全文获取类型
收费全文 | 32053篇 |
免费 | 2014篇 |
国内免费 | 152篇 |
专业分类
耳鼻咽喉 | 321篇 |
儿科学 | 781篇 |
妇产科学 | 799篇 |
基础医学 | 4740篇 |
口腔科学 | 1882篇 |
临床医学 | 2716篇 |
内科学 | 7171篇 |
皮肤病学 | 981篇 |
神经病学 | 2790篇 |
特种医学 | 529篇 |
外科学 | 2591篇 |
综合类 | 128篇 |
一般理论 | 21篇 |
预防医学 | 3649篇 |
眼科学 | 523篇 |
药学 | 2553篇 |
中国医学 | 192篇 |
肿瘤学 | 1852篇 |
出版年
2024年 | 42篇 |
2023年 | 381篇 |
2022年 | 869篇 |
2021年 | 1532篇 |
2020年 | 868篇 |
2019年 | 1249篇 |
2018年 | 1515篇 |
2017年 | 1009篇 |
2016年 | 961篇 |
2015年 | 1196篇 |
2014年 | 1570篇 |
2013年 | 1934篇 |
2012年 | 2956篇 |
2011年 | 3115篇 |
2010年 | 1545篇 |
2009年 | 1298篇 |
2008年 | 2140篇 |
2007年 | 2078篇 |
2006年 | 1801篇 |
2005年 | 1579篇 |
2004年 | 1369篇 |
2003年 | 1150篇 |
2002年 | 999篇 |
2001年 | 108篇 |
2000年 | 62篇 |
1999年 | 92篇 |
1998年 | 134篇 |
1997年 | 128篇 |
1996年 | 82篇 |
1995年 | 64篇 |
1994年 | 66篇 |
1993年 | 48篇 |
1992年 | 44篇 |
1991年 | 29篇 |
1990年 | 23篇 |
1989年 | 20篇 |
1988年 | 16篇 |
1987年 | 14篇 |
1986年 | 13篇 |
1985年 | 12篇 |
1984年 | 12篇 |
1983年 | 12篇 |
1982年 | 15篇 |
1981年 | 9篇 |
1980年 | 13篇 |
1978年 | 6篇 |
1976年 | 6篇 |
1975年 | 7篇 |
1973年 | 5篇 |
1972年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
992.
Ana Isabel Gualberto Buela-Casal Maria Bermúdez Rosario Cabello-Salas 《The Clinical neuropsychologist》2013,27(2):277-283
Several studies have shown that sleep fragmentation not only increases daytime sleepiness, but also deteriorates reaction time. Obstructive sleep apnea syndrome(OSAS)is characterized by interruptions in normal sleep patterns. Nasal Continuous Positive Airway Pressure(nCPAP)is the most frequently used treatment for OSAS. The objective of this investigation was to evaluate changes in daytime sleepiness levels and reaction time in apnea patients after nCPAP treatments of 1 and 3 months. The sample was composed of 51 obstructive sleep apnea patients(47 men and 4 women)with ages ranging between 30 and 65 years of age. Sleep apnea was diagnosed with a cardiorespiratory polygraph of the total hours of sleep. The Epworth Sleepiness Scale was used to assess daytime sleepiness. A BASIC software program was used to measure the simple perceptual reaction times in milliseconds. The results indicated statistically significant decreases in daytime sleepiness levels at 1 month(p?<?.000)and at 3 months(p?<?.000)of treatment. The results also showed statistically significant decreases in reaction times at one month(p?<?.000), as well as at 3 months(p?<?.000)of treatment. Results indicate an improvement in the vigilance levels of obstructive sleep apnea patients after 1 month and 3 months of nCPAP treatment. 相似文献
993.
Ana García-Blanco Pablo González-Valls Carmen Iranzo-Tatay Luis Rojo-Moreno Pilar Sierra Lorenzo Livianos 《International journal of psychiatry in clinical practice》2013,17(4):310-313
AbstractObjective: The determination of soft signs can be a conducive practice to understand the differential etiology between depression and anxiety. This study aims at examining malleolar hypoesthesia role in distinguishing between patients with generalised anxiety disorder (GAD) and major depression disorder (MDD).Methods: This study examines the presence of malleolar hypoesthesia in patients with GAD (n?=?47) compared to patients with MDD (n?=?48) and healthy individuals (controls; n?=?99). The Wartenberg wheel, a medical device for neurological use, was employed to determine the presence of hypoesthesia on both sides of the ankles.Results: The data revealed: i) MDD patients showed higher hypoesthesia than GAD patients (p?=?.008), ii) participants with hypoesthesia had higher anxiety and depression scores than participants without hypoesthesia (all p?<?.001) and iii) logistic regression model indicated that hypoesthesia can be a predictor of MDD relative to GAD diagnosis (Odds Ratio: 17.43 (1.40–217.09; p?=?.026)).Conclusions: Malleolar hypoesthesia was higher in MDD than GAD. The detection of hypoesthesia may help to investigate the differential etiology between MDD and GAD diagnosis. 相似文献
994.
