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   86篇
  免费   6篇
  国内免费   2篇
林业   3篇
农学   3篇
  12篇
综合类   2篇
农作物   18篇
水产渔业   4篇
畜牧兽医   43篇
植物保护   9篇
  2022年   7篇
  2021年   4篇
  2020年   4篇
  2019年   2篇
  2018年   3篇
  2017年   4篇
  2016年   6篇
  2015年   6篇
  2014年   4篇
  2013年   4篇
  2012年   4篇
  2011年   4篇
  2010年   6篇
  2009年   3篇
  2008年   8篇
  2007年   2篇
  2006年   5篇
  2005年   7篇
  2004年   3篇
  2003年   3篇
  2002年   1篇
  1997年   1篇
  1996年   2篇
  1933年   1篇
排序方式: 共有94条查询结果,搜索用时 31 毫秒
31.
Microglia are evenly distributed throughout the brain parenchyma. They respond rapidly to a variety of alterations in the microenvironment of the brain and act as sensors for pathological events in the brain. In the present study, we investigated the age-dependent changes in the immunoreactivity and protein level of ionized calcium-binding adapter molecule 1 (Iba-1), a microglial marker, in the CA1 region of the gerbil hippocampus. Iba-1 immunoreactive microglia were detected in the hippocampal CA1 region of the postnatal month 1 (PM 1) group. Iba-1 positive microglia were morphologically inactive between the PM 1 and PM 12 stages. Some Iba-1 immunoreactive microglia were present in the active form in the hippocampal CA1 region of the PM 18 and PM 24 groups. The Iba-1 protein levels in hippocampal CA1 homogenates were decreased in the PM 1 through PM 6 groups and increased in an age-dependent manner thereafter. These results suggest that Iba-1 immunoreactive microglia in the active form were detected in the hippocampal CA1 region in the PM 18 and PM 24 groups. This result may be associated with an age-dependent susceptibility to neurodegenerative diseases associated with the hippocampus.  相似文献   
32.
Gliotoxin, a secondary metabolite produced by marine fungus Aspergillus sp., possesses various biological activities including anticancer activity. However, the mechanism underlying gliotoxin-induced cytotoxicity on human cervical cancer (Hela) and human chondrosarcoma (SW1353) cells remains unclear. In this study, we focused on the effect of gliotoxin induction on apoptosis, the activating expressions of caspase family enzymes in the cells. Apoptotic cell levels were measured through DAPI and Annexin V/Propidium Iodide (PI) double staining analysis. The apoptotic protein expression of Bcl-2 and caspase family was detected by Western blot in Hela and SW1353 cells. Our results showed that gliotoxin treatment inhibited cell proliferation and induced significant morphological changes. Gliotoxin induced apoptosis was further confirmed by DNA fragmentation, chromatin condensation and disrupted mitochondrial membrane potential. Gliotoxin-induced activation of caspase-3, caspase-8 and caspase-9, down-regulation of Bcl-2, up-regulation of Bax and cytochromec (cyt c) release showed evidence for the gliotoxin activity on apoptosis. These findings suggest that gliotoxin isolated from marine fungus Aspergillus sp. induced apoptosis in Hela and SW1353 cells via the mitochondrial pathway followed by downstream events leading to apoptotic mode of cell death.  相似文献   
33.
An immunochromatography (ICG) strip test for rapid detection of atrazine in water samples was developed. A monoclonal antibody (MAb) specific to atrazine was produced from the cloned hybridoma cell (AT-1-M3) and used to develop a direct competitive enzyme-linked immunosorbent assay (DC-ELISA) and ICG strip. MAb conjugated to colloidal gold, and that was applied to the conjugate pad of the ICG strip. The visual detection limit for the ICG strip was 3 ng/mL. This test required only 10 min to get results and one step of sample to perform the assay. The results of water samples spiked with 5, 10, 20, and 50 ng/mL of atrazine by ICG strip were in good agreement with those obtained by DC-ELISA. The ICG strip was sufficiently sensitive and accurate to be useful for rapid screening of atrazine in various water samples.  相似文献   
34.
