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   82篇
  免费   5篇
林业   4篇
农学   2篇
  16篇
综合类   5篇
农作物   9篇
水产渔业   4篇
畜牧兽医   46篇
植物保护   1篇
  2024年   1篇
  2022年   1篇
  2021年   3篇
  2019年   4篇
  2018年   2篇
  2017年   3篇
  2015年   1篇
  2014年   5篇
  2013年   1篇
  2012年   8篇
  2011年   5篇
  2010年   4篇
  2009年   4篇
  2008年   4篇
  2007年   5篇
  2006年   4篇
  2005年   11篇
  2004年   5篇
  2003年   4篇
  2002年   3篇
  1999年   1篇
  1998年   1篇
  1997年   1篇
  1995年   1篇
  1994年   1篇
  1991年   2篇
  1987年   1篇
  1985年   1篇
排序方式: 共有87条查询结果,搜索用时 78 毫秒
11.
A 3.5-year-old Yorkshire Terrier was evaluated for anorexia and vomiting; infection with Mycobacterium tuberculosis was diagnosed by use of histology, bacteriologic culture, and polymerase chain reaction (PCR) assay on various tissues. The dog was living with a human with an established M. tuberculosis infection. Findings were unique in that diagnosis of M. tuberculosis infection was obtained via PCR techniques, and isolates from the owner and dog were matched via restriction fragment length polymorphism fingerprinting. Dogs infected with M. tuberculosis from humans are most commonly infected via the respiratory tract. Clinical signs in dogs are variable and depend on the integrity of the immune system and the degree of dissemination. Diagnosis can often be obtained through histopathology and bacteriologic culture; additional diagnostic techniques are also available. Treatment of a dog with confirmed M. tuberculosis infection is controversial, and at least 6 months of multidrug treatment is required.  相似文献   
12.
The objective of this study was to determine the effect of season on the histologic and histomorphometric appearance of the normal equine pituitary gland. Pituitary glands were collected at necropsy from 121 horses throughout the year. Plasma was also collected from 59 of these horses before euthanasia. Hematoxylin and eosin stained median sagittal sections of each pituitary were evaluated and histologically graded by three pathologists. Histomorphometric analysis was performed on the same slides. Plasma α-melanocyte stimulating hormone was measured by radioimmunoassay in a subset of horses (n = 59). A total of 118 pituitary glands were included in the study after exclusions were made on the basis of the presence of pars intermedia (PI) adenomas (>5 mm). There was a positive correlation between PI hormone concentration (α-melanocyte stimulating hormone) and PI area. Pituitary gland measurements and grades from samples collected in the fall were compared with those collected in the nonfall months using t-test. The PI area, total pituitary area, and PI/total pituitary ratio were significantly greater in the fall compared with nonfall months (P < .0001, P < .01, P < .0001, respectively). Pituitary grades were also higher in the fall compared with nonfall months (P < .001). There was no seasonal difference in pars distalis or pars nervosa area. The results of this study show that the normal equine pituitary shows seasonal changes in appearance and size. These changes must be considered when using postmortem histologic evaluations in the diagnosis of pituitary pars intermedia dysfunction or for validation of antemortem diagnostic tests.  相似文献   
13.
This study describes the identification of a quantitative trait locus (QTL) in the recombinant inbred line population of ILL2024 × ILL6788 and subsequent validation of associated molecular markers. A high‐quality genetic linkage map was constructed with 758 markers that cover 1,057 cM, with an average intermarker distance of 2 cM. QTL analysis revealed a single genomic region on Lc2 to be associated with B tolerance and accounted for up to 76% of phenotypic variation (Vp). The best markers for B tolerance were assessed for their utility in routine breeding applications using validation panels of diverse lentil germplasm and breeding material derived from ILL2024. A marker generated from the dense genetic map of this study was found to be the most accurate of all markers available for B tolerance in lentil, with a success rate of 93% within a large breeding pool derived from ILL2024. However, given the number of the unrelated lines for which the marker–trait association was not conserved, B tolerance screening is still required at later stages to confirm predicted phenotypes.  相似文献   
14.
The optimum culture conditions of the local strain Chaetoceros calcitrans were determined to improve biomass and reduce cost of production. Under outdoor culture conditions, higher cell density was attained when the cultures were enriched with Tungkang Marine Research Laboratory (TMRL) medium composed of cheap technical grade reagents and cultured at 25 g L?1 salinity. The cultures were lighted with two 40 W cool-white GE fluorescent tubes (24–35 μmol photon m?2 s?1). Using semi-continuous culture system under established optimum culture conditions, C. calcitrans can be re-cultured thrice and concentrated at each culture cycle using electrolytic flocculation method to produce 4.6 kg m?3 of diatom paste. The viability of concentrated C. calcitrans after 3 months of storage was comparable to live diatom cells. Simple preservation technique by low-temperature storage is convenient for storing algal concentrates for use as starter cultures and for feeding invertebrates. The paste costs USD 8.24 kg?1 inclusive of the assets and flocculation materials for culturing and harvesting the diatom, respectively. This study established the suitable conditions for mass culture of C. calcitrans and produced concentrated diatoms in paste form that is readily available for aquaculture hatcheries at a lower cost.  相似文献   
15.
The objective of this study was to describe the histopathologic changes observed in extrapituitary organs as well as the pituitary glands of horses with pituitary pars intermedia dysfunction (PPID). Adrenal gland, thyroid gland, liver, lung, kidney, heart, and pituitary gland from 32 horses with clinical and histologic evidence of PPID and 20 control horses were reviewed histologically. Ten of the control horses were aged animals (≥15 years), allowing those changes attributed to age to be identified. In addition to previously reported changes in adrenal gland and liver, an association was established between PPID and several extrapituitary histopathologic changes, namely bronchiolitis, proliferative glomerulopathy, and myocardial lipofuscinosis and fibrosis. The potential biologic significance of these changes is discussed and, although the retrospective design of the current study precludes establishment of causal relationships between the observed extrapituitary changes and PPID, these findings suggest that further investigations are warranted.  相似文献   
16.
This retrospective study describes the use of and complications associated with parenteral nutrition (PN) administration to 53 equine neonates at the University of California Veterinary Medical Teaching Hospital. Medical records were examined and information obtained on signalment, physical examination, clinical diagnosis, outcome, total hospitalization time, insulin administration, microbiology culture results, other complications (i.e. thrombophlebitis) and necropsy findings. Complete blood count and serum biochemistry analytes, venous blood gas, serum electrolyte and glucose concentrations, and blood lactate concentration results were compared before and during PN administration in all foals. Seventeen foals (32%) developed hypertriglyceridemia (>200mg/dL). Triglyceride concentrations >200mg/dL were significantly (P=0.049) associated with non-survival. Forty-seven foals (89%) developed hyperglycemia (blood glucose >120mg/dL) and eight (15%) developed catheter-related complications (thrombosis or local sepsis). Packed cell volume, total protein, creatinine, blood urea nitrogen, and sorbitol dehydrogenase concentrations decreased while foals were on PN, while serum chloride concentration increased. This study highlighted that hypertriglyceridemia during the acute phase of neonatal illness may be detrimental to outcome, and that the safety of lipid-containing solutions in foals warrants further study.  相似文献   
17.
18.
19.
Duvaucel geckos (Hoplodactylus duvaucelii) are large endemic lizards that have been extirpated from the New Zealand mainland due to introduced mammalian predators. This species has subsequently become the subject of species translocation conservation management in an endeavour to increase the number of populations and as a part of island ecological restoration. Blood sampling of a captive adult male after tail autotomy led to the discovery of a Rickettsia-like organism within this gecko's erythrocytes. We conclude that this infection was acquired at the gecko's source location, a remote island closed to the general public and lacking potential invasive parasite reservoir reptiles. The likely vector is the native mite Geckobia naultina. This finding represents valuable new baseline information about the health parameters of this threatened species. Particularly in the light of the paucity of reported blood parasitism in New Zealand reptiles, the conservation management of this species through relocation and captive-breeding, and the on-going concerns regarding the introduction of novel parasites to New Zealand.  相似文献   
20.

