全文获取类型
收费全文 | 3071篇 |
免费 | 224篇 |
国内免费 | 14篇 |
专业分类
耳鼻咽喉 | 15篇 |
儿科学 | 114篇 |
妇产科学 | 161篇 |
基础医学 | 424篇 |
口腔科学 | 54篇 |
临床医学 | 274篇 |
内科学 | 537篇 |
皮肤病学 | 53篇 |
神经病学 | 196篇 |
特种医学 | 506篇 |
外科学 | 422篇 |
综合类 | 83篇 |
一般理论 | 7篇 |
预防医学 | 183篇 |
眼科学 | 64篇 |
药学 | 107篇 |
1篇 | |
肿瘤学 | 108篇 |
出版年
2021年 | 43篇 |
2020年 | 24篇 |
2019年 | 26篇 |
2018年 | 40篇 |
2017年 | 37篇 |
2016年 | 49篇 |
2015年 | 45篇 |
2014年 | 82篇 |
2013年 | 77篇 |
2012年 | 115篇 |
2011年 | 127篇 |
2010年 | 95篇 |
2009年 | 94篇 |
2008年 | 96篇 |
2007年 | 122篇 |
2006年 | 109篇 |
2005年 | 90篇 |
2004年 | 85篇 |
2003年 | 83篇 |
2002年 | 66篇 |
2001年 | 75篇 |
2000年 | 59篇 |
1999年 | 63篇 |
1998年 | 103篇 |
1997年 | 100篇 |
1996年 | 108篇 |
1995年 | 84篇 |
1994年 | 60篇 |
1993年 | 68篇 |
1992年 | 41篇 |
1991年 | 53篇 |
1990年 | 49篇 |
1989年 | 84篇 |
1988年 | 66篇 |
1987年 | 65篇 |
1986年 | 80篇 |
1985年 | 90篇 |
1984年 | 59篇 |
1983年 | 52篇 |
1982年 | 34篇 |
1981年 | 42篇 |
1980年 | 44篇 |
1979年 | 14篇 |
1978年 | 34篇 |
1977年 | 37篇 |
1976年 | 38篇 |
1975年 | 39篇 |
1974年 | 16篇 |
1971年 | 14篇 |
1967年 | 13篇 |
排序方式: 共有3309条查询结果,搜索用时 15 毫秒
1.
Isolated patellofemoral arthritis is an increasingly recognized entity, and is usually associated with previous patellofemoral dysplasia or instability. Patellofemoral arthroplasty (PFA) has evolved significantly in recent years, both in terms of implant design and importantly in the understanding of appropriate patient selection. This review outlines the indications and investigations for PFA, provides a brief history of the development of contemporary implants, and presents the clinical outcomes for the prostheses most commonly used in the UK. In addition, it provides a detailed surgical technique for implantation of an onlay implant, with tips on how to optimize patellofemoral biomechanics and thus achieve a consistently good outcome. 相似文献
2.
Thomas J. Cahill Shehan Hettiaratchy Alex Clarke Peter E.M. Butler 《Transplantation reviews (Orlando, Fla.)》2006,20(2):76-81
Animal models have traditionally provided the basis for preliminary investigation of new techniques prior to trials taking place in human subjects. The timing of when to proceed with human trials is difficult, as the accuracy of preclinical models can only be determined with hindsight. This review outlines the progression from transplantation in animal models to man. Now that many transplant procedures are well established, it is possible to assess the predictive value and limitations of animal models. These results are of great importance in the current debate about composite tissue allotransplantation (CTA) and in particular facial transplantation. This progression of CTA from animal models to man is outlined and compared with early renal, cardiac, and liver transplants. There is some evidence to suggest that animal models may have been misleading in CTA and that this has effectively delayed the transition to humans. The role for animal models in facial transplantation, which is currently making the step to clinical trials, is discussed. 相似文献
3.
