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1.
J Interv Cardiol ; 2022: 4368887, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35600211

RESUMO

Transcatheter aortic valve replacement (TAVR) to treat degeneration of bioprosthetic heart valves (BHVs), called as valve-in-valve (ViV), is becoming a key feature since the number of BHVs requiring intervention is increasing and many patients are at high risk for a redo cardiac surgery. However, a TAVR inside a small previous cardiac valve may lead to prosthesis-patient mismatch (PPM) and not be as effective as we hoped for. An effective option to decrease the chance of PPM is to fracture the previous heart valve implanted using a high-pressure balloon. By performing a valve fracture, the inner valve ring of small BHVs can be opened up by a single fracture line, allowing subsequent implantation of a properly sized transcatheter heart valve, without increasing substantially the procedure risk. In this article, we provide a step-by-step procedure on how to safely and properly fracture a BHV and report a case of a TAVR in a degenerated rapid deployment valve.


Assuntos
Estenose da Valva Aórtica , Bioprótese , Implante de Prótese de Valva Cardíaca , Próteses Valvulares Cardíacas , Substituição da Valva Aórtica Transcateter , Valva Aórtica/cirurgia , Estenose da Valva Aórtica/cirurgia , Bioprótese/efeitos adversos , Próteses Valvulares Cardíacas/efeitos adversos , Implante de Prótese de Valva Cardíaca/efeitos adversos , Humanos , Desenho de Prótese , Falha de Prótese , Substituição da Valva Aórtica Transcateter/efeitos adversos , Resultado do Tratamento
2.
Phys Chem Chem Phys ; 24(23): 14631-14639, 2022 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-35670365

RESUMO

The gas-phase reactions of noble gas (Ng) cations, namely Kr+ and Xe+, with SF6 were investigated experimentally by Fourier transform ion cyclotron resonance mass spectrometry and computationally using RI-MP2 and BCCD(T) methods. The study revealed a new interaction between Kr+ and neutral SF6 that gave rise to a new cationic, weakly bound complex of Kr, [KrSF5]+, although the major reaction channel was dissociative electron transfer to yield SF5+ and {Kr, F}. Experimental studies examined the formation and stability of the new species and computational studies addressed the energetics of the reaction and indicated that [KrSF5]+ is stable by ca. 1 kcal mol-1. The same computational approach was used to examine the reaction of Xe+ with SF6 and showed it to be thermodynamically unfavourable by ca. 35 kcal mol-1, confirming the non-observation of reaction in the mass spectrometry experiments. An analysis of the bonding in [KrSF5]+ clearly showed that it is a non-covalently bound species, while in its presumed precursor [KrSF6]+ a partially covalent Kr-F bond is present.

3.
Ann Vasc Surg ; 72: 666.e23-666.e32, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33333194

RESUMO

Saccular superior vena cava aneurysms (SVCAs) are one of the rarest causes of mediastinal masses. Seventy years after the first published case report, to the best of our knowledge, fewer than 30 cases have been described in the literature. This article provides an overview of the peculiarities regarding diagnosis and treatment performed in these cases and addresses the protocol adopted in our case report. We present a saccular aneurysm resected through median sternotomy, under cardiopulmonary bypass and superior vena cava reconstruction using a bovine pericardial patch.


Assuntos
Aneurisma/cirurgia , Pericárdio/transplante , Procedimentos de Cirurgia Plástica , Procedimentos Cirúrgicos Vasculares , Veia Cava Superior/cirurgia , Adolescente , Adulto , Idoso , Aneurisma/diagnóstico por imagem , Animais , Ponte Cardiopulmonar , Bovinos , Feminino , Xenoenxertos , Humanos , Masculino , Pessoa de Meia-Idade , Esternotomia , Resultado do Tratamento , Veia Cava Superior/diagnóstico por imagem , Adulto Jovem
4.
Molecules ; 26(16)2021 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-34443420

RESUMO

Searching in the Web of Knowledge for "ionic liquids" AND "luminescence" AND "lanthanide", around 260 entries can be found, of which a considerable number refer solely or primarily to europium (90%, ~234). Europium has been deemed the best lanthanide for luminescent applications, mainly due to its efficiency in sensitization, longest decay times, and the ability to use its luminescence spectra to probe the coordination geometry around the metal. The remaining lanthanides can also be of crucial importance due to their different colors, sensitivity, and capability as probes. In this manuscript, we intend to shed some light on the existing published work on the remaining lanthanides. In some cases, they appear in papers with europium, but frequently in a subordinate position, and in fewer cases then the main protagonist of the study. All of them will be assessed and presented in a concise manner; they will be divided into two main categories: lanthanide compounds dissolved in ionic liquids, and lanthanide-based ionic liquids. Finally, some analysis of future trends is carried out highlighting some future promising fields, such as ionogels.

