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1.
ACS Appl Mater Interfaces ; 16(14): 17766-17777, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38534058

RESUMO

Serving as neuromorphic hardware accelerators, memristors play a crucial role in large-scale neuromorphic computing. Herein, two-terminal memristors utilizing amorphous indium-gallium-zinc oxide (a-IGZO) are fabricated through room-temperature sputtering. The electrical characteristics of these memristors are effectively modulated by varying the oxygen flow during the deposition process. The optimized a-IGZO memristor, fabricated under 3 sccm oxygen flow, presents a 5 × 103 ratio between its high- and low-resistance states, which can be maintained over 1 × 104 s with minimal degradation. Meanwhile, desirable properties such as electroforming-free and self-compliance, crucial for low-energy consumption, are also obtained in the a-IGZO memristor. Moreover, analog conductance switching is observed, demonstrating an interface-type behavior, as evidenced by its device-size-dependent performance. The coexistence of negative differential resistance with analog switching is attributed to the migration of oxygen vacancies and the trapping/detrapping of charges. Furthermore, the device demonstrates optical storage capabilities by exploiting the optical properties of a-IGZO, which can stably operate for up to 50 sweep cycles. Various synaptic functions have been demonstrated, including paired-pulse facilitation and spike-timing-dependent plasticity. These functionalities contribute to a simulated recognition accuracy of 90% for handwritten digits. Importantly, a one-selector one-memristor (1S1M) architecture is successfully constructed at room temperature by integrating a-IGZO memristor on a TaOx-based selector. This architecture exhibits a 107 on/off ratio, demonstrating its potential to suppress sneak currents among adjacent units in a memristor crossbar.

2.
PLoS One ; 18(10): e0292667, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37871102

RESUMO

OBJECTIVE: To determine the diagnostic accuracy of end-tidal carbon dioxide (ETCO2) detection using capnography for verifying the correct placement of nasogastric tubes (NGTs) among adult patients in hospital settings. MATERIALS AND METHODS: A prospective observational diagnostic study will be conducted. Patients ≥ 18-year-old and requiring the insertion of an NGT will be recruited using a convenience sampling method from 39 general medical and geriatric wards, intensive care units, accident and emergency departments, and subacute/rehabilitation/infirmary wards in 21 acute or subacute/convalescent/extended care hospitals. ETCO2 detection by sidestream capnography, which indicates an airway intubation of an NGT when a capnogram waveform or an ETCO2 level > 10mmHg (1.33 kPa) occurs, will serve as the index test. The reference standards will be the X-ray performed and pH value of gastric aspiration (pH ≤ 5.5) after the index test. Each participant will be included only once. Sensitivity, specificity, positive predictive value, negative predictive value, and area under the receiver operating characteristic curve of capnography will be calculated to assess the diagnostic performance of capnography. The variability in diagnostic accuracy in participants with different characteristics will be explored by using chi-squared or Fisher's exact tests. The time spent and the cost of the tests will be compared using the paired t-test. All statistical tests will be two-sided with a level of significance set at 0.05. DISCUSSION: This study will provide evidence on the diagnostic accuracy of capnography in verifying NGT placement and its applicability to patients in hospitals settings, since this evidence is limited in the current literature. In addition, it will help identify the optimal combination of tests in verifying the correct placement of NGTs and inform the update of clinical practice guidelines and stakeholders' decisions on the adoption of ETCO2 detection as a routine method for verifying NGT placement. TRIAL REGISTRATION: ClinicalTrials.gov ID: NCT05817864.


Assuntos
Capnografia , Dióxido de Carbono , Humanos , Adulto , Idoso , Adolescente , Capnografia/métodos , Intubação Gastrointestinal/métodos , Hospitais , Unidades de Terapia Intensiva , Estudos Observacionais como Assunto
3.
Crit Care ; 27(1): 399, 2023 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-37853490

