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   1665篇
  免费   114篇
  国内免费   19篇
耳鼻咽喉   3篇
儿科学   31篇
妇产科学   21篇
基础医学   214篇
口腔科学   58篇
临床医学   80篇
内科学   592篇
皮肤病学   131篇
神经病学   100篇
特种医学   37篇
外科学   275篇
预防医学   20篇
眼科学   3篇
药学   76篇
中国医学   4篇
肿瘤学   153篇
  2023年   9篇
  2022年   16篇
  2021年   24篇
  2020年   25篇
  2019年   33篇
  2018年   39篇
  2017年   30篇
  2016年   38篇
  2015年   30篇
  2014年   51篇
  2013年   55篇
  2012年   97篇
  2011年   136篇
  2010年   68篇
  2009年   45篇
  2008年   89篇
  2007年   135篇
  2006年   120篇
  2005年   130篇
  2004年   115篇
  2003年   111篇
  2002年   113篇
  2001年   26篇
  2000年   25篇
  1999年   19篇
  1998年   29篇
  1997年   29篇
  1996年   27篇
  1995年   18篇
  1994年   7篇
  1993年   8篇
  1992年   7篇
  1991年   9篇
  1990年   12篇
  1989年   10篇
  1988年   17篇
  1987年   3篇
  1986年   4篇
  1985年   6篇
  1984年   4篇
  1983年   5篇
  1981年   1篇
  1980年   4篇
  1979年   3篇
  1978年   6篇
  1977年   4篇
  1976年   1篇
  1975年   1篇
  1974年   2篇
  1969年   2篇
排序方式: 共有1798条查询结果,搜索用时 31 毫秒
1.
2.
Thirty-seven patients with primary aldosteronism were treated by unilateral total adrenalectomy during a 7-year period (1981–1987). The 37 patients were classified into 3 groups on the basis of adrenal pathology: unilateral solitary adenoma, 23 cases (group 1); unilateral adenomas, 3 cases (group 2); and adenoma with multiple macro- or microscopic nodules, 11 cases (group 3). The preoperative conditions of the patients (age, duration of hypertension, plasma renin activity, plasma aldosterone concentration, and serum potassium concentration), postoperative sequential changes of hormone levels, and outcome of hypertension were compared among the groups in order to determine whether the differences of adrenal pathology would affect the postoperative course. The preoperative parameters excluding age at surgery did not differ significantly among the 3 groups. The mean age in group 3, however, was slightly higher than in groups 1 and 2 (47.8 versus 42.8 versus 42.7 years). Postoperative hormonal changes were also similar, particularly in groups 1 and 3, staying within the normal range throughout the follow-up period (mean, 31 months; range, 3–86 months). However, postoperative improvement of hypertension showed marked differences, being significantl retarded in patients with multinodular lesions (group 3), about half of whom remained hypertensive even after 1 year. Nodular lesions other than adenoma(s) were, therefore, thought not to contribute to hormonal excess but to result from intractable hypertension.
Resumen Treinta y siete pacientes con aldosteronismo primario fueron tratados mediante adrenalectomía total unilateral en un período de 7 años (1981–1987). Los 37 pacientes fueron clasificados en 3 grupos con base en la patología adrenal: adenoma solitario unilateral, 23 casos (grupo I); adenomas unilaterales, 3 casos (grupo 2); y adenoma con múltiples macro-o micronódulos, 11 casos (grupo 3). Las condiciones preoperatorias de los pacientes (edad, duración de la hipertensión, actividad de renina plasmática, concentración plasmática de aldosterona, y concentración sérica de potasio), los cambios postoperatorios secuenciales en los niveles hormonales, y el resultado de la hipertensión fueron comparados en los 3 grupos, con el objeto de determinar si las diferencias en la patología adrenal podrían afectar la evolución postoperatoria. Los parámetros preoperatorios, excluyendo la edad en el momento de la cirugía, no diferieron significativamente en los 3 grupos. La edad promedio en el grupo 3, sin embargo, fue ligeramente superior en los grupos 1 y 2 (47.8 versus 42.8 versus 42.7 años).Los cambios hormonales postoperatorios también fueron similares, particularmente en los grupos 1 y 3, manteniéndose dentro del rango normal a través del seguimiento (promedio, 31 meses; rango, 3–86). Sin embargo, la mejoría postoperatoria de la hipertensión exhibió diferencias marcadas, con aparación significativamente tardía en pacientes con lesiones nodulares (grupo 3); aproximadamente la mitad de éstos permanecieron hipertensos aún después de un año. Por consiguiente, se piensa que las lesiones nodulares diferentes del adenoma(s) no contribuyen al exceso hormonal sino que resultan de la hipertensión intratable.

