全文获取类型
收费全文 | 3119篇 |
免费 | 150篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 50篇 |
儿科学 | 148篇 |
妇产科学 | 42篇 |
基础医学 | 451篇 |
口腔科学 | 45篇 |
临床医学 | 233篇 |
内科学 | 753篇 |
皮肤病学 | 90篇 |
神经病学 | 204篇 |
特种医学 | 62篇 |
外科学 | 471篇 |
综合类 | 106篇 |
预防医学 | 155篇 |
眼科学 | 86篇 |
药学 | 175篇 |
中国医学 | 7篇 |
肿瘤学 | 199篇 |
出版年
2023年 | 34篇 |
2022年 | 43篇 |
2021年 | 122篇 |
2020年 | 67篇 |
2019年 | 76篇 |
2018年 | 93篇 |
2017年 | 73篇 |
2016年 | 106篇 |
2015年 | 108篇 |
2014年 | 132篇 |
2013年 | 142篇 |
2012年 | 227篇 |
2011年 | 203篇 |
2010年 | 119篇 |
2009年 | 107篇 |
2008年 | 170篇 |
2007年 | 167篇 |
2006年 | 147篇 |
2005年 | 159篇 |
2004年 | 162篇 |
2003年 | 160篇 |
2002年 | 117篇 |
2001年 | 70篇 |
2000年 | 55篇 |
1999年 | 57篇 |
1998年 | 31篇 |
1997年 | 24篇 |
1996年 | 16篇 |
1995年 | 20篇 |
1993年 | 8篇 |
1992年 | 16篇 |
1991年 | 27篇 |
1990年 | 22篇 |
1989年 | 18篇 |
1988年 | 10篇 |
1987年 | 18篇 |
1986年 | 16篇 |
1985年 | 17篇 |
1984年 | 12篇 |
1982年 | 8篇 |
1981年 | 5篇 |
1980年 | 6篇 |
1979年 | 12篇 |
1978年 | 5篇 |
1977年 | 5篇 |
1976年 | 6篇 |
1974年 | 6篇 |
1971年 | 5篇 |
1970年 | 7篇 |
1945年 | 5篇 |
排序方式: 共有3277条查询结果,搜索用时 140 毫秒
1.
2.
Isolation of Stomatococcus mucilaginosus from drug user with endocarditis. 总被引:4,自引:4,他引:0 下载免费PDF全文
P E Coudron S M Markowitz L B Mohanty P F Schatzki J M Payne 《Journal of clinical microbiology》1987,25(8):1359-1363
Stomatococcus mucilaginosus was isolated from the blood of a patient with endocarditis and a past history of drug abuse and aortic valve replacement. At autopsy, Gram stain of the aortic valve revealed gram-positive cocci. Our isolate was atypical for S. mucilaginosus in that colonies were nonmucoid and nonadherent to agar surfaces. Cellular capsules were demonstrated by light and electron microscopy. Phenotypic characteristics identified by conventional methods as well as profile numbers obtained by using two commercial identification systems for staphylococci, the API Staph-Ident and the dms Staph Trac, are presented. Practical tests that differentiate S. mucilaginosus from the genera Micrococcus and Staphylococcus include growth on nutrient agar containing salt and lysostaphin susceptibility. Additional tests that helped differentiate our isolate from group D streptococci included hydrolysis of L-pyrrolidonyl-beta-naphthylamide and streptococcal serogrouping. 相似文献
3.
Nand L. Sharma Vikram K. Mahajan Neelam Gupta Nitin Ranjan and Anju Lath 《Journal of cutaneous pathology》2009,36(4):486-492
Ehlers-Danlos syndrome – vascular type, the only lethal form, is rarely reported in dermatology literature. It is characterized by translucent, atrophic skin, easy bruising, arterial, intestinal and/or uterine fragility manifesting as varicose veins, aneurysms and vascular/visceral/uterine rupture. As its dermatopathologic features are not well elucidated, diagnosis is often made after a catastrophic complication or at autopsy. This 36 year-old non-consanguineous male had brown-black plaques with atrophy and frequent ulceration over legs and dorsal feet and tortuous varicose veins around ankles for the past 15 years. Perivenous skin was translucent and hypopigmented. He had multiple and ecchymotic keloids and small atrophic, pityriasis versicolor-like lesions over trunk. He did not have hypermobile/hyperextensible skin and joints and showed no systemic or investigative abnormality. Histopathologic features of atrophic lesion included blood extravasation in atrophic epidermis/dermis, focal clustering and dilatation of blood vessels, malformed vessel walls, abundant hemosiderin in the dermis and homogenously stained/whorled patterned collagen especially around blood vessels. Pathology of keloidal lesion showed new collagen and vascular fragility. These histopathologic features appear of diagnostic value especially in patients who have compatible clinical findings but cannot afford confirmation by biochemical testing for abnormal synthesis of type III procollagen or identification of mutations in the COL3A1 gene. 相似文献
4.