Noelle B. Smith Ashton M. Steele Meara L. Weitzman Ana F. Trueba Alicia E. Meuret 《Archives of Suicide Research》2013,17(1):60-74
Self-directed disgust, a component of self-criticism, may present an important, yet unexplored emotion in the context of nonsuicidal self-injury (NSSI). The aim of this study was to examine the role of self-disgust in NSSI, specifically as a potential mediator in the relations between depression and NSSI as well as sexual abuse and NSSI, and to also better understand characteristics that might differentiate recent and past self-injurers. A total of 549 college students completed measures assessing NSSI, self-disgust, depression, anxiety sensitivity, and physical and sexual abuse. Results indicated self-disgust fully mediated the relation between depressive symptoms and NSSI status and partially mediated the relation between sexual abuse and NSSI status. Additionally, compared to past self-injurers (4.6%; n = 25), recent self-injurers (6.4%; n = 35) endorsed significantly higher self-disgust and depressive symptoms. Self-disgust may be an important component in NSSI and should be addressed in treatment. 相似文献
995.
ngel Gil-Agudo Ana de los Reyes-Guzmán Iris Dimbwadyo-Terrer Benito Peasco-Martín Alberto Bernal-Sahún Patricia López-Monteagudo Antonio del Ama-Espinosa José Luis Pons 《中国神经再生研究》2013,8(19):1773-1782
Upper limb function impairment is one of the most common sequelae of central nervous system in jury, especially in stroke patients and when spinal cord injury produces tetraplegia. Conventional assessment methods cannot provide objective evaluation of patient performance and the effec tiveness of therapies. The most common assessment tools are based on rating scales, which are inefficient when measuring small changes and can yield subjective bias. In this study, we designed an inertial sensorbased monitoring system composed of five sensors to measure and analyze the complex movements of the upper limbs, which are common in activities of daily living. We devel oped a kinematic model with nine degrees of freedom to analyze upper limb and head movements in three dimensions. This system was then validated using a commercial optoelectronic system. These findings suggest that an inertial sensorbased motion tracking system can be used in patients who have upper limb impairment through data integration with a virtual realitybased neurorehabili tation system. 相似文献
996.
Ana Helena Perosa Aripuan? S. A. Watanabe Sandra B. Guatura Ellen R. M. Silva Celso Granato Nancy Bellei 《Clinics (S?o Paulo, Brazil)》2013,68(9):1206-1209
OBJECTIVE:
This study evaluated the diagnostic performance of two methods for the detection of influenza virus in immunocompromised transplant patients.METHODS:
A total of 475 respiratory samples, 236 from patients in a hematopoietic stem cell transplantation program and 239 from kidney transplant patients, were analyzed by a direct fluorescence assay and the Centers for Disease Control real-time polymerase chain reaction protocol for influenza A and B detection.RESULTS:
Influenza detection using either method was 7.6% in the hematopoietic stem cell transplant group and 30.5% in the kidney transplant patient group. Influenza detection by real-time polymerase chain reaction yielded a higher positive rate compared with fluorescence than that reported by other studies, and this difference was more pronounced for influenza A. The fluorescence assay sensitivity, specificity, positive and negative predictive values, and kappa coefficient were 17.6%, 100%, 1, 0.83, and 0.256, respectively, and lower detection rates occurred in the kidney transplant patients.CONCLUSIONS:
The real-time polymerase chain reaction performance and the associated turnaround time for a large number of samples support the choice of this method for use in different routine diagnostic settings and influenza surveillance in high-risk patients. 相似文献997.
