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   16917篇
  免费   786篇
  国内免费   109篇
耳鼻咽喉   225篇
儿科学   234篇
妇产科学   180篇
基础医学   2099篇
口腔科学   307篇
临床医学   1178篇
内科学   4516篇
皮肤病学   384篇
神经病学   1133篇
特种医学   783篇
外国民族医学   1篇
外科学   2581篇
综合类   66篇
一般理论   3篇
预防医学   391篇
眼科学   463篇
药学   1092篇
中国医学   42篇
肿瘤学   2134篇
  2023年   105篇
  2022年   227篇
  2021年   362篇
  2020年   212篇
  2019年   281篇
  2018年   374篇
  2017年   292篇
  2016年   322篇
  2015年   369篇
  2014年   476篇
  2013年   552篇
  2012年   916篇
  2011年   955篇
  2010年   582篇
  2009年   524篇
  2008年   942篇
  2007年   984篇
  2006年   991篇
  2005年   958篇
  2004年   1036篇
  2003年   978篇
  2002年   990篇
  2001年   398篇
  2000年   350篇
  1999年   348篇
  1998年   234篇
  1997年   180篇
  1996年   161篇
  1995年   142篇
  1994年   130篇
  1993年   123篇
  1992年   218篇
  1991年   204篇
  1990年   206篇
  1989年   187篇
  1988年   195篇
  1987年   132篇
  1986年   130篇
  1985年   149篇
  1984年   110篇
  1983年   81篇
  1982年   54篇
  1981年   47篇
  1980年   53篇
  1979年   70篇
  1978年   56篇
  1975年   42篇
  1971年   39篇
  1970年   40篇
  1969年   40篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
We describe our methods and outcomes of multidisciplinary treatments in patients with unresectable hilar cholangiocarcinoma. Fifty‐seven patients with a known outcome were enrolled. Thirty‐four of 57 patients were treated and evaluated by salvage therapy. For salvage therapy, we used internal and external radiotherapy, photodynamic therapy, YAG laser therapy and microwave coagulation therapy. The median survival time was 548 days for the group receiving salvage therapy and 198 days for the group not receiving this treatment. In conclusion, although no randomization of the patients was performed in this retrospective study, our present data provide convincing evidence that salvage therapy is a useful therapeutic approach for unresectable hilar cholangiocarcinomas.  相似文献   
2.
Few studies have demonstrated the optimal usage of common inflammatory markers, alone or in combination, based on the cost-effectiveness. We analyzed the yield and cost of C-reactive protein (CRP), white blood cell count (WBC), erythrocyte sedimentation rate (ESR), sialic acid, and protein fractionation in 177 new primary care outpatients with inflammation-related symptoms. A useful result (UR) was assigned if tests contributed to a change in physician's diagnosis or decision-making. Costs of testing were calculated based on either single or simultaneous measurement. Five inflammatory markers generated 147 URs in 123 patients. CRP showed the best contribution to generation of UR, followed by sialic acid, protein fractionation, WBC, and ESR. CRP demonstrated poor correlation with WBC (r = 0.458), while sialic acid strongly correlated with total absolute amount of alpha1 and alpha2 fractions in protein fractionation (r = 0.855) and moderately with ESR (r = 0.651). The combination of CRP and WBC produced the best cost-effectiveness at a cost of Yen 1169 (US dollars 9.6 or Euro 9.7)/additional UR against CRP testing alone. Sialic acid, an automated multichannel analyzer-based test, demonstrated the favorable cost-effectiveness over ESR or protein fractionation when combined with CRP (and WBC). Our results indicate that the optimal usage of these inflammatory markers should involve careful cost-effectiveness considerations.  相似文献   
3.
Background: Gastrointestinal stromal tumors (GIST) are one of the most common mesenchymal tumors of the gastrointestinal tract. GIST are defined by positive immunohistochemical staining for KIT or CD34 and thus are generally diagnosed after surgery. Because small GIST are rarely diagnosed before surgery, the clinical course of these small tumors is not clear. The aim of the present study was to follow changes in size and configuration of small GIST that were pathologically confirmed using endoscopic ultrasonography‐guided fine‐needle aspiration biopsy (EUS‐FNAB). Methods: Between July 1997 and December 2003, 16 tumors in 16 patients (10 men and 6 women) with an immunohistochemical diagnosis of GIST were regularly followed in our hospital. The median patient age when EUS‐FNAB was performed was 62 years (range 26–82 years) and the median follow‐up period was 4.9 years (range 0.5–9.6 years). Results: Fourteen tumors showed no remarkable changes in size and shape during follow up compared with the initial diagnosis. Two tumors enlarged: one tumor approximately doubled its diameter in 8 years and the other tumor increased from 1.8 cm at diagnosis to up to 10 cm after only 2 years. Doubling time of the latter tumor was calculated as 3.1 months. Conclusions: We conclude that EUS‐FNAB might be a good modality for final diagnosis of GIST without surgery, and that GIST without rapid growth on follow up can be endoscopically followed.  相似文献   
4.
