全文获取类型
收费全文 | 6530篇 |
免费 | 517篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 47篇 |
儿科学 | 255篇 |
妇产科学 | 188篇 |
基础医学 | 821篇 |
口腔科学 | 116篇 |
临床医学 | 617篇 |
内科学 | 1443篇 |
皮肤病学 | 80篇 |
神经病学 | 496篇 |
特种医学 | 257篇 |
外国民族医学 | 1篇 |
外科学 | 1002篇 |
综合类 | 349篇 |
一般理论 | 1篇 |
预防医学 | 470篇 |
眼科学 | 102篇 |
药学 | 307篇 |
1篇 | |
中国医学 | 7篇 |
肿瘤学 | 493篇 |
出版年
2021年 | 73篇 |
2020年 | 45篇 |
2019年 | 66篇 |
2018年 | 93篇 |
2017年 | 65篇 |
2016年 | 81篇 |
2015年 | 128篇 |
2014年 | 136篇 |
2013年 | 186篇 |
2012年 | 285篇 |
2011年 | 277篇 |
2010年 | 209篇 |
2009年 | 187篇 |
2008年 | 285篇 |
2007年 | 274篇 |
2006年 | 293篇 |
2005年 | 283篇 |
2004年 | 283篇 |
2003年 | 218篇 |
2002年 | 244篇 |
2001年 | 235篇 |
2000年 | 193篇 |
1999年 | 183篇 |
1998年 | 95篇 |
1997年 | 81篇 |
1996年 | 75篇 |
1995年 | 79篇 |
1994年 | 76篇 |
1993年 | 46篇 |
1992年 | 176篇 |
1991年 | 164篇 |
1990年 | 131篇 |
1989年 | 147篇 |
1988年 | 130篇 |
1987年 | 153篇 |
1986年 | 120篇 |
1985年 | 115篇 |
1984年 | 101篇 |
1983年 | 73篇 |
1982年 | 57篇 |
1981年 | 46篇 |
1980年 | 41篇 |
1979年 | 62篇 |
1978年 | 57篇 |
1977年 | 44篇 |
1976年 | 53篇 |
1975年 | 52篇 |
1974年 | 60篇 |
1973年 | 48篇 |
1972年 | 42篇 |
排序方式: 共有7053条查询结果,搜索用时 265 毫秒
1.
2.
3.
Fiene Marie Kuijper Uma V. Mahajan Seul Ku Daniel A.N. Barbosa Sheila M. Alessi Sherman C. Stein Kyle M. Kampman Brandon S. Bentzley Casey H. Halpern 《Neuromodulation》2022,25(2):253-262
ObjectivesCocaine is the second most frequently used illicit drug worldwide (after cannabis), and cocaine use disorder (CUD)-related deaths increased globally by 80% from 1990 to 2013. There is yet to be a regulatory-approved treatment. Emerging preclinical evidence indicates that deep brain stimulation (DBS) of the nucleus accumbens may be a therapeutic option. Prior to expanding the costly investigation of DBS for treatment of CUD, it is important to ensure societal cost-effectiveness.AimsWe conducted a threshold and cost-effectiveness analysis to determine the success rate at which DBS would be equivalent to contingency management (CM), recently identified as the most efficacious therapy for treatments of CUDs.Materials and MethodsQuality of life, efficacy, and safety parameters for CM were obtained from previous literature. Costs were calculated from a societal perspective. Our model predicted the utility benefit based on quality-adjusted life-years (QALYs) and incremental-cost-effectiveness ratio resulting from two treatments on a one-, two-, and five-year timeline.ResultsOn a one-year timeline, DBS would need to impart a success rate (ie, cocaine free) of 70% for it to yield the same utility benefit (0.492 QALYs per year) as CM. At no success rate would DBS be more cost-effective (incremental-cost-effectiveness ratio <$50,000) than CM during the first year. Nevertheless, as DBS costs are front loaded, DBS would need to achieve success rates of 74% and 51% for its cost-effectiveness to exceed that of CM over a two- and five-year period, respectively.ConclusionsWe find DBS would not be cost-effective in the short term (one year) but may be cost-effective in longer timelines. Since DBS holds promise to potentially be a cost-effective treatment for CUDs, future randomized controlled trials should be performed to assess its efficacy. 相似文献
4.
青年学者常常在完成资料收集和分析之后对获得的结果充满了激情。然而,在开始写作论文时,这种热情常常锐减。事实也如此,国家级学术会议的论文数远高于最终发表的医学文献数。优秀的研究成果不能发表的原因2大多在于写作新手在开始写作时对写作的认识混乱和畏缩。一般产生畏缩的原因有2个:要么是研究者不知从何着手,要么是不知如何组织文章结构。不过,大部分放射学论文的写作均有规律可寻,在很大程度上是程式化的。本文试图介绍一种可应用于典型放射学论文的逐段写作法。如果初学者能够完成按照本文教授的18段写作,其论文将具有合理的结构,… 相似文献
5.
