107 research outputs found

    Fano resonances in plasmonic core-shell particles and the Purcell effect

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    Despite a long history, light scattering by particles with size comparable with the light wavelength still unveils surprising optical phenomena, and many of them are related to the Fano effect. Originally described in the context of atomic physics, the Fano resonance in light scattering arises from the interference between a narrow subradiant mode and a spectrally broad radiation line. Here, we present an overview of Fano resonances in coated spherical scatterers within the framework of the Lorenz-Mie theory. We briefly introduce the concept of conventional and unconventional Fano resonances in light scattering. These resonances are associated with the interference between electromagnetic modes excited in the particle with different or the same multipole moment, respectively. In addition, we investigate the modification of the spontaneous-emission rate of an optical emitter at the presence of a plasmonic nanoshell. This modification of decay rate due to electromagnetic environment is referred to as the Purcell effect. We analytically show that the Purcell factor related to a dipole emitter oriented orthogonal or tangential to the spherical surface can exhibit Fano or Lorentzian line shapes in the near field, respectively.Comment: 28 pages, 10 figures; invited book chapter to appear in "Fano Resonances in Optics and Microwaves: Physics and Application", Springer Series in Optical Sciences (2018), edited by E. O. Kamenetskii, A. Sadreev, and A. Miroshnichenk

    Omega-3 supplementation in patients with sepsis: a systematic review and meta-analysis of randomized trials.

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    BACKGROUND: Nutritional supplementation of omega-3 fatty acids has been proposed to modulate the balance of pro- and anti-inflammatory mediators in sepsis. If proved to improve clinical outcomes in critically ill patients with sepsis, this intervention would be easy to implement. However, the cumulative evidence from several randomized clinical trials (RCTs) remains unclear. METHODS: We searched the Cochrane Library, MEDLINE, and EMBASE through December 2016 for RCTs on parenteral or enteral omega-3 supplementation in adult critically ill patients diagnosed with sepsis or septic shock. We analysed the included studies for mortality, intensive care unit (ICU) length of stay, and duration of mechanical ventilation, and used the Grading of Recommendations Assessment, Development and Evaluation approach to assess the quality of the evidence for each outcome. RESULTS: A total of 17 RCTs enrolling 1239 patients met our inclusion criteria. Omega-3 supplementation compared to no supplementation or placebo had no significant effect on mortality [relative risk (RR) 0.85; 95% confidence interval (CI) 0.71, 1.03; P = 0.10; I (2) = 0%; moderate quality], but significantly reduced ICU length of stay [mean difference (MD) -3.79 days; 95% CI -5.49, -2.09; P < 0.0001, I (2) = 82%; very low quality] and duration of mechanical ventilation (MD -2.27 days; 95% CI -4.27, -0.27; P = 0.03, I (2) = 60%; very low quality). However, sensitivity analyses challenged the robustness of these results. CONCLUSION: Omega-3 nutritional supplementation may reduce ICU length of stay and duration of mechanical ventilation without significantly affecting mortality, but the very low quality of overall evidence is insufficient to justify the routine use of omega-3 fatty acids in the management of sepsis

    Long-term microdystrophin gene therapy is effective in a canine model of Duchenne muscular dystrophy

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    Duchenne muscular dystrophy (DMD) is an incurable X-linked muscle-wasting disease caused by mutations in the dystrophin gene. Gene therapy using highly functional microdystrophin genes and recombinant adeno-associated virus (rAAV) vectors is an attractive strategy to treat DMD. Here we show that locoregional and systemic delivery of a rAAV2/8 vector expressing a canine microdystrophin (cMD1) is effective in restoring dystrophin expression and stabilizing clinical symptoms in studies performed on a total of 12 treated golden retriever muscular dystrophy (GRMD) dogs. Locoregional delivery induces high levels of microdystrophin expression in limb musculature and significant amelioration of histological and functional parameters. Systemic intravenous administration without immunosuppression results in significant and sustained levels of microdystrophin in skeletal muscles and reduces dystrophic symptoms for over 2 years. No toxicity or adverse immune consequences of vector administration are observed. These studies indicate safety and efficacy of systemic rAAV-cMD1 delivery in a large animal model of DMD, and pave the way towards clinical trials of rAAV-microdystrophin gene therapy in DMD patients

