首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   134篇
  免费   24篇
  国内免费   2篇
综合类   12篇
水产渔业   6篇
畜牧兽医   141篇
园艺   1篇
  2023年   7篇
  2022年   2篇
  2021年   4篇
  2020年   9篇
  2019年   8篇
  2018年   7篇
  2017年   4篇
  2016年   9篇
  2015年   8篇
  2014年   12篇
  2013年   6篇
  2012年   8篇
  2011年   10篇
  2010年   5篇
  2009年   5篇
  2008年   7篇
  2007年   6篇
  2006年   4篇
  2005年   7篇
  2004年   8篇
  2003年   4篇
  2002年   4篇
  2001年   2篇
  2000年   4篇
  1999年   2篇
  1998年   4篇
  1995年   1篇
  1994年   2篇
  1990年   1篇
排序方式: 共有160条查询结果,搜索用时 15 毫秒
151.
OBJECTIVE: To determine the long-term toxicity of an intravitreal device releasing continuous cyclosporinee A (CsA) in normal eyes of horses by evaluating clinical signs, electroretinography, and histopathology. Animals Studied Ten adult horses with normal ophthalmic examinations were used in this study Procedure(s) Four horses had one eye implanted with a CsA device, and six horses had the right eye implanted with a CsA-containing device (10 eyes with CsA in total) and the left eye (six eyes in total) with the device without drug (control). The implants were placed in the vitreous of the eyes through a sclerotomy 1 cm posterior to the limbus in the dorso-temporal quadrant of the eye. Scotopic electroretinograms were performed prior to implantation and at 1 week, and at 1, 3, 6, 9, and 12 months postimplantation. Two of the unilaterally implanted horses were euthanized at 1 weeks postimplantation, and two at 6 weeks postimplantation. Two of the bilaterally implanted horses were euthanized at 6 months, two at 9 months, and two at 12 months postimplantation. At euthanasia, the eyes were removed, aqueous and vitreous humor aspirated, and tissues fixed in 10% buffered formalin and processed for histopathology. CsA concentrations were measured by high pressure liquid chromatography in the aqueous and vitreous humors, and in peripheral blood. RESULTS: The devices were tolerated well in 14 of 16 eyes. There was minimal postoperative inflammation in most eyes, with a normal appearance within 7 days. In two eyes implanted with the CsA device, severe inflammation resulted in phthisis bulbi by 28 days. One of these eyes exhibited suspected bacterial endophthalmitis, and one had a sterile endophthalmitis and cataract presumably from trauma to the lens during implantation. In the other 14 eyes, no change was observed in the scotopic electroretinograms (ERG) from preoperative results, and no significant differences between the right (CsA) and left (control device) eyes were observed. CsA levels in the aqueous and vitreous humor, and peripheral blood were below the detection limit of the HPLC. Histologic findings revealed only a mild lymphoplasmacytic cellular infiltrate in the ciliary body and pars plana near the implantation site. CONCLUSIONS: The CsA devices were well tolerated with no long-term complications from the implants themselves. However, complications may occur from inadvertent implantation trauma or contamination during surgery. The long-term safety of the device may make it useful for delivery of CsA in the control of equine recurrent uveitis.  相似文献   
152.
利用含早卵泡期山羊血清或中黄体期山羊血清的培养液,对山羊腺垂体细胞进行24h体外培养,并在培养液中分别加入阿片受体兴奋剂——盐酸吗啡和其拮抗剂——盐酸纳洛酮,研究了类阿片肽对山羊垂体细胞分泌促性腺激素功能的影响。结果表明,在两种培养条件下,吗啡或纳洛酮对垂体促性腺激素的分泌均无显著影响(P>0.05)。因而认为,在山羊,类阿片肽对垂体细胞促性腺激素的分泌无直接调节作用。  相似文献   
153.
An 8‐year‐old, brachycephalic, mixed breed cat underwent full mouth tooth extractions for the treatment of tooth root abscessation. Subsequently, the cat developed anterior uveitis refractory to topical therapy that eventually necessitated enucleation. Actinomyces species were isolated from both the tooth root abscesses and the anterior chamber after enucleation. Histopathology of the enucleated eye revealed panophthalmitis with abundant intralesional bacteria morphologically consistent with Actinomyces. Between the time of tooth root extraction and enucleation (20 weeks), the cat was diagnosed with hyperthyroidism and treated with oral steroids for inflammatory bowel syndrome. We believe this report represents a rare case of endogenous endophthalmitis secondary to dental disease, possibly precipitated by concurrent immunosuppression.  相似文献   
154.
155.
