全文获取类型
收费全文 | 9927篇 |
免费 | 762篇 |
国内免费 | 204篇 |
专业分类
耳鼻咽喉 | 94篇 |
儿科学 | 374篇 |
妇产科学 | 325篇 |
基础医学 | 1322篇 |
口腔科学 | 96篇 |
临床医学 | 960篇 |
内科学 | 2525篇 |
皮肤病学 | 92篇 |
神经病学 | 477篇 |
特种医学 | 308篇 |
外科学 | 1633篇 |
综合类 | 297篇 |
一般理论 | 2篇 |
预防医学 | 649篇 |
眼科学 | 123篇 |
药学 | 788篇 |
中国医学 | 92篇 |
肿瘤学 | 736篇 |
出版年
2023年 | 63篇 |
2022年 | 75篇 |
2021年 | 203篇 |
2020年 | 137篇 |
2019年 | 199篇 |
2018年 | 262篇 |
2017年 | 184篇 |
2016年 | 197篇 |
2015年 | 249篇 |
2014年 | 318篇 |
2013年 | 391篇 |
2012年 | 560篇 |
2011年 | 605篇 |
2010年 | 356篇 |
2009年 | 346篇 |
2008年 | 478篇 |
2007年 | 625篇 |
2006年 | 535篇 |
2005年 | 515篇 |
2004年 | 482篇 |
2003年 | 396篇 |
2002年 | 373篇 |
2001年 | 378篇 |
2000年 | 338篇 |
1999年 | 310篇 |
1998年 | 139篇 |
1997年 | 170篇 |
1996年 | 137篇 |
1995年 | 110篇 |
1994年 | 99篇 |
1993年 | 55篇 |
1992年 | 174篇 |
1991年 | 151篇 |
1990年 | 144篇 |
1989年 | 129篇 |
1988年 | 134篇 |
1987年 | 116篇 |
1986年 | 93篇 |
1985年 | 67篇 |
1984年 | 51篇 |
1983年 | 61篇 |
1982年 | 38篇 |
1981年 | 29篇 |
1980年 | 26篇 |
1979年 | 65篇 |
1978年 | 32篇 |
1977年 | 33篇 |
1976年 | 32篇 |
1974年 | 27篇 |
1973年 | 31篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.
23.
Eleven (3%) of 340 patients with hepatocellular carcinoma (HCC) presented with obstructive jaundice. The tumor extensively infiltrated the major bile ducts in eight patients. Jaundice was relieved by endoscopic endoprosthesis in four patients, nasobiliary drainage in two patients, percutaneous transhepatic stenting in one patient, and surgical intubation in one patient. The survival interval of these eight patients (mean +/- SD) was 35 +/- 20 days. Three patients had tumor fragments in the common bile ducts. In two patients, major hepatic resection was done after initial tube decomposition of the biliary system. One patient remained tumor-free on follow-up at 24 months, and the other patient had recurrent tumor detected on follow-up at 17 months after surgery. The tumor was irresectable in the third patient. Multiple surgical and endoscopic procedures kept the bile duct patent for 17 months before the patient died of the disease. Not all patients who present with obstructive jaundice due to HCC are terminally ill. With proper management, good palliation and occasional cure are possible. 相似文献
24.
1. It is now recognized that atrial fibrillation (AF) is not a benign condition, as it is associated with a 40% increase in mortality and a doubling of the risk of stroke. 2. The development of AF leads to mechanical, electrophysiological and cellular changes in the atria that tend to sustain AF. This process is known as atrial remodelling. 3. The three electrophysiological elements in the atria that initiate and sustain AF are: (i) shortening of the refractory period and an increase in dispersion; (ii) slowing of conduction velocity; and (iii) the presence of triggerin. foci. 4. As AF is a heterogeneous disorder, therapeutic strategies include the use of devices (pacemakers and atrial defibrillators), radiofrequency ablation (focal ablation or the creation of linear lines) and drug therapy that may reverse a remodelle. atrium. 相似文献
25.
