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   2711篇
  免费   162篇
  国内免费   24篇
耳鼻咽喉   22篇
儿科学   52篇
妇产科学   31篇
基础医学   394篇
口腔科学   91篇
临床医学   264篇
内科学   412篇
皮肤病学   34篇
神经病学   250篇
特种医学   134篇
外科学   532篇
综合类   18篇
一般理论   1篇
预防医学   211篇
眼科学   92篇
药学   179篇
中国医学   4篇
肿瘤学   176篇
  2024年   3篇
  2023年   18篇
  2022年   73篇
  2021年   121篇
  2020年   52篇
  2019年   65篇
  2018年   70篇
  2017年   81篇
  2016年   89篇
  2015年   79篇
  2014年   136篇
  2013年   151篇
  2012年   221篇
  2011年   221篇
  2010年   135篇
  2009年   106篇
  2008年   181篇
  2007年   187篇
  2006年   163篇
  2005年   155篇
  2004年   136篇
  2003年   137篇
  2002年   115篇
  2001年   22篇
  2000年   11篇
  1999年   17篇
  1998年   16篇
  1997年   16篇
  1996年   11篇
  1995年   6篇
  1993年   5篇
  1992年   8篇
  1991年   5篇
  1990年   5篇
  1989年   7篇
  1988年   6篇
  1987年   3篇
  1986年   8篇
  1985年   5篇
  1983年   5篇
  1982年   3篇
  1977年   3篇
  1976年   2篇
  1975年   2篇
  1973年   2篇
  1972年   4篇
  1971年   2篇
  1970年   9篇
  1969年   4篇
  1960年   2篇
排序方式: 共有2897条查询结果,搜索用时 15 毫秒
31.
32.
33.
We report a case of a one-year-old boy who was referred to our clinic suspected of having acute abdomen. On physical examination, the abdomen was soft, diffusely tender with weak peristalsis. Ultrasonography and MRI of the right hemiabdomen demonstrated a well-defined, solid, expansive formation with slightly lobulated contours and an interspersed inhomogeneous structure with overall dimensions of 59?×?45?×?50?mm. After midline laparotomy was performed, a cystic tumor was found, twisted around a pedicle which was arising from the falciform ligament and it measured 5–6?cm in diameter. The tumor appeared to be necrotic. The mass was ligated and extirpated on the pedicle and sent for histopathological analysis. After the surgery, the boy was hemodynamically stable, without respiratory complications and all laboratory findings were within normal limits. Histopathological analysis showed that the tumor was composed of mesenchymal stroma with sparse glimpses of hepatocytes and bile ducts with partly cystic changes lined by orderly epithelium. Given the clinical data, histology and immunohistochemistry analysis (alpha-fetoprotein, CK8/18, hepatocyte, desmin and CD31) a diagnosis of a twisted mesenchymal hamartoma of the liver was made.  相似文献   
34.
35.
Primary percutaneous coronary intervention (PCI) is currently viewed as the preferred reperfusion strategy in patients with ST-elevation acute myocardial infarction (STEMI). This method was introduced in our hospital in 2000. From January 1, 2000, to December 31, 2004, a total of 2,393 consecutive patients with STEMI were admitted (27% transferred from 9 non-PCI hospitals and 31 prehospital emergency units/outpatient clinics). Of these patients, 1,666 (70%) underwent urgent coronary angiography and primary PCI. Platelet glycoprotein llb/llla inhibitors were used in 40% and stent placement, in 78%. Postprocedural Thrombolysis In Myocardial Infarction (TIMI) 3 flow was documented in 86%. Intra-aortic balloon counterpulsation was used in 6%; mechanical ventilation, in 8.6%; and inotropic drugs/vasopressors, in 15.8%. Mortality rates in patients with Killip's class I or II ranged from 1% to 4.9% without negative influence of ischemic time. In patients with Killip's class III or IV, mortality rates increased from 18% to 54% with increasing ischemic delay up to 6 hours (p = 0.06) and remained at around 40% afterward. Independent predictors of mortality were age (odds ratio [OR] 1.29, 95% confidence interval [CI] 1.01 to 1.64, p = 0.04), resuscitated cardiac arrest (OR 2.44, 95% CI 1.18 to 5.05, p = 0.02), and postprocedural TIMI flow (OR 0.31, 95% CI 0.16 to 0.59). Overall mortality rates of patients who underwent a primary PCI strategy from 2000 to 2004 were significantly lower than in the control group of 152 consecutive patients who underwent thrombolysis from 1995 to 1996 (6.2% vs 16.4%; p <0.001). In conclusion, introduction of a primary PCI strategy significantly decreased hospital mortality in our unselected group of patients with STEMI compared with the thrombolytic era. Our study further emphasized the importance of shortening myocardial ischemic time, particularly in the presence of severe heart failure on admission.  相似文献   
36.
