全文获取类型
收费全文 | 9824篇 |
免费 | 946篇 |
国内免费 | 67篇 |
专业分类
耳鼻咽喉 | 65篇 |
儿科学 | 265篇 |
妇产科学 | 220篇 |
基础医学 | 1518篇 |
口腔科学 | 151篇 |
临床医学 | 1314篇 |
内科学 | 1905篇 |
皮肤病学 | 232篇 |
神经病学 | 617篇 |
特种医学 | 762篇 |
外科学 | 1176篇 |
综合类 | 152篇 |
一般理论 | 6篇 |
预防医学 | 922篇 |
眼科学 | 123篇 |
药学 | 601篇 |
中国医学 | 9篇 |
肿瘤学 | 799篇 |
出版年
2021年 | 127篇 |
2020年 | 85篇 |
2019年 | 153篇 |
2018年 | 158篇 |
2017年 | 119篇 |
2016年 | 119篇 |
2015年 | 141篇 |
2014年 | 201篇 |
2013年 | 330篇 |
2012年 | 431篇 |
2011年 | 450篇 |
2010年 | 275篇 |
2009年 | 297篇 |
2008年 | 424篇 |
2007年 | 463篇 |
2006年 | 422篇 |
2005年 | 424篇 |
2004年 | 403篇 |
2003年 | 376篇 |
2002年 | 326篇 |
2001年 | 274篇 |
2000年 | 303篇 |
1999年 | 280篇 |
1998年 | 165篇 |
1997年 | 183篇 |
1996年 | 186篇 |
1995年 | 142篇 |
1994年 | 139篇 |
1993年 | 122篇 |
1992年 | 228篇 |
1991年 | 237篇 |
1990年 | 197篇 |
1989年 | 203篇 |
1988年 | 204篇 |
1987年 | 172篇 |
1986年 | 200篇 |
1985年 | 180篇 |
1984年 | 117篇 |
1983年 | 104篇 |
1982年 | 79篇 |
1981年 | 81篇 |
1979年 | 88篇 |
1978年 | 98篇 |
1977年 | 87篇 |
1976年 | 90篇 |
1975年 | 84篇 |
1974年 | 94篇 |
1973年 | 82篇 |
1972年 | 68篇 |
1971年 | 66篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
Isolation of rhinoviruses and coronaviruses from 38 colds in adults 总被引:10,自引:0,他引:10
Nasal washings were collected from 27 normal adults during 38 naturally acquired colds. The washings were exhaustively tested using tissue cultures, organ cultures and electron microscopy. Washings yielding no identifiable agent were inoculated into human volunteers, and further specimens obtained from the latter were examined by the same techniques in vitro. Viruses were identified in association with 25 of the original 38 colds (65.7%). Fifteen were rhinoviruses (39.5%), seven coronaviruses (18.4%), two were para-influenza viruses, and one was influenza virus. Use of organ cultures and of volunteers significantly increased the isolation rate. No agent was cultivated from the remaining 13 specimens, although tests in volunteers showed that cold-producing agents were present in five of them (13%). Three specimens gave doubtful results in volunteers, and five others, all collected within a period of six weeks in December and January, apparently contained no infectious agent. 相似文献
52.
Virginia A Reed G Christian Jernstedt Mark Ballow Robert K Bush Anita T Gewurz Stephen J McGeady 《Academic medicine》2004,79(11):1062-1066
Graduate medical education programs face new challenges as they seek to comply with the mandate from the Accreditation Council on Graduate Medical Education to demonstrate that they are teaching and assessing residents on the six core competencies. The authors describe a project designed as a collaborative venture between the American Academy of Allergy, Asthma, and Immunology (AAAAI) and the Center for Educational Outcomes at Dartmouth College (CEdO) to provide residency programs in allergy/immunology with resources for teaching and assessing the core competencies. The goal was to create a set of learning and assessment resources that maximized the content knowledge expertise provided by the AAAAI and the learning expertise provided by CEdO. A highly interactive, iterative process was used to create a set of Web-based modules. Bilateral communication, buy-in, and active involvement in the process were seen as crucial to the development of resources and their successful implementation. Approximately 18 months after the modules were made available to training program directors, 80% of the directors surveyed were aware of and had accessed the modules. The joint creation process used in this project, designed to be generally applicable across specialties, reveals how the burden of meeting new requirements can be decreased when experts in content knowledge and experts in learning collaborate. 相似文献
53.
