全文获取类型
收费全文 | 36402篇 |
免费 | 1688篇 |
国内免费 | 203篇 |
专业分类
耳鼻咽喉 | 367篇 |
儿科学 | 842篇 |
妇产科学 | 458篇 |
基础医学 | 4590篇 |
口腔科学 | 903篇 |
临床医学 | 2288篇 |
内科学 | 9632篇 |
皮肤病学 | 589篇 |
神经病学 | 2698篇 |
特种医学 | 1207篇 |
外科学 | 6717篇 |
综合类 | 153篇 |
一般理论 | 3篇 |
预防医学 | 1015篇 |
眼科学 | 566篇 |
药学 | 2500篇 |
中国医学 | 143篇 |
肿瘤学 | 3622篇 |
出版年
2023年 | 197篇 |
2022年 | 342篇 |
2021年 | 610篇 |
2020年 | 310篇 |
2019年 | 454篇 |
2018年 | 571篇 |
2017年 | 530篇 |
2016年 | 564篇 |
2015年 | 574篇 |
2014年 | 774篇 |
2013年 | 967篇 |
2012年 | 1561篇 |
2011年 | 1667篇 |
2010年 | 1053篇 |
2009年 | 890篇 |
2008年 | 1634篇 |
2007年 | 1774篇 |
2006年 | 1782篇 |
2005年 | 1901篇 |
2004年 | 1777篇 |
2003年 | 1804篇 |
2002年 | 1801篇 |
2001年 | 1244篇 |
2000年 | 1315篇 |
1999年 | 1163篇 |
1998年 | 533篇 |
1997年 | 387篇 |
1996年 | 385篇 |
1995年 | 346篇 |
1994年 | 314篇 |
1993年 | 341篇 |
1992年 | 816篇 |
1991年 | 756篇 |
1990年 | 697篇 |
1989年 | 756篇 |
1988年 | 672篇 |
1987年 | 643篇 |
1986年 | 564篇 |
1985年 | 538篇 |
1984年 | 352篇 |
1983年 | 299篇 |
1979年 | 270篇 |
1978年 | 189篇 |
1977年 | 169篇 |
1974年 | 160篇 |
1973年 | 172篇 |
1972年 | 166篇 |
1971年 | 158篇 |
1970年 | 159篇 |
1969年 | 146篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
961.
962.
Matsushita K Ishikawa T Sumita S Yamakawa Y Kobayashi T Kawasaki N Matsumoto K Taima M Uchino K Kimura K Umemura S 《Journal of cardiology》2004,44(2):65-71
A 79-year-old man presented with dilated cardiomyopathy and chronic atrial fibrillation. A DDD pacemaker was implanted due to sick sinus syndrome. His left ventricular ejection fraction was 23%. He was repeatedly admitted with congestive heart failure. Although cardiac resynchronization therapy was attempted, insertion of a pacing lead into the coronary sinus failed. Right ventricular bifocal pacing was done. The QRS width was shortened to 155 msec during bifocal pacing and 157 msec during right ventricular outflow pacing from 221 msec during right ventricular apical pacing. Heart failure was improved from New York Heart Association class III to II. Regional wall motion was assessed by strain of the myocardium. Bifocal pacing increased stroke volume due to improvement of longitudinal dyssynchrony of the septal and lateral walls. Bifocal pacing is effective for patients with severe congestive heart failure in whom biventricular pacing therapy has failed. Strain Doppler imaging is useful for the assessment of regional wall motion during cardiac pacing. 相似文献
963.
964.
