全文获取类型
收费全文 | 3923篇 |
免费 | 242篇 |
国内免费 | 127篇 |
专业分类
耳鼻咽喉 | 18篇 |
儿科学 | 117篇 |
妇产科学 | 79篇 |
基础医学 | 566篇 |
口腔科学 | 29篇 |
临床医学 | 358篇 |
内科学 | 996篇 |
皮肤病学 | 230篇 |
神经病学 | 150篇 |
特种医学 | 455篇 |
外国民族医学 | 3篇 |
外科学 | 583篇 |
综合类 | 44篇 |
预防医学 | 139篇 |
眼科学 | 73篇 |
药学 | 225篇 |
中国医学 | 11篇 |
肿瘤学 | 216篇 |
出版年
2023年 | 18篇 |
2022年 | 26篇 |
2021年 | 44篇 |
2020年 | 37篇 |
2019年 | 46篇 |
2018年 | 81篇 |
2017年 | 36篇 |
2016年 | 60篇 |
2015年 | 67篇 |
2014年 | 95篇 |
2013年 | 125篇 |
2012年 | 138篇 |
2011年 | 172篇 |
2010年 | 134篇 |
2009年 | 127篇 |
2008年 | 157篇 |
2007年 | 212篇 |
2006年 | 151篇 |
2005年 | 205篇 |
2004年 | 142篇 |
2003年 | 126篇 |
2002年 | 122篇 |
2001年 | 93篇 |
2000年 | 124篇 |
1999年 | 122篇 |
1998年 | 130篇 |
1997年 | 117篇 |
1996年 | 124篇 |
1995年 | 80篇 |
1994年 | 77篇 |
1993年 | 79篇 |
1992年 | 71篇 |
1991年 | 81篇 |
1990年 | 90篇 |
1989年 | 103篇 |
1988年 | 86篇 |
1987年 | 82篇 |
1986年 | 61篇 |
1985年 | 71篇 |
1984年 | 43篇 |
1983年 | 31篇 |
1982年 | 35篇 |
1981年 | 23篇 |
1980年 | 36篇 |
1979年 | 31篇 |
1978年 | 23篇 |
1977年 | 26篇 |
1976年 | 30篇 |
1975年 | 26篇 |
1973年 | 11篇 |
排序方式: 共有4292条查询结果,搜索用时 15 毫秒
31.
Image-directed percutaneous biopsies with a biopsy gun 总被引:3,自引:0,他引:3
Core tissue for histologic study is believed by many pathologists to be more diagnostic than material from needle aspiration. Recently, a biopsy "gun" has been introduced, which simplifies core biopsies. With this device, 182 biopsies of multiple anatomic sites were performed with ultrasonic, computed tomographic, and fluoroscopic guidance and 18-gauge needles. High-quality histopathologic specimens were obtained in 177 of the biopsies, and diagnostic target tissue was obtained in 167. Only three significant complications occurred: one bleeding complication that required transfusion and two cases of pneumothorax that necessitated placement of chest tubes. The biopsy gun eliminated the disjointed movements of conventional "skinny" needle biopsies, and none of the samples demonstrated significant "crush" artifact or obscuring blood, problems that are commonly associated with manual biopsy techniques. Patient discomfort was decreased with this system compared with that of manual biopsies, and the total procedure time was reduced. Because of these distinct advantages, the authors now use the biopsy gun exclusively for all percutaneous biopsies and recommend that other institutions consider the use of this biopsy method. 相似文献
32.
新生期大白鼠皮下注射谷氨酸单钠对成年后下丘脑α-促黑素细胞激素神经元免疫反应性的影响 总被引:2,自引:0,他引:2
本文用免疫组化方法研究了新生期大白鼠注射谷氨酸单钠(MSG)对成年后下丘脑α-促黑素细胞激素(α-MSH)免疫反应神经元的影响,结果显示MSG处理以后下丘脑弓状核区α-MSII免疫反应神经元减少甚至完全消失,但不影响下丘脑背外侧区的α-MSH神经元群。文中还讨论了这两群α-MSH神经元的生理作用。 相似文献
33.
