The sudden change phenomenon of quantum discord

Even if the parameters determining a system's state are varied smoothly, the behavior of quantum correlations alike to quantum discord, and of its classical counterparts, can be very peculiar, with the appearance of non-analyticities in its rate of change. Here we review this sudden change phenomenon (SCP) discussing some important points related to it: Its uncovering, interpretations, and experimental verifications, its use in the context of the emergence of the pointer basis in a quantum measurement process, its appearance and universality under Markovian and non-Markovian dynamics, its theoretical and experimental investigation in some other physical scenarios, and the related phenomenon of double sudden change of trace distance discord. Several open questions are identified, and we envisage that in answering them we will gain significant further insight about the relation between the SCP and the symmetry-geometric aspects of the quantum state space.Comment: Lectures on General Quantum Correlations and their Applications, F. F. Fanchini, D. O. Soares Pinto, and G. Adesso (Eds.), Springer (2017), pp 309-33

SILPHENYLENE AND SILPHENYLENE-SILOXANE OLIGOMERS - STRUCTURE-PROPERTY RELATIONSHIPS

Some representative oligomers were prepared by polycondensation reactions of dimethyldichlorosilane with 1,4-di-Grignard reagent prepared from 1,4-dibromobenzene in diethyl ether. The structural characterization of the oligomers was carried out by FTIR and H-1, C-13, and Si-29 NMR spectroscopy. The ($) over bar M(n) values were determined by vapor pressure osmometry. The T-g values were measured by DSC and the thermodegradation process was analyzed by TGA. In all cases the oligomers prepared in the absence of the blocking end group showed siloxane units in the main chain, which were quantified by H-1 and Si-29 NMR. Si-29 NMR was also used to determine the oligomer sequence. It was possible to correlate the ($) over bar M(n) and structure with T-g and with temperature at 3% weight loss. The results agree with these obtained for structurally similar polymers.51758

Blends of high-density polyethylene with solid silicone additive

Silicone masterbatch (SMB) is a pelletized formulation containing 50% of an ultrahigh molecular-weight polydimethylsiloxane dispersed in polyethylene. This SMB is designed to be used as an additive in polyethylene-compatible systems to impart benefits such as processing improvement and modification of surface characteristics. In this work, binary blends of high-density polyethylene (HDPE) and SMB were prepared by melt-mixing technique to study the influence of this masterbatch on the processing and mechanical properties of HDPE. Ternary blends were also prepared by the addition of silane-grafted polyethylene (HDPE-VTES) as compatibilizer. The blends were analyzed by melting flow rate (MFR), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and tensile tests. Data of final torque and MFR showed that SMB improved the processability of pure HDPE. DSC results showed differences in crystalline behavior between binary and ternary blends. In the former, the degree of crystallinity increased up to 10 wt % of SMB content; beyond this concentration, it decreased. In ternary blends, a reverse behavior was observed. The morphologic study showed silicone particles uniformly distributed in HDPE matrix. With high SMB concentration, the addition of HDPE-VTES significantly reduced the size of silicone particles. In the range of SMB composition studied, the mechanical properties of blends lower slightly compared to pure HDPE. (C) 2002 John Wiley Sons, Inc.83112347235

Blends of organosilicon polymers with polystyrene and poly(2,6-dimethyl-1,4-phenylene oxide)

Blends of organosilicon polymers with polystyrene, PS, and poly(2,6-dimethyl-1,4-phenylene oxide), PPE, were investigated by transmission electron microscopy and differencial scanning calorimetry. Blends with poly(tetramethylsilphenylene-siloxane), PTMPS, showed a morphology characterized by globular domains dispersed in the organic matrix. An apparent homogeneous system was observed when poly(dimethylsilphenylene), PDSP, was mixed with PPE. A crystalline phase was found in samples with a higher PDSP content. The morphology of PS/PDSP blends with low PDSP content showed a dendritic phase dispersed in the PS-rich matrix. (C) 1997 John Wiley & Sons, Inc.35162609261

