全文获取类型
收费全文 | 1860篇 |
免费 | 214篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 12篇 |
儿科学 | 57篇 |
妇产科学 | 67篇 |
基础医学 | 200篇 |
口腔科学 | 46篇 |
临床医学 | 209篇 |
内科学 | 370篇 |
皮肤病学 | 26篇 |
神经病学 | 213篇 |
特种医学 | 202篇 |
外科学 | 250篇 |
综合类 | 47篇 |
预防医学 | 192篇 |
眼科学 | 26篇 |
药学 | 98篇 |
2篇 | |
中国医学 | 2篇 |
肿瘤学 | 66篇 |
出版年
2021年 | 23篇 |
2020年 | 14篇 |
2019年 | 25篇 |
2018年 | 26篇 |
2017年 | 26篇 |
2016年 | 19篇 |
2015年 | 27篇 |
2014年 | 44篇 |
2013年 | 53篇 |
2012年 | 68篇 |
2011年 | 62篇 |
2010年 | 47篇 |
2009年 | 53篇 |
2008年 | 60篇 |
2007年 | 74篇 |
2006年 | 75篇 |
2005年 | 63篇 |
2004年 | 60篇 |
2003年 | 65篇 |
2002年 | 65篇 |
2001年 | 62篇 |
2000年 | 64篇 |
1999年 | 43篇 |
1998年 | 43篇 |
1997年 | 40篇 |
1996年 | 33篇 |
1995年 | 26篇 |
1994年 | 30篇 |
1993年 | 24篇 |
1992年 | 50篇 |
1991年 | 39篇 |
1990年 | 40篇 |
1989年 | 56篇 |
1988年 | 46篇 |
1987年 | 55篇 |
1986年 | 46篇 |
1985年 | 58篇 |
1984年 | 37篇 |
1983年 | 30篇 |
1982年 | 21篇 |
1981年 | 21篇 |
1980年 | 19篇 |
1979年 | 31篇 |
1978年 | 20篇 |
1977年 | 14篇 |
1976年 | 25篇 |
1975年 | 27篇 |
1974年 | 21篇 |
1973年 | 18篇 |
1971年 | 16篇 |
排序方式: 共有2085条查询结果,搜索用时 15 毫秒
11.
12.
Intestinal schistosomiasis japonica: CT-pathologic correlation 总被引:1,自引:0,他引:1
Lee RC; Chiang JH; Chou YH; Rubesin SE; Wu HP; Jeng WC; Hsu CC; Tiu CM; Chang T 《Radiology》1994,193(2):539
13.
14.
15.
16.
17.
S A Holland L C Hutton F N McKenzie 《Journal l'Association canadienne des radiologistes》1989,40(2):94-97
The chest radiographic findings and pulmonary radionuclide studies of four patients who underwent heart-lung transplantation between May 1983 and June 1986 were reviewed retrospectively. The two long-term survivors both developed bronchiolitis obliterans (presenting at 32 months postoperatively in the first patient and 14.5 months postoperatively in the second). The etiology of this is likely to be multifactorial and includes pulmonary rejection which may develop without concomitant cardiac rejection. The radiologist must be alert to this complication in heart-lung transplantation. The chest radiographs in our two patients showed diminution of peripheral bronchovascular markings and overinflation. The importance of careful screening of the radiographs of potential donors to detect pneumonia is emphasized. In one patient, a unilateral pneumothorax spread contralaterally due to the absence of normal anatomic barriers. The "reimplantation response" was not a prominent feature and was seen in one patient only. This response has been observed in heart-lung transplant recipients during the second postoperative week. The radiologic appearance is that of interstitial edema not explained by any clinical or hemodynamic findings. 相似文献
18.
Duncan WC; Illingworth PJ; Young FM; Fraser HM 《Human reproduction (Oxford, England)》1998,13(9):2532-2540
The molecular mechanisms involved in luteolysis are still unclear in the
primate. This study aimed to investigate the effect of induced luteolysis
on the ovarian luteinizing hormone (LH) receptor and the steroidogenic
enzyme, 3beta-hydroxysteroid dehydrogenase (3beta-HSD) in the marmoset
monkey. Luteolysis was induced in the mid-luteal phase either directly by
systemic prostaglandin F2alpha (PGF2alpha), or indirectly by LH withdrawal
using systemic gonadotrophin releasing hormone antagonist (GnRHant)
treatment. The LH receptor was studied by isotopic mRNA in-situ
hybridization and in-situ ligand binding and 3beta-HSD expression was
studied using isotopic mRNA in-situ hybridization and immunohistochemistry.
