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   467篇
  免费   13篇
  国内免费   1篇
耳鼻咽喉   6篇
儿科学   12篇
妇产科学   54篇
基础医学   28篇
口腔科学   11篇
临床医学   62篇
内科学   107篇
皮肤病学   18篇
神经病学   28篇
外科学   25篇
综合类   1篇
一般理论   1篇
预防医学   84篇
眼科学   6篇
药学   32篇
肿瘤学   6篇
  2021年   2篇
  2017年   3篇
  2016年   5篇
  2015年   9篇
  2014年   10篇
  2013年   21篇
  2012年   3篇
  2011年   2篇
  2010年   25篇
  2009年   11篇
  2008年   7篇
  2007年   2篇
  2001年   5篇
  2000年   5篇
  1999年   10篇
  1998年   17篇
  1997年   25篇
  1996年   27篇
  1995年   19篇
  1994年   15篇
  1993年   16篇
  1992年   19篇
  1991年   15篇
  1990年   13篇
  1989年   11篇
  1988年   22篇
  1987年   13篇
  1986年   8篇
  1985年   17篇
  1984年   9篇
  1983年   15篇
  1982年   16篇
  1981年   10篇
  1980年   6篇
  1979年   7篇
  1978年   7篇
  1977年   8篇
  1976年   2篇
  1975年   5篇
  1973年   2篇
  1972年   3篇
  1971年   4篇
  1969年   5篇
  1968年   3篇
  1963年   2篇
  1959年   2篇
  1958年   3篇
  1955年   1篇
  1946年   1篇
  1930年   1篇
排序方式: 共有481条查询结果,搜索用时 93 毫秒
11.
Mant A, Eyland E A, Pond D C, Saunders N A and Chancellor AH B. Recognition of dementia in general practice: comparisonof general practitioners' opinions with assessments using themini-mental state examination and the Blessed dementia ratingscale. Family Practice 1988; 5: 184–188. In a study of 226 elderly residents in a retirement villagein Sydney, Australia, general practitioners' opinions aboutdementia status had high positive and negative predictive valuesand high specificity, but low sensitivity when evaluated againstthe mini-mental state examination and the Blessed dementia ratingscale. General practitioners were found to disagree with thesetwo measures more often when patients were in advanced old age,and when they considered the patients to be depressed. We concludethat the general practitioner can increase his or her sensitivityto dementia in the elderly by use of either measure.  相似文献   
12.
13.
This study was undertaken to investigate a number of immuneparameters which may be compromised with exposure to morphinesulfate. Mice were implanted subcutaneously with 8-, 25-, or75-mg morphine sulfate pellets. Placebo pellets of identicalmakeup to the 75-mg morphine pellet (without morphine of course)were used as a control. Twenty-four hours after implantationof a 75-mg morphine pellet, blood levels reached a peak of 1610ng/ml. Corticosterone increased in parallel with morphine andreached a peak level of 966 ng/ml 24 hr after implantation.The dose response of morphine to increase corticosterone, however,was fiat. The weight of the lymphoid organs, spleen and thymus,and the liver were significantly reduced in the morphine-treatedgroups. Morphine treatment was associated with an increase inserum albumin, SGPT, BUN, and alkaline phosphatase indicativeof hepatic damage. In contrast to increased serum proteins,the C3 component of complement was reduced in a dose-dependentmanner. Leukocyte number in the peripheral blood was significantlyreduced, while erythro-cyte number and hematocrit were bothincreased. The number of B cells and T cells was decreased inmorphine-treated animals. However, the percentage of T cellsrelative to B cells was increased. The primary IgM antibodyresponse to the T-depen-dent antigen, sheep red blood cells,was decreased. Natural killer cell activity was reduced in responseto morphine, as was the phagocytic capacity of Kupffer cells.Host-resistance models of Listeria monocytogenes or Streptococcuspneumoniae showed an increased resistance following administrationof morphine. This increased host resistance, however, was notdue to an increase in antimicrobial action of sera obtainedfrom mice treated with morphine. The majority of morphine'seffects on the immune system exhibited a flat dose response,suggesting that these effects may be mediated secondarily throughcorticosterone.  相似文献   
14.
The relationship between maximum tolerated dose (MTD) and studysensitivity for detecting rodent carcinogenicity was evaluatedfor 216 chemicals found to be carcinogens in laboratory animalstudies conducted by the National Cancer Institute (NCI) andthe National Toxicology Program (NTP). Approximately two-thirdsof these rodent carcinogens would have been detected even withoutthe top dose (estimated MTD), but in many of these studies,some site-specific carcinogenic effects would have been missed.Among the remaining one-third of the rodent carcinogens thatrequired the top dose for statistical significance, approximately80% had numerically elevated rates of the same site-specifictumors at lower doses as well. Only 13 of the NCI/NTP rodentcarcinogens had increased tumor rates limited to the top dosefor all sites of carcinogenicity. Alternatively, of the 838site-specific carcinogenic effects observed in the NCI/NTP studies,447 (53%) would have been detected even without the top dose.Of the remaining effects, 75% (294/391) showed numerically elevatedsite-specific tumor rates at lower doses. Our evaluation indicatesthat most carcinogenic effects ob served at the top dose inrodent studies are also present (with reduced incidence thatmight or might not be statistically significant) at the lowerdoses typically employed (MTD, MTD).  相似文献   
15.