Ribavirin (RBV) is a synthetic guanosine analog that is used as a drug against various viral diseases in humans. The in vitro antiviral effects of ribavirin against porcine viruses were demonstrated in several studies. The purposes of this study were to evaluate the adverse effects and pharmacokinetics of ribavirin following its intramuscular (IM) injection in pigs. Ribavirin was formulated as a double‐oil emulsion (RBV‐DOE) and gel (RBV‐Gel), which were injected into the pigs as single‐dose IM injections. After injection of RBV, all of the pigs were monitored. The collected serum and whole blood samples were analyzed by liquid chromatography–tandem mass spectrometry and complete blood count analysis, respectively. All of the ribavirin‐treated pigs showed significant decreases in body weight compared to the control groups. Severe clinical signs including dyspnea, anorexia, weakness, and depression were present in ribavirin‐treated pigs until 5 days postinjection (dpi). The ribavirin‐treated groups showed significant decrease in the number of red blood cells and hemoglobin concentration until 8 dpi. The mean half‐life of the RBV‐DOE and RBV‐Gel was 27.949 ± 2.783 h and 37.374 ± 3.502 h, respectively. The mean peak serum concentration (Cmax) and area under the serum concentration–time curve from time zero to infinity (AUCinf) of RBV‐DOE were 8340.000 ± 2562.577 ng/mL and 16 0095.430 ± 61 253.400 h·ng/mL, respectively. The Cmax and AUCinf of RBV‐Gel were 15 300.000 ± 3764.306 ng/mL and 207526.260 ± 63656.390 h·ng/mL, respectively. The results of this study provided the index of side effect and pharmacokinetics of ribavirin in pigs, which should be considered before clinical application.  相似文献   
35.
Aluminum (Al) accumulation increases with aging, and long-term exposure to Al is regarded as a risk factor for Alzheimer''s disease. In this study, we investigated the effects of Al and/or D-galactose on neural stem cells, proliferating cells, differentiating neuroblasts, and mature neurons in the hippocampal dentate gyrus. AlCl3 (40 mg/kg/day) was intraperitoneally administered to C57BL/6J mice for 4 weeks. In addition, vehicle (physiological saline) or D-galactose (100 mg/kg) was subcutaneously injected to these mice immediately after AlCl3 treatment. Neural stem cells, proliferating cells, differentiating neuroblasts, and mature neurons were detected using the relevant marker for each cell type, including nestin, Ki67, doublecortin, and NeuN, respectively, via immunohistochemistry. Subchronic (4 weeks) exposure to Al in mice reduced neural stem cells, proliferating cells, and differentiating neuroblasts without causing any changes to mature neurons. This Al-induced reduction effect was exacerbated in D-galactose-treated mice compared to vehicle-treated adult mice. Moreover, exposure to Al enhanced lipid peroxidation in the hippocampus and expression of antioxidants such as Cu, Zn- and Mn-superoxide dismutase in D-galactose-treated mice. These results suggest that Al accelerates the reduction of neural stem cells, proliferating cells, and differentiating neuroblasts in D-galactose-treated mice via oxidative stress, without inducing loss in mature neurons.  相似文献   
36.
Background: Previously, we showed that targeted disruption of viral receptor genes in avian leukosis virus(ALV)subgroups using clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated protein 9(Cas9))-based genome editing confers resistance to ALV subgroups B and J. Here, we used the same strategy to target the receptor expressed by ALV subgroup A(TVA) and generate chicken cells resistant to infection by this virus.Results: CRISPR/Cas9-based disruption of exon 2 within the tva gene of DF-1 fibroblasts conferred resistance to infection by ALV subgroup A regardless of whether frameshift mutations were introduced during editing. Conversely,overexpression of the wild-type TVA receptor(wtTVA) by tva-modified DF-1 clones restored susceptibility to ALV subgroup A. The results confirm that exon 2, which contains the low-density lipoprotein receptor class A domain of TVA, is critical for virus entry. Furthermore, we sequentially modified DF-1 cells by editing the tva, tvb, and Na~+/H~+ exchange 1(chNHE1) genes, which are the specific receptors for ALV subgroups A, B, and J, respectively.Conclusions: Simultaneous editing of multiple receptors to block infection by different subgroups of ALV confirmed that ALV subgroups A, B, and J do not share host receptors. This strategy could be used to generate cells resistant to multiple viral pathogens that use distinct receptors for cell entry.  相似文献   
37.
