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2.
Environ Int ; 188: 108751, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38761430

RESUMO

Microplastics (MPs) are an everyday part of life, and are now ubiquitous in the environment. Crucially, MPs have not just been found within the environment, but also within human bodies, including the blood. We aimed to provide novel information on the range of MP polymer types present, as well as their size and shape characteristics, in human whole blood from 20 healthy volunteers. Twenty-four polymer types were identified from 18 out of 20 (90 %) donors and quantified in blood, with the majority observed for the first time. Using an LOQ approach, five polymer types met the threshold with a lower mean ± SD of 2466 ± 4174 MP/L. The concentrations of plastics analysed in blood samples ranged from 1.84 - 4.65 µg/mL. Polyethylene (32 %), ethylene propylene diene (14 %), and ethylene-vinyl-acetate/alcohol (12 %) fragments were the most abundant. MP particles that were identified within the blood samples had a mean particle length of 127.99 ± 293.26 µm (7-3000 µm), and a mean particle width of 57.88 ± 88.89 µm (5-800 µm). The MPs were predominantly categorised as fragments (88 %) and were white/clear (79 %). A variety of plastic additive chemicals were identified including endocrine disrupting-classed phthalates. The procedural blank samples comprised 7 polymer types, that were distinct from those identified in blood, mainly resin (25 %), polyethylene terephthalate (17 %), and polystyrene (17 %) with a mean ± SD of 4.80 ± 5.59 MP/L. This study adds to the growing evidence that MPs are taken up into the human body and are transported via the bloodstream. The shape and sizes of the particles raise important questions with respect to their presence and associated hazards in terms of potential detrimental impacts such as vascular inflammation, build up within major organs, and changes to either immune cell response, or haemostasis and thrombosis.


Assuntos
Microplásticos , Humanos , Microplásticos/análise , Polímeros , Adulto , Masculino , Feminino , Plásticos , Monitoramento Ambiental/métodos , Adulto Jovem , Tamanho da Partícula
3.
MethodsX ; 12: 102534, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38223219

RESUMO

Outdoor air pollution has been found to have a significant adverse effect on health. When the authors attempted to monitor air quality that cyclists or e-scooter users' breath during commuting in different locations for health and safety analysis, it was found that the existence of internal combustion engine (ICE) cars has a significant effect on the pollution levels and the monitoring process. To comprehensively study the effect of cars and traffic on air quality that cyclists and e-scooters users experience, a low-cost and reliable system was needed to detect the proximity of cars that have diesel or petrol engines. Video cameras can be used to visually detect vehicles, but in the modern age with the existence of many electric and hybrid vehicles and the need to reduce the cost of instrumentation, there was a need to determine the passing of vehicles near e-scooter and bike users from the combined engine and tires sounds. To address this issue, this study suggests a novel approach of using sound waves of internal combustion engines and tire sounds during the passing of cars, combined with AI techniques (neural networks), to detect the proximity of cars from cyclists and e-scooter users. Audio-visual data was collected using Go-Pro cameras in order to combine the data with GPS location and pollution levels. Geographical data maps were produced to demonstrate the density of cars that cyclists encounter when on or near the road. This method will enable air quality monitoring research to detect the existence of ICE cars for future correlation with measured pollution levels. The proposed method allows for:•The automated selection of sensitive features from sound waves to detect vehicles.•Low-cost hardware which is independent of orientation that can be integrated with other air quality and GPS sensors.•The successful application of sensor fusion and neural networks.

