全文获取类型
收费全文 | 860篇 |
免费 | 57篇 |
国内免费 | 45篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 41篇 |
妇产科学 | 29篇 |
基础医学 | 77篇 |
口腔科学 | 14篇 |
临床医学 | 105篇 |
内科学 | 309篇 |
皮肤病学 | 39篇 |
神经病学 | 30篇 |
特种医学 | 129篇 |
外科学 | 61篇 |
综合类 | 22篇 |
预防医学 | 19篇 |
眼科学 | 6篇 |
药学 | 51篇 |
中国医学 | 1篇 |
肿瘤学 | 26篇 |
出版年
2020年 | 3篇 |
2019年 | 6篇 |
2018年 | 12篇 |
2017年 | 9篇 |
2015年 | 6篇 |
2014年 | 12篇 |
2013年 | 19篇 |
2012年 | 16篇 |
2011年 | 19篇 |
2010年 | 33篇 |
2009年 | 30篇 |
2008年 | 21篇 |
2007年 | 45篇 |
2006年 | 19篇 |
2005年 | 22篇 |
2004年 | 14篇 |
2003年 | 18篇 |
2002年 | 15篇 |
2001年 | 16篇 |
2000年 | 14篇 |
1999年 | 21篇 |
1998年 | 42篇 |
1997年 | 36篇 |
1996年 | 39篇 |
1995年 | 26篇 |
1994年 | 21篇 |
1993年 | 24篇 |
1992年 | 24篇 |
1991年 | 20篇 |
1990年 | 22篇 |
1989年 | 40篇 |
1988年 | 51篇 |
1987年 | 29篇 |
1986年 | 27篇 |
1985年 | 22篇 |
1984年 | 20篇 |
1983年 | 20篇 |
1982年 | 19篇 |
1981年 | 9篇 |
1980年 | 11篇 |
1979年 | 7篇 |
1978年 | 11篇 |
1977年 | 16篇 |
1976年 | 8篇 |
1975年 | 5篇 |
1971年 | 6篇 |
1969年 | 4篇 |
1967年 | 7篇 |
1966年 | 3篇 |
1965年 | 3篇 |
排序方式: 共有962条查询结果,搜索用时 15 毫秒
1.
Alfred E Buxton Hugh Calkins David J Callans John P DiMarco John D Fisher H Leon Greene David E Haines David L Hayes Paul A Heidenreich John M Miller Athena Poppas Eric N Prystowsky Mark H Schoenfeld Peter J Zimetbaum Paul A Heidenreich David C Goff Frederick L Grover David J Malenka Eric D Peterson Martha J Radford Rita F Redberg 《Journal of the American College of Cardiology》2006,48(11):2360-2396
2.
3.
We used arthrotomography to study the glenoid labrum in 114 patients. Sixty-nine of the patients had anatomic instability of the shoulder (including recurrent dislocation and subluxation of the shoulder), and 45 patients had functional instability of the shoulder (denoted by chronic pain, clicking of the joint, and the sensation that an unstable condition exists without the objective signs of it). Labral tears were revealed arthrotomographically in 86% of the patients with anatomic instability, while only 40% of the patients with functional instability had labral abnormalities, and these were primarily of minor severity. Fifty-six patients (44 of whom had anatomic instability; 12, functional instability) required surgery. The surgical findings were correlated with the arthrotomographic findings, and no false-positive results were revealed. However, arthrotomography demonstrated only part of the pathologic condition of two patients. These results confirm that there is a strong correlation between labral pathologic conditions and anatomic instability of the shoulder. Arthrotomographic studies have a great impact on the selection of therapy in cases of both anatomic and functional instability of the shoulder. 相似文献
4.
