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   7621篇
  免费   592篇
  国内免费   18篇
耳鼻咽喉   16篇
儿科学   226篇
妇产科学   138篇
基础医学   859篇
口腔科学   131篇
临床医学   929篇
内科学   1592篇
皮肤病学   78篇
神经病学   594篇
特种医学   423篇
外科学   1343篇
综合类   297篇
一般理论   6篇
预防医学   732篇
眼科学   66篇
药学   399篇
中国医学   6篇
肿瘤学   396篇
  2022年   56篇
  2021年   105篇
  2020年   75篇
  2019年   112篇
  2018年   140篇
  2017年   95篇
  2016年   120篇
  2015年   121篇
  2014年   138篇
  2013年   284篇
  2012年   350篇
  2011年   387篇
  2010年   230篇
  2009年   187篇
  2008年   307篇
  2007年   344篇
  2006年   373篇
  2005年   284篇
  2004年   331篇
  2003年   286篇
  2002年   285篇
  2001年   266篇
  2000年   258篇
  1999年   241篇
  1998年   134篇
  1997年   113篇
  1996年   119篇
  1995年   69篇
  1994年   81篇
  1993年   86篇
  1992年   181篇
  1991年   194篇
  1990年   167篇
  1989年   168篇
  1988年   138篇
  1987年   137篇
  1986年   122篇
  1985年   143篇
  1984年   103篇
  1983年   87篇
  1982年   56篇
  1981年   49篇
  1980年   47篇
  1979年   69篇
  1978年   62篇
  1977年   45篇
  1976年   41篇
  1974年   44篇
  1973年   42篇
  1969年   35篇
排序方式: 共有8231条查询结果,搜索用时 15 毫秒
81.
82.
83.
84.
Lifestyle interventions, including meal replacement, are effective in the prevention and treatment of type-2-diabetes and obesity. Since insulin is the key weight regulator, we hypothesised that the addition of meal replacement to a lifestyle intervention reduces insulin levels more effectively than lifestyle intervention alone. In the international multicentre randomised controlled ACOORH (Almased Concept against Overweight and Obesity and Related Health Risk) trial, overweight or obese persons who meet the criteria for metabolic syndrome (n = 463) were randomised into two groups. Both groups received nutritional advice focusing on carbohydrate restriction and the use of telemonitoring devices. The intervention group substituted all three main meals per day in week 1, two meals per day in weeks 2–4, and one meal per day in weeks 5–26 with a protein-rich, low-glycaemic meal replacement. Data were collected at baseline and after 1, 3, 6 and 12 months. All datasets providing insulin data (n = 446) were included in this predefined subanalysis. Significantly higher reductions in insulin (−3.3 ± 8.7 µU/mL vs. −1.6 ± 9.8 µU/mL), weight (−6.1 ± 5.2 kg vs. −3.2 ± 4.6 kg), and inflammation markers were observed in the intervention group. Insulin reduction correlated with weight reduction and the highest amount of weight loss (−7.6 ± 4.9 kg) was observed in those participants with an insulin decrease > 2 µU/mL. These results underline the potential for meal replacement-based lifestyle interventions in diabetes prevention, and measurement of insulin levels may serve as an indicator for adherence to carbohydrate restriction.  相似文献   
85.
PurposeThe purpose of this study was for an international panel of experts to establish consensus indications for distal rectus femoris surgery in children with cerebral palsy (CP) using a modified Delphi method.MethodsThe panel used a five-level Likert scale to record agreement or disagreement with 33 statements regarding distal rectus femoris surgery. The panel responded to statements regarding general characteristics, clinical indications, computerized gait data, intraoperative techniques and outcome measures. Consensus was defined as at least 80% of responses being in the highest or lowest two of the five Likert ratings, and general agreement as 60% to 79% falling into the highest or lowest two ratings. There was no agreement if neither threshold was reached.ResultsConsensus or general agreement was reached for 17 of 33 statements (52%). There was general consensus that distal rectus femoris surgery is better for stiff knee gait than is proximal rectus femoris release. There was no consensus about whether the results of distal rectus femoris release were comparable to those following distal rectus femoris transfer. Gross Motor Function Classification System (GMFCS) level was an important factor for the panel, with the best outcomes expected in children functioning at GMFCS levels I and II. The panel also reached consensus that they do distal rectus femoris surgery less frequently than earlier in their careers, in large part reflecting the narrowing of indications for this surgery over the last decade.ConclusionThis study can help paediatric orthopaedic surgeons optimize decision-making for, and outcomes of, distal rectus femoris surgery in children with CP.Level of evidenceV  相似文献   
86.
