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   176篇
  免费   7篇
林业   2篇
农学   11篇
  17篇
综合类   5篇
农作物   5篇
水产渔业   19篇
畜牧兽医   94篇
园艺   1篇
植物保护   29篇
  2022年   3篇
  2021年   7篇
  2020年   1篇
  2018年   6篇
  2017年   3篇
  2016年   4篇
  2015年   13篇
  2014年   7篇
  2013年   7篇
  2012年   14篇
  2011年   7篇
  2010年   7篇
  2009年   3篇
  2008年   11篇
  2007年   7篇
  2006年   11篇
  2005年   10篇
  2004年   8篇
  2003年   6篇
  2002年   7篇
  2001年   7篇
  2000年   5篇
  1999年   5篇
  1994年   2篇
  1992年   2篇
  1990年   3篇
  1989年   2篇
  1988年   4篇
  1987年   1篇
  1986年   3篇
  1985年   1篇
  1982年   1篇
  1979年   2篇
  1976年   1篇
  1973年   1篇
  1971年   1篇
排序方式: 共有183条查询结果,搜索用时 15 毫秒
81.
The c-Met proto-oncogene is the receptor for hepatocyte growth factor (HGF), which is a member of the tyrosine kinase family. Activation of the HGF/c-Met signal pathway leads to cell proliferation, motility, regeneration, and morphogenesis. In this study, the complete nucleotide sequence of complementary DNA (cDNA) of canine c-Met was cloned, and its distribution was determined in tissues. The canine c-Met cDNA clone had an open reading frame of 4419 bp that encoded a putative polypeptide of 1383 amino acids. The c-Met mRNA was expressed in a variety of canine tissues including peripheral blood mononuclear cells (PBMC), bone marrow, liver, kidney, lung, stomach, uterus, testis, thymus, lymph node, small intestine, colon, adrenal gland, thyroid gland, heart, muscle, skin, pancreas, ovary, prostate, spleen, fat, cerebrum, and cerebellum. In addition, the c-Met mRNA expression in normal and regenerated liver was examined. The levels of the mRNA increased 2-fold in regenerated liver compared to that found in normal liver, indicating that c-Met is involved in various functions including remodeling of canine hepatocytes.  相似文献   
82.
Cutaneous mastocytosis, which resembles a subset of urticaria pigmentosa in humans, is rare in dogs. We herein report unrepresentative neoplastic proliferation of mast cells in ventral skin removed routinely from a nine-month-old female laboratory beagle dog at necropsy. A histological examination revealed diffuse extensive cellular infiltration from the superficial to deep dermis in most parts of the skin around the fourth and fifth mammary papilla without nodule formation. Tumor cells were fairly monomorphic, well-differentiated mast cells with round nuclei of small distinct nucleoli and moderate to abundant, slightly eosinophilic and granular cytoplasm. A perivascular arrangement of mast cells was noted at the margin of the lesions. Infiltration of eosinophils and degeneration of collagen were not observed in the dermis. Cutaneous mastocytosis was diagnosed based on these features. A sequence analysis of lesions revealed the deletion of Gln555 to Ile570 within the juxtamembrane domain of c-kit (exon 11).  相似文献   
83.
The present study assessed the effects of intramammary infusion of Bifidobacterium breve (B. breve) on mastitis‐causing pathogens and on the somatic cell counts (SCC) in lactating cows with chronic subclinical mastitis. The bacteriological cure rates of 42 quarters from 42 cows infected with Staphylococcus aureus, Corynebacterium bovis, coagulase‐negative staphylococci, and environmental streptococci were 18.2% (2/11), 14.3% (1/7), 58.8% (10/17), and 28.6% (2/7), respectively, on day 14 after B. breve infusion. In a second trial, B. breve was infused into 18 quarters from 18 cows with chronic subclinical mastitis from which pathogens had not been isolated; the rates of quarters showing SCC > 50 × 104 cells/ml prior to B. breve infusion that decreased to < 30 × 104 cells/ml after infusion were significantly (p < .01) increased to 61.1% (11/18) on day 14 compared to that prior to infusion (0/18). The intramammary infusion of B. breve appears to be a non‐antibiotic approach for elimination of minor pathogens and decreasing SCC in quarters with chronic subclinical mastitis in dairy cows.  相似文献   
84.
Journal of General Plant Pathology - An easy, rapid method has been needed to test the pathogenicity of strains of Ralstonia pseudosolanacearum, the cause of serious bacterial wilt on ginger...  相似文献   
85.
