全文获取类型
收费全文 | 27662篇 |
免费 | 2129篇 |
国内免费 | 90篇 |
专业分类
耳鼻咽喉 | 383篇 |
儿科学 | 615篇 |
妇产科学 | 620篇 |
基础医学 | 3407篇 |
口腔科学 | 510篇 |
临床医学 | 2688篇 |
内科学 | 5908篇 |
皮肤病学 | 418篇 |
神经病学 | 2770篇 |
特种医学 | 1121篇 |
外国民族医学 | 2篇 |
外科学 | 4142篇 |
综合类 | 428篇 |
一般理论 | 23篇 |
预防医学 | 2412篇 |
眼科学 | 687篇 |
药学 | 1715篇 |
1篇 | |
中国医学 | 48篇 |
肿瘤学 | 1983篇 |
出版年
2022年 | 181篇 |
2021年 | 383篇 |
2020年 | 245篇 |
2019年 | 422篇 |
2018年 | 449篇 |
2017年 | 355篇 |
2016年 | 397篇 |
2015年 | 515篇 |
2014年 | 661篇 |
2013年 | 1040篇 |
2012年 | 1469篇 |
2011年 | 1544篇 |
2010年 | 863篇 |
2009年 | 801篇 |
2008年 | 1364篇 |
2007年 | 1608篇 |
2006年 | 1645篇 |
2005年 | 1646篇 |
2004年 | 1507篇 |
2003年 | 1489篇 |
2002年 | 1429篇 |
2001年 | 483篇 |
2000年 | 517篇 |
1999年 | 526篇 |
1998年 | 332篇 |
1997年 | 323篇 |
1996年 | 249篇 |
1995年 | 247篇 |
1994年 | 236篇 |
1993年 | 239篇 |
1992年 | 359篇 |
1991年 | 350篇 |
1990年 | 355篇 |
1989年 | 338篇 |
1988年 | 347篇 |
1987年 | 293篇 |
1986年 | 336篇 |
1985年 | 322篇 |
1984年 | 283篇 |
1983年 | 291篇 |
1982年 | 238篇 |
1981年 | 229篇 |
1980年 | 221篇 |
1979年 | 234篇 |
1978年 | 187篇 |
1977年 | 195篇 |
1976年 | 155篇 |
1975年 | 156篇 |
1974年 | 199篇 |
1973年 | 160篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Mary Ann Richardson Helen M Chao Laura L Read James D Clelland Raymond F Suckow 《American journal of medical genetics. Part B, Neuropsychiatric genetics》2006,(2):195-197
Phenylketonuria (PKU), an inborn error of phenylalanine metabolism, has been shown to be a risk factor for tardive dyskinesia (TD). In male psychiatric patients there was a significant relationship between TD and measures of plasma phenylalanine following ingestion of a standardized phenylalanine dose that was indicative of higher brain availability of phenylalanine in patients with TD. In addition, a medical food formulation consisting of branched chain amino acids, which compete with phenylalanine for transport across the blood-brain barrier, has been demonstrated to be an efficacious treatment for TD. Cumulatively these findings suggested that TD was related to phenylalanine metabolism and thus that sequence variants in the gene for phenylalanine hydroxylase (PAH), the rate-limiting enzyme in the catabolism of phenylalanine, could be associated with TD susceptibility. Genetic screening of PAH in a group of 123 psychiatric patients revealed ten sequence polymorphisms and two mutations, but none appeared to be a significant risk factor for TD. 相似文献
3.
4.
C. M. Gordon E. Binello M. S. LeBoff M. E. Wohl C. J. Rosen A. A. Colin 《Osteoporosis international》2006,17(5):783-790
Introduction Patients with cystic fibrosis (CF) are known to be at risk for early osteoporosis, and the mechanisms that mediate bone loss
are still being delineated. The aim of the present investigation was to investigate if a correlation exists in these patients
between skeletal measurements by dual-energy x-ray absorptiometry (DXA) and two anabolic factors, dehydroepiandrosterone (DHEA)
and insulin-like growth factor I (IGF-I), and proresorptive factors such as the cytokines interleukin-1β, tumor necrosis factor α,
and interleukin-6.
