全文获取类型
收费全文 | 16754篇 |
免费 | 1083篇 |
国内免费 | 46篇 |
专业分类
耳鼻咽喉 | 185篇 |
儿科学 | 1107篇 |
妇产科学 | 453篇 |
基础医学 | 2212篇 |
口腔科学 | 352篇 |
临床医学 | 1696篇 |
内科学 | 3327篇 |
皮肤病学 | 519篇 |
神经病学 | 1272篇 |
特种医学 | 341篇 |
外国民族医学 | 1篇 |
外科学 | 1572篇 |
综合类 | 329篇 |
一般理论 | 26篇 |
预防医学 | 1573篇 |
眼科学 | 479篇 |
药学 | 1126篇 |
中国医学 | 44篇 |
肿瘤学 | 1269篇 |
出版年
2023年 | 140篇 |
2022年 | 226篇 |
2021年 | 547篇 |
2020年 | 356篇 |
2019年 | 477篇 |
2018年 | 518篇 |
2017年 | 369篇 |
2016年 | 434篇 |
2015年 | 454篇 |
2014年 | 674篇 |
2013年 | 873篇 |
2012年 | 1232篇 |
2011年 | 1271篇 |
2010年 | 735篇 |
2009年 | 662篇 |
2008年 | 945篇 |
2007年 | 1061篇 |
2006年 | 914篇 |
2005年 | 880篇 |
2004年 | 808篇 |
2003年 | 744篇 |
2002年 | 676篇 |
2001年 | 193篇 |
2000年 | 169篇 |
1999年 | 183篇 |
1998年 | 139篇 |
1997年 | 110篇 |
1996年 | 102篇 |
1995年 | 99篇 |
1994年 | 90篇 |
1993年 | 82篇 |
1992年 | 111篇 |
1991年 | 121篇 |
1990年 | 122篇 |
1989年 | 100篇 |
1988年 | 91篇 |
1987年 | 101篇 |
1986年 | 76篇 |
1985年 | 94篇 |
1984年 | 85篇 |
1983年 | 66篇 |
1982年 | 90篇 |
1981年 | 94篇 |
1980年 | 88篇 |
1979年 | 72篇 |
1978年 | 56篇 |
1977年 | 45篇 |
1976年 | 43篇 |
1974年 | 32篇 |
1973年 | 40篇 |
排序方式: 共有10000条查询结果,搜索用时 687 毫秒
111.
R. S. Verma R. A. Conte M. J. Macera A. S. S. I. Khan S. Hebi A. A. Masoud A. Al Zaman M. Al Bader 《American journal of medical genetics. Part A》1993,46(1):104-108
A newborn infant was referred because of low-set ears, mild downward slant of the palpebral fissues, micrognathia with higharched palate, a flat midface, small mouth, and thin upper lip with cupid bow configuration. To some extent her cry resembled that associated with cri du chat syndrome. Cytogenetic findings with G- and Q-banding alone failed to characterize precisely the complex translocations. By the chromosome in situ suppression (CISS) hybridization technique using whole chromosome specific probes, a complex 4 breakpoint rearrangement involving both arms of a single chromosome 1 with the long arms of chromosome 5 and 11 was disclosed, i.e., 46,XX, der(1),t(1;5) t(1;11) (5qter→5q31::1p31.3→1q44::11q23→11qter;5pter→5q31::1p31.3→1pter;11pter→11q23::1q44→1qter). Gene deregulation and position effect may explain the multiple anomalies in individuals with apparently balanced translocations may shed some light towards unveiling the clinical consequences associated with aberrations which are presumably balanced. © 1993 Wiley-Liss, Inc. 相似文献
112.
Implications of urine pO2 for renal medullary blood flow 总被引:2,自引:0,他引:2
113.
Lack of PTEN expression in endometrial intraepithelial neoplasia is correlated with cancer progression 总被引:6,自引:0,他引:6
Baak JP Van Diermen B Steinbakk A Janssen E Skaland I Mutter GL Fiane B Løvslett K 《Human pathology》2005,36(5):555-561
We tested the hypothesis that PTEN inactivation may stratify cancer progression risk among putative endometrial hyperplasias, classified prognostically by means of the morphometric D score (DS). The DS, calculated from 3 morphometric variables measured in routine hematoxylin-eosin-stained endometrial biopsy slides, is the most sensitive and specific method of endometrial cancer risk prediction currently available. Clinical outcomes of 103 women with endometrial hyperplasia on biopsy were tallied according to the DS. Seven (7/103; 7%) patients with carcinoma during follow-up were all distributed within the high-risk prognostic group (ie, DS <1 = endometrial intraepithelial neoplasia [EIN]) (7/21; 33% progression). None of the 82 cases with a DS higher than 1 progressed. All cases that progressed were PTEN null, indicating that this genotype is capable of further stratifying cancer progression risk in hyperplasias irrespective of histological categorization. However, only 16% of the PTEN-null cases progressed. When PTEN expression pattern was combined with EIN, the prognostic power was greatly increased (specificity from 63% for PTEN and 85% for EIN to 93% when combined; positive predictive value from 16% and 33% to 50%). We conclude that loss of PTEN expression is the first biomarker in EIN that increases the accuracy of the prognostic DS to predict cancer progression risk. Unless endometrial hyperplasias are stratified by histological morphometric D-Score, PTEN has a low positive predictive value. 相似文献
114.
