全文获取类型
收费全文 | 373篇 |
免费 | 13篇 |
国内免费 | 1篇 |
专业分类
儿科学 | 8篇 |
妇产科学 | 7篇 |
基础医学 | 62篇 |
口腔科学 | 4篇 |
临床医学 | 49篇 |
内科学 | 63篇 |
皮肤病学 | 5篇 |
神经病学 | 62篇 |
特种医学 | 24篇 |
外科学 | 36篇 |
综合类 | 1篇 |
预防医学 | 37篇 |
眼科学 | 3篇 |
药学 | 21篇 |
肿瘤学 | 5篇 |
出版年
2023年 | 2篇 |
2022年 | 3篇 |
2021年 | 10篇 |
2020年 | 2篇 |
2019年 | 5篇 |
2018年 | 6篇 |
2017年 | 5篇 |
2016年 | 8篇 |
2015年 | 5篇 |
2014年 | 15篇 |
2013年 | 25篇 |
2012年 | 28篇 |
2011年 | 40篇 |
2010年 | 25篇 |
2009年 | 17篇 |
2008年 | 28篇 |
2007年 | 26篇 |
2006年 | 25篇 |
2005年 | 21篇 |
2004年 | 20篇 |
2003年 | 17篇 |
2002年 | 16篇 |
2001年 | 5篇 |
2000年 | 2篇 |
1999年 | 4篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1995年 | 2篇 |
1993年 | 1篇 |
1992年 | 3篇 |
1990年 | 5篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 3篇 |
1984年 | 2篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1974年 | 1篇 |
1930年 | 2篇 |
排序方式: 共有387条查询结果,搜索用时 46 毫秒
11.
Ahmed K. Ibrahim Shona J. Kelly Clive E. Adams Cris Glazebrook 《Journal of psychiatric research》2013
Background
Depression is a common health problem, ranking third after cardiac and respiratory diseases as a major cause of disability. There is evidence to suggest that university students are at higher risk of depression, despite being a socially advantaged population, but the reported rates have shown wide variability across settings.Purpose
To explore the prevalence of depression in university students.Method
PubMed, PsycINFO, BioMed Central and Medline were searched to identify studies published between 1990 and 2010 reporting on depression prevalence among university students. Searches used a combination of the terms depression, depressive symptoms, depressive disorders, prevalence, university students, college students, undergraduate students, adolescents and/or young adults. Studies were evaluated with a quality rating.Results
Twenty-four articles were identified that met the inclusion and exclusion criteria. Reported prevalence rates ranged from 10% to 85% with a weighted mean prevalence of 30.6%.Conclusions
The results suggest that university students experience rates of depression that are substantially higher than those found in the general population. Study quality has not improved since 1990. 相似文献12.
OBJECTIVE: To address the current lack of psychometrically sound measures of beliefs regarding the consequences of obesity and ideal weight that has limited research to-date. METHODS: In phase one, interviews with 22 healthy-weight, overweight and obese individuals were conducted, subjected to theme analysis and used to develop 40 items. In phase two, unsound items were removed following item and principal components analyses of data from a community sample of 188 participants. In phase three, the items selected in phase two were administered to a second workforce population (n=302) to ensure their excellent psychometric properties were stable. In phase four, data were collected from 104 obese clinic attendees to establish the subscales' construct validity. RESULTS: The resultant Obesity Beliefs Scale (OBS) is comprised of three short, reliable, unidimensional and valid subscales written in language suitable for individuals aged 12 years and above. CONCLUSION: The OBS is a psychometrically sound measure of beliefs regarding the consequences obesity and ideal weight. PRACTICE IMPLICATIONS: The OBS has the potential to play a key role in prospective research designed to fully determine the role of beliefs in weight control behaviour. It can also be used to target and assess health education interventions. 相似文献
13.
