全文获取类型
收费全文 | 2689401篇 |
免费 | 185686篇 |
国内免费 | 8330篇 |
专业分类
耳鼻咽喉 | 36327篇 |
儿科学 | 87198篇 |
妇产科学 | 73476篇 |
基础医学 | 365416篇 |
口腔科学 | 74047篇 |
临床医学 | 256460篇 |
内科学 | 534977篇 |
皮肤病学 | 65266篇 |
神经病学 | 223460篇 |
特种医学 | 102770篇 |
外国民族医学 | 736篇 |
外科学 | 400464篇 |
综合类 | 50489篇 |
现状与发展 | 44篇 |
一般理论 | 968篇 |
预防医学 | 206852篇 |
眼科学 | 58577篇 |
药学 | 189033篇 |
65篇 | |
中国医学 | 5340篇 |
肿瘤学 | 151452篇 |
出版年
2021年 | 22361篇 |
2019年 | 22723篇 |
2018年 | 34716篇 |
2017年 | 28455篇 |
2016年 | 32424篇 |
2015年 | 35701篇 |
2014年 | 48659篇 |
2013年 | 70060篇 |
2012年 | 82924篇 |
2011年 | 87022篇 |
2010年 | 56328篇 |
2009年 | 56339篇 |
2008年 | 81547篇 |
2007年 | 85536篇 |
2006年 | 88244篇 |
2005年 | 83222篇 |
2004年 | 79776篇 |
2003年 | 76834篇 |
2002年 | 74065篇 |
2001年 | 129892篇 |
2000年 | 132251篇 |
1999年 | 111879篇 |
1998年 | 32916篇 |
1997年 | 29430篇 |
1996年 | 29770篇 |
1995年 | 28710篇 |
1994年 | 25915篇 |
1993年 | 24141篇 |
1992年 | 85751篇 |
1991年 | 82066篇 |
1990年 | 79190篇 |
1989年 | 76460篇 |
1988年 | 69871篇 |
1987年 | 68288篇 |
1986年 | 63816篇 |
1985年 | 60724篇 |
1984年 | 45139篇 |
1983年 | 38176篇 |
1982年 | 22631篇 |
1981年 | 20130篇 |
1979年 | 39007篇 |
1978年 | 27542篇 |
1977年 | 23342篇 |
1976年 | 21568篇 |
1975年 | 22864篇 |
1974年 | 26848篇 |
1973年 | 25418篇 |
1972年 | 23806篇 |
1971年 | 21995篇 |
1970年 | 20244篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
121.
122.
123.
124.
Anne Beck Patricia Pelz Robert C. Lorenz Katrin Charlet Olga Geisel Andreas Heinz Torsten Wüstenberg Christian A. Müller 《European neuropsychopharmacology》2018,28(11):1206-1216
Increased functional brain response towards alcohol-associated stimuli is a neural hallmark of alcohol dependence and a promising target for pharmacotherapy. For the first time, we assessed the effects of individually titrated high-dose baclofen on cue reactivity and functional connectivity in alcohol-dependent (AD) patients in a randomized controlled trial (RCT).We investigated 23 recently detoxified AD patients and 23 matched healthy controls (HC) with a cue reactivity functional magnetic resonance imaging task. Patients were further scanned at baseline without medication and during treatment with high-dose baclofen/placebo (30–270 mg/d). Analyses were conducted for alcohol cue-elicited brain response, alcohol cue-modulated and stimulus-independent functional connectivity with left ventral tegmental area (VTA) as seed region.At baseline, AD patients (N?=?23) showed increased cue-elicited brain activation in the ventral striatum (VS) compared to HC (N?=?23), which was decreased at the second scanning session compared to baseline. Patients receiving baclofen (N?=?10) showed a significant stronger decrease in cue-elicited brain activation in left orbitofrontal cortex (OFC), bilateral amygdala and left VTA than patients receiving placebo (N?=?13). Treatment with baclofen further led to a decrease in alcohol cue-modulated functional connectivity between left VTA and left anterior cingulate cortex (ACC) as well as left medial prefrontal cortex (MPFC). Regarding clinical outcome, significantly more patients of the baclofen group remained abstinent during the high-dose period.Baclofen specifically decreased cue-elicited brain responses in areas known to be involved in the processing of salient (appetitive and aversive) stimuli. Treatment with high-dose baclofen seems to provide a pharmacological relief of this neural “warning signal” evoked by alcohol-related cues, thereby possibly supporting patients in remaining abstinent.Trial Registration Identifier of the main trial [BACLAD study] at clinicaltrials.gov: NCT01266655. 相似文献
125.
Ecotoxicology - Bracon hebetor Say (Hymenoptera: Braconidae) is an important biological control agent of various species of order Lepidoptera and extensively used in biological control program... 相似文献
126.
Birke J. Benedikter Emiel F. M. Wouters Paul H. M. Savelkoul Gernot G. U. Rohde 《Journal of toxicology and environmental health. Part B, Critical reviews》2018,21(3):142-160
Extracellular vesicles (EV) are secreted signaling entities that enhance various pathological processes when released in response to cellular stresses. Respiratory exposures such as cigarette smoke and air pollution exert cellular stresses and are associated with an increased risk of several chronic diseases. The aim of this review was to examine the evidence that modifications in EV contribute to respiratory exposure-associated diseases. Publications were searched using PubMed and Google Scholar with the search terms (cigarette smoke OR tobacco smoke OR air pollution OR particulate matter) AND (extracellular vesicles OR exosomes OR microvesicles OR microparticles OR ectosomes). All original research articles were included and reviewed. Fifty articles were identified, most of which investigated the effect of respiratory exposures on EV release in vitro (25) and/or on circulating EV in human plasma (24). The majority of studies based their main observations on the relatively insensitive scatter-based flow cytometry of EV (29). EV induced by respiratory exposures were found to modulate inflammation (19), thrombosis (13), endothelial dysfunction (11), tissue remodeling (6), and angiogenesis (3). By influencing these processes, EV may play a key role in the development of cardiovascular diseases and chronic obstructive pulmonary disease and possibly lung cancer and allergic asthma. The current findings warrant additional research with improved methodologies to evaluate the contribution of respiratory exposure-induced EV to disease etiology, as well as their potential as biomarkers of exposure or risk and as novel targets for preventive or therapeutic strategies. 相似文献
127.