OBJECTIVE: Recent studies have concluded that Native North American children have higher proportions of overweight and obesity than children from the general North American population. This study presents anthropometric data on a representative sample of children from the Mohawk Nation that can be used for comparison with other Native American populations. DESIGN: This is a cross-sectional study comparing distributions of anthropometric characteristics of Mohawk children to the corresponding age and gender data from the Second National Health and Nutrition Examination Survey (NHANES II). Weight, height, triceps and subscapular skinfold thickness, and waist and hip circumferences were measured in 527 children. SUBJECTS/SETTING: All children in grades 1 to 6 (aged 6 to 11 years) in the 3 elementary schools of 2 Mohawk communities in Canada, for whom parental consent was obtained, were enrolled in the present study. There were no exclusion criteria. With a participation rate of 83%, the 527 children enrolled in this study represent an unbiased sample of the population from 2 Mohawk territories. RESULTS: Compared with children studied in NHANES II, Mohawk children were similar in height and triceps skinfolds but were generally heavier, had thicker subscapular skinfolds, and had greater waist and hip circumferences. These differences were greater in older children. Mohawk children who had extreme-high weight values compared with their population means were heavier than their NHANES II counterparts. APPLICATIONS/CONCLUSIONS: Results indicated that, on average, Mohawk children seem to be slightly heavier than children in NHANES II. Except for those with extreme overweight values, Mohawk children show less variation of weight and body mass index than children in NHANES II. Finally, overweight Mohawk children seem to be more likely to carry their excess body fat truncally, compared with overweight children from NHANES II. Health practitioners working with Native American populations should be careful when assessing childhood obesity. Simple comparisons of weight or body mass index with NHANES standards may lead to inappropriate risk assessments.  相似文献   
16.
17.
18.
Modified Pulmonary Vein Isolation in AF Ablation. Introduction: Pulmonary vein isolation (PVI) is the primary ablation therapy in patients with atrial fibrillation (AF). We hypothesized that high dominant frequency (DF) sites (AF nests during sinus rhythm [SR]) adjacent to the PV ostia are associated with the atrial substrate that maintains AF, and PVI incorporating the high‐frequency AF nests may have a higher efficacy. Methods and Results: In a prospective and randomized comparison, 126 symptomatic paroxysmal AF patients that underwent PVI were enrolled. We compared the efficacy of a modified PVI (ablation line: 1.0–1.5 cm from the PV ostium with encircling the AF nests [spectral analysis with DF >70 Hz during SR, Group II]) versus the anatomy‐guided conventional PVI (Group I). In Group II, the DF value along the PV ostium was lower than 70 Hz after the PVI. The primary endpoint was the freedom from symptomatic atrial arrhythmias after a single procedure. We also followed the autonomic function by a time‐domain analysis of the heart rate variability. In both groups, AF nests were observed and electric isolation was successfully obtained in all patients. With a mean duration of 16 ± 6.1 months of follow‐up, Group II had a higher single procedure efficacy without drugs (78.7% vs 66.1%, log‐rank test: P = 0.02), and fewer repeat procedures (6.6% vs 23%; P = 0.04), as compared to Group I. Conclusion: PVI incorporating the high frequency AF nests adjacent to the PV ostia had a better single procedure efficacy. (J Cardiovasc Electrophysiol, Vol. 23, pp. 1155–1162, November 2012)  相似文献   
19.
THE NATURE OF ARTHRITIS PAIN   总被引:1,自引:0,他引:1  
A modified version of the McGill Pain Questionnaire in visualanalogue format was used to evaluate the sensory, affectiveand evaluative intensities of pain experienced by 40 patientswith rheumatoid arthritis and 20 patients with degenerativearthritis. The affective component of the pain was found tobe more intense than the sensory component in all patients indicatingthe importance of emotional factors in the pain experience.The sensory aspects of the pain were more complex than the affectiveones reflecting the varied sources and combinations of somaticpathology. There were no significant differences found in theoverall pain experience between rheumatoid and degenerativearthritis. No differences were noted in the evaluative categoryof pain. Overall pain intensity increased with disease durationin both rheumatoid and degenerative arthritis. The relationshipof affective and sensory components of the pain experience didnot alter with duration of disease. KEY WORDS: Arthritis, Pain  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