Impact of trans-Planckian excitations on black-hole radiation in dipolar condensates

We consider a quasi-one-dimensional dipolar condensate in an analogue black hole setup. It is shown that the existence of a roton minimum in the condensate dispersion relation leaves deep imprints onto the Hawking radiation spectrum. In particular, the emitted radiation can be either more intense or suppressed, depending on the depth of the roton minimum in the excitation spectrum. In addition, we find that spontaneous particle creation occurs even when the horizon is removed. Our results establish that dipolar condensates offer a richer and more versatile environment for the simulation of particle production from the quantum vacuum in the presence of horizon-interfaces than their contact-interaction counterparts.Comment: 6+4 pages, 2 figure

Modelos Análogos para Flutuações do Cone de Luz.

Neste trabalho nós estudamos um modelo análogo para flutuações do cone de luz baseado em sistemas de ótica quântica não linear. Motivados pelos trabalhos recentes nas Refs. [7, 8, 9], nós apresentamos uma generalização apropriada para estes resultados. O ingrediente chave nestes trabalhos é que um campo de fundo flutuante pode mudar a velocidade de fase de um campo de prova acoplado a este campo de fundo através das não-linearidades do meio. Eles consideraram materiais não-lineares tendo susceptibilidade elétrica de segunda ordem, e o campo elétrico de fundo preparado no estado de vácuo, bem como no estado de vácuo squeezed. Aqui nós generalizamos estes resultados e consideramos materiais que possuam susceptibilidade de segunda e terceira ordem. Isto é importante se é desejado realizar medidas usando materiais centrossimétricos como o silício, no qual a susceptibilidade de segunda ordem é nula. Nós também consideramos o campo de fundo preparado no estado de vácuo, e em um estado coerente squeezed. Para estudar as flutuações do vácuo, nós também propomos uma função teste fiel para realizar os cálculos, em contraste com a distribuição Lorentziana usada em [9]. Nós argumentamos que com uma função teste mais realista, as contribuições de vácuo para as flutuações do cone de luz são até 100 vezes maiores que as encontradas anteriormente

Number-conserving solution for dynamical quantum backreaction in a Bose-Einstein condensate

We provide a number-conserving approach to the backreaction problem of small quantum fluctuations onto a classical background for the exactly soluble dynamical evolution of a Bose-Einstein condensate, experimentally realizable in the ultracold gas laboratory. A force density exerted on the gas particles which is of quantum origin is uniquely identified as the deviation from the classical Eulerian force density. The backreaction equations are then explored for the specific example of a finite size uniform density condensate initially at rest. By assuming that the condensate starts from a non-interacting regime, and in its ground state, we fix a well-defined initial vacuum condition, which is driven out-of-equilibrium by instantaneously turning on the interactions. The assumption of this initial vacuum accounts for the ambiguity in choosing a vacuum state for interacting condensates, which is due to phase diffusion and the ensuing condensate collapse. As a major finding, we reveal that the time evolution of the condensate cloud leads to condensate density corrections that cannot in general be disentangled from the quantum depletion in measurements probing the power spectrum of the total density. Furthermore, while the condensate is initially at rest, quantum fluctuations give rise to a nontrivial condensate flux, from which we demonstrate that the quantum force density attenuates the classical Eulerian force. Finally, the knowledge of the particle density as a function of time for a condensate at rest determines, to order $N^0$, where $N$ is the total number of particles, the quantum force density, thus offering a viable route for obtaining experimentally accessible quantum backreaction effects.Comment: 15 pages, 6 figure

A UTILIZAÇÃO DO TRIS-TRIMETIL-SILIU-SILANO COMO CO-INICIADORES EM RESINAS COMPOSTAS

Hoje o co-iniciador mais utilizado juntamente com a canforoquinona é o EDMAB. O EDMAB possui algumas limitações incluindo: sensibilidade a inibição de oxigênio, instabilidade sobre ácidos condicionantes, além de ter um potencial citotóxico a polpa dentária

