全文获取类型
收费全文 | 2023篇 |
免费 | 103篇 |
国内免费 | 17篇 |
专业分类
耳鼻咽喉 | 21篇 |
儿科学 | 99篇 |
妇产科学 | 31篇 |
基础医学 | 191篇 |
口腔科学 | 47篇 |
临床医学 | 220篇 |
内科学 | 440篇 |
皮肤病学 | 60篇 |
神经病学 | 118篇 |
特种医学 | 274篇 |
外科学 | 249篇 |
综合类 | 59篇 |
预防医学 | 109篇 |
眼科学 | 18篇 |
药学 | 107篇 |
中国医学 | 7篇 |
肿瘤学 | 93篇 |
出版年
2024年 | 4篇 |
2023年 | 13篇 |
2022年 | 12篇 |
2021年 | 22篇 |
2020年 | 17篇 |
2019年 | 21篇 |
2018年 | 51篇 |
2017年 | 27篇 |
2016年 | 36篇 |
2015年 | 39篇 |
2014年 | 61篇 |
2013年 | 77篇 |
2012年 | 109篇 |
2011年 | 102篇 |
2010年 | 90篇 |
2009年 | 87篇 |
2008年 | 107篇 |
2007年 | 81篇 |
2006年 | 85篇 |
2005年 | 76篇 |
2004年 | 82篇 |
2003年 | 70篇 |
2002年 | 59篇 |
2001年 | 45篇 |
2000年 | 36篇 |
1999年 | 30篇 |
1998年 | 59篇 |
1997年 | 55篇 |
1996年 | 71篇 |
1995年 | 51篇 |
1994年 | 48篇 |
1993年 | 50篇 |
1992年 | 16篇 |
1991年 | 15篇 |
1990年 | 21篇 |
1989年 | 39篇 |
1988年 | 38篇 |
1987年 | 37篇 |
1986年 | 37篇 |
1985年 | 25篇 |
1984年 | 17篇 |
1983年 | 11篇 |
1982年 | 23篇 |
1981年 | 15篇 |
1980年 | 8篇 |
1978年 | 7篇 |
1977年 | 13篇 |
1976年 | 12篇 |
1975年 | 15篇 |
1972年 | 4篇 |
排序方式: 共有2143条查询结果,搜索用时 15 毫秒
81.
82.
Fufa D. Bari Satya Parida Tesfaalem Tekleghiorghis Aldo Dekker Abraham Sangula Richard Reeve Daniel T. Haydon David J. Paton Mana Mahapatra 《Vaccine》2014
Vaccine strain selection for emerging foot-and-mouth disease virus (FMDV) outbreaks in enzootic countries can be addressed through antigenic and genetic characterisation of recently circulating viruses. A total of 56 serotype A FMDVs isolated between 1998 and 2012, from Central, East and North African countries were characterised antigenically by virus neutralisation test using antisera to three existing and four candidate vaccine strains and, genetically by characterising the full capsid sequence data. A Bayesian analysis of the capsid sequence data revealed the viruses to be of either African or Asian topotypes with subdivision of the African topotype viruses into four genotypes (Genotypes I, II, IV and VII). The existing vaccine strains were found to be least cross-reactive (good matches observed for only 5.4–46.4% of the sampled viruses). Three bovine antisera, raised against A-EA-2007, A-EA-1981 and A-EA-1984 viruses, exhibited broad cross-neutralisation, towards more than 85% of the circulating viruses. Of the three vaccines, A-EA-2007 was the best showing more than 90% in-vitro cross-protection, as well as being the most recent amongst the vaccine strains used in this study. It therefore appears antigenically suitable as a vaccine strain to be used in the region in FMD control programmes. 相似文献
83.
The communication between tumor stromal and parenchymal cells provides an insight to tumor progression. One of the main elements of the stroma, a major contributor to the extracellular environment of tumors, is carcinoma‐associated fibroblasts. They can originate from either normal fibroblasts in the immediate vicinity of the tumor or from circulating bone marrow–derived mesenchymal stem cells. These myofibroblasts can arise locally from an endothelial–mesenchymal transformation at the invasive edge of the cancer and are physically associated with carcinoma cells, that is, in the development of high‐grade malignancies and poor prognosis. These carcinoma‐associated fibroblasts feed the epithelial tumor cells in a host–parasite relationship establishing its role in head and neck squamous cell carcinoma progression. 相似文献
84.
