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   847篇
  免费   44篇
  国内免费   45篇
耳鼻咽喉   6篇
儿科学   20篇
妇产科学   10篇
基础医学   75篇
口腔科学   10篇
临床医学   88篇
内科学   177篇
皮肤病学   4篇
神经病学   67篇
特种医学   77篇
外科学   172篇
综合类   19篇
一般理论   1篇
预防医学   34篇
眼科学   17篇
药学   111篇
中国医学   9篇
肿瘤学   39篇
  2023年   11篇
  2022年   15篇
  2021年   20篇
  2020年   17篇
  2019年   18篇
  2018年   26篇
  2017年   27篇
  2016年   16篇
  2015年   32篇
  2014年   33篇
  2013年   49篇
  2012年   73篇
  2011年   71篇
  2010年   50篇
  2009年   24篇
  2008年   36篇
  2007年   52篇
  2006年   45篇
  2005年   43篇
  2004年   43篇
  2003年   61篇
  2002年   40篇
  2001年   11篇
  2000年   18篇
  1999年   15篇
  1998年   9篇
  1997年   6篇
  1995年   6篇
  1994年   3篇
  1993年   8篇
  1992年   4篇
  1991年   4篇
  1990年   7篇
  1989年   6篇
  1988年   2篇
  1987年   2篇
  1985年   3篇
  1984年   1篇
  1983年   4篇
  1982年   4篇
  1981年   2篇
  1980年   6篇
  1979年   1篇
  1977年   1篇
  1976年   1篇
  1974年   3篇
  1972年   1篇
  1971年   1篇
  1966年   2篇
  1965年   1篇
排序方式: 共有936条查询结果,搜索用时 15 毫秒
11.

Background:

Goal‐directed fluid therapy (GDFT) has been compared with liberal fluid administration in non‐optimized perioperative settings. It is not known whether GDFT is of value within an enhanced recovery protocol incorporating fluid restriction. This study evaluated GDFT under these circumstances in patients undergoing elective colectomy.

Methods:

Patients undergoing elective laparoscopic or open colectomy within an established enhanced recovery protocol (including fluid restriction) were randomized to GDFT or no GDFT. Bowel preparation was permitted for left colonic operations at the surgeon's discretion. Exclusion criteria included rectal tumours and stoma formation. The primary outcome was a patient‐reported surgical recovery score (SRS). Secondary endpoints included clinical outcomes and physiological measures of recovery.

Results:

Eighty‐five patients were randomized, and there were 37 patients in each group for analysis. Nine patients in the GDFT and four in the fluid restriction group received oral bowel preparation for either anterior resection (12) or subtotal colectomy (1). Patients in the GDFT group received more colloid during surgery (mean 591 versus 297 ml; P = 0·012) and had superior cardiac indices (mean corrected flow time 374 versus 355 ms; P = 0·018). However, no differences were observed between the GDFT and fluid restriction groups with regard to surgical recovery (mean SRS after 7 days 47 versus 46 respectively; P = 0·853), other secondary outcomes (mean aldosterone/renin ratio 9 versus 8; P = 0·898), total postoperative fluid (median 3750 versus 2400 ml; P = 0·604), length of hospital stay (median 6 versus 5 days; P = 0·570) or number of patients with complications (26 versus 27; P = 1·000).

Conclusion:

GDFT did not provide clinical benefit in patients undergoing elective colectomy within a protocol incorporating fluid restriction. Registration number: NCT00911391 ( http://www.clinicaltrials.gov ). Copyright © 2012 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.  相似文献   
12.
13.
14.

Objective

An awake craniotomy facilitates radical excision of eloquent area gliomas and ensures neural integrity during the excision. The study describes our experience with 67 consecutive awake craniotomies for the excision of such tumours.

Methods

Sixty-seven patients with gliomas in or adjacent to eloquent areas were included in this study. The patient was awake during the procedure and intraoperative cortical and white matter stimulation was performed to safely maximize the extent of surgical resection.

Results

Of the 883 patients who underwent craniotomies for supratentorial intraaxial tumours during the study period, 84 were chosen for an awake craniotomy. Sixty-seven with a histological diagnosis of glioma were included in this study. There were 55 men and 12 women with a median age of 34.6 years. Forty-two (62.6%) patients had positive localization on cortical stimulation. In 6 (8.9%) patients white matter stimulation was positive, five of whom had responses at the end of a radical excision. In 3 patients who developed a neurological deficit during tumour removal, white matter stimulation was negative and cessation of the surgery did not result in neurological improvement. Sixteen patients (24.6%) had intraoperative neurological deficits at the time of wound closure, 9 (13.4%) of whom had persistent mild neurological deficits at discharge, while the remaining 7 improved to normal. At a mean follow-up of 40.8 months, only 4 (5.9%) of these 9 patients had persistent neurological deficits.

