全文获取类型
收费全文 | 4873篇 |
免费 | 324篇 |
国内免费 | 21篇 |
专业分类
耳鼻咽喉 | 20篇 |
儿科学 | 150篇 |
妇产科学 | 111篇 |
基础医学 | 726篇 |
口腔科学 | 128篇 |
临床医学 | 376篇 |
内科学 | 1163篇 |
皮肤病学 | 217篇 |
神经病学 | 545篇 |
特种医学 | 45篇 |
外科学 | 412篇 |
综合类 | 21篇 |
预防医学 | 413篇 |
眼科学 | 145篇 |
药学 | 376篇 |
中国医学 | 33篇 |
肿瘤学 | 337篇 |
出版年
2024年 | 3篇 |
2023年 | 39篇 |
2022年 | 91篇 |
2021年 | 178篇 |
2020年 | 102篇 |
2019年 | 169篇 |
2018年 | 187篇 |
2017年 | 131篇 |
2016年 | 149篇 |
2015年 | 157篇 |
2014年 | 221篇 |
2013年 | 256篇 |
2012年 | 450篇 |
2011年 | 433篇 |
2010年 | 246篇 |
2009年 | 192篇 |
2008年 | 345篇 |
2007年 | 302篇 |
2006年 | 279篇 |
2005年 | 293篇 |
2004年 | 259篇 |
2003年 | 229篇 |
2002年 | 239篇 |
2001年 | 15篇 |
2000年 | 16篇 |
1999年 | 41篇 |
1998年 | 31篇 |
1997年 | 29篇 |
1996年 | 24篇 |
1995年 | 15篇 |
1994年 | 8篇 |
1993年 | 12篇 |
1992年 | 11篇 |
1991年 | 8篇 |
1990年 | 8篇 |
1989年 | 2篇 |
1988年 | 3篇 |
1987年 | 7篇 |
1986年 | 9篇 |
1983年 | 2篇 |
1982年 | 5篇 |
1981年 | 4篇 |
1980年 | 2篇 |
1978年 | 3篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有5218条查询结果,搜索用时 15 毫秒
41.
Garcia-Olivé I Prats Bardají MS Calvo Pascual S Sánchez Berenguer D Valverde Forcada E Ruiz-Manzano J 《Archivos de bronconeumología》2008,44(3):170-172
Takayasu arteritis is an inflammatory disease that affects large vessels, especially the aorta and its branches. The clinical features of the disease depend on which arteries are affected. Although pulmonary artery involvement is common, only rarely is this the main clinical manifestation. We describe the case of a young woman with dyspnea who had severe pulmonary hypertension secondary to Takayasu arteritis of the pulmonary artery. She was administered corticosteroid (methylprednisolone) and immunosuppressant (azathioprine) therapy and a stent was implanted in the left pulmonary artery. Both hemodynamic and clinical signs improved. 相似文献
42.
Tannistha Nandi Matthew T.G. Holden Xavier Didelot Kurosh Mehershahi Justin A. Boddey Ifor Beacham Ian Peak John Harting Primo Baybayan Yan Guo Susana Wang Lee Chee How Bernice Sim Angela Essex-Lopresti Mitali Sarkar-Tyson Michelle Nelson Sophie Smither Catherine Ong Lay Tin Aw Chua Hui Hoon Stephen Michell David J. Studholme Richard Titball Swaine L. Chen Julian Parkhill Patrick Tan 《Genome research》2015,25(1):129-141
Burkholderia pseudomallei (Bp) is the causative agent of the infectious disease melioidosis. To investigate population diversity, recombination, and horizontal gene transfer in closely related Bp isolates, we performed whole-genome sequencing (WGS) on 106 clinical, animal, and environmental strains from a restricted Asian locale. Whole-genome phylogenies resolved multiple genomic clades of Bp, largely congruent with multilocus sequence typing (MLST). We discovered widespread recombination in the Bp core genome, involving hundreds of regions associated with multiple haplotypes. Highly recombinant regions exhibited functional enrichments that may contribute to virulence. We observed clade-specific patterns of recombination and accessory gene exchange, and provide evidence that this is likely due to ongoing recombination between clade members. Reciprocally, interclade exchanges were rarely observed, suggesting mechanisms restricting gene flow between clades. Interrogation of accessory elements revealed that each clade harbored a distinct complement of restriction-modification (RM) systems, predicted to cause clade-specific patterns of DNA methylation. Using methylome sequencing, we confirmed that representative strains from separate clades indeed exhibit distinct methylation profiles. Finally, using an E. coli system, we demonstrate that Bp RM systems can inhibit uptake of non-self DNA. Our data suggest that RM systems borne on mobile elements, besides preventing foreign DNA invasion, may also contribute to limiting exchanges of genetic material between individuals of the same species. Genomic clades may thus represent functional units of genetic isolation in Bp, modulating intraspecies genetic diversity.Burkholderia pseudomallei (Bp) is the causative agent of melioidosis, a serious infectious disease of humans and animals and a