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   615575篇
  免费   42923篇
  国内免费   29469篇
耳鼻咽喉   6087篇
儿科学   12830篇
妇产科学   10412篇
基础医学   71391篇
口腔科学   12594篇
临床医学   73624篇
内科学   92429篇
皮肤病学   9196篇
神经病学   32130篇
特种医学   26483篇
外国民族医学   333篇
外科学   67034篇
综合类   79547篇
现状与发展   97篇
一般理论   39篇
预防医学   47185篇
眼科学   16268篇
药学   59285篇
  487篇
中国医学   27205篇
肿瘤学   43311篇
  2023年   6104篇
  2022年   16026篇
  2021年   20534篇
  2020年   16104篇
  2019年   13151篇
  2018年   16950篇
  2017年   16756篇
  2016年   15290篇
  2015年   23734篇
  2014年   27758篇
  2013年   25085篇
  2012年   41877篇
  2011年   40567篇
  2010年   26834篇
  2009年   23772篇
  2008年   26340篇
  2007年   26812篇
  2006年   25790篇
  2005年   32750篇
  2004年   27012篇
  2003年   22198篇
  2002年   15021篇
  2001年   14092篇
  2000年   10923篇
  1999年   15022篇
  1998年   6314篇
  1997年   5865篇
  1996年   4657篇
  1995年   4479篇
  1994年   3744篇
  1993年   2475篇
  1992年   9516篇
  1991年   9379篇
  1990年   9279篇
  1989年   8641篇
  1988年   7855篇
  1987年   7515篇
  1986年   7000篇
  1985年   5968篇
  1984年   3986篇
  1983年   3197篇
  1979年   3995篇
  1978年   2437篇
  1975年   2505篇
  1974年   3155篇
  1973年   2788篇
  1972年   2802篇
  1971年   2765篇
  1970年   2580篇
  1969年   2498篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
AClinicalStudyofReversingLeftVentricularHypertrophyinHypertensivePatientsbyAdalatZhangFumin(张馥敏)XuDi(许迪)YongYonghong(雍永宏)Chen...  相似文献   
82.
本文选择34颗有银汞充填体悬突的患牙,采用金刚砂钻和银汞磨光钻去除悬突,并观察去除悬突前后部分牙周组织的变化、结果表明银汞充填体悬突危害牙周组织的健康.去除悬突并协同口腔卫生宣教、可促进牙周组织的恢复.  相似文献   
83.
Eleven patients with lunatomalacia were treated by excision of the lunate and instillation of liquid silicone. The silicone vulcanised and formed an in-situ molded prosthesis. The patients were reexamined after a mean of 7.1 years. Four patients were pain-free and two had pain only at work; three had not been improved by the operation and two had undergone arthrodesis. The patients with good results all belonged to group IV pre-operatively. Surprisingly, no patient showed any sign of silicone synovitis, although all the prostheses except one had either fractured or deformed. The reasons for this are discussed and the indications for the operation established.  相似文献   
84.
85.
We have investigated anemia in patients at different stages of the evolution of three chronic renal diseases: Balkan endemic nephropathy (BEN), chronic pyelonephritis (PN) and chronic glomerulonephritis (GN). A total of 88 patients with creatinine clearances from 9 to 118 ml/min and hemoglobin concentrations from 70 to 160 g/l were studied with regard to the relationship, if any, between erythropoietin production and the type and stage of nephropathy. Anemia in BEN was a particular focus of interest since it had been stated that in BEN, anemia precedes renal failure. Our data neither prove nor disprove this statement. A significant positive correlation between creatinine clearance and hemoglobin concentration was found in all three nephropathies, indicating that in the patients studied the severity of anemia increased with the impairment of renal function regardless of the underlying disease. Serum levels of immunoreactive erythropoietin were in the normal range in 54 patients, moderately increased in 20 and slightly decreased in 14. The erythropoietin level appears to be unrelated to the stage of renal failure or the type of nephropathy. The only exception was the subgroup where the patients with glomerulonephritis and normal renal function had increased serum erythropoietin levels and significantly higher parameters of red blood cell concentration than the patients from the same subgroup with tubulointerstitial nephropathies. In patients with severe renal failure and anemia, serum erythropoietin levels were inappropriately low for the degree of anemia, indicating that erythropoietin plays a role in the pathogenesis of the anemia.  相似文献   
86.