Mol A van Lieshout MI Dam-de Veen CG Neuenschwander S Hoerstrup SP Baaijens FP Bouten CV 《Biomaterials》2005,26(16):3113-3121
In cardiovascular tissue engineering approaches, efficient seeding methods are essential. To achieve this and to save time, cells can be encapsulated in gels. Combining the advantages of a gel as a cell carrier with the advantages of a fiber-based scaffold, providing structural integrity to the developing tissue, might offer several advantages. In this study, seeding by using fibrin as a cell carrier is compared to the conventional static seeding method with regard to tissue development. Seeding with fibrin resulted in less loss of soluble collagen into the medium and a more mature extracellular matrix in a shorter period of time. The use of fibrin degradation inhibitors was shown to inhibit extracellular matrix formation, although it did not hamper cell proliferation. The use of fibrin as a cell carrier to seed cells into a fiber-based scaffold may represent a promising, timesaving approach in cardiovascular tissue engineering applications. 相似文献
115.
The rel-associated pp40 protein prevents DNA binding of Rel and NF-kappa B: relationship with I kappa B beta and regulation by phosphorylation 总被引:71,自引:0,他引:71
L D Kerr J Inoue N Davis E Link P A Baeuerle H R Bose I M Verma 《Genes & development》1991,5(8):1464-1476
The product of proto-oncogene Rel associates with a number of cellular proteins. We have studied the effect of one of them, a phosphoprotein of 40 kD (pp40), on the DNA-binding activity of the Rel protein. We demonstrate that purified pp40 not only inhibits the binding of Rel, but also NF-kappa B (p50-p65) heterocomplex to DNA. Additionally, I kappa B beta, but not I kappa B alpha, also prevented the binding of Rel to the kappa B site. I kappa B beta and pp40 are related proteins because (1) they share a number of common tryptic peptides, (2) their inhibitory effect on DNA binding can be abolished by preincubation with pp40-specific antiserum, and (3) labeled I kappa B beta can be immunoprecipitated with pp40 antibodies. pp40 is part of the Rel complex present in the cytoplasm and nuclear extracts of WEHI-231 cells. The activity of pp40 to inhibit the DNA binding of Rel and NF-kappa B is modulated by phosphorylation. 相似文献
116.
Because published experiments documenting frequency-dependent sexual selection have exclusively used young virgins, we endeavored to test for this same phenomenon in females who differed in age and in previous mating experiences. Direct observation tests were conducted employingDrosophila pseudoobscura females of the previously described Arrowhead (AR) and Chiricahua (CH) homokaryotypes. Four-day-old virgin females confer mating advantages on all tested rare males, i.e.,or. AR, and CH. Females who had a previous mating experience when younger award a rare-male advantage only when the rare male is of the same genotype of karyotype as their first mate, and matings are random when the first-mate type males are common. Equivalently aged (11 days) virgin females mate significantly more than expected with minority males if they are of the same karyotype as the females themselves. whereas matings are near random when the males are different. Frequency-dependent mating, therefore, is both age and experience dependent.A. P. is supported by funds from the Biopsychology Program, Hunter College and C.U.N.Y. L.F. is the recipient of USPHS Career Award 2KO3 HD 0903308: work supported by NIH Grant 5RO1 18907-02.Paper presented at the third annual meeting of the Behavior Genetics Association, Chapel Hill, North Carolina, April 7, 1973. 相似文献
117.
Primary primitive neuroectodermal tumor of the cauda equina 总被引:5,自引:0,他引:5
Primitive neuroectodermal tumors (PNETs) are aggressive neoplasms composed predominantly of undifferentiated cells that show evidence of neural differentiation. Although their classification has been controversial, PNETs are well recognized primary tumors of both central and peripheral nervous systems. PNETs must be distinguished from other round-cell tumors, including Ewing's sarcoma, lymphoma, rhabdomyosarcoma, and small cell carcinoma. Intraspinal PNETs are rare neoplasms that are usually metastatic in origin. We describe the eighth reported primary PNET of the cauda equina that developed in a 52-year-old man with no significant medical history. The tumor was characterized by Homer-Wright rosettes and immunoreactivity for CD99, glial fibrillary acidic protein, neuron-specific enolase S100, and synaptophysin. The anatomic location of primary intrathecal PNETs is important as those arising in the spinal cord develop in the central nervous system, whereas those arising in the cauda equina develop in the peripheral nervous system. The histogenesis of intrathecal PNETs may be multifactorial. 相似文献
118.
119.
Pericentric inversion of chromosome 7 (inv(7) (p22q11.2)) and ring chromosome 8 (r(8) (p23q24.3)) in a girl with minor anomalies.
下载免费PDF全文
![点击此处可从《Journal of medical genetics》网站下载免费的PDF全文](/ch/ext_images/free.gif)
A 13 year old girl was referred with congenital microcephaly, developmental delay, a prominent nose, highly arched palate, and an apparently low set left ear. She was found to have a pericentric inversion of one chromosome 7 and a ring chromosome 8, 46,XX,inv(7) (pter----p22::q11.23----p22::q11.23----qter), r(8) (p23q24.3). The concurrence of these two abnormalities is a rare event and has not been reported previously. 相似文献
120.
We report here that human T lymphocytes have the capacity of acquiring large amounts of MHC class II molecules from various types of antigen-presenting cells (APC) in an antigen-independent manner. The transfer of MHC class II molecules from APC to T cell required direct cell-to-cell contact and appeared to involve the interaction of numerous adhesion molecules between these cells. Depletion of cholesterol from the plasma membrane reduced the amount of MHC class II transferred onto the T cells. Most significantly, the newly acquired MHC class II molecules were capable of efficiently presenting antigen to T helper cells. These results suggest that T cells are able to interact with other T cells to regulate immune responses by presenting MHC peptide complexes that have been snatched away from nearby APC. 相似文献