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   1579篇
  免费   57篇
  国内免费   4篇
耳鼻咽喉   2篇
儿科学   38篇
妇产科学   26篇
基础医学   117篇
口腔科学   16篇
临床医学   85篇
内科学   290篇
皮肤病学   23篇
神经病学   85篇
特种医学   21篇
外科学   674篇
综合类   18篇
预防医学   37篇
眼科学   28篇
药学   64篇
中国医学   2篇
肿瘤学   114篇
  2023年   15篇
  2022年   11篇
  2021年   20篇
  2020年   13篇
  2019年   25篇
  2018年   18篇
  2017年   13篇
  2016年   15篇
  2015年   21篇
  2014年   11篇
  2013年   25篇
  2012年   26篇
  2011年   41篇
  2010年   31篇
  2009年   26篇
  2008年   37篇
  2007年   32篇
  2006年   41篇
  2005年   48篇
  2004年   36篇
  2003年   63篇
  2002年   75篇
  2001年   68篇
  2000年   69篇
  1999年   95篇
  1998年   43篇
  1997年   32篇
  1996年   35篇
  1995年   22篇
  1994年   20篇
  1993年   16篇
  1992年   67篇
  1991年   60篇
  1990年   49篇
  1989年   53篇
  1988年   53篇
  1987年   48篇
  1986年   48篇
  1985年   42篇
  1984年   39篇
  1983年   14篇
  1982年   6篇
  1979年   13篇
  1978年   9篇
  1977年   14篇
  1976年   5篇
  1974年   8篇
  1973年   5篇
  1968年   5篇
  1954年   5篇
排序方式: 共有1640条查询结果,搜索用时 15 毫秒
1.
2.
Laparoscopic surgery has several advantages over traditional surgery because it has been shown to be less invasive. The next logical step in the evolution of minimally invasive surgery may be to eliminate all abdominal incisions. The natural orifices provide a port of entry via the gastrointestinal tract to the peritoneal cavity. This approach would require the creation of a perforation, which is considered to be a major complication of endoscopy with significant morbidity and mortality. However, there are several recent studies that have described the technical feasibility and safety of a per‐oral transgastric approach to the peritoneal cavity using conventional endoscopes. Theoretically, this approach could reduce postoperative abdominal wall pain, wound infection, hernia formation, and adhesions. This article aims to summarize the current status of transgastric surgery, currently referred to as natural orifice transluminal endoscopic surgery (NOTES), and to address some of its future challenges.  相似文献   
3.
St. Jude Medical valve replacement was performed in 1,039 patients; 320 had aortic (AVR), 543 mitral (MVR), and 176 had double valve replacement (DVR). There were 44(4.2%) early deaths. Follow-up extended in 995 patients from 10 to 130 months, with a cumulative period of 2,730 patients-years. The overall survival rates of AVR, MVR, and DVR patients at 10 years were 60.5%, 89.6%, 90.3% respectively. The linearized incidences of valve thrombosis, thromboembolism, anticoagulation-related hemorrhage, prosthetic valve endocarditis, and significant hemolysis were as follows: 0.11%/pt-yr, 1.33%/pt-yr, 0.04%/pt-yr, 0.18%/pt-yr, and 0.11%/pt-yr, respectively. There were no structural failure after 10 years follow-up. Reoperation (explant and re-replacement or suture repair) was required in 10 patients. Seven of them had periprosthetic leakage, 2 had valve thrombosis, and one underwent reoperation because of a technical error. Actuarially over 98% of patients were free of valve-related mortality at 10 years. St. Jude Medical valve is an excellent alternative for use in the surgical treatment of valvular heart disease.  相似文献   
4.
Hypospadias   总被引:1,自引:0,他引:1  
  相似文献   
5.
We retrospectively reviewed 38 patients with primary penile squamous cell carcinoma (stage 1 in 22, stage 2 in 7 and stage 3 in 9) who were treated in our institution from 1963 through 1987. The incidence of regional nodal metastasis was correlated with tumor category, local infiltration and tumor grade. The incidence rate of nodal metastasis of G2 and G3 tumors was statistically higher than that of G1 tumors. Of 27 patients initially treated by radiotherapy and/or chemotherapy, 11 patients achieved complete response. G1 tumors and T1 to 2 tumors had such high response rates as 58 and 50 per cent, respectively, but 5 patients (45 per cent) had local recurrence at an average of 74 months after initial treatment. The 5-year survival rates of over-all, stage 1, 2 and 3 were 73, 90, 75 and 25 per cent, respectively. Patients with stage 3 disease had a statistical lower survival rate than those with stage 1 or 2 disease. Among 13 patients with regional nodal metastasis, none with G2 tumor survived three years, although 3 patients (60 per cent) of those with G1 tumor survived five years. These results suggest that tumor grade is the most prognostic factor for the regional nodal metastasis, the response of conservative treatment and the survival of metastasized patients.  相似文献   
6.