Expression of calbindin-D28K in sporadic nephroblastomas of the chicken   总被引:2,自引:0,他引:2  
Calbindin-D28K (Ca-D28K) is a calcium-binding protein. In the kidney, Ca-D28K is present in the distal nephron, but not in the proximal nephron. This site-specific distribution in the kidney indicates that Ca-D28K is a potential marker for the differentiation of the distal nephron. In this study, we have examined the expression of Ca-D28K in 25 sporadic cases of chicken nephroblastomas. All cases of nephroblastomas were composed of atypical tubular structures, blastemal cells, and fibrous stroma in varying degrees of differentiation. Immunohistochemically in all nephroblastoma specimens, Ca-D28K was expressed in the epithelial cells of the subsets of tubular structures, but not in the blastema or the stroma. These results suggested that the tubuli in the nephroblastomas are able to differentiate into the phenotype of distal nephrons. Furthermore, Ca-D28K might develop as a novel diagnostic marker for nephroblastomas because this molecule is reported to be completely negative in other renal tumors, including renal cell carcinoma, chromophobe carcinomas, and oncocytoma.  相似文献   
86.
Fenny Dane  T. Tsuchiya 《Euphytica》1976,25(1):367-374
Summary Cytological investigations of 50 wild Cucumis introductions revealed the presence of three tetraploid species with 2n=48 chromosomes, and one hexaploid species with 2n=72 chromosomes, while all other species are diploid containing 2ns=14 or 2n=24 chromosomes. Two of the tetraploid species, C. heptadactylus (P.I. 282446), and a species related to C. zeyheri (P.I. 273192, 299570, 299571, and 299572) are natives of South Africa, while C. aculeatus (P.I. 193967, 196844, 273648, 273649, and 273650) is found in Ethiopia. The hexaploid, C. figarei (P.I. 343699, 343700, 343701), is a native of Nigeria. All polyploids are perennial, have efficient vegetative reproduction systems, and may have originated from the spontaneous formation of polysomatic cells.Supported by the Colorado State University Experiment Station and published as Scientific Series Paper No. 2089.  相似文献   
87.
88.
Iron overload has been well recognized to cause oxidant-mediated cellular/tissue injury; however, little is known about the effects of iron overload on the blood coagulation system. We encountered an unexpected bleeding tendency in rats fed a high-iron diet in a set of studies using iron-modified diets. In this study, we investigated the mechanism of hemorrhagic diathesis induced by dietary iron overload in rats. Six-week-old F344/DuCrlCrlj male rats were fed a standard (containing 0.02% iron) or a high-iron diet (containing 1% iron) for 6 weeks and were then sampled for hematological, blood biochemical, coagulation, and pathological examinations. Serum and liver iron levels increased in rats fed the high-iron diet (Fe group) and serum transferrin was almost saturated with iron. However, serum transaminase levels did not increase. Moreover, plasma prothrombin time and activated partial thromboplastin time were significantly prolonged, regardless of the presence of hemorrhage. The activity of clotting factors II and VII (vitamin K-dependent coagulation factors) decreased significantly, whereas that of factor VIII was unaltered. Blood platelet levels were not influenced by dietary iron overload, suggesting that the bleeding tendency in iron-overloaded rats is caused by secondary hemostasis impairment. In addition, hemorrhage was observed in multiple organs in rats fed diets containing more than 0.8% iron. Our results suggest that iron overload can increase the susceptibility of coagulation abnormalities caused by latent vitamin K insufficiency.  相似文献   
89.
The live microbiota ecosystem in the intestine plays a critical role in maintaining the normal physiological and psychological functions in both animals and human beings. However, the chronic effect of microbiota disturbances during prenatal and neonatal developing periods on animal's health remains less studied. In the current study, pregnant ICR mice were fed with an antibiotic diet (7-g nebacitin [bacitracin-neomycin sulphate 2:1]/kg standard diet) from day 14 of conception, and their offspring were provided with the same diet till the termination of the experiments. Dams treated with antibiotics showed increased body weight along with enlarged gut. Antibiotic-treated offspring revealed decreased bodyweight, increased food, water, and sucrose intake. Administration of antibiotics affected corticosterone responsivity to acute 20 min restraint challenge in male pups. In behavior tests, female pups showed decreased movement in open field while male pups revealed decreased latency to open arms in elevated plus maze test and immobility time in tail suspension test. Together, these results suggested that early antibiotic exposure may impact on the food intake, body weight gain, and emotional behavior regulation in mice.  相似文献   
90.
Many studies have shown the ecological importance of viruses as the greatest genomic reservoirs on the planet. As bacteriophages (phages) comprise the majority of viruses in the environment, we surveyed the capsid genes (g23) of T4-type phages, Myoviridae, from DNA extracts of three paddy field soils located in northern, central and southern Japan using the degenerate primers MZIA1bis and MZIA6. Denaturing gradient gel electrophoresis (DGGE) was performed to separate PCR-amplified g23 products, and 56 DGGE bands were identified as g23 fragments. Only nine clones were grouped into T-evens, PseudoT-evens and ExoT-evens, and most of the other clones were classified into Paddy Groups I-VI. No significantly different distribution of g23 clones was observed among the paddy fields at the group level, indicating that phage communities estimated from the g23 composition were common on the nationwide level. Comparison of g23 sequences showed that g23 genes in paddy fields were different from those in marine environments, and more divergence of g23 genes was estimated in the paddy fields compared to the marine environment. Two novel g23 clones with very short amino acid residues were detected, suggesting the existence of uncharacterized, novel groups of g23 genes in paddy field soils.  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