lack of influence by either drug. Also no
change in mean biomarker levels was detected. The changes in hepatic celecoxib
concentration in the misoprostol-receiving group compared to control were not significant.
Thus misoprostol does not influence hepatic celecoxib effects in terms of histopathology,
oxidative stress, or celecoxib concentration level at the dosage and duration
examined. 相似文献
185.
Joseph C. Gerding Brian C. Gilger Stephanie A. Montgomery Alison B. Clode 《Veterinary ophthalmology》2015,18(6):502-509
A 7‐year‐old, 153.0‐kg American Miniature mare presented for evaluation of keratoconjunctivitis of the right eye (OD). A superior palpebral conjunctival mass and stromal keratitis were diagnosed. The incisional biopsy diagnosis was a presumptive corneal hemangiosarcoma. Transpalpebral enucleation was performed, and histopathologic evaluation confirmed angiosarcoma of the conjunctiva, cornea, and extraocular muscles. The horse developed progressive epistaxis and orbital swelling following surgery. A systemic workup was performed 3 months after enucleation, revealing regrowth within the orbit and marked cranial cervical lymphomegaly, suggestive of metastasis. Humane euthanasia was performed, and necropsy confirmed a locally invasive periorbital tumor with metastasis to the submandibular tissue, submandibular lymph node, and thoracic inlet. Histopathologic evaluation of necropsy specimens revealed polygonal to spindle neoplastic cells lining neoplastic vascular channels lacking erythrocytes. Immunohistochemically, the neoplastic cells labeled strongly positive for PROX‐1, vimentin, CD‐31, VEGF, weakly positive for factor VIII‐related antigen, and negative for collagen IV. Based on the clinical, histological, and immunohistochemical features of this tumor, a primary ocular lymphangiosarcoma with metastasis was diagnosed. 相似文献
186.
A 6‐year‐old female, spayed Collie was referred to the Western College of Veterinary Medicine for a 12‐month history of a progressive right corneal mass. A superficial keratectomy was performed and histopathology revealed a corneal melanocytoma with complete excision. There has been no recurrence of the neoplasm to date (12 months). This is the first known report of an isolated corneal melanocytoma in a canine. 相似文献
187.
肉鸭日粮亚硝酸盐中毒的血液学和组织病理学研究 总被引:1,自引:0,他引:1
健康樱桃谷鸭 15 6只 ,随机分为 6个组 ,每组 2 6只 ,试验设 6个处理 ,即对照组 ( 0组 )和 5个试验组( 1、2、3、4、5组 )。 6组饲喂的日粮中亚硝酸盐 (以NaNO2 计 )含量依次为 0、30 0、6 0 0、90 0、12 0 0、15 0 0mg kg。试验分两阶段饲养 ,试验结束时 ,每组随机抽 5只宰杀 ,采抗凝血进行血液学分析。剖检观察病理变化 ,计算脏器系数。制作病理组织学切片。结果表明 ,日粮中亚硝酸盐含量超过 90 0mg kg时 ,仅 4、5组部分脏器表现异常 ,心 体、肾 体比值改变极为显著 (P <0 .0 1)。血液中血红蛋白 (Hb)和高铁血红蛋白 (MHb)含量 2、3、4、5组与对照组比有显著差异 (P <0 .0 5 ) ,但MHb的绝对浓度并不高。因此 ,日粮中亚硝酸盐含量达到 90 0mg kg时 ,肉鸭健康状况明显受到不良影响 ,建议饲料中亚硝酸盐的无明显作用水平 (NOEL)定为 6 0 0mg kg。 相似文献
188.
189.
对含有抗叶锈基因Lr3、Lr26和Lr3+Lr26的小麦品种的组织病理学研究 总被引:1,自引:1,他引:1
本研究利用整叶违明染色法系统观察了含有Lr3、Lr26和Lr3+Lr26抗叶锈基因的小麦品种的组织病理学特征。结果表明,①含有不同基因的品种在叶锈菌侵入前的组织病理学表现没有差异;②Lr26具有慢锈特征并且在阿芙乐尔品种中对Lr3起上位作用;③寄主细胞坏死不是影响茵丝扩展的唯一因素,菌丝生长受抑制和寄主细胞的坏死不一定呈正相关;④利用某些组织病理学特征进行品种抗病性及其基因鉴定是可行的。 相似文献
190.
小麦品种及单基因系与叶锈菌互作的组织学和超微结构研究 总被引:5,自引:0,他引:5
应用荧光显微镜、微分干涉显微镜和电镜技术 ,比较研究了洛 10和冀麦 3号及其相应的单基因系L r2 6和 L r3Bg接种小麦叶锈菌后的组织病理学和超微结构特征。洛 10和 L r2 6的组织学表现极其相似 ,呈典型的早期过敏性坏死反应 ,导致侵染结构败育 ;冀麦 3号和 L r3Bg的组织学表现出一定差异 ,锈菌在 L r3Bg上的发展要快于呈现出慢锈特征的冀麦 3号。超微结构研究表明 ,小麦叶锈菌在洛 10和冀麦 3号上的发育受到了程度不同的抑制 ,表现为锈菌和寄主在细胞和亚细胞水平上有一系列变化。过敏性坏死反应和胼胝质的形成是 2个重要的抗锈机制。 相似文献