RESUMO

BACKGROUND: Based on low-quality evidence, current nutrition guidelines recommend the delivery of high-dose protein in critically ill patients. The EFFORT Protein trial showed that higher protein dose is not associated with improved outcomes, whereas the effects in critically ill patients who developed acute kidney injury (AKI) need further evaluation. The overall aim is to evaluate the effects of high-dose protein in critically ill patients who developed different stages of AKI. METHODS: In this post hoc analysis of the EFFORT Protein trial, we investigated the effect of high versus usual protein dose (≥ 2.2 vs. ≤ 1.2 g/kg body weight/day) on time-to-discharge alive from the hospital (TTDA) and 60-day mortality and in different subgroups in critically ill patients with AKI as defined by the Kidney Disease Improving Global Outcomes (KDIGO) criteria within 7 days of ICU admission. The associations of protein dose with incidence and duration of kidney replacement therapy (KRT) were also investigated. RESULTS: Of the 1329 randomized patients, 312 developed AKI and were included in this analysis (163 in the high and 149 in the usual protein dose group). High protein was associated with a slower time-to-discharge alive from the hospital (TTDA) (hazard ratio 0.5, 95% CI 0.4-0.8) and higher 60-day mortality (relative risk 1.4 (95% CI 1.1-1.8). Effect modification was not statistically significant for any subgroup, and no subgroups suggested a beneficial effect of higher protein, although the harmful effect of higher protein target appeared to disappear in patients who received kidney replacement therapy (KRT). Protein dose was not significantly associated with the incidence of AKI and KRT or duration of KRT. CONCLUSIONS: In critically ill patients with AKI, high protein may be associated with worse outcomes in all AKI stages. Recommendation of higher protein dosing in AKI patients should be carefully re-evaluated to avoid potential harmful effects especially in patients who were not treated with KRT. TRIAL REGISTRATION: This study is registered at ClinicalTrials.gov (NCT03160547) on May 17th 2017.


Assuntos
Injúria Renal Aguda , Estado Terminal , Humanos , Injúria Renal Aguda/terapia , Estado Terminal/terapia , Estado Terminal/epidemiologia , Hospitalização , Unidades de Terapia Intensiva , Tempo de Internação , Terapia de Substituição Renal
4.
Intensive Crit Care Nurs ; 79: 103498, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37562998

RESUMO

OBJECTIVES: To pool the overall prevalence of delirium among critically ill patients who received extracorporeal membrane oxygenation (ECMO) support. METHODOLOGY: This systematic review and proportional meta-analysis was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Meta-analysis of Observational Studies in Epidemiology (MOOSE) reporting guidelines. Six electronic databases including PubMed, Cochrane Library, Web of Science, EMBASE, CINAHL, and PsycINFO were searched from inception to March 2023. The Newcastle-Ottawa Scale was used to assess the methodological quality of the included studies. A random effects model was used to pool the summary prevalence estimates and 95% CIs using the score statistic and the exact binomial method and incorporates the Freeman-Tukey double arcsine transformation of proportions. Sensitivity analyses including subgroup analysis, meta-regression, and outlier detection were carried out. SETTING: Intensive care units. MAIN OUTCOME MEASURES: Prevalence of delirium. RESULTS: A total of 10 studies involving 8,580 patients were included for meta-analysis. All studies had a low risk of bias in methodological quality. The pooled prevalence rate of 40.79% [95% CI, 17.58%-66.25%] was observed. The between-study heterogeneity (I2) was 98.28%. The subgroup analysis reveals the pooled prevalence of delirium for veno-arterial (V-A) ECMO, veno-venous (V-V) ECMO, and mixed sample of V-A and V-V ECMO were 63.57% [95% CI, 55.77%-71.04%], 51.84% [95% CI, 37.43%-66.12%] and 35.23% [95% CI, 11.84%-62.95%], respectively. Sample size (p = 0.024) was a significant factor associated with the heterogeneity. No evidence for small-study effects was observed (Egger's test: p = 0.5664). CONCLUSION: This systematic review and proportional meta-analysis reveals a high prevalence of delirium among critically ill patients who received ECMO support. IMPLICATIONS FOR CLINICAL PRACTICE: The results of this meta-analysis can be epidemiological evidence to inform the awareness of clinicians and researchers in critical care clinical practice and research.