Libidibia ferrea antimicrobial and disinfectant activity

Microorganisms are becoming resistant to the commonly used chemical disinfectants. Thereby, these chemical products should now be replaced by natural ones. In this context, this research aimed to evaluate the disinfectant activity of the extract and decoction of Libidibia ferrea leaves in different surfaces. Thus, two forms of jucá leaf extraction (decoction and hydroalcoholic extraction) were tested through the diffusion disk technique from Kirby and Bauer, growth curve, acceptability test with the population, and surface test. Results showed sensibility to decoction of S. aureus and E. faecalis strains; however, for the extract, the strains that demonstrated sensibility were S. aureus, P. aeruginosa, Micrococcus spp. Corynebacterium spp., and S. Typhimurium in the diffusion disk test. A reduction of the bacterial charge throughout the growth curve was seen through the absorbance values after 24 hours to the strains of E. coli, E. feacalis, Micrococcus spp. and K. pneumoniae in the concentration of 100 mg/mL of the decoction and extract. Regarding the surfaces test, there was a reduction in the bacterial charge in all tested strains. Therefore, the L. ferrea may be used as an effective alternative disinfectant measure

Granulomatose pulmonar de corpo estranho em um usuário crônico de cocaína em pó

We describe the case of a 33-year-old man, a chronic user of powder cocaine, who presented with dyspnea, fever, night sweats, and significant weight loss. Chest HRCT revealed centrilobular nodules, giving an initial impression of miliary tuberculosis. Therefore, he was started on an empirical, four-drug antituberculosis treatment regimen. Four weeks later, despite the tuberculosis treatment, he continued to have the same symptoms. We then performed transbronchial lung biopsy. Histopathological analysis of the biopsy sample revealed birefringent foreign body granuloma. A corroborative history of cocaine snorting, the presence of centrilobular nodules, and the foreign body-related histopathological findings led to a diagnosis of pulmonary foreign body granulomatosis. This report underscores the fact that pulmonary foreign body granulomatosis should be included in the differential diagnosis of clinical profiles resembling tuberculosis.Descrevemos o caso de um homem de 33 anos de idade, usuário crônico de cocaína em pó, que apresentava dispneia, febre, sudorese noturna e perda de peso significativa. A TCAR de tórax revelou nódulos centrolobulares, dando uma impressão inicial de tuberculose miliar. Por isso, o paciente passou a receber tratamento empírico com quatro tuberculostáticos. Quatro semanas depois, apesar do tratamento antituberculose, o paciente continuou a apresentar os mesmos sintomas. Foi então realizada a biópsia pulmonar transbrônquica. A análise histopatológica da amostra obtida revelou granuloma de corpo estranho birrefringente. A história de uso de cocaína por inalação, a presença de nódulos centrolobulares e os achados histopatológicos de corpos estranhos confirmaram o diagnóstico de granulomatose pulmonar de corpo estranho. Este relato destaca o fato de que a granulomatose pulmonar de corpo estranho deve ser incluída no diagnóstico diferencial de perfis clínicos que se assemelham a tuberculose.Univ Fed Sao Paulo, Escola Paulista Med, Hosp Sao Paulo, Disciplina Cirurgia Torac,Dept Cirurgia, Sao Paulo, SP, BrazilFundacao ABC, Fac Med, Disciplina Cirurgia Torac, Santo Andre, SP, BrazilSurgP&D Consultoria, Pesquisa & Desenvolvimento Cirurgia, Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Escola Paulista Med, Sao Paulo, SP, BrazilDisciplina de Cirurgia Torácica, Departamento de Cirurgia, Hospital São Paulo, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo (SP) BrasilEscola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo (SP) BrasilWeb of Scienc

Simulation with debriefing with video in the teaching of the respiratory physical examination: satisfaction and self-confidence of nursing students

