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   819篇
  免费   46篇
  国内免费   3篇
耳鼻咽喉   2篇
儿科学   5篇
基础医学   115篇
口腔科学   10篇
临床医学   45篇
内科学   239篇
皮肤病学   13篇
神经病学   97篇
特种医学   25篇
外科学   137篇
综合类   2篇
预防医学   12篇
眼科学   8篇
药学   44篇
中国医学   1篇
肿瘤学   113篇
  2023年   3篇
  2022年   8篇
  2021年   14篇
  2020年   3篇
  2019年   7篇
  2018年   16篇
  2017年   13篇
  2016年   20篇
  2015年   17篇
  2014年   17篇
  2013年   32篇
  2012年   51篇
  2011年   49篇
  2010年   36篇
  2009年   21篇
  2008年   47篇
  2007年   49篇
  2006年   39篇
  2005年   50篇
  2004年   46篇
  2003年   44篇
  2002年   41篇
  2001年   13篇
  2000年   16篇
  1999年   23篇
  1998年   15篇
  1997年   11篇
  1996年   8篇
  1995年   5篇
  1994年   12篇
  1993年   7篇
  1992年   8篇
  1991年   18篇
  1990年   9篇
  1989年   11篇
  1988年   15篇
  1987年   8篇
  1986年   5篇
  1985年   14篇
  1984年   8篇
  1983年   7篇
  1982年   3篇
  1981年   5篇
  1980年   3篇
  1979年   6篇
  1977年   3篇
  1974年   2篇
  1970年   3篇
  1965年   1篇
  1961年   1篇
排序方式: 共有868条查询结果,搜索用时 15 毫秒
71.
We reported a 29-year-old man with active endocarditis complicating aortic and mitral valve regurgitation. The echocardiogram showed a mycotic aneurysm at aortic valvular annulus and a aneurysm of mitral valve. Heart failure was progressive and caused anuria. Prior to emergent double valve replacement, 2,500 ml of water was removed. Then hemodynamics became stationary. Urination was good during and after operation. In this case, complicating acute renal failure, dehydration with extracorporeal ultrafiltration method was very effective for improvement of hemodynamics.  相似文献   
72.
73.
Pathology of carcinoma of the gallbladder   总被引:4,自引:1,他引:3  
A clinicopathologic study of 40 cases of carcinoma of the gallbladder is presented. Twenty-six cases resected were assessed retrospectively with respect to the operative procedures employed and the results based on the pathologic findings from the resected specimens.The relationship between clinical features, macroscopic forms of tumor, histological types, liver invasion, and lymph node metastasis were investigated. Papillary, papillary infiltrative and nodular forms were classified as either papillary adenocarcinoma or well-differentiated tubular adenocarcinoma and invasion of the liver and lymph node metastasis were rare. Frequent lymph node metastasis was encountered in the nodular infiltrative form and invasion of the liver was frequently present in the infiltrative form. Invasion of the liver, lymph node metastasis, and the presence of gallstones were less frequent in papillary adenocarcinoma. In contrast, moderately-differentiated tubular adenocarcinoma frequently had lymph node metastasis. Invasion of the liver and lymph node metastasis were, however, present regardless of the histologic types and were more related to the extent of subserosal involvement present. A female preponderance was noted in poorly-differentiated adenocarcinoma. The main reasons for surgery being limited to exploratory laparotomy only or palliative procedures included carcinoma infiltration into the hepatoduodenal ligament, carcinoma extension to the neighboring structures, multiple liver metastases, peritoneal dissemination, large liver invasion, and multiple metastases to the paraaortic lymph nodes.
Resumen Se presenta el estudio clínico patológico de 40 casos de carcinoma de la vesícula biliar. Veintiseis casos sometidos a resección fueron valorados en forma retrospectiva en cuanto a los procedimientos operatorios empleados y su resultado, con base en los hallazgos patológicos en los especímenes quirúrgicos.Se investigó la relación entre las características clínicas, las formas macroscópicas del tumor, la invasión hepática, y las metástasis a ganglios linfáticos. Las formas papilar, papilar infiltrante y nodular resultaron ser adenocarcinoma papilar o adenocarcinoma tubular bien diferenciado con ausencia casi total de invasión hepática y de metástasis ganglionares. Las metástasis ganglionares fueron encontradas frecuentemente en la forma nodular infiltrante y la invasión hepática apareció frecuente en la forma infiltrante. La invasión hepática, las metástasis ganglionares, y la presencia de cálculos en la vesícula biliar fueron menos frecuentes en el adenocarcinoma papilar. Por el contrario, el adenocarcinoma tubular moderadamente diferenciado exhibió frecuentes metástasis ganglionares. Sin embargo, la invasión hepática y las metastasis ganglionares estuvieron presentes sin distinción del tipo histológico y más bien se encontraron relacionadas con el grado de infiltración subserosa. Se observó un predominio del sexo femenino en el adenocarcinoma pobremente diferenciado. Las razones principales para limitar el tratamiento quirúrgico a laparotomía exploratoria o procedimientos paliativos fueron la infiltración del ligamento hepatoduodenal, la extensión carcinomatosa a las estructuras vecinas, las metástasis hepáticas múltiples, la diseminación peritoneal, la invasión mayor del hígado, y las metástasis múltiples a los ganglios para-aórticos.

