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   33289篇
  免费   1939篇
  国内免费   269篇
耳鼻咽喉   445篇
儿科学   598篇
妇产科学   491篇
基础医学   4074篇
口腔科学   1553篇
临床医学   2724篇
内科学   8946篇
皮肤病学   392篇
神经病学   3350篇
特种医学   1309篇
外科学   5293篇
综合类   93篇
一般理论   6篇
预防医学   1395篇
眼科学   546篇
药学   1727篇
中国医学   72篇
肿瘤学   2483篇
  2024年   32篇
  2023年   360篇
  2022年   669篇
  2021年   1256篇
  2020年   745篇
  2019年   1022篇
  2018年   1205篇
  2017年   956篇
  2016年   1067篇
  2015年   1130篇
  2014年   1459篇
  2013年   1777篇
  2012年   2776篇
  2011年   2672篇
  2010年   1499篇
  2009年   1363篇
  2008年   2145篇
  2007年   2256篇
  2006年   2031篇
  2005年   1843篇
  2004年   1643篇
  2003年   1495篇
  2002年   1298篇
  2001年   263篇
  2000年   237篇
  1999年   241篇
  1998年   240篇
  1997年   201篇
  1996年   153篇
  1995年   141篇
  1994年   127篇
  1993年   106篇
  1992年   118篇
  1991年   93篇
  1990年   81篇
  1989年   54篇
  1988年   86篇
  1987年   61篇
  1986年   45篇
  1985年   63篇
  1984年   52篇
  1983年   44篇
  1982年   46篇
  1981年   29篇
  1980年   24篇
  1979年   41篇
  1978年   31篇
  1977年   22篇
  1973年   31篇
  1972年   27篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
We describe a case of bronchiolitis obliterans-organizing pneumonia (BOOP) with asbestos bodies. A 65-year-old man, treated in the past for gastric lymphoma and with an history of asbestos exposure, presented with fever and two nodular opacities in the lower lobe of the left lung. Histologic examination revealed a BOOP pattern; in the inflammatory tissue some asbestos bodies were present. Patients exposed to asbestos may rarely present with localized inflammatory pulmonary lesions. In these cases, the possible etiopathogenetic role of asbestos needs further studies.  相似文献   
103.
BACKGROUND: Lethal varicella in immunocompetent hosts is rare and its pathogenesis is largely unknown. The discovery of glycoprotein E (gE) mutants showing attributes consistent with increased virulence in vitro and in animal models, provided a possible molecular mechanism underlying a more aggressive virus infection. However, these mutants have never been associated with unusually severe clinical cases. OBJECTIVES: To varicella-zoster virus (VZV) mutations that correlate with increased virulence. RESULTS: We report a case of fatal hepatitis caused by a VZV bearing a novel mutation on the 3B3 monoclonal antibody epitope of gE in an immunocompetent host. CONCLUSIONS: This report describes a mutant VZV responsible for an aggressive clinical course in an immunocompetent host. Linking these severe clinical presentations of VZV infection to virus mutations might provide insights into the underlying pathogenic mechanisms.  相似文献   
104.
Neuropsychological deficits were investigated with respect to regional distribution of cerebral atrophy as assessed by volumetric magnetic resonance imaging (MRI) in 50 patients with Alzheimer's dementia (AD; NINCDS-ADRDA criteria) and 20 healthy volunteers. When compared between groups, test performance of all investigated neuropsychological domains including declarative memory, language, praxia, psychomotor speed, as well as attention and concentration was significantly impaired. These deficits were differentially correlated with regional atrophic changes. In particular, volumes of the right amygdala-hippocampus complex correlated with declarative memory performance, whereas volumes of the left temporo-parietal regions correlated with performance in naming and praxia. Furthermore, left frontal lobe atrophy was associated with verbal fluency. Our data confirm the central role that medial temporal atrophy plays for declarative memory deficits in AD and indicate that additional changes in the parietal, temporal and frontal lobes are responsible for further neuropsychological deficits characteristic of this disorder.  相似文献   
105.
