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   3770篇
  免费   270篇
  国内免费   15篇
耳鼻咽喉   13篇
儿科学   105篇
妇产科学   38篇
基础医学   599篇
口腔科学   43篇
临床医学   385篇
内科学   996篇
皮肤病学   44篇
神经病学   289篇
特种医学   121篇
外国民族医学   1篇
外科学   554篇
综合类   14篇
一般理论   3篇
预防医学   259篇
眼科学   54篇
药学   216篇
中国医学   13篇
肿瘤学   308篇
  2023年   23篇
  2022年   14篇
  2021年   114篇
  2020年   64篇
  2019年   101篇
  2018年   103篇
  2017年   80篇
  2016年   69篇
  2015年   93篇
  2014年   129篇
  2013年   152篇
  2012年   247篇
  2011年   292篇
  2010年   123篇
  2009年   130篇
  2008年   228篇
  2007年   212篇
  2006年   191篇
  2005年   207篇
  2004年   178篇
  2003年   172篇
  2002年   190篇
  2001年   64篇
  2000年   39篇
  1999年   49篇
  1998年   45篇
  1997年   51篇
  1996年   33篇
  1995年   28篇
  1994年   22篇
  1993年   22篇
  1992年   48篇
  1991年   42篇
  1990年   53篇
  1989年   63篇
  1988年   46篇
  1987年   33篇
  1986年   38篇
  1985年   28篇
  1984年   25篇
  1983年   16篇
  1982年   19篇
  1981年   13篇
  1977年   15篇
  1976年   13篇
  1975年   11篇
  1970年   10篇
  1969年   10篇
  1968年   10篇
  1965年   11篇
排序方式: 共有4055条查询结果,搜索用时 328 毫秒
1.

Background

The Lancet Commission on Global Surgery highlighted global surgical need but offered little insight into the specific surgical challenges of children in low-resource settings. Efforts to strengthen the quality of global pediatric surgical care have resulted in a proliferation of partnerships between low-and middle-income countries (LMICs) and high-income countries (HICs). Standardized tools able to reliably measure gaps in delivery and quality of care are important aids for these partnerships. We undertook a systematic review (SR) of capacity assessment tools (CATs) focused on needs assessment in pediatric surgery.

Methods

A comprehensive search strategy of multiple electronic databases was conducted per PRISMA guidelines without linguistic or temporal restrictions. CATs were selected according to pre-defined inclusion criteria. Articles were assessed by two independent reviewers. Methodological quality of studies was appraised using the COSMIN checklist with 4-point scale.

Results

The search strategy generated 16,641 original publications, of which three CATs were deemed eligible. Eligible tools were either excessively detailed or oversimplified. None used weighted scores to identify finer granularity between institutions. No CATs comprehensively included measures of resources, outcomes, accessibility/impact and training.

Discussion

The results of this study identify the need for a CAT capable of objectively measuring key aspects of surgical capacity and performance in a weighted tool designed for pediatric surgical centers in LMICs.

Type of Study

Systematic Review.

Level of Evidence

II.  相似文献   
2.
Efficacy and safety of mycophenolate mofetil (MMF) may be optimized with individualized doses based on therapeutic monitoring of its active metabolite, mycophenolic acid (MPA). In this 12-month study, 137 renal allograft recipients from 11 French centers receiving basiliximab, cyclosporine A, MMF and corticosteroids were randomized to receive either concentration-controlled doses or fixed-dose MMF. A novel Bayesian estimator of MPA AUC based on three-point sampling was used to individualize doses on posttransplant days 7 and 14 and months 1, 3 and 6. The primary endpoint was treatment failure (death, graft loss, acute rejection and MMF discontinuation). Data from 65 patients/group were analyzed. At month 12, the concentration-controlled group had fewer treatment failures (p = 0.03) and acute rejection episodes (p = 0.01) with no differences in adverse event frequency. The MMF dose was higher in the concentration-controlled group at day 14 (p < 0.0001), month 1 (p < 0.0001) and month 3 (p < 0.01), as were median AUCs on day 14 (33.7 vs. 27.1 mg*h/L; p = 0.0001) and at month 1 (45.0 vs. 30.9 mg*h/L; p < 0.0001). Therapeutic MPA monitoring using a limited sampling strategy can reduce the risk of treatment failure and acute rejection in renal allograft recipients 12 months posttransplant with no increase in adverse events.  相似文献   
3.
4.
Strains of Saccharomyces cerevisiae FL200 capable of growing on a solid medium containing a mixture of polyene macrolide antibiotics (nystatin, 40 micrograms/ml, amphotericin B, 40 micrograms/ml, pimaricin, 150 micrograms/ml and RP9971 antibiotic, 10 micrograms/ml) have been isolated after successive selection steps. The mutant strains, PR13 and PRC24, are 10 to 100 times more resistant than the polyene macrolide antibiotics. When 4% Tween 80 is added to the medium, resistance to these antifungal drugs is further increased. In addition, strain PRC24, derived from strain PR13, is resistant to a non-polyene macrolide antifungal antibiotic, cycloheximide. In contrast, PR13 and PRC24 are both highly susceptible to a large range of compounds, including non-polyenic antifungal, antitumor and antibacterial agents. These particular characteristics make these strains useful for the rapid detection of antifungal compounds of the polyene macrolide and cycloheximide types, as well as for the recognition of antimitotic substances.  相似文献   
5.
Pediatric liver transplant recipients constitute a population characterized by a particularly unpredictable and poor bioavailability of cyclosporin (CyA). Even though several adult studies show that the new oral formulation of CyA, Neoral (NEO), produces better bioavailability and blood level predictability, few data describe its pharmacokinetics in children. We performed a complete analysis of the pharmacokinetics of NEO in ten small children after primary liver transplantation. Three pharmacokinetic profiles were set up with data obtained from tests taken during i. v. administration of CyA, after the first oral NEO dose, and after the last NEO dose before discharge from the hospital. The mean half-lives obtained were 8.1, 7.7, and 6.9 h, respectively, and the bioavailabilities were 22 % and 21 % for the first and last NEO doses. A large interpatient variability was observed. This was due, in part, to episodes of diarrhea that interfered with the pharmacokinetic evaluation and, in part, to the variability of post-transplant hepatic function. There was a good correlation between CyA trough levels and their related AUCs for both NEO profiles (r = 0.93 and r = 0.74, respectively). We conclude that, even though the pediatric OLT population remains more unpredictable than that of adults, NEO has a relatively rapid half-life and a remarkably improved bioavailability. Received: 29 November 1996 Received after revision: 10 April 1997 Accepted: 15 May 1997  相似文献   
6.
The potential gravity of post-operative vascular infection makes early diagnosis essential. We report a case where this diagnosis was made on CT findings alone, in the absence of any other signs of infection. Rapid intervention led to complete cure. Beyond the immediate post-operative period, the presence of gas on the CT scan is rare but pathognomonic in the absence of a cutaneous fistula. The presence of this sign is therefore sufficient to indicate that reintervention is mandatory.  相似文献   
7.

