全文获取类型
收费全文 | 765篇 |
免费 | 38篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 12篇 |
妇产科学 | 14篇 |
基础医学 | 147篇 |
口腔科学 | 3篇 |
临床医学 | 70篇 |
内科学 | 148篇 |
皮肤病学 | 4篇 |
神经病学 | 49篇 |
特种医学 | 51篇 |
外科学 | 97篇 |
综合类 | 2篇 |
预防医学 | 73篇 |
眼科学 | 7篇 |
药学 | 44篇 |
肿瘤学 | 81篇 |
出版年
2023年 | 3篇 |
2022年 | 4篇 |
2021年 | 31篇 |
2020年 | 6篇 |
2019年 | 21篇 |
2018年 | 18篇 |
2017年 | 7篇 |
2016年 | 10篇 |
2015年 | 19篇 |
2014年 | 27篇 |
2013年 | 33篇 |
2012年 | 44篇 |
2011年 | 52篇 |
2010年 | 40篇 |
2009年 | 30篇 |
2008年 | 49篇 |
2007年 | 50篇 |
2006年 | 43篇 |
2005年 | 34篇 |
2004年 | 30篇 |
2003年 | 27篇 |
2002年 | 33篇 |
2001年 | 20篇 |
2000年 | 8篇 |
1999年 | 8篇 |
1998年 | 11篇 |
1997年 | 4篇 |
1996年 | 12篇 |
1995年 | 8篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 10篇 |
1991年 | 11篇 |
1990年 | 7篇 |
1989年 | 12篇 |
1988年 | 12篇 |
1987年 | 10篇 |
1986年 | 13篇 |
1985年 | 9篇 |
1984年 | 6篇 |
1983年 | 6篇 |
1982年 | 3篇 |
1981年 | 3篇 |
1980年 | 6篇 |
1978年 | 1篇 |
1976年 | 2篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1972年 | 3篇 |
1967年 | 1篇 |
排序方式: 共有803条查询结果,搜索用时 15 毫秒
1.
Helen J. Michielsen Marcel A. Croon Tineke M. Willemsen Jolanda De Vries Guus L. Van Heck 《Stress and health》2007,23(2):121-130
The main objective of this study was to examine the psychosocial stress model developed by Taylor and Aspinwall with emotional exhaustion as the outcome variable. Respondents, 409 men and 346 women, who had a paid job for at least 20 hours per week, completed questionnaires concerning demographic variables, personality, temperament, work pressure, workload, perceived social support, appraisal, coping, and emotional exhaustion. Structural equation analyses provided only partial support for the validity of the model. First, on theoretical and statistical grounds, one more path linking external resources to social support was added. Second, contrary to expectations, coping styles did not predict emotional exhaustion. To conclude, when coping is measured retrospectively, it does not add to our understanding of emotional exhaustion. It is suggested that future studies should be longitudinal and include objective measures of stressors and psychosocial health outcomes in addition to self‐reports. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
2.
In order to demonstrate a possible complement activation during early bronchospastic reaction in asthma, we have measured plasmatic C3d (a split product of C3) and the C3d/C3 index, both of which are sensitive indices of complement activation. Twenty-nine allergenic bronchial challenge tests were accomplished, with an absence of response in six cases, an early reaction in sixteen cases and a dual reaction in seven cases. Changes in plasmatic C3d or C3d/C3 five min after an early reaction, or five min after the last dose of allergen (in the six cases without bronchial response) were insignificant. However, complement activation in the lungs during asthmatic reaction cannot be completely excluded without studies using the bronchoalveolar technique. 相似文献
3.
C Balestra J Duchateau K Hainaut 《Electroencephalography and clinical neurophysiology》1992,85(1):46-52
The effects of fatigue on the electromyographic (EMG) reflex activities were compared during sustained voluntary contractions and contractions evoked by electrical stimulation (30 Hz) in the human first dorsal interosseus (FDI). Short latency (SL), medium latency (ML) and long latency (LL) reflex responses to a ramp-and-hold stretch of the muscle were recorded and analysed in 27 healthy subjects of both sexes. The amplitude of the reflex components was normalized as function of the amplitude of the surface action potential (SAP) recorded in response to the supramaximal stimulation of the motor nerve. The results indicate that for a similar reduction of force, SL and ML are significantly reduced after fatigue induced by voluntary contractions but they are not when the fatigue test is performed by electrical stimulation at the motor point. In voluntary fatigue experiments, the LL component showed no significant decrease below control values, but an enhancement was observed during electrically evoked contraction. This enhancement remained above control values for at least 15 min during the recovery period, whereas SL and ML decreases returned to control within 5 min after the fatigue tests. The electrical stimulation applied to the skin overlying the FDI at an intensity lower than the motor threshold did not affect SL and ML, but enhanced LL for about 15 min. On the contrary, the anaesthesia of the skin overlying the FDI induced a decrease in LL without significant change of SL and ML. It is concluded that muscle reflex fatigue is present during sustained voluntary contractions and decreases SL and ML responses to quick stretches.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
4.
