全文获取类型
收费全文 | 228744篇 |
免费 | 4505篇 |
国内免费 | 110篇 |
专业分类
耳鼻咽喉 | 1651篇 |
儿科学 | 8870篇 |
妇产科学 | 4492篇 |
基础医学 | 23242篇 |
口腔科学 | 2073篇 |
临床医学 | 20746篇 |
内科学 | 39837篇 |
皮肤病学 | 1405篇 |
神经病学 | 21573篇 |
特种医学 | 9837篇 |
外科学 | 33213篇 |
综合类 | 2891篇 |
一般理论 | 109篇 |
预防医学 | 25507篇 |
眼科学 | 3475篇 |
药学 | 12974篇 |
中国医学 | 686篇 |
肿瘤学 | 20778篇 |
出版年
2023年 | 273篇 |
2022年 | 376篇 |
2021年 | 1029篇 |
2020年 | 705篇 |
2019年 | 1067篇 |
2018年 | 22954篇 |
2017年 | 18183篇 |
2016年 | 20427篇 |
2015年 | 2126篇 |
2014年 | 2478篇 |
2013年 | 3457篇 |
2012年 | 10798篇 |
2011年 | 25014篇 |
2010年 | 20950篇 |
2009年 | 13528篇 |
2008年 | 23087篇 |
2007年 | 25533篇 |
2006年 | 4398篇 |
2005年 | 6138篇 |
2004年 | 7147篇 |
2003年 | 7886篇 |
2002年 | 5762篇 |
2001年 | 744篇 |
2000年 | 751篇 |
1999年 | 640篇 |
1998年 | 883篇 |
1997年 | 807篇 |
1996年 | 566篇 |
1995年 | 580篇 |
1994年 | 520篇 |
1993年 | 395篇 |
1992年 | 282篇 |
1991年 | 299篇 |
1990年 | 315篇 |
1989年 | 280篇 |
1988年 | 241篇 |
1987年 | 221篇 |
1986年 | 195篇 |
1985年 | 201篇 |
1984年 | 212篇 |
1983年 | 189篇 |
1982年 | 240篇 |
1981年 | 210篇 |
1980年 | 194篇 |
1979年 | 98篇 |
1978年 | 125篇 |
1977年 | 59篇 |
1976年 | 69篇 |
1974年 | 87篇 |
1938年 | 60篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
991.
X-linked mixed deafness (DFN3): cloning and characterization of the critical region allows the identification of novel microdeletions 总被引:5,自引:0,他引:5
Huber Irene; Bitner-Gllndzicz Maria; de Kok Yvette J.M.; van der Maarel Silvere M.; Ishikawa-Brush Yumiko; Monaco Anthony P.; Robinson David; Malcolm Susan; Pembrey Marcus E.; Brunner Han G.; Cremers Frans P.M.; Ropers Hans-Hilger 《Human molecular genetics》1994,3(7):1151-1154
We have found that the microsatellite marker AFM207zg5 (DXS995)maps to all previously described deletions which are associatedwith X-linked mixed deafness (DFN3) with or without choroideremiaand mental retardation. Employing this marker and pHU16 (DXS26)we have identified two partially overlapping yeast artificialchromosome clones which were used to construct a complete 850kb cosmid contig. Cosmids from this contig have been testedby Southern blot analysis on DNA from 16 unrelated males withX-linked deafness. Two novel microdeletions were detected inpatients which exhibit the characteristic DFN3 phenotype. Bothdeletions are completely contained within one of the known DFN3-deletions,but one of them does not overlap with two previously describeddeletions in patients with contiguous gene syndromes consistingof DFN3, chorolderemia, and mental retardation. Assuming thatonly a single gene is involved, this suggests that the DFN3gene spans a chromosomal region of at least 400 kb. 相似文献
992.
The E6–AP Ubiquitin–Protein Ligase (UBE3A) Gene Is Localized within a Narrowed Angelman Syndrome Critical Region
下载免费PDF全文
![点击此处可从《Genome research》网站下载免费的PDF全文](/ch/ext_images/free.gif)
993.
Waldemar Pruzanski Susan Saito Mahboob Alam Narendranath S. Ranadive 《Inflammation》1988,12(1):99-106
Cationic fraction III from the lysosomes of normal human peripheral blood polymorphonuclear cells (PMNs) was found to contain superoxide generation enhancing protein (SGEP). Herein, we report on the influence of partially purified SGEP obtained from fraction III (subfractions III-5 and III-6), on various phagocytic functions of human PMNs. SGEP markedly enhanced intracellular bactericidal activity of human peripheral PMNs. The enhancement was time and dose dependent. It also reduced adhesiveness of the PMNs. SGEP did not influence chemotaxis, phagocytosis or phagocytic index. These findings are compatible with our original observation regarding superoxide generation enhancement properties of SGEP. 相似文献
994.
995.