Background  

Hypophosphatasia (HP) is characterized by a genetic defect in the tissue-nonspecific alkaline phosphatase (TNSALP) gene and predominantly an autosomal recessive trait. HP patients suffer from reduced bone mineralization. Biochemically, elevated concentrations of substrates of TNSALP, including pyridoxal-5'-phosphate and inorganic pyrophosphate occur in serum, tissues and urine. The latter has been associated with chronic inflammation and hyperprostaglandinism.  相似文献   
8.
Several common postdischarge symptoms, such as sleep disorders, headache, drowsiness or general malaise, evoke disturbances of circadian rhythms due to jet lag (ie crossing time zones) or shift work rotation. Considering that general anesthesia is associated with numerous effects on the central nervous system, we hypothesized that it may also act on the circadian timing system. We first determined the effects of the circadian timing on general anesthesia. We observed that identical doses of propofol showed marked circadian fluctuations in duration of effects, with a peak at the middle of the resting period (ie 7 h after lights on). Then, we examined the effects of general anesthesia on circadian timing, by analysing stable free-running circadian rhythms (ie in constant environmental conditions), an experimental approach used widely in circadian biology. Free-running rats were housed in constant darkness and temperature to assess possible phase-shifting effects of propofol anesthesia according to the time of the day. When administered around (+/-2 h) the daily rest/activity transition point, a 30-min propofol anesthesia induced a 1-h phase advance in the free-running rest-activity rhythm, while anesthesia had no significant resetting effect at other times of the day. Anesthesia-induced hypothermia was not correlated with the phase-shifting effects of propofol anesthesia. From our results, anesthesia itself can reset circadian timing, and acts as a synchronizing cue for the circadian clock.  相似文献   
9.
Exfoliative toxin D (ETD) was identified recently as a new exfoliative toxin serotype. Like other exfoliative toxins, ETD induces intra-epidermal cleavage through the granular layer of the epidermis of neonatal mice. The distribution of ETD production was investigated in Staphylococcus aureus isolates from infected and colonised patients in France. The etd gene was found in 55 (10.5%) of 522 isolates tested. Isolates responsible for bullous impetigo and generalised staphylococcal scalded skin syndrome did not harbour etd, but etd was significantly more frequent in isolates causing cutaneous abscesses and furuncles. Most etd- and Panton-Valentine leukocidin-positive strains belonged to the clone of community-acquired methicillin-resistant S. aureus spreading currently throughout France.  相似文献   
10.
Background: Open exploration and endoscopic sphincterotomy (ES) remain the preferred treatment of common bile duct stones (CBDS). The recent spread of laparoscopy has worsened the dilemna of choosing between surgical and endoscopic treatment of CBDS. The aim of this study was to critically evaluate the results of our preliminary experience with laparoscopic common bile duct exploration (CBDE) for CBDS. Methods: Ninety-two consecutive patients were prospectively submitted to laparoscopic CBDE. Surgical strategy included an initial transcystic approach or laparoscopic choledochotomy. Failure of stone clearance was managed by conversion to open CBDE or by postoperative ES. Electrohydraulic lithotripsy and papillary balloon dilatation were selectively used. Stone clearance was assessed by choledochoscopy and control cholangiography. Results: The overall laparoscopic stone clearance in this series was 84% (transcystic route 63% and choledochotomy 93%). Conversion to laparotomy was mandatory in 12% of the patients because of incomplete stone clearance and in 5% because of intraoperative complications. Postoperative ES was required in 4% of the patients, giving an overall surgical success rate of 96%. When indicated (small and limited number of stones located below the cysticocholedochal junction, with a dilated and patent cystic duct) the transcystic route had the lower success rate, the higher complication rate, and the shorter operative time and postoperative hospital stay. When indicated (accessible and dilated common bile duct over 7 mm), laparoscopic choledochotomy had the higher success rate, the lower complication rate, the longer operative time, and the longer postoperative hospital stay, which is related to associated external biliary drainage. The hospital mortality included two high-risk patients (2%) and the complications rate was 15%. Conclusions: Laparoscopic CBDE is safe in selected patients. A stratified intraoperative surgical strategy is mandatory in deciding between a transcystic route and choledochotomy with specific indications for each approach. When feasible, laparoscopic choledochotomy is more efficient and safe than the transcystic route, but it is associated with a longer postoperative hospital stay, which is due to external biliary drainage. Received: 7 May 1996/Accepted: 19 November 1996  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