全文获取类型
收费全文 | 7815篇 |
免费 | 690篇 |
国内免费 | 25篇 |
专业分类
耳鼻咽喉 | 120篇 |
儿科学 | 252篇 |
妇产科学 | 123篇 |
基础医学 | 1000篇 |
口腔科学 | 246篇 |
临床医学 | 719篇 |
内科学 | 1665篇 |
皮肤病学 | 160篇 |
神经病学 | 618篇 |
特种医学 | 419篇 |
外国民族医学 | 1篇 |
外科学 | 1041篇 |
综合类 | 96篇 |
预防医学 | 560篇 |
眼科学 | 161篇 |
药学 | 481篇 |
中国医学 | 37篇 |
肿瘤学 | 831篇 |
出版年
2023年 | 28篇 |
2022年 | 75篇 |
2021年 | 184篇 |
2020年 | 116篇 |
2019年 | 229篇 |
2018年 | 257篇 |
2017年 | 180篇 |
2016年 | 181篇 |
2015年 | 231篇 |
2014年 | 310篇 |
2013年 | 376篇 |
2012年 | 415篇 |
2011年 | 444篇 |
2010年 | 287篇 |
2009年 | 273篇 |
2008年 | 368篇 |
2007年 | 383篇 |
2006年 | 322篇 |
2005年 | 325篇 |
2004年 | 291篇 |
2003年 | 261篇 |
2002年 | 249篇 |
2001年 | 196篇 |
2000年 | 226篇 |
1999年 | 179篇 |
1998年 | 145篇 |
1997年 | 110篇 |
1996年 | 105篇 |
1995年 | 91篇 |
1994年 | 97篇 |
1993年 | 94篇 |
1992年 | 118篇 |
1991年 | 123篇 |
1990年 | 115篇 |
1989年 | 157篇 |
1988年 | 102篇 |
1987年 | 107篇 |
1986年 | 85篇 |
1985年 | 65篇 |
1984年 | 75篇 |
1983年 | 44篇 |
1982年 | 49篇 |
1981年 | 57篇 |
1980年 | 39篇 |
1979年 | 53篇 |
1978年 | 28篇 |
1977年 | 46篇 |
1976年 | 39篇 |
1975年 | 28篇 |
1971年 | 27篇 |
排序方式: 共有8530条查询结果,搜索用时 15 毫秒
71.
72.
HL-A antigens in leprosy 总被引:1,自引:0,他引:1
73.
E.G. De la Concha M. Fernandez-Arquero J.L. Mendoza L. Conejero M.A. Figueredo J. Perez de la Sema M. Diaz-Rubio A. Ruiz de Leon 《Tissue antigens》1998,52(4):381-384
Abstract: Achalasia is a motor disorder of the esophagus resulting in functional obstruction. The cause of the lesion is unknown although genetic and immunologic factors have been suggested. An association with serological HLA epitopes has been previously reported. In this study, we have further examined this HLA class II association with susceptibility to achalasia by DNA based methods. Achalasia patients ( n =40) and healthy controls ( n = 275), all Caucasians and unrelated, were included in the analysis. The strongest associations were with HLA-DQAl*0101 and two HLA-DQαβ heterodimers having their a chain encoded by this allele. Moreover, relative risk was significantly higher in DQAl*0101 homozygotes as compared to heterozygotes and results suggested that DQB1*02 may have a protective role. 相似文献
74.
Elastin point mutations cause an obstructive vascular disease, supravalvular aortic stenosis 总被引:7,自引:2,他引:7
Li DY; Toland AE; Boak BB; Atkinson DL; Ensing GJ; Morris CA; Keating MT 《Human molecular genetics》1997,6(7):1021-1028
Supravalvular aortic stenosis (SVAS) is an inherited obstructive vascular
disease that affects the aorta, carotid, coronary and pulmonary arteries.
Previous molecular genetic data have led to the hypothesis that SVAS
results from mutations in the elastin gene, ELN. In these studies, the
disease phenotype was linked to gross DNA rearrangements (35 and 85 kb
deletions and a translocation) in three SVAS families. However, gross
rearrangements of ELN have not been identified in most cases of autosomal
dominant SVAS. To define the spectrum of ELN mutations responsible for this
disorder, we refined the genomic structure of human ELN and used this
information in mutational analyses. ELN point mutations co-segregate with
the disease in four familial cases and are associated with SVAS in three
sporadic cases. Two of the mutations are nonsense, one is a single base
pair deletion and four are splice site mutations. In one sporadic case, the
mutation arose de novo. These data demonstrate that point mutations of ELN
cause autosomal dominant SVAS.
相似文献
75.
Presynaptic control of group Ia afferents in relation to acquisition of a visuo-motor skill in healthy humans 总被引:2,自引:3,他引:2
Monica A. Perez Bjarke K. S. Lungholt Jens B. Nielsen 《The Journal of physiology》2005,568(1):343-354
Sensory information continuously converges on the spinal cord during a variety of motor behaviours. Here, we examined presynaptic control of group Ia afferents in relation to acquisition of a novel motor skill. We tested whether repetition of two motor tasks with different degrees of difficulty, a novel visuo-motor task involving the ankle muscles, and a control task involving simple voluntary ankle movements, would induce changes in the size of the soleus H-reflex. The slope of the H-reflex recruitment curve and the H-max/M-max ratio were depressed after repetition of the visuo-motor skill task and returned to baseline after 10 min. No changes were observed after the control task. To elucidate the mechanisms contributing to the H-reflex depression, we measured the size of the long-latency depression of the soleus H-reflex evoked by peroneal nerve stimulation (D1 inhibition) and the size of the monosynaptic Ia facilitation of the soleus H-reflex evoked by femoral nerve stimulation. The D1 inhibition was increased and the femoral nerve facilitation was decreased following the visuo-motor skill task, suggesting an increase in presynaptic inhibition of Ia afferents. No changes were observed in the disynaptic reciprocal Ia inhibition. Somatosensory evoked potentials (SEPs) evoked by stimulation of the tibial nerve (TN) were also unchanged, suggesting that transmission in ascending pathways was unaltered following the visuo-motor skill task. Together these observations suggest that a selective presynaptic control of Ia afferents contributes to the modulation of sensory inputs during acquisition of a novel visuo-motor skill in healthy humans. 相似文献
76.
