全文获取类型
收费全文 | 15635篇 |
免费 | 1112篇 |
国内免费 | 70篇 |
专业分类
耳鼻咽喉 | 265篇 |
儿科学 | 601篇 |
妇产科学 | 450篇 |
基础医学 | 1904篇 |
口腔科学 | 242篇 |
临床医学 | 1604篇 |
内科学 | 3516篇 |
皮肤病学 | 483篇 |
神经病学 | 1285篇 |
特种医学 | 513篇 |
外科学 | 2526篇 |
综合类 | 185篇 |
一般理论 | 20篇 |
预防医学 | 989篇 |
眼科学 | 341篇 |
药学 | 961篇 |
中国医学 | 32篇 |
肿瘤学 | 900篇 |
出版年
2023年 | 122篇 |
2022年 | 227篇 |
2021年 | 588篇 |
2020年 | 343篇 |
2019年 | 456篇 |
2018年 | 522篇 |
2017年 | 379篇 |
2016年 | 424篇 |
2015年 | 416篇 |
2014年 | 553篇 |
2013年 | 740篇 |
2012年 | 1061篇 |
2011年 | 1083篇 |
2010年 | 585篇 |
2009年 | 550篇 |
2008年 | 836篇 |
2007年 | 923篇 |
2006年 | 836篇 |
2005年 | 786篇 |
2004年 | 737篇 |
2003年 | 627篇 |
2002年 | 546篇 |
2001年 | 223篇 |
2000年 | 202篇 |
1999年 | 206篇 |
1998年 | 136篇 |
1997年 | 88篇 |
1996年 | 78篇 |
1995年 | 67篇 |
1994年 | 71篇 |
1993年 | 75篇 |
1992年 | 120篇 |
1991年 | 130篇 |
1990年 | 111篇 |
1989年 | 120篇 |
1988年 | 106篇 |
1987年 | 106篇 |
1986年 | 116篇 |
1985年 | 113篇 |
1984年 | 102篇 |
1983年 | 84篇 |
1982年 | 83篇 |
1981年 | 102篇 |
1980年 | 70篇 |
1979年 | 85篇 |
1978年 | 74篇 |
1977年 | 65篇 |
1975年 | 45篇 |
1974年 | 51篇 |
1972年 | 45篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Oleg Kleiner Jacob Mordehai Pavel Krugliak Zahavi Cohen 《European Journal of Trauma》2004,30(6):403-405
Background:
Cases of extrahepatic biliary tree trauma are not as common as other intraabdominal injuries and may pose a diagnostic and therapeutic challenge. 相似文献12.
13.
The relationship between the amount of inhaled steroids delivered from pressurized metered-dose inhalers used with their recommended holding chambers and age of the patients using these devices was studied in an open randomised cross-over filter study. We recruited 1-2-month-old healthy infants (n = 21), 2-3-year-old asthmatics (n = 13), 4-6-year-old asthmatics (n = 15), and 10-15-year-old asthmatics (n = 20). Each child inhaled two puffs, administered by a single investigator, of both budesonide through Nebuchamber and fluticasone propionate through Babyhaler, on two occasions. Moreover, the 4-6-year-old group inhaled via both facemask and mouthpiece. Drug, collected on a filter interposed between holding chamber and patient, was analysed by high performance liquid chromatography. Filter dose, expressed in percent of the nominal dose, was analysed in a mixed effect linear regression model with age group, holding chamber and inhalation interface (facemask or mouthpiece) as fixed effects and subject as random effect. Filter dose from both holding chambers increased significantly with age, from 3% with Babyhaler and 7% with Nebuchamber in the youngest children, to 40-41% with both holding chambers in adolescents. Nebuchamber delivered more drug than Babyhaler (p = 0.002), but variability in drug delivery (about 11%) was similar between holding chambers. Filter dose decreased from 35% to 22% with Babyhaler, and from 42% to 27% with Nebuchamber when using a mouthpiece rather than a facemask (p < 0.0001). Delivery of inhaled steroids used with their recommended holding chambers depends from age and holding chamber, but also from the inhalation interface. Lung deposition and clinical studies comparing inhalation from holding chambers with mouthpiece and facemask are urgently required. 相似文献
14.
Antonio C Pastorino Rejane D C Rimazza Cláudio Leone Ana Paula M Castro Dirceu Solé Cristina M A Jacob 《The Journal of asthma》2006,43(9):695-700
BACKGROUND: Identify risk factors for asthma in adolescents from S?o Paulo, Brazil. METHODS: total of 528 adolescents (141 asthmatics, 387 control subjects) from the ISAAC study (phase III) were submitted to a complementary questionnaire to evaluate risk factors, through response to questions regarding personal history, environment, and diet and an agreement to undergo the skin prick test (SPT) for aeroallergens. RESULTS: Positive SPT to at least one allergen occurred in 49.4% adolescents. The risk factors for asthma were: prematurity (OR: 3.84, 95% CI: 1.54-9.64), rhinitis (OR: 3.18, 95% CI: 1.71-5.91), positivity in the SPT (OR: 2.81, 95% CI: 1.48-5.32), eczema in characteristic skin-folds (OR: 2.86, 95% CI: 1.13-7.26), and an allergic mother (OR: 2.01, 95% CI: 1.02-3.93). The consumption of cooked vegetables was a protective factor for asthma (OR: 0.37, 95% CI: 0.18-0.79) CONCLUSIONS: Asthma is a multifatorial disease. An allergic mother, aeroallergen sensitization, rhinitis, eczema and prematurity were considered risk factors and the consumption of cooked vegetables was considered a protective factor for asthma in this population. 相似文献
15.