Assuntos
Delírio , Oxigenação por Membrana Extracorpórea , Humanos , Oxigenação por Membrana Extracorpórea/efeitos adversos , Oxigenação por Membrana Extracorpórea/métodos , Estado Terminal/epidemiologia , Estado Terminal/terapia , Prevalência , Unidades de Terapia Intensiva , Delírio/epidemiologia , Delírio/etiologia , Estudos Observacionais como Assunto
5.
Artif Organs ; 47(6): 1046-1058, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37012220

RESUMO

BACKGROUND: Various strategies of weaning V-A ECMO have been described. PCRTO is a weaning technique which involves serial decremental pump revolutions until a retrograde flow from the arterial to venous ECMO cannula is achieved. It has been reported as a feasible weaning strategy in the pediatric population, but its application in adults has not been widely reported. METHODS: This was a case series including all adult patients who underwent PCRTO during weaning from V-A ECMO at a tertiary ECMO center between January 2019 and July 2021. The primary end point was the successful weaning from V-A ECMO support. RESULTS: A total of 57 runs of PCRTO in 36 patients were analyzed-45 (78.9%) of the trials were concluded successfully. The median retrograde blood flow rate during PCRTO was 0.6 ± 0.2 L/min, and the median duration of each PCRTO was 180 (120-240) min. Of the 35 patients who had at least one session of successful PCRTO, 31 (88.6%) were ultimately weaned from ECMO. There were no major complications from PCRTO including systemic or circuit thrombosis. CONCLUSIONS: PCRTO is a feasible strategy for assessing readiness for weaning from V-A ECMO with a low risk of adverse events and high rate of predicting eventual successful ECMO decannulation. Further investigation including comparison with alternative weaning strategies in prospective studies is required to confirm the approach.


Assuntos
Oxigenação por Membrana Extracorpórea , Humanos , Adulto , Criança , Oxigenação por Membrana Extracorpórea/efeitos adversos , Oxigenação por Membrana Extracorpórea/métodos , Estudos de Viabilidade , Artérias , Estudos Prospectivos , Cateterismo , Estudos Retrospectivos
6.
Cureus ; 13(9): e17796, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34660006

RESUMO

Anemia is a diagnostic challenge in patients with coronavirus disease 2019 (COVID-19). This is due to the broad differential of etiologies for anemia, which includes bleeding, bone marrow suppression secondary to sepsis, and hemolytic anemia. Here, we present a first-ever case of otherwise unexplained anemia in a patient receiving treatment for COVID-19 secondary to parvovirus B19 reactivation. While parvovirus infections often present as acute states of anemia, this patient developed a case of reactivation secondary to immunosuppression from COVID-19 treatment. This case indicates the importance of assessing for parvovirus infections in COVID-19 patients with otherwise unexplained anemia.

7.
J Acoust Soc Am ; 150(1): 321, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34340495

RESUMO

This paper presents a semi-analytical method of suppressing acoustic scattering using reinforcement learning (RL) algorithms. We give a RL agent control over design parameters of a planar configuration of cylindrical scatterers in water. These design parameters control the position and radius of the scatterers. As these cylinders encounter an incident acoustic wave, the scattering pattern is described by a function called total scattering cross section (TSCS). Through evaluating the gradients of TSCS and other information about the state of the configuration, the RL agent perturbatively adjusts design parameters, considering multiple scattering between the scatterers. As each adjustment is made, the RL agent receives a reward negatively proportional to the root mean square of the TSCS across a range of wavenumbers. Through maximizing its reward per episode, the agent discovers designs with low scattering. Specifically, the double deep Q-learning network and the deep deterministic policy gradient algorithms are employed in our models. Designs discovered by the RL algorithms performed well when compared to a state-of-the-art optimization algorithm using fmincon.

8.
J Acoust Soc Am ; 150(6): 4362, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34972305

RESUMO

This work presents a method for the reduction of the total scattering cross section (TSCS) for a planar configuration of cylinders by means of generative modeling and deep learning. Currently, the minimization of TSCS requires repeated forward modelling at considerable computer resources, whereas deep learning can do this more efficiently. The conditional Wasserstein generative adversarial networks (cWGANs) model is proposed for minimization of TSCS in two dimensions by combining Wasserstein generative adversarial networks with convolutional neural networks to simulate TSCS of configuration of rigid scatterers. The proposed cWGAN model is enhanced by adding to it a coordinate convolution (CoordConv) layer. For a given number of cylinders, the cWGAN model generates images of 2D configurations of cylinders that minimize the TSCS. The proposed generative model is illustrated with examples for planar uniform configurations of rigid cylinders.

