全文获取类型
收费全文 | 988篇 |
免费 | 77篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 57篇 |
妇产科学 | 8篇 |
基础医学 | 95篇 |
口腔科学 | 29篇 |
临床医学 | 169篇 |
内科学 | 212篇 |
皮肤病学 | 13篇 |
神经病学 | 42篇 |
特种医学 | 243篇 |
外科学 | 58篇 |
综合类 | 22篇 |
预防医学 | 34篇 |
眼科学 | 8篇 |
药学 | 42篇 |
中国医学 | 5篇 |
肿瘤学 | 33篇 |
出版年
2024年 | 3篇 |
2023年 | 8篇 |
2022年 | 2篇 |
2021年 | 11篇 |
2020年 | 7篇 |
2019年 | 6篇 |
2018年 | 23篇 |
2017年 | 12篇 |
2016年 | 19篇 |
2015年 | 22篇 |
2014年 | 28篇 |
2013年 | 28篇 |
2012年 | 25篇 |
2011年 | 25篇 |
2010年 | 40篇 |
2009年 | 60篇 |
2008年 | 31篇 |
2007年 | 11篇 |
2006年 | 17篇 |
2005年 | 5篇 |
2004年 | 9篇 |
2003年 | 16篇 |
2002年 | 11篇 |
2001年 | 16篇 |
2000年 | 11篇 |
1999年 | 13篇 |
1998年 | 49篇 |
1997年 | 53篇 |
1996年 | 65篇 |
1995年 | 49篇 |
1994年 | 43篇 |
1993年 | 47篇 |
1992年 | 14篇 |
1991年 | 7篇 |
1990年 | 15篇 |
1989年 | 36篇 |
1988年 | 30篇 |
1987年 | 33篇 |
1986年 | 35篇 |
1985年 | 23篇 |
1984年 | 16篇 |
1983年 | 9篇 |
1982年 | 22篇 |
1981年 | 15篇 |
1980年 | 8篇 |
1979年 | 2篇 |
1978年 | 5篇 |
1977年 | 12篇 |
1976年 | 11篇 |
1975年 | 14篇 |
排序方式: 共有1073条查询结果,搜索用时 15 毫秒
101.
Wiers RW Bartholow BD van den Wildenberg E Thush C Engels RC Sher KJ Grenard J Ames SL Stacy AW 《Pharmacology, biochemistry, and behavior》2007,86(2):263-283
This paper presents a review and a model of the development of addictive behaviors in (human) adolescents, with a focus on alcohol. The model proposes that addictive behaviors develop as the result of an imbalance between two systems: an appetitive, approach-oriented system that becomes sensitized with repeated alcohol use and a regulatory executive system that is not fully developed and that is compromised by exposure to alcohol. Self-regulation critically depends on two factors: ability and motivation to regulate the appetitive response tendency. The motivational aspect is often still weak in heavy drinking adolescents, who typically do not recognize their drinking as problematic. Motivation to regulate use often develops only years later, after the individual has encountered serious alcohol-related problems. Unfortunately, at that point behavioral change becomes harder due to several neurocognitive adaptations that result from heavy drinking. As we document, there is preliminary support for the central elements of the model (appetitive motivation vs. self-regulation), but there is a paucity of research directly addressing these mechanisms in human adolescents. Further, we emphasize that adolescent alcohol use primarily takes place in a social context, and that therefore studies should not solely focus on intra-individual factors predicting substance use and misuse but also on interpersonal social factors. Finally, we discuss implications of the model for interventions. 相似文献
102.
