全文获取类型
收费全文 | 21865篇 |
免费 | 1152篇 |
国内免费 | 117篇 |
专业分类
耳鼻咽喉 | 222篇 |
儿科学 | 422篇 |
妇产科学 | 484篇 |
基础医学 | 2804篇 |
口腔科学 | 587篇 |
临床医学 | 1748篇 |
内科学 | 5937篇 |
皮肤病学 | 522篇 |
神经病学 | 1905篇 |
特种医学 | 523篇 |
外科学 | 3355篇 |
综合类 | 104篇 |
现状与发展 | 1篇 |
一般理论 | 4篇 |
预防医学 | 1601篇 |
眼科学 | 409篇 |
药学 | 1086篇 |
中国医学 | 43篇 |
肿瘤学 | 1377篇 |
出版年
2023年 | 170篇 |
2022年 | 381篇 |
2021年 | 838篇 |
2020年 | 364篇 |
2019年 | 717篇 |
2018年 | 823篇 |
2017年 | 476篇 |
2016年 | 487篇 |
2015年 | 577篇 |
2014年 | 785篇 |
2013年 | 1095篇 |
2012年 | 1772篇 |
2011年 | 1686篇 |
2010年 | 985篇 |
2009年 | 910篇 |
2008年 | 1430篇 |
2007年 | 1486篇 |
2006年 | 1379篇 |
2005年 | 1364篇 |
2004年 | 1100篇 |
2003年 | 1028篇 |
2002年 | 984篇 |
2001年 | 155篇 |
2000年 | 100篇 |
1999年 | 158篇 |
1998年 | 152篇 |
1997年 | 151篇 |
1996年 | 127篇 |
1995年 | 126篇 |
1994年 | 110篇 |
1993年 | 90篇 |
1992年 | 84篇 |
1991年 | 78篇 |
1990年 | 67篇 |
1989年 | 52篇 |
1988年 | 57篇 |
1987年 | 50篇 |
1986年 | 55篇 |
1985年 | 58篇 |
1984年 | 50篇 |
1983年 | 38篇 |
1982年 | 35篇 |
1981年 | 44篇 |
1980年 | 33篇 |
1979年 | 41篇 |
1978年 | 37篇 |
1976年 | 36篇 |
1975年 | 24篇 |
1974年 | 31篇 |
1972年 | 23篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Manuel G 《The Health service journal》1991,101(5261):15
92.
93.
94.
M. E. Nava F. R. Engelhardt 《Archives of environmental contamination and toxicology》1982,11(2):141-145
American eels,Anguilla rostrata, were exposed to crude oil by ingestion of a 10, 100, or 500 l/kg fish dose per day for five days. Depuration was followed for an additional twelve days. All oil doses caused an induction of hepatic microsomal enzymes, maximally by three days of exposure. Benzo(a)pyrene hydroxylase (BaPH) showed a dose related response, with greater induction at 100 l/kg than at the other doses. The highest dose was hepatotoxic. Cytochrome P-450 induction was dose independent, and remained induced maximally for the entire experimental period, in contrast to BaPH which declined in activity. Reaction optimum for BaPH was at pH 7.5 and 27°C. A study of tissue distribution showed the liver to account for nearly all BaPH activity. A significant increase in the protein content of the hepatic postmitochondrial fraction of oil-exposed fish was also observed. 相似文献
95.