Alessia Cruciata Lorenzo Volpicelli Silvia Di Bari Giancarlo Iaiani Bruno Cirillo Francesco Pugliese Daniela Pellegrino Gioacchino Galardo Gloria Taliani 《Viruses》2022,14(3)
This monocentric, retrospective, two-stage observational study aimed to recognize the risk factors for a poor outcome in patients hospitalized with SARS-CoV-2 infection, and to develop and validate a risk score that identifies subjects at risk of worsening, death, or both. The data of patients with SARS-CoV-2 infection during the first wave of the pandemic were collected and analyzed as a derivation cohort. Variables with predictive properties were used to construct a prognostic score, which was tried out on a validation cohort enrolled during the second wave. The derivation cohort included 494 patients; the median age was 62 and the overall fatality rate was 22.3%. In a multivariable analysis, age, oxygen saturation, neutrophil-to-lymphocyte ratio, C-reactive protein and lactate dehydrogenase were independent predictors of death and composed the score. A cutoff value of 3 demonstrated a sensitivity (Se), specificity (Sp), positive predictive value (PPV) and negative predictive value (NPV) of 93.5%, 68.5%, 47.4% and 97.2% for death, and 84.9%, 84.5%, 79.6% and 87.9% for worsening, respectively. The validation cohort included 415 subjects. The score application showed a Se, Sp, PPV and NPV of 93.4%, 61.6%, 29.5% and 98.1% for death, and 81%, 76.3%, 72.1% and 84.1% for worsening, respectively. We propose a new clinical, easy and reliable score to predict the outcome in hospitalized SARS-CoV-2 patients. 相似文献
85.
The effect of iron deficiency anemia on the development of atherosclerosis was investigated in chicks. The control group of birds were fed a basal diet, the atherosclerosis group received 1% cholesterol. The lipid content of the aortas of the chicks in atherosclerosis and atherosclerosis-anemia group also developed anemia of appreciable severity in 12 weeks. Hemoglobin and PCV were taken as the index of anemia, while the lipid constituents were determined in plasma and aortic tissue for atherosclerosis. Hypercholesterolemia of almost equal severity occurred in both atherosclerosis and atherosclerosis-anemia groups. The abnormal rise of cholesterol and other lipid material in the aortas of the atherosclerosis and atherosclerosis-anemia groups of birds indicates that iron deficiency anemia did not markedly affect the development of atheroslcerosis; it did not offer any protection in chickens and, in fact, a slight potentiating effect was observed. 相似文献
86.
A novel guidewire‐integrated embolic protection filter device with a handy‐folding system: In vitro and in vivo performance assessment
下载免费PDF全文
![点击此处可从《Catheterization and cardiovascular interventions》网站下载免费的PDF全文](/ch/ext_images/free.gif)
87.
Francesco Orso Alessandra Pratesi Andrea Herbst Anna Chiara Baroncini Francesca Bacci Gabriele Ciuti Andrea Berni Camilla Tozzetti Carlo Nozzoli Alberto Moggi Pignone Loredana Poggesi Luciano Gabbani Mauro Di Bari Francesco Fattirolli Massimo Milli Andrea Ungar Niccol Marchionni Samuele Baldasseroni 《老年心脏病学杂志》2021,18(6):407-415
88.
Juliana Maier Camila Silveira Sfreddo Ana Paula Pereira Reiniger Karla Zanini Kantorski Ulf ME Wikesj Carlos Heitor Cunha Moreira 《International dental journal》2021,71(2):127
BackgroundPeriodontal disease is a major cause of tooth loss. Few studies have evaluated the residual area of the periodontal ligament in extracted teeth and, to the best of our knowledge, none from Latin America have done so regarding indications for extraction. The aim of this study was to evaluate the residual periodontal ligament (RPL) with respect to indication for extraction in a sample of teeth from a Brazilian Public Health Service district.Materials and methodsAll teeth extracted within the Public Health Service district of Santa Maria, Brazil, over a 5-month period were requested for analysis. A total of 414 teeth eligible for measurement were stained and evaluated for RPL using a stereo microscope. Participating Public Health Service dentists completed a questionnaire detailing demographic variables and indication for each extracted tooth. The percentage of RPL was determined for each tooth. Comparisons of RPL between teeth extracted on periodontal versus other indications were made using the Mann-Whitney test.ResultsRPL averaged 34.8% for teeth extracted on periodontal indications versus 79.5% for other teeth (P ≤ 0.001). When considering teeth with an RPL ≥ 30% as possible to maintain, 189 (76%) of the teeth extracted on periodontal indications could have been maintained. When RPL cut-off limits of ≥ 40% or ≥ 50% are applied, 93 (37%) and 43 (17%) teeth, respectively, could have been maintained.ConclusionThis study suggests that strictly based on RPL, a large number of teeth extracted on periodontal indications conceivably could be maintained.Key words: Cross-sectional studies, Prognosis, Tooth extraction, Tooth loss 相似文献
89.
