全文获取类型
收费全文 | 37070篇 |
免费 | 3000篇 |
国内免费 | 100篇 |
专业分类
耳鼻咽喉 | 364篇 |
儿科学 | 1169篇 |
妇产科学 | 972篇 |
基础医学 | 5697篇 |
口腔科学 | 511篇 |
临床医学 | 5231篇 |
内科学 | 6617篇 |
皮肤病学 | 721篇 |
神经病学 | 4122篇 |
特种医学 | 845篇 |
外科学 | 3412篇 |
综合类 | 339篇 |
现状与发展 | 1篇 |
一般理论 | 42篇 |
预防医学 | 4028篇 |
眼科学 | 657篇 |
药学 | 2455篇 |
中国医学 | 46篇 |
肿瘤学 | 2941篇 |
出版年
2023年 | 263篇 |
2022年 | 385篇 |
2021年 | 938篇 |
2020年 | 623篇 |
2019年 | 968篇 |
2018年 | 1137篇 |
2017年 | 894篇 |
2016年 | 983篇 |
2015年 | 1008篇 |
2014年 | 1432篇 |
2013年 | 1855篇 |
2012年 | 2939篇 |
2011年 | 2998篇 |
2010年 | 1626篇 |
2009年 | 1493篇 |
2008年 | 2546篇 |
2007年 | 2615篇 |
2006年 | 2352篇 |
2005年 | 2469篇 |
2004年 | 2201篇 |
2003年 | 2036篇 |
2002年 | 1917篇 |
2001年 | 296篇 |
2000年 | 195篇 |
1999年 | 321篇 |
1998年 | 420篇 |
1997年 | 347篇 |
1996年 | 253篇 |
1995年 | 252篇 |
1994年 | 210篇 |
1993年 | 193篇 |
1992年 | 153篇 |
1991年 | 148篇 |
1990年 | 116篇 |
1989年 | 129篇 |
1988年 | 116篇 |
1987年 | 100篇 |
1986年 | 89篇 |
1985年 | 87篇 |
1984年 | 101篇 |
1983年 | 92篇 |
1982年 | 75篇 |
1981年 | 97篇 |
1980年 | 81篇 |
1979年 | 56篇 |
1978年 | 54篇 |
1977年 | 58篇 |
1976年 | 43篇 |
1974年 | 43篇 |
1972年 | 41篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Cardiac MIBG scintigraphy is a sensitive tool for detecting cardiac sympathetic denervation in Parkinson's disease. 总被引:5,自引:0,他引:5
Frédéric Courbon Christine Brefel-Courbon Claire Thalamas Marie-Jeanne Alibelli Isabelle Berry Jean-Louis Montastruc Olivier Rascol Jean-Michel Senard 《Movement disorders》2003,18(8):890-897
[(123)I]Metaiodobenzylguanidine ([(123)I]MIBG) cardiac scintigraphy could be helpful to differentiate Parkinson's disease (PD) from multiple system atrophy (MSA), demonstrating that, in PD with autonomic failure but not in MSA, there is a myocardial postganglionic sympathetic dysfunction. To investigate whether this method is more sensitive than standard autonomic testing to detect early involvement of sympathetic cardiac efferent, we analyse MIBG myocardial uptake in 8 PD patients with normal autonomic testing (nondysautonomia PD group, NDPD) in comparison with 10 PD patients with abnormal autonomic testing (dysautonomia PD group, DPD) and 10 MSA patients. Global MIBG uptake was assessed using the ratio of [(123)I]MIBG uptake in the heart to the upper mediastinum (H/M) on planar scintigraphic data. Regional MIBG uptake was determined on two single photon emission tomography scans in regions of the left ventricle. The mean H/M ratios were significantly different among the three groups (P < 0.0001). H/M ratios of both NDPD and DPD patients groups (H/M = 1.83 +/- 0.50 and 1.24 +/- 0.40, respectively) were significantly lower than in MSA patients (H/M = 2.52 +/- 0.60). However, in NDPD patients, H/M was significantly higher than in DPD patients. When compared to MSA patients, NDPD patients showed a regional reduction in MIBG uptake in all left ventricle regions markedly in the apex and the inferior wall. Our results suggest that MIBG myocardial scintigraphy (analysis of both H/M ratio and regional MIBG uptake) may be more sensitive than standard autonomic testing for the early detection of silent autonomic dysfunction in PD. 相似文献
92.
93.
94.
95.
Why should depression screening be conducted in chronically ill populations? Depression is a disabling illness and is very common among patients who have chronic illnesses. Despite its high prevalence in this patient population, depression often goes unrecognized. Having a plan for a population-based screening program for depression can not only identify patients who are at risk of depression, but can also help to foster early treatment and enhanced care for these patients. This article provides an overview of commonly-used depression screening tools and presents an example of how this might be carried out in a healthcare organization. 相似文献
96.