Pharmacodynamic evaluation of the epidermal growth factor receptor inhibitor OSI-774 in human epidermis of cancer patients. 总被引:11,自引:0,他引:11
Shazli N Malik Lillian L Siu Eric K Rowinsky Linda deGraffenried Lisa A Hammond Jinee Rizzo Sarah Bacus Michael G Brattain Jeffrey I Kreisberg Manuel Hidalgo 《Clinical cancer research》2003,9(7):2478-2486
BACKGROUND: OSI-774 is an inhibitor of the epidermal growth factor receptor tyrosine kinase (EGFR-TK) currently in clinical development. In preclinical models, the antitumor activity of OSI-774 was directly related to its ability to inhibit the EGFR-TK. On the basis of these data, we hypothesized that inhibition of the EGFR-TK will be required for this agent to be effective in the clinic. This study evaluated the pharmacodynamic effects of OSI-774 in normal skin tissues collected from patients treated with the agent in a Phase I study. METHODS: Patients with advanced cancer who were treated in a Phase I study of OSI-774 underwent a biopsy of normal skin epidermis at baseline and after the last dose of drug in the first course of treatment. The expression and activation of the EGFR, downstream signaling extracytoplasmatic-regulated kinase (Erk), and cell cycle regulator p27 were determined in paraffin-embedded skin tissues using an immunohistochemical method (IHC). The IHC data were analyzed using both a semiquantitative scoring system and an automatic absorbance quantitative IHC method. The number of cells with nuclear staining of p27 per 500 cells was determined. Plasma samples were collected to quantitate OSI-774 plasma concentrations. RESULTS: A total of 56 skin specimens was collected from 28 patients treated with OSI-774 at doses ranging from 25 to 200 mg/day. There was a significant decrease in phospho-EGFR (Tyr 1173) expression as determined semiquantitatively with OSI-774 treatment [2.75 +/- 0.51 (mean +/- SD) pretreatment versus 2.36 +/- 0.76 after treatment, pair comparison P = 0.01]. The quantitative ratio [(phopho-EGFR/EGFR) x 100] of phospho-EGFR (Tyr1173) decreased from 64.16 +/- 36.58 pretreatment to 48.87 +/- 35.37 post-treatment (pair comparison, P = 0.02). No significant differences were observed in phospho-Erk (Thr202/Tyr204) expression. The mean number of cells with nuclear staining for p27 increased from 185 +/- 101 (mean +/- SD) pretreatment to 253 +/- 111 post-treatment (pair comparison P = 0.02). A total of 12 (42.8%), 7 (25%), and 14 (50%) patients had >25% variation in the ratio of phospho-EGFR (Tyr1173), phospho-Erk (Thr202/Tyr204), and p27 expression, respectively. Only changes in p27 expression were related to the administered dose of OSI-774. CONCLUSIONS: OSI-774 exerted pharmacodynamic effects in skin tissues of 30-50% of patients treated with the agent. Up-regulation of p27, which is a downstream effect of EGFR inhibition, was dose related. Although there was a significant decrement in phospho-EGFR (Tyr1173), it was not related to the administered dose of OSI-774. On the basis of these findings and the relatively simple and reliable method to measure p27 expression, this biomarker appears to be the most promising and is being evaluated in Phase II studies as a predictor of clinical outcome. 相似文献
96.
Andrés Redondo Sánchez Javier de Castro Carpeño Manuel González Barón 《Clinical & translational oncology》2003,5(5):239-248
Esophageal cancer has a dismal prognosis and the surgical treatment only cures a small percentage of patients. The survival achieved by traditional surgical procedures is being improved with extended resections, but at the cost of greater morbidity. Concurrent radiochemotherapy can obtain results similar to those of surgery. Nowadays, locally advanced esophageal cancer should have a multimodal approach, because neoadjuvant chemotherapy, with or without radiotherapy, has demonstrated to improve the survival of chemosensitive patients. Recently, the role of hyperfractionated radiotherapy and new drugs such as paclitaxel, docetaxel and irinotecan in neoadjuvant treatment is being evaluated. 相似文献
97.
98.
Vidal-Sanz M Lafuente M Sobrado-Calvo P Selles-Navarro I Rodriguez E Mayor-Torroglosa S Villegas-Perez MP 《Neurotoxicity research》2000,2(2-3):215-227
In adult Sprague-Dawley rats, retinal ganglion cell survival was investigated after intraorbital optic nerve section and after transient ischemia of the retina induced by elevation of the intraocular pressure or by selective ligature of the ophthalmic vessels. The thickness of the inner nuclear and inner plexiform layers was also assessed after transient periods (120 min) of retinal ischemia induced by selective ligature of the ophthalmic vessels. In addition, we have also investigated the neuroprotective effects of different substances in these paradigms. The intraocular injection of brain-derived neurotrophic factor increased RGC survival after retinal ischemia induced by elevation of the intraocular pressure or by selective ligature of the ophthalmic vessels. The caspase-inhibitor Z-DEVD increased retinal ganglion cell survival after optic nerve section and also after 90 min of retinal ischemia induced by selective ligature of the ophthalmic vessels. The peptide Bcl-2 did not increase retinal ganglion cell survival after optic nerve section but increased retinal ganglion cell survival after 60 or 90 min of retinal ischemia induced by selective ligature of the ophthalmic vessels. Finally, BDNF, nifedipine, naloxone and bcl-2 prevented in part the decrease in thickness of the inner nuclear layer and inner plexiform layer induced by selective ligature of the ophthalmic vessels. Our results suggest that retinal ganglion cell loss induced by different types of injury, may be prevented by substances with neuroprotective effects, by altering steps of the cascade of events leading to cell death. 相似文献
99.