High-density polyethylene modified by polydimethylsiloxane

High-density polyethylene (HDPE) was modified by the grafting of polydimethylsiloxane (PDMS) through a free-radical process, in a melt-mixer chamber, using dicumyl peroxide (DCP) as an initiator. The influence of PDMS (0.2-0.8 mol %) and peroxide (0.03-0.08 mol %) concentrations on the grafting, final torque, and melt flow rate (MFR) of copolymers were investigated using factorial planning. Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), gel permeation chromatography (GPC), MFR, and rheometry were used to characterize the copolymers obtained. Surface plots showed that higher degrees of grafted PDMS and higher final torques were obtained with increase in the PDMS amount at low DCP levels and with increase in the DCP amount at low PDMS levels. The peaks of fusion and crystallization of the copolymers showed no significant changes with respect to HDPE. Data of MFR and GPC suggested that crosslinking reactions and/or chain extension occurred concomitant with the grafting reactions. Copolymers with high grafting degrees showed high MFR and low dynamic shear viscosities in comparison with low grafting degree copolymers, which is probably due to the migration of the PDMS-containing copolymers on the surface. (C) 2001 John Wiley & Sons, Inc.82143460346

Factors associated to the length of time on mechanical ventilation in the postoperative period of cardiac surgery

Nosso objetivo foi identificar fatores associados ao tempo de ventilação mecânica (VM) no pós-operatório de cirurgia cardíaca e verificar associação entre tempo de entubação endotraqueal, tempo de internação na Unidade de Terapia Intensiva (UTI) e hospitalar. Estudo longitudinal, retrospectivo com 116 prontuários de adultos submetidos à cirurgia cardíaca no período de março 2012 a maio 2013. A média de idade foi 57±14 anos; houve predomínio do sexo masculino e de cirurgia de revascularização do miocárdio (52,6%). O tempo VM foi 15,25 (7,66-23,68) horas. Foram relacionadas com maior tempo em VM a idade (r=0,5; p<0,001), comorbidades (r=0,344; p<0,001), tempo de circulação extracorpórea (r=0,244; p=0,008), tempo de sedação contínua (r=0,607; p<0,001), doses sedativas (r=0,4; p<0,001), tempo de vasoconstritores e vasodilatadores (r=0,711; p<0,001; r=0,368; p<0,001), drenagem da 1ª hora (r=0,201; p<0,031), permanência dos drenos (r=0,445; p<0,001), complicações do pós-operatório (r=0,524; p<0,001) e permanência hospitalar. Nossos dados confi rmam que tanto variáveis pré, trans e pós-operatórias prolongam o tempo de VM e, consequentemente, a permanência hospitalar.Nuestro objetivo fue identificar los factores asociados con la duración de la ventilación mecánica (VM) en postoperatorio de cirugía cardiaca y evaluar la asociación entre la duración de la intubación endotraqueal, la duración de la estancia en la Unidad de Cuidados Intensivos (UCI) y el hospital. Estudio longitudinal, retrospectivo con una muestra de 116 adultos sometidos a cirugía cardíaca de marzo 2012 a mayo 2013. La edad media fue de 57±14 años, predominio masculino y la realización de revascularización coronaria (52,6%). El tempo de VM fue 15,25 (7,66 a 23,68) horas. Se asociaron con una mayor edad MV (r=0,5,p<0,001), la comorbilidad (r=0,344,p<0,001), el tiempo de circulación extracorpórea (r=0,244, p=0,008), la duración de la sedación continua (r=0,607, p<0,001), las dosis sedantes (r=0,4,p<0,001), el tiempo de vasoconstrictores y vasodilatadores (r=0,711, p<0,001,r=0,368,p<0,001), el drenaje del primer tiempo (r=0,201,p<0,031), la presencia de drenajes (r=0,445,p<0,001), las complicaciones postoperatorias (r=0,524,p<0,001) y la estancia hospitalaria. Nuestros datos confirman que tanto variables pre y postoperatorias prolongan el tiempo de VM y, por lo tanto, la estancia en el hospital.Our objective was to identify factors associated with the duration of mechanical ventilation (MV) postoperative to cardiac surgery and assess the association between duration of endotracheal intubation, length of stay in the Intensive Care Unit (ICU) and hospital. Longitudinal, retrospective study of medical records of 116 adults undergoing cardiac surgery from March 2012 to May 2013. The mean age was 57±14 years, predominantly male and coronary artery bypass grafting surgery (52.6%). The MV time was 15.25(7.66 to 23.68) hours. Associated with longer MV was the age (r=0.5,p<0.001), comorbidities (r=0.344,p<0.001), cardiopulmonary bypass time (r=0.244,p=0.008), duration of continuous sedation (r=0.607,p<0.001), sedative doses (r=0.4, p<0.001), time of vasoconstrictors and vasodilators (r=0.711, p< 0.001, r=0.368, p<0.001), drainage of the 1st time (r=0.201, p<0.031), presence of drains (r=0.445, p<0.001), postoperative complications (r=0.524, p< 0.001) and hospital stay. Our data confi rms that both preoperative, transoperative and postoperative variables prolong the VM and therefore the hospital stay