A. Ravikumar S. Mohanty R. P. Vatsanath S. Raghunandhan 《Indian journal of otolaryngology and head and neck surgery》2004,56(4):317-320
The co-existence of fungal elements in allergic nasal Polyposis, has given rise to a distinct clinical entity known as ‘Allergic
fungal sinusitis ’ (AF’S). Many a time, these fungal elements may not be diagnosed pre-operatively by routine diagnostic nasal
endoscopy or CT scan of paranasal sinuses, due to the florid presentation of nasal polyps, which usually obscure the underlying
fungal pathology. The diagnosis is often made intra-operatively. The post-operative confirmation of AFS is by histopathology,
fungal smear, fungal culture, allergic murin study and fungal specific IgE titres. We report a series often such cases done
in our institution, which highlight that AFS should be considered as a differential diagnosis in Sinonasal Polyposis cases,
for their effective management. 相似文献
5.
A. Satish Chandra Sanjeev Mohanty 《Indian journal of otolaryngology and head and neck surgery》2007,59(1):43-44
Role of Embolisation in preoperative management of Nasopharyngeal angiofibroma is well established in present day therapeutic
modalities. An improvised technique i.e., subselective embolisation has been provided by Interventional radiologists to fortify
the therapeutic results. This study compares the final outcome of seven cases, four of which were embolised pre operatively.
Each case was dealt with varying surgical approaches. 相似文献
6.
7.
An out line of the scheme of training specialists in Otorhinolaryngology-Head and Neck Surgery (ORL-HNS) in South Africa is
given and the difference with Indian training discussed 相似文献
8.
Enhancement of cisplatin sensitivity of cisplatin-resistant human cervical carcinoma cells by bryostatin 1. 总被引:2,自引:0,他引:2
PURPOSE: Bryostatin 1, a unique protein kinase C (PKC) activator, is already in the clinical trials. An understanding of complex regulation of PKC by bryostatin 1 is essential for effective use of bryostatin 1 in the clinic. We have previously shown that the ability of bryostatin 1 to enhance cisplatin sensitivity correlated with its ability to down-regulate PKCdelta in HeLa cells. We have investigated how bryostatin 1 influences PKCdelta regulation in cisplatin-resistant HeLa (HeLa/CP) cells, and if bryostatin 1 could be used to reverse cisplatin resistance. EXPERIMENTAL DESIGN: Phorbol 12,13-dibutyrate (PDBu), bryostatin 1, and small interfering RNA were used to manipulate PKC level/activation status. Cell death was monitored by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, Annexin V dye-binding assay, and analysis of hypodiploid peak in a flow cytometer. RESULTS: Bryostatin 1 elicited a biphasic concentration response on PKCdelta down-regulation and cisplatin-induced cell death in HeLa/CP cells; the maximum effect was achieved with 1 nmol/L bryostatin 1. Down-regulation of PKCalpha increased with increasing concentrations of bryostatin 1. PDBu induced down-regulation of PKCalpha in HeLa and HeLa/CP cells but it had little effect on PKCdelta down-regulation in HeLa/CP cells. However, both PDBu and bryostatin 1 enhanced the sensitivity of HeLa/CP cells to cisplatin. Knockdown of PKCdelta by small interfering RNA inhibited cisplatin-induced apoptosis but knockdown of PKCalpha enhanced cisplatin-induced cell death. CONCLUSIONS: These results suggest that although PKCdelta acts as a proapoptotic protein, full-length PKCdelta may inhibit cisplatin-induced cell death. Thus, persistent activation/down-regulation of PKCdelta by bryostatin 1 was associated with cisplatin sensitization. Furthermore, PKCalpha acts as an antiapoptotic protein and down-regulation of PKCalpha by PDBu was associated with cellular sensitization to cisplatin. 相似文献
9.
Regulation of immunoglobulin heavy-chain gene rearrangements 总被引:1,自引:0,他引:1
Summary: Regulated assembly of antigen receptor gene segments to produce functional genes is a hallmark of B‐ and T‐lymphocyte development. The immunoglobulin heavy‐chain (IgH) and T‐cell receptor β‐chain genes rearrange first in B and T lineages, respectively. Both loci require two recombination events to assemble functional genes; D‐to‐J recombination occurs first followed by V‐to‐DJ recombination. Despite similarities in overall rearrangement patterns, each locus has unique regulatory features. Here, we review the characteristics of IgH gene rearrangements such as developmental timing, deletion versus inversion, DH gene segment utilization, ordered recombination of VH gene segments, and feedback inhibition of rearrangement in pre‐B cells. We summarize chromatin structural features of the locus before and during recombination and, wherever possible, incorporate these into working hypotheses for understanding regulation of IgH gene recombination. The picture emerges that the IgH locus is activated in discrete, independently regulated domains. A domain encompassing DH and JH gene segments is activated first, within which recombination is initiated. VH genes are activated subsequently and, in part, by interleukin‐7. These observations lead to a model for feedback inhibition of IgH rearrangements. 相似文献
10.