全文获取类型
收费全文 | 2120篇 |
免费 | 208篇 |
国内免费 | 28篇 |
专业分类
耳鼻咽喉 | 9篇 |
儿科学 | 173篇 |
妇产科学 | 34篇 |
基础医学 | 265篇 |
口腔科学 | 92篇 |
临床医学 | 213篇 |
内科学 | 409篇 |
皮肤病学 | 60篇 |
神经病学 | 69篇 |
特种医学 | 197篇 |
外科学 | 377篇 |
综合类 | 71篇 |
预防医学 | 151篇 |
眼科学 | 41篇 |
药学 | 84篇 |
中国医学 | 2篇 |
肿瘤学 | 109篇 |
出版年
2023年 | 17篇 |
2022年 | 12篇 |
2021年 | 20篇 |
2020年 | 24篇 |
2019年 | 17篇 |
2018年 | 62篇 |
2017年 | 50篇 |
2016年 | 49篇 |
2015年 | 65篇 |
2014年 | 88篇 |
2013年 | 127篇 |
2012年 | 70篇 |
2011年 | 60篇 |
2010年 | 103篇 |
2009年 | 110篇 |
2008年 | 61篇 |
2007年 | 81篇 |
2006年 | 83篇 |
2005年 | 50篇 |
2004年 | 49篇 |
2003年 | 36篇 |
2002年 | 40篇 |
2001年 | 27篇 |
2000年 | 34篇 |
1999年 | 42篇 |
1998年 | 109篇 |
1997年 | 97篇 |
1996年 | 117篇 |
1995年 | 73篇 |
1994年 | 87篇 |
1993年 | 45篇 |
1992年 | 32篇 |
1991年 | 32篇 |
1990年 | 22篇 |
1989年 | 43篇 |
1988年 | 42篇 |
1987年 | 42篇 |
1986年 | 37篇 |
1985年 | 36篇 |
1984年 | 21篇 |
1983年 | 20篇 |
1982年 | 27篇 |
1981年 | 18篇 |
1980年 | 19篇 |
1979年 | 7篇 |
1978年 | 8篇 |
1977年 | 11篇 |
1976年 | 16篇 |
1975年 | 9篇 |
1969年 | 2篇 |
排序方式: 共有2356条查询结果,搜索用时 15 毫秒
81.
82.
Monika Oláhová Tobias B Haack Charlotte L Alston Jessica AC Houghton Langping He Andrew AM Morris Garry K Brown Robert McFarland Zofia MA Chrzanowska-Lightowlers Robert N Lightowlers Holger Prokisch Robert W Taylor 《European journal of human genetics : EJHG》2015,23(7):935-939
Isolated mitochondrial complex IV (cytochrome c oxidase) deficiency is an important cause of mitochondrial disease in children and adults. It is genetically heterogeneous, given that both mtDNA-encoded and nuclear-encoded gene products contribute to structural components and assembly factors. Pathogenic variants within these proteins are associated with clinical variability ranging from isolated organ involvement to multisystem disease presentations. Defects in more than 10 complex IV assembly factors have been described including a recent Lebanese founder mutation in PET100 in patients presenting with Leigh syndrome. We report the clinical and molecular investigation of a patient with a fatal, neonatal-onset isolated complex IV deficiency associated with multiorgan involvement born to consanguineous, first-cousin British Asian parents. Exome sequencing revealed a homozygous truncating variant (c.142C>T, p.(Gln48*)) in the PET100 gene that results in a complete loss of enzyme activity and assembly of the holocomplex. Our report confirms PET100 mutation as an important cause of isolated complex IV deficiency outside of the Lebanese population, extending the phenotypic spectrum associated with abnormalities within this gene. 相似文献
83.
Monocytoid B-cell lymphoma: its evolution and relationship to other low- grade B-cell neoplasms 总被引:3,自引:0,他引:3
Monocytoid B-cell lymphoma (MBCL) is a newly recognized B-cell neoplasm of uncertain histogenesis. The cytologic features of the neoplastic monocytoid B lymphocytes are virtually identical to those of hairy cell leukemia (HCL). As with HCL, progression of MBCL to a higher histologic grade is very unusual. However, whereas circulating leukemic cells are a characteristic feature of HCL, peripheral blood involvement has not been reported in MBCL. We recently studied a patient with MBCL of the spleen and axillary lymph nodes who developed peripheral blood involvement by MBCL cells. Unlike the cells of HCL, the circulating MBCL cells exhibited strong acid phosphatase activity that was tartrate sensitive. The leukemic cells had the antigenic phenotype IgM lambda, CD20+, CD11c+, CD5-, CD25(TAC)-, and PCA-1-. Immunogenetic studies of both lymph node and peripheral blood cells revealed identical immunoglobulin heavy-chain gene rearrangements. When compared with a series of HCL, the immunophenotype was similar except for the absence of PCA-1 and TAC. Progression of the MBCL to a large cell lymphoma, also expressing IgM lambda, was documented in an abdominal lymph node of this patient. Therefore, although rare, peripheral blood involvement by lymphoma cells may occur during the course of MBCL and should be distinguished from HCL with cytochemical and immunophenotypic studies. In addition, comparison of the clinical, pathologic, and immunologic features of MBCL with those of other low-grade B-cell neoplasms suggests that a close lineage relationship exists between MBCL and HCL. 相似文献
84.