5.
Phys Chem Chem Phys ; 20(15): 9838-9846, 2018 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-29610796

RESUMO

Ionic-liquid-based acidic aqueous biphasic systems (IL-based AcABS) represent a promising alternative to the solvent extraction process for the recovery of critical metals, in which the substitution of the inorganic salt by an acid allows for a 'one-pot' approach to the leaching and separation of metals. However, a more fundamental understanding of AcABS formation remains wanting. In this work, the formation mechanisms of AcABS are elucidated through a comparison with traditional aqueous biphasic systems (ABS). A large screening of AcABS formation with a wide range of IL identifies the charge shielding of the cation as the primary structural driver for the applicability of an IL in AcABS. Through a systematic study of tributyltetradecylphosphonium chloride ([P44414]Cl) with various chloride salts and acids, we observed the first significant deviation to the cationic Hofmeister series reported for IL-based ABS. Furthermore, the weaker than expected salting-out ability of H3O+ compared to Na+ is attributed to the greater interaction of H3O+ with the [P44414]+ micelle surface. Finally, the remarkable thermomorphic properties of [P44414]Cl based systems are investigated with a significant increase in the biphasic region induced by the increase in the temperature from 298 K to 323 K. These finding allows for the extension of ABS to new acidic systems and highlights their versatility and tunability.

6.
Chemphyschem ; 16(9): 1969-77, 2015 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-25891168

RESUMO

Gas-phase affinity studies based on cations and anions commonly present in ionic liquid structures, give quantitative information about the magnitude of the interactions holding the two species together when ILs are formed. They also provide clues on how these interactions depend on the nature of the cationic and anionic moieties. In the present work, mass spectrometric experiments, performed using electrospray ionization quadrupole ion-trap and Fourier transform ion cyclotron resonance mass spectrometry, were used to obtain two affinity scales by Cooks' kinetic method: one scale for the various cations for the bis(trifluoromethylsulfonyl)imide anion, [NTf2 ](-) , and another for the different anions for the 1-butyl-3-methylimidazolium cation, [C4 mim](+) . The obtained results are compared with previously reported data and discussed in terms of the structural characteristics of the different cationic and anionic species.

7.
Ecology ; 94(9): 1977-85, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24279269

RESUMO

The relative importance of species richness and identity for the diversity-function relationship remains controversial. We mechanistically explored the potential contribution of ecosystem processes complexity (EPC; i.e., the number of pathways and mechanisms through which an ecosystem process can be directly and/or indirectly affected by species and/or their interactions) to the resolution of this controversy. We hypothesized that the complementarity effects of biodiversity will be stronger and that the diversity-function relationship will be more dependent on species richness as the EPC increases. Using a benthic bioturbator community as a model system we tested these predictions across ecosystem processes that could be ordered according to their complexity (suspended material flux < PO4-P flux < NH4-N flux < bacterioplankton production). Consistent with our predictions, species richness explained an increasing proportion of data variation as EPC increased, whereas the contrary was observed for species composition. Nontransgressive overyielding was not affected by EPC, but the magnitude of transgressive overyielding increased significantly with EPC, indicating that complementarity may be stronger as EPC increases. Our results highlight the importance of considering the interactive role of the characteristics of ecosystem processes in our theoretical understanding of the diversity-function relationship and its underlying mechanisms.


