全文获取类型
收费全文 | 2535篇 |
免费 | 137篇 |
国内免费 | 16篇 |
专业分类
耳鼻咽喉 | 25篇 |
儿科学 | 62篇 |
妇产科学 | 81篇 |
基础医学 | 310篇 |
口腔科学 | 26篇 |
临床医学 | 148篇 |
内科学 | 799篇 |
皮肤病学 | 31篇 |
神经病学 | 223篇 |
特种医学 | 54篇 |
外科学 | 381篇 |
综合类 | 5篇 |
预防医学 | 144篇 |
眼科学 | 19篇 |
药学 | 162篇 |
中国医学 | 4篇 |
肿瘤学 | 214篇 |
出版年
2023年 | 17篇 |
2022年 | 28篇 |
2021年 | 56篇 |
2020年 | 36篇 |
2019年 | 51篇 |
2018年 | 56篇 |
2017年 | 62篇 |
2016年 | 61篇 |
2015年 | 79篇 |
2014年 | 94篇 |
2013年 | 114篇 |
2012年 | 169篇 |
2011年 | 161篇 |
2010年 | 106篇 |
2009年 | 76篇 |
2008年 | 151篇 |
2007年 | 150篇 |
2006年 | 124篇 |
2005年 | 140篇 |
2004年 | 139篇 |
2003年 | 111篇 |
2002年 | 104篇 |
2001年 | 66篇 |
2000年 | 59篇 |
1999年 | 44篇 |
1998年 | 25篇 |
1997年 | 22篇 |
1996年 | 24篇 |
1995年 | 12篇 |
1994年 | 9篇 |
1993年 | 20篇 |
1992年 | 42篇 |
1991年 | 27篇 |
1990年 | 18篇 |
1989年 | 22篇 |
1988年 | 23篇 |
1987年 | 13篇 |
1986年 | 15篇 |
1985年 | 22篇 |
1984年 | 9篇 |
1983年 | 11篇 |
1982年 | 8篇 |
1981年 | 7篇 |
1980年 | 10篇 |
1979年 | 20篇 |
1978年 | 10篇 |
1977年 | 12篇 |
1976年 | 7篇 |
1975年 | 7篇 |
1972年 | 7篇 |
排序方式: 共有2688条查询结果,搜索用时 15 毫秒
101.
Barbaro G Grisorio B Fruttaldo L Bacca D Babudieri S Torre D Francavilla R Rizzo G Belloni G Lucchini A Annese M Matarazzo F Hazra C Barbarini G 《BioDrugs : clinical immunotherapeutics, biopharmaceuticals and gene therapy》2003,17(6):433-439
Background: The differential tolerability profile of various interferon (IFN)-α preparations used in combination with ribavirin for the treatment of chronic hepatitis C needs to be elucidated. Approximately 8% of patients receiving recombinant IFNα-2b plus ribavirin discontinue treatment because of adverse events. Human leucocyte IFNα is deemed to have a better safety profile than recombinant IFNα. We therefore compared the safety profile and efficacy of ribavirin combined with leucocyte IFNα or with recombinant IFNα-2b in treatment-naive patients with chronic hepatitis C. Study design: We randomised 423 patients to either leucocyte IFNα 3MU three times weekly plus ribavirin (210 patients) or the same dose of recombinant IFNα-2b plus ribavirin (213 patients). Patients were treated for 24 weeks and followed-up for a further 48 weeks. The primary endpoint was the safety profile of the two therapies; the secondary endpoint was the rate of sustained response. Results: In patients receiving leucocyte IFNα, the total number of adverse events was lower than in the group receiving recombinant IFNα (259 vs 441 patients), and the percentage of patients discontinuing treatment because of adverse events or laboratory abnormalities was significantly reduced (4% vs 11%; p = 0.013). Sustained response was observed in 47% of patients receiving leucocyte IFNα plus ribavirin and in 44% of patients receiving IFNα-2b plus ribavirin. Conclusions: Both therapeutic regimens were effective in inducing a sustained response in naive patients. However, the safety profile of leucocyte IFNα plus ribavirin was more favourable than that observed with the administration of recombinant IFNα-2b plus ribavirin, suggesting that leucocyte IFNα may be an alternative option in patients with reduced tolerability to other IFNs. 相似文献
102.