Patients with chronic pain constitute a major problem for the surgeon as the cause of their pain is often difficult to diagnose and is only rarely a well circumscribed lesion which is amenable to surgical or other treatment. We report a case of chronic pain due to a vascular leiomyoma beneath the deep fascia of the leg. Angioleiomyomas are rare tumours that are usually found in the subcutaneous tissue. 相似文献
5.
P. J. Griffiths J. J. Duchateau Y. Maeda J. D. Potter C. C. Ashley 《Pflügers Archiv : European journal of physiology》1990,415(5):554-565
Intact muscle fibres fromBalanus nubilus develop tensions of up to 600 kN sd m−2 during electrical stimulation. The rise of tension occurs with a half-time (177 ms at 12° C) about fivefold longer than that
of tetanised frog muscle at the same temperature. The response of myofibrillar bundles to a rapid stretch resembles that of
frog muscle but has a yo value (i.e. the size of an instantaneous release necessary to just discharge tension) which is ca. 2.5 times smaller, and
phase 2 of the tension transient (the “quick phase”) occurs at a rate comparable to that of frog muscle. In contrast, the
ATPase activity (0.018 mmoles · kg wet weight−1 · s−1) of this preparation and its maximum shortening velocity (0.15–0.16 muscle lengths · s−1) are both at least fivefold slower than frog muscle. These findings can be accounted for by a cross-bridge cycle in barnacle
muscle in which events prior and subsequent to the tension generating step(s) occur at a rate at least fivefold slower than
comparable steps in frog muscle, but the step(s) associated with tension development occur at similar rates in the two preparations.
Since the rate of mechanical relaxation in barnacle muscle is modified in the presence of intracellular calcium buffers and
by depolarisation-induced elevation of the free calcium during the relaxation phase, it is proposed that the time course of
relaxation is not determined exclusively by the kinetics of the cross-bridge cycle, but is also dependent on the free calcium
concentration during relaxation. 相似文献
6.
Immunologic Research - Peripheral human blood lymphocytes from healthy blood donors were investigated in vitro to observe the influence of different doses of thymopentin on nonstimulated... 相似文献
7.
Rapid detection of Candida albicans in clinical blood samples by using a TaqMan-based PCR assay 总被引:2,自引:0,他引:2 下载免费PDF全文
Maaroufi Y Heymans C De Bruyne JM Duchateau V Rodriguez-Villalobos H Aoun M Crokaert F 《Journal of clinical microbiology》2003,41(7):3293-3298
We describe a rapid and reproducible PCR assay for quantitation of the Candida albicans ribosomal DNA (rDNA) in clinical blood samples based on the TaqMan principle (Applied Biosystems), in which a signal is generated by cleavage of a template-specific probe during amplification. We used two fluorogenic probes based on universal, fungus-specific primers, one for the detection of C. albicans species DNA and one for the detection of all Candida genus DNA. C. albicans blastoconidia mixed with whole blood in a titration experiment yielded a linear PCR signal over a range of 3 orders of magnitude. The TaqMan-based PCR assay for C. albicans exhibited a low limit of detection (5 CFU/ml of blood) and an excellent reproducibility (96 to 99%). While the C. albicans species-specific probe had 100% specificity for C. albicans, all Candida genus-specific probes cross-reacted with other organisms likely to coinfect patients with C. albicans infections. On the basis of these data, we determined the C. albicans loads with a species-specific probe from 122 blood samples from 61 hematology or oncology patients with clinically proven or suspected systemic Candida infections. Eleven positive samples exhibited a wide range of C. albicans loads, extending from 5 to 100,475 CFU/ml of blood. The sensitivity and specificity of the present assay were 100 and 97%, respectively, compared with the results of blood culture. These data indicate that the TaqMan-based PCR assay for quantitation of C. albicans with a species-specific probe provides an attractive alternative for the identification and quantitation of C. albicans rDNA in pure cultures and blood samples. 相似文献
8.