Conclusion

Awake craniotomy for excision of eloquent area gliomas enable accurate mapping of motor and language areas as well as continuous neurological monitoring during tumour removal. Furthermore, positive responses on white matter stimulation indicate close proximity of eloquent cortex and projection fibres. This should alert the surgeon to the possibility of postoperative deficits to change the surgical strategy. Thus the surgeon can resect tumour safely, with the knowledge that he has not damaged neurological function up to that point in time thus maximizing the tumour resection and minimizing neurological deficits.  相似文献   
15.

Introduction and hypothesis

Accurate diagnosis of a wide spectrum of urethral/periurethral pathologies in women remains challenging due to its anatomical location and nonspecific clinical presentations. Magnetic resonance imaging (MRI) has emerged as the modality of choice for diagnosing female urethral and periurethral pathologies due to its multiplanar scanning capability, superior soft tissue differentiation, noninvasive nature, and overall excellent contrast resolution.

Methods

In this narrative review, we describe the use of MRI to visualize the female urethra and periurethral pathologies.

Results

MRI can confidently characterize lesions into cystic or solid, provide a more succinct differential diagnosis, and in some cases provide a specific and accurate diagnosis, enabling surgeons to prepare a roadmap before operative procedure. Moreover, functional MRI can be useful to assess dynamic disorders such as urethral hypermobility.

Conclusions

We provide a comprehensive review of normal MR anatomy of the female urethra, as well as the MR features of practically important urethral and periurethral lesions.
  相似文献   
16.
17.
Srinivasa MR  Phelan C 《Allergy》2007,62(8):965-966
  相似文献   
18.
Neurons in posterior parietal cortex (PPC) may serve both proprioceptive and exteroceptive functions during prehension, signaling hand actions and object properties. To assess these roles, we used digital video recordings to analyze responses of 83 hand-manipulation neurons in area 5 as monkeys grasped and lifted objects that differed in shape (round and rectangular), size (large and small spheres), and location (identical rectangular blocks placed lateral and medial to the shoulder). The task contained seven stages -- approach, contact, grasp, lift, hold, lower, relax -- plus a pretrial interval. The four test objects evoked similar spike trains and mean rate profiles that rose significantly above baseline from approach through lift, with peak activity at contact. Although representation by the spike train of specific hand actions was stronger than distinctions between grasped objects, 34% of these neurons showed statistically significant effects of object properties or hand postures on firing rates. Somatosensory input from the hand played an important role as firing rates diverged most prominently on contact as grasp was secured. The small sphere -- grasped with the most flexed hand posture -- evoked the highest firing rates in 43% of the population. Twenty-one percent distinguished spheres that differed in size and weight, and 14% discriminated spheres from rectangular blocks. Location in the workspace modulated response amplitude as objects placed across the midline evoked higher firing rates than positions lateral to the shoulder. We conclude that area 5 neurons, like those in area AIP, integrate object features, hand actions, and grasp postures during prehension.  相似文献   
19.
Tuberculosis (TB) is a highly dreaded, infectious, chronic, airborne disease affecting more than two million people all around the world, with more than eight million cases every calendar year. TB is the second leading infectious cause of death after HIV/AIDS. Over the past few decades, numerous efforts have been undertaken to develop new anti‐TB agents. The current frontline therapy for TB consists of administering three or more different drugs (usually isoniazid, rifampin, pyrazinamide, and ethambutol) over an extended period of time. But these drugs will take 6–12 months to cure TB, along with many side effects; hence, there is an urgent need to explore new anti‐TB agents. Quinoxaline derivatives are a class of compounds that show a spectrum of biological properties and the interest in these compounds is exponentially growing within the field of medicinal chemistry. Quinoxaline‐1,4‐di‐N‐oxide derivatives have shown to improve the biological results and are endowed with anti‐viral, anti‐cancer, anti‐bacterial, and anti‐protozoal activities with application in many other therapeutic areas. Since quinoxaline derivatives are regarded as a new class of effective anti‐TB candidates, their 1,4‐di‐N‐oxide analogues may show promising in vitro and in vivo anti‐TB activities and might be able to prevent the drug resistance to a certain extent. Therefore, the main aim of this review is to focus on important quinoxaline and quinoxaline‐1,4‐di‐N‐oxide analogues that have shown anti‐TB activities, and their structure–activity relationships for designing anti‐TB agents with better efficacies. The present review will be helpful in providing insights for rational designs of more active and less toxic quinoxaline‐based anti‐TB prodrugs.
  相似文献   
20.
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