Résumé Trente-sept patients ayant un hyperaldostéronisme primaire ont eu une surrénalectomie totale unilatérale entre 1981 et 1987. Ces 37 patients ont été classés en 3 groupes selon la pathologie surrénalienne: adénome solitaire unilatéral, 23 cas (groupe 1); adénome unilatéral, 3 cas (groupe 2); et adénome avec nodules micro ou macroscopiques multiples, 11 cas (groupe 3). On a comparé les données préopératoires (âge, durée de l'hypertension, activité rénine plasmatique, concentration d'aldostérone plasmatique et kaliémie), les changements hormonaux postopératoires, et l'évolution de l'hypertension afin de déterminer si des différences de pathologie surrénalienne peuvent influencer l'évolution postopératoire. Les paramètres préopératoires (excepté l'âge) ne différaient pas de façon significative parmi les 3 groupes. L'âge moyen était plus élevé dans le groupe 3 que dans les groupes 1 et 2 (47.8 versus 42.8 versus 42.7 ans).Les variations hormonales postopératoires étaient également similaires, surtout dans les groupes 1 et 3, restant dans les limites de la normale pendant la période de suivi (moyenne, 31 mois; extrêmes, 3 à 86 mois). Cependant l'amélioration de l'hypertension postopératoire était différente, retardée de façon significative chez les patients ayant des lésions multinodulaires (groupe 3), la moitié d'entre eux restant hypertendus après un an. Les lésions nodulaires, étant donné que les adénomes ne donnent pas d'hypersécrétion hormonale, peuvent traduire plutôt une hypertension prolongée.


Presented at the International Association of Endocrine Surgeons in Toronto, Ontario, Canada, September, 1989.  相似文献   
3.
Thrombocytopenia is a frequent finding following living donor hepatectomy. It appears more pronounced in right graft donors than in left graft donors. This study analyzed postoperative thrombocytopenia in 20 living liver donors and examined the change of endogenous thrombopoietin (TPO) in its recovery. Platelet count, TPO level, fibrinogen degradation product (FDP), and D-Dimer were measured before surgery and on postoperative days (PODs) 1, 2, 3, 5, 7, and 14. Concurrently, liver and spleen volumes were calculated by computed tomography. Platelet count on POD 3 was significantly lower in right graft donors than in left graft donors (13.0 +/- 3.7 x 10(4)/microL vs. 16.8 +/- 4.0 x 10(4)/microL, P = 0.039) but recovered by POD 7 in all donors. Postoperative elevations of FDP and D-Dimer were significantly higher in right graft donors than in left graft donors. TPO level rose immediately after surgery, peaked on POD 5 in left graft donors and on POD 7 in right graft donors, and fell nearly to preoperative levels by POD 14. Postoperative TPO level per liver volume was significantly higher in right graft donors than in left graft donors. In conclusion, thrombocytopenia following living donor hepatectomy resolved within the first week regardless of graft type and was mainly associated with increasing consumption of circulating platelets, possibly due to intrahepatic and splenic congestion. With a reduced number of circulating platelets, TPO level rapidly increases. Also, with reduced consumption of platelets related to recovery from surgery, thrombocytopenia should resolve. As a consequence, TPO level would be expected to fall.  相似文献   
4.
Prostaglandin E1 (PGE1) has several potential therapeutic effects, including cytoprotection, vasodilation, and inhibition of platelet aggregation. This study investigates the protective action of PGE1 against hepatic ischemia/reperfusion injury in vivo using a complementary DNA microarray. PGE1 or saline was continuously administered intravenously to mice in which the left lobe of the liver was made ischemic for 30 minutes and then reperfused. Livers were harvested 0, 10, and 30 minutes postreperfusion. Messenger RNA was extracted, and the samples were labeled with two different fluorescent dyes and hybridized to the RIKEN set of 18,816 full-length enriched mouse complementary DNA microarrays. Serum alanine aminotransferase and aspartate aminotransferase levels at 180 minutes postreperfusion were significantly lower in the PGE1-treated group than in the saline-treated group. The cDNA microarray analysis revealed that the genes encoding heat-shock protein (HSP) 70, glucose-regulated protein 78, HSP86, and glutathione S-transferase were upregulated at the end of the ischemic period (0 minutes postreperfusion) in the PGE1 group. Our results suggested that PGE1 induces HSPs immediately after ischemia reperfusion. HSPs might therefore play an important role in the protective effects of PGE1 against ischemia/reperfusion injury of the liver.  相似文献   
5.
