全文获取类型
收费全文 | 17905篇 |
免费 | 1556篇 |
国内免费 | 28篇 |
专业分类
耳鼻咽喉 | 234篇 |
儿科学 | 669篇 |
妇产科学 | 431篇 |
基础医学 | 2299篇 |
口腔科学 | 359篇 |
临床医学 | 2193篇 |
内科学 | 3111篇 |
皮肤病学 | 380篇 |
神经病学 | 1545篇 |
特种医学 | 554篇 |
外科学 | 2047篇 |
综合类 | 406篇 |
一般理论 | 10篇 |
预防医学 | 2288篇 |
眼科学 | 364篇 |
药学 | 1350篇 |
中国医学 | 36篇 |
肿瘤学 | 1213篇 |
出版年
2023年 | 121篇 |
2022年 | 193篇 |
2021年 | 399篇 |
2020年 | 260篇 |
2019年 | 368篇 |
2018年 | 444篇 |
2017年 | 346篇 |
2016年 | 374篇 |
2015年 | 394篇 |
2014年 | 551篇 |
2013年 | 811篇 |
2012年 | 1072篇 |
2011年 | 1197篇 |
2010年 | 640篇 |
2009年 | 581篇 |
2008年 | 914篇 |
2007年 | 938篇 |
2006年 | 870篇 |
2005年 | 932篇 |
2004年 | 844篇 |
2003年 | 765篇 |
2002年 | 689篇 |
2001年 | 407篇 |
2000年 | 387篇 |
1999年 | 342篇 |
1998年 | 149篇 |
1997年 | 124篇 |
1996年 | 128篇 |
1995年 | 118篇 |
1994年 | 107篇 |
1993年 | 95篇 |
1992年 | 236篇 |
1991年 | 257篇 |
1990年 | 225篇 |
1989年 | 232篇 |
1988年 | 228篇 |
1987年 | 221篇 |
1986年 | 246篇 |
1985年 | 221篇 |
1984年 | 175篇 |
1983年 | 165篇 |
1982年 | 109篇 |
1981年 | 76篇 |
1979年 | 134篇 |
1978年 | 102篇 |
1976年 | 76篇 |
1974年 | 100篇 |
1973年 | 110篇 |
1972年 | 107篇 |
1971年 | 79篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Hommes Franziska Mohsenpour Amir Kropff Dana Pilgram Lisa Matusall Svenja von Philipsborn Peter Sell Kerstin 《Bundesgesundheitsblatt, Gesundheitsforschung, Gesundheitsschutz》2022,65(1):96-106
Bundesgesundheitsblatt - Gesundheitsforschung - Gesundheitsschutz - Akteure der öffentlichen Gesundheit (Public Health) tragen wesentlich zu Gesundheitsschutz, -förderung und... 相似文献
2.
Carlo De-Carolis Geraldine-A. Boyd Luca Mancinelli Stefano Pagano Stefano Eramo 《Medicina oral, patología oral y cirugía bucal》2015,20(2):e205-e210
With easy chemical synthesis from its precursor, methamphetamine (MA) is now widespread in many countries. The abuse of methamphetamine is associated with several negative effects on health, because MA is a neurotoxin and a dangerous central nervous system stimulant. It changes levels of neurotransmitters in the brain, releasing dopamine and inhibiting nor epinephrine uptake which increases sympathetic nervous system activity and can lead to cardiac arrhythmia, hypertension and tachypnea. The consequences of MA abuse are clearly manifested in oral diseases (like “meth mouth”) which is characterised by extensive caries, teeth grinding with ensuing dental wear and trismus. The present review was designed to fill the gap in knowledge about methamphetamine abuse in the European Union (EU) and to illustrate the main clinical effects of prolonged use. After describing the pharmacology and systemic effects of methamphetamine and concentrating on its effects on the mouth, the present review compares the epidemiology and incidence of abuse in the world, particularly the USA and the EU.
Key words:Methamphetamine, “Meth mouth”, drug abuse, oral health. 相似文献
3.