Although B-cell chronic lymphocytic leukemia (B-CLL) is the most common form of leukemia in Western countries, little is known about its underlying molecular abnormalities and their prognostic significance, particularly for use in early therapeutic interventions in young patients. As TP53 tumor suppressor gene abnormalities and 11q23 deletions are reported to be prognostically adverse in hematologic malignancies, we used interphase fluorescence in situ hybridization to analyze their incidence and prognostic significance in young B-CLL patients. Bone marrow samples from 40 untreated B-CLL patients at diagnosis were studied using five yeast artificial chromosome clones from the 11q23.1 approximately q23.3 chromosomal region and a probe specific for the 17p13.1 locus. Twenty-three patients (58%) carried 11q deletions. Interestingly, 16 of 17 patients (94%) who showed early disease progression exhibited this chromosomal abnormality, suggesting that 11q deletions may help to identify more aggressive disease in early stage patients. In contrast, monoallelic TP53 deletions were found in all of the patients. The TP53 and 11q deletions were only present in a proportion of the clonal B-cells, which suggests that they are secondary events in B-CLL.  相似文献   
106.
Two prototypes of sensing devices for detecting peridomestic populations of Triatoma infestans Klug were tested in paired trials with bamboo canes in Amamá and nearby rural villages under triatomine surveillance. In infested peridomestic structures housing domestic animals, 1-2 pairs of numbered devices were placed per test site, left for 3-9 nights, and inspected for evidence of infestation. Prototype A was a black plastic cylinder 19 cm high and 10 cm diameter, with a screw cap on the top, 2 openings in the bottom, and a removable central structure made of resistant plastic coated with leather. Prototype B had square leather pieces rolled into cylinders instead of the central structure. Prototype A was significantly more sensitive than the bamboo cane with pleated paper inside in 13 test sites in which 20 pairs were tried. In a smaller series involving 7 pairs, prototype B also detected infestations more frequently than the cane. Triatomine feces were the signs most frequently recorded by both prototypes, whereas the bamboo canes recorded no feces. Ten T. infestans and 1 Triatoma guasayana Wygodzinsky & Avalos were collected from the prototypes placed on the ground or walls, not beneath the thatched roofs of the animal shelters, whereas only 3 T. infestans were collected from the canes. This study describes an effective sensing device for detecting T. infestans populations in outdoor animal shelters and provides quantitative field data on its performance.  相似文献   
107.
108.
The sensitivity of preoperative imaging was evaluated for the localization of insulinomas in 2 series of 54 and 17 patients, respectively. In the first series, diagnosis was obtained with ultrasonography (US) in 14.8%, with computed tomographic (CT) scan in 60%, and with arteriography and/or angio CT scan in 75% of patients. In the second series, US, CT scan, and arteriography were performed preoperatively showing a sensitivity of 53% of one or more of the imaging techniques. The last 17 patients all underwent intraoperative pancreatosonography, and the insulinoma was localized in each. Considering the high reliability of intraoperative ultrasonography, and the high costs and low benefits of other current diagnostic techniques, a new management plan is suggested for patients with a definite laboratory diagnosis of insulinoma.
Resumen La sensibilidad de la imagenología preoperatoria para la localización de insulinomas fue evaluada en 2 series de 54 y 17 pacientes respectivamente. En la primera serie, el diagnóstico fue logrado con ultrasonografía en 14.8%, con escanografía computadorizada en 60%, y con arteriografía y/o angiografía con escanografía computadorizada en 75% de los casos. En la segunda serie, la ultrasonografía, la escanografía computadorizada, y la arteriografía fueron realizadas preoperatoriamente demostrando una sensibilidad de 53% en una o más de las técnicas de imagenología. En los últimos 17 pacientes se realizó pancreatosonografía, la cual permitió la localización del tumor en 100% de los casos.En consideración a la elevada confiabilidad de la ultrasonografía intraoperatoria, y los altos costos y bajo rendimiento de las técnicas corrientes de diagnóstico, se sugiere un nuevo plan de manejo para pacientes con un diagnóstico de laboratorio certero de insulinoma. Se fundamenta en la localización ultrasonográfica intraoperatoria del tumor, la cual puede ser aplicada en los más comprensivos centras médicos.