9.
Crit Care Med ; 48(3): 406-414, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31833901

RESUMO

OBJECTIVES: The purpose of this position paper is two-fold: first, to describe the state of extracorporeal membrane oxygenation education worldwide, noting current limitations and challenges; and second, to put forth an educational agenda regarding opportunities for an international collaborative approach toward standardization. DESIGN: Relevant medical literature was reviewed through literature search, and materials from national organizations were accessed through the Internet. Taskforce members generated a consensus statement using an iterative consensus process through teleconferences and electronic communication. SETTING: In 2018, the Extracorporeal Life Support Organization convened the ECMOed Taskforce at two structured, face-to-face meetings of 40 healthcare practitioners and educators with expertise in caring for the extracorporeal membrane oxygenation patient and in extracorporeal membrane oxygenation education. PATIENTS: None. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The ECMOed Taskforce identified seven educational domains that would benefit from international collaborative efforts. Of primary importance, the Taskforce outlined actionable items regarding 1) the creation of a standardized extracorporeal membrane oxygenation curriculum; 2) defining criteria for an extracorporeal membrane oxygenation course as a vehicle for delivering the curriculum; 3) outlining a mechanism for evaluating the quality of educational offerings; 4) utilizing validated assessment tools in the development of extracorporeal membrane oxygenation practitioner certification; and 5) promoting high-quality educational research to guide ongoing educational and competency assessment development. CONCLUSIONS: Significant variability and limitations in global extracorporeal membrane oxygenation education exist. In this position paper, we outline a road map for standardizing international extracorporeal membrane oxygenation education and practitioner certification. Ongoing high-quality educational research is needed to evaluate the impact of these initiatives.


Assuntos
Oxigenação por Membrana Extracorpórea/educação , Oxigenação por Membrana Extracorpórea/normas , Internacionalidade , Certificação/normas , Comportamento Cooperativo , Currículo , Humanos , Avaliação de Processos em Cuidados de Saúde , Estudos Retrospectivos
10.
J Thorac Dis ; 11(5): 2144-2152, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31285909

RESUMO

Extracorporeal membrane oxygenation (ECMO) education, in particular with regards to crisis management during the provision of venoarterial extracorporeal membrane oxygenation (VA ECMO), is challenging due to its intrinsic characteristics-a complex, high risk, low volume clinical activity which requires dynamic decision making, interdisciplinary teamwork and communication, and rapid response. Simulation training that focuses on crisis resource management and interprofessional communication is well-suited to address these training needs. Institutional commitment to provide both capital and human resources is instrumental to the success of ECMO training programs. Future multicenter studies with standardized training curricula are required to investigate the impact of ECMO simulation training on patient outcome.

11.
Crit Care Nurs Q ; 42(1): 117-126, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30507672

RESUMO

Pressure injury is a serious problem and is common in critical care units. Over the last decade, there is new evidence suggesting that the use of multilayered silicone foam dressing as preventive measures can decrease the incidence and prevalence rate of hospital-acquired pressure injury. The purpose of this study was to investigate the clinical efficacy of this dressing in reducing sacral and coccygeal pressure injury incidence rate as compared with standard preventive interventions in critical care settings.


Assuntos
Bandagens , Úlcera por Pressão/prevenção & controle , Silicones/uso terapêutico , Idoso , Feminino , Hong Kong/epidemiologia , Hospitais Universitários , Humanos , Unidades de Terapia Intensiva , Masculino , Pessoa de Meia-Idade , Úlcera por Pressão/epidemiologia , Região Sacrococcígea
12.
Curr Pharm Teach Learn ; 9(2): 272-281, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29233413

RESUMO

PURPOSE: To assess the impact of coordinated didactic, simulation-based, and experiential learning on pharmacy students' knowledge and confidence with Medicare Part D and their accuracy and proficiency with the Medicare Plan Finder Tool. EDUCATIONAL ACTIVITY: Forty-two pharmacy students participated in a two-semester Medicare Part D elective course in which didactic, simulation-based and experiential learning methods were employed. Students' knowledge, confidence, accuracy, and proficiency were assessed at three course time points: first day of class, last day of in-class education, and after completion of outreach. FINDINGS: Student confidence with Part D and efficiency using the Plan Finder Tool significantly improved at each successive time point (p<0.01). Student knowledge was significantly improved both on the last day of class and after outreach completion as compared to the first day of class (p<0.01). SUMMARY: Basic Part D knowledge improved with the didactic and simulation-based portion of the course. The experiential component improved student confidence and efficiency in helping Medicare beneficiaries.