Objective

To elucidate the structure of terminal inverted duplications and to investigate potential mechanisms of formation in two cases where there was mosaicism with cells of apparently normal karyotype.

Results

A karyotype [46,XY,inv dup(4)(p16.3p15.1)/46,XY] performed on blood lymphocytes from a patient referred for developmental delay (case 1) demonstrated a normal karyotype in 60% of cells with a terminal inverted duplication 4p in the remainder. In case 2, referred for multiple fetal anomalies on an ultrasound scan, 33% of amniocyte colonies were karyotypically normal, with a terminal inv dup 10p in the remainder [46,XX,inv dup(10)(p15.3p11)/46,XX]. Duplicated FISH signals for GATA3 and NEBL loci (in case 2), and for the Wolf-Hirschhorn locus (case 1) confirmed the inverted structure of both duplications. In the GTL banded normal cells from both cases, there was a cryptic deletion detected by FISH of one copy of the subtelomere 4p (case 1, probe GS-36P21), and subtelomere 10p (case 2, probe GS-306F7). At pter on both inv dup chromosomes there was no FISH signal present for the specific subtelomere probe. However, a positive pantelomeric probe signal was detected at 4 pter and 10 pter in both the cryptically-deleted chromosomes and the inv dup chromosomes in the respective cell lines of both cases.

Conclusion

An inv dup structure was evident for both cases on GTL bands, and confirmed by the various FISH studies. The presence of telomere (TTAGGG repeat) sequences at pter on the inv dup chromosomes (where more proximal chromosome specific subtelomeric probes were negative) was indicated by the pantelomeric probe signals in both cases. We conclude the most likely mechanism of origin in both cases was by sub-telomeric breakage in the zygote at pter, and delayed repair/rearrangement until after one or more subsequent mitotic divisions. In these divisions, at least one breakage-fusion-bridge cycle occurred, to produce inverted duplications. It is proposed then that two differently "repaired" daughter cells proliferated in parallel. In one daughter cell line (with an overtly normal karyotype) there was deletion of the subtelomere and presumed repair through capping by a neo-telomere (i.e. "healing", as initially proposed by McClintock). This occurred in both cases presented. In the other daughter cell of each case, it is proposed that chromosome stabilization was achieved (after replication) by sister chromatid reunion to form a dicentric, which broke at a subsequent anaphase, to form an inverted duplication (with loss of the reciprocal product, and the other daughter cell line). One inv dup was repaired without an interstitial specific subtelomere (case 1) and one was repaired with a duplicated specific interstitial subtelomere (case 2). After repair TTAGGG repeats were detected by FISH at each respective new pter.
  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