全文获取类型
收费全文 | 6871篇 |
免费 | 484篇 |
国内免费 | 16篇 |
专业分类
耳鼻咽喉 | 59篇 |
儿科学 | 168篇 |
妇产科学 | 130篇 |
基础医学 | 1211篇 |
口腔科学 | 128篇 |
临床医学 | 679篇 |
内科学 | 1445篇 |
皮肤病学 | 152篇 |
神经病学 | 653篇 |
特种医学 | 297篇 |
外国民族医学 | 17篇 |
外科学 | 693篇 |
综合类 | 34篇 |
一般理论 | 8篇 |
预防医学 | 569篇 |
眼科学 | 105篇 |
药学 | 480篇 |
中国医学 | 13篇 |
肿瘤学 | 530篇 |
出版年
2024年 | 8篇 |
2023年 | 58篇 |
2022年 | 31篇 |
2021年 | 111篇 |
2020年 | 88篇 |
2019年 | 125篇 |
2018年 | 261篇 |
2017年 | 180篇 |
2016年 | 180篇 |
2015年 | 226篇 |
2014年 | 222篇 |
2013年 | 293篇 |
2012年 | 583篇 |
2011年 | 617篇 |
2010年 | 279篇 |
2009年 | 244篇 |
2008年 | 478篇 |
2007年 | 627篇 |
2006年 | 534篇 |
2005年 | 545篇 |
2004年 | 453篇 |
2003年 | 432篇 |
2002年 | 370篇 |
2001年 | 42篇 |
2000年 | 44篇 |
1999年 | 48篇 |
1998年 | 23篇 |
1997年 | 14篇 |
1996年 | 11篇 |
1995年 | 11篇 |
1994年 | 10篇 |
1993年 | 9篇 |
1992年 | 23篇 |
1991年 | 26篇 |
1990年 | 13篇 |
1989年 | 11篇 |
1988年 | 8篇 |
1987年 | 6篇 |
1986年 | 8篇 |
1985年 | 7篇 |
1984年 | 7篇 |
1983年 | 10篇 |
1974年 | 6篇 |
1973年 | 11篇 |
1972年 | 9篇 |
1970年 | 5篇 |
1969年 | 6篇 |
1968年 | 5篇 |
1967年 | 11篇 |
1966年 | 5篇 |
排序方式: 共有7371条查询结果,搜索用时 15 毫秒
21.
22.
Summary We have analyzed the expression and function of the intron-encoded bI4 maturase when frame-shift mutations in the upstream exon alter the translational process. By constructing secondary cis-acting mutations within the b14 intron, we observed (1) that the bI4 maturase is still translated in the presence of the upstream mutation, albeit in very low amounts, and (2) that the limited amounts of bI4 maturase made under these conditions is no longer able to promote the splicing process of the aI4 intron. These observations, which further strengthen the maturase model, strongly suggest that bI4 maturase acts sequentially on the bI4 intron and then on the aI4 intron. 相似文献
23.
Lafay-Cousin L Soenen V Mazingue F Preudhomme C Laï JL Andrieux J 《Cancer Genetics and Cytogenetics》2004,150(2):153-155
Recurrent chromosomal rearrangements involving the 11q23 region have been described in various hematologic malignancies. Among these rearrangements, translocations are the most common mechanism involving the mixed lineage leukemia gene (MLL). Few cases of insertion have been reported and, to our knowledge, none of them involved MLL and chromosome 1. We report a complex karyotype in a childhood acute myelomonocytic leukemia (AML M4) involving the 11q23 region with an insertion between chromosomes 1 and 11 in addition to a translocation between chromosomes 11 and 22. This translocation was clarified by fluorescence in situ hybridization (FISH) analysis: 46,XY,ins(1;11)(q22q23;q13q23),t(11;22)(q13;q11q12). This finding also underlines the complementary contribution of conventional cytogenetic and FISH analysis to detect karyotypic complex abnormalities. 相似文献
24.
Liver extracellular matrix in health and disease 总被引:13,自引:0,他引:13
Liver fibrosis is the hallmark of every chronic liver disease. It is also the major factor of morbidity and mortality due to the development of cirrhosis and its complications including hepatocellular carcinoma. But even at the beginning of the process of liver fibrosis and due to the strategic position of the extracellular matrix at the interface between blood flow and epithelial compartment, any quantitative or qualitative modification of extracellular matrix will rapidly affect structure and function of the liver. The development of several animal models of liver fibrosis as well as isolation and cultivation of hepatic stellate cells, the major fibrogenic cell type in the liver, led to the gathering of recent knowledge on the mechanism of liver fibrosis. Activation of hepatic stellate cells is a key event in this process and many details on this finely tuned mechanism are now available. In addition to these experimental data, experience from chronic hepatitis C now allows the development of new concepts and perspectives such as liver fibrosis regression and antifibrotic therapies. 相似文献
25.
Morel F Gallon F Amice V Le Bris MJ Le Martelot MT Roche S Valéri A Derrien V Herry A Amice J De Braekeleer M 《Human reproduction (Oxford, England)》2002,17(10):2552-2555
BACKGROUND: Several studies have shown an increased frequency of constitutional chromosome aberrations in male and female partners of couples examined prior to ICSI. We conducted a cohort study to determine whether there was an increase in numerical sex chromosome mosaicism among couples undergoing ICSI compared with fertile couples. METHODS: Cytogenetic investigations were performed in 228 females and 208 males seen for ICSI between January 1997 and March 2001. They were matched to control females and males. RESULTS: Sex chromosome loss or gain was observed in at least one cell from 24.1% of ICSI women in comparison with 22% of controls (not significant). A significant difference between these two groups was found when X chromosome loss in at least two cells was considered, 9.6% for ICSI females versus 4.8% for controls (P = 0.01). No significant difference was observed between male groups concerning loss or gain of the X or Y chromosome. CONCLUSION: Our results support previously published studies indicating that the loss of an X chromosome in a single cell in females undergoing ICSI is probably an artefact. However, they suggest that a woman could have true sex chromosome mosaicism when two 45,X0 cells are found. 相似文献
26.