Stressors in attempted suicide by poisoning: a sex comparison Estressores na tentativa de suicídio por envenenamento: uma comparação entre os sexos

OBJECTIVE: To identify stressors in attempted suicide by poisoning and to analyze differences between men and women. METHOD: This quantitative, comparative, cross-sectional study evaluated 110 patients aged between 14 and 78 years. The following instruments used were: standardized Mini International Neuropsychiatric Interview (MINI) version 5.0.0 and an interview form specifically designed for the study. RESULTS: 70% of the suicide attempters were female; mean age was 28.1 years; 98.2% presented at least one psychiatric disorder. Among the stressors assessed, significant differences were observed between men and women for: not having a spouse, 72.7% among men and 54.5% among women; attempted suicide planning, 66.7% among men and 46.8% among women; being under the influence of alcohol during the attempted suicide, 51.5% among men and 26.0% among women; harmful use of alcohol, 42.4% in men and 22.1% in women; sexual abuse, 22.1% in women and 6.1% in men. CONCLUSIONS: Women presented a three times higher number of attempted suicides by poisoning. The identification of stressors with significant differences between sexes in the high-risk population here described can help define and organize strategies aimed at suicide prevention. Similar studies should be conducted in the general population.<br>OBJETIVOS: Identificar estressores na tentativa de suicídio por envenenamento e analisar diferenças entre homens e mulheres. MÉTODO: Estudo quantitativo, transversal e comparativo que avaliou 110 pacientes, com idades entre 14 e 78 anos. Os instrumentos de avaliação utilizados foram: entrevista padronizada Mini International Neuropsychiatric Interview (MINI), versão 5.0.0, e formulário de entrevista desenvolvido especificamente para o estudo. RESULTADOS: 70% dos pacientes eram mulheres; a idade média foi de 28,1 anos; 98,2% apresentavam pelo menos um transtorno psiquiátrico. Dentre os estressores avaliados, foram observadas diferenças significativas entre os sexos para: ausência de convívio conjugal, 72,7% entre homens e 54,5% entre mulheres; planejamento da tentativa de suicídio por envenenamento, 66,7% nos homens e 46,8% nas mulheres; estar sob o efeito de álcool durante a tentativa de suicídio por envenenamento, 51,5% entre os homens e 26,0% entre as mulheres; uso nocivo de bebidas alcoólicas, 42,4% dos homens e 22,1% das mulheres; abuso sexual, 22,1% das mulheres e 6,1% dos homens. CONCLUSÕES: As mulheres apresentaram três vezes mais tentativas de suicídio por envenenamento do que os homens. A identificação de estressores com diferença significativa entre os sexos na população de risco aqui estudada oferece subsídios para a definição e prospecção de estratégias específicas para a prevenção do suicídio. Outros estudos similares na população geral devem ser realizados

