全文获取类型
收费全文 | 702篇 |
免费 | 37篇 |
国内免费 | 46篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 50篇 |
妇产科学 | 20篇 |
基础医学 | 68篇 |
口腔科学 | 38篇 |
临床医学 | 102篇 |
内科学 | 173篇 |
皮肤病学 | 10篇 |
神经病学 | 19篇 |
特种医学 | 118篇 |
外科学 | 61篇 |
综合类 | 10篇 |
预防医学 | 24篇 |
眼科学 | 3篇 |
药学 | 54篇 |
1篇 | |
肿瘤学 | 32篇 |
出版年
2023年 | 5篇 |
2022年 | 7篇 |
2021年 | 10篇 |
2019年 | 7篇 |
2018年 | 14篇 |
2017年 | 11篇 |
2016年 | 12篇 |
2015年 | 18篇 |
2014年 | 28篇 |
2013年 | 31篇 |
2012年 | 17篇 |
2011年 | 14篇 |
2010年 | 22篇 |
2009年 | 26篇 |
2008年 | 10篇 |
2007年 | 43篇 |
2006年 | 17篇 |
2005年 | 12篇 |
2004年 | 8篇 |
2003年 | 6篇 |
2002年 | 11篇 |
2001年 | 4篇 |
2000年 | 8篇 |
1999年 | 12篇 |
1998年 | 44篇 |
1997年 | 52篇 |
1996年 | 54篇 |
1995年 | 45篇 |
1994年 | 30篇 |
1993年 | 30篇 |
1992年 | 2篇 |
1991年 | 12篇 |
1990年 | 8篇 |
1989年 | 15篇 |
1988年 | 24篇 |
1987年 | 20篇 |
1986年 | 14篇 |
1985年 | 14篇 |
1984年 | 7篇 |
1983年 | 8篇 |
1982年 | 9篇 |
1981年 | 8篇 |
1980年 | 11篇 |
1978年 | 4篇 |
1977年 | 8篇 |
1976年 | 2篇 |
1975年 | 5篇 |
1973年 | 1篇 |
1967年 | 1篇 |
1960年 | 1篇 |
排序方式: 共有785条查询结果,搜索用时 15 毫秒
71.
72.
Kersten MJ; Evers LM; Dellemijn PL; van den Berg H; Portegies P; Hintzen RQ; van Lier RA; von dem Borne AE; van Oers RH 《Blood》1996,87(5):1985-1989
Diagnosis of meningeal localization of lymphoid malignancies by means of cytologic examination of the cerebrospinal fluid (CSF) can be difficult. Thus far no reliable CSF tumor markers have been identified. CD27 is a transmembrane disulfide-linked 55-kD homodimer present on most peripheral blood T cells and on a subset of B cells. CD27 is also expressed on human malignant B cells and high levels of soluble CD27 can be present in the serum of patients with B-cell malignancies. The aim of this study is to determine prospectively the diagnostic value of CSF sCD27 as a tumor marker in patients with meningeal localization of lymphoid malignancies. CSF sCD27 levels were determined by sandwich enzyme-linked immunosorbent assay. The optimal cut-off value using receiver operator characteristics curves was found to be 10 U/mL. sCD27 levels were normal in all 50 control patients (lumbar disc protrusion) and in 39 of 40 samples obtained from patients with either solid tumors or acute myeloid leukemia. Of 104 CSF samples from 70 children with acute lymphoblastic leukemia (ALL) or non-Hodgkin's lymphoma (NHL) undergoing routine central nervous system (CNS) staging, sCD27 was false positive and false negative in only one sample each. In 70 samples from 45 patients suspected of meningeal localization of ALL or NHL, the sCD27 test had an excellent sensitivity (100%) and specificity (82%). In 7 patients with positive CSF studied longitudinally, sCD27 levels correlated very well with remission and relapse. sCD27 levels were not nonspecifically increased by the administration of cytostatic drugs. Finally, sCD27 was also elevated in the 4 patients studied with primary central nervous system lymphoma (PCNSL). CSF sCD27 is a promising tumor marker in patients with either meningeal localization of lymphoid malignancies or PCNSL, and can be useful in the differential diagnosis of CNS involvement by either lymphoid malignancies or solid tumors. 相似文献
73.
Kei Masani Milad Alizadeh-Meghrazi Dimitry G. Sayenko Jose Zariffa Cameron Moore Lora Giangregorio Milos R. Popovic B. Catharine Craven 《The journal of spinal cord medicine》2014,37(5):575-581
Objective
To investigate the effects of intermittent passive standing (PS) and whole body vibration (WBV) on the electromyography (EMG) activity, cross-sectional area, and density of lower extremity muscles in individuals with chronic motor complete spinal cord injury (SCI).Design
Case series.Methods
Seven adult men with chronic (≥2 years), thoracic motor complete (AIS A–B) SCI completed a 40-week course of thrice-weekly intermittent PS-WBV therapy, in a flexed knee posture (160°), for 45 minutes per session at a frequency of 45 Hz and 0.6–0.7 mm displacement using the WAVE® Pro Plate, with an integrated EasyStand™ standing frame. EMG was measured in major lower extremity muscles to represent muscle activity during PS-WBV. The cross-sectional area and density of the calf muscles were measured using peripheral quantitative computed tomography at the widest calf cross-section (66% of the tibia length) at pre- and post-intervention. All measured variables were compared between the pre- and post-intervention measurements to assess change after the PS-WBV intervention.Results
PS-WBV acutely induced EMG activity in lower extremity muscles of SCI subjects. No significant changes in lower extremity EMG activity, muscle cross-sectional area, or density were observed following the 40-week intervention.Conclusions
Although acute exposure to PS-WBV can induce electrophysiological activity of lower extremity muscles during PS in men with motor complete SCI, the PS-WBV intervention for 40 weeks was not sufficient to result in enhanced muscle activity, or to increase calf muscle cross-sectional area or density. 相似文献74.
