1,194 research outputs found

    Optical Line Width Broadening Mechanisms at the 10 kHz Level in Eu3+:Y2O3 Nanoparticles

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    We identify the physical mechanisms responsible for the optical homogeneous broadening in Eu3+:Y2O3 nanoparticles to determine whether rare-earth crystals can be miniaturized to volumes less than λ3 whilst preserving their appeal for quantum technology hardware. By studying how the homogeneous line width depends on temperature, applied magnetic field, and measurement time scale the dominant broadening interactions for various temperature ranges above 3 K were characterized. Below 3 K the homogeneous line width is dominated by an interaction not observed in bulk crystal studies. These measurements demonstrate that broadening due to size-dependent phonon interactions is not a significant contributor to the homogeneous line width, which contrasts previous studies in rare-earth ion nanocrystals. Importantly, the results provide strong evidence that for the 400 nm diameter nanoparticles under study the minimum line width achieved (45±1 kHz at 1.3 K) is not fundamentally limited. In addition, we highlight that the expected broadening caused by electric field fluctuations arising from surface charges is comparable to the observed broadening. Under the assumption that such Stark broadening is a significant contribution to the homogeneous line width, several strategies for reducing this line width to below 10 kHz are discussed. Furthermore, it is demonstrated that the Eu3+ hyperfine state lifetime is sufficiently long to preserve spectral features for timescales up to 1 s. These results allow integrated rare-earth ion quantum optics to be pursued at a sub-micron scale and hence, open up directions for greater scaling of rare-earth quantum technology

    Ritmo de base no eletrencefalograma de pacientes aidéticos

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    We studied the EEG of 73 patients diagnosed with HIV infection, with or without secondary complications. Sixty-eight belonged to CDC (Center for Disease Control) group IV and 38 presented signs or symptoms of encephalic neurological impairment. Rhytms constituting base activity were alpha (65.75%), beta (13.70%), theta (12.33%), and delta (8.22%). The alpha rhythm presented two modes: slow (8 to 9 Hz) in 25/48 or 52.08% of the cases and not-slow (>9 to 13 Hz) in 23/48 or 47.92% of the cases. The alpha slow-mode has been observed in about 10 to 15% of the normal population, with the 8 Hz frequency being found in only 1% of the normal adult population, which suggests that in some manner HIV is implicated in the slowing-down of the EEG base rhythm in AIDS patients. The patients from CDC group IV with encephalic neurological involvement presented a base rhythm significantly lower than those with non-encephalic involvement or the absence of neurological impairment.Estudamos o EEG de 73 pacientes com diagnóstico de infecção pelo HIV, com ou sem complicações secundárias. Sessenta e oito deles pertenciam ao grupo IV do CDC (Center for Disease Control) e 38 apresentavam sinais ou sintomas de comprometimento encefálico. Os ritmos que constituiram a atividtade de base foram o alfa (65,75%), o beta (13,70%), teta (12,33%) e o delta (8,22%). O ritmo alfa apresentou duas modalidades: a lenta (8 a 9Hz) em 25/48 ou 52,08% dos casos e a não-lenta (>9 a 13Hz) em 23/48 ou 47,92% dos casos. A modalidade lenta do ritmo alfa é observada em cerca de 10 a 15% da população normal, sendo a frequência de 8Hz encontrada em apenas 1% da população adulta normal, o que sugere que o HIV de alguma maneira está implicado na lentificação do ritmo de base no EEG de pacientes aidéticos. Os pacientes do grupo IV do CDC com envolvimento neurológico encefálico apresentaram ritmo de base significantemente menor que aqueles com envolvimento neurológico não encefálico ou ausência de comprometimento neurológico.Escola Paulista de MedicinaEPM EEGEPMEPM EEGSciEL

    Desperdício alimentar e satisfação do consumidor com o serviço de alimentação da Escola de Hotelaria e Turismo de Coimbra, Portugal