Objective: To evaluate the satisfaction and self-confidence in the learning of nursing students who were part of an experimental class on teaching the respiratory physical examination, based on simulation with video debriefing.Method: This is an analytical-descriptive and quantitative study, conducted with a sample of 33 undergraduate nursing students from the Federal University of Uberlândia who participated in the experiential class based on simulation and using a video in the debriefing. Datacollection was performed by applying the Student Satisfaction and Self-Confidence in Learning (SSSCL) scale to students after participation in the class. Results: There was a predominance of females in the sample with 78.8% and young students with a mean age of 20.91 years. Regarding the satisfaction and self-confidence scale, averages of 4.36 and 4.15, respectively; all items of the scale obtained an average above four, except for item six, with an average of 3.39, even so, a value above the moderate. Female students had lower satisfaction (Bi= -0.451; p< 0.05), when compared to male students. Self-confidence, on the other hand, did not depend on the profile of the students. Conclusion: It is concluded that the use of simulation with the use of video in the debriefing promotes satisfaction and self-confidence in learning among nursing students.Trabalho de Conclusão de Curso (Graduação)Objetivo: Avaliar a satisfação e a autoconfiança na aprendizagem dos estudantes de Enfermagem que fizeram parte de uma aula experimental sobre ensino do exame físico respiratório, baseada em simulação com debriefingcom vídeo. Método: Trata-se de um estudo analítico-descritivo e quantitativo, realizado com uma amostra de 33 estudantes de graduação em Enfermagem da Universidade Federal de Uberlândia que participaram da aula experiencial baseada em simulação e em utilização de um vídeo no debriefing. A coleta de dados foi feita por meio da aplicação da escala de satisfação e da autoconfiança (Student Satisfaction and Self-Confidence in Learning-SSSCL) nos estudantes após a participação na aula. Resultados: Houve predomínio do sexo feminino na amostra com 78,8% e de estudantes jovens com idade média de 20,91 anos. Em relação à escala de satisfação e de autoconfiança, mostraram-se médias de 4,36 e 4,15, respectivamente; todos os itens da escala obtiveram média acima de quatro, com exceção do item seis, com média 3,39, mesmo assim, um valor acima do moderado. Estudantes do sexo feminino tiveram menor satisfação (Bi= -0,451; p< 0,05), quando comparadas aos estudantes masculinos. Já a autoconfiança, não dependeu do perfil dos estudantes. Conclusão: Conclui-se que o uso de simulação com o uso de vídeo no debriefingpromove satisfação e autoconfiança na aprendizagem entre os estudantes de Enfermagem

Identification of Inhibitors to trypanosoma cruzi sirtuins based on compounds developed to human enzymes

Chagas disease is an illness caused by the protozoan parasite Trypanosoma cruzi, affecting more than 7 million people in the world. Benznidazole and nifurtimox are the only drugs available for treatment and in addition to causing several side effects, are only satisfactory in the acute phase of the disease. Sirtuins are NAD+-dependent deacetylases involved in several biological processes, which have become drug target candidates in various disease settings. T. cruzi presents two sirtuins, one cytosolic (TcSir2rp1) and the latter mitochondrial (TcSir2rp3). Here, we characterized the effects of human sirtuin inhibitors against T. cruzi sirtuins as an initial approach to develop specific parasite inhibitors. We found that, of 33 compounds tested, two inhibited TcSir2rp1 (15 and 17), while other five inhibited TcSir2rp3 (8, 12, 13, 30, and 32), indicating that specific inhibitors can be devised for each one of the enzymes. Furthermore, all inhibiting compounds prevented parasite proliferation in cultured mammalian cells. When combining the most effective inhibitors with benznidazole at least two compounds, 17 and 32, demonstrated synergistic effects. Altogether, these results support the importance of exploring T. cruzi sirtuins as drug targets and provide key elements to develop specific inhibitors for these enzymes as potential targets for Chagas disease treatment