Inhibition of SRC expression and activity inhibits tumor progression and metastasis of human pancreatic adenocarcinoma cells in an orthotopic nude mouse model 下载免费PDF全文
Trevino JG Summy JM Lesslie DP Parikh NU Hong DS Lee FY Donato NJ Abbruzzese JL Baker CH Gallick GE 《The American journal of pathology》2006,168(3):962-972
The nonreceptor protein tyrosine kinase Src is overexpressed in 70% of pancreatic adenocarcinomas. Here, we describe the effect of molecular and pharmacological down-regulation of Src on incidence, growth, and metastasis of pancreatic tumor cells in an orthotopic model. Src expression in L3.6pl human pancreatic tumor cells was reduced by stable expression of a plasmid encoding small interfering RNA (siRNA) to c-src. In stable siRNA clones, Src expression was reduced >80%, with no change in expression of the related kinases c-Yes and c-Lyn, and proliferation rates were similar in all clones. Phosphorylation of Akt and p44/42 Erk mitogen-activated protein kinase and production of VEGF and IL-8 in culture supernatants were also reduced (P < 0.005). On orthotopic implantation of varying cell numbers into nude mice, tumor incidence was unchanged; however, in the siRNA clones, large tumors failed to develop, and incidence of metastasis was significantly reduced, suggesting that c-Src activity is critical to tumor progression. To examine this possibility further, animals bearing established wild-type tumors were treated with the Src/Abl-selective inhibitor BMS-354825 (dasatinib). Tumor size was decreased, and incidence of metastases was significantly reduced in treated mice compared with controls. These results demonstrate that Src activation contributes to pancreatic tumor progression in this model, offering Src as a candidate for targeted therapy. 相似文献
103.
The constitutional gain-of-function variant p.Glu1099Lys in NSD2 is associated with a novel syndrome
Bernt Popp Melanie Brugger Sibylle Poschmann Tobias Bartolomaeus Maximilian Radtke Julia Hentschel Nataliya Di Donato Andreas Rump Janina Gburek-Augustat Elisabeth Graf Matias Wagner Ina Sorge Johannes R Lemke Thomas Meitinger Rami Abou Jamra Vincent Strehlow Theresa Brunet 《Clinical genetics》2023,103(2):226-230
104.
Salvatore Gizzo Marco Noventa Simone Fagherazzi Laura Lamparelli Emanuele Ancona Stefania Di Gangi Carlo Saccardi Donato D’Antona Giovanni Battista Nardelli 《Archives of gynecology and obstetrics》2014,290(1):21-34
Purpose
In modern obstetrics, different pharmacological and non-pharmacological options allow to obtain pain relief during labour, one of the most important goals in women satisfaction about medical care. The aim of this review is to compare all the analgesia administration schemes in terms of effectiveness in pain relief, length of labour, mode of delivery, side effects and neonatal outcomes.Methods
A systematic literature search was conducted in electronic databases in the interval time between January 1999 and March 2013. Key search terms included: “labour analgesia”, “epidural anaesthesia during labour” (excluding anaesthesia for Caesarean section), “epidural analgesia and labour outcome” and “intra-thecal analgesia”.Results
10,331 patients were analysed: 5,578 patients underwent Epidural-Analgesia, 259 patients spinal analgesia, 2,724 combined spinal epidural analgesia, 322 continuous epidural infusion (CEI), 168 intermittent epidural bolus, 684 patient-controlled infusion epidural analgesia and 152 intra-venous patient-controlled epidural analgesia. We also considered 341 women who underwent patient-controlled infusion epidural analgesia in association with CEI and 103 patients who underwent patient-controlled infusion epidural analgesia in association with automatic mandatory bolus.Conclusion
No significant differences occurred among all the available administration schemes of neuraxial analgesia. In absence of obstetrical contraindication, neuraxial analgesia has to be considered as the gold standard in obtaining maternal pain relief during labour. The options available in the administration of analgesia should be known and evaluated together by both gynaecologists and anaesthesiologists to choose the best personalized scheme and obtain the best women satisfaction. Since it is difficult to identify comparable circumstances during labour, it is complicate to standardize drugs schemes and their combinations. 相似文献105.
I. Rodeiro M.T. Donato N. Jimnez G. Garrido R. Delgado M.J. Gmez-Lechn 《Food and chemical toxicology》2007,45(12):2506-2512
Vimang is an aqueous extract from stem bark of Mangifera indica L. (Mango) with pharmacological properties. It is a mixture of polyphenols (as main components), terpenoids, steroids, fatty acids and microelements. In the present work we studied the cytotoxic effects of Vimang on rat hepatocytes, possible interactions of the extract with drug-metabolizing enzymes and its effects on GSH levels and lipid peroxidation. No cytotoxic effects were observed after 24 h exposure to Vimang of up to 1000 μg/mL, while a moderate cytotoxicity was observed after 48 and 72 h of exposure at higher concentrations (500 and 1000 μg/mL). The effect of the extract (50–400 μg/mL) on several P450 isozymes was evaluated. Exposure of hepatocytes to Vimang at concentrations of up to 100 μg/mL produced a significant reduction (60%) in 7-methoxyresorufin-O-demethylase (MROD; CYP1A2) activity, an increase (50%) in 7-penthoxyresorufin-O-depentylase (PROD; CYP2B1) activity, while no significant effect was observed with other isozymes. To our knowledge, this is the first report regarding the modulation of the activity of the P450 system by an extract of Mangifera indica L. The antioxidant properties of Vimang were also evaluated in t-butyl-hydroperoxide-treated hepatocytes. A 36-h pre-treatment of cells with Vimang (25–200 μg/mL) strongly inhibited the decrease of GSH levels and lipid peroxidation induced by t-butyl-hydroperoxide dose- and time-dependently. 相似文献
106.