Y Mahomed R D King D P Zipes W M Miles E N Prystowsky J J Heger J W Brown 《The Annals of thoracic surgery》1988,45(5):495-504
Kent bundle interruption for ventricular preexcitation has been successfully accomplished utilizing several different surgical techniques. The external closed-heart technique of Guiraudon combining surgical dissection and cryoablation has been used to interrupt 52 accessory pathways in 47 consecutive patients since May, 1985. The 35 male and 12 female patients ranged in age from 10 to 67 years (mean, 30 years). There were 25 left free wall, 13 right free wall, 13 posterior septal, and 1 anterior septal accessory pathways. Preoperative and intraoperative electrophysiological studies were performed in all patients to induce the arrhythmia and localize all accessory pathways. The operation consisted of dissection of the atrioventricular fat pad. Following this, the delta wave and retrograde accessory pathway conduction disappeared, thereby indicating successful pathway ablation. In 4 patients with right-sided accessory pathways, interruption of the pathway required cryoablation. Cryolesions (made with cryoprobe at -60 degrees C for two minutes) were created in the region of the accessory pathway insertion. All accessory pathways were successfully ablated without any deaths or heart block. Concomitant surgical procedures were performed in 4 patients. Two patients required a second operation the next day for an accessory pathway not found at the initial operation. Three patients had postpericardiotomy syndrome, and 4 had recurrent atrial fibrillation requiring therapy. The remaining patients have had no arrhythmia recurrence and have remained drug free after a follow-up of 1 month to 22 months (mean, 12.5 months). We conclude that the closed-heart technique of accessory pathway ablation is safe and reproducible, obviates the necessity for aortic cross-clamping and cardioplegic arrest, and allows instantaneous monitoring of conduction over the pathway. 相似文献
5.
6.
7.
Abstract We previously demonstrated that epidermal growth factor (EGF) induces a several-fold increase in ornithine decarboxylase (ODC) activity and the steady-state level of ODC mRNA in cultured SV40-transformed human keratinocytes (1). Pretreatment of cell cultures with ultraviolet B (UVB) radiation resulted in a reduction of EGF-induced ODC activity. To determine whether UVB inhibits the accumulation of ODC mRNA by EGF, cells were pretreated with 20 mJ/cm2 UVB or sham-irradiated and then incubated with 100 ng/ml EGF. Northern blot analysis revealed that UVB irradiation entirely blocked the EGF induction of ODC mRNA. Since the binding of EGF to its plasma membrane receptor is the first step in initiating a biological response, the effect of UVB on EGF binding was evaluated. UVB treatment of cultured keratinocytes resulted in an immediate and dose-dependent reduction of EGF binding. Scatchard analysis revealed thai the reduction of EGF binding was due to a 52% decrease in the number of available receptors, from 6.2 × 104/cell to 3.0 × 104/cell. However, UVB decreased the EGF-binding affinity very little (Kd = 0.60 nM in control and Kd=0.75 nM in UVB-treated Z114 cells). In addition, UVB did not alter the rate of EGF internalization. These data suggest that UVB blocks the signal transduction pathway of EGF that is involved in regulation of ODC gene expression. Immunoblot analysis of extracts from irradiated cells showed that UVB induced tyro-sine phosphorylation of EGFR and that the quantity of EGFR protein was unaffected by UVB treatment. Phosphorylation of EGFR may be responsible for decreased binding of EGF to its receptor. 相似文献
8.
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
9.
10.
Multiple hemopoietic lineages are found after stimulation of mouse bone marrow precursor cells with interleukin 3 总被引:5,自引:1,他引:5
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)
M B Prystowsky G Otten M F Naujokas J Vardiman J N Ihle E Goldwasser F W Fitch 《The American journal of pathology》1984,117(2):171-179
When the murine T-lymphocyte clone L2 is stimulated with concanavalin A, it secretes at least two distinct factors that affect hemopoietic precursor cells, interleukin 3 (IL3) and granulocyte/macrophage colony-stimulating factor (GM-CSF). IL3 accounts for approximately 10% of the colony-stimulating activity in L2-cell-conditioned medium. The IL3 secreted by L2 cells is similar antigenically to the IL3 secreted by WEHI-3 cells. Like the IL3 from WEHI-3 cells, IL3 secreted by L2 cells does not bind to DEAE Sephacel and can be separated from the L2-cell GM-CSF, which does bind to DEAE. By assessment of the functional, morphologic, surface phenotypic, and cytochemical characteristics of bone marrow cells 6 days after stimulation with IL3 in liquid culture, four hemopoietic lineages were found, including macrophage, neutrophilic granulocyte, megakaryocyte, and basophil/mast cell. In addition, when bone marrow cells were stimulated with IL3 in semisolid medium, several types of colonies were found, including mixed colonies containing macrophage, megakaryocyte, and granulocyte lineages. 相似文献