Abstract: The Self-Rating Body Image (SRBI) test was used to determine whether the patients with eating disorders such as anorexia nervosa or bulimia showed their body image disturbance or not. The SRBI was completed by 120 subjects who consisted of 30 low weight (LW) controls, 30 normal weight (NW) controls, 30 high weight (HW) controls, 18 anorexic patients (AN) and 12 bulimic patients (BN). The AN group had a significantly greater dissatisfaction with the scales of the body shape, visceral organ and face image of the SRBI than the weight-matched LW group. The BN group had a significantly greater dissatisfaction with the visceral organ image than the weight-matched NW group. However, no significant difference in the body shape and face images between the BN and NW groups was found. Our results suggest that the anorexic patients may disturb more parts of the body image than the bulimic patients though both the anorexic and bulimic patients showed the disturbance of body image.  相似文献   
6.
Clinicopathologic studies were performed to establish rational criteria for total thyroidectomy as a treatment of follicular carcinoma. During the 4-year period from 1981 to 1984, total thyroidectomy was carried out on 23 patients in whom unequivocal vascular invasion and/or obvious extracapsular extension were disclosed on pathological study of the primary thyroid lesion. Although occult metastatic lesions were detected postoperatively in 5 patients, no distant metastases have been found in 12. Distant metastasis was clinically manifest on admission in the other 6 patients. The degree of vascular invasion at the primary lesion was not correlated with the occurrence of distant metastasis. However, 10 of the 15 patients with tumors characterized by a thick fibrous capsule had distant metastases, while all but 1 of 8 patients with a thin capsule showed no metastasis. Apparent capsular invasion seemed to increase the relative risk of distant metastasis. On the other hand, solid clusters of tumor cells containing a variable number of small follicles, which characterize Langhans' wuchernde Struma, were found in 6 patients, and 5 of them showed distant metastases. Thus, total thyroidectomy should be considered when (a) distant metastases are clinically apparent, (b) the primary lesion has a thick fibrous capsule with or without obvious capsular invasion, or (c) solid clusters of tumor cells are demonstrated microscopically.
Resumen Se realizaron estudios clinicopatológicos con el propósito de establecer criterios racionales para la tiroidectomía total en el tratamiento del carcinoma folicular. En el curso de un perfodo de 4 anos entre 1981 y 1984, se realizó tiroidectomía total en 23 pacientes en quienes se halló inequívoca invasión vascular y/o obvia extension extracapsular en el examen histopatológico de la lesión tiroidea primaria. Aunque postoperatoriamente se detectaron lesiones metastáticas ocultas en 5 pacientes, no se encontraron metástasis distantes en 12. Metástasis distantes eran clínicamente manifiestas en el momenta de la admisión en los otros 6 pacientes. El grado de invasión vascular en la lesión primaria no apareció correlacionado con la ocurrencia de metástasis distantes. Sin embargo, 10 de los 15 pacientes con tumores caracterizados por una cápsula gruesa y fibrosa tenían metástasis distantes, mientras solo 1 de 8 pacientes con tumores de cápsula fina mostró metástasis. La invasión capsular aparente parece incrementar el riesgo relativo de metástasis distantes. Por otra parte, agrupaciones sólidas de células tumorales con presencia de números variables de folículos pequeños, que caracterizan al wuchernde Struma de Langhans, fueron encontrados en 6 pacientes, 5 de los cuales mostraron metastasis distantes. Por lo tanto, se debe considerar la tiroidectomía total cuando: (a) haya metástasis distantes clínicamente aparentes, (b) la lesión primaria tenga una gruesa cápsula fibrosa con o sin invasión capsular obvia, y (c) se demuestren microscópicamente agrupaciones sólidas de células tumorales.