Linkage of the MHC to familial multiple sclerosis suggests genetic heterogeneity. The Multiple Sclerosis Genetics Group 总被引:5,自引:0,他引:5
Haines JL; Terwedow HA; Burgess K; Pericak-Vance MA; Rimmler JB; Martin ER; Oksenberg JR; Lincoln R; Zhang DY; Banatao DR; Gatto N; Goodkin DE; Hauser SL 《Human molecular genetics》1998,7(8):1229-1234
Multiple sclerosis (MS) is a demyelinating autoimmune disease of the
central nervous system. While its etiology is not well understood, genetic
factors are clearly involved. Until recently, most genetic studies in MS
have been association studies using the case-control design testing
specific candidate genes and studying only sporadic cases. The only
consistently replicated finding has been an association with the HLA-DR2
allele within the major histocompatibility complex (MHC) on chromosome 6.
Using the genetic linkage design, however, evidence for and against linkage
of the MHC to MS has been found, fostering suggestions that sporadic and
familial MS have different etiologies. Most recently, two of four genomic
screens demonstrated linkage to the MHC, although specific allelic
associations were not tested. Here, a dataset of 98 multiplex families was
studied to test for an association to the HLA-DR2 allele in familial MS and
to determine if genetic linkage to the MHC was due solely to such an
association. Three highly polymorphic markers (HLA-DR, D6S273 and TNFbeta)
in the MHC demonstrated strong genetic linkage (parametric lod scores of
4.60, 2.20 and 1.24, respectively) and a specific association with the
HLA-DR2 allele was confirmed (TDT; P < 0.001). Stratifying the results
by HLA-DR2 status showed that the linkage results were limited to families
segregating HLA-DR2 alleles. These results demonstrate that genetic linkage
to the MHC can be explained by the HLA-DR2 allelic association. They also
indicate that sporadic and familial MS share a common genetic
susceptibility. In addition, preliminary calculations suggest that the MHC
explains between 17 and 62% of the genetic etiology of MS. This
heterogeneity is also supported by the minority of families showing no
linkage or association with loci within the MHC.
相似文献
34.
CTLA-4 is required for the induction of high dose oral tolerance 总被引:5,自引:3,他引:5
Samoilova EB; Horton JL; Zhang H; Khoury SJ; Weiner HL; Chen Y 《International immunology》1998,10(4):491-498
Mucosal and systemic administrations of high dose antigens induce long-
lasting peripheral T cell tolerance. We and others have shown that high
dose peripheral T cell tolerance is mediated by anergy or deletion and is
preceded by T cell activation. Co-stimulatory molecules B7-1 (CD80)/B7-2
(CD86) and their counter-receptors CD28/CTLA-4 play pivotal roles in T cell
activation and immune regulation. In the present study, we examined the
roles of the B7 co-stimulation pathway in the generation of high dose
peripheral T cell tolerance. We found that blocking B7:CD28/CTLA-4
interaction at the time of tolerance induction partially prevented T cell
tolerance, whereas selective blockade of B7:CTLA-4 interaction completely
abrogated peripheral T cell tolerance induced by either oral or i.p.
antigens. These results suggest that CTLA-4-mediated feedback regulation
plays a crucial role in the induction of high dose peripheral T cell
tolerance.
相似文献
35.