Hematopoietic growth factors (HGFs) interleukin-3 (IL-3) and granulocyte-macrophage colony-stimulating factor (GM-CSF) individually have been shown to increase the percentage of acute myeloid leukemia (AML) blasts in S phase and enhance the cytotoxic effects of Ara-C against these blasts in culture. We compared in vitro the effects of a combined treatment with GM-CSF (10 ng/mL) plus IL-3 (10 ng/mL) on the metabolism and cytotoxicity of Ara-C in normal bone marrow mononuclear cells (NBMMC) and AML blasts. NBMMC from six healthy volunteers and AML blasts from 10 patients were incubated for 20 hours with or without IL- 3 plus GM-CSF, followed by a concurrent treatment with Ara-C for 4 additional hours. Exposure to the HGFs and Ara-C produced significantly higher intracellular Ara-CTP levels as well as higher Ara-CTP/dCTP pool ratios in AML blasts as compared with NBMMC. Treatment with HGFs resulted in [3H] Ara-C DNA incorporation that was significantly higher in AML blasts versus NBMMC. This selective improvement of Ara-C metabolism in AML blasts was associated with an enhanced Ara-C-mediated leukemia colony-forming unit (CFU) growth inhibition. In contrast, exposure to HGFs resulted in an improved colony growth of normal CFU granulocyte-monocyte and CFU-granulocyte, erythroid, monocyte, megakaryocyte. These in vitro studies indicate that a combined treatment with IL-3 plus GM-CSF may improve the selectivity of Ara-C against AML blasts. 相似文献
85.
P C Avgerinos L K Nieman E H Oldfield T Loughlin K M Barnes D L Loriaux G B Cutler 《The Journal of clinical endocrinology and metabolism》1989,68(5):912-916
Successful transsphenoidal surgery for Cushing's disease leads to secondary adrenal insufficiency in most patients. This form of transient adrenal insufficiency is thought to result from hypothalamic and pituitary suppression due to the preceding hypercortisolism. Whether the rate-limiting step in the recovery of adrenal function in this setting is the hypothalamic CRH neuron or the pituitary corticotroph cell, however, is not known. We studied this question by examining the response to ovine CRH (oCRH) before, during, and after prolonged pulsatile administration of human CRH (hCRH) beginning 1-2 weeks after curative microadenomectomy for Cushing's disease. Five patients cured of Cushing's disease received eight hCRH injections (1 microgram/kg) daily for 7 days. This CRH regimen was found previously to normalize plasma ACTH and cortisol patterns in patients with secondary adrenal insufficiency who had normal ACTH responses to a single injection of oCRH (hypothalamic adrenal insufficiency). The plasma ACTH and cortisol responses to oCRH (1 microgram/kg at 2000 h) were assessed immediately before, 2.5 h after, and 7 days after the end of pulsatile hCRH administration. To control for time-related improvement in the hormonal response to ovine CRH, an additional five patients cured of Cushing's disease underwent oCRH tests 1-2 and 3-4 weeks after transsphenoidal surgery, but did not receive hCRH. There was no significant difference in basal or oCRH-stimulated plasma ACTH and cortisol levels among any of the three oCRH tests in the patients who received hCRH. The baseline and oCRH-stimulated plasma ACTH and cortisol levels 1-2 and 3-4 weeks after surgery in the patients who did not receive pulsatile hCRH were similar to the values at those times in the patients who received pulsatile hCRH. Compared to normal subjects, however, both the hCRH-treated and non-hCRH-treated patients had significantly decreased peak and time-integrated plasma ACTH and cortisol responses to oCRH. We conclude that an impaired pituitary response to CRH contributes to the postoperative hypocortisolism of patients recently cured of Cushing's disease, and that this impaired pituitary response to CRH is not reversible by 1 week of pulsatile hCRH administration. 相似文献
86.
87.
Ryder JJ Garrison K Song F Hooper L Skinner J Loke Y Loughlin J Higgins JP MacGregor AJ 《Annals of the rheumatic diseases》2008,67(5):584-591
We conducted a systematic review of genetic association studies for osteoarthritis of the peripheral joints (OA) and spinal degenerative disease (SDD). Electronic searches were carried out for any English language article reporting on a gene association study for either OA or SDD published up until the end of 2006. A team of seven reviewers used a standardised template to extract data in duplicate. In all, 90 studies fulfilled our inclusion criteria, reporting a total of 94 significant associations from 83 different genes. We found relatively few instances in which a specific gene-disease association had been analysed by more than one study, and there were 14 cases in which significant associations were replicated in independent studies (at joints associated with the AGC1, ASPN, COL9A2, COL9A3, COL11A2, ESR1, FZRB, HFE, IL1A, IL1RN, PTGS2 and VDR genes). METHOD: logical and reporting problems were widespread, including failure to report full results, missing population details, multiple testing, and over-reliance on subgroup analysis. In summary, the complex phenotypes of OA and SDD may have made it difficult for researchers to focus their efforts. The field is dominated by isolated analyses of disparate potential associations, a problem that is amplified by the frequent analysis of different polymorphisms within individual genes. Flaws in study methodology and interpretation undoubtedly increase the risk of publication bias. Closer adherence to published recommendations (in particular those produced by HuGENet) will help to ensure that future studies are well-designed and build on current understanding, rather than simply adding to the growing bank of potential associations. 相似文献
88.
89.
90.
Host adaptation and immune modulation are mediated by homologous recombination in Helicobacter pylori 总被引:2,自引:0,他引:2
Rearrangement of genomic DNA via homologous recombination provides an alternative mechanism of gene regulation that is essential for successful colonization of the gastric mucosa by Helicobacter pylori. Inoculation of outbred mice with the H. pylori SS1 wild-type strain elicited a T helper (Th) 2 response and established a persistent infection. In contrast, inoculation with an isogenic H. pylori strain defective for homologous recombination elicited a Th1-mediated immune response and clearance of infection within 70 days. We, therefore, demonstrate that recombination is critical for mediating persistence of a microbial pathogen through the induction of ineffective immune responses. 相似文献