The medfly (Ceratitis capitata) is one of the major agricultural pests controlled through sterile insect technique (SIT) programs. We studied the chemical composition of the volatiles released by calling males from one laboratory and two wild C. capitata populations using two-dimensional gas chromatography with time-of-flight mass spectrometric detection (GC × GC/TOFMS) and gas chromatography with electroantennographic detection (GC-EAD). Multivariate data analyses revealed significant differences in the quantitative and qualitative composition of male chemical emanations between the three populations. The GC-EAD analyses of the male emanation of three C. capitata populations revealed 14 antenally active compounds. The volatiles isomenthone, β-pinene, ethyl octanoate, indole, geraniol, bornyl acetate, geranyl acetone, and (E)-caryophyllene are newly reported EAD active constituents of the male pheromone. GC-EAD analyses of the laboratory population indicated that the males and females of C. capitata possess comparable sensitivity to male-produced volatiles. Our results are relevant to the development of a pheromone-based monitoring system and also to the SIT control program.  相似文献   
38.
39.
Objective  To evaluate motility of silicone orbital implants and corneoscleral prostheses, with and without use of a motility coupling post (MCP) in dogs.
Animals studied  Eighteen mixed-breed dogs.
Procedures  The motility of an orbital silicone implant and corneoscleral prosthesis after enucleation ( n  = 6), evisceration ( n  = 6), or use of a MCP with evisceration ( n  = 6) in dogs were compared. One eye from each dog had surgery whereas the opposite eye was used as a control. Clinical evaluations were performed three times a week. Histopathology of the orbital tissues was performed 8 and 12 weeks after surgery.
Results  Implant motility in dogs with evisceration (vertical movement [VM] 8.04 ± 2.13; horizontal movement [HM] 11 ± 3.05) and evisceration with MCP (VM 9.61 ± 1.59); HM was significantly greater than the enucleation group (VM 0.51 ± 0.5; HM 1.22 ± 0.68) ( P <  0.01). Prosthetic motility in dogs with evisceration with MCP was significantly greater than in dogs with evisceration; dogs with evisceration had significantly greater motility than dogs with enucleation ( P <  0.01). No postoperative complications were observed in any of the groups. No significant abnormalities were noted on histopathology.
Conclusions  MCP placement in silicone orbital implants significantly enhanced the prosthetic motility in dogs. This study supports the use of MCP in silicone orbital implants to enhance corneoscleral prosthesis motility and cosmetics in dogs.  相似文献   
40.
Objective  To determine the incidence, etiology, and concurrent ophthalmic findings in small breed dogs that presented with cataracts.
Animal studied  Five hundred and sixty-one small breed dogs (942 eyes) were presented to the Veterinary Medical Teaching Hospital of Seoul National University between July 2002 and December 2007 with cataract.
Procedure  The medical records of small breed dogs with cataract were reviewed. The reason for presentation, cataract duration, bilaterality, breed, gender, age, vision, etiology, stage of cataract development, concurrent ophthalmic findings, IOP, ocular ultrasonography findings, and scotopic electroretinography (ERG) findings were investigated.
Results  The most frequently presented breeds were the Miniature/Toy Poodle ( n  = 112, 20.0%), Yorkshire Terrier ( n  = 110, 19.6%), and Shih Tzu ( n  = 95, 16.9%). The Miniature/Toy Poodle showed a significantly higher odds ratio for cataract formation (2.6). The proportion of female cataract patients was significantly higher than that of male cataract patients in the overall population ( P  < 0.05). The Miniature/Toy Poodles had significantly higher numbers of females affected with cataract ( P  < 0.01). The mean age for cataract formation was 8.3 ± 3.9 years. The mean age at onset in the Miniature/Toy Poodle and Yorkshire Terrier was significantly higher, whereas that in the Miniature Schnauzer group was significantly lower ( P  < 0.0001). Clinical signs related to lens induced uveitis had a tendency to increase with cataract progression ( P  < 0.05). There were no significant differences in the b-wave amplitude for mixed rod cone response by stage ( P  = 0.137).
Conclusions  Small breed dogs with cataracts had characteristics with regard to age of onset and gender distribution, depending on the breed.  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