Assuntos
Biodiversidade , Invertebrados/fisiologia , Adaptação Fisiológica , Animais , Especificidade da Espécie
8.
Heliyon ; 9(11): e21479, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37954395

RESUMO

The wind power sector is experiencing rapid growth, which creates new challenges for its electricity grid integration. Accurate wind power forecasting (WPF) is crucial for trading, balancing, and dispatching wind energy. In this paper, we examine the use of aggregated turbine- and farm-level WPFs in the Nordic energy market. The turbine-level WPFs were retrieved from a previous study, while the farm-level WPFs were developed using the same methodology, incorporating inputs from three different numerical weather predictions (NWPs) and implementing both direct and indirect forecasting approaches. In the indirect WPF approach, we explore the impact of using wind direction as an input for the wind farm-level power performance model. The different WPFs are combined into one using weights related to up-to-date forecast errors. An automated and optimized machine-learning pipeline using data from a Norwegian wind farm is used to implement the proposed forecasting methods. The indirect approach, that uses the wind-downscaling model, improves the wind speed forecast accuracy compared to raw forecasts from the relevant NWPs. Additionally, we observed that the farm-level downscaling model exhibited lower error than those developed at the turbine level. The combined use of multiple NWP sources reduced forecasting errors by 8 %-30 % for direct and indirect WPFs, respectively. Direct and indirect forecasting methods present similar performance. Finally, the aggregated turbine-level improved WPF accuracy by 10 % and 15 % for RMSE and MAE, respectively, compared to farm-level WPF.

9.
Membranes (Basel) ; 13(5)2023 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-37233528

RESUMO

Lanthanides are critical elements, and their recovery from wastewater increases the availability of these elements and reduces their impacts on the environment. In this study, tentative approaches to extract lanthanides from low-concentration aqueous solutions were investigated. PVDF membranes soaked with different active compounds or synthesized chitosan-based membranes containing these active compounds were used. The membranes were immersed in 10-4 M of aqueous solutions of selected lanthanides, and their extraction efficiency was assessed using ICP-MS. The PVDF membranes showed quite poor results, with only the membrane with oxamate ionic liquid giving some positive results (0.75 mg of Yb, 3 mg of lanthanides per gram of membrane). However, the chitosan-based membranes led to very interesting results, with the maximum concentration factor for the final solution relative to the initial solution being 13 times higher for Yb, which was obtained with the chitosan-sucrose-citric acid membrane. Several of the chitosan membranes, namely the one with 1-Butyl-3-methylimidazolium-di-(2-ethylhexyl)-oxamate, could extract around 10 mg of lanthanides per gram of membrane, with the better one being the membrane with sucrose/citric acid that achieved more than 18 mg/g of membrane. The use of chitosan for this purpose is a novelty. Since these membranes are easily prepared and have a very low cost, practical applications can be envisaged after further studies to better understand the underlying mechanism.

10.
Oral Maxillofac Surg ; 2023 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-37847424

RESUMO

This case report presents a mandible reconstruction with temporomandibular joint (TMJ) prothesis for treatment of osteomyelitis infection following a bimaxillary orthognathic and genioplasty surgeries. The patient, a 41-year-old female, presented with facial pain, difficulty in opening her mouth, and mandibular deviation four months after the initial orthognathic surgery. During the four months, the patient had experienced two more surgerys post-operative for treatment of the complications. Examination revealed mobility between osteotomy segments of the right mandibular osteotomomie between body and ramus, and Computer Tomographic scan analysis revealed osteomyelitis and non-union within the osteotomy side of the right mandible from the previous surgery. Due to the advanced state of the disease and significant bone resorption, treatment was planned in two stages, involving bone debridement and then reconstruction with a custom made extended temporomandibular joint prosthesis. The patient had no postoperative complications and achieved satisfactory functional and aesthetic outcomes. This case emphasizes the importance of careful monitoring and prompt management of postoperative complications following orthognathic surgery to prevent rare but serious complications such as osteomyelitis.

11.
Biomedicines ; 11(12)2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-38137416

RESUMO

It has increasingly been recognized that electrical currents play a pivotal role in cell migration and tissue repair, in a process named "galvanotaxis". In this review, we summarize the current evidence supporting the potential benefits of electric stimulation (ES) in the physiology of peripheral nerve repair (PNR). Moreover, we discuss the potential of piezoelectric materials in this context. The use of these materials has deserved great attention, as the movement of the body or of the external environment can be used to power internally the electrical properties of devices used for providing ES or acting as sensory receptors in artificial skin (e-skin). The fact that organic materials sustain spontaneous degradation inside the body means their piezoelectric effect is limited in duration. In the case of PNR, this is not necessarily problematic, as ES is only required during the regeneration period. Arguably, piezoelectric materials have the potential to revolutionize PNR with new biomedical devices that range from scaffolds and nerve-guiding conduits to sensory or efferent components of e-skin. However, much remains to be learned regarding piezoelectric materials, their use in manufacturing of biomedical devices, and their sterilization process, to fine-tune their safe, effective, and predictable in vivo application.

