全文获取类型
收费全文 | 9969篇 |
免费 | 714篇 |
国内免费 | 34篇 |
专业分类
耳鼻咽喉 | 93篇 |
儿科学 | 370篇 |
妇产科学 | 152篇 |
基础医学 | 1432篇 |
口腔科学 | 155篇 |
临床医学 | 897篇 |
内科学 | 1860篇 |
皮肤病学 | 208篇 |
神经病学 | 1132篇 |
特种医学 | 470篇 |
外国民族医学 | 5篇 |
外科学 | 1465篇 |
综合类 | 78篇 |
一般理论 | 6篇 |
预防医学 | 521篇 |
眼科学 | 228篇 |
药学 | 960篇 |
中国医学 | 4篇 |
肿瘤学 | 681篇 |
出版年
2021年 | 117篇 |
2019年 | 99篇 |
2018年 | 148篇 |
2017年 | 97篇 |
2016年 | 148篇 |
2015年 | 181篇 |
2014年 | 187篇 |
2013年 | 293篇 |
2012年 | 378篇 |
2011年 | 434篇 |
2010年 | 234篇 |
2009年 | 222篇 |
2008年 | 350篇 |
2007年 | 402篇 |
2006年 | 408篇 |
2005年 | 364篇 |
2004年 | 427篇 |
2003年 | 399篇 |
2002年 | 323篇 |
2001年 | 341篇 |
2000年 | 332篇 |
1999年 | 269篇 |
1998年 | 126篇 |
1997年 | 134篇 |
1996年 | 127篇 |
1995年 | 101篇 |
1994年 | 86篇 |
1993年 | 94篇 |
1992年 | 220篇 |
1991年 | 224篇 |
1990年 | 213篇 |
1989年 | 251篇 |
1988年 | 226篇 |
1987年 | 207篇 |
1986年 | 194篇 |
1985年 | 214篇 |
1984年 | 137篇 |
1983年 | 98篇 |
1982年 | 90篇 |
1981年 | 89篇 |
1980年 | 85篇 |
1979年 | 144篇 |
1978年 | 98篇 |
1977年 | 93篇 |
1976年 | 114篇 |
1975年 | 111篇 |
1974年 | 96篇 |
1972年 | 74篇 |
1971年 | 87篇 |
1970年 | 83篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
101.
Epiphyseal dysplasia of the femoral head, mild vertebral abnormality, myopia, and sensorineural deafness: report of a pedigree with autosomal dominant inheritance. 下载免费PDF全文
A family is presented with short stature, femoral epiphyseal dysplasia, mild vertebral changes, and sensorineural deafness inherited as an autosomal dominant trait. Myopia and retinal detachment presenting in adult life were also present in some affected members. We suggest that this disorder may be a distinct entity within the spondyloepiphyseal dysplasia group of disorders. 相似文献
102.
103.
Tawil A Cox JN Roth AD Briner J Droz JP Remadi S 《Pathology, research and practice》1999,195(2):105-11; discussion 113-4
Wilms' tumor is rare in adults. Its histology, grading and staging are identical to those in children. Investigators agree on a combined modality approach in the treatment of adult Wilms' tumor (AWT), but differ on how aggressive it should be. Some advocate adopting the current pediatric protocols which take into account tumor stage and grade. Others recommend using advanced disease regimens for all stages and grades. We report on an 18 year-old male with stage IV favorable histology Wilms' tumor. The patient underwent radical nephrectomy and received postoperative radiotherapy with intensive four-drug chemotherapy. He had one relapse after 12 months which was successfully treated with chemotherapy and radiotherapy. He remains in remission without relapses 36 months after the initial diagnosis. The genetics of Wilms' tumor has been well studied in children but is practically unknown in adults; karyotype and molecular genetic studies in this case were normal. 相似文献
104.
The GAP-related domain of tuberin, the product of the TSC2 gene, is a target for missense mutations in tuberous sclerosis 总被引:5,自引:0,他引:5
Maheshwar MM; Cheadle JP; Jones AC; Myring J; Fryer AE; Harris PC; Sampson JR 《Human molecular genetics》1997,6(11):1991-1996
Tuberous sclerosis is an autosomal dominant trait in which the
dysregulation of cellular proliferation and differentiation results in the
development of hamartomatous growths in many organs. The TSC2 gene is one
of two genes determining tuberous sclerosis. Inactivating germline
mutations of TSC2 in patients with tuberous sclerosis and somatic loss of
heterozygosity at the TSC2 locus in the associated hamartomas indicate that
TSC2 functions as a tumour suppressor gene and that loss of function is
critical to expression of the tuberous sclerosis phenotype. The TSC2
product, tuberin, has a region of homology with the GTPase activating
protein rap1GAP and stimulates the GTPase activity of rap1a and rab5a in
vitro. Here we show that the region of homology between tuberin and human
rap1GAP and the murine GAP mSpa1 is more extensive than previously reported
and spans approximately 160 amino acid residues encoded within exons 34-38
of the TSC2 gene. Single strand conformation polymorphism analysis of these
exons in 173 unrelated patients with tuberous sclerosis and direct
sequencing of variant conformers together with study of additional family
members enabled characterisation of disease associated mutations in 14
cases. Missense mutations, which occurred in exons 36, 37 and 38 were
identified in eight cases, four of whom shared the same recurrent change
P1675L. Each of the five different missense mutations identified was shown
to occur de novo in at least one sporadic case of tuberous sclerosis. The
high proportion of missense mutations detected in the region of the TSC2
gene encoding the GAP-related domain supports its key role in the
regulation of cellular growth.