MUAMMER SEYHAN BAAK KANDI COKUN HÜLYA SALAM HAMDI ÖZCAN YELDA KARINCAOLU 《Pediatrics international》2006,48(6):525-530
BACKGROUND: The present study was aimed to define the gender ratio, familial occurrence, age of onset, precipitating factors, clinical types, nail and joint involvement of psoriasis in childhood and adolescence in Turkey. METHODS: A total of 61 children with psoriasis under 18 years old were evaluated retrospectively, for age, gender, age of disease onset, family history, concomitant disease, the clinical type of psoriasis, clinical localization, nail and joint involvement and treatment modalities. RESULTS: Of the patients, 23 (37.70%) were boys and 38 (62.30%) were girls. Mean age was 9.28 +/- 4.02 years in girls and 11.18 +/- 3.85 years in boys (9.96 +/- 4.03 years in all children). Mean age at the onset of the disease was 6.81 +/- 4.11 years in girls and 7.03 +/- 4.28 years in boys (6.89 +/- 4.14 years in all patients). In 14 (23%) cases, a positive family history was detected. The most frequent probable triggering factors were upper respiratory tract infections (14.8%) and positive throat culture for A group ss-hemolytic streptococcus (21.3%). Frequency of emotional stress and psychiatric morbidity were 54% and 9.8%, respectively. The most frequent localizations at onset were trunk (44.3%), extremities (54.0%), and scalp (36.0%). Three children (4.9%) had a history of dissemination from psoriatic diaper rash. In total, 51 (83.6%) patients presented with psoriasis vulgaris, eight (13.1%) with generalized pustular psoriasis, and the remaining two (3.3%) with erythrodermic psoriasis. CONCLUSION: The incidence of psoriasis among dermatological patients in childhood and adolescence was 3.8%. The disease tends to appear earlier in girls than boys. The authors suggested that stress and upper respiratory infections are the most important triggering factors in childhood and adolescence psoriasis. 相似文献
6.
V Aerra M Kuduvalli AN Moloto AK Srinivasan AD Grayson BM Fabri AY Oo 《Journal of cardiothoracic surgery》2006,1(1):6-5
Background
Atrial fibrillation can occur in up to 40% of patients undergoing coronary surgery. 相似文献7.
8.
9.
Dependence of cardiac 11C-meta-hydroxyephedrine retention on norepinephrine transporter density. 总被引:1,自引:0,他引:1
David M Raffel Wei Chen Phillip S Sherman David L Gildersleeve Yong-Woon Jung 《Journal of nuclear medicine》2006,47(9):1490-1496
The norepinephrine analog (11)C-meta-hydroxyephedrine (HED) is used with PET to map the regional distribution of cardiac sympathetic neurons. HED is rapidly transported into sympathetic neurons by the norepinephrine transporter (NET) and stored in vesicles. Although much is known about the neuronal mechanisms of HED uptake and retention, there is little information about the functional relationship between HED retention and cardiac sympathetic nerve density. The goal of this study was to characterize the dependence of HED retention on nerve density in rats with graded levels of cardiac denervation induced chemically with the neurotoxin 6-hydroxydopamine (6-OHDA). METHODS: Thirty male Sprague-Dawley rats were divided into 6 groups, and each group was administered a different dose of 6-OHDA: 0 (controls), 7, 11, 15, 22, and 100 mg/kg intraperitoneally. One day after 6-OHDA injection, HED (3.7-8.3 MBq) was injected intravenously into each animal and HED concentrations in heart and blood at 30 min after injection were determined. Heart tissues were frozen and later processed by tissue homogenization and differential centrifugation into a membrane preparation for in vitro measurement of cardiac NET density. A saturation binding assay using (3)H-mazindol as the radioligand was used to measure NET density (maximum number of binding sites [B(max)], fmol/mg protein) for each heart. RESULTS: In control animals, NET B(max) was 388 +/- 23 fmol/mg protein and HED heart uptake (HU) at 30 min was 2.89% +/- 0.35 %ID/g (%ID/g is percentage injected dose per gram tissue). The highest 6-OHDA dose of 100 mg/kg caused severe cardiac denervation, decreasing both NET B(max) and HED HU to 8% of their control values. Comparing values for all doses of 6-OHDA, HED retention had a strong linear correlation with NET density: HU = 0.0077B(max) -0.028, r(2) = 0.95. CONCLUSION: HED retention is linearly dependent on NET density in rat hearts that have been chemically denervated with 6-OHDA, suggesting that HED retention is a good surrogate measure of NET density in the rat heart. This finding is discussed in relation to clinical observations of the dependence of HED retention on cardiac nerve density in human subjects using PET. 相似文献
10.