全文获取类型
收费全文 | 10502篇 |
免费 | 623篇 |
国内免费 | 49篇 |
专业分类
耳鼻咽喉 | 124篇 |
儿科学 | 268篇 |
妇产科学 | 256篇 |
基础医学 | 1493篇 |
口腔科学 | 157篇 |
临床医学 | 974篇 |
内科学 | 2500篇 |
皮肤病学 | 233篇 |
神经病学 | 947篇 |
特种医学 | 256篇 |
外科学 | 1252篇 |
综合类 | 185篇 |
一般理论 | 12篇 |
预防医学 | 719篇 |
眼科学 | 239篇 |
药学 | 889篇 |
中国医学 | 26篇 |
肿瘤学 | 644篇 |
出版年
2023年 | 57篇 |
2022年 | 117篇 |
2021年 | 231篇 |
2020年 | 107篇 |
2019年 | 155篇 |
2018年 | 203篇 |
2017年 | 161篇 |
2016年 | 197篇 |
2015年 | 230篇 |
2014年 | 299篇 |
2013年 | 418篇 |
2012年 | 583篇 |
2011年 | 604篇 |
2010年 | 305篇 |
2009年 | 352篇 |
2008年 | 565篇 |
2007年 | 608篇 |
2006年 | 559篇 |
2005年 | 559篇 |
2004年 | 554篇 |
2003年 | 490篇 |
2002年 | 505篇 |
2001年 | 227篇 |
2000年 | 193篇 |
1999年 | 178篇 |
1998年 | 130篇 |
1997年 | 107篇 |
1996年 | 86篇 |
1995年 | 77篇 |
1994年 | 86篇 |
1993年 | 89篇 |
1992年 | 146篇 |
1991年 | 151篇 |
1990年 | 115篇 |
1989年 | 139篇 |
1988年 | 127篇 |
1987年 | 115篇 |
1986年 | 116篇 |
1985年 | 88篇 |
1984年 | 88篇 |
1983年 | 78篇 |
1982年 | 78篇 |
1981年 | 61篇 |
1980年 | 58篇 |
1979年 | 50篇 |
1978年 | 49篇 |
1977年 | 47篇 |
1976年 | 45篇 |
1975年 | 65篇 |
1971年 | 45篇 |
排序方式: 共有10000条查询结果,搜索用时 22 毫秒
61.
Phase I trial and pharmacokinetic study of BMS-247550, an epothilone B analog, administered intravenously on a daily schedule for five days. 总被引:4,自引:0,他引:4
Jame Abraham Manish Agrawal Susan Bakke Ann Rutt Maureen Edgerly Frank M Balis Brigitte Widemann Louis Davis Bharat Damle Daryl Sonnichsen David Lebwohl Susan Bates Herb Kotz Tito Fojo 《Journal of clinical oncology》2003,21(9):1866-1873
PURPOSE: The epothilones are a novel class of nontaxane microtubule-stabilizing agents. BMS-247550 is a semisynthetic analog of the natural product epothilone B. We conducted a phase I study administering BMS-247550 as a 1-hour intravenous infusion daily for 5 consecutive days every 21 days. PATIENTS AND METHODS: Twenty-one patients received BMS-247550 without filgrastim in the first cycle. An additional six patients were enrolled at a starting dose of 8 mg/m2/d with filgrastim support. Twenty-one of the 27 patients had received prior paclitaxel, docetaxel, or both. RESULTS: One hundred seven cycles were administered to 27 patients. The maximum-tolerated dose was 6 mg/m2 of BMS-247550 administered as a 1-hour intravenous infusion daily for 5 consecutive days every 21 days. Dose-limiting toxicity at a dose of 8 mg/m2/d was neutropenia with or without filgrastim support. Nonhematologic grade 3 toxicities included fatigue (seven cycles), stomatitis (two cycles), and anorexia (one cycle). The mean terminal half-life of BMS-247550 was 16.8 +/- 6.0 hours, the volume of distribution at steady-state was 798 +/- 375 L, and the clearance was 712 +/- 247 mL/min. Objective responses were observed in patients with breast, cervical, and basal cell cancer. Reductions in CA-125 levels were noted in patients with ovarian cancer. CONCLUSION: The recommended phase II dose of BMS-247550 on the daily schedule for 5 days is 6 mg/m2/d. Neutropenia was dose limiting, but higher doses were tolerated by a large fraction of patients with filgrastim support. Peripheral neuropathy was mild, even after multiple cycles of therapy, and was not dose limiting. 相似文献
62.
63.
Murray KD Isackson PJ Eskin TA King MA Montesinos SP Abraham LA Roper SN 《The Journal of comparative neurology》2000,418(4):411-422
The expression of brain-derived neurotrophic factor and the alpha subunit of calcium/calmodulin-dependent protein kinase II mRNA in hippocampi obtained during surgical resections for intractable temporal lobe epilepsy were examined. Both calcium/calmodulin-dependent protein kinase II and brain-derived neurotrophic factor are localized heavily within the hippocampus and have been implicated in regulating hippocampal activity (Kang and Schuman [1995] Science 267:1658-1662; Suzuki [1994] Intl J Biochem 26:735-744). Also, the autocrine and paracrine actions of brain-derived neurotrophic factor within the central nervous system make it a likely candidate for mediating morphologic changes typically seen in the epileptic hippocampus. Quantitative assessments of mRNA levels in epileptic hippocampi relative to autopsy controls were made by using normalized densitometric analysis of in situ hybridization. In addition, correlations between clinical data and mRNA levels were studied. Relative to autopsy control tissue, decreased hybridization to mRNA of the alpha subunit of calcium/calmodulin-dependent protein kinase II and increased hybridization to brain-derived neurotrophic factor mRNA were found throughout the granule cells of the epileptic hippocampus. There also was a significant negative correlation between the duration of epilepsy and the expression of mRNA for brain-derived neurotrophic factor. These results are similar qualitatively to those found in animal models of epilepsy and suggest that chronic seizure activity in humans leads to persistent alterations in gene expression. Furthermore, these alterations in gene expression may play a role in the etiology of the epileptic condition. 相似文献
64.
