全文获取类型
收费全文 | 27237篇 |
免费 | 1860篇 |
国内免费 | 247篇 |
专业分类
耳鼻咽喉 | 429篇 |
儿科学 | 421篇 |
妇产科学 | 602篇 |
基础医学 | 3964篇 |
口腔科学 | 703篇 |
临床医学 | 2337篇 |
内科学 | 5283篇 |
皮肤病学 | 584篇 |
神经病学 | 2028篇 |
特种医学 | 1607篇 |
外科学 | 4380篇 |
综合类 | 286篇 |
一般理论 | 11篇 |
预防医学 | 1118篇 |
眼科学 | 664篇 |
药学 | 2355篇 |
1篇 | |
中国医学 | 272篇 |
肿瘤学 | 2299篇 |
出版年
2023年 | 164篇 |
2022年 | 388篇 |
2021年 | 725篇 |
2020年 | 392篇 |
2019年 | 668篇 |
2018年 | 723篇 |
2017年 | 595篇 |
2016年 | 693篇 |
2015年 | 1032篇 |
2014年 | 1277篇 |
2013年 | 1451篇 |
2012年 | 2166篇 |
2011年 | 2135篇 |
2010年 | 1312篇 |
2009年 | 1196篇 |
2008年 | 1641篇 |
2007年 | 1570篇 |
2006年 | 1469篇 |
2005年 | 1394篇 |
2004年 | 1258篇 |
2003年 | 1090篇 |
2002年 | 959篇 |
2001年 | 774篇 |
2000年 | 759篇 |
1999年 | 600篇 |
1998年 | 210篇 |
1997年 | 202篇 |
1996年 | 176篇 |
1995年 | 147篇 |
1994年 | 126篇 |
1993年 | 102篇 |
1992年 | 242篇 |
1991年 | 185篇 |
1990年 | 176篇 |
1989年 | 168篇 |
1988年 | 143篇 |
1987年 | 104篇 |
1986年 | 96篇 |
1985年 | 69篇 |
1984年 | 78篇 |
1983年 | 49篇 |
1982年 | 52篇 |
1981年 | 44篇 |
1980年 | 43篇 |
1979年 | 56篇 |
1978年 | 44篇 |
1977年 | 46篇 |
1974年 | 37篇 |
1972年 | 44篇 |
1971年 | 42篇 |
排序方式: 共有10000条查询结果,搜索用时 25 毫秒
121.
A H Sabbagh G K Chung J J Fernandez D Gann R A Cohn P D Citron 《International surgery》1987,72(2):96-99
Two hundred fifty eight patients had percutaneous transluminal coronary angioplasty. Of those, 48 cases underwent surgical revascularization for unsuccessful angioplasty. Sex was not a risk factor. Timely surgical revascularization reversed acute ischemia and/or myocardial infarction or limited the size of the infarction in 32 of the 48 patients or 67%. Revascularization procedures were performed in six out of forty-eight patients who had previous aortocoronary by-pass surgery and attempted PTCA, none had any complications. Death occurred in one out of forty-eight patients, or 2%. Femoral-femoral by-pass devices, in addition to intra-aortic balloon devices, should be available in the cardiac catheterization laboratory. Patients with multi-vessel disease are at greater risk of angioplasty and surgery. Sixteen out of 23 patients (70%) who had emergency revascularization procedures had multi-vessel disease. In one patient with borderline renal function, emergency surgery after PTCA with a large amount of renograffin dye injected caused renal failure and led to permanent dialysis. 相似文献
122.
R S Chung 《Annals of surgery》1987,206(3):335-339
Sutureline blood flow was measured with laser Doppler velocimetry in colonic anastomoses created with the stapler, manual suturing, or a combination. Blood flow was always reduced in the sutureline compared with normal mucosa. Of all the anastomoses studied, tight stapling reduced sutureline blood flow the most, whereas the two-layered manual anastomosis or stapling reinforced with sutures were somewhat less ischemic. Stapling adjusted to bowel wall thickness impaired flow only moderately. It was possible with practice to outperform the stapler by single-layered manual anastomosis using fine sutures. In humans, stapled ileocolostomy had a higher sutureline blood flow than the two-layered manual anastomosis. In view of the existing clinical experience of safe stapling without adjustment for bowel wall thickness, a low sutureline blood flow is probably tolerated to a considerable degree in humans. However, this study clearly shows that tight stapling can reduce sutureline blood flow unduly, whereas superior blood supply can be attained by attention to staple closure height relative to bowel wall thickness. 相似文献
123.
124.
The glomerular filtration rate (GFR), renal plasma flow (RPF) and renal blood flow (RBF) were all markedly decreased in rats given an adenine diet as the period of adenine administration lengthened. Concurrently, the urinary excretions of prostaglandin E2 (PGE2) and 6-keto-prostaglandin F1 alpha(6-keto-PGF1 alpha) decreased gradually in parallel with the renal function parameters, whereas the urinary excretion of thromboxane B2 (TXB2) increased markedly. These findings suggest the involvement of prostaglandin in the renal circulation. 相似文献
125.
Jae Sue Choi Han Suk Young Jong Cheol Park Jin-Ho Choi Won Sick Woo 《Archives of pharmacal research》1986,9(4):233-236
The flavonoids isolated from the leaves ofRhododendron brachycarpum, were identified as quercetin, avicularin, quercitrin and hyperin. 相似文献
126.
127.
