全文获取类型
收费全文 | 32375篇 |
免费 | 2091篇 |
国内免费 | 104篇 |
专业分类
耳鼻咽喉 | 491篇 |
儿科学 | 780篇 |
妇产科学 | 372篇 |
基础医学 | 4053篇 |
口腔科学 | 493篇 |
临床医学 | 3268篇 |
内科学 | 7642篇 |
皮肤病学 | 209篇 |
神经病学 | 3276篇 |
特种医学 | 1344篇 |
外科学 | 5346篇 |
综合类 | 321篇 |
一般理论 | 72篇 |
预防医学 | 2226篇 |
眼科学 | 417篇 |
药学 | 1951篇 |
中国医学 | 22篇 |
肿瘤学 | 2287篇 |
出版年
2023年 | 162篇 |
2022年 | 282篇 |
2021年 | 731篇 |
2020年 | 409篇 |
2019年 | 720篇 |
2018年 | 862篇 |
2017年 | 593篇 |
2016年 | 679篇 |
2015年 | 777篇 |
2014年 | 1132篇 |
2013年 | 1436篇 |
2012年 | 2353篇 |
2011年 | 2415篇 |
2010年 | 1389篇 |
2009年 | 1137篇 |
2008年 | 2176篇 |
2007年 | 2268篇 |
2006年 | 2173篇 |
2005年 | 2171篇 |
2004年 | 1953篇 |
2003年 | 1858篇 |
2002年 | 1797篇 |
2001年 | 322篇 |
2000年 | 248篇 |
1999年 | 319篇 |
1998年 | 367篇 |
1997年 | 292篇 |
1996年 | 244篇 |
1995年 | 245篇 |
1994年 | 204篇 |
1993年 | 187篇 |
1992年 | 193篇 |
1991年 | 195篇 |
1990年 | 172篇 |
1989年 | 146篇 |
1988年 | 144篇 |
1987年 | 133篇 |
1986年 | 129篇 |
1985年 | 135篇 |
1984年 | 168篇 |
1983年 | 131篇 |
1982年 | 138篇 |
1981年 | 127篇 |
1980年 | 97篇 |
1979年 | 72篇 |
1978年 | 74篇 |
1977年 | 58篇 |
1976年 | 48篇 |
1974年 | 47篇 |
1971年 | 43篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
Anthony Spirito Larry Brown James Overholser Gregory Fritz Andrea Bond 《Death Studies》1991,15(3):269-280
The assessment of the medical lethality and intent of suicide attempts has been considered an important area of research for those interested in suicide. The current study examined the usefulness of the Risk-Rescue Rating Scale with 109 adolescent suicide attempters and found a restricted range of variability, which, in turn, resulted in poor interrater reliability on a number of items. Results suggest that the Risk-Rescue Rating Scale is of limited usefulness with adolescents, and alternative approaches to assessing lethality and suicidal intent with this age group are discussed. 相似文献
6.
Najat C Daw Wayne L Furman Clinton F Stewart Lisa C Iacono Mark Krailo Mark L Bernstein Janet E Dancey Rose Anne Speights Susan M Blaney James M Croop Gregory H Reaman Peter C Adamson 《Journal of clinical oncology》2005,23(25):6172-6180
PURPOSE: Epidermal growth factor receptor is expressed in pediatric malignant solid tumors. We conducted a phase I trial of gefitinib, an epidermal growth factor receptor tyrosine kinase inhibitor, in children with refractory solid tumors. PATIENTS AND METHODS: Gefitinib (150, 300, 400, or 500 mg/m2) was administered orally to cohorts of three to six patients once daily continuously until disease progression or significant toxicity. Pharmacokinetic studies were performed during course one (day 1 through 28). RESULTS: Of the 25 enrolled patients, 19 (median age, 15 years) were fully evaluable for toxicity and received 54 courses. Dose-limiting toxicity was rash in two patients treated with 500 mg/m2 and elevated ALT and AST in one patient treated with 400 mg/m2. The maximum-tolerated dose was 400 mg/m2/d. The most frequent non-dose-limiting toxicities were grade 1 or 2 dry skin, anemia, diarrhea, nausea, and vomiting. One patient with Ewing's sarcoma had a partial response. Disease stabilized for 8 to > or = 60 weeks in two patients with Wilms' tumor and two with brainstem glioma (one exophytic). At 400 mg/m2, the median peak gefitinib plasma concentration was 2.2 microg/mL (range, 1.2 to 3.6 microg/mL) and occurred at a median of 2.3 hours (range, 2.0 to 8.3 hours) after drug administration. The median apparent clearance and median half-life were 14.8 L/h/m2 (range, 3.8 to 24.8 L/h/m2) and 11.7 hours (range, 5.6 to 22.8 hours), respectively. Gefitinib systemic exposures were comparable with those associated with antitumor activity in adults. CONCLUSION: Oral gefitinib is well tolerated in children. Development of the drug in combination with cytotoxic chemotherapy will be pursued. 相似文献
7.