Antiphospholipid antibodies and the outcome of pregnancy after the first in-vitro fertilization and embryo transfer cycle 总被引:1,自引:1,他引:1
Balasch J; Creus M; Fabregues F; Civico S; Reverter JC; Carmona F; Tassies D; Vanrell JA 《Human reproduction (Oxford, England)》1998,13(5):1180-1183
Increased antiphospholipid antibody prevalence has been demonstrated by a
number of recent studies in in-vitro fertilization (IVF) patients but the
potential effects of antiphospholipid antibodies on the different
components of the reproductive process and the consideration of whether to
test IVF patients for antiphospholipid antibodies are controversial. The
present study was undertaken to investigate the possible association
between the presence of circulating antiphospholipid antibodies (namely the
lupus anticoagulant and anticardiolipin antibodies), among a series of 21
consecutive IVF patients having a clinical spontaneous abortion after their
first embryo transfer. As a control group (n=42), the nearest IVF cycle
resulting in an ongoing pregnancy before and after each miscarried IVF
cycle (i.e. the closest cycles in temporal relationship to the index cycle)
was used. One patient (4.8%) in the study group and two women (4.8%) among
controls were seropositive for antiphospholipid antibodies. These low and
similar seropositivity rates found in the two groups studied lead us to
conclude that antiphospholipid antibodies testing in IVF patients should be
considered only in those women having repeated failures of
implantation/clinical abortion after embryo transfer but not in an
infertile general population reaching an IVF programme.
相似文献
54.
Use of multiepitope polyproteins in serodiagnosis of active tuberculosis 总被引:13,自引:0,他引:13
Houghton RL Lodes MJ Dillon DC Reynolds LD Day CH McNeill PD Hendrickson RC Skeiky YA Sampaio DP Badaro R Lyashchenko KP Reed SG 《Clinical and diagnostic laboratory immunology》2002,9(4):883-891
Screening of genomic expression libraries from Mycobacterium tuberculosis with sera from tuberculosis (TB) patients or rabbit antiserum to M. tuberculosis led to the identification of novel antigens capable of detecting specific antibodies to M. tuberculosis. Three antigens, Mtb11 (also known as CFP-10), Mtb8, and Mtb48, were tested together with the previously reported 38-kDa protein, in an enzyme-linked immunosorbent assay (ELISA) to detect antibodies in TB patients. These four proteins were also produced as a genetically fused polyprotein, which was tested with two additional antigens, DPEP (also known as MPT32) and Mtb81. Sera from individuals with pulmonary and extrapulmonary TB, human immunodeficiency virus (HIV)-TB coinfections, and purified protein derivative (PPD)-positive and PPD-negative status with no evidence of disease were tested. In samples from HIV-negative individuals, the ELISA detected antibodies in >80% of smear-positive individuals and >60% smear-negative individuals, with a specificity of approximately 98%. For this group, smears detected 81.6% but a combination of smear and ELISA had a sensitivity of approximately 93%. The antigen combination detected a significant number of HIV-TB coinfections as well as antibodies in patients with extrapulmonary infections. Improved reactivity in the HIV-TB group was observed by including the antigen Mtb81 that was identified by proteomics. The data indicate that the use of multiple antigens, some of which are in a single polyprotein, can be used to facilitate the development of a highly sensitive test for M. tuberculosis antibody detection. 相似文献
55.
Shimizu S Krafchak C Fuse N Epstein MP Schteingart MT Sugar A Eibschitz-Tsimhoni M Downs CA Rozsa F Trager EH Reed DM Boehnke M Moroi SE Richards JE 《American journal of medical genetics. Part A》2004,(4):372-377
Posterior polymorphous corneal dystrophy (PPCD) is an autosomal dominant disorder characterized by corneal endothelial abnormalities, which can lead to blindness due to loss of corneal transparency and sometimes glaucoma. We mapped a new locus responsible for PPCD in a family in which we excluded the previously reported PPCD locus on 20q11, and the region containing COL8A2 on chromosome 1. Results of a 317-marker genome scan provided significant evidence of linkage of PPCD to markers on chromosome 10, with single-point LOD scores of 2.63, 1.63, and 3.19 for markers D10S208 (at (circumflex)theta = 0.03), D10S1780 (at (circumflex)theta = 0.00), and D10S578 (at (circumflex)theta = 0.06). A maximum multi-point LOD score of 4.35 was found at marker D10S1780. Affected family members shared a haplotype in an 8.55 cM critical interval that was bounded by markers D10S213 and D10S578. Our finding of another PPCD locus, PPCD3, on chromosome 10 indicates that PPCD is genetically heterogeneous. Guttae, a common corneal finding sometimes observed along with PPCD, were found among both affected and unaffected members of the proband's sib ship, but were absent in the younger generations of the family. Evaluation of phenotypic differences between family members sharing the same affected haplotype raises questions about whether differences in disease severity, including differences in response to surgical interventions, could be due to genetic background or other factors independent of the PPCD3 locus. 相似文献
56.
