全文获取类型
收费全文 | 68874篇 |
免费 | 5535篇 |
国内免费 | 2172篇 |
专业分类
耳鼻咽喉 | 472篇 |
儿科学 | 3074篇 |
妇产科学 | 875篇 |
基础医学 | 9257篇 |
口腔科学 | 810篇 |
临床医学 | 6718篇 |
内科学 | 4679篇 |
皮肤病学 | 132篇 |
神经病学 | 18353篇 |
特种医学 | 3179篇 |
外国民族医学 | 5篇 |
外科学 | 3280篇 |
综合类 | 8058篇 |
现状与发展 | 6篇 |
一般理论 | 5篇 |
预防医学 | 6302篇 |
眼科学 | 544篇 |
药学 | 5904篇 |
31篇 | |
中国医学 | 2043篇 |
肿瘤学 | 2854篇 |
出版年
2024年 | 164篇 |
2023年 | 973篇 |
2022年 | 1596篇 |
2021年 | 2543篇 |
2020年 | 2467篇 |
2019年 | 2236篇 |
2018年 | 2051篇 |
2017年 | 2293篇 |
2016年 | 2398篇 |
2015年 | 2380篇 |
2014年 | 3762篇 |
2013年 | 5170篇 |
2012年 | 3624篇 |
2011年 | 3787篇 |
2010年 | 3390篇 |
2009年 | 3171篇 |
2008年 | 3349篇 |
2007年 | 3394篇 |
2006年 | 3124篇 |
2005年 | 2765篇 |
2004年 | 2267篇 |
2003年 | 2080篇 |
2002年 | 1721篇 |
2001年 | 1533篇 |
2000年 | 1250篇 |
1999年 | 1154篇 |
1998年 | 1093篇 |
1997年 | 1103篇 |
1996年 | 930篇 |
1995年 | 823篇 |
1994年 | 788篇 |
1993年 | 610篇 |
1992年 | 618篇 |
1991年 | 509篇 |
1990年 | 497篇 |
1989年 | 425篇 |
1988年 | 423篇 |
1987年 | 361篇 |
1986年 | 453篇 |
1985年 | 540篇 |
1984年 | 538篇 |
1983年 | 345篇 |
1982年 | 388篇 |
1981年 | 378篇 |
1980年 | 331篇 |
1979年 | 191篇 |
1978年 | 147篇 |
1977年 | 108篇 |
1976年 | 104篇 |
1975年 | 54篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
《Surgery (Oxford)》2022,40(11):731-737
Disorders of sex development (DSD) occur in 1–2/10,000 live births, with a specific molecular diagnosis only possible in 20% of cases. Presentation is usually at birth, and gender assignment must be avoided before review by an expert multidisciplinary team. Initial investigations allow a working diagnosis to be made within 48 hr. In 46,XY DSD, surgery may be necessary to correct hypospadias, reposition or remove undescended testes, and remove symptomatic Müllerian remnants. In 46,XX DSD, feminizing surgery is performed less frequently than in the past, but genitoplasty may still be indicated. Psychosocial support is required to promote positive adaptation as gender dissatisfaction can occur in certain conditions. Long-term outcome data are sparse. 相似文献
52.
53.
Antonio Sierra-Cedillo Miriam Figueroa-Olea Silvia Izazola-Ezquerro Rolando Rivera-González 《Early child development and care》2019,189(6):883-895
The concept of participation was reviewed as a component of children's citizenship in order to promote a programme for Integral Development. A narrative revision of the literature was carried out as well as a group discussion was organized along with the staff of an Integral Care Programme, in order to identify notions of democracy and child citizenship related to care and rearing. Some elements that favoured the child participation and some parenting skills were identified. Among the elements that must be encouraged in children are: the development of emotional, cognitive and communicative skills and promotion of decision-making; among the parent skills development included are: sensitivity and responsivity; establishing routines and participation experiences. It is important to stand out that the identified elements to promote child participation and parental competences should be adapted to every specific cultural context. 相似文献
54.
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
55.
Justin E. Karr Holly K. Rau Jane B. Shofer Rebecca C. Hendrickson Elaine R. Peskind Kathleen F. Pagulayan 《Journal of clinical and experimental neuropsychology》2019,41(7):680-693
Introduction: This study investigated variables associated with subjective decline in executive function among Veterans of Operations Enduring Freedom, Iraqi Freedom, and New Dawn (OEF/OIF/OND) following a history of blast-related mild traumatic brain injury (mTBI).Method: Fifty-six male U.S. Veterans (MAge = 35.3 ± 8.8 years) with a history of blast-related mTBI (6.6 ± 3.2 years post injury) completed a battery of self-report questionnaires and neuropsychological measures. Participants rated current and retrospectively estimated pre-mTBI executive function difficulties on the Frontal Systems Behavior Scale (FrSBe). A difference score (post- minus pre-mTBI ratings) was the dependent variable (?FrSBe). Linear regression models examined variables predicting ?FrSBe, including: pre-injury characteristics (education, premorbid intelligence), injury-related characteristics (number of blast exposures, losses of consciousness), post-injury clinical symptoms (PTSD Checklist–Military version; Pittsburgh Sleep Quality Index), and post-injury neuropsychological performances on executive function measures (Trail Making Test Part B; Controlled Oral Word Association Test; Auditory Consonant Trigrams; Wisconsin Card Sorting Test).Results: While 11% of participants had a clinically elevated pre-injury FrSBe total score, 82% had a clinically elevated post-injury FrSBe total score. Only self-reported PTSD symptom severity independently predicted perceived change in executive function.Conclusions: Many OEF/OIF/OND Veterans with a history of blast-related mTBI experience subjective decline in executive function following injury. Perceived executive function decline was associated with higher PTSD symptom severity, aligning with previous research associating PTSD with cognitive complaints. Results did not support a correspondence between perceived cognitive change and neuropsychological performances. 相似文献
56.