Unilaterally swollen eyes were histopathologically characterized in four MG-W gerbils. The primary lesions resided in the anterior segment of the eye where neural crest cells play a critical role in embryonic development. They included indistinct filtration angle, unformed canal of Schlemm, hypoplastic iris, and ciliary body. The findings noted in the retina, optic nerve, optic tract, and lateral geniculate nucleus were consistent with the lesions induced following the persistent elevation of intraocular pressure as a result of insufficient drainage of aqueous humor. Thus, the present cases observed in the eyes of MG-W gerbils exemplified the anterior segment dysmorphogenesis associated with inadequate neural crest migration or differentiation, leading to subsequent glaucoma.  相似文献   
156.
为研究鸡胚垂体中生长激素细胞的发生及其在发育过程中的变化 ,分别在鸡胚发育的第 3 5~ 2 0 5天采集鸡胚垂体 ,用免疫组织化学方法研究鸡胚垂体中生长激素细胞的发生和细胞形态、数量、在垂体中的分布特点和在发育过程中的变化。结果表明 ,鸡胚发育中期第 9 5天可观察到少量的生长激素阳性细胞散在分布于垂体后叶 ,细胞多排列成索状或团状 ,细胞之间边界不清 ,细胞核较大。在鸡胚发育的第 12 5天以后 ,生长激素细胞的细胞浆与细胞核比值逐渐变小 ,且均匀分布于腺垂体的后叶。生长激素细胞数在鸡胚发育的第 12 5天之后显著升高 (P <0 0 1) ,在鸡胚发育的第 16 5天 ,生长激素细胞占垂体细胞总数的 9 4 %。以上结果证明鸡胚垂体中生长激素细胞增殖和分化过程主要发生在发育的中期至出壳之前 ,而生长激素细胞的分泌功能在鸡胚发育的后期最为活跃。  相似文献   
157.
Congenitally primary hypothyroid growth-retarded (grt) mice exhibit a characteristic growth pause followed by delayed onset of pubertal growth. We characterized the developmental pattern of somatotropes, lactotropes and thyrotropes in the anterior pituitary, as well as plasma levels of their secretory hormones, in grt mice. Compared with normal mice, the weight of grt pituitary gland was similar at 8 weeks of age but significantly heavier after 12 weeks of age. Compared with normal mice, there were significantly fewer somatotropes in the grt pituitary until 8 weeks of age, but the number gradually increased up to 48 weeks. The number of lactotropes in grt mice was consistently lower than that in normal mice from 2 through 48 weeks, whereas the number of thyrotropes in the grt pituitary was consistently higher than in the normal pituitary. Thyrotropes in the grt pituitary exhibited hypertrophy and hyperplasia with less intensive thyroid-stimulating hormone (TSH) immunoreactivity than normal thyrotropes. In normal mice, the sum of the relative proportions of these cells plateaued at 8 weeks, where it remained up to 48 weeks of age. In grt mice, these proportions almost reached normal levels at 12 weeks of age but gradually declined after 24 weeks. Plasma growth hormone concentrations did not differ between grt and normal mice until 24 weeks of age. Compared with normal mice, grt mice exhibited significantly lower plasma prolactin and thyroxine levels but higher TSH levels. These findings indicate that development of somatotropes, lactotropes and thyrotropes in grt mice is impaired, being followed by altered hormone secretion.  相似文献   
158.
Intraocular choristomas are rare anomalies in domestic animals and are often associated with multiple ocular malformations. A Thoroughbred foal presented for ocular abnormalities and was diagnosed with microphthalmia, corneal dermoids, severe anterior segment dysgenesis (including glandular choristomas), aphakia, retinal dysplasia, and optic nerve hypoplasia. Morphological, histochemical, and immunohistochemical comparisons were made between ocular choristomatous tissues from this foal and lacrimal gland, third eyelid gland, nasopharynx, trachea, and lacrimal sac/nasolacrimal duct from normal horses. Morphologically the choristomatous tissues (glands and epithelium lining the anterior segment) were most similar to the lacrimal sac. Histochemistry of glandular components found the glands associated with the lacrimal sac/nasolacrimal duct to be serous, as was the glandular intraocular choristomas. Our findings suggest that the origin of intraocular glandular choristomas in this case is from the lacrimal sac.  相似文献   
159.
A three-month-old, male intact Norwegian forest cat without any clinical signs was referred to the cardiology service of the author’s teaching hospital for evaluation of a cardiac murmur. The murmur was systolic with an intensity of 4 out of 6 with the point of maximal intensity at the left heart base. Echocardiography revealed a moderate mitral valve regurgitation and a moderate dynamic left ventricular outflow tract obstruction both resulting from systolic anterior motion of the mitral valve (SAM). Moreover, left ventricular concentric hypertrophy was noted. Oral atenolol therapy was initiated. Recheck examination 3.5 months later revealed unchanged murmur characteristics in the still asymptomatic kitten. Echocardiography showed no SAM, but there was a severe fixed aortic stenosis apparent caused by a discrete supravalvular lesion, 4 mm distal to the valve, with an hourglass morphology. Supravalvular aortic stenosis is a rare congenital anomaly in cats, which has not been reported antemortem yet.  相似文献   
160.

