全文获取类型
收费全文 | 3111篇 |
免费 | 280篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 7篇 |
儿科学 | 69篇 |
妇产科学 | 80篇 |
基础医学 | 397篇 |
口腔科学 | 89篇 |
临床医学 | 255篇 |
内科学 | 565篇 |
皮肤病学 | 60篇 |
神经病学 | 385篇 |
特种医学 | 100篇 |
外科学 | 429篇 |
综合类 | 66篇 |
一般理论 | 6篇 |
预防医学 | 375篇 |
眼科学 | 50篇 |
药学 | 283篇 |
中国医学 | 3篇 |
肿瘤学 | 180篇 |
出版年
2023年 | 26篇 |
2022年 | 21篇 |
2021年 | 66篇 |
2020年 | 40篇 |
2019年 | 51篇 |
2018年 | 74篇 |
2017年 | 60篇 |
2016年 | 56篇 |
2015年 | 51篇 |
2014年 | 77篇 |
2013年 | 106篇 |
2012年 | 254篇 |
2011年 | 221篇 |
2010年 | 123篇 |
2009年 | 113篇 |
2008年 | 177篇 |
2007年 | 192篇 |
2006年 | 219篇 |
2005年 | 198篇 |
2004年 | 198篇 |
2003年 | 175篇 |
2002年 | 161篇 |
2001年 | 54篇 |
2000年 | 38篇 |
1999年 | 42篇 |
1998年 | 40篇 |
1997年 | 27篇 |
1996年 | 29篇 |
1995年 | 20篇 |
1994年 | 17篇 |
1993年 | 22篇 |
1992年 | 25篇 |
1991年 | 24篇 |
1990年 | 15篇 |
1989年 | 19篇 |
1988年 | 15篇 |
1987年 | 26篇 |
1986年 | 23篇 |
1985年 | 16篇 |
1984年 | 20篇 |
1983年 | 16篇 |
1982年 | 18篇 |
1980年 | 11篇 |
1979年 | 18篇 |
1978年 | 18篇 |
1977年 | 13篇 |
1976年 | 20篇 |
1975年 | 19篇 |
1974年 | 12篇 |
1973年 | 14篇 |
排序方式: 共有3399条查询结果,搜索用时 15 毫秒
71.
72.
Dimitrios Adamis Vicky Papanikolaou Michael Michailidis Alastair J.D. Macdonald 《Aging & mental health》2013,17(2):258-264
Objectives: There is a growing need for evaluation of the results of mental health services and clinical treatment in older people, but evidence for effectiveness is limited in Greece. The Health of the Nations Outcome Scales for Elderly People (HoNOS65+) are promising instruments for the assessment of mental, physical and social health in older persons. They have been translated into the Greek language but have not been validated. The aim was to assess the inter-rater reliability, intraclass correlation, concurrent validity, internal consistency and sensitivity to change of HoNOS65+ in a Greek sample of older people with mental health problems. Method: Two samples, one of inpatients in a psychiatric hospital and the other of older people living in the community were used. In order to test the extent to which the HoNOS65+ were sensitive to change the first sample was reassessed after two months and the second after three months. For each participant HoNOS65+ were completed by two independent raters, and the clinician rated blindly each participant on the Stockton Geriatric Rating Scale and a scale which measured behavioural, physical, cognitive and emotional status. Results: In both groups (inpatients n?=?50, community n?=?65), the inter-rater reliability, intraclass correlation and concurrent validity were high while internal consistency of the scales taken together was low. At reassessment in 98 participants, HoNOS65+ showed changes comparable to clinician ratings. Conclusion: The Greek version of HoNOS65+ can achieve high levels of reliability, validity and sensitivity to change for measuring outcomes in older people with mental health problems. 相似文献
73.