Excision of the rectum should take in account that the main lymphatic spread follows the cranial route and that dissection of the rectal wall should be performed across its adjacent anatomical lamellae. It is not clear whether an extensive pelvic dissection and high ligature of the inferior mesenteric artery are beneficial. Spontaneous or iatrogenic perforation of the tumour considerable increases the incidence of local recurrence. The frequency of postoperative urinary and sexual dysfunction ranges from 3.5-57% and 14-38% respectively. The reported surgical mortality averages 5-6%.  相似文献   
87.
In 570 patients with sporadic primary hyperparathyroidism, the age, sex, symptoms, and preoperative serum calcium values were related to the histopathologic diagnoses, operative findings, and the extent and outcome of parathyroid surgery. Renal stone formation was especially prevalent in younger patients with slight hypercalcemia and parathyroid chief cell hyperplasia, whereas neuromuscular and psychiatric disturbances were overrepresented among older women with higher serum calcium values. Serum calcium concentration was inversely correlated to the proportional incidence of chief cell hyperplasia and positively correlated to the glandular weight of both adenomas and hyperplasias. Glandular size was markedly irregular in chief cell hyperplasia, with increased gland weights of no more than two glands in 78% of patients. During follow-up, for as long as 27 years, normocalcemia was obtained in 91% of patients with adenomas, with failures mainly depending on difficulties in identifying the parathyroid glands. The rate of normocalcemia was lower (80%) among patients with hyperplasia, but an inability to visualize the glands was not a major cause of failure. In patients with hyperplasia with asymmetric and more markedly enlarged glands, it appeared sufficient to remove only the enlarged glands, whereas the findings advocated a subtotal 3- to 3.5-gland resection in patients with more symmetrically or less enlarged hyperplastic glands.  相似文献   
88.
From 1979 to 1987 1428 patients with blunt abdominal trauma were treated in the Department of Surgery of the University of Freiburg; 119 patients had intestinal injuries. They were mainly young adults who had sustained a car accident. 71.3% of the small bowel injuries were overseen, 14.2% needed resection, and in 14.5% an operative procedure was not necessary. The surgical procedure for colonic injuries has to be chosen with regard to the age and general condition of the patient, to the severity of the trauma, to associated injuries and to the stage of peritonitis. Accordingly, 18% of the patients were treated with and 58% without a protective colostomy, 24% could be treated conservatively. Mortality and morbidity correlated with the severity of associated injuries. Morbidity was also dependent on the time interval between accident and operative therapy.  相似文献   
89.
猕猴桃汁抗环磷酰胺致突变作用的机理   总被引:12,自引:1,他引:11  
目的用大鼠外周血双核淋巴细胞微核测试法(CBMNT),在哺乳动物整体水平,研究猕猴桃汁抗环磷酰胺(CP)的致突变作用以及生物转化Ⅱ相酶的作用。方法测定大鼠外周血双核淋巴细胞微核细胞率及肝组织中总谷胱甘肽硫转移酶(GST)、尿苷二磷酸葡萄糖醛酸转移酶(UDPGT)、谷氨酰胺转肽酶(γGT)活性。结果猕猴桃汁对CP诱发的大鼠外周血双核淋巴细胞微核细胞率有显著抑制作用,能明显诱导大鼠肝脏总GST、UDGTP活性,但对γGT活性无显著影响。大鼠外周血双核淋巴细胞微核细胞率与总GST、UDGTP活性呈明显负相关。结论猕猴桃汁抗CP致微核形成作用的机理可能是通过诱导机体外来化合物代谢解毒酶系,加速CP的代谢灭活  相似文献   
90.
A Brci? 《Hand Clinics》1990,6(2):211-219
The article describes the correct technique of primary tangential excision in deep dermal and third-degree hand burns. The operation performed under tourniquet facilitates the preservation of viable tissue, which is of utmost importance in hand burns. The therapeutic results depend on the extent of destroyed tissue. Primary tangential excision prevents fibrosis due to prolonged infection and impaired circulation, thus creating much more favorable conditions for reconstruction and rehabilitation.  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