Di Fabio RP Zampieri C Tuite P 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》2007,178(3):351-362
The relative sparing of visual fixation in parallel with disruption of saccade function in progressive supranuclear palsy
(PSP) creates a unique human model for the study of gaze-shift strategies which are adopted when vertical gaze palsy impairs
primarily the eye-movement component of gaze control. It was hypothesized that people with PSP would rely on head pitch as
a primary component of gaze shift during a platform stepping task and that there would be a predominance of fixation behavior
(counter rotation of the eyes during head pitch) while attempting a down-gaze shift. Fourteen subjects with probable and 5
subjects with possible PSP participated in two experiments to measure visual fixation and gaze shift on the same continuum
(using a derived vertical gaze fixation score, vGFS). Experiment #1 required gaze fixation during passive head pitch at 0.1–0.2 Hz,
whereas experiment #2 required gaze shifts during a continuous platform step on, over, and off task. The primary gaze-shift
strategy involved pitching the head downward to compensate for a loss in vertical saccade function. This strategy produced
head pitch velocity that leads vertical eye velocity on the order of 200–500 ms. Gaze shifts during platform stepping showed
greater fixation suppression (e.g., lower vGFS) in both groups of PSP compared to the visual stabilization task, but some
subjects showed “fixation intrusion” during attempted gaze shift. The amount of eye movement was relatively constant when
corrected for orbit height, whereas the extent of head pitch varied in proportion to the task demands. The mechanism controlling
gaze in PSP, therefore appears to modulate head pitch independently of eye movement, but the gaze strategy seems dependent
upon the extent of gaze dysfunction. These findings support the view that the desired gaze signal is parsed into separate
eye and head pathways upstream from the burst neurons. 相似文献
14.
15.
Cláudia Brito Margareth Crisóstomo Portela Mauricio Teixeira Leite de Vasconcellos 《Revista de saúde pública》2014,48(2):284-295
OBJECTIVE
To analyze factors associated with persistence to breast cancer hormone therapy in order to contribute to the quality of care improvement.METHODS
Retrospective longitudinal study, based on secondary data. A cohort of 5,861 women with breast cancer registered in different datasets of the Brazilian National Cancer Institute and the Brazilian Unified Health System were analyzed. All women were treated at this hospital, which provides free medication, and the follow-up period was from January 2004 to October 2010. Sociodemographic, behavioral, and clinical variables, as well as aspects of lifestyle and health care, were considered in the explanation of variations in the persistence to hormone therapy, applying the Kaplan-Meier method and the Cox proportional hazard model.RESULTS
Overall persistence to hormone therapy was 79.0% at the end of the first year, and 31.0% in five years of treatment. The risk of discontinuing hormone therapy was higher among women under 35 years old, with more advanced disease (stages III and IV), alcohol drinkers, those undergoing chemotherapy, and for each additional hospitalization, exam performed, and month between diagnosis and beginning of treatment. In the opposite direction, the risk of discontinuity was lower among women who had at least finished high school, those with partner, with a family history of cancer, those who had undergone breast surgery, and who had outpatient visits to a Mastologist, and a Clinical Oncologist.CONCLUSIONS
The majority of the women with breast cancer (69.0%) do not persist with hormone treatment for the five years recommended, increasing the risk of inadequate clinical results. The results show aspects of care that can provide better results. 相似文献16.
Seema Kalra Alan Silman Gulsen Akman-Demir Saeed Bohlega Afshin Borhani-Haghighi Cris S. Constantinescu Habib Houman Alfred Mahr Carlos Salvarani Petros P. Sfikakis Aksel Siva Adnan Al-Araji 《Journal of neurology》2014,261(9):1662-1676
Neuro-Behçet’s disease (NBD) is one of the more serious manifestations of Behçet’s disease (BD), which is a relapsing inflammatory multisystem disease with an interesting epidemiology. Though NBD is relatively uncommon, being potentially treatable, neurologists need to consider it in the differential diagnosis of inflammatory, infective, or demyelinating CNS disorders. Evidence-based information on key issues of NBD diagnosis and management is scarce, and planning for such studies is challenging. We therefore initiated this project to develop expert consensus recommendations that might be helpful to neurologists and other clinicians, created through an extensive literature review and wide consultations with an international advisory panel, followed by a Delphi exercise. We agreed on consensus criteria for the diagnosis of NBD with two levels of certainty in addition to recommendations on when to consider NBD in a neurological patient, and on the use of various paraclinical tests. The management recommendations included treatment of the parenchymal NBD and cerebral venous thrombosis, the use of disease modifying therapies, prognostic factors, outcome measures, and headache in BD. Future studies are needed to validate the proposed criteria and provide evidence-based treatments. 相似文献
17.