Résumé La sensibilité de l'imagerie pré-opératoire permettant la localisation des insulinomes a été étudiée dans 2 séries de 54 et 17 sujects. Dans la première série le diagnostic fut posé par l'échographie dans 14.8% des cas, par la tomodensitométrie dans 60% des cas, par l'artériographie et/ou l'angiotomodensitométrie dans 75% des cas. Dans la seconde série, l'échographie, la tomodensitométrie et l'artériographie furent pratiquées avant l'intervention avec une sensibilité de 53% pour l'une ou pour plusieurs techniques. Chez les 17 derniers malades l'échographie opératoire fut systématiquement pratiquée et permit la localisation de la tumeur dans 100% des cas.Considérant la haute fiabilité de l'échographie opératoire, le coût élevé et les faibles résultats des autres techniques de diagnostic, un nouveau plan d'investigation est proposé pour explorer les malades qui présentèrent certains signes biologiques d'insulinome. Il repose sur la localisation per-opératoire de la tumeur par l'échographie, méthode qui peut être pratiquée dans des centres spécialisés.
  相似文献   
109.
The cirrhotic condition is characterized by a series of changes in physiological functions and of subclinical alterations that imply an abnormal and fragile adaptive pattern with reduced resistance to superimposed distress. In the care of the critically ill cirrhotic patient, the supportive measures aimed at maintaining physiological stability through the control of such debilitating factors have a key role and are not secondary in importance to the more obvious measures needed to treat clinically evident and specific alterations or complications. The relationship between hepatic malfunction and the development of these physiological abnormalities is not fully understood. Our knowledge of the problem, however, has been recently improved and the need for supportive measures motivated by a series of notions on cardiorespiratory and metabolic abnormalities and interactions in hepatic decompensation.
Resumen La condición cirrótica se caracteriza por una serie de cambios en las funciones fisiológicas y por alteraciones subclinicas que implican un patrón de adaptación anormal y fragil de resistencia reducida al estrés. Estas incluyen disfunción respiratoria con tendencia a la hipoxemia arterial en presencia de elevados indices cardiacos, una situatión crónica de hiperdinamismo cardiovascular pero con precaria eficacia miocárdica y latente riesgo de falla de alto débito, y cambios metabólicos que se traducen en un estado de fallas multisistémicas interrelacionadas características del cirrótico. En el cuidado del paciente cirrótico en estado crítico, las medidas de soporte orientadas al mantenimiento de la estabilidad fisiológica mediante el control de tales factores debilitantes tienen una importancia capital y no son secundarias frente a aquellas muy obvias que se requieren para tratar alteraciones o complicaciones específicas y clínicamente evidentes. La relación entre la disfunción hepática y el desarrollo de las mencionadas anormalidades fisiológicas no está totalmente aclarada, sin embargo, el estado de nuestro conocimiento sobre el problema ha sido enriquecido recientemente y se ha fortalecido la necesidad de establecer medidas de soporte por una serie de nociones relativas a las anormalidades e interacciones cardiorrespiratorias y metabólicas de la descompensación hepática.

Résumé La cirrhose est caractérisée par des séries de variations des fonctions physiologiques et de modifications cliniques qui impliquent des modalités d'adaptation anormale et fragile se traduisant par une résistance réduite à l'état de détresse ou peut se trouver le cirrhotique. Des mesures appropriées pour maintenir la stabilité physiologique ont un rôle principal en présence de ces facteurs défavorables. Elles ne doivent pas être considérées comme moins importantes que les mesures essentielles qui sont nécessaires pour traiter les complications et les modifications cliniques spécifiques. La relation entre l'altération des fonctions du foie et le développement des anomalies physiologiques précitées n'est pas parfaitement élucidée, cependant, nos connaissances de ce problème ont été récemment améliorées et le besoin de mesures adéquates de soutien est devenu manifeste en raison de séries acquises de notions concernant les anomalies cardio-respiratoires et métaboliques ainsi que les interactions de la décompensation hépatique.
  相似文献   
110.
Advances in Health Sciences Education - Professional identity is believed to foster self-confidence and resilience in health care professionals. While literature exists describing professional...  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