全文获取类型
收费全文 | 3669篇 |
免费 | 309篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 45篇 |
儿科学 | 117篇 |
妇产科学 | 55篇 |
基础医学 | 583篇 |
口腔科学 | 41篇 |
临床医学 | 456篇 |
内科学 | 696篇 |
皮肤病学 | 70篇 |
神经病学 | 324篇 |
特种医学 | 82篇 |
外科学 | 499篇 |
综合类 | 27篇 |
一般理论 | 2篇 |
预防医学 | 445篇 |
眼科学 | 103篇 |
药学 | 214篇 |
中国医学 | 7篇 |
肿瘤学 | 219篇 |
出版年
2023年 | 43篇 |
2022年 | 64篇 |
2021年 | 155篇 |
2020年 | 100篇 |
2019年 | 149篇 |
2018年 | 147篇 |
2017年 | 110篇 |
2016年 | 107篇 |
2015年 | 123篇 |
2014年 | 180篇 |
2013年 | 225篇 |
2012年 | 324篇 |
2011年 | 308篇 |
2010年 | 153篇 |
2009年 | 124篇 |
2008年 | 188篇 |
2007年 | 198篇 |
2006年 | 170篇 |
2005年 | 146篇 |
2004年 | 135篇 |
2003年 | 117篇 |
2002年 | 120篇 |
2001年 | 54篇 |
2000年 | 65篇 |
1999年 | 40篇 |
1998年 | 29篇 |
1997年 | 22篇 |
1996年 | 14篇 |
1995年 | 18篇 |
1994年 | 14篇 |
1993年 | 12篇 |
1992年 | 34篇 |
1991年 | 16篇 |
1990年 | 16篇 |
1989年 | 21篇 |
1988年 | 29篇 |
1987年 | 19篇 |
1986年 | 14篇 |
1985年 | 26篇 |
1984年 | 13篇 |
1983年 | 15篇 |
1982年 | 10篇 |
1981年 | 12篇 |
1979年 | 16篇 |
1977年 | 7篇 |
1976年 | 9篇 |
1974年 | 11篇 |
1973年 | 7篇 |
1969年 | 7篇 |
1966年 | 6篇 |
排序方式: 共有3985条查询结果,搜索用时 0 毫秒
1.
Eloise R. Galligan Lindsey Fix Sameera Husain Philip Zachariah Darrell J. Yamashiro Christine T. Lauren 《Journal of cutaneous pathology》2019,46(2):159-161
We report a case of disseminated Trichosporon asahii in a patient on systemic antifungal therapy who presented with multiple cutaneous nodules suggestive of fungal infection. Histologic features resembled neutrophilic eccrine hidradenitis but staining with periodic acid‐Schiff and Gomori methenamine silver confirmed the clinical diagnosis. This case highlights the importance of maintaining suspicion for trichosporonosis and contextualizing histologic findings within the underlying clinical picture. 相似文献
2.
3.
Rebecca P. Ang Robert M. Klassen Wan Har Chong Vivien S. Huan Isabella Y.F. Wong Lay See Yeo Lindsey L. Krawchuk 《Journal of adolescence》2009,32(5):1225-1237
We provide further evidence for the two-factor structure of the 9-item Academic Expectations Stress Inventory (AESI) using confirmatory factor analysis on a sample of 289 Canadian adolescents and 310 Singaporean adolescents. Examination of measurement invariance tests the assumption that the model underlying a set of scores is directly comparable across groups. This study also examined the cross-cultural validity of the AESI using multigroup confirmatory factor analysis across both the Canadian and Singaporean adolescent samples. The results suggested cross-cultural invariance of form, factor loadings, and factor variances and covariances of the AESI across both samples. Evidence of AESI's convergent and discriminant validity was also reported. Findings from t-tests revealed that Singaporean adolescents reported a significantly higher level of academic stress arising from self expectations, other expectations, and overall academic stress, compared to Canadian adolescents. Also, a larger cross-cultural effect was associated with academic stress arising from other expectations compared with academic stress arising from self expectations. 相似文献
4.
A rapid, inexpensive beryllium acute toxicity assay using human erythrocyte ATP levels has been developed. The assay uses a photometric measurement of the luciferin-luciferase reaction in erythrocytes incubated in HEPES buffer with the tested toxicant. Incubation in HEPES significantly increases the sensitivity of erythrocytes to beryllium when compared to incubation in either plasma or physiological saline. After a one-hour incubation period in HEPES buffer and beryllium there is a loss of 50% of the erythrocyte ATP at 3 micrograms/ml of beryllium, and an 80% loss of ATP at 5 micrograms/ml of beryllium. The source of human erythrocytes does not appear to influence the test. Erythrocytes from 10 individuals, one with chronic beryllium disease and another with an acute sensitivity to beryllium, all gave similar biphasic dose-response curves to beryllium. 相似文献
5.
