全文获取类型
收费全文 | 4430篇 |
免费 | 276篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 78篇 |
儿科学 | 87篇 |
妇产科学 | 131篇 |
基础医学 | 585篇 |
口腔科学 | 39篇 |
临床医学 | 444篇 |
内科学 | 808篇 |
皮肤病学 | 60篇 |
神经病学 | 354篇 |
特种医学 | 186篇 |
外科学 | 684篇 |
综合类 | 69篇 |
一般理论 | 2篇 |
预防医学 | 377篇 |
眼科学 | 202篇 |
药学 | 334篇 |
中国医学 | 8篇 |
肿瘤学 | 263篇 |
出版年
2023年 | 35篇 |
2022年 | 43篇 |
2021年 | 103篇 |
2020年 | 50篇 |
2019年 | 98篇 |
2018年 | 97篇 |
2017年 | 73篇 |
2016年 | 84篇 |
2015年 | 99篇 |
2014年 | 117篇 |
2013年 | 206篇 |
2012年 | 256篇 |
2011年 | 268篇 |
2010年 | 200篇 |
2009年 | 158篇 |
2008年 | 254篇 |
2007年 | 248篇 |
2006年 | 227篇 |
2005年 | 226篇 |
2004年 | 200篇 |
2003年 | 170篇 |
2002年 | 200篇 |
2001年 | 72篇 |
2000年 | 92篇 |
1999年 | 84篇 |
1998年 | 46篇 |
1997年 | 29篇 |
1996年 | 34篇 |
1995年 | 24篇 |
1994年 | 37篇 |
1993年 | 26篇 |
1992年 | 66篇 |
1991年 | 71篇 |
1990年 | 59篇 |
1989年 | 56篇 |
1988年 | 65篇 |
1987年 | 67篇 |
1986年 | 34篇 |
1985年 | 38篇 |
1984年 | 32篇 |
1983年 | 20篇 |
1982年 | 33篇 |
1981年 | 19篇 |
1980年 | 23篇 |
1979年 | 28篇 |
1978年 | 20篇 |
1977年 | 18篇 |
1976年 | 19篇 |
1974年 | 16篇 |
1971年 | 14篇 |
排序方式: 共有4711条查询结果,搜索用时 33 毫秒
101.
102.
Steven L. Baumann William Jacobowitz Donna Tanzi Tricia A. Lewis Margaret J. Krepp Eileen Levy 《Issues in mental health nursing》2018,39(5):439-444
ABSTRACTThis retrospective study sought to investigate issues related to the safety of psychopharmacological agents used by acutely medically ill hospitalized older adults. It explored if there were any associations between commonly prescribed psychiatric medications that medically ill hospitalized older adults received and adverse events. It also sought to compare the safety of antidepressants, sedative/hypnotics, and antipsychotics, when used as a standing (on a preset schedule) and as needed pro re nata (PRN) basis. The study found that psychopharmacological agents are frequently prescribed for medically ill hospitalized older adults. No statistically significant difference was found as far as safety was concerned. The number of PRN medications that were used, and the total number of medications was associated with increased risk of transfer within the hospital to a higher level of care or transfer upon discharge to long-term-care/rehabilitation or hospice. Overall, the use of psychopharmacological agents did not appear to be related to serious adverse events. 相似文献
103.
104.