Suicidal behavior in the community: prevalence and factors associated with suicidal ideation Comportamento suicida na comunidade: prevalência e fatores associados à ideação suicida

OBJECTIVES: To estimate the life prevalence rates of suicidal ideation, suicidal plans and suicide attempts and verify factors associated to suicidal ideation. METHODS: 515 individuals > 14 years old were selected at random (cluster and stratified sample) and assessed by means of the WHO SUPRE-MISS interview, SRQ-20 and AUDIT. Life prevalence rates were estimated. Uni and multivariate analyses were performed. Odds ratios, together with confidence intervals, were adjusted by gender and age. RESULTS: Life prevalence rates were 17.1% (95% CI: 12.9 - 21.2) for suicidal ideation, 4.8% (95% CI: 2.8 - 6.8) for plans and 2.8% (95% CI: 0.09 - 4.6) for suicide attempts. Only one-third of those who attempted suicide were later treated at a health facility. The 12-month prevalence rates were, respectively, 5.3% (95% CI: 3.5 - 7.2), 1.9% (95% CI: 1.0 - 2.8) and 0.4% (95% CI: -0.3 - 1.1). Suicidal ideation was more frequently reported by women (OR = 1.7), young adults (20-29 years old: OR = 2.9; 30-39 years old: OR = 3.6, compared to the 14-19 year old group), those living alone (OR = 4.2) and those presenting mental disorders (OR between 2.8 and 3.8). CONCLUSION: The prevalence of suicidal behavior was similar to that found in most studies carried out in other countries. Suicidal ideation was consistently associated with factors related to mental disorders or psychological distress. This should be taken into account when developing strategies to prevent suicidal behavior.<br>OBJETIVOS: Estimar a prevalência de ideação suicida (IS), planos e tentativas de suicídio (TS) ao longo da vida e identificar variáveis associadas à ideação suicida. MÉTODOS: Foi realizado inquérito domiciliar com 515 indivíduos > 14 anos de idade, selecionados aleatoriamente, mediante amostragem estratificada, por conglomerados. Foram avaliados utilizando-se uma entrevista padronizada, da Organização Mundial de Saúde (OMS), sobre comportamento suicida (SUPRE-MISS), SRQ-20 e AUDIT. Foram calculadas as prevalências na vida e ajustados modelos de regressão logística uni e multivariada, calculando razões de chances (RC), controlando-se sexo e idade como covariáveis, com seus respectivos intervalos de confiança (IC). RESULTADOS: As prevalências foram de 17,1% (IC 95%: 12,9 - 21,2) para ideação suicida, 4,8% (IC 95%: 2,8 - 6,8) para planos e 2,8% (IC 95%: 0,09 - 4,6) para tentativas de suicídio. De cada três tentativas de suicídio, apenas uma chegou a ser atendida em um serviço médico. Ao longo dos últimos 12 meses, as prevalências foram, respectivamente, de 5,3% (IC 95%: 3,5 - 7,2), 1,9% (IC 95%: 1,0 - 2,8) e 0,4% (IC 95%: -0,3 - 1,1). A ideação suicida, ao longo da vida, foi mais freqüente entre mulheres (RC = 1,7), adultos jovens (RC 20-29 anos = 2,9; RC 30-39 anos = 3,6, quando comparados com a faixa etária de 14-19 anos), entre os que vivem sozinhos (RC = 4,2) e nos indivíduos que apresentaram indicadores de transtorno mental (RC entre 2,8 e 3,8). CONCLUSÕES: As prevalências não diferiram do observado pela maioria dos estudos realizados em outros países. A ideação suicida esteve consistentemente associada a indicadores de transtornos mentais ou de sofrimento psíquico. Essa observação, juntaente com o conhecimento dos fatores socioambientais associados ao comportamento suicida, deve ser levada em consideração na elaboração de estratégias de prevenção