全文获取类型
收费全文 | 51029篇 |
免费 | 3619篇 |
国内免费 | 171篇 |
专业分类
耳鼻咽喉 | 537篇 |
儿科学 | 1207篇 |
妇产科学 | 717篇 |
基础医学 | 6683篇 |
口腔科学 | 970篇 |
临床医学 | 4780篇 |
内科学 | 10727篇 |
皮肤病学 | 661篇 |
神经病学 | 5651篇 |
特种医学 | 1990篇 |
外国民族医学 | 3篇 |
外科学 | 7444篇 |
综合类 | 988篇 |
一般理论 | 86篇 |
预防医学 | 4538篇 |
眼科学 | 1042篇 |
药学 | 3319篇 |
1篇 | |
中国医学 | 64篇 |
肿瘤学 | 3411篇 |
出版年
2023年 | 183篇 |
2022年 | 322篇 |
2021年 | 756篇 |
2020年 | 433篇 |
2019年 | 768篇 |
2018年 | 916篇 |
2017年 | 679篇 |
2016年 | 770篇 |
2015年 | 943篇 |
2014年 | 1339篇 |
2013年 | 2137篇 |
2012年 | 3184篇 |
2011年 | 3371篇 |
2010年 | 1828篇 |
2009年 | 1751篇 |
2008年 | 3134篇 |
2007年 | 3460篇 |
2006年 | 3462篇 |
2005年 | 3679篇 |
2004年 | 3277篇 |
2003年 | 3073篇 |
2002年 | 3077篇 |
2001年 | 565篇 |
2000年 | 477篇 |
1999年 | 592篇 |
1998年 | 659篇 |
1997年 | 638篇 |
1996年 | 545篇 |
1995年 | 531篇 |
1994年 | 455篇 |
1993年 | 449篇 |
1992年 | 390篇 |
1991年 | 385篇 |
1990年 | 373篇 |
1989年 | 355篇 |
1988年 | 352篇 |
1987年 | 328篇 |
1986年 | 316篇 |
1985年 | 314篇 |
1984年 | 380篇 |
1983年 | 386篇 |
1982年 | 424篇 |
1981年 | 420篇 |
1980年 | 373篇 |
1979年 | 218篇 |
1978年 | 232篇 |
1977年 | 186篇 |
1976年 | 184篇 |
1975年 | 142篇 |
1974年 | 177篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
22.
23.
24.
Hillary R Bogner Mark S Cary Martha L Bruce Charles F Reynolds Benoit Mulsant Thomas Ten Have George S Alexopoulos 《The American journal of geriatric psychiatry》2005,13(10):861-868
OBJECTIVE: The authors described the influence of specific medical conditions on clinical remission and response of major depression (MDD) in a clinical trial evaluating a care-management intervention among older primary-care patients. METHODS: Adults age 60 years and older were randomly selected and screened for depression. Participants were randomly assigned to Usual Care or to an Intervention with a depression care-manager offering algorithm-based care for MDD. In all, 324 adults meeting criteria for MDD were included in these analyses. Remission and response was defined by a score on the Hamilton Rating Scale for Depression <10 and by a decrease from baseline of > or =50%, respectively. Medical comorbidity was ascertained through self-report. Cognitive impairment was defined by a score <24 on the Mini-Mental State Exam (MMSE). RESULTS: In Usual Care, rates of remission were faster in persons who reported atrial fibrillation (AF) than in persons who did not report AF and slower in persons who reported chronic pulmonary disease than in persons who did not report chronic pulmonary disease; rates of response were less stable in persons with MMSE <24 than in those with MMSE > or =24. In the Intervention condition, none of the specific chronic medical conditions were significantly associated with outcomes for MDD. CONCLUSIONS: Because disease-specific findings were observed in persons who received Usual Care but not in persons who received more intensive treatment in the Intervention condition, our results suggest that the association of medical comorbidity and treatment outcomes for MDD may be determined by the intensity of treatment for depression. 相似文献
25.
Marcus P Kennedy Raymond D Coakley Scott H Donaldson Robert M Aris Kathy Hohneker Joel P Wedd Michael R Knowles Peter H Gilligan James R Yankaskas 《Journal of cystic fibrosis》2007,6(4):267-273
BACKGROUND: The impact of infection with Burkholderia gladioli in cystic fibrosis, other chronic airway diseases and immunosuppressed patients is unknown. METHODS: A six-year retrospective review of all patients with B. gladioli infection was performed in a tertiary referral center with cystic fibrosis and lung transplantation programs. In addition, a targeted survey of all 251 lung transplant recipients was performed. Available B. gladioli isolates were analyzed via pulsed field gel electrophoresis. RESULTS: Thirty-five patients were culture positive for B. gladioli, including 33 CF patients. No bacteremia was identified. Isolates were available in 18 patients and all were genetically distinct. Two-thirds of these isolates were susceptible to usual anti-pseudomonal antibiotics. After acquisition, only 40% of CF patients were chronically infected (> or =2 positive cultures separated by at least 6 months). Chronic infection was associated with resistance to > or =2 antibiotic groups on initial culture and failure of eradication after antibiotic therapy. The impact of acquisition of B. gladioli infection in chronic infection was variable. Three CF patients with chronic infection underwent lung transplantation. One post-transplant patient developed a B. gladioli mediastinal abscess, which was treated successfully. CONCLUSIONS: The majority of patients' culture positive for B. gladioli at our center have CF. B. gladioli infection is often transient and is compatible with satisfactory post-lung transplantation outcomes. 相似文献
26.
