136 research outputs found

    Resistance of endodontically treated roots restored with different fibre post systems with or without post space preparation: in vitro analysis and SEM investigation.

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    Aim: To compare the mechanical resistance to fracture of two conical post systems placed with no preparation of the root canal with that of double taper fibre posts seated in endodontically treated single roots after standard post space preparation using dedicated drills. Methodology: Thirty fibre posts with double (G1, n = 10, DT Light Post) and single taper (G2, n = 10, SurgiPost Multiconical; G3, n = 10, Tech ES Endoshape) were luted with self-adhesive cement in endodontically treated single roots using different post space preparation techniques. The bonded posts were experimentally loaded until failure and the maximum load to fracture was registered. Fracture patterns were qualitatively evaluated and SEM analysis was performed to assess the quality of endodontic treatments and cementation. Data were statistically analysed by means of one-way ANOVA. Results: The mean maximum load to fracture was 165.05 23.46 N in G1, 151.52 16.23 N in G2 and 129.09 15.25 N in G3. Statistically significant differences were pointed out between G1 and G3 (p < 0.01) and G2 and G3 (p < 0.05). No root fractures were evidenced. SEM analyses showed slightly thicker cement ayers at the apical and middle thirds of single taper posts (G2 and G3). Conclusions: DT Light Post and SurgiPost Multiconical fibre posts showed similar properties in terms of mechanical resistance to fracture and higher than those of Tech ES Endoshape. Unrestorable root fractures did not occur with any of the tested posts

    Unidirectional reflection from an integrated 'taiji' microresonator

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    We study light transmission and reflection from an integrated microresonator device, formed by a circular microresonator coupled to a bus waveguide, with an embedded S-shaped additional crossover waveguide element that selectively couples counter-propagating modes in a propagation-direction-dependent way. The overall shape of the device resembles a 'taiji' symbol, hence its name. While Lorentz reciprocity is preserved in transmission, the peculiar geometry allows us to exploit the non-Hermitian nature of the system to obtain high-contrast unidirectional reflection with negligible reflection for light incident in one direction and a significant reflection in the opposite direction

    Optical properties of organic/inorganic perovskite microcrystals through the characterization of Fabry-Perot resonances

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    [EN] A precise knowledge of the optical properties, specifically the refractive index, of organic/inorganic perovskites, is essential for pushing forward the performance of the current photovoltaic devices that are being developed from these materials. Here we show a robust method for determining the real and the imaginary part of the refractive index of MAPbBr(3) thin films and micrometer size single crystals with planar geometry. The simultaneous fit of both the optical transmittance and the photoluminescence spectra to theoretical models defines unambiguously the refractive index and the crystal thickness. Because the method relies on the optical resonance phenomenon occurring in these microstructures, it can be used to further develop optical microcavities from perovskites or from other optical materials.This work was supported by the Spanish ministry of Economy, Industry and Competitiveness (MINECO) through the projects TEC2015-74405-JIN, MAT2015-69669-P as well as the regional projects of both Provincia Autonoma di Trento (PAT) of Italy, through the call Grandi Progetti 2012: SIQURO and the Comunidad Valenciana of Spain project PrometeoII/2014/026.Ramiro Manzano, F.; García-Aboal, R.; Fenollosa Esteve, R.; Biasi, S.; Rodriguez, I.; Atienzar Corvillo, PE.; Meseguer Rico, FJ. (2020). Optical properties of organic/inorganic perovskite microcrystals through the characterization of Fabry-Perot resonances. Dalton Transactions. 49(36):12798-12804. https://doi.org/10.1039/d0dt02254c1279812804493

    MICROPROPAGATION OF Gypsophila paniculata THROUGH CULTURE OF NODAL SEGMENTS

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    Gypsophila paniculata é uma das principais flores de corte comercializadas no mercado brasileiro. Comercialmente ela é propagada por métodos vegetativos in vitro, entretanto poucas informações científicas são disponíveis sobre este assunto. Este trabalho teve como objetivo estabelecer um protocolo de micropropagação desta espécie. As plantas matrizes de Gypsophila paniculata cv Golan foram obtidas de produtor comercial, plantadas em vasos de 20 L e mantidas em casa-de-vegetação, com temperatura e umidade controladas. Como explantes, foram utilizados segmentos nodais com um a dois centímetros de comprimento. Os explantes foram submetidos a tratamento com álcool 70% durante 30 segundos, seguido por hipoclorito de sódio 2% durante 10 min. Em seguida, foram cultivados em meio MS contendo duas concentrações de cinetina (CIN), com ou sem 3,0 mM de ácido naftalenoacético e com 0,3 mM de giberelina (GA3). O melhor resultado de multiplicação destes segmentos nodais foi obtido no meio MS com 0,5 mM de CIN e 0,3 mM de GA3.Gypsophila paniculata is one of the principal cut flowers on the Brazilian market. Commercially it is propagated by in vitro methods, however very few scientific information is available about it. The goal of this work was to establish in vitro technology to propagate Gypsophila paniculata through nodal segments. Gypsophila plants cultivar Golan obtained from a grower were used to start this research. They were planted in pots and maintained inside greenhouse under controlled temperature and relative humidity. Nodal segments one to two centimeters long were removed from these plants and immersed in alcohol 70% during 30 s, followed by sodium hypochlorite 2% during 10 min. They were then cultured in vitro on MS medium containing two concentrations of kinetin (KIN), with or without 3 mM naphtalenacetic acid and with 0.3 mM gibberellin (GA3). Better multiplication of the nodal segments was obtained in MS media containing 0.5 mM KIN and 0.3 mM GA3