Assuntos
Educação em Farmácia/métodos , Medicare Part D/tendências , Administração Farmacêutica/normas , Estudantes de Farmácia , Currículo/normas , Currículo/tendências , Feminino , Humanos , Masculino , Estados Unidos , Adulto Jovem
13.
ACS Nano ; 10(10): 9183-9192, 2016 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-27571459

RESUMO

Cell size control and homeostasis are fundamental features of bacterial metabolism. Recent work suggests that cells add a constant size between birth and division ("adder" model). However, it is not known how cell size homeostasis is influenced by the existence of heterogeneous microenvironments, such as those during biofilm formation. Shewanella oneidensis MR-1 can use diverse energy sources on a range of surfaces via extracellular electron transport (EET), which can impact growth, metabolism, and size diversity. Here, we track bacterial surface communities at single-cell resolution to show that not only do bacterial motility appendages influence the transition from two- to three-dimensional biofilm growth and control postdivisional cell fates, they strongly impact cell size homeostasis. For every generation, we find that the average growth rate for cells that stay on the surface and continue to divide (nondetaching population) and that for cells that detach before their next division (detaching population) are roughly constant. However, the growth rate distribution is narrow for the nondetaching population, but broad for the detaching population in each generation. Interestingly, the appendage deletion mutants (ΔpilA, ΔmshA-D, Δflg) have significantly broader growth rate distributions than that of the wild type for both detaching and nondetaching populations, which suggests that Shewanella appendages are important for sensing and integrating environmental inputs that contribute to size homeostasis. Moreover, our results suggest multiplexing of appendages for sensing and motility functions contributes to cell size dysregulation. These results can potentially provide a framework for generating metabolic diversity in S. oneidensis populations to optimize EET in heterogeneous environments.

14.
JAMA Oncol ; 2(8): 1065-9, 2016 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-27227654

RESUMO

IMPORTANCE: The management of lymphoma diagnosed during pregnancy is controversial and has been guided largely by findings from case reports and small series. OBJECTIVE: To determine maternal and fetal outcomes of women diagnosed with Hodgkin lymphoma (HL) or non-Hodgkin lymphoma (NHL) during pregnancy. DESIGN, SETTING, AND PARTICIPANTS: This retrospective analysis studied a cohort of 39 pregnant women diagnosed with HL and NHL (31 HL and 8 NHL) at a single specialized cancer institution between January 1991 and December 2014. MAIN OUTCOMES AND MEASURES: We examined data on disease and treatment characteristics, as well as maternal and fetal complications and outcomes. The Kaplan-Meier method was used to compare progression free survival (PFS) and overall survival (OS) according to receipt of antenatal therapy and other clinical factors. Univariate and multivariate analyses were performed by using Cox proportional hazard regression models to identify potential associations between clinical and treatment factors and survival. RESULTS: The median (range) age of the 39 women in the patient cohort was 28 (19-38) years; 32 women (82%) had stage I or II disease at diagnosis, and 13 had bulky disease. Three women electively terminated the pregnancy to allow immediate systemic therapy; of the remaining 36 women, 24 received antenatal therapy (doxorubicin based combination chemotherapy in 20 of 24 patients), and 12 deferred therapy until after delivery. Four women experienced miscarriage, all of whom had received antenatal systemic therapy and 2 during the first trimester. Delivery occurred at a median (range) of 37 (32-42) weeks and was no different based on receipt of antenatal (median [range], 37 [33-42] weeks) vs postnatal (median [range], 37 [32-42] weeks) therapy (P = .21). No gross fetal malformations or anomalies were detected. At a median (range) follow-up time of 67.9 (8.8-277.5) months since the diagnosis of lymphoma, 5-year rates of PFS and OS were 74.7% and 82.4%, respectively; these rates did not differ according to timing of therapy. On univariate analysis, bulky disease (>10 cm), extranodal nonbone marrow involvement, and poor performance status (Eastern Cooperative Oncology Group score, ≥2) predicted increased risk of disease progression. On multivariate analysis, extranodal nonbone marrow disease and performance status remained significant for both PFS and OS. CONCLUSIONS AND RELEVANCE: Systemic therapy given for lymphoma after the first trimester of pregnancy is likely safe and results in acceptable maternal and fetal outcomes.