T. K. Lau MRCOG F. Chan MBChB 《The Australian & New Zealand journal of obstetrics & gynaecology》1994,34(2):216-217
EDITORIAL COMMENT: We accepted these case reports for publication not only to remind readers that a classical Caesarean scar is more likely than a lower uterine segment scar to rupture or dehisce, but also to stress that women should be counselled appropriately when classical Caesarean section has been performed. Our Australian population is also mobile and women may not return to the same institution or obstetrician for their next confinement. Tracing the details of a previous delivery from another hospital or practitioner even in the same community should be a routine enquiry when a patient has had a Caesarean section in a previous pregnancy but the required information is often difficult to obtain. The woman herse(fis the essential repository for this information. It should also be noted that the recent increase in the number of Caesarean sections performed for fetal indications before 30 weeks' gestation has resulted in more vertical incisions because of a poorly formed lower uterine segment. 相似文献
26.
27.
Background : A retrospective analysis of 103 case records from 1978 to 1996 with a provisional diagnosis of Buerger's disease was undertaken at the Department of Surgery, University of Hong Kong, Queen Mary Hospital. The aim of the study was to elucidate the clinical course and evaluate the results of surgical intervention of Buerger's disease in Hong Kong Chinese people. Methods : Fourteen patients were subsequently excluded from the study because of inability to fulfil our diagnostic criteria. Data on clinical presentation, investigations, indications and results of surgical intervention were reviewed. Sympathectomies and arterial reconstructions were performed on 42 and four patients, respectively, for critical ischaemia or rest pain. Outcome was analysed with respect to the rate of ulcer healing, pattern of recurrence and limb loss. Results : The patients were all young male heavy smokers with a mean age of 36.5 years. The majority of patients (80%) presented with ischaemic ulceration or gangrene. Vascular reconstruction was undertaken in four patients and satisfactory long-term results were obtained in three patients. Sympathectomy was able to relieve symptoms in 87% of operated patients and ischaemic ulceration healed in 2.6 (mean) ± 1.7 (SD) months after the operation. If the patient continued to smoke, surgical intervention did not exempt the patient from a relapse or amputation. Conclusion : Sympathectomy provides short-term pain relief and promotes ulcer healing in patients with Buerger's disease but carries no long-term benefit. Complete abstinence from smoking is the only means of arresting the progression of the disease. 相似文献
28.
Interventional cardiologists today are overwhelmed by a hugh array of new high technology investigatory devices at their disposal for the treatment of coronary arterial obstructive disease. These include the various atherectomy and laser devices, developed and introduced into clinical practice with the promise and intent of solving the limitations of conventional balloon angioplasty, namely those of acute closure and restenosis. But as more experience and data are obtained from the application of these devices, it is becoming clear that the latter have generally not been able to accomplish what they were intended to do. Although the immediate success rates have been uniformly high, acute closure has persisted and restenosis remains unabated. Nevertheless, some of these new devices have shown some fairly encouraging results in specific clinical circumstances. The targeted use of these instruments may prove to be a step in the right direction. This article reviews the current state of the art and the potential utility of certain of these devices. 相似文献
29.
30.
W M Lau 《Pharmacology》1992,45(1):9-16
The K+ channel openers cromakalim and pinacidil induced a concentration-dependent reduction in atrial contraction force with EC50 values of 25 +/- 2 and 37 +/- 2 mumol/l, respectively. This depressant effect was antagonised by 50 mumol/l tacrine which displaced the concentration-response curves of cromakalim and pinacidil to the right. The respective DR50 values were 3.8 and 2.3. Increasing the tacrine concentration (100 and 500 mumol/l) produced no additional effect on the concentration-response relationships. Addition of 1 mumol/l atropine enhanced the antagonism due to tacrine by increasing the DR50 value from 3.8 to 6.5 for cromakalim and from 2.3 to 5.2 for pinacidil. Glibenclamide, an ATP-sensitive K+ channel blocker, competitively inhibited the negative inotropic effects of cromakalim and pinacidil. The respective dissociation constants for glibenclamide against cromakalim and pinacidil were 0.57 and 0.35 mumol/l. Neither apamin nor variation in external Ca2+ concentration affected the negative inotropic effects of the K+ channel openers. It was suggested that the mechanical effects of cromakalim and pinacidil are mediated through the ATP-sensitive K+ channels in the heart. 相似文献