4.
ACS Chem Neurosci ; 13(16): 2473-2482, 2022 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-35892278

RESUMO

Aß oligomers play a central role in the neurodegeneration observed with Alzheimer's disease. Our laboratory has developed covalently stabilized trimers derived from residues 17-36 of Aß as model systems for studying Aß oligomers. In the current study, we apply the emerging techniques of fluorescence lifetime imaging microscopy (FLIM) and native mass spectrometry (native MS) to better understand the assembly and interactions of the oligomer model system 2AT-L in aqueous solutions and with cells. 2AT-L and fluorescently labeled 2AT-L analogues assemble in the membrane-like environment of SDS-PAGE, showing diffuse bands of oligomers in equilibrium. Native ion mobility-mass spectrometry (native IM-MS) of 2AT-L allows for the identification of discrete oligomers in solution and shows similar patterns of oligomer formation between 2AT-L and fluorescently labeled analogues. Fluorescence microscopy with SH-SY5Y cells reveals that fluorescently labeled 2AT-L analogues colocalize within lysosomes. FLIM studies with phasor analysis further elucidate the assembly of 2AT-L within cells and establish the occurrence of FRET, indicating the presence of oligomers within cells. Collectively, these multiple complementary techniques help better understand the complex behavior of the 2AT-L model system.


Assuntos
Doença de Alzheimer , Neuroblastoma , Peptídeos beta-Amiloides/química , Humanos , Espectrometria de Massas , Fragmentos de Peptídeos/química , Água/química
5.
J Chem Theory Comput ; 18(7): 4186-4202, 2022 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-35759470

RESUMO

Time-dependent density functional theory has become state-of-the-art for describing photophysical and photochemical processes in extended materials because of its affordable cost. The inclusion of exact exchange was shown to be essential for the correct description of the long-range asymptotics of electronic interactions and thus a well-balanced description of valence, Rydberg, and charge-transfer excitations. Several approaches for an efficient treatment of exact exchange have been established for the ground state, while implementations for excited-state properties are rare. Furthermore, the high computational costs required for excited-state properties in comparison to ground-state computations often hinder large-scale applications on periodic systems with hybrid functional accuracy. We therefore propose two approximate schemes for improving computational efficiency for the treatment of exact exchange. Within the auxiliary density matrix method (ADMM), exact exchange is estimated using a relatively small auxiliary basis and the introduced basis set incompleteness error is compensated by an exchange density functional correction term. Benchmark results for a test set of 35 molecules demonstrate that the mean absolute error introduced by ADMM is smaller than 0.3 pm for excited-state bond lengths and in the range of 0.02-0.04 eV for vertical excitation, adiabatic excitation, and fluorescence energies. Computational timings for a series of covalent-organic frameworks demonstrate that a speed-up of at least 1 order of magnitude can be achieved for excited-state geometry optimizations in comparison to conventional hybrid functionals. The second method is to use a semiempirical tight binding approximation for both Coulomb and exchange contributions to the excited-state kernel. This simplified Tamm-Dancoff approximation (sTDA) achieves an accuracy comparable to approximated hybrid density functional theory when referring to highly accurate coupled-cluster reference data. We find that excited-state bond lengths deviate by 1.1 pm on average and mean absolute errors in vertical excitation, adiabatic excitation, and fluorescence energies are in the range of 0.2-0.5 eV. In comparison to ADMM-approximated hybrid functional theory, sTDA accelerates the computation of broad-band excitation spectra by 1 order of magnitude, suggesting its potential use for large-scale screening purposes.

7.
Glob Transit ; 3: 99-108, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34870136

RESUMO

The demand of online remote working from home significantly increased in 2020/21 due to the Covid-19 pandemic. This unforeseen situation has forced individuals and organisations to rapidly train employees and adopt the use of on-line working styles, seeking to maintain the same level of productivity as working from the office. The paper outlines a survey conducted amongst people working from home to identify the challenges and opportunities this change in workstyle offers. At the beginning of the pandemic, many employees faced difficulties adapting to using online tools and combining their working hours with daily routines and family commitments. However, the results show that within a short period of time the respondents had managed to develop the necessary experience and knowledge for digital working utilising tools such as collaboration platforms and video conferencing. A large proportion of respondents recognised the advantage of eliminating travelling time when working remotely from home which also has a positive impact on the environment and CO2 emissions. However, some drawbacks have been identified such as the lack of face-to-face discussion and informal meetings during working days. The Self-Determination Theory is discussed within the context of this paper and it has been found that the theory could provide an explanation of the efficient and rapid adaptation of the technology be employees.