leading cause of community-acquired sepsis and pneumonia in endemic regions (Currie et al. 2010). Initially thought to be confined to Southeast Asia and Northern Australia, the prevalence of Bp appears to be spreading (Wiersinga et al. 2012), and Bp has been designated a biothreat select agent in the United States. Bp can persist in extreme environmental conditions and can infect several plant and animal hosts, including birds, dolphins, and humans (Wuthiekanun et al. 1995; Howard and Inglis 2003; Sprague and Neubauer 2004; Larsen et al. 2013). Treatment of clinical melioidosis is challenging because the bacterium is inherently resistant to many antibiotics, and Bp infections can persist in humans for more than a decade (Hayden et al. 2012; Wiersinga et al. 2012).The Bp genome comprises one of the largest and most complex bacterial genomes sequenced to date. Consisting of two large circular replicons (chromosomes) with a combined 7.2-Mb genome size (Holden et al. 2004), it contains a rich arsenal of genes related to virulence (e.g., Type III and Type VI secretion systems, polysaccharide biosynthesis clusters), metabolic pathways, and environmental adaptation (Wiersinga et al. 2012). Besides conserved regions, accessory genes on mobile elements and genomic islands may also contribute to phenotypic and clinical differences in microbial behavior (Currie et al. 2000; Sim et al. 2008). Analysis of the Bp genome has revealed previously unknown toxins and mechanisms of antibiotic resistance (Chantratita et al. 2011; Cruz-Migoni et al. 2011).Most large-scale studies of Bp genetic diversity to date have analyzed strains using multilocus sequence typing (MLST). These studies have suggested a high degree of genetic variability between Bp strains and related Burkholderia species (Cheng et al. 2008), and have shown that Bp strains belonging to different sequence types (STs) can often coexist in the same locale and sometimes even within the same sample (Pitt et al. 2007; Wuthiekanun et al. 2009). However, due to the limited number of genes analyzed by MLST, these studies cannot comment on the global proportion of genetic material shared between strains of different STs nor on the relative contribution of recombination, mutation, and horizontal gene transfer on intraspecies genetic diversity. Moreover, although previous studies have applied whole-genome sequencing (WGS) to study global patterns of Bp genetic heterogeneity and evolution, earlier Bp WGS reports have been confined to a limited number of isolates (10–12) derived from diverse geographical regions (Nandi et al. 2010), where geophysical barriers likely limit the propensity of the analyzed strains to exchange genetic material. To achieve a comprehensive understanding of genetic variation among closely related Bp strains, WGS analysis of much larger strain panels, ideally performed on strains isolated from a common region and belonging to the same (or closely related) ST groups, is required.In this study, we attempted to fill this important knowledge gap by performing WGS on 106 Bp strains drawn from a restricted Asian locale (Singapore and Malaysia). The WGS data, exceeding previous Bp WGS studies by 10-fold, enabled us to identify specific genomic clades of Bp, molecular features of Bp recombination at the whole-genome level, and accessory genome features contributing to recombination and horizontal gene transfer. We found a consistent pattern of genetic separation correlating with MLST, recombination haplotypes, shared accessory genes, and restriction modification (RM) systems. We provide evidence that restriction modification, beyond its role as defense against foreign DNA invasion, may have also partitioned the Bp species by restricting gene flow, resulting in the other observed correlations. Because RM systems are widely dispersed through the bacterial kingdom, it is possible that similar principles may apply to other bacterial species, implicating a potential role for epigenetic barriers as a driver of early incipient speciation. 相似文献
43.