相似文献
105.
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
106.
107.
J Roth C Zuber 《Laboratory investigation; a journal of technical methods and pathology》1990,62(1):55-60
In previous studies we demonstrated the presence of polysialic acid in Wilms tumor by immunohistochemistry and immunoblotting. We now show by immunoelectron microscopy that the cell surface coat of Wilms tumor cells consists of a layer of amorphous material containing polysialic acid but not detectable amounts of laminin, laminin-nidogen complex, or low density proteoglycan. Therefore, Wilms tumor cells are covered by a highly developed and chemically specialized cell surface coat that does not represent a basement membrane, although it bears some structural similarities. Polysialic acid is present on neural cell adhesion molecule that exists in Wilms tumor as two isoforms of approximately 120 and 140 kDa. The cell surface coat exhibits variation in its thickness along the plasma membrane of a single tumor cell, and the variation is inversely related to the extent of cell-cell contact. It is therefore proposed that polysialic acid may modulate the behavior and invasive potential of Wilms tumor cells. 相似文献
108.
Dr. B. J. Roth 《Medical & biological engineering & computing》1989,27(5):491-495
Spatial and temporal frequency-dependent conductivities are used to interpret four-electrode conductivity measurements on
skeletal muscle. The model qualitatively explains the observed dependence of the experimental data on the temporal frequency
of the injected current, the angle between the electrode array and the fibre direction and the distance between the electrodes. 相似文献
109.
George J Barshack I Keren P Gazit A Levitzki A Keren G Roth A 《Experimental and molecular pathology》2005,78(3):233-238
BACKGROUND: Inflammation has been shown to play an important role in promoting the response to arterial injury and proinflammatory cytokines, such as tumor necrosis factor (TNF) alpha, are candidate mediators. AG-556 is a tyrosine kinase inhibitor proven to be effective in a model of multiple sclerosis-like syndrome in mice due to its immunomodulating effect. In the current study, we investigated the effect of the tyrphostin AG-556 on neointimal thickening and cytokine profile in a model of arterial injury in the mouse. METHODS: Injury was induced by external cuff placement on the left femoral artery of wild-type C57BL/6 mice. AG-556 dissolved in DMSO was injected intraperitoneally daily to the injured mice in a dosage of 2 mg/mouse. Control mice received DMSO injections. Histological analysis was carried out to assess neointimal formation. Splenocytes were cultured in the absence and presence of a mitogen for evaluation of thymidine incorporation and cytokine production. RESULTS: AG-556 treatment significantly attenuated intimal thickening (43,000+/-17,000 microm2; n=11) when compared to DMSO administration (286,000+/-127,000 microm2; n=10; P<0.05). Basal interferon-gamma production by splenocytes from AG-556-treated mice was increased by approximately 20-fold in comparison with levels in DMSO-treated animals, whereas Con-A induced secretion of the cytokine was similar between both groups. Levels of TNF-alpha, IL-4 and IL-10 in the culture supernatant from treated and non-treated animals did not differ significantly. CONCLUSION: The tyrosine kinase inhibitor AG-556 may have a role in the reduction of intimal thickening. The effect could be mediated via an immune modulating effect involving a significant increase in the smooth muscle cell inhibitory cytokine IFN-gamma. 相似文献
110.
For an effective radiotherapy the exact tumor location must be determined. The localization has to take into account patient's setup position as well as internal organ motion. Among the different localization methods, the use of a computer tomography (CT) scanner in the therapy room has been proposed recently. Achieving a CT with the patient on the therapy couch, a patient's treatment position is captured. We present a method to locate tumor considering internal organ motion and displacements due to respiration. We tested the method with prostate and lung patients. The method found the most probable tumor position as well as, for high-mobility tumors located in the lung, its trajectory during the respiratory cycle. The results of this novel method were validated by comparison with manually determined target position. 相似文献