12.
Pharmaceutics ; 14(12)2022 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-36559232

RESUMO

Frequently, deep partial and full-thickness skin wounds do not spontaneously regenerate. To restore the normal function of skin, epidermal and dermal components have to be supplied to the wound bed by grafting various substrates. Available options are limited and frequently costly. Herein, authors present a possible approach using 3D skin scaffolds capable of mimicking structure and biological functions of the extracellular matrix, providing, in parallel, a good environment for cell attachment, proliferation and differentiation. Low-molecular weight chitosan-based membranes were prepared by freeze-drying and ionizing radiation techniques to be used as skin scaffolds. Poly (vinyl alcohol), PVA, vinyl pyrrolidone, VP, and gelatin from cold water fish were incorporated. Information regarding membranes' physical-chemical properties from SEM analysis, swelling and weight loss, together with biological response through in vitro assays (using Human Caucasian Fetal Foreskin Fibroblast) allowed the selection of an optimized batch of membranes that was used as skin scaffold in a dorsal rat model wound. The in vivo implantation assays (in Wistar rats) resulted in very promising results: (i) healing process faster than control; (ii) good vascularization; (iii) viable new tissues morphologically functional.

13.
Membranes (Basel) ; 11(8)2021 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-34436324

RESUMO

Some of the current strategies for the development of scaffolding materials capable of inducing tissue regeneration have been based on the use of polymeric biomaterials. Chitosan, in particular, due to its recognized biological activity has been used in a number of biomedical applications. Aiming the development of chitosan-based membranes with improved cell adhesion and growth properties to be used as skin scaffolds allowing functional tissue replacement, different formulations with chitosan of different molecular weight, poly (vinyl alcohol) and gelatin, were evaluated. To meet the goal of getting ready-to-use scaffolds assuring membranes' required properties and sterilization, preparation methodology included a lyophilization procedure followed by a final gamma irradiation step. Two radiation dose values were tested. Samples were characterized by TGA, FTIR, and SEM techniques. Their hydrophilic properties, in vitro stability, and biocompatibility were also evaluated. Results show that all membranes present a sponge-type inner structure. Chitosan of low molecular weight and the introduction of gelatin are more favorable to cellular growth leading to an improvement on cells' morphology and cytoskeletal organization, giving a good perspective to the use of these membranes as potential skin scaffolds.

14.
Braz J Cardiovasc Surg ; 36(4): 500-505, 2021 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-33656831

RESUMO

INTRODUCTION: Use of bilateral internal thoracic artery (BITA) as graft in coronary artery bypass grafting (CABG) is controversial because it is related to higher in-hospital mortality, incidence of sternal wound-related infection, and an increase in surgical time. The primary objective of this study is to evaluate in-hospital mortality and mortality within 30 days from discharge. The secondary objective is to evaluate the occurrence of deep sternal wound infection in a 90-day follow-up. METHODS: This is a retrospective review of the medical records of 152 patients undergoing elective CABG with the use of BITA and cardiopulmonary bypass (CPB). These patients were divided into two groups, diabetics and non-diabetics. Patients with acute myocardial infarction and concomitant valvular disease were not included in the sample. RESULTS: Preoperative characteristics did not show significant differences between the groups, which allowed a comparative analysis. The variables electrocardiography time and aortic clamping time were higher in the diabetic group, with a significant statistical difference (P<0.0001). In-hospital mortality occurred in three patients, and there was no mortality up to 30 days in both groups. There was no significant difference in the primary end point between groups (P=0.56). Deep sternal wound infection was present in only one patient and showed no significant difference in the secondary outcome between groups (P=0.40). CONCLUSION: We did not observe a higher mortality and occurrence of deep sternal wound infection with the use of BITA in diabetic patients compared to non-diabetics, even with greater CPB and aortic clamping times in diabetics.


