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   3163篇
  免费   126篇
  国内免费   28篇
耳鼻咽喉   6篇
儿科学   74篇
妇产科学   26篇
基础医学   496篇
口腔科学   11篇
临床医学   188篇
内科学   709篇
皮肤病学   12篇
神经病学   407篇
特种医学   223篇
外科学   452篇
综合类   8篇
预防医学   66篇
眼科学   78篇
药学   187篇
中国医学   4篇
肿瘤学   370篇
  2022年   20篇
  2021年   32篇
  2020年   26篇
  2019年   50篇
  2018年   53篇
  2017年   35篇
  2016年   56篇
  2015年   63篇
  2014年   68篇
  2013年   103篇
  2012年   163篇
  2011年   146篇
  2010年   64篇
  2009年   72篇
  2008年   117篇
  2007年   132篇
  2006年   160篇
  2005年   148篇
  2004年   148篇
  2003年   147篇
  2002年   145篇
  2001年   66篇
  2000年   71篇
  1999年   54篇
  1998年   34篇
  1997年   60篇
  1996年   55篇
  1995年   36篇
  1994年   44篇
  1993年   23篇
  1992年   52篇
  1991年   68篇
  1990年   44篇
  1989年   97篇
  1988年   83篇
  1987年   103篇
  1986年   93篇
  1985年   78篇
  1984年   44篇
  1983年   30篇
  1982年   22篇
  1981年   20篇
  1980年   16篇
  1979年   33篇
  1978年   32篇
  1977年   22篇
  1973年   15篇
  1972年   9篇
  1969年   11篇
  1967年   7篇
排序方式: 共有3317条查询结果,搜索用时 15 毫秒
81.
82.
83.
The principle of empirical therapy for patients with intra-abdominal infections (IAI) should include antibiotics with activity against Enterobacteriaceae and Bacteroides fragilis group species. Coverage of Pseudomonas aeruginosa, Enterobacter cloacae, and Enterococcus faecalis is also recommended for hospital-associated IAI. A nationwide survey was conducted to investigate the antimicrobial susceptibility of pathogens isolated from postoperative IAI. All 504 isolates were collected at 26 institutions and referred to a central laboratory for susceptibility testing. Lower susceptibility rates to ciprofloxacin and cefepime were demonstrated in Escherichia coli. Among E. coli, 24.1% of strains produced extended-spectrum β-lactamase (ESBL). Carbapenems, piperacillin/tazobactam, cephamycins/oxacephem, aminoglycosides, and tigecycline had high activity against E. coli, including ESBL-producing isolates. Among E. cloacae, low susceptibility rates to ceftazidime were demonstrated, whereas cefepime retained its activity. P. aeruginosa revealed high susceptibility rates to all antimicrobials tested except for imipenem. Among B. fragilis group species, low levels of susceptibility were observed for cefoxitin, moxifloxacin, and clindamycin, and high susceptibility rates were observed for piperacillin/tazobactam, meropenem, and metronidazole. Ampicillin, piperacillin, and glycopeptides had good activity against E. faecalis. Imipenem had the highest activity against E. faecalis among carbapenems. In conclusion, we suggested the empirical use of antimicrobials with the specific intent of covering the main organisms isolated from postoperative IAI. Piperacillin/tazobactam, meropenem, or doripenem, are appropriate in critically ill patients. Combination therapy of cefepime (aztreonam in patients with β-lactam allergy) plus metronidazole plus glycopeptides, imipenem/cilastatin or cephamycins/oxacephem plus ciprofloxacin plus metronidazole are potential therapeutic options.  相似文献   
84.

Introduction

This was the first exploratory randomized controlled study to compare the efficacy and safety of a preserved tafluprost/timolol fixed combination (TAF/TIM) with a preserved latanoprost/timolol fixed combination (LAT/TIM).

Methods

This prospective, randomized, open-label study was conducted in Japanese patients with primary open-angle glaucoma, including normal-tension glaucoma or ocular hypertension. Following a 4-week LAT/TIM run-in period, eligible patients entered a 12-week treatment period, during which they received either LAT/TIM or TAF/TIM. The efficacy endpoint was the change in intraocular pressure (IOP) from baseline to week 12 and the safety endpoints included the changes from baseline to week 12 in superficial punctate keratopathy (SPK) score, tear breakup time (TBUT), and hyperemia score, as well as adverse events (AEs). At week 6, ocular symptoms were evaluated using a questionnaire.

Results

In total, 131 patients provided informed consent. Of these, 115 completed the run-in period and were assigned to receive TAF/TIM (n?=?60) or LAT/TIM (n?=?55). At week 12, there were no significant differences between the TAF/TIM and LAT/TIM groups in the change from baseline in trough IOP and IOP at 4–6 h after instillation. There were no significant differences between the two groups in the change from baseline to week 12 in SPK score, TBUT, and hyperemia score. However, only in the TAF/TIM group, the total SPK score and the inferior cornea SPK score were significantly lower at week 12 compared with baseline. Eye irritation and eye pain were significantly decreased in the TAF/TIM group compared with the LAT/TIM group. Two treatment-related AEs were reported in the TAF/TIM group (3.3%) and none in the LAT/TIM group, while no serious AEs were reported in either group.

