全文获取类型
收费全文 | 62330篇 |
免费 | 3111篇 |
国内免费 | 441篇 |
专业分类
耳鼻咽喉 | 625篇 |
儿科学 | 1239篇 |
妇产科学 | 1830篇 |
基础医学 | 7472篇 |
口腔科学 | 2413篇 |
临床医学 | 4886篇 |
内科学 | 17328篇 |
皮肤病学 | 1317篇 |
神经病学 | 5426篇 |
特种医学 | 1629篇 |
外科学 | 9232篇 |
综合类 | 278篇 |
一般理论 | 12篇 |
预防医学 | 3772篇 |
眼科学 | 986篇 |
药学 | 3400篇 |
中国医学 | 207篇 |
肿瘤学 | 3830篇 |
出版年
2024年 | 52篇 |
2023年 | 477篇 |
2022年 | 1157篇 |
2021年 | 2131篇 |
2020年 | 1145篇 |
2019年 | 1681篇 |
2018年 | 2279篇 |
2017年 | 1479篇 |
2016年 | 1590篇 |
2015年 | 1824篇 |
2014年 | 2552篇 |
2013年 | 3265篇 |
2012年 | 4987篇 |
2011年 | 4963篇 |
2010年 | 2739篇 |
2009年 | 2408篇 |
2008年 | 4129篇 |
2007年 | 4187篇 |
2006年 | 3947篇 |
2005年 | 3865篇 |
2004年 | 3457篇 |
2003年 | 3062篇 |
2002年 | 2777篇 |
2001年 | 452篇 |
2000年 | 386篇 |
1999年 | 474篇 |
1998年 | 479篇 |
1997年 | 400篇 |
1996年 | 372篇 |
1995年 | 356篇 |
1994年 | 278篇 |
1993年 | 216篇 |
1992年 | 233篇 |
1991年 | 174篇 |
1990年 | 173篇 |
1989年 | 144篇 |
1988年 | 116篇 |
1987年 | 107篇 |
1986年 | 130篇 |
1985年 | 111篇 |
1984年 | 107篇 |
1983年 | 95篇 |
1982年 | 122篇 |
1981年 | 96篇 |
1980年 | 98篇 |
1979年 | 62篇 |
1978年 | 63篇 |
1977年 | 53篇 |
1974年 | 55篇 |
1973年 | 52篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
Pyroglutamyl, proline-rich oligopeptides, classically referred to as bradykinin-potentiating peptides (BPPs) are found in Bothrops jararaca venom, and are naturally occurring inhibitors of the somatic angiotensin-converting enzyme (ACE). The chemical and pharmacological properties of these peptides were essential for the development of captopril, the first active site directed inhibitor of ACE, currently used to treat human hypertension. ACE is a complex ectoenzyme of the vascular endothelium, possessing two catalytic sites, performing diverse specific roles. Recent advances concerning novel features of BPPs revealed that they might still contribute to a better understanding of the cardiovascular physiology and pathology. The molecular biology of the BPPs revealed that they are part of two distinct C-type natriuretic peptide precursors found in the venom gland and the brain of B. jararaca, each containing seven BPPs. In situ hybridization studies detected the presence of the corresponding mRNA precursor in snake brain regions correlated with neuroendocrine functions, such as the ventro-medial hypothalamus, the paraventricular nuclei, the paraventricular organ, and the subcommissural organ. In this article we discuss the large variety of homologous BPPs in B. jararaca venom and brain, its significance, and whether the BPPs could represent novel endogenous neuropeptides. 相似文献
42.
Thomas G. Hardy Jr. M.D. Pedro S. Aguilar M.D. Dr. William R. C. Stewart M.D. 《Diseases of the colon and rectum》1989,32(6):528-532
Three patients with complete colonic obstruction treated by primary resection and anastomosis with intraoperative colon tube decompression and bowel lumen sterilization without a protective colostomy are presented. An improved colonic decompressor was used. It is postulated that this procedure is an alternative safe technique in patients with colonic obstruction in whom an end-colostomy, mucous fistula, or Hartmann pouch would be necessary. 相似文献
43.
44.
Francisco Jose Martinez-Guijarro Eduardo Soriano Jose Antonio del Rio Carlos Lopez-Garcia 《Brain research》1991,547(2)
An antibody against the calcium binding protein parvalbumin selectively labels a set of neurons in the cerebral cortex of lizards. Golgi-like immunostained bipolar, multipolar and pyramid-like neurons appear mainly located in the inner plexiform layers. Parvalbumin-immunoreactive (PARV-IR) puncta are concentrated in the cell layer of the dorsal and dorsomedial cortices showing a basket-like distribution. The morphology and distribution of PARV-IR neurons and puncta overlap GABA-immunostaining in the cerebral cortex of lizards. Thus, it is likely that PARV-IR neurons are a subset of the cortical GABAergic neurons of lizards. 相似文献
45.