    Relationship among Apis mellifera L. stings, swarming and climate conditions in the city of Rio Claro, SP, Brazil

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    The presence of bees (Apis mellifera L.) in urban areas has increased in recent years due to environmental disturbances caused by humans. Bee migration to cities may provoke serious accidents, since some people present allergic reactions to their venoms. In Rio Claro city, São Paulo state, Brazil, the number of calls to the fire brigade for removal of bee swarms, and the number admissions in local hospitals due to bee stings were investigated during 2002 and 2003, and a correlation between these data and the average temperature, rainfall and relative humidity was found. The study period was divided into three phases according to the number of times that the fire brigade was called to remove swarms (263 times): January to July 2002 - 51 calls (19.39%); August 2002 to July 2003 - 140 calls (53.23%); and August to December 2003 - 72 calls (27.38%). A significant correlation among the number of calls, the local temperature and rainfall was detected. The number of accidents was not associated with environmental variables. Based on the current results, public activities for prevention of bee attacks may be developed to avoid unwanted contact between humans and these insects, and/or provide the appropriate management of the colonies

    Ethnopedology of a Quilombola Community in Minas Gerais: Soils, Landscape, and Land Evaluation

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    Quilombolas are Afro-brazilian rural peasants who descended from escaped slaves who tried to carve out territories of autonomy (called Quilombos) by collective organization and resistance. Despite many anthropological and ethnopedological studies, little research has been carried out to identify the agricultural practices and the knowledge of people who live in the Quilombos (Quilombolas). Peasant communities who live from land resources have wide empirical knowledge related to local soils and landscapes. In this respect, ethnopedology focuses on their relationship with local practices, needs, and values. We carried out an ethnopedological evaluation of the soils, landscape and land suitability of the Malhada Grande Quilombola Territory, aiming to examine the local criteria involved in land-use decision making, and evaluate the legitimacy of local knowledge. For this purpose, participatory workshops allowed environmental stratification of the Quilombolas into landscape units, recognition of soil types, and evaluation of land-use criteria. This approach was combined with conventional soil sampling, description, and analysis. The Brazilian System of Soil Classification and its approximations to the WRB/FAO system and the SAAT land evaluation system were compared with the local classificatory systems, showing several convergences. The Quilombolas stratified the local environment into eight landscape units (based on soil, topography, and vegetation) and identified eight soil types with distinct morphological, chemical, and physical attributes. The conventional soil survey identified thirteen soil classes, in the same eight landscape units, organized as soil associations. The apparent contradictions between local knowledge and Pedology were relative since the classification systems were established based on different criteria, goals, and sampling references. Most soils are only suitable for pasture, with restricted agricultural use, due to water or oxygen deficiencies. The current land use was only inconsistent with the technical recommendations when socioecological constraints such as the semiarid climate, land availability, and economic conditions for land management led to overuse of the land. Local knowledge demonstrated its legitimacy and allowed a useful and fruitful exchange of information with the academic view of soil-landscape interplays. Although mostly unknown by the scientific community, local knowledge proved capable of achieving social welfare and food security. In addition, a participatory survey proved to be a core factor for more grounded and detailed data collection on how Quilombolas decide land use on a local scale

    Análise da implantação do Programa Telessaúde Brasil em Pernambuco, Brasil: estudo de casos

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    Resumo A Rede de Núcleos de Telessaúde (RedeNutes) integra o Programa Telessaúde Brasil e desenvolve ações para Estratégia Saúde da Família, por meio dos serviços de teleassistência e tele- educação. O objetivo foi avaliar o grau de implantação da RedeNutes em seis municípios de Pernambuco. Tratou-se de pesquisa avaliativa, tipo análise da implantação no segundo componente, referente à análise da influência do grau de implantação sobre os efeitos observados, apoiada na estratégia estudo de casos múltiplos. A análise envolveu as dimensões gestora, municipal, global e seus componentes: planejamento, desenvolvimento, portal, teleassistência e tele-educação. Na dimensão Gestora, o grau de implantação foi considerado implantado; nas dimensões Municipal e Global, parcialmente implantado; entretanto o componente Teleassistência encontra-se não implantado. Concluiu-se que a Telessaúde pode contribuir com a melhoria do cuidado integral à saúde da população assistida, porém necessita de superar os problemas de adesão à intervenção, sobretudo em relação à Teleassistência
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