全文获取类型
收费全文 | 17838篇 |
免费 | 1111篇 |
国内免费 | 138篇 |
专业分类
耳鼻咽喉 | 112篇 |
儿科学 | 493篇 |
妇产科学 | 370篇 |
基础医学 | 2877篇 |
口腔科学 | 347篇 |
临床医学 | 1480篇 |
内科学 | 4520篇 |
皮肤病学 | 301篇 |
神经病学 | 1817篇 |
特种医学 | 449篇 |
外科学 | 1332篇 |
综合类 | 48篇 |
一般理论 | 5篇 |
预防医学 | 1395篇 |
眼科学 | 208篇 |
药学 | 1330篇 |
1篇 | |
中国医学 | 61篇 |
肿瘤学 | 1941篇 |
出版年
2024年 | 69篇 |
2023年 | 208篇 |
2022年 | 392篇 |
2021年 | 677篇 |
2020年 | 409篇 |
2019年 | 541篇 |
2018年 | 583篇 |
2017年 | 484篇 |
2016年 | 547篇 |
2015年 | 596篇 |
2014年 | 752篇 |
2013年 | 1000篇 |
2012年 | 1621篇 |
2011年 | 1619篇 |
2010年 | 891篇 |
2009年 | 799篇 |
2008年 | 1307篇 |
2007年 | 1205篇 |
2006年 | 1153篇 |
2005年 | 996篇 |
2004年 | 907篇 |
2003年 | 758篇 |
2002年 | 652篇 |
2001年 | 84篇 |
2000年 | 47篇 |
1999年 | 94篇 |
1998年 | 122篇 |
1997年 | 99篇 |
1996年 | 93篇 |
1995年 | 50篇 |
1994年 | 44篇 |
1993年 | 49篇 |
1992年 | 28篇 |
1991年 | 25篇 |
1990年 | 23篇 |
1989年 | 9篇 |
1988年 | 12篇 |
1987年 | 17篇 |
1986年 | 10篇 |
1985年 | 7篇 |
1984年 | 17篇 |
1983年 | 11篇 |
1982年 | 12篇 |
1981年 | 10篇 |
1980年 | 9篇 |
1979年 | 6篇 |
1978年 | 5篇 |
1975年 | 5篇 |
1973年 | 10篇 |
1971年 | 4篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Luciana Tornquist Debora Tornquist Letícia B. Schneiders Silvia I. R. Franke Jane D. P. Renner Czane P. Reuter 《Arquivos brasileiros de cardiologia》2022,119(2):236
BackgroundCardiometabolic risk has been shown to be inversely associated with cardiorespiratory fitness (CRF) and positively associated with body mass index (BMI).ObjectiveOur objective was to analyze the association of cardiometabolic risk factors with combined BMI and CRF in schoolchildren from a city in southern Brazil.MethodsCross-sectional study with a sample of 1252 schoolchildren aged seven to 17 years. Total cholesterol (TC), HDL-c, LDL-c, triglycerides (TG), systolic (SBP) and diastolic blood pressure (DBP) were evaluated. CRF and BMI were grouped into one variable and the schoolchildren were classified as eutrophic/fit, eutrophic/unfit, overweight-obese/fit, and overweight-obese/unfit. Crude and adjusted analyzes were performed using Poisson Regression and an alpha of 0.05 was adopted.ResultsOverweight-obese and fit schoolchildren showed a prevalence ratio (PR) of 1.50 (1.04 – 2.16) for altered TG, 3.05 (2.05 – 4.54) for elevated SBP, and 2.70 (1.87 – 3.88) for elevated DBP. Overweight-obese and unfit schoolchildren showed a PR for high TC of 1.24 (1.11 – 1.39) and 1.51(1.11 – 2.04) for low HDL levels. In addition, they had a risk of 2.07 (1.60 – 2.69) for altered TG, 3.36 (2.31 – 4.60) for elevated SBP and 2.42 (1.76 – 3.32) for altered DBP.ConclusionBMI played a central role in the association with risk and CRF was shown to attenuate the association between risk factors and obesity. Overweight-obese children and adolescents had a higher cardiometabolic risk, but the effect size was larger among the unfit. 相似文献
52.