Primary gastroesophageal-ileal hodgkin lymphoma 总被引:1,自引:0,他引:1
Perez MT Cabello-Inchausti B Castellano-Sanchez A Kottiech S Davila E Willis I Barkin J 《Archives of pathology & laboratory medicine》2002,126(12):1534-1537
Primary Hodgkin lymphoma of the gastrointestinal tract is exceedingly rare to the point that some authors regard with skepticism the existence of this entity. Cases of gastrointestinal Hodgkin lymphoma have been reported previously; however, most of these cases represented secondary involvement of the digestive tract in the context of systemic disease. Other cases have been reclassified in retrospective studies as non-Hodgkin lymphomas after the application of immunohistochemical techniques. We report a case of primary Hodgkin lymphoma of the gastrointestinal tract in a patient who presented with obstructive symptoms at the site of a gastroileal bypass; the bypass had been performed years earlier because of morbid obesity. Some non-Hodgkin lymphomas may morphologically mimic Hodgkin lymphoma and vice versa; therefore, an accurate pathologic diagnosis is important, since the therapeutic approach and prognostic implications differ significantly for these diseases. In this context, immunohistochemistry should be used to confirm or to exclude the histologic diagnosis of Hodgkin lymphoma. 相似文献
77.
78.
The polymeric immunoglobulin A receptor is present on hepatocytes in human liver. 总被引:1,自引:0,他引:1 下载免费PDF全文
A monoclonal antibody raised against human colostrum secretory component produced even staining of hepatocyte plasma membranes, as well as bile duct lining cells, in all sections examined from eight normal and three abnormal human livers. Human bile samples incubated with free secretory component degraded it to varying extents, probably proteolytically; true levels of free secretory component will therefore often be higher than those reported. It seems likely that human liver resembles that of other mammals in transferring polymeric IgA through hepatocytes to the bile by means of the polymeric IgA receptor. 相似文献
79.
Regulation of experimental autoimmune encephalomyelitis by CD4+, CD25+ and CD8+ T cells: analysis using depleting antibodies 总被引:6,自引:0,他引:6
Montero E Nussbaum G Kaye JF Perez R Lage A Ben-Nun A Cohen IR 《Journal of autoimmunity》2004,23(1):1-7
Experimental Autoimmune Encephalomyelitis (EAE) can be induced in mice of the C57BL/6 strain by subcutaneous immunization with myelin/oligodendrocyte glycoprotein (MOG) peptide p35-55 in CFA, administered twice at an interval of one week and supplemented with Bordetella pertussis toxin given IV. Here, we studied the effect on the induction of EAE of depleting antibodies to CD4, CD8, or CD25 administered before either the first or the second dose of MOG p35-55. We found that anti-CD4 abolished EAE when given before the first immunization; anti-CD4 did not affect the disease when it was given before the second immunization. Anti-CD8 enhanced EAE induction when given before either of the two immunizations. Anti-CD25 enhanced EAE to the same degree as anti-CD8 when given before the first immunization, but anti-CD25 was even more effective in enhancing EAE when given before the second immunization. The anti-CD25 treatment led to significantly enhanced IFNgamma production by T cells responding to MOG p35-55 and persisting anti-MOG antibodies detectable 56 days after the first immunization. Administration of anti-CD8 or anti-CD25 abolished the need for pertussis toxin to induce EAE. These findings are compatible with the idea that CD4 T cells are required for the initial induction of EAE and that the disease is down-regulated by T cells expressing CD8 or CD25. These regulatory T cells exist prior to MOG immunization, but the CD25+ regulators appear to be further amplified by immunization. 相似文献
80.
Marta Zelazko Magda Carneiro-Sampaio Monica Cornejo De Luigi Diana Garcia De Olarte Oscar Porras Madrigal Renato Berrón Perez Agueda Cabello Marylin Valentin Rostan Ricardo U. Sorensen 《Journal of clinical immunology》1998,18(2):161-166
The Latin American Group for Primary Immunodeficiencies, formed in 1993, presently includes 12 countries. One goal was to study the frequency of primary immunodeficiencies in various regions of the American continent and to enhance knowledge about these diseases among primary-care physicians, as well as allergist–immunologists. Important for this purpose was the development of a registry of primary immunodeficiencies using a uniform questionnaire and computerized database. To date, eight countries have collected information on a total of 1428 patients. Predominantly antibody deficiencies were reported in 58% of patients, followed by cellular and antibody immunodeficiencies associated with other abnormalities in 18%, immunodeficiency syndromes associated with granulocyte dysfunction in 8%, phagocytic disorders in 9%, combined cellular and antibody immunodeficiencies in 5%, and complement deficiencies in 2% of patients. The information gathered from this initial analysis of data will serve to expand the patient database to more areas within participating countries and to new countries and to increase collaboration toward better diagnosis and treatment of these diseases. 相似文献