Conclusion

TAF/TIM is as effective as LAT/TIM in terms of IOP-reducing effect, with fewer ocular symptoms. TAF/TIM was associated with a significant improvement in SPK scores.

Trial Registration

UMIN Clinical Trials Registry Identifier, UMIN000023862.

Funding

Santen Pharmaceutical Co., Ltd., Osaka, Japan.
  相似文献   
85.
Journal of Gastroenterology - This multicenter prospective study (UMIN000019958) aimed to evaluate the usefulness of serum leucin-rich alpha-2 glycoprotein (LRG) levels in monitoring disease...  相似文献   
86.
Journal of Gastroenterology - Liquid biopsies, particularly those involving circulating tumor DNA (ctDNA), are rapidly emerging as a non-invasive alternative to tumor biopsies. However, clinical...  相似文献   
87.
88.
We present a case of esophageal carcinoma in which esophagectomy was not possible because of tuberculous fibrosing mediastinitis. A 77-year-old man was diagnosed with carcinoma of the thoracic esophagus and admitted to our hospital. Chest radiography on admission revealed no abnormality except pleural thickening of the pulmonary apices, suggesting a history of subclinical infection of tuberculous pleurisy. The patient underwent surgery with a curative intent. Thoracotomy revealed that the mediastinum had been replaced with dense fibrous tissues and was widely encased with laminar calcification. Esophagectomy was not performed because it was considered impossible to do so safely. Although diagnosis of fibrous mediastinitis was not made preoperatively, review of the preoperative computed tomographic scans revealed proliferation of mediastinal soft tissues that were associated with patchy and laminar calcifications. Tuberculous fibrosing mediastinitis is an uncommon but clinically important disease for physicians who are involved in the diagnosis and treatment of esophageal cancer.  相似文献   
89.
We report the presence of a patent ductusvenosus in three brothers who underwent surgicalcorrection. Patent ductus venosus was demonstrated byultrasonography. Portosystemic venous shunt ratios asevaluated by [123I]iodoamphetamine per rectalportal scintigraphy were 67%, 50%, and 77%,respectively. Histologic examination of liver biopsyspecimens revealed fatty degeneration in all cases.Portal vein pressure before and after temporarily occluding thepatent ductus venosus was estimated by an Anthron P-Ucatheter introduced into the portal vein via theligament teres hepatis. Portal venous pressure increased from 10 to 17 cm H2O, 16 to 23 cmH2O, and 14 to 27 cm H2O,respectively. Therefore, banding of the ductus venosuswith Teflon tape was attempted to prevent portalhypertension following complete ligation. As a result, portal venous pressures afterstricture of the ductus venosus were 12, 21, and 20 cmH2), respectively. Bile acid and liver enzymes decreasedand returned to normal within 14 days after surgery. Interestingly, serum concentrations ofhepatocyte growth factor (HGF) increased significantlyafter restoration of the portal blood flow and thengradually decreased, but remained persistently elevated for at least two weeks in two cases measuredafter surgical correction. One month after correction,liver function returned to normal as assessed byserological and histological parameters in all cases. These results suggest that it is important todetermine whether stricture or complete ligation isindicated for a patent ductus venosus during surgicalcorrection, based on the portal venous pressure after temporal test occlusion of the duct. Inaddition, HGF may be a useful marker for normalizationof hepatic microcirculation after surgery.  相似文献   
90.
BACKGROUND: Atrioventricular (AV) delay optimization may be important in patients with biventricular pacing and the optimal AV delay can be predicted using Doppler echocardiography and the formula: optimal AV delay = AV delay-the interval between the end of A wave and complete closure of the mitral valve when the AV delay is set at slightly prolonged AV delay. METHODS AND RESULTS: In the present study the efficacy of this method was evaluated in 5 patients (67.4+/-8.0 (SD) years old) with biventricular pacing. Cardiac output (CO) and diastolic filling time were measured by Doppler echocardiography. When the AV delay was set at the predicted optimal AV delay -25 ms, the predicted optimal AV delay (133+/-66 ms) and predicted optimal AV delay + 25 ms, the respective CO were 4.5+/-0.9, 5.3+/-1.0, 4.8+/-1.0 L/min (p<0.05, ANOVA) and the diastolic filling times were 364 +/-100, 373+/-105, 335+/-84 ms (p<0.05, ANOVA). Congestive heart failure improved from New York Heart Association class 3.6+/-0.5 to 1.4+/-0.5 (p<0.001). CONCLUSIONS: AV delay optimization is important in patients with biventricular pacing and can be easily achieved by the new method.  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