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    Introdução: O desperdício alimentar é matéria de interesse para os serviços de alimentação escolares. Uma das causas apontadas para sua ocorrência é a falta de consciência, por parte dos consumidores, para este problema. Objetivo: Avaliar o desperdício de alimentos nas refeições servidas no refeitório, a perceção dos consumidores em relação ao mesmo e sua satisfação com o serviço de alimentação. Metodologia: Foram avaliadas dois almoços, em dias consecutivos. As sobras e os restos resultantes da refeição foram pesados por componentes da mesma. Consideram-se inaceitáveis valores de desperdício superiores a 10%. As variáveis restantes foram avaliadas através da aplicação de um questionário aos utentes. Resultados e Discussão: A maioria dos indivíduos referiu estar satisfeita com o serviço de alimentação. Observaram-se 22,7% de sobras e 12,7% de restos, em média, nas refeições avaliadas. O componente do prato com maior quantidade de restos foi o peixe (25,37%), muito superior à carne (14,15%). Um valor superior a 20% de sobras foi encontrado para todos os componentes da refeição, exceto para o componente proteico e para o pão. Os inquiridos identificaram o fornecedor de hidratos de carbono como o componente mais desperdiçado, e referiram que normalmente não desperdiçam alimentos ao almoço. Conclusões: Apesar da satisfação com o serviço de refeições, os resultados do desperdício alimentar são considerados inaceitáveis e refletem a necessidade de melhorar o planeamento das refeições e a adequação das ementas às preferências dos consumidores. A dissociação entre a perceção de desperdício de alimentos e da quantidade e tipo de alimentos efetivamente desperdiçado justifica a intervenção ao nível da sensibilização dos usuários de cafeteria, como possível estratégia para reduzir o desperdício.Introduction: Food waste is a matter of concern in school foodservices. One of the causes given for its occurrence is the lackof awareness of consumers for food waste problem. Objective:Assess food waste of meals served at the cafeteria, the perceptionof consumers in relation to their own food waste and theirsatisfaction with the food service. Methodology: There wereassessed lunch meals, in two consecutive days. The leftoversand plate waste resulting from school lunch were weighed bymeal components. It was considered that values above 10% ofleftovers and plate waste were unacceptable. Other variableswere assessed through a questionnaire applied to consumers.Results and Discussion: Most respondents were satisfied with foodservice. It was found 22.7% of leftovers and 12.7% of plate wasteas average on the meals evaluated. The main dish componentwith highest amount of plate waste was fish (25.37%), muchhigher than meat (14.15%). An amount above 20% leftovers wasfound for all components, except for protein source and bread.There was a dissociation between the perception of wasted foodand actual plate waste. Conclusions: In spite of satisfaction ofconsumers with food service, the results of food waste found areconsidered unacceptable and reflect the need to improve theplanning of meals and menus adequacy to consumer preferences,as well as to develop strategies to reduce meals rejection. Thedissociation between perception of food waste and the amountand type of food effectively wasted, justify the intervention atthe level of awareness of users of cafeteria, as a possible strategyto reduce waste.Key words: Food Waste. Food Services. Consumer Satisfactio

    Thermal stability of sputter-deposited 330 austenitic stainless-steel thin films with nanoscale growth twins

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    We have explored the thermal stability of nanoscale growth twins in sputter-deposited 330 stainless-steel (SS) films by vacuum annealing up to 500 °C. In spite of an average twin spacing of only 4 nm in the as-deposited films, no detectable variation in the twin spacing or orientation of twin interfaces was observed after annealing. An increase in the average columnar grain size was observed after annealing. The hardness of 330 SS films increases after annealing, from 7 GPa for as-deposited films to around 8 GPa for annealed films, while the electrical resistivity decreases slightly after annealing. The changes in mechanical and electrical properties after annealing are interpreted in terms of the corresponding changes in the residual stress and microstructure of the films