    Early goal-directed therapy using a physiological holistic view: the ANDROMEDA-SHOCK—a randomized controlled trial

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    Septic shock is a highly lethal condition. Early recognition of tissue hypoperfusion and its reversion are key factors for limiting progression to multiple organ dysfunction and death. Lactate‐targeted resuscitation is the gold‐standard under current guidelines, although it has several pitfalls including that non‐hypoxic sources of lactate might predominate in an unknown proportion of patients. Peripheral perfusion‐targeted resuscitation might provide a real‐time response to increases in ow that could lead to a more timely decision to stop resuscitation, thus avoiding uid overload and the risks of over‐resuscitation. This article reports the rationale, study design and analysis plan of the ANDROMEDA‐SHOCK Study. Methods: ANDROMEDA‐SHOCK is a randomized controlled trial which aims to determine if a peripheral perfusion‐ targeted resuscitation is associated with lower 28‐day mortality compared to a lactate‐targeted resuscitation in patients with septic shock with less than 4 h of diagnosis. Both groups will be treated with the same sequential approach during the 8‐hour study period pursuing normalization of capillary re ll time versus normalization or a decrease of more than 20% of lactate every 2 h. The common protocol starts with uid responsiveness assessment and uid loading in responders, followed by a vasopressor and an inodilator test if necessary. The primary outcome is 28‐day mortality, and the secondary outcomes are: free days of mechanical ventilation, renal replacement therapy and vasopressor support during the rst 28 days after randomization; multiple organ dysfunction during the rst 72 h after randomization; intensive care unit and hospital lengths of stay; and all‐cause mortality at 90‐day. A sample size of 422 patients was calculated to detect a 15% absolute reduction in mortality in the peripheral perfusion group with 90% power and two‐tailed type I error of 5%. All analysis will follow the intention‐to‐treat principle. Conclusions: If peripheral perfusion‐targeted resuscitation improves 28‐day mortality, this could lead to simpli ed algorithms, assessing almost in real‐time the reperfusion process, and pursuing more physiologically sound objec‐ tives. At the end, it might prevent the risk of over‐resuscitation and lead to a better utilization of intensive care unit resources

    The practice of intensive care in Latin America: a survey of academic intensivists

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    Intensive care medicine is a relatively young discipline that has rapidly grown into a full-fledged medical subspecialty. Intensivists are responsible for managing an ever-increasing number of patients with complex, life-threatening diseases. Several factors may influence their performance, including age, training, experience, workload, and socioeconomic context. The aim of this study was to examine individual- and work-related aspects of the Latin American intensivist workforce, mainly with academic appointments, which might influence the quality of care provided. In consequence, we conducted a cross-sectional study of intensivists at public and private academic and nonacademic Latin American intensive care units (ICUs) through a web-based electronic survey submitted by email. Questions about personal aspects, work-related topics, and general clinical workflow were incorporated. RESULTS: Our study comprised 735 survey respondents (53% return rate) with the following country-specific breakdown: Brazil (29%); Argentina (19%); Chile (17%); Uruguay (12%); Ecuador (9%); Mexico (7%); Colombia (5%); and Bolivia, Peru, Guatemala, and Paraguay combined (2%). Latin American intensivists were predominantly male (68%) young adults (median age, 40 [IQR, 35-48] years) with a median clinical ICU experience of 10 (IQR, 5-20) years. The median weekly workload was 60 (IQR, 47-70) h. ICU formal training was between 2 and 4 years. Only 63% of academic ICUs performed multidisciplinary rounds. Most intensivists (85%) reported adequate conditions to manage patients with septic shock in their units. Unsatisfactory conditions were attributed to insufficient technology (11%), laboratory support (5%), imaging resources (5%), and drug shortages (5%). Seventy percent of intensivists participated in research, and 54% read scientific studies regularly, whereas 32% read no more than one scientific study per month. Research grants and pharmaceutical sponsorship are unusual funding sources in Latin America. Although Latin American intensivists are mostly unsatisfied with their income (81%), only a minority (27%) considered changing to another specialty before retirement. CONCLUSIONS: Latin American intensivists constitute a predominantly young adult workforce, mostly formally trained, have a high workload, and most are interested in research. They are under important limitations owing to resource constraints and overt dissatisfaction. Latin America may be representative of other world areas with similar challenges for intensivists. Specific initiatives aimed at addressing these situations need to be devised to improve the quality of critical care delivery in Latin America