8.
Int J Gynecol Pathol ; 40(3): 240-247, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32897964

RESUMO

Beta-catenin (BC) mutations are associated with a high risk of recurrence in otherwise low-grade, early-stage uterine endometrioid adenocarcinomas. Recent literature suggests nuclear BC expression by immunohistochemistry is highly sensitive and specific for BC mutations. The significance of BC expression in endometrioid intraepithelial neoplasia (EIN/atypical hyperplasia) and its relationship to altered differentiation patterns in EIN has yet to be fully explored. Cases meeting current diagnostic criteria for EIN based on H&E examination were obtained from 2 institutions (years 1999-2014). Patterns of altered differentiation (eg, tubal, squamous morular metaplasia, mucinous, secretory) were noted. Representative blocks were stained for BC, and expression patterns recorded. Follow-up and demographic data was obtained from the electronic medical record. Ninety-six cases were included (84 biopsies, 12 hysterectomies). BC nuclear expression was identified in 41 cases (42.7%), with 33 of 41 demonstrating foci of nonmorular BC staining. BC staining in any component of EIN was not significantly associated with the presence of carcinoma on subsequent hysterectomy (P=0.79). When restricting to nonmorular BC, the results were the same (P=0.56). Cases with tubal differentiation were significantly less likely to demonstrate nonmorular BC than cases with no specific pattern of differentiation (P<0.01). EIN frequently demonstrates BC nuclear positivity, especially in cases without tubal differentiation. BC nuclear expression in EIN does not appear to be associated with an increased likelihood of carcinoma on subsequent hysterectomy. Our results do not support routine use of BC immunohistochemistry as a prognostic biomarker in cases of EIN.


Assuntos
Carcinoma in Situ/diagnóstico , Carcinoma Endometrioide/diagnóstico , Neoplasias do Endométrio/diagnóstico , beta Catenina/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/metabolismo , Carcinoma in Situ/patologia , Carcinoma in Situ/cirurgia , Carcinoma Endometrioide/patologia , Carcinoma Endometrioide/cirurgia , Núcleo Celular/metabolismo , Neoplasias do Endométrio/patologia , Neoplasias do Endométrio/cirurgia , Feminino , Humanos , Histerectomia , Pessoa de Meia-Idade , Prognóstico , Risco , beta Catenina/genética
9.
Nat Food ; 2(9): 655-663, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37117479

RESUMO

The recent development of true cost accounting (TCA) methodologies by various organizations has helped increase transparency in the food sector, but has also made it difficult to compare the results obtained through different methodologies. Here we review major TCA methodologies across five functional units that their assessment framework(s) apply to-namely product, organization, system, geography and investment. Our results show that the bulk of existing frameworks apply to products and/or organizations. According to publicly available documents and case studies published by the framework proponents, we found measurements of externality/dependency, the inclusion of economic, environmental and social effects, as well as the use of comparable metrics to be areas of general consensus; suggested indicators, monetization and aggregation emerged as areas of general divergence. The differences between TCA methodologies identified in this study indicate that collaboration between frameworks is key to their harmonization, ultimately making results more comparable and facilitating engagement in TCA.

10.
Eur J Vasc Endovasc Surg ; 59(6): 957-964, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32336621

RESUMO

OBJECTIVE: The aims of this study were firstly to assess the correlation between disease specific measures of quality of life (QOL) and physical performance and activity, and secondly to identify demographic, clinical, functional, and physical activity measures independently associated with QOL in people with intermittent claudication. METHODS: This was a cross sectional observational study of 198 people with intermittent claudication caused by peripheral artery disease who were recruited prospectively. QOL was assessed with the intermittent claudication questionnaire (ICQ) and the eight-theme peripheral artery disease quality of life questionnaire. Physical performance was assessed with the six minute walk test (6MWT) and short physical performance battery (SPPB), and an accelerometer was used to measure seven day step count. The associations between QOL scores and 6MWT distance, SPPB scores and seven day step count were examined using Spearman Rho's (ρ) correlation and multivariable linear regression. RESULTS: ICQ scores were significantly correlated with 6MWT distance (ρ = 0.472, p < .001), all four SPPB scores (balance ρ = 0.207, p = .003; gait speed ρ = 0.303, p < .001; chair stand ρ = 0.167, p = .018; total ρ = 0.265, p < .001), and seven day step count (ρ = 0.254, p < .001). PADQOL social relationships and interactions (ρ = 0.343, p < .001) and symptoms and limitations in physical functioning (ρ = 0.355, p < .001) themes were correlated with 6MWT distance. The 6MWT distance was independently positively associated with ICQ and both PADQOL theme scores (ICQ: B 0.069, p < .001; PADQOL social relationships and interactions: B 0.077, p < .001; PADQOL symptoms and limitations in physical functioning: B 0.069, p < .001). CONCLUSION: Longer 6MWT distance independently predicted better physical and social aspects of QOL in people with intermittent claudication supporting its value as an outcome measure.