    Dengue: achados de biópsia muscular em 15 pacientes

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    Dengue is known to produce a syndrome involving muscles, tendons and joints. The hallmark of this syndrome is severe myalgia but includes fever, cutaneous rash, and headache. The neuromuscular aspects of this infection are outlined only in isolated reports, and the muscle histopathological features during myalgia have not been described. In order to ascertain the actual neuromuscular involvement in dengue and better comprehend the histological nature of myalgia, we performed a clinical and neurological evaluation, a serum CPK level and a muscle biopsy (with histochemistry) in 15 patients (4 males), median age 23 years (range 14-47) with classic dengue fever, serologically confirmed, during the bra-zilian dengue epidemics from September 1986 to March 1987. All patients had a history of fever, headache and severe myalgia. Upon examination 4 had a cutaneous rash, 3 had fever, and 3 a small hepatomegaly. The neurological examination was unremarkable in all and included a manual muscle test. CPK was mildly elevated in only 3 patients. Muscle biopsy revealed a light to moderate perivascular mononuclear infiltrate in 12 patients and lipid accumulation in 11. Mild mitochondrial proliferation was seen in 3, few central nuclei in 3, rare foci of myonecrosis in 3, and 2 patients had type grouping. Dengue in our patients, produced myalgia but no detectable muscle weakness or other neuromuscular involvement. The main histopathological correlation with myalgia seems to be a perivascular mononuclear infiltrate and lipid accumulation.A síndrome clínica produzida pelo vírus da dengue, inclui febre, exantema, cefaléia e especialmente mialgia. Entretanto, as possiveis alterações morfológicas do músculo esquelético, eventualmente relacionadas com a mialgia, ainda não haviam sido estudadas em seres humanos com dengue. Nosso objetivo foi estudar o substrato, anatomopatológico da mialgia nesses pacientes. Foram avaliados 15 pacientes com diagnóstico de dengue, forma clássica, com idades variando de 14 a 47 anos (mediana de 23 anos), sendo 4 do sexo masculino e 11 do sexo feminino, através de exame clínico e neurológico, exames laboratoriais e biópsia muscular com histoquímica, durante a epidemia de dengue em Alagoas, em 1987. Todos os pacientes apresentavam história de cefaléia, febre e mialgia intensa, sem fraqueza muscular. Ao exame clínico observou-se exantema em 4 pacientes, febre em 3 e discreta hepatomegalia em 3. O exame neurológico foi normal em todos e a enzima CK sérica estava pouco elevada em 3 pacientes. A biópsia muscular revelou discreto infiltrado inflamatório mononuclear perivascular em 12 pacientes, acúmulo lipídico em 11, predominância de fibras do tipo I em 6, raros focos de necrose em 3, proliferação mitocondrial em 3, centralização nuclear em 3 e type grouping em 2. As alterações mais frequentemente observadas na biópsia muscular, infiltrado inflamatório perivascular e acúmulo lipídico, podem estar relacionadas com a mialgia.Escola Paulista de Medicina Department of NeurologyEscola Paulista de Medicina Department of PathologyUNIFESP, EPM, Department of NeurologyEscola Paulista de Medicina Department of PathologySciEL

    Levisticum officinale hairy root cultures: influence of light and light type on growth and essential oil production

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    The essential oils of Levisticum officinale W.D.J. Koch (Apiaceae), including those isolated from the roots, are used in the cosmetic, pharmaceutical and food industries [1]. This perennial and herbaceous plant, commonly known as lovage, is widely known by its aromatic, ornamental and medicinal properties. The effect of light and light type on growth and essential oil production of lovage hairy root cultures was studied by comparison of cultures maintained under “blue-basic” (400-550nm) and “day-light” 16h light photoperiod with control cultures maintained under darkness. All cultures were maintained in SH medium [2] and kept at 24ºC on orbital shakers at 80 r.p.m. Growth was evaluated by fresh weight (f.w.), dry weight (d.w.) and by the dissimilation method. The essential oil samples were isolated by distillation-extraction and analysed by GC and GC-MS. Control hairy root cultures showed a fifteen-fold d.w. biomass increase at the end of the growth period (six weeks), whereas an approximately eight-fold and ten-fold increase was obtained with “blue-basic” and “day-light” grown cultures, respectively. These differences were supported by morphological and histochemical analyses. Major changes were detected in the essential oil composition, but Z-falcarinol was in all cases the major oil constituent: in darkness, “day-light” and “blue-basic” grown cultures (75%, 94% and 61%, respectively).FC

    Anadenanthera colubrina vell brenan : anti-candida and antibiofilm activities, toxicity and therapeutical action

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    We evaluated the antifungal and antibiofilm potential of the hydroalcoholic extract of bark from Anadenanthera colubrina (vell.) Brenan, known as Angico, against Candida spp. Antifungal activity was evaluated using the microdilution technique through the Minimum Inhibitory and Fungicide Concentrations (MIC and MFC). The antibiofilm potential was tested in mature biofilms formed by Candida species and analyzed through the counting of CFU/mL and scanning electron micrograph (SEM). In vivo toxicity and therapeutic action was evaluated in the Galleria mellonella model. The treatment with the extract, in low doses, was able to reduce the growth of planktonic cells of Candida species. MIC values range between 19.5 and 39 µg/mL and MFC values range between 79 and 625 µg/mL. In addition was able to reduce the number of CFU/mL in biofilms and to cause structural alteration and cellular destruction, observed via SEM. A. colubrina showed low toxicity in the in vivo assay, having not affected the viability of the larvae at doses below 100mg/kg and high potential in the treatment of C. albicans infection. Considering its high antifungal potential, its low toxicity and potential to treatment of infections in in vivo model, A. colubrina extract is a strong candidate for development of a new agent for the treatment of oral candidiasis33CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ552562/2011-
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