Brian T. Butcher Carol E. ONeil Margaret A. Reed John E. Salvaggio Hans Weill 《The Journal of allergy and clinical immunology》1982,70(4):231-235
Toluene diisocyanate (TDI) sensitivity accompanied by nonspecific bronchial hyperresponsiveness occurs in approximately 5% of occupationally exposed workers. We report the case of a 32-yr-old worker followed longitudinally after removal from isocyanate exposure. TDI reactivity was lost 11 mo after removal from exposure and nonspecific bronchial hyperresponsiveness resolved after 17 mo. Bronchial reactivity to radishes (Raphanus sativus), which developed concurrently with TDI reactivity, was lost 2 yr later. Immunopharmacologic results show that the worker's initial decreased ability of lymphocytes to produce cyclic AMP returned to near normal after 2 yr. IgE antibodies to a human serum albumin tolyl monoisocyanate conjugate were still present at this time. 相似文献
57.
Sizes, laminar and topographic origins of cortical projections to the major divisions of the red nucleus in the monkey 总被引:3,自引:0,他引:3
The retrograde transport of horseradish peroxidase was used to study the topographic and laminar origins of the cortical projections to the parvocellular and the magnocellular divisions of the red nucleus in Macaca mulatta and Macaca fascicularis. Approximately 90% of the corticorubral projection is directed to the parvocellular division of the nucleus. Corticoparvocellular (CRp) neurons are pyramidally shaped, are smaller in size than corticospinal neurons, and are more numerous. They are found principally in sublamina Va of cytoarchitectonic areas 4 and 6, and in moderate quantities in sublamina Vb of posterior area 8 and area 5. In areas 4 and 6, the cells are grouped in clusters of three to 15 neurons each and are arranged in cellular bands of varying rostrocaudal thickness which course mediolaterally. With respect to functionally defined zones, CRp neurons are found throughout the supplementary motor area and the precentral motor cortex. In addition, they are found in parts of areas 5, 6, and 24 that project to these cortical motor areas, and that are thought to have "premotor" or movement-programming functions. The corticomagnocellular (CRm) projection arises principally from cells in sublamina Vb of the precentral arm and leg areas (area 4), and from adjacent parts of posterior area 6, CRm cells are pyramidally shaped, and their size distribution is bimodal, with peaks that correspond, respectively, to the modal diameters of CRp and of corticospinal neurons. These results and those of previous studies suggest that CRm neurons are involved principally in the control of hand and foot movements, with little effect on more proximal musculature. The massive CRp projection, however, is clearly part of a large cerebrocerebellar communication system, with motor and/or movement programming functions that have yet to be clearly defined. 相似文献
58.
Ryan Schutt Jamie Case Sunil M. Kurian Samantha R. Spierling Bagsic Bethany L. Barrick Alice E. Toll Qiuheng Zhang Elaine F. Reed Michael M. Quigley Randolph Schaffer Jonathan S. Fisher James C. Rice Christopher L. Marsh 《Transplantation proceedings》2021,53(3):950-961
Although interest in the role of donor-specific antibodies (DSAs) in kidney transplant rejection, graft survival, and histopathological outcomes is increasing, their impact on steroid avoidance or minimization in renal transplant populations is poorly understood. Primary outcomes of graft survival, rejection, and histopathological findings were assessed in 188 patients who received transplants between 2012 and 2015 at the Scripps Center for Organ Transplantation, which follows a steroid avoidance protocol. Analyses were performed using data from the United Network for Organ Sharing. Cohorts included kidney transplant recipients with de novo DSAs (dnDSAs; n = 27), preformed DSAs (pfDSAs; n = 15), and no DSAs (nDSAs; n = 146). Median time to dnDSA development (classes I and II) was shorter (102 days) than in previous studies. Rejection of any type was associated with DSAs to class I HLA (P < .05) and class II HLA (P < .01) but not with graft loss. Although mean fluorescence intensity (MFI) independently showed no association with rejection, an MFI >5000 showed a trend toward more antibody-mediated rejection (P < .06), though graft loss was not independently associated. Banff chronic allograft nephropathy scores and a modified chronic injury score were increased in the dnDSA cohort at 6 months, but not at 2 years (P < .001 and P < .08, respectively). Our data suggest that dnDSAs and pfDSAs impact short-term rejection rates but do not negatively impact graft survival or histopathological outcomes at 2 years. Periodic protocol post-transplant DSA monitoring may preemptively identify patients who develop dnDSAs who are at a higher risk for rejection. 相似文献
59.
60.