Caitlin McArthur George Ioannidis Micaela Jantzi Loretta Hillier Jonathan D. Adachi Lora Giangregorio John Hirdes Alexandra Papaioannou 《Journal of the American Medical Directors Association》2021,22(5):1035-1042
ObjectivesThe purpose of our study was to identify factors that predict 1-year incident hip and major osteoporotic non-hip fractures (ie, wrist, spine, pelvis, humerus) for home care recipients while accounting for the competing risk of death.DesignWe conducted a retrospective cohort study with linked population data.Setting and ParticipantsAll home care recipients in Ontario, Canada, receiving services for more than 6 months with an admission assessment between April 1, 2011, and March 31, 2015, were included.MethodsClinical data from the Resident Assessment Instrument Home Care were linked to fracture data from the Discharge Abstract Database and the National Acute Care Reporting System. Competing risk proportional hazard regressions using the Fine and Grey method were performed to model the association between potential risk factors and fracture.ResultsPrevious fall, previous fracture, cognitive impairment, unsteady gait, alcohol use, tobacco use, and Parkinson disease were consistently associated with all fracture types. Cognitive impairment (hazard ratio 2.09; 95% confidence interval 1.86–2.36) and wandering [1.66 (1.06–1.27)] were most predictive of hip fractures and being female [1.86 (1.76–1.98)] and experiencing a previous fracture [1.86 (1.76–1.98)] were most predictive of non-hip fractures. Risk factors unique to non-hip fractures as compared with hip fractures were locomotion ability outdoors and psychotropic medication use.Conclusions and ImplicationsOur results indicate that, in addition to typical fracture risk factors, home care recipients have unique characteristics that increase their risk. Fracture risk assessment tools and subsequent prevention strategies should be modified to accurately identify home care recipients at risk for imminent 1-year fracture. 相似文献
75.
María Clara Restrepo-Méndez Aluísio JD Barros Kerry LM Wong Hope L Johnson George Pariyo Giovanny VA Fran?a Fernando C Wehrmeister Cesar G Victora 《Bulletin of the World Health Organization》2016,94(11):794-805B
ObjectiveTo investigate disparities in full immunization coverage across and within 86 low- and middle-income countries.MethodsIn May 2015, using data from the most recent Demographic and Health Surveys and Multiple Indicator Cluster Surveys, we investigated inequalities in full immunization coverage – i.e. one dose of bacille Calmette-Guérin vaccine, one dose of measles vaccine, three doses of vaccine against diphtheria, pertussis and tetanus and three doses of polio vaccine – in 86 low- or middle-income countries. We then investigated temporal trends in the level and inequality of such coverage in eight of the countries.FindingsIn each of the World Health Organization’s regions, it appeared that about 56–69% of eligible children in the low- and middle-income countries had received full immunization. However, within each region, the mean recorded level of such coverage varied greatly. In the African Region, for example, it varied from 11.4% in Chad to 90.3% in Rwanda. We detected pro-rich inequality in such coverage in 45 of the 83 countries for which the relevant data were available and pro-urban inequality in 35 of the 86 study countries. Among the countries in which we investigated coverage trends, Madagascar and Mozambique appeared to have made the greatest progress in improving levels of full immunization coverage over the last two decades, particularly among the poorest quintiles of their populations.ConclusionMost low- and middle-income countries are affected by pro-rich and pro-urban inequalities in full immunization coverage that are not apparent when only national mean values of such coverage are reported. 相似文献
76.
77.
78.
B De Vizia A Mansi A Giangregorio R Troncone 《Acta paediatrica (Oslo, Norway : 1992)》1995,84(1):103-105
A 7-month-old boy on an oligoantigenic diet because of multiple food intolerances presented with anorexia, failure to gain weight and severe hypochloremic metabolic alkalosis with hyperreninemia. Clinical symptoms and biochemical abnormalities disappeared after adequate dietary supplementation with potassium and sodium chloride. This case emphasizes that minimal daily mineral requirements must be provided in infant diets, and highlights the risk of nutritional deficiencies inherent in the prolonged use of oligoantigenic diets not adequately supplemented. 相似文献
79.
80.
LM Paes da Silva Ramos Fernandes R Ordinola-Zapata MA Húngaro Duarte AL Alvares Capelozza 《Dento maxillo facial radiology》2013,42(1):80179163