Assuntos
Doença da Artéria Coronariana , Diabetes Mellitus , Artéria Torácica Interna , Doença da Artéria Coronariana/cirurgia , Humanos , Revascularização Miocárdica , Estudos Retrospectivos , Fatores de Risco , Infecção da Ferida Cirúrgica/etiologia , Resultado do Tratamento
15.
Artigo em Inglês | MEDLINE | ID: mdl-33925412

RESUMO

The COVID-19 pandemic has important consequences for the mental health of populations. Patients with cancer, already at risk for poor mental health outcomes, are not expected to be spared from these consequences, prompting the need for health services to improve responsiveness. This article presents the research protocol for an implementation study designed to describe the uptake of a well-studied and recognized system for the treatment of depression and anxiety (Stepped-care) during the specific context of a Pandemic in an oncological site. The system set-up will be assisted by a digital platform (MoodUP), where patients undergoing cancer treatment will be screened for anxiety and depressive symptoms, triaged by severity level and algorithm-matched to recommended interventions. Patients undergoing cancer treatment at a cancer clinic in Portugal will be invited to subscribe to the MoodUP platform where they will complete a self-reported questionnaire (Hospital Anxiety and Depression Scale) to screen their anxiety and depressive symptoms. Data will be instantly collected, and an algorithm will activate severity-matched intervention suggestions, through a case manager that will coordinate care. The specific objectives of this study will be to describe the implementation and acceptability of the care system by patients and staff, the barriers to and facilitators of implementation, the proportion of patients accessing the system and their pathways through the various stepped-care interventions, and patient perceptions regarding the feasibility and appropriateness of the eHealth platform. Moreover, exploratory analyses will be conducted to describe patterns of anxiety and depression symptoms variation across all patients, as well as within sociodemographically, clinically and contextually characterized subgroups, to characterize their care needs and access, as well as to explore for whom the MoodUP care system may be more appropriate. This study is expected to improve processes for collaborative mental healthcare in oncology and accelerate the digitalization of services, towards the improvement of mental healthcare access, and management of high-risk patients, during the COVID-19 pandemic.


Assuntos
COVID-19 , Neoplasias , Humanos , Saúde Mental , Neoplasias/epidemiologia , Neoplasias/terapia , Pandemias , Portugal/epidemiologia , SARS-CoV-2
16.
Chemphyschem ; 11(17): 3673-7, 2010 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-21058381

RESUMO

The vaporization of a dicationic ionic liquid at moderate temperatures and under reduced pressures--recently studied by line-of-sight mass spectrometry--was further analyzed using an ion-cyclotron resonance mass spectroscopy technique that allows the monitoring of the different species present in the gas phase through the implementation of controlled ion-molecule reactions. The results support the view that the vapour phase of an aprotic dicationic ionic liquid is composed of neutral ion triplets (one dication attached to two anions). Molecular dynamics simulations were also performed in order to explain the magnitude of the vaporization enthalpies of dicationic ionic liquids vis-à-vis their monocationic counterparts.

17.
Heart Surg Forum ; 13(1): E17-20, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20150033

RESUMO

BACKGROUND: The aim of this study was to assess by Doppler echocardiography (ECO) the functioning of the mitral valve apparatus in patients who have undergone implantation of standardized bovine pericardium chordae (SBPC) for replacement of ruptured or elongated chordae tendineae with significant thinning. METHODS: SBPC were implanted in 31 patients who had mitral insufficiency due to rupture of chordae tendinae or elongated chordae with significant thinning. Patient ages ranged from 19 to 85 years (mean of 58 years). The most frequent cause of mitral insufficiency was fibroelastic degeneration in 25 patients (80.6%). The SBPC were fashioned as a set, joined at their extremities by 2 polyester-reinforced rods forming a monobloc. The SBPC were 2-mm wide and were positioned parallel to one another at a distance of 3 mm. Each set of SBPC had a corresponding measurer, and their length ranged from 20 to 35 mm. In 21 patients (67.7%) the SBPC were implanted in the posterior leaflet and in 10 patients (32.3%) in the anterior leaflet (in 2 patients concurrently in the anterior and posterior leaflets). All patients were assessed by ECO postoperatively, with a 20-month mean follow-up time (range 6-45 months). RESULTS: One patient (3.2%) died of pulmonary embolism during the early postoperative period. Postoperative ECO showed absence of mitral regurgitation in 17 patients (54.8%), mild regurgitation in 9 (29.0%), and mild-to-moderate regurgitation in 4 (12.9%). Opening and mobility of the mitral valve were normal in the 30 surviving patients. CONCLUSION: The ECO revealed good functionality of the mitral valve apparatus with appropriate leaflet coaptation in patients who had undergone implantation of SBPC for replacement of ruptured or elongated and thinned chordae. A longer follow-up is required to assess absence of calcification and/or degeneration of the SBPC.