Résumé L'étude clinicopathologique de 40 cas de cancer de la vésicule biliaire est présentée ici. Trente-six cas de résection ont été étudiés en ce qui concerne les types d'intervention et leur résultat appuyé rétrospectivement sur les données anatomopathologiques des pièces.Les rapports entre les caractères cliniques, les formes macroscopiques de tumeurs, les types histologiques, l'envahissement du foie, et les métastases ganglionnaires ont été examinés. Les formes papillaires, papillaires infiltrantes et ganglionnaires étaient soit cancer papillaire soit cancer tubulaire bien différencié et l'envahissement du foie et les métastases ganglionnaires étaient presque totalement absents. Il y avait de nombreuses métastases ganglionnaires dans la forme nodulaire infiltrante et l'envahissement du foie était fréquent dans la forme infiltrante. L'envahissement du foie, les métastases ganglionnaires et les calculs étaient moins fréquents que dans le cancer papillaire. Par contre, le cancer tubulaire peu différencié était souvent associé avec des métastases ganglionnaires. Cependant, l'envahissement du foie et les métastases ganglionnaires étaient sans rapport avec les types histologiques et plus en relation avec l'étendue de l'envahissement sous séreux. On a remarqué une majorité de femmes pour le cancer peu différencié. Les raisons majeures de se limiter à la laparotomie exploratrice ou à un procédé palliatif comprennent l'envahissement cancéreux du ligament hépatoduodénal (petit épiploon), l'extension du cancer aux structures adjacentes, des métastases multiples au foie, la dissémination péritonéale, un grand envahissement du foie, et de nombreuses métastases aux ganglions paraaortiques.
  相似文献   
74.
This study was undertaken to see how many people could receive the ventricular assist device (VAD) as a bridge to heart transplantation and to get selection criteria of the recipient. From January 1984 to December 1987, 9916 patients were admitted to our institute and 399 cases of them were dead. All dead cases were examined in terms of age, heart disease, other organ function, infection, and so on. There were 42 possible candidates for VAD, 31 men and 11 women. The average age was 50 years with a range from 22 to 63 years. Ten cases (23.8%) of them had the indication for VAD bridge to transplantation. The criteria for transplantable patients included the following three categories: I) Cardiogenic shock: Irreversible left or double ventricular failure with or without life-threatening dysrhythmia during IABP therapy--4 cases. II) End-stage valvular heart disease; Operation under VAD stand-by--2 cases. III) Postoperative refractory ventricular pump failure: Failure to wean from assist circulation after IABP trial or sustained ventricular failure under IABP support--4 cases. It was indicated that continuous precise evaluation of the deteriorating hemodynamics and the intensive care for major organ functions (renal, pulmonary, neurologic, hepatic, coagulation, etc.) were important to select the candidate for VAD bridge to heart transplantation.  相似文献   
75.
76.
A-49-year-old man was admitted because of a lower abdominal mass. During the five days prior to admission, he had noted fever and lower abdominal pain. Palpation of the abdomen revealed a tender mass, 10 cm in diameter, in the suprapubic region. An x-ray revealed an irregular collection of gas, 9 cm in diameter, in the pelvic cavity, which appeared as a mirror image when the patient was upright. Based on the physical finding and the results of a barium enema, abdominal CT, MRI, and small intestine imaging, a diagnosis of leiomyosarcoma of the ileum was made. Excision of the tumor and part of the small intestine was performed. A saccular tumor, 11 x 6 x 5 cm, was found 1.0 m from the cecum and growing out of the wall of the ileum. A large amount of pus was found inside the cavity. The pathological diagnosis was leiomyosarcoma.  相似文献   
77.