Screening for proteins with polyglutamine expansions in autosomal dominant cerebellar ataxias 总被引:2,自引:8,他引:2
Stevanin G; Trottier Y; Cancel G; Durr A; David G; Didierjean O; Burk K; Imbert G; Saudou F; Abada-Bendib M; Gourfinkel-An I; Benomar A; Abbas N; Klockgether T; Grid D; Agid Y; Mandel JL; Brice A 《Human molecular genetics》1996,5(12):1887-1892
Expansion of trinucleotide CAG repeats coding for polyglutamine has been
implicated in five neurodegenerative disorders, including spinocerebellar
ataxia (SCA) 1 and SCA3 or Machado-Joseph disease (SCA3/MJD), two forms of
type I autosomal dominant cerebellar ataxias (ADCA). Using the 1C2 antibody
which specifically recognizes large polyglutamine tracts, particularly
those that are expanded, we recently reported the detection of proteins
with pathological glutamine expansions in lymphoblasts from another form of
ADCA type I, SCA2, as well as from patients presenting with the distinct
phenotype of ADCA type II. We now have screened a large series of patients
with ADCA or isolated cases with cerebellar ataxia, for the presence of
proteins with polyglutamine expansions. A 150 kDa SCA2 protein was detected
in 16 out of 40 families with ADCA type I. This corresponds to 24% of all
ADCA type I families, which is much more frequent than SCA1 in this series
of patients (13%). The signal intensity of the SCA2 protein was negatively
correlated to age at onset, as expected for an expanded and unstable
trinucleotide repeat mutation. The disease segregated with markers closely
linked to the SCA2 locus in all identified SCA2 families. In addition, a
specific 130 kDa protein, which segregated with the disease, was detected
in lymphoblasts of patients from nine families with ADCA type II. It was
also visualized in the cerebral cortex of one of the patients,
demonstrating its translation in the nervous system. Finally, no new
disease-related proteins containing expanded polyglutamine tracts could be
detected in lymphoblasts from the remaining patients with ADCA or isolated
cases with cerebellar ataxia.
相似文献
36.
Fine antigenic specificities of antibodies in sera from patients with D-penicillamine-induced myasthenia gravis.
下载免费PDF全文
![点击此处可从《Clinical and experimental immunology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
S J Tzartos E Morel A Efthimiadis A F Bustarret J D''''Anglejan A A Drosos H A Moutsopoulos 《Clinical and experimental immunology》1988,74(1):80-86
A small fraction of patients with rheumatoid arthritis and other diseases on D-penicillamine treatment may develop antibodies against the acetylcholine receptor (AChR) and symptoms of myasthenia gravis (MG). The mechanism leading to this phenomenon is not known. We have studied the fine antigenic specificities of the anti-AChR antibodies in 19 D-penicillamine-induced MG (pen-MG) patients and compared them with those of antibodies from 204 idiopathic MG patients (the data for 122 obtained from earlier experiments). Antigenic specificities of the circulating antibodies were determined by the capacity of monoclonal antibodies (MoAbs), against certain determinants on the AChR, to inhibit binding of the serum antibodies to the AChR. Monoclonal antibodies against alpha, beta and gamma subunits were used. The anti-AChR antibody patterns of pen-MG patients were very similar to those of idiopathic MG patients. Antibodies to the main immunogenic region, which is located on the extracellular surface of the alpha-subunit, were the predominant group. The variations of antibody specificities in serial sera collected from individual patients at different times were usually small, as were those of idiopathic MG. These results strongly suggest that the antibody repertoire in the sera of idiopathic and pen-MG patients is very similar. 相似文献
37.