Silvia Bianchi Maria Gori Clara Fappani Giulia Ciceri Marta Canuti Daniela Colzani Marco Dura Mara Terraneo Anna Lamberti Melissa Baggieri Sabrina Senatore Marino Faccini Fabio Magurano Elisabetta Tanzi Antonella Amendola 《Viruses》2022,14(5)
Despite the existence of an effective live-attenuated vaccine, measles can appear in vaccinated individuals. We investigated breakthrough measles cases identified during our surveillance activities within the measles/rubella surveillance network (MoRoNet) in Milan and surrounding areas (Northern Italy). Between 2017 and 2021, we confirmed measles virus (genotypes B3 or D8) infections in 653 patients and 51 of these (7.8%) were vaccinees. Among vaccinated individuals whose serum was available, a secondary failure was evidenced in 69.4% (25/36) of cases while 11 patients (30.6%) were non-responders. Non-responders were more frequently hospitalized and had significantly lower Ct values in both respiratory and urine samples. Median age and time since the last immunization were similar in the two groups. Importantly, we identified onward transmissions from vaccine failure cases. Vaccinees were involved in 20 outbreaks, in 10 of them they were able to transmit the virus, and in 8 of them, they were the index case. Comparing viral hemagglutinin sequences from vaccinated and non-vaccinated subjects did not show a specific mutation pattern. These results suggest that vaccination failure was likely due to the poor immune response of single individuals and highlights the importance of identifying breakthrough cases and characterizing their clinical and virologic profiles. 相似文献
53.
Medial prefrontal cortex (mPfC) activity represents information about the state of the world, including present behavior, such as decisions, and the immediate past, such as short-term memory. Unknown is whether information about different states of the world are represented in the same mPfC neural population and, if so, how they are kept distinct. To address this, we analyze here mPfC population activity of male rats learning rules in a Y-maze, with self-initiated choice trials to an arm end followed by a self-paced return during the intertrial interval (ITI). We find that trial and ITI population activity from the same population fall into different low-dimensional subspaces. These subspaces encode different states of the world: multiple features of the task can be decoded from both trial and ITI activity, but the decoding axes for the same feature are roughly orthogonal between the two task phases, and the decodings are predominantly of features of the present during the trial but features of the preceding trial during the ITI. These subspace distinctions are carried forward into sleep, where population activity is preferentially reactivated in post-training sleep but differently for activity from the trial and ITI subspaces. Our results suggest that the problem of interference when representing different states of the world is solved in mPfC by population activity occupying different subspaces for the world states, which can be independently decoded by downstream targets and independently addressed by upstream inputs.SIGNIFICANCE STATEMENT Activity in the medial prefrontal cortex plays a role in representing the current and past states of the world. We show that during a maze task, the activity of a single population in medial prefrontal cortex represents at least two different states of the world. These representations were sequential and sufficiently distinct that a downstream population could separately read out either state from that activity. Moreover, the activity representing different states is differently reactivated in sleep. Different world states can thus be represented in the same medial prefrontal cortex population but in such a way that prevents potentially catastrophic interference between them. 相似文献
54.
Silvia Herrero-Cfreces Franois Mougeot Tarja Sironen Hermann Meyer Ruth Rodríguez-Pastor Juan Jos Luque-Larena 《Emerging infectious diseases》2022,28(6):1294
We screened 526 wild small mammals for zoonotic viruses in northwest Spain and found hantavirus in common voles (Microtus arvalis) (1.5%) and high prevalence (48%) of orthopoxvirus among western Mediterranean mice (Mus spretus). We also detected arenavirus among small mammals. These findings suggest novel risks for viral transmission in the region. 相似文献
55.
Andreas Hoefer Silvia Herrera-Len Lucas Domínguez Maria Ordobs Gavín Beatriz Romero Ximena Belen Araujo Piedra Cristina Sobrino Calzada María Jos Uría Gonzlez Laura Herrera-Len Case Study Investigation Group 《Emerging infectious diseases》2022,28(6):1257
Toxigenic Corynebacterium ulcerans is as an emerging zoonotic agent of diphtheria. We describe the zoonotic transmission of diphtheria caused by toxigenic C. ulcerans from domestic animals in Spain, confirmed by core-genome multilocus sequence typing. Alongside an increasing number of recent publications, our findings highlight the public health threat posed by diphtheria reemergence. 相似文献
56.
Zhang Xu Jung-Hyun Choi David L. Dai Jun Luo Reese Jalal Ladak Qian Li Yimeng Wang Christine Zhang Shane Wiebe Alex C. H. Liu Xiaozhuo Ran Jiaqi Yang Parisa Naeli Aitor Garzia Lele Zhou Niaz Mahmood Qiyun Deng Mohamed Elaish Rongtuan Lin Lara K. Mahal Tom C. Hobman Jerry Pelletier Tommy Alain Silvia M. Vidal Thomas Duchaine Mohammad T. Mazhab-Jafari Xiaojuan Mao Seyed Mehdi Jafarnejad Nahum Sonenberg 《Proceedings of the National Academy of Sciences of the United States of America》2022,119(32)
57.