H N Nguyen B U Sevin H E Averette J Perras R Ramos M Penalver D Donato 《Gynecologic oncology》1991,42(2):165-177
Even though progestin is commonly added to many chemotherapy regimens in the treatment of uterine cancers, its role is still unproven. Since progestin is antiproliferative, its tendency to arrest cells in G1 phase may interfere with cytotoxic mechanisms. The ATP chemosensitivity assay and flow cytometry were used to study the effects of a progestational compound such as Provera on three single agents and four drug combinations. Uterine cancer cell lines included progesterone-receptor (PR)-positive AE7 and ECC1 and PR-negative HEC1A, HEC1B, AN3, and SKUT1B. Provera selectively affected only PR-positive cell lines. It imposed an antiproliferative effect on drug-induced cell-cycle perturbations by reducing G2 and S blocks and minimizing G1 depletion. When using IC50s (concentrations required for 50% growth inhibition) of 0.5 as a cutoff for drug sensitivity and resistance, Provera significantly improved the IC50s of the drug-resistant subgroup from 1.95 +/- 0.36 to 0.71 +/- 0.19 (P = 0.009) but not those of the drug-sensitive subgroup (P = 0.13). In summary, Provera appeared to work independently from cytotoxic mechanisms. Its improvement of cytotoxicity was most pronounced in resistant cell lines bearing progesterone receptors. 相似文献
107.
Determination of hormonal response in uterine cancer cell lines by the ATP bioluminescence assay and flow cytometry. 总被引:1,自引:0,他引:1
H N Nguyen B U Sevin H E Averette W Voigt J Perras R Angioli R Ramos D Donato M Penalver 《Gynecologic oncology》1992,46(1):55-61
Although progesterone receptor status has been shown to correlate with response to hormonal therapy, not all progesterone receptor-positive patients respond to this treatment and additional biologic assays are needed to help better predict clinical response to hormonal therapy. This study explored the potential of the ATP bioluminescence assay and flow cytometry as biological assays of hormonal response. Five uterine cancer cell lines were used: AE7, ECC-1, HEC1A, AN3, and SKUT1B. Cells were exposed to Provera or tamoxifen at 0.1, 0.2, 0.5, 1, 2, and 5X (X equal to peak plasma concentrations: 1.0 micrograms/ml Provera and 0.1 micrograms/ml tamoxifen). For correlation, estrogen and progesterone receptors were determined by the standard dextran-coated charcoal method. Only AE7 and ECC-1 were positive for progesterone receptors (501 fmol/mg AE7, 194 fmol/mg ECC-1) and the rest were negative (less than 8 fmol/mg). Tamoxifen exerted no inhibition to the above cell lines. Meanwhile, Provera exerted dose-response inhibition on both AE7 and ECC-1 cell lines. The effects of accumulation of G0-G1 phase and reduction of S, G2 cells (P less than 0.05), but not on the HEC1A cell line (P = 0.4). These changes confirmed the antiproliferative property of Provera. Further studies are needed to establish the role of the ATP bioluminescence assay and flow cytometry as biological assays of hormonal response. 相似文献
108.
Ferrali M Bambagioni S Ceccanti A Donati D Giorgi G Fontani M Laschi F Zanello P Casolaro M Pietrangelo A 《Journal of medicinal chemistry》2002,45(26):5776-5785
Increasing evidence suggests that iron plays an important role in tissue damage both during chronic iron overload diseases (i.e., hemochromatosis) and when, in the absence of actual tissue iron overload, iron is delocalized from specific carriers or intracellular sites (inflammation, neurodegenerative diseases, postischaemic reperfusion, xenobiotic intoxications, etc.). In the present work, we appropriately modified an iron chelator of the hydroxychromene family in order to obtain a tridentate chelator that would inactivate the iron redox cycle after its complexation, with a view to using this molecule in human therapy and/or in disease prevention. We synthesized such a chelator for the first time and show, by different physicochemical analysis, its tridentate nature and, importantly, its capacity to chelate iron with enough strength to inhibit both iron-dependent H(2)O(2) generation and lipid peroxidation in in vitro biological systems. 相似文献
109.
110.