Assuntos
Claudicação Intermitente/diagnóstico , Medidas de Resultados Relatados pelo Paciente , Doença Arterial Periférica/complicações , Desempenho Físico Funcional , Qualidade de Vida , Idoso , Estudos Transversais , Feminino , Humanos , Claudicação Intermitente/etiologia , Claudicação Intermitente/fisiopatologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Teste de Caminhada
11.
Front Chem ; 7: 210, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31024896

RESUMO

We report a combined non-local (PBE-TC-LRC) Density Functional Theory (DFT) and linear-response time-dependent DFT (LR-TDDFT) study of the structural, electronic, and optical properties of the cation-vacancy based defects in aluminosilicate (AlSi) imogolite nanotubes (Imo-NTs) that have been recently proposed on the basis of Nuclear Magnetic Resonance (NMR) experiments. Following numerical determination of the smallest AlSi Imo-NT model capable of accommodating the defect-induced relaxation with negligible finite-size errors, we analyse the defect-induced structural deformations in the NTs and ensuing changes in the NTs' electronic structure. The NMR-derived defects are found to introduce both shallow and deep occupied states in the pristine NTs' band gap (BG). These BG states are found to be highly localized at the defect site. No empty defect-state is modeled for any of the considered systems. LR-TDDFT simulation of the defects reveal increased low-energy optical absorbance for all but one defects, with the appearance of optically active excitations at energies lower than for the defect-free NT. These results enable interpretation of the low-energy tail in the experimental UV-vis spectra for AlSi NTs as being due to the defects. Finally, the PBE-TC-LRC-approximated exciton binding energy for the defects' optical transitions is found to be substantially lower (up to 0.8 eV) than for the pristine defect-free NT's excitations (1.1 eV).

12.
J Chem Phys ; 150(4): 044702, 2019 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-30709253

RESUMO

Using an advanced computational methodology implemented in CP2K, a non-local PBE0-TC-LRC density functional and the recently implemented linear response formulation of the Time-dependent Density Functional Theory equations, we test the interpretation of the optical absorption and photoluminescence signatures attributed by previous experimental and theoretical studies to O-vacancies in two widely used oxides-cubic MgO and monoclinic (m)-HfO2. The results obtained in large periodic cells including up to 1000 atoms emphasize the importance of accurate predictions of defect-induced lattice distortions. They confirm that optical transitions of O-vacancies in 0, +1, and +2 charge states in MgO all have energies close to 5 eV. We test the models of photoluminescence of O-vacancies proposed in the literature. The photoluminescence of VO +2 centers in m-HfO2 is predicted to peak at 3.7 eV and originate from radiative tunneling transition between a VO +1 center and a self-trapped hole created by the 5.2 eV excitation.

13.
Nat Chem ; 10(11): 1112-1117, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30150724

RESUMO

On-surface polymerization is a promising technique to prepare organic functional nanomaterials that are challenging to synthesize in solution, but it is typically used on metal substrates, which play a catalytic role. Previous examples on insulating surfaces have involved intermediate self-assembled structures, which face high barriers to diffusion, or annealing to higher temperatures, which generally causes rapid dewetting and desorption of the monomers. Here we report the photoinitiated radical polymerization, initiated from a two-dimensional gas phase, of a dimaleimide monomer on an insulating KCl surface. Polymer fibres up to 1 µm long are formed through chain-like rather than step-like growth. Interactions between potassium cations and the dimaleimide's oxygen atoms facilitate the propagation of the polymer fibres along a preferred axis of the substrate over long distances. Density functional theory calculations, non-contact atomic force microscopy imaging and manipulations at room temperature were used to explore the initiation and propagation processes, as well as the structure and stability of the resulting one-dimensional polymer fibres.