Shashi Bhushan Kumar Shanvanth R. Arnipalli Priyanka Mehta Silvia Carrau Ouliana Ziouzenkova 《Nutrients》2022,14(14)
Iron deficiency anemia (IDA) has reached epidemic proportions in developing countries and has become a major global public health problem, affecting mainly 0–5-year-old children and young women of childbearing age, especially during pregnancy. Iron deficiency can lead to life-threatening loss of red blood cells, muscle function, and energy production. Therefore, the pathogenic features associated with IDA are weakness and impaired growth, motor, and cognitive performance. IDA affects the well-being of the young generation and the economic advancement of developing countries, such as India. The imbalance between iron intake/absorption/storage and iron utilization/loss culminates into IDA. However, numerous strategic programs aimed to increase iron intake have shown that improvement of iron intake alone has not been sufficient to mitigate IDA. Emerging critical risk factors for IDA include a composition of cultural diets, infections, genetics, inflammatory conditions, metabolic diseases, dysbiosis, and socioeconomic parameters. In this review, we discuss numerous IDA mitigation programs in India and their limitations. The new multifactorial mechanism of IDA pathogenesis opens perspectives for the improvement of mitigation programs and relief of IDA in India and worldwide. 相似文献
58.
Giovanni Corsetti Claudia Romano Silvia Codenotti Evasio Pasini Alessandro Fanzani Francesco S. Dioguardi 《Nutrients》2022,14(14)
Background: Excess body adipose tissue accumulation is a common and growing health problem caused by an unbalanced diet and/or junk food. Although the effects of dietary fat and glucose on lipid metabolism regulation are well known, those of essential amino acids (EAAs) have been poorly investigated. Our aim was to study the influence of a special diet containing all EAAs on retroperitoneal white adipose tissue (rpWAT) and interscapular brown adipose tissue (BAT) of mice. Methods: Two groups of male Balb/C mice were used. The first was fed with a standard diet. The second was fed with an EAAs-rich diet (EAARD). After 3 weeks, rpWAT and BAT were removed and prepared for subsequent immunohistochemical analysis. Results: EAARD, although consumed significantly less, moderately reduced body weight and BAT, but caused a massive reduction in rpWAT. Conversely, the triceps muscle increased in mass. In rpWAT, the size of adipocytes was very small, with increases in leptin, adiponectin and IL-6 immunostaining. In BAT, there was a reduction in lipid droplet size and a simultaneous increase in UCP-1 and SIRT-3. Conclusions: A diet containing a balanced mixture of free EAA may modulate body adiposity in mice, promoting increased thermogenesis. 相似文献
59.
Marioni G Blandamura S Calgaro N Ferraro SM Stramare R Staffieri A De Filippis C 《Acta oto-laryngologica》2005,125(6):678-682
Clinical evidence of non-lymphatic distant metastasis has been reported in approximately 10% of cases of head and neck squamous cell carcinoma (HNSCC). The lungs are the commonest site of distant metastasis of HNSCC, followed by the bones, liver and skin. A 65-year-old male underwent supraglottic laryngectomy and left modified neck dissection for a carcinoma of the laryngeal surface of the epiglottis extending to both false cords. Eight months later the patient underwent right radical modified neck dissection for hypodermal metastatic disease involving the underlying (sternocleidomastoid) muscle. Thirty-two months later, surgical excision of a lesion in the right gluteus maximus muscle was performed. Histological study diagnosed a muscular metastasis with the same morphological aspect as the laryngeal carcinoma. The patient showed no evidence of cervical or distant recurrence at follow-up after 13 months. Although skeletal muscles represent approximately 50% of total body mass and receive a large proportion of total cardiac output, haematogenous metastases to skeletal muscle are extremely uncommon. Most skeletal muscle metastases are of pulmonary origin. Distant skeletal muscle metastasis from HNSCC is an extremely rare occurrence. Treatment options, depending upon the clinical setting, include observation, radiotherapy, chemotherapy and excision; these approaches rarely alter the patient outcome. The prognosis associated with skeletal muscle metastasis is thought to be poor, consistent with the fact that it generally occurs as a feature of systemic spread. 相似文献
60.