Anmar M. Nassir Naiyer Shahzad Ibrahim A.A. Ibrahim Iqbal Ahmad Shadab Md Mohammad R. Ain 《Saudi Pharmaceutical Journal》2018,26(6):876-885
Resveratrol (RL), a natural polyphenol, is known for its diverse biological effects against various human cancer cell lines. But low aqueous solubility, poor bioavailability, and stability limit its efficacy against prostate cancer. In this study polymeric nanoparticles encapsulating resveratrol (RLPLGA) were designed and their cytotoxic and mode of apoptotic cells death against prostate cancer cell line (LNCaP) was determined. Nanoparticles were prepared by solvent displacement method and characterized for particle size, TEM, entrapment efficiency, DSC and drug release study. RLPLGA exhibited a significant decrease in cell viability with 50% and 90% inhibitory concentration (IC50 and IC90) of 15.6?±?1.49 and 41.1?±?2.19?μM respectively against the LNCaP cells. This effect was mediated by apoptosis as confirmed by cell cycle arrest at G1-S transition phase, externalization of phosphatidylserine, DNA nicking, loss of mitochondrial membrane potential and reactive oxygen species generation in LNCaP cells. Furthermore, significantly greater cytotoxicity to LNCaP cells was observed with nanoparticles as compared to that of free RL at all tested concentrations. RLPLGA nanoparticles presented no adverse cytotoxic effects on murine macrophages even at 200?μM. Our findings support the potential use of developed resveratrol loaded nanoparticle for the prostate cancer chemoprevention/ chemotherapy with no adverse effect on normal cells. 相似文献
128.
Maciej Masłyk Monika Janeczko Oleg M. Demchuk Anna Boguszewska-Czubara Hieronim Golczyk Anna Sierosławska Anna Rymuszka Aleksandra Martyna Konrad Kubiński 《Saudi Pharmaceutical Journal》2018,26(2):244-252
In this study, we applied various assays to reveal new activities of phenylcyanomethylenequinone oxime-4-(hydroxyimino) cyclohexa-2,5-dien-1-ylidene](phenyl)ethanenitrile (4-AN) for potential anti-microbial applications. These assays demonstrated (a) the antimicrobial effect on bacterial and fungal cultures, (b) the effect on the in vitro activity of the kinase CK2, (c) toxicity towards human erythrocytes, the Caco-2 cancer cell line, and embryonic development of Zebrafish. We demonstrated the activity of 4-AN against selected bacteria and Candida spp. The MIC ranging from 4?µg/ml to 125?µg/ml proved effective in inhibition of formation of hyphae and cell aggregation in Candida, which was demonstrated at the cytological level. Noteworthy, 4-AN was found to inhibit the CK2 kinase with moderate potency. Moreover, at low concentrations, it did not exert any evident toxic effects on human erythrocytes, Caco-2 cells, or Zebrafish embryos. 4-AN can be a potential candidate as a novel drug against Candida infections. 相似文献
129.
Juan R. Ordoñana Juan F. Sánchez Romera Lucía Colodro-Conde Eduvigis Carrillo Francisca González-Javier Juan J. Madrid-Valero José J. Morosoli-García Francisco Pérez-Riquelme José M. Martínez-Selva 《Gaceta sanitaria / S.E.S.P.A.S》2018,32(1):92-95
Genetically informative designs and, in particular, twin studies, are the most widely used methodology to analyse the relative contribution of genetic and environmental factors to inter-individual variability. These studies basically compare the degree of phenotypical similarity between monozygotic and dizygotic twin pairs. In addition to the traditional estimate of heritability, this kind of registry enables a wide variety of analyses which are unique due to the characteristics of the sample. The Murcia Twin Registry is population-based and focused on the analysis of health-related behaviour. The observed prevalence of health problems is comparable to that of other regional and national reference samples, which guarantees its representativeness. Overall, the characteristics of the Registry facilitate developing various types of research as well as genetically informative designs, and collaboration with different initiatives and consortia. 相似文献
130.
Pedro F. Sánchez-López Ignacio Ruiz-Arrondo Heiko Kotter Francisco Pacheco Martínez Manuel Segovia Hernández M. Elisa Gómez Campoy 《Gaceta sanitaria / S.E.S.P.A.S》2018,32(2):181-183
Historically, no black fly (Diptera: Simuliidae) nuisance has been reported in the Murcia Region. Back in September 2016 the Ojós City Council has contacted the Regional Public Health General Directorate for help regarding a local insect nuisance, most probably based on mosquitoes. After sampling with a BG-sentinel 2 trap, collecting adult specimens with an entomological aspirator, and collect larvae and pupae on submerged giant cane stalks at the river, it turned out that Simulium sergenti was the insect species causing the nuisance. This species is not considered particularly anthropophilic; therefore, a low vector risk for human health was considered. However, the high fly density impaired the life quality of the people at the village. A management plan was recommended, treating the river with Bacillus thuringiensis var israelensis. 相似文献