Jennifer Barber Tricia M McKeever Sarah E McDowell Jennifer A Clayton Robin E Ferner Richard D Gordon Michael Stowasser Kevin M O'Shaughnessy Ian P Hall Mark Glover 《British journal of clinical pharmacology》2015,79(4):566-577
AIMS
Hyponatraemia is one of the major adverse effects of thiazide and thiazide-like diuretics and the leading cause of drug-induced hyponatraemia requiring hospital admission. We sought to review and analyze all published cases of this important condition.METHODS
Ovid Medline, Embase, Web of Science and PubMed electronic databases were searched to identify all relevant articles published before October 2013. A proportions meta-analysis was undertaken.RESULTS
One hundred and two articles were identified of which 49 were single patient case reports. Meta-analysis showed that mean age was 75 (95% CI 73, 77) years, 79% were women (95% CI 74, 82) and mean body mass index was 25 (95% CI 20, 30) kg m−2. Presentation with thiazide-induced hyponatraemia occurred a mean of 19 (95% CI 8, 30) days after starting treatment, with mean trough serum sodium concentration of 116 (95% CI 113, 120) mm and serum potassium of 3.3 (95% CI 3.0, 3.5) mm. Mean urinary sodium concentration was 64 mm (95% CI 47, 81). The most frequently reported drugs were hydrochlorothiazide, indapamide and bendroflumethiazide.CONCLUSIONS
Patients with thiazide-induced hyponatraemia were characterized by advanced age, female gender, inappropriate saliuresis and mild hypokalaemia. Low BMI was not found to be a significant risk factor, despite previous suggestions. The time from thiazide initiation to presentation with hyponatraemia suggests that the recommended practice of performing a single investigation of serum biochemistry 7–14 days after thiazide initiation may be insufficient or suboptimal. Further larger and more systematic studies of thiazide-induced hyponatraemia are required. 相似文献105.
van Veen TA van Rijen HV Wiegerinck RF Opthof T Colbert MC Clement S de Bakker JM Jongsma HJ 《Journal of molecular and cellular cardiology》2002,34(10):1411-1423
BACKGROUND: Beta-MHC-hRARalpha transgenic mice express a constitutively active (truncated) form of the human retinoic acid receptor which triggers development of dilated cardiomyopathy. In those hearts, we studied expression of gap junction proteins in relation to electrical impulse propagation. METHODS AND RESULTS: As compared to wildtype mice, hearts of 4-6 month old mice with 7-12 inserted hRARalpha copies are marked by an increased heart weight/body weight- and heart weight/tibia length ratio. 3-extremity lead ECGs revealed prolongation of the Q-j interval suggesting delayed ventricular activation. Mapping of electrical activity of epi- and endocardial left ventricular free wall revealed activation delay, increased heterogeneity in conduction and regional conduction block. Ventricular tachycardias did not occur spontaneously nor could be induced by ventricular pacing. Immunohistochemical analysis showed profound and heterogeneous redistribution and down-regulation of the gap junction protein connexin43 (Cx43) in the left ventricular free wall. Here, hRARalpha expression induced re-expression of the hypertrophic markers alpha-skeletal actin and beta-MHC, and in 3 out of 10 severely affected mice, re-expression of Cx40. Concomitant with changes in expression/distribution of Cx43, changes in expression and distribution of beta-catenin and N-cadherin (two other intercalated disk associated proteins) were observed. CONCLUSIONS: Beta-MHC-hRARalpha transgenic hearts show heterogeneous re-expression of (early) sarcomeric genes while expression of connexin43, N-cadherin and beta-catenin is down-regulated. We postulate that the resulting aberrant ventricular activation does not trigger development of lethal arrhythmias due to the small size of remaining healthy ventricular tissue where the transgene is not expressed. 相似文献
106.
STUDY OBJECTIVES: Following the development of the Caribbean Guidelines for Asthma Care, we examined the utilization of inhaled medications in asthmatic patients in Trinidad, West Indies. SETTING: Chest Clinic, Ministry of Health, Trinidad. PARTICIPANTS: Physician-diagnosed asthmatic patients who attended the Chest Clinic between July 1998 and August 2000. MEASUREMENTS AND RESULTS: A consecutive sample of patients who were > 7 years of age (n = 402) was interviewed about compliance with, understanding of, and use of inhaler medication. The inhaler technique of these patients was directly observed. Inhaled steroid therapy was prescribed in 83% of patients but were prescribed the least in elderly patients (63%) and children (62%). Salbutamol was prescribed in 98% of patients, and ipratropium and sodium cromoglycate were selectively prescribed in elderly men and children, respectively. Only 33% of patients used the inhaler correctly, and children and the elderly were the least efficient in its use. The use of a spacer device was advised in 19% of patients, including only 6% of the elderly patients. Explanations for different inhaler therapies were given to 62% of patients, and 53% of patients could describe these reasons. The reported 40% noncompliance rate among patients in the sample was primarily a result of long waiting periods at the pharmacy (58%) and the personal cost incurred on purchasing the medication (52%). CONCLUSIONS: Educating patients, with a focus on children and the elderly, in inhaler techniques and reinforcing understanding of asthma medications can improve asthma management in Trinidad. Asthma caregivers in the Caribbean should ensure the appropriate dissemination of the guidelines and should outline strategies for their implementation. 相似文献
107.
