Zeólitos sodalite emissivos para aplicação em iluminação

Atualmente, a população está cada vez mais dependente da iluminação, usando-a intensamente no seu quotidiano. O desenvolvimento de LEDs revolucionou este campo, devido às suas altas eficiências energéticas e baixos consumos. Na produção de LEDs normalmente são utilizados phosphors, que têm na sua composição mariotariamente terras-raras, cuja utilização se prevê muito limitada a curto prazo, tornando-se essencial o estudo de outros materiais para utilizar como phosphors. As alternativas podem passar pelo uso de zeólitos luminescentes, que apresentam rendimentos quânticos na ordem dos 97%. Os zeólitos sodalite também demonstram propriedades interessantes, tais como rendimentos quânticos de 53%, desvios de Stokes de 250 nm e estabilidade térmica até aos 450 ºC. A hackmanite é um mineral de sodalite natural com enxofre na sua composição e uma fórmula química de Na8[SiAlO4]6(Cl,S)2, podendo ser sintetizada em laboratório através de uma síntese em estado sólido, partindo do zeólito LTA. Com o objetivo de alargar a aplicabilidade destes zeólitos sodalite, foram feitas várias sínteses em atmosfera redutora com diferentes concentrações de enxofre e diferentes halogéneos, alterou-se também o calcogénio e, por fim, foram introduzidos metais na sua estrutura. As espécies fotoluminescentes S2- e Se2- foram encontradas nestas sodalites com desvios de Stokes de cerca de 250 nm, máximos de intensidade de emissão aos 650 nm e 740 nm e rendimentos quânticos de 46% e 48%, respetivamente. Com a introdução da prata na estrutura da sodalite, obtiveram-se compostos com luminescência branca. Também se introduziu chumbo, obtendo-se um desvio do espetro de emissão com um máximo de intensidade aos 610 e aos 680 nm, respetivamente para as espécies S2- e Se2-. Estes zeólitos sodalite mostraram ser bastante promissores na substituição dos phosphors de LEDs comerciais devido às suas propriedades óticas. Os zeólitos resultantes da interação com o chumbo podem ainda ser utilizados em concentradores solares luminescentes

Long-lived NIR emission in sulfur-doped zeolites due to the presence of [S3]2- clusters

Funding Information: The authors want to acknowledge the Portuguese Foundation for Science and Technology for funding through the grants SFRH/BD/145009/2019 and SFRH/BPD/120599/2016 , the individual contract 2020.00252. CEECIND and several projects PTDC/QUI-QFI/32007/2017, UIDB/04565/2020, UIDP/04565/2020, LA/P/0140/2020, LAQV-REQUIMTE (LA/P/0008/2020, UIDB/50006/2020 and UIDP/50006/2020), VICARTE (UIDP/00729/2020, UIDB/00729/2020) and C2TN (UIDB/04349/2020). MOSTMICRO-ITQB R&D Unit (UIDB/04612/2020, UIDP/04612/2020) and LS4FUTURE Associated Laboratory (LA/P/0087/2020) and by European Union's Horizon 2020 research and innovation program under grant agreement No. 810856. Funding Information: The authors want to acknowledge the Portuguese Foundation for Science and Technology for funding through the grants SFRH/BD/145009/2019 and SFRH/BPD/120599/2016, the individual contract 2020.00252. CEECIND and several projects PTDC/QUI-QFI/32007/2017, UIDB/04565/2020, UIDP/04565/2020, LA/P/0140/2020, LAQV-REQUIMTE (LA/P/0008/2020, UIDB/50006/2020 and UIDP/50006/2020), VICARTE (UIDP/00729/2020, UIDB/00729/2020) and C2TN (UIDB/04349/2020). MOSTMICRO-ITQB R&D Unit (UIDB/04612/2020, UIDP/04612/2020) and LS4FUTURE Associated Laboratory (LA/P/0087/2020) and by European Union's Horizon 2020 research and innovation program under grant agreement No. 810856. Publisher Copyright: © 2023 The Author(s)The exploration of novel long-lived near-infrared (NIR) luminescent materials has attracted significant attention due to their applications in optical communications, anticounterfeiting, and bioimaging. However, these materials usually present low photoluminescence quantum yields and low photo- and chemical stability. Novel emitters that overcome these limitations are in demand. In this study, NIR emission was achieved using widely available, sustainable, and non-toxic materials through the synthesis of sulfur-doped zeolites, with different S/Cl ratios. With a combination of computational calculations (TD-DFT) and spectroscopic data, this emission was assigned to the radiative decay of excited triplet states of [S3]2- clusters, which resulted in a remarkably high Stokes shift (1.97 eV, 440 nm) and an average decay time of 0.54 ms. These new materials present high stability, external quantum efficiency of up to 17%, and a long-lived NIR emission, placing these compounds in a unique position to be used in applications demanding NIR emitters.publishersversionpublishe