Induced luteolysis was associated with a reduction in the expression of LH
receptor (P < 0.0001) and 3beta-HSD mRNA, closely followed by a
reduction in the LH receptor (P < 0.05) and 3beta-HSD protein
concentrations within 24 h. There were no differences in the findings
whether luteolysis was induced with PGF2alpha or GnRHant. This study shows
that disparate mechanisms to induce luteolysis in the primate result in an
identical rapid loss of the LH receptor and 3beta-HSD. In conclusion,
induced luteolysis leads to rapid loss of the steroidogenic pathway in
luteal cells.
相似文献
19.
Detection of Serum Antibodies to Ovine Progressive Pneumonia Virus in Sheep by Using a Caprine Arthritis-Encephalitis Virus Competitive-Inhibition Enzyme-Linked Immunosorbent Assay
下载免费PDF全文
![点击此处可从《Clinical and Vaccine Immunology : CVI》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Lynn M. Herrmann William P. Cheevers Katherine L. Marshall Travis C. McGuire Melinda M. Hutton Gregory S. Lewis Donald P. Knowles 《Clinical and Vaccine Immunology : CVI》2003,10(5):862-865
A competitive-inhibition enzyme-linked immunosorbent assay (cELISA) for detection of antibodies to the surface envelope (SU) of caprine arthritis-encephalitis virus (CAEV) was recently reported (L. M. Herrmann, W. P. Cheevers, T. C. McGuire, D. Scott Adams, M. M. Hutton, W. G. Gavin, and D. P. Knowles, Clin. Diagn. Lab. Immunol. 10:267-271, 2003). The cELISA utilizes CAEV-63 SU captured on microtiter plates using the monoclonal antibody (MAb) F7-299 and measures competitive displacement of binding of the anti-CAEV MAb GPB 74A by goat serum. The present study evaluated the CAEV cELISA for detection of antibodies to ovine progressive pneumonia virus (OPPV) in sheep. Three hundred thirty-two sera were randomly selected from 21,373 sheep sera collected throughout the United States to determine the sensitivity and specificity of cELISA and agar gel immunodiffusion (AGID) based on immunoprecipitation (IP) of [35S]methionine-labeled OPPV antigens as a standard of comparison. A positive cELISA test was defined as >20.9 percent inhibition (% I) of MAb 74A binding based on two standard deviations above the mean % I of 191 IP-negative sheep sera. At this cutoff, there were 2 of 141 false-negative sera (98.6% sensitivity) and 6 of 191 false-positive sera (96.9% specificity). Sensitivity and specificity values for IP-monitored AGID were comparable to those for cELISA for 314 of 332 sera with unambiguous AGID results. Concordant results by cELISA and IP resolved 16 of the 18 sera that were indeterminate by AGID. Additional studies evaluated cELISA by using 539 sera from a single OPPV-positive flock. Based on IP of 36 of these sera, there was one false-negative by cELISA among 21 IP-positive sera (95.5% sensitivity) and 0 of 15 false-positives (100% specificity). We conclude that the CAEV cELISA can be applied to detection of OPPV antibodies in sheep with high sensitivity and specificity. 相似文献
20.
Klein RL Lin WL Dickson DW Lewis J Hutton M Duff K Meyer EM King MA 《The American journal of pathology》2004,164(1):347-353
Neurofibrillary pathology was produced in the brains of adult rats after localized gene transfer of human tau carrying the P301L mutation, which is associated with frontotemporal dementia with parkinsonism. Within 1 month of in situ transfection of the basal forebrain region of normal rats, tau-immunoreactive and argyrophilic neuronal lesions formed. The fibrillar lesions had features of neurofibrillary tangles and tau immunoreactivity at light and electron microscopic levels. In addition to neurofibrillary tangles, other tau pathology, including pretangles and neuropil threads, was abundant and widespread. Tau gene transfer to the hippocampal region of amyloid-depositing transgenic mice produced pretangles and threads, as well as intensely tau-immunoreactive neurites in amyloid plaques. The ability to produce neurofibrillary pathology in adult rodents makes this a useful method to study tau-related neurodegeneration. 相似文献