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   39285篇
  免费   1908篇
  国内免费   181篇
耳鼻咽喉   309篇
儿科学   718篇
妇产科学   627篇
基础医学   5010篇
口腔科学   1006篇
临床医学   2636篇
内科学   9669篇
皮肤病学   620篇
神经病学   2810篇
特种医学   1370篇
外科学   7310篇
综合类   177篇
预防医学   1301篇
眼科学   456篇
药学   2905篇
中国医学   131篇
肿瘤学   4319篇
  2023年   207篇
  2022年   419篇
  2021年   710篇
  2020年   408篇
  2019年   569篇
  2018年   701篇
  2017年   541篇
  2016年   625篇
  2015年   705篇
  2014年   913篇
  2013年   1055篇
  2012年   1693篇
  2011年   1778篇
  2010年   999篇
  2009年   814篇
  2008年   1560篇
  2007年   1667篇
  2006年   1655篇
  2005年   1708篇
  2004年   1742篇
  2003年   1656篇
  2002年   1670篇
  2001年   1671篇
  2000年   1611篇
  1999年   1539篇
  1998年   535篇
  1997年   439篇
  1996年   387篇
  1995年   340篇
  1994年   332篇
  1993年   292篇
  1992年   989篇
  1991年   930篇
  1990年   809篇
  1989年   900篇
  1988年   771篇
  1987年   698篇
  1986年   742篇
  1985年   677篇
  1984年   431篇
  1983年   374篇
  1982年   191篇
  1981年   185篇
  1979年   309篇
  1978年   239篇
  1977年   208篇
  1975年   209篇
  1974年   185篇
  1973年   173篇
  1971年   176篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
141.
142.
143.
The effect of ganglioside on diabetic neurogenic bladder   总被引:1,自引:0,他引:1  
The effect of ganglioside was studied in 6 diabetic patients with neurogenic bladder. Ganglioside is glycosphingolipids which seems to be involved in the processes of nerve growth, regeneration and tissue reinnervation. The treatment consisted in the daily intramuscular administration of 20 mg ganglioside. Clinical symptoms, vibration sensation and urodynamic studies were recorded at the beginning and 4 weeks later. The clinical responses assessed by subjective complaints and vibration sensation were effective, but no statistically significant difference in urodynamic studies was obtained. Side effects were not observed. In conclusion, ganglioside treatment seems to have a positive effect on diabetic neurogenic bladder.  相似文献   
144.
A 54 year-old man was admitted to our hospital with a compliant of high fever following the dental treatment. He had the straight thoracic spine with absence of physiological kyphosis. Blood culture was positive for Streptococcus sanguis I. Echocardiography revealed the mitral valve regurgitation with some vegetation at the ruptured chordae tendinae of the posterior leaflet. The operation was performed after the sign of the inflammation was disappeared. We performed the mitral valve reconstruction following the Carpentier's technique. The half of the posterior leaflet was excised, and the annuloplasty and valvuloplasty was done with ease.  相似文献   
145.
146.
Objective: The purpose of this experimental study was to investigate whether aortic stent grafting can be applied to the treatment of an esophageal cancer involving the thoracic aorta. Methods: The canine thoracic aorta was partially resected without aorta being clamped after emplacement of an endovascular stent graft. Study I; The aortic whole layer of 1 cm in length and 1/4 of the circumference was resected and was covered by a free fascia patch of the abdominal rectal muscle immediately after stent graft placement. Study II; The aortic adventitia and the outer half of the media of the same size was resected on day 3, 7,14, 21, and on day 28, after the stent graft placement. The resected portion was covered by the free fascia patch in half experimental dogs, and was uncovered in the others. Study III; The aortic adventitia and the outer half of the media of 1 cm in length and 1/2 of the circumference was resected and was uncovered on day 7 after stent graft placement. Histological examinations were performed on day 28 and at one year after aortic resection. Results: The aortic wall could be resected in all cases with no complication, except in resection of 1/2 the circumference where the aorta had become narrow. There was no difference in healing of the resected portion of the aorta between with and without fascia covering. Conclusion: An aortic endovascular stent graft could be applied to surgery for an esophageal cancer involving the aorta.  相似文献   
147.
