全文获取类型
收费全文 | 1367篇 |
免费 | 174篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 12篇 |
儿科学 | 49篇 |
妇产科学 | 11篇 |
基础医学 | 175篇 |
口腔科学 | 44篇 |
临床医学 | 128篇 |
内科学 | 297篇 |
皮肤病学 | 16篇 |
神经病学 | 130篇 |
特种医学 | 135篇 |
外科学 | 169篇 |
综合类 | 47篇 |
预防医学 | 171篇 |
眼科学 | 12篇 |
药学 | 87篇 |
肿瘤学 | 65篇 |
出版年
2022年 | 15篇 |
2021年 | 23篇 |
2020年 | 9篇 |
2019年 | 23篇 |
2018年 | 32篇 |
2017年 | 14篇 |
2016年 | 22篇 |
2015年 | 14篇 |
2014年 | 29篇 |
2013年 | 44篇 |
2012年 | 49篇 |
2011年 | 68篇 |
2010年 | 35篇 |
2009年 | 27篇 |
2008年 | 45篇 |
2007年 | 60篇 |
2006年 | 42篇 |
2005年 | 73篇 |
2004年 | 56篇 |
2003年 | 73篇 |
2002年 | 68篇 |
2001年 | 51篇 |
2000年 | 46篇 |
1999年 | 32篇 |
1998年 | 30篇 |
1997年 | 30篇 |
1996年 | 24篇 |
1995年 | 22篇 |
1994年 | 23篇 |
1993年 | 24篇 |
1992年 | 41篇 |
1991年 | 32篇 |
1990年 | 40篇 |
1989年 | 31篇 |
1988年 | 35篇 |
1987年 | 22篇 |
1986年 | 20篇 |
1985年 | 26篇 |
1984年 | 15篇 |
1983年 | 12篇 |
1982年 | 20篇 |
1980年 | 11篇 |
1978年 | 9篇 |
1977年 | 8篇 |
1976年 | 11篇 |
1975年 | 10篇 |
1969年 | 9篇 |
1968年 | 9篇 |
1967年 | 8篇 |
1966年 | 11篇 |
排序方式: 共有1548条查询结果,搜索用时 15 毫秒
991.
992.
Marci H Levine Allison L Goddard Thomas B Dodson 《Journal of oral and maxillofacial surgery》2007,65(3):470-474
PURPOSE: To document a clinically relevant position of the inferior alveolar nerve (IAN) in dentate patients and identify patient factors associated with IAN position. MATERIALS AND METHODS: The investigators used a cross-sectional study design and a study sample of subjects who had a radiographically identifiable IAN canal and at least 1 mandibular first molar was enrolled. Predictor variables were age, gender, and race. Outcome variables were the linear distances between the buccal aspect of the IAN canal and the outer buccal cortical margin of the mandible, and the superior aspect of the IAN canal and the alveolar crest. Appropriate uni-, bi-, and multivariate statistics were computed. RESULTS: The study sample was composed of 50 patients with a mean age of 42 years, 42.0% were male, and 73.2% were white. On average, the buccal aspect of the canal was 4.9 mm from the buccal cortical margin of the mandible. The superior aspect of the IAN canal was 17.4 mm inferior from the alveolar crest. Age and race were statistically associated with IAN position relative to the buccal cortical mandibular margin (P<.05). None of the demographic variables were associated with vertical position. CONCLUSIONS: The IAN canal was 4.9 mm and 17.4 mm from the buccal and superior cortical surfaces of the mandible, respectively. The bucco-lingual IAN canal position was associated with age and race. Older patients and white patients, on average, have less distance between the buccal aspect of the canal and the buccal mandibular border. To minimize the risk of IAN injury, these variables should be considered when planning mandibular osteotomies or using monocortical plates. 相似文献
993.
The assessment of carotid atherosclerotic disease is an essential pre-requisite for determining a patients suitability for carotid endarterectomy to prevent ischaemic stroke. Catheter angiography is regarded as the most accurate investigative tool for this purpose. However, with its finite morbidity and invasiveness, there is an increasing reliance upon non-invasive methods to accurately assess carotid disease. We present a review of the technique and applications of computed tomography angiography. 相似文献
994.
Genetic analysis and functional characterization of prothrombins Corpus Christi (Arg382-Cys), Dhahran (Arg271-His), and hypoprothrombinemia 总被引:3,自引:2,他引:1
O'Marcaigh AS; Nichols WL; Hassinger NL; Mullins JD; Mallouh AA; Gilchrist GS; Owen WG 《Blood》1996,88(7):2611-2618
The structural abnormalities and functional characteristics of dysfunctional prothrombin variants in two new kindreds have been determined. Prothrombin Corpus Christi (family 1) was purified and found to have markedly reduced fibrinogen clotting activity, yet normal amidolytic and near-normal platelet aggregating activity. A transition (C to T) at nucleotide position 8885, present in the heterozygous form in affected family members, resulted in the substitution of Cys for Arg 382. This substitution results in the loss of a positive charge within the fibrinogen-binding exosite of thrombin, thus accounting for the observed functional defect. A heterozygous C to T transition was also present at position 19994 in other family members with a hypoprothrombinemic phenotype. This mutation results in the replacement of Gln 541 (CAA) by a premature stop codon (TAA). Prothrombin Dhahran (family 2) was found to have markedly reduced fibrinogen clotting activity, but normal amidolytic activity. Affected family members were found to have a G to A transition at nucleotide position 7312 resulting in the substitution of His for Arg 271. This substitution results in the abolition of a factor Xa cleavage site, yielding meizothrombin rather than thrombin, on activation of prothrombin Dhahran by factor Xa. All but one of the above mutations occur at CpG dinucleotides, thus further supporting the observation of a high incidence of CpG transitions in hereditary dysprothrombinemia. The significant bleeding tendencies of individuals homozygous for prothrombin Dhahran (prothrombin clotting activity 5% to 7%) contrast sharply with the absence of significant chronic bleeding in the proband expressing prothrombin Corpus Christi (prothrombin clotting activity 2%). Our findings underscore the capacity of thrombin to contribute to clinical hemostasis by mechanisms other than its fibrinogen clotting activity. 相似文献
995.