Role of Eotaxin-1 (CCL11) and CC chemokine receptor 3 (CCR3) in bleomycin-induced lung injury and fibrosis
下载免费PDF全文
![点击此处可从《The American journal of pathology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Huaux F Gharaee-Kermani M Liu T Morel V McGarry B Ullenbruch M Kunkel SL Wang J Xing Z Phan SH 《The American journal of pathology》2005,167(6):1485-1496
Eotaxin-1/CCL11 and its receptor CCR3 are involved in recruitment of eosinophils to diverse tissues, but their role in eosinophil recruitment in pulmonary fibrosis is unclear. The present study examined the pulmonary expression of CCL11 and CCR3 during bleomycin (blm)-induced lung injury and determined their importance in the recruitment of inflammatory cells and the development of lung fibrosis. In mice, blm induced a marked pulmonary expression of CCL11 and CCR3. Immunostaining for CCR3 revealed that this receptor was not only expressed by eosinophils but also by neutrophils. CCL11-deficient (CCL11(-/-)) mice developed significantly reduced pulmonary fibrosis. Expression of profibrotic cytokines such as transforming growth factor-beta1 was diminished in the absence of CCL11. Furthermore, increased lung expression of CCL11 significantly enhanced blm-induced lung fibrosis and production of profibrotic cytokines. These effects were also associated with an increase of eosinophil and neutrophil pulmonary infiltration. In contrast, mice treated with neutralizing CCR3 antibodies developed significantly reduced pulmonary fibrosis, eosinophilia, neutrophilia, and expression of profibrotic cytokines. Together, these data suggest that CCL11 and CCR3 are important in the pulmonary recruitment of granulocytes and play significant pathogenic roles in blm-induced lung fibrosis. 相似文献
38.
N. M. Griffiths D. Chabardès M. Imbert-Teboul S. Siaume-Perez F. Morel N. L. Simmons 《Pflügers Archiv : European journal of physiology》1988,412(4):363-368
The effect of vasoactive intestinal peptide (VIP) upon adenylate cyclase (AC) activity has been determined in defined microdissected renal tubules isolated from collagenase-treated rabbit kidneys. In the presence of 10 M GTP, 1 M VIP gave marked stimulations of AC over basal values in the bright portion of the distal convoluted tubule (DCTb) (10.1-fold), and in the collecting tubule isolated from the inner stripe of the outer medulla (OMCTi, 7.8-fold). Less pronounced effects of VIP were found in the medullary collecting tubule isolated from the outer stripe (2.5-fold) and in the granular portion of the distal convoluted tubule (2.0-fold). VIP stimulation of AC activity in these segments amounted to 25 to 40% of the effect elicited by other agonists (arginine vasopressin, calcitonin or parathyroid hormone) in their respective target segments. A low response to VIP was observed in the cortical thick ascending limb (1.8-fold) which represented less than 5% of the calcitonin-stimulated AC activity. In the thin descending limb VIP produced a slight and variable stimulation of AC. VIP was without effect upon AC in the convoluted and straight portions of the proximal tubule, the medullary thick ascending limb and the cortical collecting tubule. Halfmaximal stimulation of AC by VIP was observed at 26±10 nM (n=3) in OMCTi and at 19 nM (n=2) in DCTb. Related peptides glucagon, secretin and PHI gave lower stimulations of AC compared to VIP in OMCTi. Conversely for rat OMCTi, under identical conditions, glucagon was much more effective than VIP. 相似文献
39.
Jamet D Marzin Y Douet-Guilbert N Morel F Le Bris MJ Herry A Banzakour S Bourquard P Morice P Abgrall JF Berthou C De Braekeleer M 《Cancer Genetics and Cytogenetics》2005,161(2):159-163
Jumping translocations (JT) have been defined as nonreciprocal translocations involving a same donor chromosome arm or chromosome segment onto two or more recipient chromosomes in different cell lines in the same patient, leading to a mosaic karyotype. This definition has been expanded to also include extra copies of a same donor segment on different recipient chromosomes in a single clone. Six patients with multiple myeloma and JT involving chromosome arm 1q were identified among 37 patients presenting with chromosome 1 abnormalities. All six patients had an advanced disease and a short survival. The literature review allowed us to identify 24 additional patients with JT. Chromosomes 16 and 19 were the recipients in 11 (45.8%) and 6 (25%) of these 24 patients, respectively. Breakpoints on the recipient chromosomes were pericentromeric in 46.2% and telomeric in 40.4% of the breakpoints recorded. Since telomeres are made of (TTAGGG)n tandem DNA repeats that are also found in the pericentromeric heterochromatic regions (interstital telomeric sequences), it is presumed that jumping translocations arise through illegimate recombination between telomere repeat sequences and interstitial telomeric sequences. 相似文献
40.