STELLA Frunza Patten M.D. Jacob W.E. Dijkstra M.D. 《International journal of dermatology》1994,33(12):836-842
16.
E Sarfati L Jacob J M Servant B d'Acremont E Roland T Ghidalia M Celerier 《The Journal of thoracic and cardiovascular surgery》1992,103(3):412-413
Between 1968 and 1988, 679 patients were hospitalized for ingestion of caustic substances, and 87 had severe caustic burns of the entire esophagus, together with panparietal necrosis. Twenty-one of them had tracheobronchial necrosis with perforation. Fifteen have not been operated on; six have had operations, with success in four. We describe an original technique for repairing these tracheobronchial perforations with a pulmonary patch. 相似文献
17.
Jansen Jacob G.; van Teijlingen Corrie M. M.; MOHN Georges R.; van Zeeland Albert A.; Vrieling Harry 《Mutagenesis》1994,9(5):417-421
Spectra of N-ethyl-N-nitrosourea (ENU)-induced mutations differwidely among various in vitro and in vivo mutational systems.To investigate possible reasons for these differences, a mutationalsystem is needed in which the same target gene is used for comparisonin the same type of cells in vitro and in vivo. In the presentstudy, this was achieved by analysing at the molecular level35 hprt mutant rat fibroblast clones obtained from cell populationsexposed in vitro to ENU and comparing the mutational spectrumwith the previously determined spectrum of ENU-induced hprtmutants in the same target cells exposed in vivo. Twenty-eightmutants contained a single base pair alteration in the hprtcoding sequence. Most of these changes were found at AT basepairs (19/28), the AT to TA transversion being the most frequentkind of mutation (12/19), which is probably caused by O2-ethylthymine.Transversions at AT base pairs showed all mutated T's to belocated in the nontranscribed strand of the hprt gene, suggestinga strand specific fixation of mutations induced by O2-ethylthymine,which appears to be a general feature of ENU- and ENNG-inducedhprt mutations in mammalian cells. GC to AT transitions, probablycaused by O6-ethylguanine, were detected at a lower frequency(7/28). This in vitro mutational spectrum was very similar tothat of the same target cells exposed in vivo to ENU. A comparisonof the mutational spectra in AGT-proficient and AGT-deficientrodent cells exposed to ethylating agents showed that in contrastto the situation in AGT-proficient rat fibroblasts, GC to ATbase pair changes (and not AT to TA) are the predominant mutationsin AGT-deficient hamster cells.
4To whom correspondence should be addressed 相似文献
18.
Benjamin Volovitz Jacob Amir Hagit Malik Maya Lerman Itzhak Varsano 《The Journal of asthma》1994,31(1):27-34
Administration of theophylline to asthmatic children is frequently associated with an adverse influence on their behavior. The efficacy and behavioral effects of the administration of high-dose theophylline (T) and ketotifen (K) in various combinations were evaluated prospectively in a double-blind, placebo controlled study in 55 children with moderately severe perennial asthma. During a baseline period of 2 weeks, theophylline (serum level of 10-20 μg/ml) was administered to all the children. After this period the patients were randomly allocated into four comparable groups. The children were treated during a 12-week period with: T + K-Placebo (T group); T + K (T + K group); half-dose T + K (T/ 2 + K group); or placebo of both T and K (P group). During the 12-week treatment period, as compared to the baseline period, only the three groups of children who received active therapy (T + P, T + K, T/2 + K) showed a similar reduction in the number of days with asthmatic symptomatology, improvement of the total asthmatic symptoms score, and increased PEFR. The behavioral activity of the children (assessed by the Conner's rating scale) improved significantly only in the groups receiving placebo or T/2 + K. The results of this study suggest that a combination therapy of half the recommended therapeutic dose of theophylline with ketotifen can be clinically as effective as therapy with a full dose of theophylline, but with significantly less adverse behavioral effects. 相似文献
19.
Raffael Kalisch Mirjam Schubert Wolfgang Jacob Melanie S Kessler Rosa Hemauer Alexandra Wigger Rainer Landgraf Dorothee P Auer 《Neuropsychopharmacology》2006,31(5):925-932
In depressed patients as well as healthy controls, a positive relationship between hippocampal volume and trait anxiety has been reported. This study sought to explore the possible inter-relation between hippocampal volume and trait anxiety further. Magnetic resonance imaging at 7 T was used to measure hippocampal volumes in a rat model of extremes in trait anxiety (experiment 1) and in a Wistar population with normal anxiety-related behavior (experiment 2). In addition to anxiety-related behavior, potentially confounding factors (depression-like, exploratory, and locomotor behavior) were assessed. Experiment 1 globally supported the hypothesis of a positive relationship between hippocampus volume and trait anxiety but did not allow for ruling out possible confounds arising from cosegregation of other behavioral traits. Experiment 2 yielded strong evidence for a negative relationship which was specific for trait anxiety. Thus, the relationship between hippocampal volume and anxiety may be more complex than expected. Interestingly, anxiety-related behavior in experiment 2 had a stronger influence on hippocampal volume than depression-like behavior. In the light of hippocampal volume loss in anxiety disorder and frequent comorbidity of anxiety and depression, this finding suggests that further research into the relationship between anxiety and hippocampal volume may be critical for understanding hippocampal contributions to normal and pathological behavior. 相似文献
20.