Median nerve somatosensory evoked potentials (SEPs) were monitored in patients with chronic pain before and after stellate ganglion blockade. A change caused by the syndrome or by the block would suggest that SEPs might be useful in the diagnosis and treatment of chronic pain. We observed 20 subjects. Group I (n = 10) had chronic pain not involving the upper extremity. Group II (n = 8) had reflex sympathetic dystrophy of the arm. All patients underwent unilateral stellate ganglion block using an anterior paratracheal approach. The SEPs were recorded by median nerve stimulation on the blocked (affected) side and unblocked (unaffected) side before and 30 min after the block. Recording sites were ipsilateral brachial plexus, the cervical spinal cord, and the contralateral sensory cortex. There were no between-group differences before or after the block. Paired analysis within each group showed that the SEPs were not different from baseline (unaffected side before block) at any time throughout the study. We conclude that since SEPs are not changed by the reflex sympathetic dystrophy or stellate ganglion block, they would not be useful in the evaluation of pain or in determining the effectiveness of sympathetic block. Both the pain and the block appear to involve alteration of conducting pathways separate from those monitored by median nerve SEPs. 相似文献
6.
7.
A 54-year old man presented with multiple pulmonary emboli and an incidental finding of a huge left ventricular thrombus. Transthoracic echo images demonstrated a globally dilated heart with very poor left ventricular function. It was elected to manage the patient medically, and he was commenced on warfarin therapy, resulting in completed resolution of the thrombus over 10 weeks. No underlying cause was found and he did not experience any further embolic events. This illustrates a rare case of a large ventricular thrombus in a patient with no underlying risk factors. 相似文献
8.
9.
Karen W. Gripp Lindsey A. Morse Marni Axelrad Kathryn C. Chatfield Aaron Chidekel William Dobyns Daniel Doyle Bronwyn Kerr Angela E. Lin David D. Schwartz Barbara J. Sibbles Dawn Siegel Suma P. Shankar David A. Stevenson Mihir M. Thacker K. Nicole Weaver Sue M. White Katherine A. Rauen 《American journal of medical genetics. Part A》2019,179(9):1725-1744
Costello syndrome (CS) is a RASopathy caused by activating germline mutations in HRAS. Due to ubiquitous HRAS gene expression, CS affects multiple organ systems and individuals are predisposed to cancer. Individuals with CS may have distinctive craniofacial features, cardiac anomalies, growth and developmental delays, as well as dermatological, orthopedic, ocular, and neurological issues; however, considerable overlap with other RASopathies exists. Medical evaluation requires an understanding of the multifaceted phenotype. Subspecialists may have limited experience in caring for these individuals because of the rarity of CS. Furthermore, the phenotypic presentation may vary with the underlying genotype. These guidelines were developed by an interdisciplinary team of experts in order to encourage timely health care practices and provide medical management guidelines for the primary and specialty care provider, as well as for the families and affected individuals across their lifespan. These guidelines are based on expert opinion and do not represent evidence‐based guidelines due to the lack of data for this rare condition. 相似文献
10.
Mutation analysis of the spastin gene (SPG4) in patients with hereditary spastic paraparesis 总被引:8,自引:2,他引:8 下载免费PDF全文
Lindsey JC Lusher ME McDermott CJ White KD Reid E Rubinsztein DC Bashir R Hazan J Shaw PJ Bushby KM 《Journal of medical genetics》2000,37(10):759-765
BACKGROUND—Hereditary spastic paraparesis is a genetically heterogeneous condition. Recently, mutations in the spastin gene were reported in families linked to the common SPG4 locus on chromosome 2p21-22.
OBJECTIVES—To study a population of patients with hereditary spastic paraparesis for mutations in the spastin gene (SPG4) on chromosome 2p21-22.
METHODS—DNA from 32 patients (12 from families known to be linked to SPG4) was analysed for mutations in the spastin gene by single strand conformational polymorphism analysis and sequencing. All patients were also examined clinically.
RESULTS—Thirteen SPG4 mutations were identified, 11 of which are novel. These mutations include missense, nonsense, frameshift, and splice site mutations, the majority of which affect the AAA cassette. We also describe a nucleotide substitution outside this conserved region which appears to behave as a recessive mutation.
CONCLUSIONS—Recurrent mutations in the spastin gene are uncommon. This reduces the ease of mutation detection as a part of the diagnostic work up of patients with hereditary spastic paraparesis. Our findings have important implications for the presumed function of spastin and schemes for mutation detection in HSP patients.
Keywords: spastin; hereditary spastic paraparesis; mutation; recessive 相似文献
OBJECTIVES—To study a population of patients with hereditary spastic paraparesis for mutations in the spastin gene (SPG4) on chromosome 2p21-22.
METHODS—DNA from 32 patients (12 from families known to be linked to SPG4) was analysed for mutations in the spastin gene by single strand conformational polymorphism analysis and sequencing. All patients were also examined clinically.
RESULTS—Thirteen SPG4 mutations were identified, 11 of which are novel. These mutations include missense, nonsense, frameshift, and splice site mutations, the majority of which affect the AAA cassette. We also describe a nucleotide substitution outside this conserved region which appears to behave as a recessive mutation.
CONCLUSIONS—Recurrent mutations in the spastin gene are uncommon. This reduces the ease of mutation detection as a part of the diagnostic work up of patients with hereditary spastic paraparesis. Our findings have important implications for the presumed function of spastin and schemes for mutation detection in HSP patients.
Keywords: spastin; hereditary spastic paraparesis; mutation; recessive 相似文献