Viola Kooij Nicky Boontje Ruud Zaremba Kornelia Jaquet Cris dos Remedios Ger J. M. Stienen Jolanda van der Velden 《Basic research in cardiology》2010,105(2):289-300
Previous studies indicated that the increase in protein kinase C (PKC)-mediated myofilament protein phosphorylation observed
in failing myocardium might be detrimental for contractile function. This study was designed to reveal and compare the effects
of PKCα- and PKCε-mediated phosphorylation on myofilament function in human myocardium. Isometric force was measured at different
[Ca2+] in single permeabilized cardiomyocytes from failing human left ventricular tissue. Activated PKCα and PKCε equally reduced
Ca2+ sensitivity in failing cardiomyocytes (ΔpCa50 = 0.08 ± 0.01). Both PKC isoforms increased phosphorylation of troponin I- (cTnI) and myosin binding protein C (cMyBP-C)
in failing cardiomyocytes. Subsequent incubation of failing cardiomyocytes with the catalytic subunit of protein kinase A
(PKA) resulted in a further reduction in Ca2+ sensitivity, indicating that the effects of both PKC isoforms were not caused by cross-phosphorylation of PKA sites. Both
isozymes showed no effects on maximal force and only PKCα resulted in a modest significant reduction in passive force. Effects
of PKCα were only minor in donor cardiomyocytes, presumably because of already saturated cTnI and cMyBP-C phosphorylation
levels. Donor tissue could therefore be used as a tool to reveal the functional effects of troponin T (cTnT) phosphorylation
by PKCα. Massive dephosphorylation of cTnT with alkaline phosphatase increased Ca2+ sensitivity. Subsequently, PKCα treatment of donor cardiomyocytes reduced Ca2+ sensitivity (ΔpCa50 = 0.08 ± 0.02) and solely increased phosphorylation of cTnT, but did not affect maximal and passive force. PKCα- and PKCε-mediated
phosphorylation of cMyBP-C and cTnI as well as cTnT decrease myofilament Ca2+ sensitivity and may thereby reduce contractility and enhance relaxation of human myocardium. 相似文献
18.
19.
20.
Escosteguy CC Portela MC Medronho Rde A Vasconcellos MT 《Cadernos de saúde pública / Ministério da Saúde, Funda??o Oswaldo Cruz, Escola Nacional de Saúde Pública》2005,21(4):1065-1076
The objective of this study was to analyze the usefulness of the Brazilian Hospital Information System (SIH) in comparison to medical records to study factors associated with in-hospital mortality due to acute myocardial infarction (AMI). We evaluated a stratified random sample of 391 medical records (out of 1,936 hospital admissions forms) with AMI as the primary diagnosis in the city of Rio de Janeiro. Factors associated with in-hospital death were studied through logistic modeling. Models were developed directly from the SIH and from medical records. ROC curves were constructed to allow comparison of the different models. We found an AMI diagnostic confirmation = 91.7% and hospital mortality = 20.6%. The logistic model derived from medical records produced the best fit (concordance = 90.1%). Although the SIH model had a worse fit (concordance = 70.6%), the correction of keying-in and information errors using data from medical records did not significantly modify its performance. Under-recording of secondary diagnosis was high in the SIH forms and was the main limiting factor. 相似文献