14.
Am Heart J ; 201: 111-116, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29763816

RESUMO

The prognosis of patients with HFrEF remains poor despite the use of current medical and device therapies. Preclinical studies of HFrEF using IC delivery of RT-100, a replication deficient, E1/E3-deleted human adenovirus 5 encoding human AC6 was associated with favorable effects on LV function and remodeling. A recent multicenter, double-blind, placebo-controlled, phase 2 study demonstrated the safety of IC delivery of RT-100 in HFrEF patients and potential efficacy at the higher doses. This phase 2 dose finding study, which included doses not expected to be effective, identified a potential reduction in congestive heart failure admissions in the AC6-treated group one year after randomization. The FLOURISH study is designed to investigate the prospect of reduction of heart failure hospitalization and other clinical adverse events and improvement in EF. The FLOURISH study is a double-blind, placebo-controlled, multicenter Phase 3 clinical trial that will randomize 536 patients to a one-time IC administration of RT-100 (1012 vp) or placebo in a 1:1 ratio. Subjects will be 18-80 years of age, on optimal standard of care HF therapy with LVEF ≥10% and ≤35% by echocardiogram, and will undergo IC administration of RT-100 vs. placebo on Day 1. Follow-up study visits will be performed at Weeks 1 and 4, and Months 3, 6, and 12. Patients will be followed for an additional 36 months for safety assessments with telephone contact at Months 24, 36, and 48. The primary objective is to determine the efficacy of IC RT-100 vs. placebo in reducing the event rate of all (first and repeat) HF hospitalizations occurring from baseline to 12 months. The secondary objectives are to determine the efficacy of IC RT-100 on CV death, all cause death, and all HF events and in improving NYHA functional classification. Exploratory endpoints will include echocardiographic parameters of left ventricular systolic and diastolic function, HF symptoms and physical limitations, 6-minute walking distance, Borg dyspnea score, and NT-proBNP levels. The FLOURISH study, which received fast track designation from the Food and Drug Administration in December 2017, will further investigate the role of a one-time intracoronary injection of RT-100 in reducing HF hospitalizations and will serve as a registration trial (potentially pivotal investigation) for RT-100 as a treatment for HFrEF.


Assuntos
Adenilil Ciclases/administração & dosagem , Ensaios Clínicos Fase III como Assunto/métodos , Técnicas de Transferência de Genes , Terapia Genética/métodos , Insuficiência Cardíaca/terapia , Ensaios Clínicos Controlados Aleatórios como Assunto/métodos , Volume Sistólico/fisiologia , Adenovírus Humanos , Vasos Coronários , Insuficiência Cardíaca/fisiopatologia , Humanos , Injeções Intra-Arteriais , Função Ventricular Esquerda/fisiologia
15.
JAMA Cardiol ; 1(2): 163-71, 2016 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-27437887