Epidural test dose and intravascular injection in obstetrics: sensitivity, specificity, and lowest effective dose. 总被引:4,自引:0,他引:4
The authors studied the sensitivity and specificity of several epidural test doses as markers of intravascular injection in laboring patients in a prospective double-blind, randomized study. Fifty-nine parturients were assigned randomly to receive an intravenous injection of either normal saline solution (3 mL, NS group) or 1.5% lidocaine with epinephrine 1:200,000 (1 mL, EPI-5 group; 2 mL, EPI-10 group; or 3 mL, EPI-15 group). The EPI-5 and EPI-10 doses were diluted to 3 mL volume with normal saline solution. All injections were given during uterine diastole. Maternal heart rate was monitored with a pulse oximeter. An observer who was unaware of the study treatment recorded the baseline and the peak maternal heart rate within the first minute after the injection and questioned the patient about tinnitus, dizziness, metallic taste, and palpitations. He then recorded his opinion as to whether the patient had received the saline or the test solution. Analysis of the maternal heart rate showed an average increase (baseline-to-peak criterion) of 8 +/- 10 beats/min (mean +/- SD) in the NS group. In the other groups, the increase was 21 +/- 8 (EPI-5 group), 31.5 +/- 13 (EPI-10 group), and 29 +/- 9 beats/min (EPI-15 group). A baseline-to-peak criterion of greater than 10 beats/min identified all intravascular injections in the EPI-15 (by design) and EPI-10 groups (15 of 15 and 14 of 14, respectively) with a sensitivity of 100%. Specificity was 73% (11 of 15 true negatives).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
97.
Explanations of cancer need to take into account developmental changes in children's cognitive and emotional abilities to understand illness. Children below 5 years of age are usually informed by parents, and older children by medical staff. Information tends to focus on details of treatments and procedures, and less on the seriousness of the disease and length of time involved. There are indications that early and honest information is associated with better behaviour and adjustment in the child, communication within the family and compliance with treatment, although methodological inadequacies in assessment of adjustment and knowledge of cancer limit the ability to generalize these findings. Communication with children should take into account developmental changes in children's ability to understand illness information. Communicators should also provide emotional support to deal with the threatening nature of this information. 相似文献
98.
Lynn Ware M.D. Dr. David Muram M.D. Christine L. Gale M.D. 《Sexuality and disability》1992,10(3):189-192
In some patients with mental retardation, a Q-tip pap smear obtained blindly from the upper vagina may be the only cytologic smear obtainable without subjecting the patient to heavy sedation or to examination under anesthesia. The efficacy of blind Q-tip smears has not been previously determined. Of 31 Q-tip smears obtained from patients with CIN, the Q-tip smear identified the abnormality in 10 (32%) patients. For those patients who will not submit to examination without anesthesia or sedation, routine screening with multiple smears, obtained on an annual basis has the potential to identify many cases of CIN which otherwise would not be identified at all, and in certain patients, this method outweighs the risks of heavy sedation or general anesthesia. Because of the greatly reduced sensitivity of the Q-tip pap, every effort should be made to help the patient and/or her family or guardian to understand the implications and risks of this method. However, if an examination under anesthesia is performed for other indications, a complete gynecologic examination and a direct smear should be obtained at that time. 相似文献
99.
An important methodological issue in depressionanalog research is whether individuals who scoreextremely low on self-report measures like the BeckDepression Inventory (BDI) should be included innondepressed control groups. Joiner, Schmidt, and Metalsky(1994) found that college students with BDI scores of 0or 1 evidenced a fake-good test taking style as measuredby the MMPI validity scales. The present study investigated whether very low BDI scores (BDI= 0 or 1; n = 21) might be associated with an elevatedpositive mood state, extreme optimism, positiveattributional style or social desirability. Resultsindicated that the very low scoring BDI subjects scoredhigher on social desirability than the low scoring group(BDI = 2 9, n = 63). Significant differences on mood,symptom and cognitive measures disappeared when social desirability was entered as a covariate.Findings support Kendall, Hollon, Beck, Hammen, andIngram's (1987) recommendation that subjects who score0 or 1 on the BDI should be excluded from a nondepressed control group. 相似文献
100.
David J Schretlen Cynthia A Munro James C Anthony Godfrey D Pearlson 《Journal of the International Neuropsychological Society》2003,9(6):864-870
Neuropsychologists often diagnose cerebral dysfunction based, in part, on marked variation in an individual's cognitive test performance. However, little is known about what constitutes the normal range of intraindividual variation. In this study, after excluding 54 individuals with significant health problems, we derived 32 z-transformed scores from 15 tests administered to 197 adult participants in a study of normal aging. The difference between each person's highest and lowest scores was computed to assess his or her maximum discrepancy (MD). The resulting MD values ranged from 1.6 to 6.1 meaning that the smallest MD shown by any person was 1.6 standard deviations (SDs) and the largest MD shown by any person was 6.1 SDs. Sixty-six percent of participants produced MD values that exceeded 3 SDs. Eliminating each person's highest and lowest test scores decreased their MDs, but 27% of the participants still produced MD values exceeding 3. Although MD values appeared to increase with age, adjusting test scores for age, which is standard in clinical practice, did not correct for this. These data reveal that marked intraindividual variability is very common in normal adults, and underscore the need to base diagnostic inferences on clinically recognizable patterns rather than psychometric variability alone. 相似文献