De Sutter J Van de Wiele C Gheeraert P De Buyzere M Gevaert S Taeymans Y Dierckx R De Backer G Clement D 《The American journal of cardiology》1999,83(2):255-7, A5
In patients treated successfully with primary angioplasty for a first myocardial infarction, the Selvester 32-point score correlates well with infarct size measured with quantitative thallium-201 perfusion imaging. Therefore, it is a useful parameter for infarct sizing, particularly in patients with anterior infarction or reduced ejection fraction at discharge. 相似文献
108.
R. Goldschmeding C. M. van Dalen N. Faber J. Calafat T. W. J. Huizinga C. E. van der Schoot L. T. Clement A. E. G. Kr. von dem Borne 《British journal of haematology》1992,81(3):336-345
The human neutrophil-specific alloantigen NB1 was identified as a glycosyl-phosphatidylinositol (GPI)-anchored N-glycosylated protein of M(r) 56-62 kD under reducing conditions. Under non-reducing conditions its M(r) was 49-55 kD. This glycoprotein antigen was found to be expressed by only a subpopulation of normal donor neutrophils, and could not be detected on other blood cells. The allotypic epitope recognized by human anti-NB1 IgG was also recognized by the mouse monoclonal antibody 1B5. The percentage of neutrophils stained by these antibodies varied greatly among healthy donors (range 0-100%). When 16 donors were repeatedly tested, the NB1-positive neutrophil fraction appeared to remain remarkably constant over time in most donors, but significant fluctuations were seen in some. NB1 antigen was found to be expressed not only on the plasma membrane, but also intracellularly on the membranes of small vesicles and specific granules. The neutrophils which expressed NB1 antigen on the plasma membrane were the same as those with intracellular expression of this antigen. Crosslinking of NB1 antigen on the plasma membrane with monoclonal antibody 1B5 and goat-anti-mouse Ig resulted in internalization of the complex, while in-vitro stimulation of neutrophils caused an increase of the intensity of plasma membrane staining with anti-NB1, but only of those cells that were positive already prior to stimulation. The NB1 glycoprotein thus appears to identify a distinct subset of neutrophils, the size of which greatly varies among healthy donors. The function of the NB1 glycoprotein remains unclear, but its behaviour upon crosslinking and chemotactic peptide stimulation suggests a possible role as receptor molecule. 相似文献
109.
LeVan TD Von Essen S Romberger DJ Lambert GP Martinez FD Vasquez MM Merchant JA 《American journal of respiratory and critical care medicine》2005,171(7):773-779
RATIONALE AND OBJECTIVES: Farmers experience airway obstruction, which may be attributable in part to endotoxin inhalation. CD14 is a receptor for endotoxin. MATERIALS AND METHODS: Based on our findings of increased circulating CD14 associated with the CD14/-159 T allele, we hypothesized that carriers of this allele would have decreased lung function among endotoxin-exposed individuals. CD14/-159TT farmers (n = 19) had significantly lower lung function as measured by FEV1 (p = 0.028) and mean forced expiratory flow during the middle half of the FVC (FEF25-75) (p = 0.05) compared with farmers with the C allele (n = 78). Also, farmers with the CD14/-1619GG genotype (n =11) were associated with lower lung function (FEV1, p = 0.008; FEF25-75, p = 0.009) compared with farmers with the A allele (n = 86). RESULTS: No association between CD14/-550 and lung function was observed (FEV1, p = 0.32; FEF25-75, p = 0.11). Increased prevalence of wheezing was reported in farmers homozygous for CD14/-159T (p = 0.013) or CD14/-1619G (p = 0.019) compared with farmers with the CC or AA genotype, respectively. No association was found between TLR4/Asp299Gly and lung function or wheeze. CONCLUSION: We conclude that the CD14/-159 or CD14/-1619 loci may play a role in modulating lung function and wheeze among agricultural workers. 相似文献
110.