The rejection of sponge matrix allografts across H-2 barriers has generally been found to contain specifically sensitized cytotoxic T cells to donor alloantigen. There is one exception: sponge matrix allografts that differ only with respect to class II alloantigens do not contain specifically sensitized cytotoxic T cells. We therefore investigated the capacity of infiltrating cells removed from sponge matrix allografts to generate delayed hypersensitivity reactions after exposure to fresh alloantigen in a footpad assay. Cells infiltrating class I and II allografts were equally capable of eliciting delayed footpad reactions when injected with specific donor alloantigen into the footpads of naive responder strain mice. Allosensitized T-lymphocyte clones of helper or cytotoxic type were also capable of initiating delayed-type hypersensitivity (DTH) reactions in vivo. We conclude that rejecting allografts across class I or II alloantigenic barriers are infiltrated by cells capable of effecting DTH reactions, in addition to their capacity to exert specific helper or specific cytotoxic reactions. The results also support that both helper and cytotoxic T cells can participate in allospecific DTH reactions. 相似文献
4.
Both cyproterone acetate (CPA) and the gonadotrophin-releasing hormone
agonist (GnRHa) have been shown to be effective for the treatment of
hirsutism. We wished to compare the effectiveness of CPA in two standard
doses with GnRHa and add-back therapy and to compare the length of
remission after these treatments. A total of 60 hirsute hyperandrogenic
women was assigned to the following treatment groups: CPA 2 mg with 35
microg of ethinylestradiol for 21 days each month (Diane group), CPA 50 mg,
days 5-15, and ethinylestradiol 50 microg, days 5-25, each month (CPA
group) or Decapeptyl 3.75 mg i.m. every 28 days with the addition of
conjugated oestrogen 0.625 mg, days 1-21, and medroxyprogesterone acetate
10 mg, days 12-21 (GnRHa group). Hirsutism was graded by the
Ferriman-Gallwey-Lorenzo (FGL) index and anagen hair shaft diameters and
serum luteinizing hormone (LH) and testosterone were assessed before and
every 3 months during and after treatment. All women were treated for 1
year with 1 year follow-up. At baseline hirsutism and endocrine patterns
were similar in all groups. After one year of treatment, hirsutism
decreased in all groups but the changes were greater (P <0.05) in the
CPA and GnRHa groups than in the Diane group. Serum LH and testosterone
were lowest in the GnRHa group. After withdrawal, hirsutism increased
rapidly in the Diane and CPA groups and after 6 months, FGL scores and hair
shaft diameters were similar to pretreatment values. In the GnRHa group,
hirsutism increased more gradually and after 1 year of withdrawal, FGL
scores and hair diameters were significantly (P <0.05) less than
pretreatment values. Serum LH and testosterone increased rapidly in all
three groups reaching pretreatment values by 6 months. These data suggest
equal efficacy of the GnRHa and the high dose CPA regimen for the treatment
of hirsutism in hyperandrogenic women. GnRHa with add-back treatment
appears to result in a longer remission of hirsutism in comparison with
CPA.
相似文献
5.
Maxillary sinusitis in adults: an evaluation of placebo-controlled double-blind trials 总被引:1,自引:0,他引:1
BACKGROUND: In general practice, acute sinusitis is frequently diagnosed
and treated with antibiotics. OBJECTIVE: This study aimed to determine the
evidence for the effectiveness of antibiotic treatment in acute maxillary
sinusitis in adults by assessing the methodological quality of
placebo-controlled double-blind randomized trials. METHOD: An evaluation by
four raters through a 35-item scoring-scale for internal and external
validity of all placebo-controlled double-blind randomized trials on acute
sinusitis found between January 1966 and July 1996. RESULTS: Eighty-five
trials were excluded because they were not placebo-controlled,
double-blind, randomized, or were carried out in patients with chronic
sinusitis or in children. The three remaining trials were performed in
different populations (one in general practice) between 1973 and 1978. Only
one study claimed superiority of antibiotic treatment. Different inclusion
criteria and major outcome measures were used by the authors. The
reliability of major outcome events was reported poorly or not at all and
in two studies outcome measures were clinically inappropriate. The studies
scored 30-62% of the maximum attainable score for internal validity and
10-20% for external validity. CONCLUSION: The effectiveness of antibiotic
treatment in acute maxillary sinusitis in a general practice population is
not based sufficiently on evidence.