Tricarbonyl M(I) (M = Re, 99mTc) complexes bearing acridine fluorophores : synthesis, characterization, DNA interaction studies and nuclear targeting

© The Royal Society of Chemistry 2010New pyrazolyl-diamine ligands with acridine derivatives at the 4-position of the pyrazolyl ring were synthesized and characterized (L1 and L2). Coordination towards the fac-[M(CO)3]+ (M = Re, 99mTc) led to complexes fac-[M(CO)3(κ3-L)] (L = L1: M = Re1, Tc1; L = L2: M = Re2, Tc2). The interaction of the novel pyrazolyl-diamine ligands (L1 and L2) and rhenium(I) complexes (Re1 and Re2) with calf thymus DNA (CT-DNA) was investigated by a variety of techniques, namely UV-visible , fluorescence spectroscopy and circular and linear dichroism . Compounds L1 and Re1 have moderate affinity to CT-DNA and bind to DNA by intercalation, while L2 and Re2 have a poor affinity for CT-DNA. Moreover, LD measurements showed that L1 and Re1 act as perfect intercalators . By confocal fluorescence microscopy we found that L1 and Re1 internalize and localize in the nucleus of B16F1 murine melanoma cells . The congener Tc1 complex also targets the cell nucleus exhibiting a time-dependent cellular uptake and a fast and high nuclear internalization (67.2% of activity after 30 min). Plasmid DNA studies have shown that Tc1 converts supercoiled (sc) puc19 DNA to the open circular (oc) form.Teresa Esteves and Sofia Gama thank the FCT for a doctoral and postdoctoral research grants (SFRH/BD/29154/2006 and SFRH/BPD/29564/2006, respectively). COST Action D39 is also acknowledge. The QITMS instrument was acquired with the support of the Programa Nacional de Reequipamento Científico (Contract>REDE/1503/REM/2005-ITN) of Fundação para a Ciência e a Tecnologia and is part of RNEM - Rede Nacional de Espectrometria de Massa

Multifunctionality of the [C2mim][Ln(fod)4] series (Ln = Nd-Tm except Pm):magnetic, luminescent and thermochemical studies

A series of nine tetrakis lanthanide β-diketonate complexes of the type [C2mim][Ln(fod)4] (C2mim = 1-ethyl-3-methylimidazolium, fod = 6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedionate) were prepared, with yields above 80%, and their thermochemical, photophysical and magnetic susceptibilities were evaluated. Thermochemical studies presented a rare and reversible conversion between two solid phases (polymorphism), characteristic of the [Ln(fod)4]− anion. Photophysical and magnetic studies revealed that Dy and Er presented the multifunctionality of being simultaneously SMMs and visible (Dy) or near infra-red (Er) emitters. The Nd, Ho and Tm analogues present characteristic emission bands in the NIR region (800–1200 nm), while Sm, Eu, Tb and Dy present emissions in the visible range. Magnetic susceptibility of Tb, Dy, Ho, Er and Tm salts were measured in the temperature range of 2–300 K, showing paramagnetic behaviour, although with different regimes, with AC susceptibility measurements, at different frequencies in the range of 10–10 000 Hz, providing evidence of slow magnetic relaxation processes for Gd, Dy and Er analogues with SMM behavior.publishe