We report a case of biliary cystadenocarcinoma which recurred 41 months postoperatively. A 60-year-old woman was admitted for further examination of multiple metastatic tumors and a large amount of ascites. Systemic administration of 5FU and CDDP caused her CEA level to decrease gradually and abdominal computed tomography revealed considerable reduction of the metastatic tumors and ascites. Since her general condition had improved, chemotherapy was continued in the outpatient clinic.  相似文献   
5.
Inter-individual variations in the development of silicosis, even within the same environments, have been reported, which suggest the contribution of genetic factors in silicosis aetiology. The aim of the present study was to determine whether there is any significant genetic influence on the development of silicosis. Furthermore, which genetic loci are responsible for the pulmonary response to silica exposure? Eight strains of inbred mice were used to examine the genetic influence on the lung fibrotic response to silica exposure. After intercross-breeding between the most susceptible and most resistant strains, a genome-wide linkage analysis of quantitative trait loci (QTL) was performed. Hydroxyproline was applied as an index, and genotypes of 167 marker genes were analysed by fragment analysis using a capillary-type sequencer. There was significant inter-strain difference in the mean concentration of hydroxyproline contents among the eight strains of mice. Breeding studies were conducted between the most susceptible, C57BL/6J, and the most resistant strain, CBA/J. A genome-wide linkage analysis of silica-exposed intercrossed cohorts identified significant QTL on chromosome 4 and suggestive QTL on chromosomes 3 and 18. The present study demonstrates that genetic factors may play a significant role in fibrotic-lung responses to silica; one significant and two suggestive quantitative trait loci were identified.  相似文献   
6.
Acute tendon rupture of the extensor pollicis longus (EPL) is rare. We present acute EPL tendon rupture associated with avulsed fracture of the second metacarpal at the insertion of extensor carpi radialis longus. Tendon rupture of the EPL was repaired with end-to-end suture and avulsed fracture of the second metacarpal base was treated with open reduction and internal fixation.  相似文献   
7.
We report on a Thai family with dominantly inherited malformation syndrome with upper limb anomalies, short stature, quadricuspid aortic valve, and minor craniofacial anomalies. The affected individuals comprised a mildly affected mother, a moderately affected daughter, and a most severely affected son. The daughter and son had short stature. The craniofacial abnormalities comprised frontal bossing, hypoplastic nasal bones, depressed nasal bridge, and broad nasal alae. The upper limb defects varies among the patients, ranging from radial ray defects in the mother through radial and ulnar ray defects with unilateral humeral hypoplasia in the daughter to radial ray defects with severe oligodactyly and bilateral humeral hypoplasia in the son. All patients in this family had hypoplasia of the shoulder girdle and resembled what is observed in many families with Holt‐Oram syndrome. Moreover, the son showed quadricuspid aortic valve with mild aortic regurgitation. However, the present family did not show any mutation of the TBX5 gene, a disease‐causing gene of Holt‐Oram syndrome. The present family deserves further investigation on other genes that play a role in the development of the upper limbs, particularly of radial rays. © 2002 Wiley‐Liss, Inc.  相似文献   
8.
A case of Ullrich disease was presented. The patient was a 3-year-old girl with torticollis, generalized muscle weakness and acroatonia since birth. High-arched palate, protruded calcaneus, and mild contracture of proximal joints were also recognized. Intellectual development was normal. Serum level of CPK was slightly increased. In histological and histochemical examinations of quadriceps femoris muscle, proliferated connective tissue, marked variation in the muscle fiber diameter, and a lot of degenerated and regenerated fibers were recognized. Minimal injury easily causes subcutaneous hemorrhage, but no abnormality was found in the structure of collagen.  相似文献   
9.
Ultrasonotomograms of 22 kidneys were obtained in 11 patients with renal-acute renal failure (renal-ARF). The underlying diseases of renal-ARF were acute tubular necrosis in 8 patients and acute on-set chronic glomerulonephritis in 3 patients. They were treated by hemodialysis in 10 patients and intermittent peritoneal dialysis in 1 patient. Ultrasonic measurement of the size of kidneys revealed that the thickness (anterior-posterior diameter) and the ratio of thickness to length (T/L) were greater in patients with ARF than in those with chronic renal failure and normal renal function. The patients with a low value of T/L (under 0.60) had a significantly greater urine volume than those with high a value of T/L (0.60 or more). The sonographic features of renal-ARF kidneys were marked increase in parenchymal echogenicity and appearance of hypoechoic swollen renal pyramids with sharpness of the corticomedullary border. In the course of ARF, these sonographic changes gradually disappeared when the patients had recovered from ARF. However, the prognosis was poor in patients with severer sonographic findings. We believe that repeated ultrasonic examination of the kidneys in patients with renal-ARF is useful for not only differential diagnosis of post-renal urinary obstruction but evaluating the course of ARF.  相似文献   
10.
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