Assuntos
Cordas Tendinosas/diagnóstico por imagem , Cordas Tendinosas/transplante , Ruptura Cardíaca/etiologia , Ruptura Cardíaca/cirurgia , Insuficiência da Valva Mitral/complicações , Insuficiência da Valva Mitral/cirurgia , Adulto , Idoso , Animais , Bovinos , Feminino , Ruptura Cardíaca/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Insuficiência da Valva Mitral/diagnóstico por imagem , Ruptura Espontânea/diagnóstico por imagem , Ruptura Espontânea/cirurgia , Resultado do Tratamento , Ultrassonografia
18.
Materials (Basel) ; 13(23)2020 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-33261106

RESUMO

Here we discuss the influence of two different cations on the emissive properties of the highly emissive [Eu(fod)4]- anion. The studied Eu(III) salts were [C16Pyr][Eu(fod)4] (1), and the previously reported [Chol][Eu(fod)4]. C16Pyr stands for N-cetylpyridinium, Chol for cholinium and fod for 1,1,1,2,2,3,3-heptafluoro-7,7-dimethyloctane-4,6-dionate. 1 is classified as ionic liquid, with melting point close to 60 °C, and presented a luminescence quantum yield of (ϕ) 100%. Ultrabright emissive photopolymers were obtained for the first time using polysulfone as the host matrix. The films were prepared with incorporation of 10% (w/w) of 1 and [Chol][Eu(fod)4] in the polymeric matrix, which improved its thermal stability. Additionally, the luminescence of CholEu(fod)4/PSU presented a strong temperature dependence with a ratiometric thermal behavior.

19.
Chempluschem ; 85(12): 2629-2635, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33274839

RESUMO

An emissive europium(III) complex [C2 mim][Eu(fod)4 ] (1; C2 mim=1-ethyl-3-methyl-imidazolium; fod=1,1,1,2,2,3,3-heptafluoro-7,7-dimethyloctane-4,6-dionate) was prepared. The complex shows ratiometric thermal behaviour up to 155 °C. These unusual temperature-dependent properties arise from a solid-solid phase transition that promotes increased contact between the anion and the cation, affecting the emission profile of the emissive anion in two different ratiometric relations. A ultrabright and flexible emissive photopolymer film was obtained using polysulfone (PSU) as the host matrix of 10 % (w/w) of 1, that also induced changes on the lanthanide emissive profile with temperature. A temperature-responsive luminescent film 1/PSU is sensitivr to heating between 100 and 155 °C. Also, the emission lifetime of 1 was not affected by confinement in PSU, while its emission quantum yield was reduced from 82 to 59 %.

20.
J Phys Chem B ; 113(11): 3491-8, 2009 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-19278265

RESUMO

Fourier transform ion cyclotron resonance mass spectrometry experiments showed that liquid Group 1 metal salts of the bistriflamide anion undergoing reduced-pressure distillation exhibit a remarkable behavior that is in transition between that of the vapor-liquid equilibrium characteristics of aprotic ionic liquids and that of the Group 1 metal halides: the unperturbed vapors resemble those of aprotic ionic liquids, in the sense that they are essentially composed of discrete ion pairs. However, the formation of large aggregates through a succession of ion-molecule reactions is closer to what might be expected for Group 1 metal halides. Similar experiments were also carried out with bis{(trifluoromethyl)sulfonyl}amine to investigate the effect of H(+), which despite being the smallest Group 1 cation, is generally regarded as a nonmetal species. In this case, instead of the complex ion-molecule reaction pattern found for the vapors of Group 1 metal salts, an equilibrium similar to those observed for aprotic ionic liquids was observed.


Assuntos
Amidas/química , Hidrocarbonetos Fluorados/química , Íons/química , Metais/química , Sais/química , Algoritmos , Ânions , Espectroscopia de Ressonância Magnética , Pressão , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Termodinâmica
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