Antonio Gómez Mercedes Salgado Manuel Valladares-Ayerbes Mónica Jorge Ana Carballo Sonia Candamio Pilar Izquierdo Paula Peleteiro Rafael López 《Clinical & translational oncology》2010,12(12):843-848
Objective
The aim of the project was to assess the effectiveness and safety of weekly epoetin-beta (EB) in patients with gastrointestinal cancer (GIC) subjected to concomitant chemoradiotherapy (CCTRT). 相似文献46.
Carlos Ferrer Albiach Antonio Conde Moreno Marta Rodríguez Cordón Virginia Morillo Macías Ana Bouché Babiloni Inmaculada Beato Tortajada Ángel Sánchez Iglesias Alicia Francés Muñoz 《Clinical & translational oncology》2010,12(1):22-26
Hypoxia is related to poor prognosis because it is associated to chemo-and radioresistance. During recent years the evolution
of imaging methods like PET/CT and MRI has meant the appearance of new perspectives with direct implications in radiation
therapy. We discuss previous experiences in staging, planning and in the follow-up process with these techniques for measuring
tumour hypoxia. 相似文献
47.
48.
Estrella Fernández Fabrellas Luis Almenar Bonet Silvia Ponce Pérez José Antonio Moro López Rafael Blanquer Olivas Antonio Salvador Sanz 《Archivos de bronconeumologia》2009,45(4):173-180
Introduction and objectiveWhen sleep apnea-hypopnea syndrome (SAHS) and cardiovascular disease occur concurrently, prognosis is affected. Echocardiography can detect structural cardiac abnormalities but using this technique in all patients would place a heavy burden on resources. The objective of this study was to investigate whether the N-terminal fraction of brain natriuretic peptide (NT-proBNP) can be used as a marker for silent heart disease.Patients and methodsNT-proBNP concentration was measured in the 114 consecutive patients with SAHS who underwent echocardiography before starting treatment. Left and right ventricular systolic and diastolic function, as well as structural abnormalities, were studied. Correlations between NT-proBNP concentration and the abnormalities detected were investigated. A receiver operating characteristics (ROC) curve was plotted for NT-proBNP concentration and cardiac abnormalities.ResultsData for 98 patients were finally analyzed. NT-proBNP concentration was significantly correlated with ventricular septal thickness (r=0.63), posterior wall thickness (r=0.45), and left ventricular enddiastolic diameter (r=0.51) (P<.0001 for all correlations). The area under the ROC curve was significant (0.870; 95% confidence interval, 0.801-0.939; P<.0001). Assuming that specificity would be more useful for clinical practice, we calculated that NT-proBNP concentrations below 100 and 200 pg/mL could rule out structural abnormalities with a reliability of 90% and 100%, respectively.ConclusionsNT-proBNP concentration was strongly correlated with echocardiographic abnormalities and so could be a useful tool for identifying patients who should be referred to the cardiologist. 相似文献
49.
50.
Marco Antonio Palma Rocio Ortiz Carlos Alvarez-Dardet Maria T. Ruiz 《Social science & medicine (1982)》2009
The possible effect of Government Consumption (a component of Gross Domestic Product (GDP)) on attainment of the hunger Millennium Development Goal (MDG1) was analyzed by evaluating the effect of macroeconomic, social, demographic and policy variables on average undernourished population. Eighty-four developing countries with data available on undernourished population were included in an ecological study. Regression models were applied to explore possible determinants of Undernourished between 1990 and 2004 and consequent achievement of the projected 2004 MDG1. In 2004, 1.4% of the overall undernourished population in the studied countries [70.16 million people] was in excess of the projected level required to meet MDG1. The multiple linear regression showed significant associations between Undernourished and poverty levels, the Gini Index, rural population and Government Consumption. The multiple logistic regression showed significant associations between achievement of projected 2004 MDG1 levels and Government Consumption and the Gini Index. The significant associations between Undernourished and Government Consumption suggest that the effects of GDP components on social conditions call for more thorough research and that policymakers such as governments and international financial institutions need to ensure that changes in distributive and redistributive policies do not negatively affect the possibility of achieving MDG1. 相似文献