Maturity-onset diabetes of the young (MODY) is a subtype of early-onset diabetes mellitus which is characterized by autosomal dominant inheritance. Several genes are known to induce MODY : HNF4A/MODY1, GCK/MODY2, TCF1/MODY3, IPF1/MODY4, TCF2/MODY5 and NEUROD1/MODY6. We studied a Swiss family with 13 diabetic patients over 3 generations. The average age at diagnosis was 35 +/- 15 years (7 subjects before 30). In addition, 2 individuals had an abnormal oral glucose tolerance. The mutation present in this family was located in the DNA binding domain of HNF4A, a strongly conserved region across almost all species, and segregated in all the MODY patients. Identification of this missense mutation allowed for presymptomatic diagnosis in the younger generations and will improve medical follow-up of the predisposed individuals. 相似文献
27.
María Francisca Garijo José Fernando Val‐Bernal Alfonso Vega Daniel Val 《Pathology international》2008,58(12):787-791
Despite the frequent use of fine‐needle aspiration, core biopsy and surgery, postoperative spindle cell nodule (PSCN) is a rare pathological complication that may be diagnostically treacherous. Presented herein is the case of a 52‐year‐old woman who developed a 7 mm mammary nodular lesion 66 days after removal of an area of columnar cell hyperplasia involving cellular and architectural atypia, performed with the Mammotome Breast Biopsy System. The lesion was highly cellular and composed of intersecting fascicles of plump spindle cells with blunt‐ended elongated nuclei and nucleoli easily visible. Interspersed mononuclear cells and hemosiderin‐laden macrophages were evident. PSCN is a reactive, benign myofibroblastic proliferation. Differential diagnosis includes benign and malignant spindle cell lesions of the breast. Recognition of this reactive lesion will avoid overdiagnosis of spindle cell malignant tumor. Attention to clinicopathological and histological features should result in accurate recognition of this lesion. 相似文献
28.
Ekouevi DK Rouet F Becquet R Inwoley A Viho I Tonwe-Gold B Bequet L Dabis F Leroy V;ANRS / Ditrame Plus Study Group 《Journal of acquired immune deficiency syndromes (1999)》2004,36(2):755-757
The aim of this study performed in Abidjan, C?te d'Ivoire, was to describe the distribution of CD4+ T-cell lymphocytes (CD4) in HIV-1-infected (HIV+) pregnant women diagnosed during prenatal voluntary counseling and testing and to assess whether HIV-related immunodeficiency influenced the acceptance of an antiretroviral (ARV) package (zidovudine beginning at 36 weeks of amenorrhea plus intrapartum nevirapine) to prevent mother-to-child transmission. Between April and June 2002, a CD4 count was systematically performed in all HIV+ women (n=221) in 5 antenatal clinics carrying out voluntary counseling and testing. No difference in CD4 count was found in HIV+ women who did not return for their test result (n=50) and those who were informed of their positive serostatus (n=171) (median CD4 count: 389/mm3 vs. 420/mm3; P=0.19). We also found a lack of difference in CD4 count in those who accepted ARV (n=72) and those who did not but knew their HIV status (n=99) (median CD4 count: 405/mm3 vs. 425/mm3; P=0.47). The overall uptake of the intervention (31.9%) appeared to be independent of the maternal immune status. 相似文献
29.
Baujat G Rio M Rossignol S Sanlaville D Lyonnet S Le Merrer M Munnich A Gicquel C Colleaux L Cormier-Daire V 《American journal of medical genetics. Part C, Seminars in medical genetics》2005,(1):4-11
Here, we report the clinical and molecular analysis of 75 patients with overgrowth and mental retardation, including 45 previously reported cases [Rio et al., 2003; Baujat et al., 2004]. Two groups are distinguished: group I corresponding to patients with recognizable overgrowth syndromes (Sotos syndrome (SS), Weaver syndrome (WS), Beckwith-Wiedemann syndrome, Simpson-Golabi-Behmel syndrome (SGBS), and del(22)(qter) syndrome) (60 cases) and group II corresponding to unclassified cases (15 patients). We investigated NSD1 and GPC3 deletions or mutations, 11p15 abnormalities, and 22qter deletions. Surprisingly, in Group I, two SS patients had 11p15 abnormalities and two patients with Beckwith-Wiedemann syndrome had NSD1 aberrations. In group II, two cases of del(22)(qter) were identified but neither NSD1, 11p15, nor GPC3 abnormalities were detected. These results emphasize the clinical and molecular overlap in overgrowth conditions. 相似文献
30.
Sensory relay structures in the spinal cord dorsal horn are now thought to be active processing structures that function before supraspinal sensory integration. Dorsal horn neurons directly receive nociceptive (pain) signals from the periphery, express a high degree of functional plasticity and are involved in long-term sensitization and chronic pain. We show here that deep dorsal horn neurons (DHNs) in Wistar rats can switch their intrinsic firing properties from tonic to plateau or endogenous bursting patterns, depending upon the balance of control by metabotropic glutamate (mGlu) and GABA(B) receptors. We further show that this modulation acts on at least one common target, the inwardly rectifying potassium channel (Kir3). Finally, we found that these firing modes correspond to specific functional states of information transfer in which dorsal horn neurons can faithfully transmit, greatly enhance or block the transfer of nociceptive information. 相似文献