RESUMO

IMPORTANCE: Gene transfer has rarely been tested in randomized clinical trials. OBJECTIVE: To evaluate the safety and efficacy of intracoronary delivery of adenovirus 5 encoding adenylyl cyclase 6 (Ad5.hAC6) in heart failure. DESIGN, SETTING, AND PARTICIPANTS: A randomized, double-blind, placebo-controlled, phase 2 clinical trial was conducted in US medical centers (randomization occurred from July 19, 2010, to October 30, 2014). Participants 18 to 80 years with symptomatic heart failure (ischemic and nonischemic) and an ejection fraction (EF) of 40% or less were screened; 86 individuals were enrolled, and 56 were randomized. Data analysis was of the intention-to-treat population. Participants underwent exercise testing and measurement of left ventricular EF (echocardiography) and then cardiac catheterization, where left ventricular pressure development (+dP/dt) and decline (-dP/dt) were recorded. Participants were randomized (3:1 ratio) to receive 1 of 5 doses of intracoronary Ad5.hAC6 or placebo. Participants underwent a second catheterization 4 weeks later for measurement of dP/dt. Exercise testing and EF were assessed 4 and 12 weeks after randomization. INTERVENTIONS: Intracoronary administration of Ad5.hAC6 (3.2 × 109 to 1012 virus particles) or placebo. MAIN OUTCOMES AND MEASURES: Primary end points included exercise duration and EF before and 4 and 12 weeks after randomization and peak rates of +dP/dt and -dP/dt before and 4 weeks after randomization. Fourteen placebo participants were compared (intention to treat) with 24 Ad5.hAC6 participants receiving the highest 2 doses (D4 + 5). RESULTS: Fifty-six individuals were randomized and monitored for up to 1 year. Forty-two participants (75%) received Ad5.hAC6 (mean [SE] age, 63 [1] years; EF, 30% [1%]), and 14 individuals (25%) received placebo (age, 62 [1] years; EF, 30% [2%]). Exercise duration showed no significant group differences (4 weeks, P = .27; 12 weeks, P = .47, respectively). The D4 + 5 participants had increased EF at 4 weeks (+6.0 [1.7] EF units; n = 21; P < .004), but not 12 weeks (+3.0 [2.4] EF units; n = 21; P = .16). Placebo participants showed no increase in EF at 4 weeks or 12 weeks. Exercise duration showed no between-group differences (4-week change from baseline: placebo, 27 [36] seconds; D4 + 5, 44 [25] seconds; P = .27; 12-week change from baseline: placebo, 44 [28] seconds; D4 + 5, 58 [29 seconds, P = .47). AC6 gene transfer increased basal left ventricular peak -dP/dt (4-week change from baseline: placebo, +93 [51] mm Hg/s; D4 + 5, -39 [33] mm Hg/s; placebo [n = 21]; P < .03); AC6 did not increase arrhythmias. The admission rate for patients with heart failure was 9.5% (4 of 42) in the AC6 group and 28.6% (4 of 14) in the placebo group (relative risk, 0.33 [95% CI, 0.08-1.36]; P = .10). CONCLUSIONS AND RELEVANCE: AC6 gene transfer safely increased LV function beyond standard heart failure therapy, attainable with one-time administration. Larger trials are warranted. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00787059.


Assuntos
Adenoviridae/genética , Adenilil Ciclases/administração & dosagem , Técnicas de Transferência de Genes/tendências , Terapia Genética/métodos , Insuficiência Cardíaca/diagnóstico , Volume Sistólico/efeitos dos fármacos , Função Ventricular Esquerda/efeitos dos fármacos , Adenilil Ciclases/uso terapêutico , Idoso , Cateterismo Cardíaco/métodos , Ecocardiografia , Teste de Esforço/métodos , Feminino , Insuficiência Cardíaca/diagnóstico por imagem , Insuficiência Cardíaca/genética , Insuficiência Cardíaca/fisiopatologia , Insuficiência Cardíaca/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Admissão do Paciente/estatística & dados numéricos , Resultado do Tratamento , Estados Unidos/epidemiologia
16.
Nanoscale ; 8(13): 7334-42, 2016 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-26980273

RESUMO

Hydration plays important roles in various solid-liquid interfacial phenomena. Very recently, three-dimensional scanning force microscopy (3D-SFM) has been proposed as a tool to visualise solvated surfaces and their hydration structures with lateral and vertical (sub) molecular resolution. However, the relationship between the 3D force map obtained and the equilibrium water density, ρ(r), distribution above the surface remains an open question. Here, we investigate this relationship at an interface of an inorganic mineral, fluorite, and water. The force maps measured in pure water are directly compared to force maps generated using the solvent tip approximation (STA) model and from explicit molecular dynamics simulations. The results show that the simulated STA force map describes the major features of the experimentally obtained force image. The agreement between the STA data and the experiment establishes the correspondence between the water density used as an input to the STA model and the experimental hydration structure and thus provides a tool to bridge the experimental force data and atomistic solvation structures. Further applications of this method should improve the accuracy and reliability of both interpretation of 3D-SFM force maps and atomistic simulations in a wide range of solid-liquid interfacial phenomena.

