全文获取类型
收费全文 | 2557087篇 |
免费 | 164341篇 |
国内免费 | 6516篇 |
专业分类
耳鼻咽喉 | 35903篇 |
儿科学 | 80380篇 |
妇产科学 | 70979篇 |
基础医学 | 365043篇 |
口腔科学 | 73702篇 |
临床医学 | 231296篇 |
内科学 | 488959篇 |
皮肤病学 | 55077篇 |
神经病学 | 209211篇 |
特种医学 | 96580篇 |
外国民族医学 | 782篇 |
外科学 | 372758篇 |
综合类 | 55279篇 |
现状与发展 | 7篇 |
一般理论 | 900篇 |
预防医学 | 196135篇 |
眼科学 | 58613篇 |
药学 | 189921篇 |
52篇 | |
中国医学 | 5733篇 |
肿瘤学 | 140634篇 |
出版年
2018年 | 27573篇 |
2017年 | 21641篇 |
2016年 | 23969篇 |
2015年 | 26465篇 |
2014年 | 36162篇 |
2013年 | 56346篇 |
2012年 | 75513篇 |
2011年 | 80348篇 |
2010年 | 47117篇 |
2009年 | 43444篇 |
2008年 | 75699篇 |
2007年 | 81131篇 |
2006年 | 81257篇 |
2005年 | 78874篇 |
2004年 | 75727篇 |
2003年 | 72931篇 |
2002年 | 71201篇 |
2001年 | 113995篇 |
2000年 | 118104篇 |
1999年 | 98968篇 |
1998年 | 27650篇 |
1997年 | 25079篇 |
1996年 | 24258篇 |
1995年 | 22901篇 |
1994年 | 21464篇 |
1993年 | 20018篇 |
1992年 | 76796篇 |
1991年 | 74819篇 |
1990年 | 73133篇 |
1989年 | 70393篇 |
1988年 | 65385篇 |
1987年 | 64148篇 |
1986年 | 61413篇 |
1985年 | 58543篇 |
1984年 | 43930篇 |
1983年 | 37532篇 |
1982年 | 22676篇 |
1981年 | 20363篇 |
1979年 | 41252篇 |
1978年 | 29539篇 |
1977年 | 24967篇 |
1976年 | 23550篇 |
1975年 | 25484篇 |
1974年 | 30592篇 |
1973年 | 29796篇 |
1972年 | 28106篇 |
1971年 | 26221篇 |
1970年 | 24663篇 |
1969年 | 23132篇 |
1968年 | 21927篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
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
992.
G. B. Slepchenko L. S. Anisimova V. F. Slipchenko E. V. Mikheeva N. P. Pikula 《Pharmaceutical Chemistry Journal》2005,39(3):166-168
Rapid voltammetric procedures for the determination of water-soluble vitamins C, B1, and B2, fat-soluble vitamin E (α-tocopherol acetate), and quercetin in bioactive food additives have been developed. The systematic error (i.e., correctness) of the proposed procedures was evaluated using certified reference materials and the additive recovery tests, which gave the following limiting metrological characteristics: relative error, 25 %; reproducibility, 28 %; convergence, 22 %. The full analysis time (with sample preparation) did not exceed 2 hours. Voltammetric determinations under optimum conditions can be performed in the automated regime controlled by a computer according to the specially developed software.__________Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 39, No. 3, pp. 54 – 56, March, 2005. 相似文献
993.
L. A. Trukhacheva V. I. Levina A. P. Arzamastsev N. B. Grigor'ev V. G. Granik 《Pharmaceutical Chemistry Journal》2005,39(6):296-299
The kinetics of alkaline hydrolysis of N-(5-nitro-2-thiazolyl)-2-thiophenylcarboxamide (tenonitrozole or atrican) has been studied by photometric and polarographic
techniques, and the thermodynamic parameters in the intermediate state of this process were determined. A mechanism explaining
the nitric oxide (NO) production during the hydrolytic decomposition of tenonitrozole is proposed. It is suggested that the
antiprotozoal and antimicrobial activity of this drug under anaerobic conditions is related to the formation of nitro radical
anions and NO. Under aerobic and microaerophilic conditions, the hydrolysis of tenonitrozole may lead to the formation of
a peroxynitrite anion, which is a strong cytotoxic agent.
__________
Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 39, No. 6, pp. 15 – 18, June, 2005. 相似文献
994.
Lawrence S Prince Heather I Dieperink Victor O Okoh German A Fierro-Perez Roger L Lallone 《Developmental dynamics》2005,233(2):553-561
We tested the hypothesis that innate immune signaling in utero could disrupt the structural development of the fetal lung, contributing to the pathogenesis of bronchopulmonary dysplasia. Injection of Escherichia coli lipopolysaccharide (LPS) into the amniotic fluid of E15 BALB/cJ mice increased the luminal volume density of fetal mouse lungs at embryonic day (E) 17 and E18. LPS also increased luminal volume and decreased distal lung branching in fetal mouse lung explants. This effect required NF-kappaB activation and functional Toll-Like Receptor 4. Airway branching may require fibronectin-dependent epithelial-mesenchymal interactions, representing a potential target for innate immune signaling. Anti-fibronectin antibodies and LPS both blocked distal lung branching. By immunofluorescence, fibronectin localized to the clefts between newly formed airways but was restricted to peripheral mesenchymal cells in LPS-exposed explants. These data suggest that LPS may alter the expression pattern of mesenchymal fibronectin, potentially disrupting epithelial-mesenchymal interactions and inhibiting distal airway branching and alveolarization. This mechanism may link innate immune signaling with defects in structural development of the fetal lung. 相似文献
995.
A case of esthesioneuroblastoma with an unusual clinical and radiographic presentation is reported. The presenting symptoms as well as the computed tomographic examination were compatible with a primary intracranial mass. 相似文献
996.
997.
Summary. Twenty artificial periapical lesions confined to cancellous bone were prepared at the apices of first and second mandibular molars of human cadavers. The lesions emphasized removal of the lamina dura and preparation of a 'halo' lesion surrounding the root apex, plus the addition of a simulated sclerotic border. Radiographs taken before and after creation of the lesions were scored by three examiners for detectable lesions Cross-sections of the lesions were assessed for the extent of bone destruction. Periapical lesions confined to cancellous bone were detected in 80 per cent of cases, and the presence of a sclerotic border tended to enhance visualization, although not in all cases. Intentional cortical involvement also improved detection of lesions. The anatomical features of the periapical area appear to promote the visualization of lesions which might not be detected in other locations. 相似文献
998.
999.
1000.