Chad E. Eckert Rong Fan Brandon Mikulis Mathew Barron Christopher A. Carruthers Vincent M. Friebe Naren R. Vyavahare Michael S. Sacks 《Acta biomaterialia》2013,9(1):4653-4660
While the role of collagen and elastin fibrous components in heart valve valvular biomechanics has been extensively investigated, the biomechanical role of the glycosaminoglycan (GAG) gelatinous-like material phase remains unclear. In the present study, we investigated the biomechanical role of GAGs in porcine aortic valve (AV) leaflets under tension utilizing enzymatic removal. Tissue specimens were removed from the belly region of porcine AVs and subsequently treated with either an enzyme solution for GAG removal or a control (buffer with no enzyme) solution. A dual stress level test methodology was used to determine the effects at low and high (physiological) stress levels. In addition, planar biaxial tests were conducted both on-axis (i.e. aligned to the circumferential and radial axes) and at 45° off-axis to induce maximum shear, to explore the effects of augmented fiber rotations on the fiber–fiber interactions. Changes in hysteresis were used as the primary metric of GAG functional assessment. A simulation of the low-force experimental setup was also conducted to clarify the internal stress system and provide viscoelastic model parameters for this loading range. Results indicated that under planar tension the removal of GAGs had no measureable affect extensional mechanical properties (either on- or 45° off-axis), including peak stretch, hysteresis and creep. Interestingly, in the low-force range, hysteresis was markedly reduced, from 35.96 ± 2.65% in control group to 25.00 ± 1.64% (p < 0.001) as a result of GAG removal. Collectively, these results suggest that GAGs do not play a direct role in modulating the time-dependent tensile properties of valvular tissues. Rather, they appear to be strongly connected with fiber–fiber and fiber–matrix interactions at low force levels. Thus, we speculate that GAGs may be important in providing a damping mechanism to reduce leaflet flutter when the leaflet is not under high tensile stress. 相似文献
74.
Croft AP Situnayake D Khair O Giovanni G Carruthers D Sivaguru A Gordon C 《Clinical rheumatology》2012,31(6):1013-1018
Chronic progressive multisystem granulomatous disease is seen in 10-30% of patients with sarcoidosis and can result in end organ damage. Corticosteroids are the mainstay of treatment with the addition of cytotoxic agents in severe cases. Some patients are refractory to such treatment and, therefore, management is a challenge. There is currently limited evidence for biological agents such as infliximab, a monoclonal anti-tumor necrosis factor-α antibody in the treatment of multisystem sarcoidosis. We report outcomes of three patients with extensive multisystem sarcoidosis refractory to conventional treatment and treated at our center. Clinical assessment and radiographic imaging were used to assess the response to infliximab treatment. Infliximab therapy induced clinical remission in all three patients, and this clinical response correlated with radiographic evidence of the resolution of granulomatous disease. Serum ACE level was reduced in all cases, and daily steroid dosage was reduced. We propose that infliximab can be an effective treatment in patients with multisystem complex sarcoidosis refractory to conventional drug therapy and can result in sustained clinical remission. Our experience supports the urgent need for randomized controlled clinical trials of anti-TNF therapy in refractory systemic sarcoidosis. 相似文献
75.
76.
McAllister DA Maclay JD Mills NL Leitch A Reid P Carruthers R O'Connor J McAlpine L Chalmers G Newby DE Clark E Macfarlane PW Macnee W 《The European respiratory journal》2012,39(5):1097-1103
Cardiovascular disease is common in chronic obstructive pulmonary disease (COPD) and raised troponin is common in exacerbations. However, the prevalence of myocardial infarction following hospitalisation for exacerbation of COPD is unknown. Patients aged ≥ 40 yrs hospitalised with acute exacerbation of COPD (n = 242) with ≥ 10 pack-yrs of cigarette smoking were included in a prospective case series conducted in four hospitals. Patients whose primary presenting complaint was chest pain or who had an alternative diagnosis were excluded. Chest pain histories, serial ECGs and troponin levels were obtained. The mean ± SD age was 69 ± 9 yrs; 108 (45%) patients were male and almost half were current smokers. 124 (51%; 95% CI 48-58%) patients had chest pain, which was exertional in 62 (26%). 24 (10%) had raised troponin, among whom, 20 (8.3%; 95% CI 5.1-12.5%) had chest pain and/or serial ECG changes, fulfilling the 2007 Universal Definition of Myocardial Infarction. Neither chest pain (p = 0.77) nor serial ECG changes (p = 0.39) were associated with raised troponin. Raised troponin, chest pain and serial ECG changes are common in patients admitted to hospital with exacerbation of COPD. Overall, one in 12 patients met the criteria for myocardial infarction. Whether these patients would benefit from further cardiac investigation is unknown. 相似文献
77.
78.