37.
Hepatobiliary cystadenomas and cystadenocarcinomas are rare tumors. Differentiating between these tumors and benign hepatic cysts may be difficult. Because of their rarity, diagnosis is often delayed and may result in inaccurate treatment, resulting in unnecessary morbidity and mortality. The purpose of this report is to draw attention to these entities and their complications. We report on two cases with spontaneous rupture of hepatobiliary cystadenoma and cystadenocarcinoma cysts, initially treated as simple hepatic cysts by aspiration, or by aspiration combined with sclerotherapy. The spontaneous rupture of the cysts appeared years after the initial treatment of the cysts, leading in one case to a prolonged stay in an intensive care unit. In both cases, a formal liver resection was carried out and microscopic investigations revealed a mucinous cystadenocarcinoma and cystadenoma. In conclusion, although hepatobiliary cystadenomas and cystadenocarcinomas are rare findings, they should not be forgotten in the diagnostic workshop when examining patients with hepatic cysts. If hepatobiliary cystadenomas and cystadenocarcinomas cannot be excluded following radiological imaging, surgery is recommended.  相似文献   
38.
This report compares the cumulative efficacy of cardioversion and skeletal muscle injury after either damped sine wave monophasic or truncated exponential biphasic transthoracic cardioversion of persistent atrial fibrillation. The trial sought to refute the null hypothesis of therapeutic equivalence between monophasic and biphasic waveforms. Results of the study reveal similar cumulative efficacy of waveforms and greater levels of skeletal muscle damage when patients are younger and male, and when monophasic waveforms are used.  相似文献   
39.
40.
Purpose: The purpose of this study was to investigate in vivo antitumor activity of newly synthesized N-sulfonylpyrimidine derivatives 1-(p-toluenesulfonyl)cytosine (4H), 1-(p-toluenesulfonyl)cytosine hydrochloride (4H×HCl) and zinc(II) complex of 1-(p-toluenesulfonyl)cytosine (4K). Materials and methods: In order to do that we have used mouse anaplastic mammary carcinoma (AMCa). Tumor cells (106) in a volume of 0.02 ml were transplanted into the thigh of the right hind leg of CBA mice. All compounds were dissolved in distilled water immediately before injecting to animals. Results: Antitumor effect of these compounds depends on drug doses and time interval between tumor transplantation and drug application. Further the efficacy of these compounds depends on number of drug injections, i. e. whether drug was given in single or in multiple doses. Multiple doses of 400 mg/kg of 1-(p-toluenesulfonyl)cytosine (4H) showed good antitumor effect when applied on day 1, 3, 5, 7 and 9 after tumor transplantation. Still good but slightly lower antitumor effect was also achieved when that compound was given in a single dose (1,200 mg/kg) on day 1 after tumor transplantation. The longest period of tumor growth time was obtained after application of 1-(p-toluenesulfonyl)cytosine hydrochloride (4H×HCl) given as a single dose (300 mg/kg) on day 1 or on day 6 after tumor implantation. However, antitumor effect of zinc(II) complex of 1-(p-toluenesulfonyl)cytosine (4K) was very strong when 300 mg/kg was given on day 1 or day 6, while this effect was slightly lower when drug (200 mg/kg/inj) was given on day 1, 3, 5, 7 and 9 or on day 6, 8, 10, 12 and 14. Conclusion: In this work it has been found that N-1-sulfonylcytosine derivatives have strong antitumor activity against mouse mammary carcinoma which is a good reason for further research of these compounds both in experimental and preclinical studies.  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