Robert M. Levy Roman Saikovsky Evgeniya Shmidt Alexander Khokhlov Bruce P. Burnett 《Nutrition Research》2009
Flavocoxid (Limbrel), a proprietary mixture of flavonoid molecules (baicalin and catechin), was tested against a traditional nonsteroidal anti-inflammatory drug, naproxen, for the management of the signs and symptoms of moderate osteoarthritis (OA) in humans. Discomfort and global disease activity were used as the primary end points, and safety assessments were also taken for both treatments as a secondary endpoint. In this double-blind study, 103 subjects were randomly assigned to receive either flavocoxid [500 mg twice daily (BID)] or naproxen (500 mg BID) in a 1-month onset of action trial. Outcome measures included the short Western Ontario and McMaster University Osteoarthritis Index, subject Visual Analogue Scale for discomfort and global response, and investigator Visual Analogue Scale for global response and fecal occult blood. Both flavocoxid and naproxen showed significant reduction in the signs and symptoms of knee OA (P ≤ .001). There were no statistically detectable differences between the flavocoxid and naproxen groups with respect to any of the outcome variables. Similarly, there were no statistically detectable differences between the groups with respect to any adverse event, although there was a trend toward a higher incidence of edema and nonspecific musculoskeletal discomfort in the naproxen group. In this short-term pilot study, flavocoxid was as effective as naproxen in controlling the signs and symptoms of OA of the knee and would present a safe and effective option for those individuals on traditional nonsteroidal anti-inflammatory drugs or cyclooxygenase-2 inhibitors. A low incidence of adverse events was reported for both groups. 相似文献
27.
28.
Bruce Chabner 《Clinical cancer research》2007,13(8):2307-2308
29.
David G Hicks Brian J Yoder Sarah Short Shannon Tarr Nichole Prescott Joseph P Crowe Andrea E Dawson G Thomas Budd Steven Sizemore Muzaffer Cicek Toni K Choueiri Raymond R Tubbs Daniel Gaile Norma Nowak Mary Ann Accavitti-Loper Andra R Frost Danny R Welch Graham Casey 《Clinical cancer research》2006,12(22):6702-6708
PURPOSE: This study aims to determine the effect of loss of breast cancer metastasis suppressor 1 (BRMS1) protein expression on disease-free survival in breast cancer patients stratified by estrogen receptor (ER), progesterone receptor (PR), or HER2 status, and to determine whether loss of BRMS1 protein expression correlated with genomic copy number changes. EXPERIMENTAL DESIGN: A tissue microarray immunohistochemical analysis was done on tumors of 238 newly diagnosed breast cancer patients who underwent surgery at the Cleveland Clinic between January 1, 1995 and December 31, 1996, and a comparison was made with 5-year clinical follow-up data. Genomic copy number changes were determined by array-based comparative genomic hybridization in 47 breast cancer cases from this population and compared with BRMS1 staining. RESULTS: BRMS1 protein expression was lost in nearly 25% of cases. Patients with tumors that were PR negative (P=0.006) or HER2 positive (P=0.039) and <50 years old at diagnosis (P=0.02) were more likely to be BRMS1 negative. No overall correlation between BRMS1 staining and disease-free survival was observed. A significant correlation, however, was seen between loss of BRMS1 protein expression and reduced disease-free survival when stratified by either loss of ER (P=0.008) or PR (P=0.029) or HER2 overexpression (P=0.026). Overall, there was poor correlation between BRMS1 protein staining and copy number status. CONCLUSIONS: These data suggest a mechanistic relationship between BRMS1 expression, hormone receptor status, and HER2 growth factor. BRMS1 staining could potentially be used in patient stratification in conjunction with other prognostic markers. Further, mechanisms other than genomic deletion account for loss of BRMS1 gene expression in breast tumors. 相似文献
30.
Raymond Tubbs James Pettay Richard Powell David G Hicks Patrick Roche William Powell Thomas Grogan James F Hainfeld 《Applied immunohistochemistry & molecular morphology》2005,13(4):371-375
Ultrasensitive bright field in situ hybridization assays using enzyme metallography (EnzMet) have been developed and validated, but little is known regarding the applicability of EnzMet for immunophenotypic detection of protein via IHC. Superior resolution via discrete metallographic deposits offers the potential for enhancing high-resolution immunophenotyping. Using high-complexity tissue microarrays (TMAs), 88 common solid tumors were evaluated by automated EnzMet (Nanoprobes and Ventana). Targets were chosen to assess the ability of EnzMet to specifically localize encoded antigens in the nucleus (estrogen receptor), cytoplasm (cytokeratins), and cytoplasmic membrane (HER2) in TMAs. Results were compared with conventional IHC diaminobenzidine (DAB) immunostaining. There was full concordance between the EnzMet and conventional IHC results. Furthermore, the EnzMet reaction products did not appreciably diffuse, were dense and sharply defined, and provided excellent high-resolution differentiation of cellular compartments in paraffin sections for the nuclear, cytoplasmic, and cell membrane-localized antigens evaluated. The higher density of elemental silver deposited during enzyme metallography permitted evaluation of core immunophenotypes at a relatively low magnification, allowing more tissue to be screened in an efficient manner. This preliminary study shows the utility of using enzyme metallography for high-resolution immunophenotyping in TMAs. 相似文献