Dissection and transection of the cystic duct close to the gallbladder has been advocated as a means of avoiding common bile injury during laparoscopic cholecystectomy (LC). We present three cases in which inadequate identification of the gallbladder—cystic duct junction resulted in incomplete cholecystectomy. In two patients an unsecured gallbladder infundibulum presented as cystic duct leaks and one patient developed recurrent symptomatic cholelithiasis. These cases emphasize the need for complete dissection and visualization of the cystic duct at the gallbladder prior its division and secure ligation during LC. 相似文献
128.
Travis L. Boaz Jonathan S. Lewin Yiu-Cho Chung Jeffrey L. Duerk Mark E. Clampitt John R. Haaga 《Journal of magnetic resonance imaging : JMRI》1998,8(1):64-69
The purpose of this study was to determine the suitability of MRI to accurately detect radiofrequency (RF) thermoablative lesions created under MR guidance. In vivo RF lesions were created in the livers of six New Zealand White rabbits using a 2-mm-diameter titanium alloy RF electrode with a 20-mm exposed tip and a 50-W RF generator. This was performed using a 0.2T clinical C-arm MR imager for guidance and monitoring. Each animal was sacrificed and gross evaluation was performed. Histologic correlation was performed on the first two animals. The MR-compatible RF electrode was easily identified on rapid gradient-echo images used to guide electrode placement. A single lesion was created in each rabbit liver. Lesions ranged from approximately 10 to 17 mm in diameter (mean, 13.5 mm). T2-weighted and short T1 inversion recovery (STIR) images demonstrated lesions ranging in diameter from 12 to 18 mm (mean, 14.6 mm). Lesion dimensions determined from images closely correlated with those determined at gross examination with the discrepancy never exceeding 2 mm, for an r2 value of .87. MRI performed at the time of MR-guided RF ablation accurately demonstrated created lesions. This modality may provide a new option for the treatment of local and regional neoplastic disease. 相似文献
129.
D. G. Kim C.-Y. Kim S. H. Paek D. S. Lee J.-K. Chung H.-W. Jung B.-K. Cho 《Acta neurochirurgica》1998,140(7):665-674
Summary
Background To determine its roles in the diagnosis and the systemic evaluation of metastatic brain tumours, whole-body positron emission
tomography (PET) using [18F]FDG was performed in 20 consecutive patients.
Methods
All patients were thought to be suffering or needing to be differentiated from metastatic brain tumours. Nine patients had
multiple brain lesions; six were older and showed a rim-enhancing lesion with surrounding oedema; seven had homogeneously
enhancing periventricular lesion(s) on computed tomography (CT) and/or magnetic resonance (MR) imaging, thought to be central
nervous system lymphomas. Two patients had skull mass(es) and two patients had a solid mass suspected to be, respectively,
a haemorrhagic metastasis and a metastatic malignant melanoma. All of them received whole-body [18F]FDG PET and conventional systemic work-up for metastasis in order to compare the results of the two methods.
Results
Metastatic brain tumours were diagnosed on whole-body [18F]FDG PET in eleven patients who had extracranial and intracranial hypermetabolic lesions. In nine of these, a conventional
work-up also detected primary lesions which on whole-body [18F]FDG PET were seen to be hypermetabolic foci. Systemic lymph node metastases were detected by whole-body [18F]FDG PET only in two patients and histological diagnosis was possible by biopsy of lymph nodes rather than of brain lesions.
In the remaining nine patients who had only intracranial hypermetabolic foci, histological diagnosis was made by craniotomy
or stereotactic biopsy. It was confirmed that seven of nine patients were suffering from a primary brain tumour and two from
metastatic carcinoma. None of the nine showed evidence of systemic cancer on conventional work-up. Histological diagnoses
of the primary brain tumours were four cases of primary central nervous system lymphoma and one each of multifocal glioblastoma,
Ewing's sarcoma, and cavernous angioma.
Patients felt no discomfort during the whole-body [18F]FDG PET procedure and there were no complications. The false negative rate in [18F]FDG PET and in conventional work-up was 15.4% and 30.7% respectively. There were no false positives on either [18F]FDG PET or conventional work-up.
Conclusion
It is suggested that whole-body [18F]FDG PET is a safe, reliable, and convenient method for the diagnosis and systemic evaluation of patients thought to be suffering
or needing to be differentiated from a metastatic brain tumour. 相似文献
130.
Ngai Suk Wai; Tang Oi Shan; Lao Terence; Ho Pak Chung; Ma Ho Kei 《Human reproduction (Oxford, England)》1995,10(5):1220-1222
Intravaginal misoprostol has been shown to be effective forcervical priming before a surgically induced abortion. The objectivewas to investigate the effectiveness of oral misoprostol incervical dilatation prior to vacuum aspiration between the 6thand 12th weeks of pregnancy. The results showed that in nulliparouspatients, the median cervical dilatation in the treatment group(7.8 mm) was significantly greater than that in the placebogroup (3.7 mm). In multiparous patients, the difference wasalso statistically significant (9.8 versus 6.0 mm). The easeof dilatation, assessed subjectively by the operating surgeons,was significantly improved in the treatment group. There wasalso a significant reduction in the duration of the operationand in the mean blood loss in the treatment group. The side-effectsencountered in the treatment group were mild and well acceptedby the women. Oral misoprostol is an effective and safe methodfor cervical dilatation prior to vacuum aspiration in firsttrimester pregnancy. 相似文献