Patience ME Ocansey Irene A Kretchy Genevieve C Aryeetey Kofi Agyabeng Justice Nonvignon 《Ghana medical journal》2021,55(3):173
ObjectiveThis study assessed levels of anxiety, depression, and stress among family caregivers of children and adolescents with mental disorders in Ghana and the implication on medication adherence.DesignA cross-sectional study.SettingThe study was conducted at the outpatient departments of the three main public psychiatric hospitals in Ghana.ParticipantsTwo hundred and ten non-paid family caregivers of children and adolescents with mental disorders were recruited for this study.Main Outcome MeasureThe study assessed symptoms of anxiety, depression and stress among the caregivers and estimated caregiver-reported medication adherence.ResultsAbout 56.2%, 66.2% and 78% of the caregivers experienced severe anxiety, severe depression and moderate to severe stress symptoms respectively. From the multiple logistic regression model, while anxiety was significantly affected by religion and education, depression was influenced by sex, age, marital status, proximity to facility, and employment status. Female caregivers had about four times higher odds of being depressed compared to male caregivers (aOR: 3.81, 95% CI: 1.66 – 8.75). The caregiver-reported medication adherence was 11.9%. Anxiety was significantly predictive of medication adherence.ConclusionMost family caregivers of children and adolescents with mental disorders experienced symptoms of anxiety, depression and stress with anxiety having implications for medication adherence. The study findings underscore the need to consider psychological characteristics of caregivers and the provision of mental health support for them, as part of the routine health care for children and adolescents with mental disorders.FundingNone indicated 相似文献
90.
Raffaella Marcheselli Alessia Bari Tamar Tadmor Luigi Marcheselli Maria Christina Cox Robel Papotti Angela Ferrari Luca Baldini Paolo Gobbi Ilana Levy Giuseppe Pugliese Massimo Federico Aaron Polliack Samantha Pozzi Stefano Sacchi 《Hematological oncology》2020,38(4):439-445
The main purpose of this study was to assess whether it is possible to improve the prognostic impact of international prognostic index (IPI) score by combining it with peripheral blood counts. Thus, we evaluated the prognostic power of lymphocyte, neutrophil, and monocyte counts in 520 patients with diffuse large B cell lymphoma treated with R-CHOP, confirming that these parameters have a strong impact on overall survival (OS). Using revised IPI (R-IPI), 44% of patients were categorized as poor-risk and showed an OS at 5 years of 46%. As OS at 5 years of the 520 patients is 67%, it is clearly evident that R-IPI tends to overestimate the proportion of patients with poor prognosis. Accordingly, in an attempt to improve the discriminating power of R-IPI, we evaluated and compared three different scores by combining the neutrophil lymphocyte ratio (NLR) and absolute monocyte count (AMC) with the following values: (a) IPI score 3-5, (b) age > 60 years and performance status, (c) age ≥ 65 years and LDH > ULN. The three indexes studied, had a similar 5 years OS for the high-risk group (46%-52%), but the proportion of patients classified as poor-risk were 37%, 20%, and 32%, respectively, which are lower than 44% identified with R-IPI. Thus, while R-IPI overestimates the number of high-risk patients, after applying our models, it is possible to recognize patients who are truly at high-risk. Of the three scores, the most accurate appears to be that based on NLR, AMC, LDH > ULN and age ≥ 65 years, which identifies 32% of high-risk patients, correlating well with what is seen in clinical practice. 相似文献