Susana Gavidia‐Payne Bianca Denny Kate Davis Andrew Francis Merv Jackson 《Clinical Psychologist》2015,19(3):111-121
The substantial focus of resilience research on childhood well‐being has resulted in limited knowledge regarding other aspects of resilience in families, such as that of parents. Informed by literature in childhood and family resilience, in this review, we progress conceptual understanding by focusing on parental resilience. The definition of parental resilience, as the capacity of parents to deliver a competent and quality level of parenting to children despite the presence of risk factors, is offered here as a worthwhile framework through which to explore variables thought to contribute to resilience among parents. A conceptual model is proposed whereby parental psychological well‐being and self‐efficacy, family functioning, and social connectedness are specifically addressed, with each posited as playing an important role in parents’ ability to deliver high‐quality parenting. In addition to these factors, how parents accommodate adversity and find meaning in their everyday lives within their families is hypothesised to be an important process in understanding parental resilience. 相似文献
44.
Susana Rodríguez Villa María Teresa Suárez Muñiz Ricardo De Dios del Valle Crisanto Alonso Álvarez 《Enfermería clínica》2018,28(1):44-48
Aim
To compare the evaluation of retinographies by a teleophthalmology nurse and primary care physicians (PCP) with an ophthalmologist referral hospital (gold standard).Methods
Cross-sectional study on a random sample of 337 patients on the teleophthalmology programme from January 2010 to January 2015. We analyzed the diagnostic evaluation (whether or not it presented findings of RD) and the therapeutic assessment (whether or not referral to the opthalmology department was needed) which were conducted independently on the sample retinographies by the PCP, a nurse and an ophthalmologist (gold standard). Reliability and concordance between the gold standard and the PCP and the nurse were checked and the statistical analyses were supported using SPSSv.23.00 software and diagnostic test reliability calculators (EPIDAT 4.1).Results
In the diagnosis of RD, the nurse presented: sensitivity (S): 0.96; specificity (Sp): 0.89; PPV: 0.58; NPV: 0.99; Kappa index: 0.67 and PCP: S: 0.98; Sp: 0.99; PPV: 0.96; NPV: 0.99; Kappa index: 0.96.In the referral to ophthalmology assessed by the nurse: S: 0.83; Sp: 0.83; PPV: 0.51; NPV: 0.96; Kappa Index: 0.53 and PCP: S: 0.62; Sp: 0.76; PPV: 0.36; NPV: 0.90; Kappa index: 0.29.Conclusions
A nursing teleophthalmology programme could perform population screening for RD with the same quality as PCP. This would increase coverage, in addition to providing better use of resources by avoiding intermediate patient appointments through PCP and increased health savings. 相似文献45.
Pedro M. Félix Susana Marta Almeida Cristiana Franco António Bugalho Almeida Carlos Lopes Maria Inês Claro 《International journal of environmental health research》2015,25(1):67-80
Occupational exposure to lead (Pb) requires continuous surveillance to assure, as much as possible, safe and healthful working conditions. This study addresses the suitability of assessing Pb exposure in relevant workers using their exhaled breath condensate (EBC). This study enrolled workers of two different Pb processing industries characterized by moderate and high Pb exposure levels in the work environment, and a group of non-exposed individuals working in offices who served as baseline for Pb exposure. The EBC-Pb of workers reflected the Pb levels in the work environment of all three settings, although the relationship with B-Pb was not clear. The lack of correlation between EBC-Pb and B-Pb most probably indicates the time lag for Pb to enter in the two body pools. The EBC-Pb seems to reflect immediate exposure, providing a prompt signature of Pb in the environmental that may interact directly with the organ. By delivering short-term evaluation of exposure, EBC-Pb represents a clear advantage in biomonitoring and may become an interesting tool for estimating organ burden. 相似文献
46.