Do Hóquei em Patins à Arquitetura. Questões sobre a correlação entre 'Improviso' e 'Estratégia Prévia', no projeto como jogo

À ideia de conceção da Arquitetura está inerente o conceito transdisciplinar e pluridimensional, que confere a esta disciplina uma magnitude que se estende ao domínio artístico, programático, científico, humano e referente a diversas áreas do conhecimento. Esta característica resulta em possibilidades de dilatação recorrentes, a nível prático e a nível teórico, o que promove o aparecimento de novas perspetivas relativas a todos os aspetos, pontos de vista, questões e entendimentos da Arquitetura. Introduzida pelo contexto do paradigma atual, esta reflexão observa a Arquitetura através de uma nova lente, que a associa ao conceito de jogo, evidenciando uma posição que requer uma explicitação inicial que permita entender o ponto de vista que se estabelece. Contextualizado pelas problemáticas do autoral, da mestria e das diferentes dimensões do conhecimento, o panorama reflexivo assenta, por sua vez, na possibilidade de cruzar os mundos da Arquitetura e do Hóquei em Patins a nível contextual, conceptual, metodológico e sensorial. Tendo como ponto de partida o reconhecimento de diferenças e semelhanças, esta dissertação resulta do desenvolvimento de uma problemática que se acerca mais do que se distancia, apesar do seu carácter aparentemente pouco convencional. Colocar as práticas da Arquitetura e do Hóquei em Patins em confronto é reconhecer que o conceito de jogo que as une, associado naturalmente à impossibilidade de dissociação entre estratégia prévia/tática e improviso/técnica, abre portas ao entendimento da Arquitetura segundo um prisma que inclui temáticas como objetivo, competitividade, tomadas de decisão, resultados, técnica, tática ou risco - o que se pode assumir como, no mínimo, invulgar. Para além disso, o recurso à exemplificação é bastante utilizado pela facilidade de interassociação, o que permite um melhor esclarecimento das conclusões tiradas e pontos de vista colocados em evidência. Desde a ideia que une o jogo ao projeto, à identificação do adversário do arquiteto, procede-se à interseção de campos disciplinares distintos, reorganizando a informação considerada, de forma a que, daí, resulte uma análise conceptual fundamentada que permita o estudo do método projetual que pode, provavelmente, ser considerado viável segundo este panorama. Remata com a inignorável questão do espectador do jogo, e da multissensorialidade autoral para si e para com ele.Lying under the idea of Architectural conception, a multidimensional and transdisciplinary con-cept that grants the magnitude of this discipline is identifiable, conferring its extension through the ar-tistic, programmatic, scientific, human and many other knowledge-related domains. This distinctive and embracing configuration leads to endless expansion possibilities, which naturally become recurrent at theoretical and practical levels, and promote the turning up of new perspectives, points of view, prob-lematics and understandings of Architecture. Introduced by the context of the actual paradigm, this analysis can be considered as an obser-vation of Architecture through a new lens, which associates it to the game concept and emphasizes a position that requires an initial contextualization so that the full understanding of the matter becomes viable. Introduced by the author's problematic and the expertise required to master the different dimen-sions of knowledge, the brought-out perspective of this dissertation lies on the possibility of connecting Architecture and Rink Hockey, in their context, concept, method and sense. Starting with the recognition of the differences and similarities between these both worlds, this perspective sums up the development of an interdisciplinary analysis that brings together two different worlds, despite its (apparently) unconventional character. Facing up Architecture and Rink Hockey is understanding that the game concept that brings them closer, when naturally associated to the impos-sibility of separation between prior strategy (tactic) and improvisation (technique), brings up un under-standing of Architecture that develops under a new vision, one that includes matters and concepts such as goal, competitiveness, decision making, results, technique, tactic or risk - and this can be considered, at least, unusual. Moreover, the use of exemplification is quite frequent, since it provides easiness in the understanding of the different associations, and helps to apprehend the perspectives, conclusions and points of view that are progressively enunciated. From the idea of the elements that unite the game to the project, to the identification of the architect's opponent, these two distinct disciplines get intersected, the information gets reorganized, and the results lie on a reasonable conceptual analysis, which allows the studying and interpretation of a conceptional method of Architecture that is appropriate and relevant to the general presented panorama. It finishes with the unignorable comparison between the spectator of the game and the spectator of Architecture, allied with the multi-sensorial matter that concerns, not only him, but the author as well