Objective

To determine the prevalence of ocular disease in draft horses in the United States.

Animals

Draft horses of various breeds and ages.

Procedure

Nondilated ophthalmic examination was performed using slit lamp biomicroscopy and indirect ophthalmoscopy. Intraocular pressures were measured when possible.

Results

One hundred sixty-five draft horses were examined. Age range: 10 days to 33 years (mean 10.8 years, median 10 years); 87 geldings (52.7%), 71 mares (43.0%), 7 stallions (4.2%); 64 Percherons (38.8%), 51 Belgians (30.9%), 29 Clydesdales (17.6%), 15 Shires (9%), and 6 other draft breed (3.6%). Intraocular pressure: mean 24.7 mmHg OD, range 13-37 mmHg; mean 25.0 mmHg OS, range 11-37 mmHg. Vision-threatening disease was present in 9 horses (5.5%): complete cataracts 1, post-traumatic optic nerve atrophy 1, uveitis and secondary glaucoma 1, retinal detachment 1, large chorioretinal scar 3, phthisis bulbi 2. Non-vision-threatening ocular disease was present in 56 horses (33.9%) involving one or more ocular structures: eyelid trauma/notch defect 14 (8.5%), SCC-type adnexal lesions 12 (7.3%), corneal scars 16 (9.7%), keratitis 6 (3.6%), corpora nigra cyst 15 (9.1%), incipient/punctate cataract 50 (30.3%), vitreous degeneration 10 (6.1%), asteroid hyalosis 1, “bullethole” chorioretinal scars 3, RPE coloboma 1. Linear keratopathy was present in 28 horses (17%) with 2/28 having concurrent vision threatening ocular disease.

Conclusions

Ocular abnormalities, in particular minor cataracts, were relatively common in this population, but not typically vision-threatening. Additionally, this survey demonstrated a greater prevalence of linear keratopathy in draft horses compared with reports in other breeds; however, it does not appear to be associated with concurrent ocular disease.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号