首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   11009篇
  免费   664篇
  国内免费   83篇
耳鼻咽喉   85篇
儿科学   150篇
妇产科学   150篇
基础医学   1319篇
口腔科学   206篇
临床医学   1067篇
内科学   3053篇
皮肤病学   124篇
神经病学   891篇
特种医学   368篇
外科学   1818篇
综合类   57篇
一般理论   1篇
预防医学   751篇
眼科学   85篇
药学   769篇
中国医学   15篇
肿瘤学   847篇
  2024年   10篇
  2023年   83篇
  2022年   149篇
  2021年   369篇
  2020年   190篇
  2019年   361篇
  2018年   460篇
  2017年   289篇
  2016年   282篇
  2015年   359篇
  2014年   495篇
  2013年   600篇
  2012年   956篇
  2011年   975篇
  2010年   538篇
  2009年   434篇
  2008年   698篇
  2007年   744篇
  2006年   625篇
  2005年   677篇
  2004年   623篇
  2003年   552篇
  2002年   548篇
  2001年   98篇
  2000年   67篇
  1999年   85篇
  1998年   97篇
  1997年   54篇
  1996年   52篇
  1995年   45篇
  1994年   31篇
  1993年   35篇
  1992年   29篇
  1991年   26篇
  1990年   12篇
  1989年   16篇
  1988年   11篇
  1987年   6篇
  1986年   16篇
  1985年   8篇
  1984年   5篇
  1983年   8篇
  1982年   4篇
  1981年   5篇
  1979年   4篇
  1975年   4篇
  1974年   5篇
  1973年   3篇
  1971年   3篇
  1970年   3篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
81.
Thrombocytopenia is a major cause of morbidity following intensive chemotherapy for acute leukemia. Over recent years, there has been an increasing use of platelet transfusions which, although generally efficacious to prevent severe hemorrhage, have associated risks of transmitting blood-borne disease and of alloimmunization. Therefore, there is a clinical requirement for a drug that will reliably alleviate the thrombocytopenia associated with leukemia therapy. The c-mpl ligand thrombopoietin is the most interesting factor for the treatment of thrombocytopenia because of its lineage specificity. Phase I and II studies confirm its biological efficacy to induce rise in platelet count in patients with solid tumors and acute leukemia. Several other pleiotropic hematopoietic growth factors are also currently in clinical trials. These include interleukin-6, interleukin-3, interleukin-11, PIXY321 and stem cell factor. The effects of these cytokines appear to be modest at most and, with the exception of interleukin-11, their side effects are likely to limit their clinical application. Combinations of factors may prove more efficacious approaches to enhance platelet recovery.  相似文献   
82.
83.
由中华医学会内分泌学分会主办,国际内分泌学会参加的2006年内分泌代谢性疾病系列研讨会——全脚内分泌肿瘤基础和临床研究专题研讨会,于7月7~9日在西南省昆明市举办。此次大会是中华医学会内分泌学分会与国际内分泌学会首次联合举办的大会。国际内分泌学会山执行委员,负责学术会议的主席、肾上腺疾病研究方面的专家法国Xavier Bertagna教授带队,由国际内分泌学会邀请了分别在神经内分泌和甲状腺疾病领域深有研究的著名专家英旧Ashley Grossman教授和美国James A Fagha教授,……  相似文献   
84.
Aim: Fabry disease is considered primarily as a progressive small vessel disease, with ischaemic degenerative lesions involving the kidneys, brain and heart. Macrovascular involvement in male patients includes an accelerated wall hypertrophy of the radial artery and a thickening of the intima–media of the common carotid artery. The aim of this study is to evaluate the prevalence and severity of carotid artery atherosclerosis in hemizygous and heterozygous patients with Fabry disease, compared with a matched control population.
Methods: The common carotid artery intima–media thickness (IMT) of 53 patients with Fabry disease (24 men, 29 women) was measured by high-definition ultrasonography, and the presence or absence of atherosclerotic plaques reported. Results were compared with those of 120 age-matched healthy individuals (83 men, 37 women).