王昌燕 《中国儿童保健杂志》2019,27(4):421-424
目的 比较枸橼酸咖啡因和氨茶碱对早产儿神经行为发育的影响,为早产儿早期合理干预提供临床依据。方法 选择2014年6月-2018年6月在中国西电集团医院新生儿科住院接受枸橼酸咖啡因治疗的原发性呼吸暂停(AOP)早产儿62例作为研究组;2011 年 12 月-2014年5月同在中国西电集团医院新生儿科住院采用氨茶碱治疗的AOP患儿69例作为对照组。出生3~8 d及矫正胎龄40周时分别行头颅MRI检查,评估脑白质损伤(WMD)并进行两组比较;6个月及12个月时应用Gesell婴幼儿发育量表测试比较两组神经行为发育水平。结果 两组患儿在性别、出生胎龄及体重、产前孕母糖皮质激素应用及分娩方式、5 min Apgar评分、辅助通气和表面活性物质的应用等方面差异均无统计学意义(P>0.05)。首次头颅MRI显示两组患儿WMD差异无统计学意义(P>0.05)。矫正胎龄40周时头颅MRI显示,咖啡因组WMD较氨茶碱组明显改善,差异有统计学意义(P<0.05);且6个月及12个月时Gessell婴幼儿发育量表测试,随访至校正6月龄时,咖啡因组患儿的大运动、精细运动及个人-社交评分均高于氨茶碱组(P<0.05);随访至校正12月龄时,咖啡因组患儿的大运动、精细运动、语言、适应性评分均高于氨茶碱组(P<0.05)。结论 枸橼酸咖啡可明显改善AOP患儿6个月及12个月时的神经行为发育。 相似文献
57.
58.
59.
Imaging the infant brain with MRI has improved our understanding of early neurodevelopment. However, head motion during MRI acquisition is detrimental to both functional and structural MRI scan quality. Though infants are typically scanned while asleep, they commonly exhibit motion during scanning causing data loss. Our group has shown that providing MRI technicians with real-time motion estimates via Framewise Integrated Real-Time MRI Monitoring (FIRMM) software helps obtain high-quality, low motion fMRI data. By estimating head motion in real time and displaying motion metrics to the MR technician during an fMRI scan, FIRMM can improve scanning efficiency. Here, we compared average framewise displacement (FD), a proxy for head motion, and the amount of usable fMRI data (FD ≤ 0.2 mm) in infants scanned with (n = 407) and without FIRMM (n = 295). Using a mixed-effects model, we found that the addition of FIRMM to current state-of-the-art infant scanning protocols significantly increased the amount of usable fMRI data acquired per infant, demonstrating its value for research and clinical infant neuroimaging. 相似文献
60.
《Brain stimulation》2020,13(6):1668-1677
BackgroundEndovascular delivery of current using ‘stentrodes’ – electrode bearing stents – constitutes a potential alternative to conventional deep brain stimulation (DBS). The precise neuroanatomical relationships between DBS targets and the vascular system, however, are poorly characterized to date.ObjectiveTo establish the relationships between cerebrovascular system and DBS targets and investigate the feasibility of endovascular stimulation as an alternative to DBS.MethodsNeuroanatomical targets as employed during deep brain stimulation (anterior limb of the internal capsule, dentatorubrothalamic tract, fornix, globus pallidus pars interna, medial forebrain bundle, nucleus accumbens, pedunculopontine nucleus, subcallosal cingulate cortex, subthalamic nucleus, and ventral intermediate nucleus) were superimposed onto probabilistic vascular atlases obtained from 42 healthy individuals. Euclidian distances between targets and associated vessels were measured. To determine the electrical currents necessary to encapsulate the predefined neurosurgical targets and identify potentially side-effect inducing substrates, a preliminary volume of tissue activated (VTA) analysis was performed.ResultsSix out of ten DBS targets were deemed suitable for endovascular stimulation: medial forebrain bundle (vascular site: P1 segment of posterior cerebral artery), nucleus accumbens (vascular site: A1 segment of anterior cerebral artery), dentatorubrothalamic tract (vascular site: s2 segment of superior cerebellar artery), fornix (vascular site: internal cerebral vein), pedunculopontine nucleus (vascular site: lateral mesencephalic vein), and subcallosal cingulate cortex (vascular site: A2 segment of anterior cerebral artery). While VTAs effectively encapsulated mfb and NA at current thresholds of 3.5 V and 4.5 V respectively, incremental amplitude increases were required to effectively cover fornix, PPN and SCC target (mean voltage: 8.2 ± 4.8 V, range: 3.0–17.0 V). The side-effect profile associated with endovascular stimulation seems to be comparable to conventional lead implantation. Tailoring of targets towards vascular sites, however, may allow to reduce adverse effects, while maintaining the efficacy of neural entrainment within the target tissue.ConclusionsWhile several challenges remain at present, endovascular stimulation of select DBS targets seems feasible offering novel and exciting opportunities in the neuromodulation armamentarium. 相似文献