Patrick Feiereisen Jacques Duchateau K. Hainaut 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》1997,114(1):117-123
The recruitment order of motor units (MU) was compared during voluntary and electrically induced contractions. With the use
of spike-triggered averaging, a total of 302 MUs with recruitment thresholds ranging from 1% to 88% of maximal voluntary contraction
were recorded in the human tibialis anterior muscle in five subjects. The mean (±SD) MU force was 98.3±93.3 mN (mean torque
16.8±15.9 mNm) and the mean contraction time (CT) 46.2±12.7 ms. The correlation coefficients (r) between MU twitch force and CT versus the recruitment threshold in voluntary contractions were +0.68 and –0.38 (P<0.001), respectively. In voluntary contractions, MUs were recruited in order of increasing size except for only 6% of the
cases; whereas, during transcutaneous electrical stimulation (ES) at the muscle motor point, MU pairs showed a reversal of
recruitment order in 28% and 35% of the observations, respectively, when the pulse durations were 1.0 ms or 0.1 ms. This recruitment
reversal during ES was not related to the magnitude of the difference in voluntary recruitment thresholds between MUs. It
is concluded that if the reversal of MU recruitment observed during ES is biophysically controlled by differences in their
nerve axon input impedance, in percutaneous stimulation at the motor point, other factors such as the size and the morphological
organisation of the axonal branches can also influence the order of activation.
Received: 24 May 1996 / Accepted: 30 September 1996 相似文献
9.
Adedotun J. Owolabi Idowu O. Senbanjo Kazeem A. Oshikoya Jos Boekhorst Robyn T. Eijlander Guus A. M. Kortman Jeske H. J. Hageman Folake Samuel Alida Melse-Boonstra Anne Schaafsma 《Nutrients》2021,13(5)
Prevalence of anaemia among Nigerian toddlers is reported to be high, and may cause significant morbidity, affects brain development and function, and results in weakness and fatigue. Although, iron fortification can reduce anaemia, yet the effect on gut microbiota is unclear. This open-label randomised study in anaemic malnourished Nigerian toddlers aimed to decrease anaemia without affecting pathogenic gut bacteria using a multi-nutrient fortified dairy-based drink. The test product was provided daily in different amounts (200, 400 or 600 mL, supplying 2.24, 4.48 and 6.72 mg of elemental iron, respectively) for 6 months. Haemoglobin, ferritin, and C-reactive protein concentrations were measured to determine anaemia, iron deficiency (ID) and iron deficiency anaemia (IDA) prevalence. Faecal samples were collected to analyse gut microbiota composition. All three dosages reduced anaemia prevalence, to 47%, 27% and 18%, respectively. ID and IDA prevalence was low and did not significantly decrease over time. Regarding gut microbiota, Enterobacteriaceae decreased over time without differences between groups, whereas Bifidobacteriaceae and pathogenic E. coli were not affected. In conclusion, the multi-nutrient fortified dairy-based drink reduced anaemia in a dose-dependent way, without stimulating intestinal potential pathogenic bacteria, and thus appears to be safe and effective in treating anaemia in Nigerian toddlers. 相似文献
10.
Guus MJ Bökkerink Maja Joosten Erik Leijte Maud YA Lindeboom Ivo de Blaauw Sanne MBI Botden 《Journal of pediatric surgery》2021,56(3):465-470
BackgroundMinimal invasive surgery (MIS) is increasingly used for the correction of congenital diaphragmatic hernia (CDH) and esophageal atresia (EA). It is important to master these complex procedures, preferably preclinically, to avoid complications. The aim of this study was to validate recently developed models to train these MIS procedures preclinically.MethodsTwo low cost, reproducible models (one for CDH and one for EA) were validated during several pediatric surgical conferences and training sessions (January 2017–December 2018), used in either the LaparoscopyBoxx or EoSim simulator. Participants used one or both models and completed a questionnaire regarding their opinion on realism (face validity) and didactic value (content validity), rated on a five-point-Likert scale.ResultsOf all 60 participants enrolled, 44 evaluated the EA model. All items were evaluated as significantly better than neutral, with means ranging from 3.7 to 4.1 (p < 0.001). The CDH model was evaluated by 48 participants. All items scored significantly better than neutral (means 3.5–3.9, p < 0.001), with exception of the haptics of the simulated diaphragm (mean 3.3, p = 0.054). Both models were considered a potent training tool (means 3.9).ConclusionThese readily available and low budget models are considered a valid and potent training tool by both experts and target group participants.Type of studyProspective study.Level of evidenceLevel II. 相似文献