Christiane Bergamasco RD Lilian Mika Horie RD Raquel Susana Torrinhas BD Dan L. Waitzberg MD PhD 《JPEN. Journal of parenteral and enteral nutrition》2015,39(8):941-947
Background: The daily consumption of dietary fiber is frequently below suggested recommendations. Using a double‐blind, controlled, randomized study, we assessed the efficiency and tolerance of a fiber‐enriched orange juice to supplement fiber intake in women. Materials and Methods: After 1 week of noninterventional observation, 192 healthy adult women ingested 400 mL of orange juice for 21 days, which either was not (placebo group) or was enriched with fiber (fiber group). Orange juice ingestion was registered daily and controlled for each week during the study period. Macronutrient, fiber, and energy intake were determined using a 3‐day food record, validated food chemical composition databases, and the “Pro Diet” software. Gastrointestinal symptoms were self‐evaluated daily by scoring 4 grades of symptom intensity and using a visual analog scale to grade pain severity. Results: No changes were observed for macronutrient and energy ingestion. For the placebo group (n = 97), the total fiber intake record was under the daily recommended value. In contrast, the fiber group (n = 95) displayed higher comparative values of total and soluble fiber consumption (P ≤ .001), achieving the daily recommended values of fiber intake. Both groups reported an increased frequency of slight bloating and rumbles over time (P ≤ .05). The fiber group also experienced a higher frequency of slight flatulence over time (P = .002). Conclusion: Consumption of fiber‐enriched orange juice was efficient to achieve the daily fiber intake recommendation for women, was not accompanied by intense adverse events, and may represent a suitable method to supplement fiber intake in woman. 相似文献
47.
48.
49.
Emma Ruiz José Manuel ávila Teresa Valero Susana del Pozo Paula Rodriguez Javier Aranceta-Bartrina ángel Gil Marcela González-Gross Rosa M. Ortega Lluis Serra-Majem Gregorio Varela-Moreiras 《Nutrients》2015,7(6):4739-4762
Energy intake, and the foods and beverages contributing to that, are considered key to understanding the high obesity prevalence worldwide. The relative contributions of energy intake and expenditure to the obesity epidemic, however, remain poorly defined in Spain. The purpose of this study was to contribute to updating data of dietary energy intake and its main sources from food and beverages, according to gender and age. These data were derived from the ANIBES (“Anthropometry, Intake, and Energy Balance in Spain”) study, a cross-sectional study of a nationally representative sample of the Spanish population (from 9–75 years old). A three-day dietary record, collected by means of a tablet device, was used to obtain information about food and beverage consumption and leftovers. The final sample comprised 2009 individuals (1,013 men, 996 women). The observed mean dietary energy intake was 7.6 ± 2.11 MJ/day (8.2 ± 2.22 MJ/day for men and 6.9 ± 1.79 MJ/day for women). The highest intakes were observed among adolescents aged 13–17 years (8.4 MJ/day), followed by children 9–12 years (8.2 ± 1.80 MJ/day), adults aged 18–64 (7.6 ± 2.14 MJ/day) and older adults aged 65–75 years (6.8 ± 1.88 MJ/day). Cereals or grains (27.4%), meats and derivatives (15.2%), oils and fats (12.3%), and milk and dairy products (11.8%) contributed most to daily energy intake. Energy contributions from non-alcoholic beverages (3.9%), fish and shellfish (3.6%), sugars and sweets (3.3%) and alcoholic beverages (2.6%) were moderate to minor. Contributions to caloric profile were 16.8%E from proteins; 41.1%E from carbohydrates, including 1.4%E from fiber; 38.5%E from fats; and 1.9%E from alcohol intake. We can conclude that energy intake is decreasing in the Spanish population. A variety of food and beverage groups contribute to energy intake; however, it is necessary to reinforce efforts for better adherence to the traditional Mediterranean diet. 相似文献
50.
Garcia-Silva Rafael Hernandez-Doño Susana Román-Amparo Jeniffer Patricia Trujillo-Vizuet Ma Guadalupe Mena-Vela Blanca Aurora Rizo-Pinto Andrea Tirado José Manuel Pérez Cetina-Díaz José Hiram Bulos-Rodríguez Pedro Granados Julio Sepúlveda-Delgado Jesús 《Clinical rheumatology》2021,40(8):3095-3103
Clinical Rheumatology - Systemic lupus erythematosus (SLE) is the prototypic autoimmune disease that disrupts numerous immunity mechanisms with the potential to exert damage to any organ or tissue.... 相似文献