Assuntos
Aborto Espontâneo/epidemiologia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Anormalidades Congênitas/epidemiologia , Doença de Hodgkin/terapia , Linfoma não Hodgkin/terapia , Complicações Neoplásicas na Gravidez/terapia , Radioterapia , Aborto Induzido , Adulto , Estudos de Coortes , Gerenciamento Clínico , Intervalo Livre de Doença , Feminino , Doença de Hodgkin/diagnóstico por imagem , Doença de Hodgkin/patologia , Humanos , Estimativa de Kaplan-Meier , Linfoma não Hodgkin/diagnóstico por imagem , Linfoma não Hodgkin/patologia , Imageamento por Ressonância Magnética , Análise Multivariada , Estadiamento de Neoplasias , Período Pós-Parto , Gravidez , Complicações Neoplásicas na Gravidez/diagnóstico por imagem , Complicações Neoplásicas na Gravidez/patologia , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Resultado do Tratamento , Ultrassonografia , Adulto Jovem
15.
Nanoscale Res Lett ; 9(1): 597, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25404870

RESUMO

We have studied the capacitance effect on the oscillation characteristics and the switching characteristics of the spin torque oscillators (STOs). We found that when the external field is applied, the STO oscillation frequency exhibits various dependences on the capacitance for injected current ranging from 8 to 20 mA. The switching characteristic is featured with the emerging of the canted region; the canted region increases with the capacitance. When the external field is absent, the STO free-layer switching time exhibits different dependences on the capacitance for different injected current. These results help to establish the foundation for capacitance-involved STO modeling.

16.
Chem Senses ; 39(2): 107-23, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24398973

RESUMO

Using computational methods, which allow mechanistic insights at a molecular level, we explored the olfactory receptor (OR)-odor interactions for 2 mouse ORs, S79 and S86. Both ORs have been previously experimentally, functionally characterized. The odors used were mostly carboxylic acids, which differed in chain length, substituents on the primary carbon atom-chain and degree of unsaturation. These odors elicited varied activation responses from both ORs. Our studies revealed that both receptors have 2 distinct binding sites. Preferential binding in 1 of the 2 sites is correlated with OR activation. The activating odorants: nonanedioic acid, heptanoic acid, and octanoic acid for OR S79 and nonanoic acid for OR S86 preferentially bind in the region bound by transmembranes (TMs [helical domains]) III, IV, V, and VI. The non excitatory odorants heptanol for S79 and heptanoic acid for S86 showed a greater likelihood of binding in the region bound by TMs I, II, III, and VII. Nanosecond-scale molecular dynamics simulations of the physiologically relevant conditions of docked OR-odorant complexes enabled us to quantitatively assess the roles of individual OR amino acids in odor binding. Amino acid-odorant contact maps and distance determinations over the course of the simulations lend support to our conclusions.


Assuntos
Odorantes , Receptores Odorantes/fisiologia , Animais , Sítios de Ligação , Ligantes , Camundongos , Modelos Moleculares , Simulação de Dinâmica Molecular , Domínios e Motivos de Interação entre Proteínas , Receptores Odorantes/química , Receptores Odorantes/genética , Homologia Estrutural de Proteína
17.
Nanotechnology ; 24(49): 495501, 2013 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-24231755

RESUMO

Nanorod forms of metal oxides are recognized as one of the most remarkable morphologies. Their structure and functionality have driven important advancements in a vast range of electronic devices and applications. In this work, we postulate a novel concept to explain how numerous localized surface states can be engineered into the bandgap of niobium oxide nanorods using tungsten. We discuss their contributions as local state surface charges for the modulation of a Schottky barrier height, the relative dielectric constant and their respective conduction mechanisms. Their effects on hydrogen gas molecule interaction mechanisms are also examined herein. We synthesized niobium tungsten oxide (Nb17W2O25) nanorods via a hydrothermal growth method and evaluated the Schottky barrier height, ideality factor, dielectric constant and trap energy level from the measured I-V versus temperature characteristics in the presence of air and hydrogen to show the validity of our postulations.