相似文献
6.
7.
8.
Catherine M. Cahill Melissa J. Green Rajeev Jairam Gin S. Malhi 《Early intervention in psychiatry》2007,1(2):138-149
Aim: This article reviews research centred around juvenile bipolar disorder with particular reference to diagnostic difficulties. Putative deficits are scrutinized with respect to trait likelihood and the roles of neuropsychology and neuroimaging in enhancing our understanding of juvenile bipolar disorder are discussed. Methods: Search terms including childhood, adolescent, youth and juvenile combined with the terms ‘bipolar disorder’, mania, depression and hypomania were used to identify relevant studies in MEDLINE and PsychLit. Results: Over recent years research into this relatively new disorder has increased phenomenally. Key issues within the field include diagnostic specificity, the heritability of the disorder, the impact of comorbidity and the implications of neuropsychological and neuroimaging findings. Conclusion: Despite concerning controversies in literature the diagnosis of bipolar disorder in children and adolescents as compared with adults, promising future research directions include better neurological characterization of the disorder through the application of findings from clinical populations, neuropsychological and neuroimaging research. 相似文献
9.
S M Kieran R A Cahill I Browne S J Sheehan D Mehigan M C Barry 《European journal of vascular and endovascular surgery》2006,32(3):305-308
INTRODUCTION: Concern about the potential detrimental side-effects of beta-blockade on pulmonary function often dissuades against their perioperative use in patients undergoing major arterial surgery (especially in those with chronic obstructive pulmonary disease (COPD)). In this study we aimed to establish prospectively the clinical relevance of these concerns. METHODS: After ethics committee approval and individual informed consent, the pulmonary function of twenty patients (mean age 68.7 years (range 43-82), 11 males) scheduled to undergo non-emergency major vascular surgery was studied by recording symptoms and spirometry before and after institution of effective beta-blockade. Fifteen patients (75%) had significant smoking histories (mean pack years/patient=50), while 12 (60%) had COPD. RESULTS: All patients tolerated effective beta-blockade satisfactorily without developing either subjective deterioration in symptoms or significant change on spirometry. The mean change in FEV1 following adequate beta-blockade was 0.05+/-0.24 liters (95% CI -0.06 to +1.61), p=0.35, giving a mean percentage change of 3.18%+/-11.66 (95% CI -2.26 to 8.62). CONCLUSIONS: Previously held concerns about worsening pulmonary function through the short-term use of beta-blockers should not dissuade their perioperative usage in patients with peripheral vascular disease. Furthermore, the accuracy of pulmonary function tests in preoperative assessment and risk stratification also appears unaffected by this therapy. 相似文献
10.
What should nurse teachers be doing? A preliminary study 总被引:1,自引:0,他引:1
Heather A. Cahill BSc RGN RMN RCNT RNT Cert Ed 《Journal of advanced nursing》1997,26(1):146-153
There is little doubt that the role of the nurse teacher is complex and multifaceted in nature. The apparently conflicting demands of NHS trusts and education in the United Kingdom, at the time of integration of nurse education into the higher education sector, further complicates the role. This recognition underlines the need to capture and measure key aspects of nurse teacher function in order to maximize educational gain. Using a comprehensive literature review, focus group discussions and a small number of individual semi-structured interviews, this preliminary study explored the issue of teacher workload, from the perspective of the principal stakeholders in nurse and higher education. Competing research and clinical practice objectives for nurse teachers are identified against a background of changing health care provision, reduced availability of placements and an increased need for evidence-based practice. 相似文献