Kamishima T Schweitzer ME Awaya H Abraham D 《Journal of magnetic resonance imaging : JMRI》2000,12(6):953-955
Because full vials of commercially available MR arthrographic contrast are expensive, we hypothesized that the small residual contrast in a "used" vial would be adequate for MR arthrography. After sterility testing and quantity analysis of the residual contrast in 28 vials, this method was successfully used in 10 patients. J. Magn. Reson. Imaging 2000;12:953-955. 相似文献
65.
A Rose S Roy V Abraham G Holmgren K George V Balraj S Abraham J Muliyil A Joseph G Kang 《Archives of disease in childhood》2006,91(2):139-141
AIMS: To evaluate the efficacy and acceptability of solar irradiation in the prevention of diarrhoeal morbidity in children under 5 years of age, in an urban slum in Vellore, Tamil Nadu. METHODS: A total of 100 children were assigned to receive drinking water that had been subjected to solar disinfection in polyethylene terephthalate bottles. One hundred age and sex matched controls were also selected. Both groups were followed by weekly home visits for a period of six months for any diarrhoeal morbidity. At the end of the follow up period, the acceptability of the intervention was assessed by interviews, questionnaires, and focus group discussions. RESULTS: There was significant reduction in the incidence, duration, and severity of diarrhoea in children receiving solar disinfected water, despite 86% of the children drinking water other than that treated by the intervention. The incidence of diarrhoea in the intervention group was 1.7 per child-year, and among controls 2.7 per child-year, with an incidence rate ratio of 0.64 (95% CI -0.48 to 0.86). The risk of diarrhoea was reduced by 40% by using solar disinfection. In qualitative evaluation of acceptability, most women felt that solar disinfection was a feasible and sustainable method of disinfecting water. CONCLUSIONS: Solar disinfection of water is an inexpensive, effective, and acceptable method of increasing water safety in a resource limited environment, and can significantly decrease diarrhoeal morbidity in children. 相似文献
66.
67.
WBG Macdonald AP Patrikeos RI Thompson BD Adler AA Van Der Schaaf 《Journal of Medical Imaging and Radiation Oncology》2005,49(1):32-38
The present study compared the accuracy of ventilation perfusion scintigraphy (VQS) and CT pulmonary angiography (CTPA) for the diagnosis of pulmonary embolism. This was a prospective observational study of 112 patients with suspected pulmonary embolism (PE) who could be studied with both investigations within 24 h. Results were compared to final diagnosis at completion of 6-month follow up, using receiver operating characteristic (ROC) analysis. Pulmonary embolism was diagnosed in 27 referred patients (24%). The sensitivity and specificity of VQS and CTPA were similar to that reported from the literature. A normal VQ scan had the highest negative predictive value (100%), while a high-probability VQ scan had the highest positive predictive value (92%). There was no overall difference (area under the ROC curve (AUC)) between VQS (AUC (95% CI) = 0.82 (0.75,0.89)) and CTPA (AUC = 0.88 (0.81,0.94)) for the diagnosis of PE. Among patients with abnormal chest X-rays, CTPA (AUC 0.90 (0.83,0.97)) appeared somewhat better than VQS (AUC 0.78 (0.68,0.88)) but this difference did not reach statistical significance. In this instance, CTPA is at least as accurate as VQS and may provide an opportunity to make alternative diagnoses. 相似文献
68.
In recent studies, riddelliine, a pyrrolizidine alkaloid, was found to increase rates of replication and apoptosis and induce hemangiosarcoma in the liver of rats and mice. To analyze DNA replication and apoptosis data taken from the same animals, we have developed a predictive mathematical model for describing BrdU labeling and apoptotic processes. The model allows the incorporation of simple diurnal patterns in cellular kinetics and is applied to data on hepatocytes and endothelial cells taken from riddelliine exposed rats. Predictions from the model were used with multivariable nonlinear regression techniques to estimate replication and apoptotic rate constants for both cell types and all treatment groups. Hypothesis tests were used with the predicted rates to separate the competing effects of riddelliine on replication and apoptosis of hepatocytes and endothelial cells as well as compare replication rates between cell types. That estimated replication rates were found to be significantly higher for endothelial cells supports the supposition of induction of hemangiosarcoma by riddelliine in the liver. 相似文献
69.
70.
Andra Araujo Brando Weimar Kunz Sebba Barroso Audes Feitosa Eduardo Costa Duarte Barbosa Roberto Dischinger Miranda Priscila Valverde de Oliveira Vitorino Roberto Pozzan Lucio Paulo Ribeiro Abraham Epelman Giovanni Alves Saraiva Fabio Serra Silveira Antnio Almeida Braga Marco Mota Gomes 《Arquivos brasileiros de cardiologia》2022,119(2):353