Résumé Une étude clinicopathologique a été menée pour déterminer les critères de thyroïdectomie totale comme traitement dans le cancer folliculaire de la thyroïde. Pendant 4 ans, de 1981 à 1984, 23 patients ont subi une thyroïdectomie totale pour envahissement vasculaire non équivoque et/ou extension extracapsulaire évidente découverte sur la pièce d'exérèse initiale. Cinq patients avaient des métastases occultes découvertes dans la période postopératoire, 6 avaient des métastases cliniquement évidentes, alors que 12 ne présentaient aucun signe de métastase à distance. Le degré d'envahissement vasculaire de la lésion primitive n'était pas corrélé avec la survenue de métastases à distance. Cependant, 10 des 15 patients à tumeurs caractérisées par un épaississement de la capsule fibreuse avaient des métastases à distance, alors que 7 des 8 patients avec une capsule mince n'avaient pas de métastases. L'envahissement capsulaire était associé à un plus grand risque de métastases à distance. Des amas solides de cellules tumorales contenant de petits follicules, le wuckernde struma de Langhans, étaient retrouvés dans 6 cas, dont 5 avaient des métastases à distance. Ainsi, la thyroïdectomie totale est préconisée lorsque (a) des métastases à distance sont cliniquement évidentes, (b) la lésion primitive possède une capsule fibreuse épaisse avec ou sans envahissement évident, et (c) on met en évidence des cellules tumorales en amas microscopiquement.


Presented at the International Association of Endocrine Surgeons in Sydney, Australia, September, 1987.  相似文献   
7.
Recent studies suggest that the enhanced release of reactive oxygen species (ROS) plays an important role in the pathogenesis of clinical inflammatory bowel diseases (IBD) such as ulcerative colitis and Crohn's disease. In the present study, we investigated the effects of the free radical scavenger edaravone, which is used clinically as an anti-stroke agent, in the development of experimental dextran sulfate sodium (DSS)-induced colitis in rats. The rats were fed 4% (w/w of diet) DSS in standard powder chow for 8 days. The edaravone and vehicle saline were injected subcutaneously twice a day. After the experimental period, the wet colonic weight, macroscopic mucosal damaged area, histological damage score, mucosal myeloperoxidase (MPO) activity, mucosal tissue lipid peroxidate and serum interleukin-6 (IL-6) levels were measured. In the DSS-induced colitis model, edaravone treatment (1-20 mg/kg day) significantly reduced the wet colonic weight, macroscopic damaged area, and the histological damage score. Edaravone treatment also reduced mucosal MPO activity, mucosal tissue lipid peroxidate level and serum IL-6 level. In particular, edaravone at a dose of 20 mg/kg day significantly reduced mucosal MPO activity and serum IL-6 level. These results strongly support the involvement of ROS in the pathogenesis of DSS-induced colitis. A clinical effect for edaravone against IBD patients is strongly expected.  相似文献   
8.
9.
10.
Integrin alphavbeta5 is a receptor for vitronectin, a plasma glycoprotein that is also distributed in extracellular matrix of various tissues. Matrix-bound vitronectin has the potential to stabilize the active form of plasminogen activator inhibitor-1, resulting in the inhibition of the plasmin-mediated pericellular proteolytic cascade. In this study, we compared the levels of alphavbeta5 and matrix-bound vitronectin between normal and scleroderma fibroblasts and investigated the association with fibrosis. We demonstrated that alphavbeta5 was up-regulated on scleroderma fibroblasts. The up-regulated alphavbeta5 contributed to the increase in vitronectin-binding ability in scleroderma fibroblasts, which led to the vitronectin-dependent activation of plasminogen activator inhibitor-1. In immunohistochemistry, the alphav and beta5 subunits were stained strongly on scleroderma fibroblasts and the amount of vitronectin was increased in the pericellular matrix of those cells. The transient overexpression of alphavbeta5 on normal fibroblasts enhanced the human alpha2(I) collagen promoter activity through Sp-1 and Smad3 as well as the vitronectin-dependent plasminogen activator inhibitor-1 activity. This effect on the promoter activity was also observed in the absence of vitronectin and completely disappeared in the presence of anti-alphavbeta5 antibody. These results indicate that the up-regulated alphavbeta5 may contribute to the phenotypical alteration of scleroderma fibroblasts, while at the same time suppressing the plasmin-mediated pericellular proteolytic cascade.  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