Adrian Ooi Andrew T. Goodwin Martin Goddard Andrew J. Ritchie 《European journal of cardio-thoracic surgery》2003,23(6):878-882
Objectives: The role of post-mortem following thoracic surgery has not been previously studied. Most importantly, the clinical diagnosis of thoracic surgical mortality cannot be certain unless post-mortem analysis has been performed. Methods: Consecutive post-mortem data were collected on 110 patients between 1992 and 2001 (66.3% of all in-hospital thoracic surgical deaths). Clinically attributed causes of death were compared with post-mortem findings. Results: A total of 4302 thoracic operations were performed during the 10-year period, with overall mortality 3.8%. The mean age was 63.6 years (range 21–87) with 73.6% male. In the 110 patients undergoing post-mortem examination, the operations performed were pneumonectomy 24.5%, lobectomy 14.5%, oesophagectomy 12.7%, lung biopsy 8.2%, pleurectomy/bullectomy 6.4%, decortication 4.5%, lung volume reduction 1.8%, other thoracic 13.6%, other oesophageal 9.1%, and other procedures 4.5%. The mean time to death was 12.5 days (range 0–85). The causes of death were respiratory 47.3%, cardiac 16.4%, multiple organ failure 8.2%, sepsis 6.4%, gastrointestinal 4.5%, haemorrhage/technical failure 10%, and others 7.3%. Post-mortem revealed an unsuspected cause of death in 34 (31%) patients, comprising pulmonary 17, cardiac 5, gastrointestinal 3, haemorrhage/technical failure 2, multiple organ failure 2 and other 5. Conclusion: Post-mortem determined unsuspected diagnoses in a high proportion of patients undergoing thoracic surgery. Post-mortem continues to be the ‘gold standard’ method for attributing the cause of death. Accurate outcome data following thoracic surgery are essential for proper audit, and hence for improvements in clinical practice to occur. 相似文献
996.
997.
Richard J Harvey John C Goddard Sarah K Wise Rodney J Schlosser 《Otolaryngology--head and neck surgery》2008,139(1):137-142
OBJECTIVE: Assess paranasal sinus distribution of topical solutions following endoscopic sinus surgery (ESS) using various delivery devices. STUDY DESIGN: Experimental prospective study. SUBJECTS AND METHODS: Ten cadaver sinus systems were irrigated with Gastroview before surgery, after ESS, and after medial maxillectomy. Delivery was via pressurized spray (NasaMist), neti pot (NasaFlo), and squeeze bottle (Sinus Rinse). Scans were performed before and after each delivery with a portable CT machine (Xoran xCAT), and blinded assessments were made for distribution to individual sinuses. RESULTS: Total sinus distribution was greater post-ESS (P < 0.001). Additional distribution was gained with medial maxillectomy (P = 0.02). Influence of delivery device on distribution was significantly higher with neti pot > squeeze bottle > pressurized spray (P < 0.001). Frontal sinus penetration was greatest after surgery (P = 0.001). CONCLUSION: ESS greatly enhances the delivery of nasal solutions, regardless of delivery device. Pressurized spray solutions in un-operated sinuses provide little more than nasal cavity distribution. Use of squeeze bottle/neti pot post-ESS offers a greatly enhanced ability to deliver solutions to the paranasal sinuses. 相似文献
998.
The polymorphism which determines expression of Kell and Cellano antigens on the red-cell surface has been reported to be a single C→T nucleotide substitution at residue 701 where T codes for the presence of Kell antigen. This was confirmed by the direct automated sequencing of PCR products amplified from individuals of known Kell phenotype. The substitution creates a Bsm I restriction enzyme site and this has formed the basis for the development of a PCR-based diagnostic assay for the determination of Kell phenotype in samples of donor blood. The assay is based on RFLP analysis of coamplified PCR products, one of which spans the K/k polymorphic site, and one control fragment which contains a Bsm I site. Digestion of the PCR products with Bsm I restriction enzyme and subsequent gel analysis of the digest allowed unequivocal determination of the K/k status of all of the samples tested. 相似文献
999.
1000.
A. Kent K. L. Goddard P. A. H. van den Berk F. J. Raphael S. E. McCluskey J. H. Lacey 《Acta psychiatrica Scandinavica》1997,95(2):140-144
Measures of abnormal eating behaviour in 48 women referred for psychiatric assessment following an act of deliberate self-poisoning (subjects) were compared with those in 50 women attending an accident and emergency department following minor accidental injury (controls). Disordered eating behaviour was significantly more prevalent in the subject group, even when the effect of depression was removed. Four subjects fulfilled the diagnostic criteria for bulimia nervosa, but none of the subjects met the diagnostic criteria for anorexia nervosa. The prevalence of obesity was the same in both subject and control groups. The degree of abnormal eating was very strongly correlated with a measure of inwardly directed irritability in both subjects and controls, and was strongly associated with measures of impulsiveness, outwardly directed irritability and anxiety in subjects. 相似文献