18.
Methods Mol Biol ; 1003: 3-22, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23585030

RESUMO

We present here, the salient aspects of three databases: Olfactory Receptor Database (ORDB) is a repository of genomics and proteomics information of ORs; OdorDB stores information related to odorous compounds, specifically identifying those that have been shown to interact with olfactory rectors; and OdorModelDB disseminates information related to computational models of olfactory receptors (ORs). The data stored among these databases is integrated. Presented in this chapter are descriptions of these resources, which are part of the SenseLab suite of databases, a discussion of the computational infrastructure that enhances the efficacy of information storage, retrieval, dissemination, and automated data population from external sources.


Assuntos
Bases de Dados de Proteínas , Proteômica/métodos , Receptores Odorantes/genética , Receptores Odorantes/metabolismo , Animais , Mineração de Dados , Humanos , Ratos , Receptores Odorantes/química
19.
Methods Mol Biol ; 1003: 53-65, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23585033

RESUMO

Providing a rationale that associates a chemical structure of an odorant to its induced perception has been sought for a long time. To achieve this, a detailed atomic structure of both the odorant and the olfactory receptor must be known. State-of-the-art techniques to model the 3D structure of an olfactory receptor in complex with various odorants are presented here. These range from sequence alignment with known structures to molecular dynamics simulations in a realistic environment.


Assuntos
Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Odorantes , Receptores Odorantes/química , Receptores Odorantes/metabolismo , Sequência de Aminoácidos , Membrana Celular/química , Membrana Celular/metabolismo , Humanos , Bicamadas Lipídicas/química , Bicamadas Lipídicas/metabolismo , Dados de Sequência Molecular , Fosfolipídeos/metabolismo , Ligação Proteica , Conformação Proteica , Solventes/química
20.
J Cardiovasc Electrophysiol ; 23(12): 1317-25, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22830441

RESUMO

INTRODUCTION: Cardiac resynchronization therapy (CRT) efficacy trials to date used atrial-synchronous biventricular pacing wherein there is no or minimal atrial pacing. However, bradycardia and chronotropic incompetence are common in this patient population. This trial was designed to evaluate the effect of atrial support pacing among heart failure patients receiving a CRT defibrillator. METHODS AND RESULTS: PEGASUS CRT was a multicenter, 3-arm, randomized study. At 6 weeks, patients were randomized to DDD mode at a lower rate of 40 bpm (DDD-40; control arm), or one of the following 2 treatment arms: DDD-70, or DDDR-40. The primary endpoint was a clinical composite endpoint that included all-cause mortality, heart failure events, NYHA functional class, and patient global self-assessment. Subjects were classified as improved, unchanged, or worsened at 12 months. There were 1,433 patients randomized, of whom 66% were male, mean age was 67 ± 11 years, and mean left ventricular ejection fraction was 23 ± 7%. The average follow-up time was 10.5 ± 3.5 months and 1,309 patients contributed to the primary endpoint. No significant differences were observed in the composite endpoint between either of the 2 treatment arms compared to the control arm (P>0.05 for both comparisons). Additionally, there were no differences among the groups in mortality or heart failure events. CONCLUSION: In advanced heart failure patients treated with CRT, atrial support pacing did not improve clinical outcomes compared to atrial tracking. However, atrial pacing did not adversely affect mortality or heart failure events.


Assuntos
Estimulação Cardíaca Artificial/mortalidade , Terapia de Ressincronização Cardíaca/mortalidade , Átrios do Coração , Insuficiência Cardíaca/mortalidade , Insuficiência Cardíaca/prevenção & controle , Disfunção Ventricular Esquerda/mortalidade , Disfunção Ventricular Esquerda/prevenção & controle , Idoso , Austrália/epidemiologia , Comorbidade , Feminino , Insuficiência Cardíaca/diagnóstico , Humanos , Incidência , Masculino , Fatores de Risco , Análise de Sobrevida , Taxa de Sobrevida , Resultado do Tratamento , Estados Unidos/epidemiologia , Disfunção Ventricular Esquerda/diagnóstico
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