Kemler MA de Vet HC Barendse GA van den Wildenberg FA van Kleef M 《Journal of neurosurgery》2008,108(2):292-298
OBJECT: Chronic complex regional pain syndrome-Type I (CRPS-I) is a painful, disabling disorder for which no treatment with proven effect is available. In the present randomized controlled trial, the authors assessed the effectiveness of spinal cord stimulation (SCS) in reducing pain due to CRPS-I at the 5-year follow-up. METHODS: The authors performed a randomized trial in a 2:1 ratio in which 36 patients with CRPS-I were allocated to receive SCS and physical therapy (PT) and 18 patients to receive PT alone. Twenty-four patients who received SCS+PT also underwent placement of a permanent spinal cord stimulator after successful test stimulation; the remaining 12 patients did not receive a permanent stimulator. The authors assessed pain intensity, global perceived effect, treatment satisfaction, and health-related quality of life. Patients were examined before randomization, before implantation, and every year until 5 years thereafter. Ten patients were excluded from the final analysis. RESULTS: At 5 years posttreatment, SCS+PT produced results similar to those following PT for pain relief and all other measured variables. In a subgroup analysis, the results with regard to global perceived effect (p=0.02) and pain relief (p=0.06) in 20 patients with an implant exceeded those in 13 patients who received PT. CONCLUSIONS: Despite the diminishing effectiveness of SCS over time, 95% of patients with an implant would repeat the treatment for the same result. 相似文献
103.
Ayako Kokubo ME Mitsuo Kuwabara PhD Naoko Tomitani BSc Shingo Yamashita ME Toshikazu Shiga PhD Kazuomi Kario MD PhD 《Journal of clinical hypertension (Greenwich, Conn.)》2023,25(4):388-392
Nocturnal blood pressure (BP) surge in seconds (sec-surge), which is characterized as acute transient BP elevation over several tens of seconds is induced by obstructive sleep apnea (OSA) and OSA-related sympathetic hyperactivity. The authors assessed the relationship between sec-surge and arterial stiffness in 34 nocturnal hypertensive patients with suspected OSA (mean age 63.9 ± 12.6 years, 32.4% female). During the night, they had beat-by-beat (BbB) BP and cuff-oscillometric BP measurements, and brachial-ankle pulse wave velocity (baPWV) was assessed as an arterial stiffness index. Multiple linear regression analysis revealed that the upward duration (UD) of sec-surge was significantly associated with baPWV independently of nocturnal oscillometric systolic BP variability (β = .365, p = .046). This study suggests that the UD of sec-surge, which can only be measured using a BbB BP monitoring device, may be worth monitoring in addition to nocturnal BP level. 相似文献
104.
Rui Wang ME Shiyu Yan ME Xue Ma ME Jinfeng Zhao ME Yuqing Han ME Yao Pan PhD Hua Zhao PhD 《Journal of Cosmetic Dermatology》2023,22(12):3427-3435
Background
The semiactive or inactive probiotics or their extracts used in dermatology have interesting properties to ameliorate signs of irritated skin and enhance the skin barrier. Bifidobacterium, as the most common probiotics, which has been found to be effective in reducing acne and improving the skin barrier function of atopic dermatitis. Bifida Ferment Lysate (BFL) can be obtained from Bifidobacterium by fermentation and extraction.Purpose
In this study, we investigated the effect of a topically used BFL on the skin using in vitro evaluation methods.Results
The results showed that upregulation of skin physical barrier gene (FLG, LOR, IVL, TGM1, and AQP3) and antimicrobial peptide gene (CAMP and hBD-2) in HaCaT cells by BFL might be responsible for skin barrier resistance. In addition, BFL had strong antioxidant properties representing a dose-dependent increasing of the scavenging capacity of DPPH, ABTS, hydroxyl, and superoxide radicals. BFL treatment also fundamentally inhibited the intracellular ROS and MDA production and improved the activities of antioxidant enzymes (CAT and GSH-Px) in H2O2-stimulated HaCaT cells. As a good immunomodulatory factor, BFL efficiently decreased the secretion of IL-8 and TNF-α cytokines, and COX-2 mRNA expression in LPS-induced THP-1 macrophages.Conclusion
BFL can strengthen the skin barrier function and stimulate skin barrier resistance, to reinforce the skin against oxidative stress and inflammatory stimuli. 相似文献105.