    Search for 14.4 keV solar axions from M1 transition of Fe-57 with CUORE crystals

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    We report the results of a search for axions from the 14.4 keV M1 transition from Fe-57 in the core of the sun using the axio-electric effect in TeO2 bolometers. The detectors are 5x5x5 cm3 crystals operated at about 10 mK in a facility used to test bolometers for the CUORE experiment at the Laboratori Nazionali del Gran Sasso in Italy. An analysis of 43.65 kg d of data was made using a newly developed low energy trigger which was optimized to reduce the detectors energy threshold. An upper limit of 0.63 c kg-1 d-1 was established at 95% C.L.. From this value, a lower bound at 95% C.L. was placed on the Peccei-Quinn energy scale of fa >= 0.76 10**6 GeV for a value of S=0.55 for the flavor-singlet axial vector matrix element. Bounds are given for the interval 0.15 < S < 0.55.Comment: 14 pages, 6 figures, submitted to JCA

    Validation of techniques to mitigate copper surface contamination in CUORE

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    In this article we describe the background challenges for the CUORE experiment posed by surface contamination of inert detector materials such as copper, and present three techniques explored to mitigate these backgrounds. Using data from a dedicated test apparatus constructed to validate and compare these techniques we demonstrate that copper surface contamination levels better than 10E-07 - 10E-08 Bq/cm2 are achieved for 238U and 232Th. If these levels are reproduced in the final CUORE apparatus the projected 90% C.L. upper limit on the number of background counts in the region of interest is 0.02-0.03 counts/keV/kg/y depending on the adopted mitigation technique.Comment: 10 pages, 6 figures, 6 table

    The Brazilian Registry of Adult Patient Undergoing Cardiovascular Surgery, the BYPASS Project: Results of the First 1,722 Patients

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    Objective: To report the early results of the BYPASS project - the Brazilian registrY of adult Patient undergoing cArdiovaScular Surgery - a national, observational, prospective, and longitudinal follow-up registry, aiming to chart a profile of patients undergoing cardiovascular surgery in Brazil, assessing the data harvested from the initial 1,722 patients. Methods: Data collection involved institutions throughout the whole country, comprising 17 centers in 4 regions: Southeast (8), Northeast (5), South (3), and Center-West (1). The study population consists of patients over 18 years of age, and the types of operations recorded were: coronary artery bypass graft (CABG), mitral valve, aortic valve (either conventional or transcatheter), surgical correction of atrial fibrillation, cardiac transplantation, mechanical circulatory support and congenital heart diseases in adults. Results: 83.1% of patients came from the public health system (SUS), 9.6% from the supplemental (private insurance) healthcare systemsand 7.3% from private (out-of-pocket) clinic. Male patients comprised 66%, 30% were diabetics, 46% had dyslipidemia, 28% previously sustained a myocardial infarction, and 9.4% underwent prior cardiovascular surgery. Patients underwent coronary artery bypass surgery were 54.1% and 31.5% to valve surgery, either isolated or combined. The overall postoperative mortality up to the 7th postoperative day was 4%for CABG was 2.6%, and for valve operations, 4.4%. Conclusion: This first report outlines the consecution of the Brazilian surgical cardiac database, intended to serve primarily as a tool for providing information for clinical improvement and patient safety and constitute a basis for production of research protocols.Univ Fed Sao Paulo UNIFESP EPM, Hosp Sao Paulo, Sao Paulo, SP, BrazilHosp Caridade Sao Vicente Paulo, Jundiai, SP, BrazilInst Med Integral Prof Fernando Figueira IMIP, Recife, PE, BrazilHosp Base FUNFARME & FAMERP, Sao Jose Do Rio Preto, SP, BrazilIMC, Sao Jose Do Rio Preto, SP, BrazilIrmandade Santa Casa Sao Paulo INCT HPV, Fac Ciencias Med Santa Casa Sao Paulo, Sao Paulo, SP, BrazilFundacao Univ Cardiol, Inst Cardiol Rio Grande do Sul, Porto Alegre, RS, BrazilInst Coracao Natal, Natal, RN, BrazilInst Cardiol Dist Fed, Brasilia, DF, BrazilUniv Fed Maranhao HU UFMA, Univ Hosp, Sao Luis, MA, BrazilHosp Evangelico, Cachoeiro De Itapemirim, ES, BrazilHosp Coracao Sergipe, Aracaju, SE, BrazilHosp Nossa Senhora Salete, Inst Cirurgia Cardiovasc ICCV, Cascavel, PR, BrazilHosp Wilson Rosado, Mossoro, RN, BrazilHosp Bosque Saude, Sao Paulo, SP, BrazilHosp Univ Santa Maria, Santa Maria, RS, BrazilHosp Coracao HCor, Sao Paulo, SP, BrazilHosp Coracao IP HCor, Ins Pesquisa, Sao Paulo, SP, BrazilInst Coracao InCor, Sao Paulo, SP, BrazilUniv Fed Sao Paulo UNIFESP EPM, Hosp Sao Paulo, Sao Paulo, SP, BrazilWeb of Scienc
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