Results: The common carotid artery IMT was increased to the same extent in male and female patients with Fabry disease (706±211 µm and 749±395 µm, respectively) compared with that of the control population (614±113 µm). In the Fabry population, IMT did not correlate with either systolic blood pressure or with renal function (plasma creatinine). In the control population, only systolic blood pressure was positively and significantly correlated with IMT. Atherosclerotic plaques in the common carotid artery were not observed in any patient with Fabry disease, whereas 34% of the control population had carotid artery plaques, as evidenced by focal non-homogeneous intima–media thickening greater than 1.2 mm.
Conclusion: This study presents evidence of a major increase in common carotid artery IMT, both in hemizygous and heterozygous patients with Fabry disease, in the absence of focal atherosclerotic plaques. These results suggest that the conduit arteries may be protected from atherosclerosis in Fabry disease.  相似文献   
85.
It has been reported that benzylamine reduces blood glucose in rabbits, stimulates hexose uptake, and inhibits lipolysis in mouse, rabbit, and human adipocytes. In the presence of vanadate, benzylamine is also able to improve glucose disposal in normoglycaemic and diabetic rats. Such insulin-mimicking properties are the consequence of hydrogen peroxide production during benzylamine oxidation by semicarbazide-sensitive amine oxidase (SSAO). The aim of the study was to determine whether other SSAO-substrates could share such potential antidiabetic properties. Thus, mafenide, a synthetic antimicrobial sulfonamide structurally related to benzylamine, and which has been recently reported to interact with SSAO, was tested in the above mentioned models, in parallel with methylamine, a proposed endogenous SSAO-substrate. All tested amines stimulated glucose uptake and inhibited lipolysis in rat and mouse fat cells. Methylamine and benzylamine, but not mafenide, reduced the hyperglycaemic response during a glucose tolerance test in rabbits while the three amines tested were devoid of insulin-releasing activity under both in vivo and in vitro conditions. In human adipocytes, mafenide did not stimulate glucose transport since it was not a high-affinity substrate for SSAO and generated less hydrogen peroxide than benzylamine or methylamine. Therefore, mafenide could not be considered as an antidiabetic drug despite being oxidized and exhibiting insulin-mimicking effects in rat and mouse adipocytes. By contrast, the endogenous substrate methylamine improved glucose utilization in all in vitro and in vivo models, leading to consider novel SSAO substrates as drugs with potential anti-hyperglycaemic properties.  相似文献   
86.
87.
Serum beta2-microglobulin, the light chain of the HLA class I molecular complex, remains one of the best survival prognostic factors in multiple myeloma, but other HLA class I molecules might be of interest in monoclonal gammopathies. In this study, we evaluate total soluble HLA class I (HLA-Is) and soluble HLA-G (HLA-Gs) in 103 patients with newly diagnosed multiple myeloma, 30 patients with monoclonal gammopathy of undetermined significance (MGUS), and 30 healthy subjects, studying their prognostic value in multiple myeloma. In multiple myeloma patients, HLA-Is and HLA-Gs median values were 0.8 microg/mL and 28 ng/mL, respectively. Median HLA-Is concentration was higher in stage II and III multiple myeloma patients than in stage I multiple myeloma, MGUS, and control patients. Median HLA-Gs was significantly lower in healthy controls than in MGUS and multiple myeloma patients. A high level of HLA-Is (> or =2.1 microg/mL) was predictive of short survival (P = 0.017). For each given level of beta2-microglobulin, the relative risk of death was higher for patients with HLA-Is > or = 2.1 microg/mL than in patients with a lower level (P = 0.047). HLA-Gs, a marker of monoclonal gammopathy, was of no prognostic value, but the addition of HLA-Is to beta2-microglobulin produced an efficient prognostic score (P < 0.0001). HLA-Is is a new marker of multiple myeloma tumor load and provides additional survival prognostic information to beta2-microglobulin.  相似文献   
88.
