全文获取类型
收费全文 | 12291篇 |
免费 | 845篇 |
国内免费 | 50篇 |
专业分类
耳鼻咽喉 | 196篇 |
儿科学 | 388篇 |
妇产科学 | 306篇 |
基础医学 | 1715篇 |
口腔科学 | 743篇 |
临床医学 | 1030篇 |
内科学 | 2584篇 |
皮肤病学 | 307篇 |
神经病学 | 1077篇 |
特种医学 | 225篇 |
外科学 | 1452篇 |
综合类 | 79篇 |
一般理论 | 3篇 |
预防医学 | 1226篇 |
眼科学 | 326篇 |
药学 | 841篇 |
中国医学 | 64篇 |
肿瘤学 | 624篇 |
出版年
2023年 | 121篇 |
2022年 | 120篇 |
2021年 | 524篇 |
2020年 | 318篇 |
2019年 | 414篇 |
2018年 | 474篇 |
2017年 | 338篇 |
2016年 | 345篇 |
2015年 | 371篇 |
2014年 | 483篇 |
2013年 | 616篇 |
2012年 | 946篇 |
2011年 | 968篇 |
2010年 | 559篇 |
2009年 | 424篇 |
2008年 | 723篇 |
2007年 | 687篇 |
2006年 | 629篇 |
2005年 | 596篇 |
2004年 | 467篇 |
2003年 | 419篇 |
2002年 | 360篇 |
2001年 | 244篇 |
2000年 | 273篇 |
1999年 | 228篇 |
1998年 | 82篇 |
1997年 | 57篇 |
1996年 | 32篇 |
1995年 | 31篇 |
1994年 | 46篇 |
1993年 | 35篇 |
1992年 | 146篇 |
1991年 | 126篇 |
1990年 | 119篇 |
1989年 | 99篇 |
1988年 | 87篇 |
1987年 | 56篇 |
1986年 | 74篇 |
1985年 | 67篇 |
1984年 | 46篇 |
1983年 | 38篇 |
1982年 | 26篇 |
1981年 | 21篇 |
1980年 | 20篇 |
1979年 | 36篇 |
1978年 | 38篇 |
1976年 | 23篇 |
1974年 | 25篇 |
1969年 | 19篇 |
1967年 | 23篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
1.
2.
3.
Emma J. Walker Noni E. MacDonald Nehal Islam Nicole Le Saux Karina A. Top Deshayne B. Fell 《Vaccine》2019,37(13):1725-1735
Objective
To systematically review literature on uptake and timeliness of diphtheria-tetanus-pertussis, measles-mumps-rubella, and/or polio-containing vaccines in infants who were born preterm, with a low birth weight, and/or with chronic health conditions that were diagnosed within the first 6?months of life.Methods
Using a standardized search strategy developed by a medical librarian, records were extracted from MEDLINE, Embase, Database of Abstracts of Reviews of Effects, and CINAHL up to May 8, 2018.Results
Out of the 1997 records that were screened, we identified 21 studies that met inclusion criteria. Eleven studies assessed vaccine coverage and/or timeliness in preterm infants, 6 in low birth weight infants, and 7 in children with chronic health conditions. Estimates of coverage in these populations were highly variable, ranging from 40% to 100% across the vaccines and population groups.Conclusions
There is a lack of studies reporting coverage and timeliness of routine immunizations in special populations of children.Policy implications
Our review suggests a need for improved surveillance of immunization status in special populations of infants, as well as a need for standardization of reporting practices. 相似文献4.
Del Lama Rafael Silva Candido Raquel Mariana Chiari-Correia Natália Santana Nogueira-Barbosa Marcello Henrique de Azevedo-Marques Paulo Mazzoncini Tinós Renato 《Journal of digital imaging》2022,35(3):446-458
Journal of Digital Imaging - Vertebral Compression Fracture (VCF) occurs when the vertebral body partially collapses under the action of compressive forces. Non-traumatic VCFs can be secondary to... 相似文献
5.
Maite Cruz Piqueras Ainhoa Rodríguez García de Cortazar Joaquín Hortal Carmona Javier Padilla Bernáldez 《Gaceta sanitaria / S.E.S.P.A.S》2019,33(1)
Objective
To analyse and understand vaccination hesitancy discourses, particularly those of people who have decided not to vaccinate their sons and daughters.Methods
Qualitative study of five individual interviews and two focus groups with people who chose not to vaccinate their children in the province of Granada (Spain).Results
Mothers and fathers manifest a system of health beliefs different to the biomedical paradigm. From an ethical point of view, they justify their position based on the right to autonomy and responsibility for their decisions. Alleged specific reasons: they doubt administration of several vaccines simultaneously at an early age in a systematic way and without individualising each case; they fear adverse effects and do not understand the variations of the vaccination schedule.Conclusions
These vaccination hesitancy discourses respond to the individual vs collective conflict; parents defend their right to bring up their children without any interference from the state and focus their responsibility on the individual welfare of their sons and daughters, regardless of the consequences that their actions might have on the collective. In their management of risks, they consider those derived from vaccination more relevant than the individual or collective consequences of not doing so. The vaccines generating most doubts are the more controversial ones within the scientific world. Transparency in communication of adverse effects; authorities respect for other health/disease concepts; banishment of the term “anti-vaccines” from the media and scientific vocabulary, and developing spaces for dialogue are bridges to be built. 相似文献6.