Methods We studied 32 outpatients (18 females; mean age: 26.2 ± 7.9 years) at a tertiary care medical center. The subjects had venous
samples obtained, underwent anthropometric and bone mineral density (BMD) measurements, and completed a health survey. Serum
IGF-I concentrations were below the age-adjusted mean in 78% of the participants, and DHEA sulfate (DHEAS) concentrations
were low in 72%. Serum concentrations of all cytokines were on the low side of normal; nonetheless, there was a modest inverse
correlation between IL-1β and BMD at all sites.
Results In univariate analyses, IGF-I and DHEAS were significant correlates of BMD or bone mineral content. In final multivariate
models controlling for anthropometric and other variables of relevance to bone density, only IGF-I was identified as a significant
independent skeletal predictor. While alterations in DHEAS, IGF-I, and specific cytokines may contribute to skeletal deficits
in patients with CF, of these factors a low IGF-I concentration appears to be most strongly correlated with BMD.
Conclusions These findings may have therapeutic implications for enhancing bone density in these patients. 相似文献
5.
6.
Comparison of ThinPrep versus conventional smear cytopreparatory techniques for fine-needle aspiration specimens of head and neck masses. 总被引:2,自引:0,他引:2
Lloyd Ford Barry M Rasgon Raymond L Hilsinger Raul M Cruz Karen Axelsson Gregory J Rumore Thomas M Schmidtknecht Balaram Puligandla John Sawicki William Pshea 《Otolaryngology--head and neck surgery》2002,126(5):554-561
OBJECTIVES: Diagnostic accuracy of the ThinPrep process (Cytyc, Boxborough, MA) was compared with that of conventional (smear) cytopreparation for fine-needle aspiration (FNA) of head and neck masses. METHODS: In a prospective, randomized, single-blinded study, 209 patients served as their own controls and underwent 236 FNAs using ThinPrep and conventional (smear) cytopreparatory techniques. RESULTS: ThinPrep produced less air-drying artifact and less mechanical distortion than the conventional method. The conventional technique was diagnostic in 63% of samples; the ThinPrep technique was diagnostic in 55% of samples. When all results were combined, pathologists subjectively preferred the conventional technique but accepted use of ThinPrep as the only cytopreparatory technique for most head and neck masses. CONCLUSIONS: For adequately experienced cytopathologists, ThinPrep is acceptable for FNA of salivary masses, neck cysts, metastatic lymph nodes, and thyroid lesions. Conventional smear technique should be used for FNA of nonmetastatic lymphoid lesions. Use of ThinPrep can complement use of the conventional (smear) cytopreparatory technique when aspirate is nondiagnostic or bloody, when the patient has a blood-borne infectious disease, when the clinician is inexperienced, or when aspirate has entered the syringe. 相似文献
7.
Scott A Fields Elizabeth Morrison Ernie Yoder Kevin Krane Thomas Agresta Rich Esham Frederick McCurdy Jonathan Rosen James Shumway 《Academic medicine》2002,77(6):543-546
PURPOSE: Chart notes are used to support billing codes under the evaluation and management guidelines of the Health Care Financing Administration (HCFA), in addition to serving as a record of the visit. To better understand the effect of the HCFA documentation guidelines, the authors collected data on how the guidelines affect participation by university- and community-based faculty in clinical education programs. METHOD: In 2000, the authors sent six copies of their questionnaire to the associate deans of the 125 U.S. medical schools and requested they distribute them to all core clerkship directors. The questionnaire consisted of multiple-choice and short-answer questions regarding documentation of medical visits, participation of community-based faculty, understanding of HCFA documentation guidelines, and effects on education programs. RESULTS: The response rate was about 50%. Most of the 379 clerkship directors who responded (77%) stated they were aware the HCFA documentation guidelines include specifications regarding the role medical students can play and documentation of medical visits, and 64% indicated they were concerned the guidelines would affect their educational programs. Concerns included the loss of student independence and active participation in the patient care environment (37), time constraints and the changing balance between education and service (16), loss of faculty and decreased morale (11), and decreased quality of care for patients (7). CONCLUSION: Leaders of medical education must work to modify these guidelines to protect the quality of patients' care, while maximizing students' educational opportunity and participation. 相似文献
8.
Raymond E B Anakwe 《European journal of emergency medicine》2005,12(3):133-135
Traumatic aortic transection is an uncommon but often fatal injury. It is typically a high energy injury and may occur in the multiply injured patient. This injury is often missed. There is evidence that airbags and seat belts protect against these injuries. We present the case of a patient who survived. 相似文献
9.
10.