Screening of candidate biomaterials for alveolar augmentation using a critical‐size rat calvaria defect model 下载免费PDF全文
106.
Suk Yun Kang MD PhD Toshiaki Wasaka PhD Ejaz A. Shamim MD Sungyoung Auh PhD Yoshino Ueki MD PhD Grisel J. Lopez MD Tetsuo Kida PhD Seung‐Hyun Jin PhD Nguyet Dang ME Mark Hallett MD 《Movement disorders》2010,25(13):2148-2155
The sequence effect (SE) in Parkinson's disease (PD) is progressive slowing of sequential movements. It is a feature of bradykinesia, but is separate from a general slowness without deterioration over time. It is commonly seen in PD, but its physiology is unclear. We measured general slowness and the SE separately with a computer‐based, modified Purdue pegboard in 11 patients with advanced PD. We conducted a placebo‐controlled, four‐way crossover study to learn whether levodopa and repetitive transcranial magnetic stimulation (rTMS) could improve general slowness or the SE. We also examined the correlation between the SE and clinical fatigue. Levodopa alone and rTMS alone improved general slowness, but rTMS showed no additive effect on levodopa. Levodopa alone, rTMS alone, and their combination did not alleviate the SE. There was no correlation between the SE and fatigue. This study suggests that dopaminergic dysfunction and abnormal motor cortex excitability are not the relevant mechanisms for the SE. Additionally, the SE is not a component of clinical fatigue. Further work is needed to establish the physiology and clinical relevance of the SE. © 2010 Movement Disorder Society. 相似文献
107.
108.
The right mid-lung window 总被引:1,自引:0,他引:1
Goodman LR; Golkow RS; Steiner RM; Teplick SK; Haskin ME; Himmelstein E; Teplick JG 《Radiology》1982,143(1):135
109.
Marleen Straat Marcella CA Müller Joost CM Meijers Mendi S Arbous Angelique ME Spoelstra - de Man Charlotte JP Beurskens Margreeth B Vroom Nicole P Juffermans 《Critical care (London, England)》2015,19(1)
IntroductionMuch controversy exists on the effect of a fresh frozen plasma (FFP) transfusion on systemic inflammation and endothelial damage. Adverse effects of FFP have been well described, including acute lung injury. However, it is also suggested that a higher amount of FFP decreases mortality in trauma patients requiring a massive transfusion. Furthermore, FFP has an endothelial stabilizing effect in experimental models. We investigated the effect of fresh frozen plasma transfusion on systemic inflammation and endothelial condition.MethodsA prospective predefined substudy of a randomized trial in coagulopathic non-bleeding critically ill patients receiving a prophylactic transfusion of FFP (12 ml/kg) prior to an invasive procedure. Levels of inflammatory cytokines and markers of endothelial condition were measured in paired samples of 33 patients before and after transfusion. The statistical tests used were paired t test or the Wilcoxon signed-rank test.ResultsAt baseline, systemic cytokine levels were mildly elevated in critically ill patients. FFP transfusion resulted in a decrease of levels of TNF-α (from 11.3 to 2.3 pg/ml, P = 0.01). Other cytokines were not affected. FFP also resulted in a decrease in systemic syndecan-1 levels (from 675 to 565 pg/ml, P = 0.01) and a decrease in factor VIII levels (from 246 to 246%, P <0.01), suggestive of an improved endothelial condition. This was associated with an increase in ADAMTS13 levels (from 24 to 32%, P <0.01) and a concomitant decrease in von Willebrand factor (vWF) levels (from 474 to 423%, P <0.01).ConclusionsA fixed dose of FFP transfusion in critically ill patients decreases syndecan-1 and factor VIII levels, suggesting a stabilized endothelial condition, possibly by increasing ADAMTS13, which is capable of cleaving vWF.
Trial registrations
Trialregister.nl NTR2262, registered 26 March 2010 and Clinicaltrials.gov , registered 14 June 2010. NCT01143909相似文献110.