Three influenza viruses, A/Puerto Rico/8/34-A/England/939/69 clone 7a (H3N2), A/Fiji/15899/83 (H1N1), and A/Victoria/3/75 (H3N2), induce different levels of apoptosis in vitro at equal moi; Clone 7a > A/Victoria > A/Fiji. Previous studies have shown that several viral proteins from clone 7a and A/Fiji, including PB2, NA, NS1, M1, and M2, induce apoptosis when expressed individually fused to the herpes simplex virus tegument protein, VP22. However, this did not reflect viral protein-protein-RNA interactions known to occur within infected cells. To explore the role of viral proteins in apoptosis under infection conditions, recombinant viruses with single or triple gene exchanges were generated using A/Victoria or clone 7a as the background virus. Inserting the A/Fiji NS or PB2 gene into A/Victoria or clone 7a significantly reduced the level of apoptosis compared to the parent virus while clone 7a PA or NP genes increased apoptosis. Inserting A/Fiji NA or HA or clone 7a NS, M, NA, or HA genes individually into A/Victoria had no significant effect on apoptosis. Surprisingly, inserting the M, NA, and HA genes of A/Fiji together into clone 7a reduced apoptosis, whereas inserting clone 7a M, NA, and HA together into A/Fiji increased apoptosis. These results suggest that no single virus protein induces apoptosis and that the combination of genes required may be strain specific, highlighting the difficulty of predicting the virulence of new strains that arise in nature. No support for the view that apoptosis is essential for high virus yields was obtained as high virus yields were obtained with viruses that induced both high and low levels of apoptosis. 相似文献
996.
Huh WK Oono T Shirafuji Y Akiyama H Arata J Sakaguchi M Huh NH Iwatsuki K 《Journal of molecular medicine (Berlin, Germany)》2002,80(10):678-684
Defensins are cationic antimicrobial peptides with a broad spectrum. Recently human beta-defensin 2 (hBD-2) has been isolated from psoriatic skin; however, its exact localization and fate have not been fully understood. We studied the distribution pattern of hBD-2 in skin tissues of psoriasis and other inflammatory skin diseases. In the upper spinous and granular layer of psoriasis vulgaris hBD-2 was present in the cytoplasm. In the horny layer the positive signals were in a basket-weave pattern, indicating possible accumulation of hBD-2 in the intercellular space. The similar pattern of hBD-2 distribution was observed in the lesions of nummular eczema and atopic dermatitis. hBD-2 was not detected in the section of normal elbow and knee skin. When isolated psoriatic scales were stained, hBD-2 was detected in a wrapping paper-like distribution pattern surrounding the corneocytes. In horny layer of psoriatic skin hBD-2 was closely associated or colocalized with elafin, which is known to be in extracellular space, as demonstrated by double staining. Western blot analysis using cultured human keratinocytes detected hBD-2 with an expected size in the conditioned medium and in the cell lysates when stimulated with 5% FCS or IL-alpha. These results indicate that hBD-2 was synthesized and remained in cytoplasm in the upper spinous and granular layer, and then secreted into intercellular space in the horny layer. This dynamic change in hBD-2 distribution in epidermis is certainly relevant to function as an innate host defense mechanism against invading micro-organisms. 相似文献
997.
Theodore Kushnick Thomas G. Irons John E. Wiley Elizabeth A. Gettig Kathleen W. Rao Susan Bowyer John M. Opitz James F. Reynolds 《American journal of medical genetics. Part A》1987,28(3):567-574
Two white females, age 2 1/2 and 33 years, respectively, were investigated because of severe mental retardation associated with neurologic abnormalities, coarse face, and soft tissue syndactyly involving upper and lower limbs. Each had cytogenetic findings of a mosaic variant of Ullrich-Turner syndrome with X ring chromosome in peripheral lymphocyte and skin fibroblasts. Early X replication occurred in one-third of the X ring chromosomes; there was no evidence for X-autosome translocation involving either X and an autosomal duplication; results of studies for fragility of the X chromosomes were unremarkable. In situ hybridization with an X centromere probe was positive for the ring. To our knowledge, the unusual constellation of cytogenetic, physical, and mental findings seen in these 2 individuals has not been reported previously. 相似文献
998.
999.
1000.
Paul B. Samollow Nicolas Gouin Pat Miethke Susan M. Mahaney Margaret Kenney John L. VandeBerg Jennifer A. Marshall Graves Candace M. Kammerer 《Chromosome research》2007,15(3):269-282
The genome of the gray, short-tailed opossum, Monodelphis domestica, will be the first of any marsupial to be fully sequenced. The utility of this sequence will be greatly enhanced by construction
and integration of detailed genetic and physical maps. Therefore, it is important to verify the unusual recombinational characteristics
that were suggested by the ‘first-generation’ M. domestica linkage map; specifically, very low levels of recombination and severely reduced female recombination, both of which are
contrary to patterns in other vertebrates. We constructed a new linkage map based on a different genetic cross, using a new
and much larger set of map markers, and physically anchored and oriented the linkage groups onto chromosomes via fluorescence
in-situ hybridization mapping. This map includes 150 loci in eight autosomal linkage groups corresponding to the eight autosome pairs,
and spans 86–89% of the autosomal genome. The sex-averaged autosomal map covers 715 cM, with a full-length estimate of 866 cM;
the shortest full-length linkage map reported for any vertebrate. The sex-specific maps confirmed severely reduced female
recombination in all linkage groups, and an overall F/M map ratio = 0.54. These results greatly extend earlier findings,
and provide an improved microsatellite-based linkage map for this species.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献