Charles H Henry Judith A Whittum-Hudson Gregory T Tull Larry M Wolford 《Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics》2007,104(1):e22-e26
OBJECTIVE: The objective of this study was to determine if temporomandibular joint (TMJ) samples positive for Chlamydia trachomatis have a greater presence of tumor necrosis factor-alpha (TNFalpha) or interleukin-6 (IL-6) when compared with Chlamydia-negative samples. STUDY DESIGN: Posterior bilaminar tissue samples removed during TMJ surgery from 70 patients were evaluated. Cryosections were stained using monoclonal antibody that identifies C. trachomatis. The presence of IL-6 and TNFalpha were evaluated by immunostaining in 15 samples positive and in 25 samples negative for the presence of C. trachomatis. RESULTS: Of the 70 TMJ samples, 32 (46%) were positive for C. trachomatis. In 15 samples positive for C. trachomatis, 10 (67%) were positive for TNFalpha and 7 (47%) for IL-6. In 25 samples negative for C. trachomatis, only 4 (16%) were positive for TNFalpha and only 2 (8%) for IL-6. Differences in C. trachomatis-positive samples versus negative were significant for both TNFalpha (P < .002) and IL-6 (P < .008). CONCLUSION: The presence of C. trachomatis in the TMJ is associated with a significantly increased presence of TNFalpha and IL-6. 相似文献
8.
9.
Davangere P Devanand Christian G Habeck Matthias H Tabert Nikolaos Scarmeas Gregory H Pelton James R Moeller Brett D Mensh Tyler Tarabula Ronald L Van Heertum Yaakov Stern 《Neuropsychopharmacology》2006,31(6):1327-1334
Temporoparietal and posterior cingulate metabolism deficits characterize patients with Alzheimer's disease (AD). A H(2)(15)O resting PET scan covariance pattern, derived by using multivariate techniques, was previously shown to discriminate 17 mild AD patients from 16 healthy controls. This AD covariance pattern revealed hypoperfusion in bilateral inferior parietal lobule and cingulate; and left middle frontal, inferior frontal, precentral, and supramarginal gyri. The AD pattern also revealed hyperperfusion in bilateral insula, lingual gyri, and cuneus; left fusiform and superior occipital gyri; and right parahippocampal gyrus and pulvinar. In an independent sample of 23 outpatients with mild cognitive impairment (MCI) followed at 6-month intervals, the AD pattern score was evaluated as a predictor of cognitive decline. In this MCI sample, an H2(15)O resting PET scan was carried out at baseline. Mean duration of follow-up was 48.8 (SD 15.5) months, during which time six of 23 MCI patients converted to AD. In generalized estimating equations (GEE) analyses, controlling for age, sex, education, and baseline neuropsychological scores, increased AD pattern score was associated with greater decline in each neuropsychological test score over time (Mini Mental State Exam, Selective Reminding Test delayed recall, Animal Naming, WAIS-R digit symbol; Ps<0.01-0.001). In summary, a resting PET covariance pattern previously reported to discriminate AD patients from control subjects was applied prospectively to an independent sample of MCI patients and found to predict cognitive decline. Independent replication in larger samples is needed before clinical application can be considered. 相似文献
10.