Sex differences in mortality after acute myocardial infarction: changes from 1994 to 2006

BACKGROUND: Previous studies have shown that women younger than 55 years have higher hospital mortality rates after acute myocardial infarction (MI) than age-matched men. We examined whether such mortality differences have decreased in recent years. METHODS: We investigated temporal trends in the hospital case-fatality rates of MI by sex and age from June 1, 1994, through December 31, 2006. The study population included 916,380 patients from the National Registry of Myocardial Infarction with a confirmed diagnosis of MI. RESULTS: In-hospital mortality decreased markedly between 1994 and 2006 in all patients but more so in women than men. The mortality reduction in 2006 relative to 1994 was largest in women younger than 55 years (52.9%) and lowest in men younger than 55 years (33.3%). In patients younger than 55 years, the absolute decrease in mortality was 3 times larger in women than men (2.7% vs 0.9%). As a result, the excess mortality in younger women (\u3c55 years) compared with men was less pronounced in 2004-2006 (unadjusted odds ratio, 1.32; 95% confidence interval, 1.07-1.67) than it was in 1994-1995 (unadjusted odds ratio, 1.93; 95% confidence interval, 1.67-2.24). The sex difference in mortality decrease was lower in older patients (P = .004 for the interaction among sex, age, and year). Changes in comorbidity and clinical severity features at admission accounted for more than 90% of these mortality trends. CONCLUSIONS: In recent years, women, particularly younger ones, experienced larger improvements in hospital mortality after MI than men. The narrowing of the mortality gap between younger women and men is largely attributable to temporal changes in risk profiles

Relation of age and race with hospital death after acute myocardial infarction

BACKGROUND: Prior studies have suggested that young blacks with acute myocardial infarction (AMI) may have higher hospital mortality rates than whites of similar age. However, the influence of age and race on short-term death has not been explored in detail. We examined the relation of age and race on short-term death in a large AMI population and ascertained the factors that may have contributed to differences in mortality rates. METHODS: We compared the crude and adjusted hospital mortality rates stratified by age among 40,903 blacks and 501,995 whites with AMI enrolled in the National Registry of Myocardial Infarction-2 in 1482 participating US hospitals from June 1994 through March 1998. RESULTS: Overall crude mortality was lower among blacks compared with whites (10.9% vs 12.0%, P \u3c.0001). However, blacks had a significantly higher crude mortality rate compared with the whites in the age groups \u3c65 years (\u3c45 years, and 5-year age groups between 45 and 64 years). There was a statistically significant interaction between age and black race on hospital death (P value for interaction \u3c.001). Each 5-year decrement in age from 85 years was associated with 7.2% higher odds of death in blacks compared with whites (95% CI, 5.7% to 7.6%). After adjusting for differences in the baseline, clinical presentation, early treatment, and hospital characteristics, 5-year decrements in age was still associated with increases in the odds for death in blacks compared with whites (5.4%; 95% CI, 3.6% to 7.2%). This interaction between age and black race was present in both sexes but was stronger among men. CONCLUSIONS: Blacks younger than 65 years had higher hospital mortality rates compared with whites hospitalized for AMI, and decreasing age was associated with progressively higher risk of hospital death for blacks. Differences in the clinical presentation, early treatment, and hospital characteristics could only partly explain this age-race interaction

Determinants of appropriate use of angiotensin-converting enzyme inhibitors after acute myocardial infarction in persons \u3e or = 65 years of age