Javier Sastre Eugenio Marcuello Bartomeu Masutti Matilde Navarro Silvia Gil Antonio Antón Albert Abad Enrique Aranda Joan Maurel Manuel Valladares Inmaculada Maestu Alfredo Carrato José María Vicent Eduardo Díaz-Rubio 《Journal of clinical oncology》2005,23(15):3545-3551
PURPOSE: Elderly patients constitute a subpopulation with special characteristics that differ from those of the nonelderly and have been underrepresented in clinical trials. This study was performed to determine the efficacy and safety of irinotecan (CPT-11) in combination with fluorouracil (FU) administered as a 48-hour continuous infusion twice a month in elderly patients. PATIENTS AND METHODS: Patients > or = 72 years old with metastatic colorectal cancer, Eastern Cooperative Oncology Group performance status of 0 to 1, no geriatric syndromes, and no prior treatment were treated every 2 weeks with CPT-11 180 mg/m2 plus FU 3,000 mg/m2 in a 48-hour continuous infusion. RESULTS: By intent-to-treat analysis, in 85 assessable patients, the objective response rate was 35% (95% CI, 25% to 46%), and stable disease was 33% (95% CI, 23% to 44%). Median time to progression was 8.0 months (95% CI, 6.0 to 10.0 months), and median overall survival time was 15.3 months (95% CI, 13.8 to 16.9 months). Toxicity was moderate. Grade 3 and 4 neutropenia, diarrhea, and asthenia were observed in 21%, 17%, and 13% of patients, respectively. Only one case of neutropenic fever occurred. There were two toxic deaths, one was a result of grade 4 diarrhea and acute kidney failure, and the other was a result of massive intestinal hemorrhage in the first cycle. The study of prognostic factors did not reveal any predictive factor of response. Response to treatment and baseline lactate dehydrogenase were the main factors conditioning progression-free and overall survival. CONCLUSION: Twice a month continuous-infusion CPT-11 combined with FU is a valid therapeutic alternative for elderly patients in good general condition. 相似文献
100.
Marina Gonzalez-Ramirez Rocio Sanchez-Carrera Angela Cejudo-Lopez Mauricio Lozano-Navarrete Elena Salamero Snchez-Gabriel M. Alfonso Torres-Bengoa Manuel Segura-Balbuena Maria J. Sanchez-Cordero Mercedes Barroso-Vazquez Francisco J. Perez-Barba Ana M. Troncoso M. Carmen Garcia-Parrilla Ana B. Cerezo 《Nutrients》2022,14(10)
Promoting a healthy diet is a relevant strategy for preventing non-communicable diseases. This study aims to evaluate the impact of an innovative tool, the SAlBi educa nutrition app, in primary healthcare dietary counseling to improve dietary profiles as well as adherence to the Mediterranean diet. A multi-center randomized control trial comprising 104 participants was performed. Both control (n = 49) and intervention (n = 55) groups attended four once-weekly sessions focusing on healthy eating habits and physical activity, over one month. As well as attending the meetings, the intervention group used the app, which provides self-monitoring and tailored dietary advice based on the Mediterranean diet model. In a second intervention (one arm trial), the potential of SAlBi educa was evaluated for three months during the COVID-19 pandemic. At 4 weeks, the intervention group had significantly increased their carbohydrate intake (7.7% (95% CI: 0.16 to 15.2)) and decreased their total fat intake (−5.7% (95% CI: −10.4 to −1.15)) compared to the control group. Significant differences were also found for carbohydrates (3.5% (95% CI: −1.0 to 5.8)), total fats (−5.9% (95% CI: −8.9 to −3.0)), fruits and vegetables (266.3 g/day (95% CI: 130.0 to 402.6)), legumes (7.7g/day (95% CI: 0.2 to 15.1)), starchy foods (36.4 g/day (95% CI: 1.1 to 71.7)), red meat (−17.5 g/day (95% CI: −34.0 to −1.1)), and processed meat (−6.6 g/day (95% CI: −13.1 to −0.1)) intakes during the COVID-19 pandemic. SAlBi educa is a useful tool to support nutrition counseling in primary healthcare, including in special situations such as the COVID-19 pandemic. Trial registration: ISRCTN57186362. 相似文献