Population‐based indicators of the coverage of key elements of high‐quality family planning services are tracked via household surveys with female respondents, yet little work has been done to establish their validity. We take advantage of existing data sets from Cambodia and Kenya to compare women's responses at exit interviews following a health facility visit against the observations of a trained third‐party observer during the visit. The results, which treat the observations as the reference standard, show that indicators that measure contraceptive methods received are accurately reported while indicators of whether the woman received her preferred method and whether information was “discussed” or “explained” during counseling are less reliably reported. Studies designed explicitly to assess the validity of family planning questions in household surveys, especially questions in large survey programs critical for monitoring demographic trends and programmatic coverage, are needed.  相似文献   
87.
Summary The results of the European Working Party for Hypertension in the Elderly Study showed that treatment of high blood pressure reduced the morbidity and mortality from strokes and myocardial infarction and reduced the incidence of heart failure in elderly patients. The largest number of hypertensive patients are elderly, and it is in this group of patients that the maximum benefit of treatment might be expected. The present study was designed to study in detail the efficacy and tolerability of ketanserin in an elderly population. Seventeen elderly (> 70 years) patients with a lying systolic blood pressure of 160 mmHg and/or a diastolic blood pressure of 90 mmHg were included in the study. For the 12 patients who completed the study, the mean blood pressure was significantly reduced on ketanserin compared with placebo (p<0.001) in the supine and erect positions. The mean net changes in blood pressure after 8 weeks were 21/17 mmHg and 23/16 mmHg erect. Heart rate was also significantly reduced (p<0.001) by a mean of 8 beats/min lying and 9 beats/min erect. Analysis of ambulatory 24-hour ECG tapes showed no significant effect of ketanserin on heart rhythms. Ketanserin therapy had no significant effect on routine hematology, plasma electrolytes, biochemistry, or urinalysis. Total exchangeable sodium and potassium and body weight were also unchanged. On ketanserin treatment, the overall quality of life score was significantly improved (p=0.002; analysis of variance on log transformed data) compared with the placebo phase.  相似文献   
88.
This research analyzes the effect which recent speed limit increases on rural interstate highways have had upon accidents that are alcohol-related. Although there has been considerable work on the separate highway safety effects of higher speed limits and alcohol-related accidents, surprisingly little work has explicitly examined the relationship between them. Based upon extensive county wide data on alcohol-related accidents and several theoretically important determinants of these accidents for the state of Indiana and over the period 1981 through 1989, fixed effects models were estimated. For the state as a whole, the analysis finds that the increase in rural interstate speed limits increased alcohol-related accidents and the magnitude of the effect was statistically significant. In addition, the relaxed speed limit led to a significant redistribution of alcohol-related accidents away from higher speed environments and towards lower speed environments. With few exceptions, this was true for every type of alcohol-related highway accident examined.  相似文献   
89.
Acute porphyria is rare in orientals. We describe a Chinese woman with recurrent generalised tonic-clonic seizures and abdominal pain. Genomic DNA studies identified a heterozygous base substitution from guanine to adenine at nucleotide position 503, resulting in substitution of arginine by histidine at position 168 of the protein (R168H). This genetic abnormality is similar to the mutation reported in Caucasians with variegate porphyria. To the best of our knowledge, this is the first report in the English literature a Chinese patient with variegate porphyria with an identifiable mutation. A brief review of porphyria is presented.  相似文献   
90.
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