Uemura M Sasaki Y Yamada T Eguchi H Ohigashi H Doki Y Murata K Miyashiro I Ishikawa O Takami H Kobayashi T Imaoka S 《Hepato-gastroenterology》2004,51(59):1259-1262
Hepatocellular carcinomas, of which the tumor thrombus extends into the right atrium via the inferior vena cava, may soon cause fatal complications. Only surgery can be an effective treatment. This procedure usually needs the aid of cardiopulmonary bypass. We recently experienced a successful surgery to remove thrombus combined with hepatectomy. Reporting the detailed technique, both associated diagnosis and intraoperative management are discussed herein. We were able to perform hepatectomy of tumor thrombus in the right atrium without the use of cardiopulmonary bypass or veno-venous bypass. The tumor thrombus was removed from the right atrium into the suprahepatic inferior vena cava by reducing the liver on the tail side. And after total hepatic vascular exclusion was achieved, the intracaval tumor thrombus and the right lobe of the liver were removed en bloc. The operation took 545 minutes and the total hepatic vascular exclusion period was 32 minutes. The postoperative course was uneventful. There are some key points for this procedure. Preoperative or intraoperative US is essential in judging whether tumor thrombus can be removed from the right atrium into the inferior vena cava by reducing the liver or not. Test clamping of the inferior vena cava prior to total hepatic vascular exclusion will enable us to judge whether veno-venous bypass during total hepatic vascular exclusion is needed or not. Surgery without the use of cardiopulmonary bypass is safe and can be minimally invasive when it is performed with a reliable diagnosis and technique. 相似文献
965.
Minatoguchi S Takemura G Chen XH Wang N Uno Y Koda M Arai M Misao Y Lu C Suzuki K Goto K Komada A Takahashi T Kosai K Fujiwara T Fujiwara H 《Circulation》2004,109(21):2572-2580
966.
Katsuhiko Iwakiri Hidenori Kanazawa Satoshi Matsuzaka Norihiko Tada Hitoshi Saitoh Hitoshi Yoshimoto Yoshiya Nakagawa Yuuji Osada Toshiaki Sugiura Makoto Kotoyori Yasutaka Mamiya Hisagi Yamada Yoshiyuki Narahara Akihiko Kawakami Masafumi Kobayashi 《Journal of gastroenterology》1998,33(3):305-309
The effects of transjugular intrahepatic portosystemic shunt (TIPS) placement on esophageal motor function and gastroesophageal
reflux were investigated in patients with esophageal varices. In six men with esophageal varices, esophageal manometry and
upper gastrointestinal endoscopy were performed before and 15–20 days after TIPS placement. Intraesophageal pH monitoring
was performed in the four patients with severe esophageal varices (defined as the largest sized varices) following TIPS placement.
Findings were compared with those in six healthy men (controls) who underwent esophageal manometry and intraesophageal pH
monitoring. The esophageal varices resolved or were reduced after TIPS placement. Resting lower esophageal sphincter (LES)
pressures were similar in the study group before and after TIPS placement and in the control subjects. The incidence and progression
of esophageal contractions were similar in the study group before and after TIPS placement and in the control subjects. At
3 cm above the LES, the amplitude of esophageal contraction after TIPS placement was significantly higher than that before
TIPS placement. At 3 and 8 cm above the LES, the amplitude of esophageal contraction in the control subjects was significantly
higher than that in the study group before and after TIPS placement. Esophageal acid exposure time after TIPS placement was
similar to that in the controls. TIPS placement is a useful treatment that improves esophageal motor function without the
occurrence of pathologic gastroesophageal reflux.
(Received May 28, 1997; accepted Sept. 26, 1997) 相似文献
967.
Sugisaki K Saito R Takagi T Shio K Shioya Y Fukaya E Iwadate H Sekine H Orikasa H Kobayashi H Watanabe H Sato Y 《Modern rheumatology / the Japan Rheumatism Association》2005,15(1):56-61
We report a case of HLA-B52-positive Behçet disease accompanied by multiarterial lesions. A 24-year-old woman was suffering from sporadic high fever and recurrent oral and genital ulcers, and laboratory data revealed severe inflammation. A diagnosis of Behçet disease was made. Magnetic resonance angiography, ultrasound study, and computed tomographic angiography demonstrated multiarterial lesions that had caused no symptoms. These noninvasive examinations were extremely useful in evaluating asymptomatic early vascular lesions. 相似文献
968.