Chris Westgarth-Taylor Leonnie de Lijster Guido van Bogerijen Alastair J. W. Millar Jonathan Karpelowsky 《Surgical endoscopy》2013,27(10):3696-3704
Background
This study was designed to determine whether a decrease in renal oxygenation occurs during CO2 pneumoperitoneum in children with normal renal function undergoing laparoscopy.Methods
Near infrared spectroscopy (NIRS) probes were applied to both the lateral flank (T10-L2) and lateral cerebral area of all patients with normal renal function undergoing a laparoscopic procedure. Information was recorded in 5-s intervals for 15-min before, during, and for 15-min after pneumoperitoneum insufflation and desufflation. Simultaneously, additional hemodynamic parameters (arterial saturation, mean arterial pressure, end tidal CO2, and urine output) were recorded every 5-min. Pneumoperitoneum pressures used were: 0–1 month old, <6 mmHg; 2–12 months old, <8 mmHg; 1–2 years old, <10 mmHg, and 2–8 years old, <12 mmHg. The lowest possible pressure was used to obtain adequate vision.Results
Twenty-nine patients were enrolled in the study. Renal regional oxygen saturation (rSO2) did not decrease significantly between baseline (preinsufflation), insufflation, and desufflation of the pneumoperitoneum (p = 0.343). Meta-analysis of this data demonstrated a pooled weighted difference of ?1.4 (?3.5 to 0.54), confirming no significant change. A significant increase in cerebral rSO2 occurred during the insufflation period of the CO2 pneumoperitoneum (p = 0.001). Heart rate (F = 11.05; p < 0.001) and mean arterial pressure (MAP) (F = 19.2; p < 0.001) also increased significantly during the laparoscopy. No significant correlation was identified between fluid input and urine output during the laparoscopy (r = 0.012; p = 0.953).Conclusions
Renal hypoxia does not occur during laparoscopic surgery in children if the minimum age-appropriate intra-abdominal pressures are used. Alternative causes must account for the oliguria and anuria demonstrated in children undergoing laparoscopy. 相似文献79.
Functional recovery from injuries to the brain or spinal cord represents a major clinical challenge. The transplantation of stem cells, traditionally isolated from embryonic tissue, may help to reduce damage following such events and promote regeneration and repair through both direct cell replacement and neurotrophic mechanisms. However, the therapeutic potential of using embryonic stem/progenitor cells is significantly restricted by the availability of embryonic tissues and associated ethical issues. Populations of stem cells reside within the dental pulp, representing an alternative source of cells that can be isolated with minimal invasiveness, and thus should illicit fewer moral objections, as a replacement for embryonic/fetal‐derived stem cells. Here we discuss the similarities between dental pulp stem cells (DPSCs) and the endogenous stem cells of the central nervous system (CNS) and their ability to differentiate into neuronal cell types. We also consider in vitro and in vivo studies demonstrating the ability of DPSCs to help protect against and repair neuronal damage, suggesting that dental pulp may provide a viable alternative source of stem cells for replacement therapy following CNS damage. © 2013 Wiley Periodicals, Inc. 相似文献
80.
Dr Dimitrios Adamis Barbara C. Van Munster Alastair J. D. Macdonald 《International review of psychiatry (Abingdon, England)》2013,25(1):20-29
Delirium not induced by alcohol or other psychoactive substance and alcohol withdrawal delirium (or delirium tremens) are both cerebral syndromes with similar presentations and are associated with various adverse outcomes. Recently, interest in identifying genetic predisposing factors that influence the occurrence or the outcome of delirium has become a prominent point of delirium research. We systematically searched published articles concerning genetic associations and the occurrence and outcome of delirium. Of 33 identified articles, six investigated non-alcohol withdrawal delirium, and from those six, five evaluated an association with apolipoprotein E (APOE). One association of APOE genotype with the emergence of delirium and two associations of APOE genotype with the duration of delirium were reported. The remaining 27 identified articles investigated genetic associations with alcohol withdrawal delirium and were mainly related to dopamine. Two studies reported a significant association of alcohol withdrawal delirium with the dopamine transporter gene (SLC6A3) and the dopamine receptor 3 (DRD3). Results are inconclusive, and no hard evidence exists due primarily to insufficiently powered studies and other methodological issues. Prospective studies incorporating systematic and rigorous diagnostic criteria and involving long term follow up are needed to advance understanding of this field. 相似文献