17.
J Comput Chem ; 36(16): 1187-95, 2015 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-25891018

RESUMO

We present an efficient scheme for parametrizing complex molecule-surface force fields from ab initio data. The cost of producing a sufficient fitting library is mitigated using a 2D periodic embedded slab model made possible by the quantum mechanics/molecular mechanics scheme in CP2K. These results were then used in conjunction with genetic algorithm (GA) methods to optimize the large parameter sets needed to describe such systems. The derived potentials are able to well reproduce adsorption geometries and adsorption energies calculated using density functional theory. Finally, we discuss the challenges in creating a sufficient fitting library, determining whether or not the GA optimization has completed, and the transferability of such force fields to similar molecules.

18.
Phys Rev Lett ; 114(11): 115503, 2015 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-25839289

RESUMO

Using ab initio modeling we demonstrate that H atoms can break strained Si─O bonds in continuous amorphous silicon dioxide (a-SiO(2)) networks, resulting in a new defect consisting of a threefold-coordinated Si atom with an unpaired electron facing a hydroxyl group, adding to the density of dangling bond defects, such as E' centers. The energy barriers to form this defect from interstitial H atoms range between 0.5 and 1.3 eV. This discovery of unexpected reactivity of atomic hydrogen may have significant implications for our understanding of processes in silica glass and nanoscaled silica, e.g., in porous low-permittivity insulators, and strained variants of a-SiO(2).

19.
Cardiovasc Revasc Med ; 16(2): 65-9, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25576273

RESUMO

BACKGROUND/PURPOSE: Bare metal stents (BMS) have similar rates of death and myocardial infarction (MI) compared to drug-eluting stents (DES). DES lower repeat revascularization rates compared to BMS, but may have higher rates of late stent thrombosis (ST) potentially due to impaired endothelialization requiring longer dual anti-platelet therapy (DAPT). OMEGA evaluated a novel BMS designed to have improved deliverability and radiopacity, in comparison to currently available platforms. METHODS/MATERIALS: OMEGA was a prospective, multicenter, single-arm study enrolling 328 patients at 37 sites (US and Europe). Patients received the OMEGA stent (bare platinum chromium element stent) for the treatment of de novo native coronary artery lesions (≤28 mm long; diameter ≥2.25 mm to ≤4.50mm). The primary endpoint was 9-month target lesion failure (TLF: cardiac death, target vessel-related MI, target lesion revascularization [TLR]) compared to a prespecified performance goal (PG) based on prior generation BMS. All major cardiac events were independently adjudicated. DAPT was required for a minimum of 1 month post procedure. RESULTS: In the OMEGA study, the mean age was 65; 17% had diabetes mellitus. The primary endpoint was met; 9 month TLF rate was 11.5%, and the upper 1-sided 95% confidence bound of 14.79% was less than the prespecified PG of 21.2% (p<0.0001). One-year event rates were low including a TLF rate of 12.8% and an ST rate of 0.6% at 12 months. CONCLUSIONS: One-year outcomes of OMEGA show low rates of TLF, revascularization and ST. This supports safety and efficacy of the OMEGA BMS for the treatment of coronary artery disease.


Assuntos
Angioplastia Coronária com Balão/instrumentação , Estenose Coronária/terapia , Metais/uso terapêutico , Segurança do Paciente/estatística & dados numéricos , Stents , Idoso , Idoso de 80 Anos ou mais , Angioplastia Coronária com Balão/métodos , Angioplastia Coronária com Balão/mortalidade , Cromo/uso terapêutico , Angiografia Coronária/métodos , Reestenose Coronária/diagnóstico por imagem , Reestenose Coronária/mortalidade , Estenose Coronária/diagnóstico por imagem , Estenose Coronária/mortalidade , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Platina/uso terapêutico , Estudos Prospectivos , Desenho de Prótese , Medição de Risco , Índice de Gravidade de Doença , Método Simples-Cego , Taxa de Sobrevida , Fatores de Tempo , Resultado do Tratamento
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