Manoel J. Teixeira Massako Okada Ana Sofia Cueva Moscoso Mariana Yumi Takahashi Puerta Lin T. Yeng Ricardo Galhardoni Sérgio Tengan Daniel Ciampi de Andrade 《Clinics (S?o Paulo, Brazil)》2013,68(7):1057-1060
OBJECTIVE:
This research was designed as a pilot proof-of-concept study to evaluate the use of low-dose methadone in post-herpetic neuralgia patients who remained refractory after first and second line post-herpetic neuralgia treatments and had indications for adding an opioid agent to their current drug regimens.METHODS:
This cross-over study was double blind and placebo controlled. Ten opioid naïve post-herpetic neuralgia patients received either methadone (5 mg bid) or placebo for three weeks, followed by a 15-day washout period and a second three-week treatment with either methadone or placebo, accordingly. Clinical evaluations were performed four times (before and after each three-week treatment period). The evaluations included the visual analogue scale, verbal category scale, daily activities scale, McGill pain questionnaire, adverse events profile, and evoked pain assessment. All patients provided written informed consent before being included in the study. ClinicalTrials.gov: NCT01752699RESULTS:
Methadone, when compared to placebo, did not significantly affect the intensity of spontaneous pain, as measured by the visual analogue scale. The intensity of spontaneous pain was significantly decreased after the methadone treatment compared to placebo on the category verbal scale (50% improved after the methadone treatment, none after the placebo, p = 0.031). Evoked pain was reduced under methadone compared to placebo (50% improved after the methadone treatment, none after the placebo, p = 0.031). Allodynia reduction correlated with sleep improvement (r = 0.67, p = 0.030) during the methadone treatment. The side effects profile was similar between both treatments.CONCLUSIONS:
Methadone seems to be safe and efficacious in post-herpetic neuralgia. It should be tried as an adjunctive treatment for post-herpetic neuralgia in larger prospective studies. 相似文献998.
Felipe de Souza Rossi Ana Cristina Zanon Yagui Luciana Branco Haddad Alice D'Agostini Deutsch Celso Moura Rebello 《Clinics (S?o Paulo, Brazil)》2013,68(3):345-350
OBJECTIVES:
Nasal continuous positive airway pressure is used as a standard of care after extubation in very-low-birth-weight infants. A pressure of 5 cmH2O is usually applied regardless of individual differences in lung compliance. Current methods for evaluation of lung compliance and air distribution in the lungs are thus imprecise for preterm infants. This study used electrical impedance tomography to determine the feasibility of evaluating the positive end-expiratory pressure level associated with a more homogeneous air distribution within the lungs before extubation.METHODS:
Ventilation homogeneity was defined by electrical impedance tomography as the ratio of ventilation between dependent and non-dependent lung areas. The best ventilation homogeneity was achieved when this ratio was equal to 1. Just before extubation, decremental expiratory pressure levels were applied (8, 7, 6 and 5 cmH20; 3 minutes each step), and the pressure that determined the best ventilation homogeneity was defined as the best positive end-expiratory pressure.RESULTS:
The best positive end-expiratory pressure value was 6.3±1.1 cmH20, and the mean continuous positive airway pressure applied after extubation was 5.2±0.4 cmH20 (p = 0.002). The extubation failure rate was 21.4%. X-Ray and blood gases after extubation were also checked.CONCLUSION:
This study demonstrates that electrical impedance tomography can be safely and successfully used in patients ready for extubation to suggest the best ventilation homogeneity, which is influenced by the level of expiratory pressure applied. In this feasibility study, the best lung compliance was found with pressure levels higher than the continuous positive airway pressure levels that are usually applied for routine extubation. 相似文献999.
Miriam Coelho Molck Társis Paiva Vieira Ilária Cristina Sgardioli Milena Simioni Ana Paula dos Santos Josiane Souza Fabíola Paoli Monteiro Vera Lúcia Gil-da-Silva-Lopes 《European journal of medical genetics》2013,56(9):515-520
The 22q11.2 Deletion Syndrome (22q11.2DS) is the most common microdeletion syndrome in humans, with a highly variable phenotype. This chromosomal region contains low copy repeat (LCR) sequences that mediate non-allelic homologous recombination which predispose to copy number abnormalities at this locus. This article describes three patients investigated for suspicion of 22q11.2DS presenting atypical copy number abnormalities overlapping or not with the common ~3 Mb deletion. They were investigated by G-banding karyotype, Multiplex-ligation dependent probe amplification (MLPA) and array Genomic Hibridization (aGH). Clinical and molecular data were compared with literature, in order to contribute to genotype–phenotype correlation. Atypical chromosomal abnormalities were detected: 3.6 Mb deletion at 22q11.21-q11.23 between LCRs B–F in patient 1 and approximately 1.5 Mb deletion at 22q11.21-q11.22 between LCRs D–E in patients 2 and 3. The breakpoints detected in patient 1 have not been previously described. These findings exemplify the complexity and genetic heterogeneity observed in 22q11.2 region and corroborates the idea that genetic modifiers contribute to the phenotypic variability observed in proximal and distal 22q11.2 deletion syndromes. 相似文献
1000.
Ana Carolina Fragoso Motta Cristiane Aparecida Nogueira Bataglion Maria Cristina Foss-Freitas Milton Cesar Foss Marilena Chinali Komesu 《Clinics (S?o Paulo, Brazil)》2013,68(3):427-430