收费全文 | 3916篇 |
免费 | 339篇 |
国内免费 | 64篇 |
耳鼻咽喉 | 13篇 |
儿科学 | 24篇 |
妇产科学 | 35篇 |
基础医学 | 257篇 |
口腔科学 | 20篇 |
临床医学 | 597篇 |
内科学 | 539篇 |
皮肤病学 | 14篇 |
神经病学 | 691篇 |
特种医学 | 21篇 |
外科学 | 559篇 |
综合类 | 127篇 |
一般理论 | 4篇 |
预防医学 | 119篇 |
眼科学 | 4篇 |
药学 | 1207篇 |
中国医学 | 34篇 |
肿瘤学 | 54篇 |
2024年 | 8篇 |
2023年 | 78篇 |
2022年 | 124篇 |
2021年 | 184篇 |
2020年 | 210篇 |
2019年 | 260篇 |
2018年 | 210篇 |
2017年 | 209篇 |
2016年 | 158篇 |
2015年 | 143篇 |
2014年 | 161篇 |
2013年 | 416篇 |
2012年 | 133篇 |
2011年 | 96篇 |
2010年 | 133篇 |
2009年 | 123篇 |
2008年 | 143篇 |
2007年 | 140篇 |
2006年 | 115篇 |
2005年 | 97篇 |
2004年 | 103篇 |
2003年 | 134篇 |
2002年 | 83篇 |
2001年 | 85篇 |
2000年 | 55篇 |
1999年 | 60篇 |
1998年 | 53篇 |
1997年 | 56篇 |
1996年 | 61篇 |
1995年 | 47篇 |
1994年 | 30篇 |
1993年 | 28篇 |
1992年 | 29篇 |
1991年 | 35篇 |
1990年 | 28篇 |
1989年 | 21篇 |
1988年 | 29篇 |
1987年 | 31篇 |
1986年 | 40篇 |
1985年 | 52篇 |
1984年 | 44篇 |
1983年 | 27篇 |
1982年 | 21篇 |
1981年 | 10篇 |
1980年 | 8篇 |
1979年 | 5篇 |
1978年 | 2篇 |
1977年 | 1篇 |
Background:
Low-dose dextromethorphan (DM) might have anti-inflammatory and neurotrophic effects mechanistically remote from an NMDA receptor. In a randomized, double-blind, controlled 12 week study, we investigated whether add-on dextromethorphan reduced cytokine levels and benefitted opioid-dependent patients undergoing methadone maintenance therapy (MMT).Methods:
Patients were randomly assigned to a group: DM60 (60mg/day dextromethorphan; n = 65), DM120 (120mg/day dextromethorphan; n = 65), or placebo (n = 66). Primary outcomes were the methadone dose required, plasma morphine level, and retention in treatment. Plasma tumor necrosis factor (TNF)-α, C-reactive protein, interleukin (IL)-6, IL-8, transforming growth factor–β1, and brain-derived neurotrophic factor (BDNF) levels were examined during weeks 0, 1, 4, 8, and 12. Multiple linear regressions with generalized estimating equation methods were used to examine the therapeutic effect.Results:
After 12 weeks, the DM60 group had significantly longer treatment retention and lower plasma morphine levels than did the placebo group. Plasma TNF-α was significantly decreased in the DM60 group compared to the placebo group. However, changes in plasma cytokine levels, BDNF levels, and the methadone dose required in the three groups were not significantly different.Conclusions:
We provide evidence—decreased concomitant heroin use—of low-dose add-on DM’s efficacy for treating opioid-dependent patients undergoing MMT. 相似文献Areas covered: Pharmacology, characteristics, and use of opioids in clinical practice are presented.
Expert opinion: Although the use of opioids is largely accepted as a fundamental step for controlling cancer pain, existing data supporting this statement are poor. All opioids provide analgesia and are effective in controlling cancer pain. New drugs have been developed and experience is accumulating among clinicians. Despite these drugs having different pharmacokinetic and chemical properties, there is no proof that one opioid is better than another one. Thus, the optimum benefit depends on the experience of the users. Clinicians should weight evidence, clinical experience, patient preferences, and treatment costs when choosing the optimal treatment for an individual patient with cancer pain. New opioids with specific receptor activities are under investigation. 相似文献
Methods: This is a subgroup analysis of a 4- to 6-week multicenter, observational study. A total of 162 opioid-naïve patients with moderate-to-severe pain of varying etiologies received either OXN PR or other strong opioids (control group). Documented parameters include pain relief (numeric rating scale), bowel function (Bowel Function Index [BFI]), pain-related functional impairment (Brief Pain Inventory Short Form), quality of life (QoL; EuroQol EQ-5D-3L) and a global therapy assessment.
Results: OXN group patients experienced a substantial clinically important reduction in mean pain intensity of 51.4%, compared to a 28.6% reduction in control patients. Although the BFI remained in the reference range in both groups, there was a difference between BFI changes during treatment in favor of OXN PR. The superior effectiveness of OXN PR was paralleled by greater improvements of pain interference and QoL and fewer adverse drug reactions compared to other strong opioids.
Conclusion: The favorable outcomes under real-life conditions suggest that OXN PR provides a valuable option for treatment of moderate-to-severe pain without using weak opioids first. 相似文献
Methods: Pooled data from three randomized, placebo-controlled studies (two 6-month; one 12-month) of 18 mg nalmefene (as-needed use) in alcohol-dependent patients looking at the total population (placebo n = 824, nalmefene n = 1123) and patients with high/very high drinking risk levels at screening and randomization (target population: placebo n = 374, nalmefene n = 450).
Results: In the study, 62.7% of patients on placebo and 74.7% on nalmefene in the total population had treatment-emergent adverse events (TEAEs). Fourty-seven (5.9%) on placebo and 149 (13.0%) on nalmefene dropped out due to TEAEs. Thirty-five (4.4%) on placebo and 57 (5.0%) on nalmefene had serious adverse events. Tolerability and safety were similar in the target population and total population. Most frequent TEAEs were transient, mainly occurring at treatment initiation. There was no difference in tolerability and safety if nalmefene was taken daily or intermittently; no signal of increased risk of suicide-related behavior with nalmefene. The higher incidence of psychiatric events in the nalmefene group was mainly due to the TEAE of confusional state.
Conclusions: Although there was a higher incidence of TEAEs and TEAEs leading to dropout, nalmefene was well-tolerated and no major safety issues were identified. 相似文献