Danielle E Whittier Elizabeth J Samelson Marian T Hannan Lauren A Burt David A Hanley Emmanuel Biver Pawel Szulc Elisabeth Sornay-Rendu Blandine Merle Roland Chapurlat Eric Lespessailles Andy Kin On Wong David Goltzman Sundeep Khosla Serge Ferrari Mary L Bouxsein Douglas P Kiel Steven K Boyd 《Journal of bone and mineral research》2022,37(3):428-439
Prevalence of osteoporosis is more than 50% in older adults, yet current clinical methods for diagnosis that rely on areal bone mineral density (aBMD) fail to detect most individuals who have a fragility fracture. Bone fragility can manifest in different forms, and a “one-size-fits-all” approach to diagnosis and management of osteoporosis may not be suitable. High-resolution peripheral quantitative computed tomography (HR-pQCT) provides additive information by capturing information about volumetric density and microarchitecture, but interpretation is challenging because of the complex interactions between the numerous properties measured. In this study, we propose that there are common combinations of bone properties, referred to as phenotypes, that are predisposed to different levels of fracture risk. Using HR-pQCT data from a multinational cohort (n = 5873, 71% female) between 40 and 96 years of age, we employed fuzzy c-means clustering, an unsupervised machine-learning method, to identify phenotypes of bone microarchitecture. Three clusters were identified, and using partial correlation analysis of HR-pQCT parameters, we characterized the clusters as low density, low volume, and healthy bone phenotypes. Most males were associated with the healthy bone phenotype, whereas females were more often associated with the low volume or low density bone phenotypes. Each phenotype had a significantly different cumulative hazard of major osteoporotic fracture (MOF) and of any incident osteoporotic fracture (p < 0.05). After adjustment for covariates (cohort, sex, and age), the low density followed by the low volume phenotype had the highest association with MOF (hazard ratio = 2.96 and 2.35, respectively), and significant associations were maintained when additionally adjusted for femoral neck aBMD (hazard ratio = 1.69 and 1.90, respectively). Further, within each phenotype, different imaging biomarkers of fracture were identified. These findings suggest that osteoporotic fracture risk is associated with bone phenotypes that capture key features of bone deterioration that are not distinguishable by aBMD. © 2021 American Society for Bone and Mineral Research (ASBMR). 相似文献
4.
5.
Dana Franzen-Klein Mark Jankowski Charlotte L. Roy Hoa Nguyen-Phuc Da Chen Lorin Neuman-Lee 《Journal of toxicology and environmental health. Part A》2020,83(2):45-65
ABSTRACTDomestic chickens (Gallus gallus domesticus) were exposed to imidacloprid by gavage once daily for 7 consecutive days at 0, 0.03, 0.34, 3.42, 10.25, and 15.5 mg/kg/day (n = 20 per group; 5 6-week-old males, 5 6-week-old females, 5 9-week-old males, and 5 9-week-old females). The severity and duration of neurobehavioral abnormalities were recorded. Components of the innate and adaptive immune system were assessed with 7 standard functional assays. Temporary neurobehavioral abnormalities were observed in a dose-dependent manner, including muscle tremors, ataxia, and depressed mentation. Based upon mean clinical severity scores, the no observed adverse effect level (NOAEL) was 3.42 mg/kg/day, and the lowest observed adverse effect level (LOAEL) was 10.25 mg/kg/day. The effective dose value for the presence of any neurobehavioral abnormalities in 50% of the test group (ED50) was 4.62 ± 0.98 mg/kg/day. The ED50 for an adjusted score that included both severity and duration of neurobehavioral abnormalities was 11.24 ± 9.33 mg/kg/day. These ED50 values are equivalent to a 1 kg bird ingesting 29 or 70 imidacloprid treated soybean seeds respectively. Immunotoxicity was not documented, possible causes include the assays were insensitive, relevant immune functions were not examined, or imidacloprid is not immunotoxic at this dosing schedule in this species. Neurobehavioral abnormalities were a more sensitive indicator of the sublethal effects of imidacloprid than immunotoxicity. 相似文献
6.
Breast Elastography: How to Perform and Integrate Into a “Best-Practice” Patient Treatment Algorithm
Breast elastography has been available for more than 15 years but is not widely incorporated into clinical practice. Many publications report extremely high accuracy for various breast elastographic techniques. However, results in the literature are extremely variable. This variability is most likely due to variations in technique, a relatively steep learning curve, and variability in methods between vendors. This article describes our protocol for performing breast elastography using both strain elastography and shear wave elastography, which produces high sensitivity and specificity. Additionally, we will describe the most commonly known false-positive and false-negative lesions as well as how to detect them. 相似文献
7.
8.
9.
Mhd Wasem Alsabbagh Dana Church Lisa Wenger John Papastergiou Lalitha Raman-Wilms Eric Schneider Nancy Waite 《Research in social & administrative pharmacy》2019,15(2):202-206