Radiofrequency ablation of pulmonary tumors and normal lung tissue in swine and rabbits 总被引:5,自引:0,他引:5
OBJECTIVE: The purpose of the present study was to examine the following during radiofrequency ablation (RFA): (1) the risk of hemorrhage from intrapulmonary large vessels; (2) the risk of incomplete ablation of pulmonary tumors; and (3) the late effect on lung tissue. MATERIALS AND METHODS: A 17-gauge, cool-tip-type radiofrequency electrode was used. The damage to the vessels and bronchi was examined by the injection of a colored silicone rubber, a liquid compound that hardens after injection. To examine the risk of hemorrhage from intrapulmonary large vessels, RFA was conducted at eight sites near the central pulmonary vessels in two swine. To examine the risk of an incomplete ablation for pulmonary tumors, 10 pulmonary nodules were made from a gelatin mixture in another two swine and were treated by RFA. To examine the late effect on lung tissue, RFA was conducted on the peripheral lung in 10 rabbits, and then the ablated regions were examined on days 1, 7, 14, 21, and 28 after RFA. RESULTS: The use of colored silicone rubber enabled us to examine the intrapulmonary vessels and bronchi for opening and leakage. RFA did not damage the large intrapulmonary vessels, even when they were located within the ablated regions. Lung tissue surrounding the gelatin nodules was hardly ablated over its entire circumference. Six of 10 gelatin nodules (60%) showed nonablated areas on the peripheral edges of the nodules. From 21 days after RFA, the ablated rabbit lung formed noninfectious cavities by communicating with the surrounding bronchi. CONCLUSION: It was improbable for hemorrhage to occur even when RFA was conducted near the large intrapulmonary large vessels. Because an incomplete ablation that left tumor cells at the site of ablation could occur during surgery due to the difficulty of ablating the entire tumor circumference, CT scan-guided RFA would be preferable to a surgical approach for making a safe margin. Cavity formation can occur beginning 21 days after RFA, which should be carefully followed up in a clinical setting to identify infection, especially in immunocompromised patients. 相似文献
969.
Effects of vitamin K(2) (menatetrenone) and alendronate on bone mineral content and bone mechanical property in rats fed a low-magnesium diet. Recent clinical studies have shown that the occurrence of new fractures does not always depend on bone mineral density. Therefore bone quality has become an important issue in osteoporosis research. No animal model for evaluating bone quality has been established. In this study, we found that the treatment of rats with a low-magnesium (Mg) diet reduced their bone strength without decreasing bone mineral content (BMC), so the low Mg diet model is considered to be a good model for examining bone quality. Using this model, we investigated the effects of vitamin K(2) (V.K(2)) and alendronate (ALN). V.K(2) increased maximum load and elastic modulus without influencing BMC. ALN increased maximum load with increasing BMC. By using Fourier transform infrared microscopic analysis, the low-Mg diet treatment increased the mineral/matrix ratio of bones, and V.K(2) suppressed the increase in this ratio. These findings suggest that the mineral/matrix ratio may be a factor involved in bone quality, and that V.K(2) may improve bone quality. 相似文献
970.
Makoto Saegusa Yasuo Takano Hiroshi Kishimoto Go Wakabayashi Katsuhiko Nohga Masahiko Okudaira 《Journal of cancer research and clinical oncology》1993,119(12):737-744
Expression of p53 and c-myc was investigated and compared with cell proliferative activity in a series of 40 hepatocellular carcinomas (HCC), by means of enhanced immunohistochemistry. p53 expression was demonstrated in 5 out of 40 HCC (12.5%) with the incidence increasing in proportion to the histological grading of malignancy: thus, 0% of well-differentiated, 6.9% of moderately differentiated and 33.3% of poorly differentiated lesions were positive. The proliferating-cell nuclear antigen (PCNA) labeling index also showed a statistically significant increase with this grading. Distribution patterns of PCNA-positive cell were divided into four types: scatter, marginal, mosaic and diffuse. Four HCC cases, predominantly of the poorly differentiated type, exhibited the diffuse pattern. Generally, p53 overexpression corresponded well with PCNA positivity. In contrast, there was no correlation between c-myc overexpression, found in 19 out of 40 HCC (47.5%), and histological grading of HCC or PCNA labeling index. The distribution pattern of c-myc-positive HCC cells was also different from that of PCNA and p53. Our results suggest that p53 overexpression closely relates to proliferation of HCC cells. Furthermore, there may be a consistent difference in regulatory mechanisms between p53 and c-myc expression in multistep hepatocarcinogenesis. 相似文献