7.
Shelly A. Cruz Zhaohong Qin Konrad M. Ricke Alexandre F.R. Stewart Hsiao-Huei Chen 《中国神经再生研究》2021,16(1):129
Ischemic brain injury causes neuronal death and inflammation. Inflammation activates protein-tyrosine phosphatase 1B (PTP1B). Here, we tested the significance of PTP1B activation in glutamatergic projection neurons on functional recovery in two models of stroke: by photothrombosis, focal ischemic lesions were induced in the sensorimotor cortex (SM stroke) or in the peri-prefrontal cortex (peri-PFC stroke). Elevated PTP1B expression was detected at 4 days and up to 6 weeks after stroke. While ablation of PTP1B in neurons of neuronal knockout (NKO) mice had no effect on the volume or resorption of ischemic lesions, markedly different effects on functional recovery were observed. SM stroke caused severe sensory and motor deficits (adhesive removal test) in wild type and NKO mice at 4 days, but NKO mice showed drastically improved sensory and motor functional recovery at 8 days. In addition, peri-PFC stroke caused anxiety-like behaviors (elevated plus maze and open field tests), and depression-like behaviors (forced swimming and tail suspension tests) in wild type mice 9 and 28 days after stroke, respectively, with minimal effect on sensory and motor function. Peri-PFC stroke-induced affective disorders were associated with fewer active (FosB+) neurons in the PFC and nucleus accumbens but more FosB+ neurons in the basolateral amygdala, compared to sham-operated mice. In contrast, mice with neuronal ablation of PTP1B were protected from anxiety-like and depression-like behaviors and showed no change in FosB+ neurons after peri-PFC stroke. Taken together, our study identifies neuronal PTP1B as a key component that hinders sensory and motor functional recovery and also contributes to the development of anxiety-like and depression-like behaviors after stroke. Thus, PTP1B may represent a novel therapeutic target to improve stroke recovery. All procedures for animal use were approved by the Animal Care and Use Committee of the University of Ottawa Animal Care and Veterinary Service (protocol 1806) on July 27, 2018.Key Words: adhesive removal test, anxiety, depression, elevated plus maze, forced swimming test, Iba1, interleukin-1β, microglia, open field test, tail suspension test, tumor necrosis factor-αChinese Library Classification No. R453; R741; R364.5 相似文献
8.
9.
Gary E. Stapleton Benjamin W. Eidem Ricardo H. Pignatelli Karina M. Carlson Charles E. Mullins Ronald G. Grifka 《Congenital heart disease》2006,1(3):116-119
Background. A persistent patent ductus arteriosus (PDA) may delay closure of a coexisting atrial septal defect (ASD) due to volume loading and enlargement of the left atrium. The purpose of this study was to investigate the natural history of ASD size in patients with a PDA following transcatheter PDA occlusion. Methods. All patients with an ASD and a PDA who underwent transcatheter PDA occlusion at Texas Children’s Hospital were identified. Patients with ASD diameter <3 mm, or additional cardiac defects were excluded. Eight patients (7 females) with small‐ to moderate‐sized ASDs and a PDA were identified. Patient demographics, echocardiographic data, and cardiac catheterization data were recorded. Data were analyzed by 1‐tailed t‐test. Results. Following PDA occlusion, ASD diameter decreased in 6 of 8 patients by a mean of 3.8 mm (±2.3 mm), including 2 that closed. The median duration of follow‐up was 689 days. One ASD remained unchanged and 1 increased in size. The mean maximum ASD diameter decreased from 6.4 mm (±2.2 mm) to 3.9 mm (±3.4 mm) (P = .03). Two patients underwent subsequent transcatheter ASD occlusion. Conclusion. Following transcatheter PDA occlusion, small‐ to moderate‐sized ASDs have significant probability to decrease in size, and possibly close. In infants and children, we recommend transcatheter PDA occlusion, and serial follow‐up of the size of the ASD. This will allow many small‐ to moderate‐sized ASDs to either close, or become smaller, obviating the need for future intervention. 相似文献
10.