We describe herein the structural optimization of new piperamide analogues, designed from two natural prototypes, piperine 1 and piperdardine 2, obtained from Piper tuberculatum Jacq. (Piperaceae). Molecular modeling studies using semiempirical AM1 method were made in order to establish rational modifications to optimize them by molecular simplification. The targeted compounds (10) and (11) were respectively obtained using benzaldehyde (12) and para-anisaldehyde (13) as starting materials. 1H NMR spectra showed that the target compounds were diastereoselectively obtained as the (E)-isomer, the same geometry of the natural prototypes. These new synthetic amides presented significant hypotensive effects in cardiovascular essays using in vivo methodologies. Compound 11 (N-[5-(4′-methoxyphenyl)-2(E)-pentenoyl]thiomorpholine) showed a potency 10,000 times greater than its prototype 5, evidencing an optimization of the molecular architecture for this class of hypotensive drug candidates.  相似文献   
89.
In the approach to lipid-related risk factors for cardiovascular diseases, serum high density lipoprotein-cholesterol (HDL-C) levels bear a particular significance as this lipoprotein is considered to be an antiatherogenic factor mainly, but not only, because of its influence and impact on reverse cholesterol transport. Hence the need and requirement to consider serum HDL-C levels for both primary and secondary prevention of cardiovascular disease. A particularly important aspect is the association of the 'low HDL syndrome' with the metabolic syndrome. These factors force us to consider serum HDL-C level as a therapeutic target by itself, or even in association with low density lipoprotein-cholesterol (LDL-C) levels when the latter are increased. This review stresses the aspects connecting serum HDL-C levels and cardiovascular risk, and looks at the populations that should be considered amenable to therapeutic management because of low serum HDL-C levels. We review therapeutic strategies, both pharmacological and nonpharmacological. The aim of this review is to present therapeutic management recommendations for correcting the proportion of cardiovascular risk that is attributable to changes in HDL-C. Serum HDL-C levels of >40 mg/dL must be a therapeutic target in primary and secondary prevention. This goal is particularly important in patients with low serum HDL-C levels and ischemic heart disease (IHD) or its equivalents, even if the therapeutic target for serum LDL-C levels (<100 mg/dL) has been achieved. The first choice for this clinical condition is fibric acid derivates. The same therapeutic option should be considered in patients without IHD with low serum HDL-C levels and high cardiovascular risk (>20%), hypertriglyceridemia, type 2 diabetes mellitus, or metabolic syndrome.  相似文献   
90.
In developed countries, endometrial carcinoma is the most common cancer that affects the female genital tract. Endometrial carcinoma is divided into two main histological types, type I or endometrioid and type II or non‐endometrioid, each of which have characteristic, although not exclusive, molecular alterations and mutational profiles. Nevertheless, information about the implication and relevance of some of these genes in this disease is lacking. We sought here to identify new recurrently mutated genes in endometrioid cancers that play a role in tumourigenesis and that influence the clinical outcome. We focused on low‐grade, non‐ultramutated tumours as these tumours have a worse prognosis than the ultramutated POLE‐positive endometrioid endometrial carcinomas (EECs). We performed exome‐sequencing of 11 EECs with matched normal tissue and subsequently validated 15 candidate genes in 76 samples. For the first time, we show that mutations in chromatin remodelling‐related genes (KMT2D, KMT2C, SETD1B and BCOR) and in DNA‐repair‐related genes (BRCA1, BRCA2, RAD50 and CHD4) are frequent in this subtype of endometrial cancer. The alterations to these genes occurred with frequencies ranging from 35.5% for KMT2D to 10.5% for BRCA1 and BCOR, with some showing a tendency toward co‐occurrence (RAD50KMT2D and RAD50‐SETD1B). All these genes harboured specific mutational hotspots. In addition, the mutational status of KMT2C, KMT2D and SETD1B helps to predict the degree of myometrial invasion, a critical prognostic feature. These results highlight the possible implication of these genes in this disease, creating opportunities for new therapeutic approaches.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号