We hypothesized that the ischemic reperfused (I/R) lung expresses and liberates tumor necrosis factor-alpha (TNF-alpha) to injure the nonischemic lung, and that a TNF-alpha-converting enzyme inhibitor (TACEI) prevents injury of the nonischemic lung by blocking TNF-alpha liberation from the I/R lung. In isolated ventilated rat lungs in which differential perfusion to the right (RL) or left (LL) lung was feasible, LLs were selectively made ischemic (60 min) while maintaining perfusion to RLs, then reperfused (30 min) in a nonrecirculating manner with buffer solution (non-R; n = 18) or in a recirculating manner with buffer containing TACEI (TACEI[+]; n = 18) or without TACEI (TACEI[-]; n = 18). Ischemia reperfusion induced TNF-alpha messenger RNA expression in the ischemic LLs; the expression was highest in TACEI(+) group (P < 0.01). The expression of TNF-alpha, which was detected as immunofluorescence signals on CD34-positive endothelial cells, was observed in ischemic LLs; the highest expression being that in the TACEI(+) group. Wet/dry ratio and protein content in bronchoalveolar lavage fluid were higher in LLs than in RLs, and among the RLs, these 2 parameters were significantly increased in the TACEI(-) group (P < 0.01) in which the RLs were exposed to the TNF-alpha-rich perfusate. On the other hand, protein content in bronchoalveolar lavage fluid of the TACEI(+) group in which RLs were exposed to recirculating perfusate containing little TNF-alpha was decreased to a level close to but still higher than that in the non-R group (P < 0.05). The unilateral I/R lung affected the permeability of the nonischemic lung by liberating mainly TNF-alpha and induced TNF-alpha, interleukin (IL)-1beta, IL-6, and IL-10 messenger RNA expression in the nonischemic lung. These findings support the idea of organ-organ interaction in which an injured organ affects a remote organ by liberating humoral mediators.  相似文献   
78.
To determine brain plasticity changes due to resective epilepsy surgery in children, we performed a longitudinal connectome analysis on the pattern of axonal connectivity in the contralateral hemisphere. Pre‐ and postoperative diffusion tensor imaging (DTI) data were acquired from 35 children with intractable focal epilepsy. A total of 54 brain regions of interest (ROIs) were generated in the hemisphere contralateral to the resection. Within a 54 × 54 connectivity matrix, a pairwise connectivity score was calculated for each connection between two ROIs, based on the DTI fiber streamline number in each connection. A permuted Spearman's ρ‐rank analysis was used to identify specific inter‐regional connections showing a significant association between the postoperative change of connectivity score and clinical variables. Nineteen connections in the contralateral hemisphere showed postoperative increases in the strength of connectivity. Postoperative increase in connectivity between insular–inferior frontal operculum regions as well as that between superior frontal orbital and mid frontal orbital regions were both significantly associated with a larger surgical resection volume (ρ > +0.40) and a younger patient age (ρ > ?0.34). These increases were more robust in patients with frontal resection and in those achieving seizure freedom. Neuropsychological evaluation on subsets of patients revealed that such increases in connectivity were associated with preserved or improved cognitive functions such as visual memory and planning. Resective epilepsy surgery may lead to increased contralateral axonal connectivity in children with focal epilepsy. Our data lead to a hypothesis that such increased connectivity may be an imaging marker of postoperative brain plasticity to compensate for cognitive function. Hum Brain Mapp 37:3946–3956, 2016. © 2016 Wiley Periodicals, Inc.  相似文献   
79.
. Background: To describe computed tomographic (CT), magnetic resonance (MR), ultrasonographic (US), and angiographic findings of retroperitoneal malignant mesenchymoma with emphasis on CT findings. Methods: Five CT, four US, four angiography, and two MR studies were obtained in five patients with pathologically proven retroperitoneal malignant mesenchymoma. Results: Tumors were larger than 10 cm (n = 4), well-cimcumscribed and heterogeneous (n = 4), and with massive intratumorous calcifications (n = 3) on plain CT or US. Tumors showed heterogeneous enhancement on contrast-enhanced CT scans (n = 4) and moderate hypervascularity with heterogeneous staining on angiography (n = 3). Tumors were essentially hypointense on T1-weighted MR images (n = 2) and heterogeneous hyperintense on T2-weighted MR images (n = 2). Plain CT showed a fat-dense structure in a tumor in one patient. Conclusions: The radiologic findings of large expansile heterogeneous masses in the retroperitoneum, especially with massive calcifications, were considered to be typical of malignant mesenchymomas.   相似文献   
80.
Human activities often involve hand‐motor responses following external auditory–verbal commands. It has been believed that hand movements are predominantly driven by the contralateral primary sensorimotor cortex, whereas auditory–verbal information is processed in both superior temporal gyri. It remains unknown whether cortical activation in the superior temporal gyrus during an auditory–motor task is affected by laterality of hand‐motor responses. Here, event‐related γ‐oscillations were intracranially recorded as quantitative measures of cortical activation; we determined how cortical structures were activated by auditory‐cued movement using each hand in 15 patients with focal epilepsy. Auditory–verbal stimuli elicited augmentation of γ‐oscillations in a posterior portion of the superior temporal gyrus, whereas hand‐motor responses elicited γ‐augmentation in the pre‐ and postcentral gyri. The magnitudes of such γ‐augmentation in the superior temporal, precentral, and postcentral gyri were significantly larger when the hand contralateral to the recorded hemisphere was required to be used for motor responses, compared with when the ipsilateral hand was. The superior temporal gyrus in each hemisphere might play a greater pivotal role when the contralateral hand needs to be used for motor responses, compared with when the ipsilateral hand does. Hum Brain Mapp, 2010. © 2010 Wiley‐Liss, Inc.  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