7.
We experienced 5 cases of acute renal failure due to rhabdomyolysis during the last two years and investigated those etiologies. Diagnosis of rhabdomyolysis was established by the detection of elevated serum creatine phosphokinase, myoglobin, aldolase, myoglobinuria as well as by the clinical course. The respective underlying illness of the 5 cases were grand mal seizures, infection (high fever), heat stroke, diabetes mellitus with hyperosmolar nonketotic coma and cerebral infarction treated by barbiturate. In this investigation, however, any single cause was not enough as the etiologies of rhabdomyolysis. There were multiple factors responsible to rhabdomyolysis in each case, such as hypokalemia, hypophosphatemia, shock, arteriosclerosis, etc. Some cases could not be classified as traumatic or non-traumatic rhabdomyolysis. Thus, in one case, acute renal failure due to rhabdomyolysis induced by the combination of grand mal seizures and serum potassium/phosphate depletion. 2 cases recovered without hemodialysis. 3 cases died in multiple organ failure, included a case treated by hemodialysis. We conclude that acute renal failure due to rhabdomyolysis induced easily by numerous diseases and early diagnosis is recommended.  相似文献   
8.
The usefulness of an ultrasonic duplex system to assess portal blood flow was investigated. In a model involving a steady flow through a vinyl tube in agar, there was a significant linear correlation between the maximum blood flow velocity measured by this system (V-max) and the mean blood flow velocity calculated from the actually measured blood flow volume (V-mean), that is, V-mean = 0.53 X V-max was obtained (r = 0.994; n = 47). This equation was used to calculate the mean portal blood flow velocity by this system (V-dopp) in 10 patients with liver disease, and the findings were compared with data simultaneously obtained by cineangiographic mapping of Lipiodol droplets released into the portal vein through a catheter placed in situ at the time of surgery (V-cine). A linear correlation between V-dopp and V-cine was statistically significant (r = 0.970; n = 13), and the regression line was V-cine = 1.29 X V-dopp -2.11. The ultrasonic duplex system proved reliable for a quantitative assessment of portal hemodynamics.  相似文献   
9.
Abstract: The plasma ratio of each neutral amino acid (tryptophan (TRP), tyrosine (TYR), valine, isoleucine, leucine (LEU) or phenylalanine) to the sum of the other neutral amino acids was measured in 16 : manic and 14 : depressed patients. In the manics, there was a correlation between the psychomotor activity and the plasma TRP and LEU ratios. In the depressives, the depressed mood, retardation and global severity were correlated with the TRP ratio. The zotepine responders showed an increase in the TRP ratio after treatment. In the mianserin responders, the TYR ratio, which was high before the treatment, decreased to the normal range after the treatment. But, the plasma amino acid ratios remained unchanged in the patients treated with lithium carbonate or amitriptyhe. These results suggest that, in manic-depressive illness, there might be abnormalities in the metabolism of neutral amino acids, mainly of TRP and TYR, and that the plasma TRP and TYR ratios might be important indicators for determining the efflcacy of some drugs.  相似文献   
10.
Intra-operative and postoperative endoscopy were used in 16 patients with portal hypertension to investigate whether intra-operative elimination of oesophageal varices by oesophageal transection with devascularization leads to prevention of variceal recurrence and rebleeding. Intra-operative elimination of the varices was achieved in 12 patients. In ten patients the varices recurred and in two cases rebled, during the follow-up period of 6-43 months (average 25 months). Of the ten patients with recurrent varices, eight (including the two who bled acutely in the postoperative period) successfully underwent endoscopic injection sclerotherapy. Postoperative endoscopy was performed at 5-monthly intervals. It is concluded that intra-operative elimination of the varices will not prevent recurrence and that a closer follow-up using endoscopy more than three times a year is a significant aid in the management of these patients.  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