We sought to determine how often angiotensin-converting enzyme (ACE) inhibitors are prescribed as a discharge medication among eligible patients \u3e or = 65 years old with an acute myocardial infarction; to identify patient characteristics associated with the decision to prescribe ACE inhibitors; and to determine the factors associated with the decision to obtain an evaluation of left ventricular function among patients who have no contraindications to ACE inhibitors. We addressed these aims with an observational study of consecutive elderly Medicare beneficiary survivors of an acute myocardial infarction hospitalized in Alabama, Connecticut, Iowa, and Wisconsin between June 1992 and February 1993. Among the 5,453 patients without a contraindication to ACE inhibitors at discharge, 3,528 (65%) had an evaluation of left ventricular function. Of the 1,228 patients without a contraindication to ACE inhibitors who had a left ventricular ejection fraction \u3c or = 40%, 548 (45%) were prescribed the medication at discharge. In a multivariable analysis, an increased prescribed use of ACE inhibitors at discharge was correlated with several factors, including diabetes mellitus, congestive heart failure, ventricular tachycardia, and loop diuretics as a discharge medication. Patients admitted after the publication of the Survival and Ventricular Enlargement (SAVE) trial were significantly more likely to receive ACE inhibitors, although the absolute improvement in utilization was small in the 6 months after the trial results were published. In conclusion, improving the identification of appropriate patients for ACE inhibitors and increasing the prescription of ACE inhibitors for ideal patients may provide an excellent opportunity to improve care

Association of age and sex with myocardial infarction symptom presentation and in-hospital mortality

CONTEXT: Women are generally older than men at hospitalization for myocardial infarction (MI) and also present less frequently with chest pain/discomfort. However, few studies have taken age into account when examining sex differences in clinical presentation and mortality. OBJECTIVE: To examine the relationship between sex and symptom presentation and between sex, symptom presentation, and hospital mortality, before and after accounting for age in patients hospitalized with MI. DESIGN, SETTING, AND PATIENTS: Observational study from the National Registry of Myocardial Infarction, 1994-2006, of 1,143,513 registry patients (481,581 women and 661,932 men). MAIN OUTCOME MEASURES: We examined predictors of MI presentation without chest pain and the relationship between age, sex, and hospital mortality. RESULTS: The proportion of MI patients who presented without chest pain was significantly higher for women than men (42.0% [95% CI, 41.8%-42.1%] vs 30.7% [95% CI, 30.6%-30.8%]; P \u3c .001). There was a significant interaction between age and sex with chest pain at presentation, with a larger sex difference in younger than older patients, which became attenuated with advancing age. Multivariable adjusted age-specific odds ratios (ORs) for lack of chest pain for women (referent, men) were younger than 45 years, 1.30 (95% CI, 1.23-1.36); 45 to 54 years, 1.26 (95% CI, 1.22-1.30); 55 to 64 years, 1.24 (95% CI, 1.21-1.27); 65 to 74 years, 1.13 (95% CI, 1.11-1.15); and 75 years or older, 1.03 (95% CI, 1.02-1.04). Two-way interaction (sex and age) on MI presentation without chest pain was significant (P \u3c .001). The in-hospital mortality rate was 14.6% for women and 10.3% for men. Younger women presenting without chest pain had greater hospital mortality than younger men without chest pain, and these sex differences decreased or even reversed with advancing age, with adjusted OR for age younger than 45 years, 1.18 (95% CI, 1.00-1.39); 45 to 54 years, 1.13 (95% CI, 1.02-1.26); 55 to 64 years, 1.02 (95% CI, 0.96-1.09); 65 to 74 years, 0.91 (95% CI, 0.88-0.95); and 75 years or older, 0.81 (95% CI, 0.79-0.83). The 3-way interaction (sex, age, and chest pain) on mortality was significant (P \u3c .001). CONCLUSION: In this registry of patients hospitalized with MI, women were more likely than men to present without chest pain and had higher mortality than men within the same age group, but sex differences in clinical presentation without chest pain and in mortality were attenuated with increasing age