While attrition from sharp bony surfaces is the most common cause of extensor digiti minimi (EDM) tendon rupture, the etiology of other cases of spontaneous EDM tendon rupture is still unknown. Friction within the compartment may play a role, especially with ulna dislocation. The purpose of this study was to compare gliding resistance of the EDM tendon with that of a tendon which rarely ruptures spontaneously, the extensor digitorum communis of the middle finger (EDC III) tendon, under various wrist and ulna head positions. Eight fresh frozen cadavers were used. Gliding resistance between the tendon and its sheath in each compartment was measured in five different wrist positions and three different ulna head positions. Gliding resistance of the EDM tendon (0.13 +/- 0.03 N) was significantly greater than the EDC III tendon (0.09 +/- 0.03 N) (p < 0.05). For the EDM tendon, the gliding resistance in ulnar deviation or pronation was higher than the gliding resistance in neutral, radial deviation, or supination (p < 0.05), and the gliding resistance with ulnar lengthening (over 6 mm) or dorsal ulnar dislocation (over 9 mm) was higher than in neutral ulnar head positioning. For the EDC III tendon, the gliding resistance in ulnar deviation was significantly higher than the gliding resistance in neutral, radial deviation, or supination, or dorsal dislocation with ulnar lengthening (p < 0.05). Wrist ulnar deviation, ulnar dorsal dislocation (over 9 mm), and ulnar lengthening (over 6 mm) increased the gliding resistance of the EDM tendon. In patients at risk for EDM rupture, such as those with rheumatoid arthritis or distal radioulnar joint osteoarthritis, avoiding such positions may be advantageous.  相似文献   
148.
149.
It has been known that clarithromycin (TE-031, A-56268), a new macrolide antibiotic (ML), achieves higher concentrations in blood, is better excreted into urine and is better distributed into various tissues than conventional MLs. We investigated the pharmacokinetics of TE-031 in children upon oral administration of the drug in the following method. TE-031 granular preparation with a potency of 100 mg/g was given to 6 boys (5 years 4 months-14 years 0 month) with dose levels of 5 mg/kg and 10 mg/kg for each 3 boys. A tablet preparation with each tablet containing 50 mg of TE-031 was administered to 4 boys and 2 girls (8 years 5 months-11 years 6 months) with dose level of 2 tablets (i.e., 100 mg) and 3 tablets (i.e., 150 mg) for each 3 children. All administrations were done at 30 minutes before meal. Then, to conduct a cross-over test, the granule preparation was given orally to the 3 children mentioned above who was given 2 tablets and the 1 of 3 cases that were given 3 tablets at the same dose levels (100 mg and 150 mg) respectively. A bioassay was used to determine concentrations in blood of active antibiotic compounds and an high performance liquid chromatography (HPLC) was used to determine unchanged TE-031 and its main metabolite, M-5. Urinary concentrations of active antibiotic compounds were also determined by the bioassay and the HPLC was used to determine concentrations and proportions of unchanged TE-031 and its metabolites, M-1, M-4, M-5, M-6 and M-7 to figure out the urinary recovery rate in the first 6 hours. The results of these experiments are summarized as follows. 1. As was mentioned above, TE-031 was administered orally to 2 groups of children at dose levels of 5 mg/kg and 10 mg/kg, respectively. Mean serum levels of total active antibiotic compounds reached their maximum in 1 and 2 hours for the 5 mg/kg and the 10 mg/kg dosage groups, respectively, at 1.28 and 3.62 micrograms/ml, respectively. Mean half lives of serum concentrations in the 2 groups were quite similar, with values of at 2.1 and 2.0 hours, respectively. Mean serum concentrations of unchanged TE-031 determined by the HPLC method reached their peaks in 1 hour after administration in either of the 5 and 10 mg/kg dosage groups at peak levels of 0.65 micrograms/ml and 2.67 micrograms/ml, respectively. Thus, dose-response relationships were observed with TE-031 and M-5.(ABSTRACT TRUNCATED AT 400 WORDS)  相似文献   
150.
A case of a cervical cancer in a 40-year-old woman with a plasma carcinoembryonic antigen (CEA) level of 29.4 ng/ml was investigated using light and electron microscopy. In addition, the plasma CEA levels before treatment were determined in 168 patients with cervical cancer and in 33 patients with endometrial cancer. CEA was found to be elevated in the plasma of 19% of those with cervical cancer and in 6% of those with endometrial cancer. Effective serial plasma CEA determinations following therapy, in patients whose plasma or tumors initially contain elevated amounts of antigen, might be useful as an adjunctive method in the earlier detection of a recurrent cancer.  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