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1.
J Sports Sci ; 37(13): 1464-1471, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30668281

RESUMO

This study investigated the effects of two separate doses of sodium bicarbonate (NaHCO3) on 4 km time trial (TT) cycling performance and post-exercise acid base balance recovery in hypoxia. Fourteen club-level cyclists completed four cycling TT's, followed by a 40 min passive recovery in normobaric hypoxic conditions (FiO2 = 14.5%) following one of either: two doses of NaHCO3 (0.2 g.kg-1 BM; SBC2, or 0.3 g.kg-1 BM; SBC3), a taste-matched placebo (0.07 g.kg-1 BM sodium chloride; PLA), or a control trial in a double-blind, randomized, repeated-measures and crossover design study. Compared to PLA, TT performance was improved following SBC2 (p = 0.04, g = 0.16, very likely beneficial), but was improved to a greater extent following SBC3 (p = 0.01, g = 0.24, very likely beneficial). Furthermore, a likely benefit of ingesting SBC3 over SBC2 was observed (p = 0.13, g = 0.10), although there was a large inter-individual variation. Both SBC treatments achieved full recovery within 40 min, which was not observed in either PLA or CON following the TT. In conclusion, NaHCO3 improves 4 km TT performance and acid base balance recovery in acute moderate hypoxic conditions, however the optimal dose warrants an individual approach.


Assuntos
Equilíbrio Ácido-Base/efeitos dos fármacos , Desempenho Atlético/fisiologia , Ciclismo/fisiologia , Substâncias para Melhoria do Desempenho/administração & dosagem , Bicarbonato de Sódio/administração & dosagem , Adolescente , Adulto , Estudos Cross-Over , Método Duplo-Cego , Feminino , Gastroenteropatias/induzido quimicamente , Frequência Cardíaca , Humanos , Concentração de Íons de Hidrogênio , Hipóxia , Masculino , Oxigênio/sangue , Percepção , Substâncias para Melhoria do Desempenho/efeitos adversos , Substâncias para Melhoria do Desempenho/sangue , Esforço Físico , Bicarbonato de Sódio/efeitos adversos , Bicarbonato de Sódio/sangue , Adulto Jovem
2.
Eur J Appl Physiol ; 118(12): 2489-2498, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30196448

RESUMO

PURPOSE: Exacerbated hydrogen cation (H+) production is suggested to be a key determinant of fatigue in acute hypoxic conditions. This study, therefore, investigated the effects of NaHCO3 ingestion on repeated 4 km TT cycling performance and post-exercise acid-base balance recovery in acute moderate hypoxic conditions. METHODS: Ten male trained cyclists completed four repeats of 2 × 4 km cycling time trials (TT1 and TT2) with 40 min passive recovery, each on different days. Each TT series was preceded by supplementation of one of the 0.2 g kg-1 BM NaHCO3 (SBC2), 0.3 g kg-1 BM NaHCO3 (SBC3), or a taste-matched placebo (0.07 g kg-1 BM sodium chloride; PLA), administered in a randomized order. Supplements were administered at a pre-determined individual time to peak capillary blood bicarbonate concentration ([HCO3-]). Each TT series was also completed in a normobaric hypoxic chamber set at 14.5% FiO2 (~ 3000 m). RESULTS: Performance was improved following SBC3 in both TT1 (400.2 ± 24.1 vs. 405.9 ± 26.0 s; p = 0.03) and TT2 (407.2 ± 29.2 vs. 413.2 ± 30.8 s; p = 0.01) compared to PLA, displaying a very likely benefit in each bout. Compared to SBC2, a likely and possible benefit was also observed following SBC3 in TT1 (402.3 ± 26.5 s; p = 0.15) and TT2 (410.3 ± 30.8 s; p = 0.44), respectively. One participant displayed an ergolytic effect following SBC3, likely because of severe gastrointestinal discomfort, as SBC2 still provided ergogenic effects. CONCLUSION: NaHCO3 ingestion improves repeated exercise performance in acute hypoxic conditions, although the optimal dose is likely to be 0.3 g kg-1 BM.


Assuntos
Alcalose/fisiopatologia , Tolerância ao Exercício , Treinamento Intervalado de Alta Intensidade , Hipóxia/fisiopatologia , Equilíbrio Ácido-Base , Adulto , Alcalose/tratamento farmacológico , Bicarbonatos/sangue , Carbonatos/administração & dosagem , Carbonatos/uso terapêutico , Humanos , Masculino , Distribuição Aleatória
3.
JCO Clin Cancer Inform ; 4: 336-345, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32324447

RESUMO

PURPOSE: Zero-footprint Web architecture enables imaging applications to be deployed on premise or in the cloud without requiring installation of custom software on the user's computer. Benefits include decreased costs and information technology support requirements, as well as improved accessibility across sites. The Open Health Imaging Foundation (OHIF) Viewer is an extensible platform developed to leverage these benefits and address the demand for open-source Web-based imaging applications. The platform can be modified to support site-specific workflows and accommodate evolving research requirements. MATERIALS AND METHODS: The OHIF Viewer provides basic image review functionality (eg, image manipulation and measurement) as well as advanced visualization (eg, multiplanar reformatting). It is written as a client-only, single-page Web application that can easily be embedded into third-party applications or hosted as a standalone Web site. The platform provides extension points for software developers to include custom tools and adapt the system for their workflows. It is standards compliant and relies on DICOMweb for data exchange and OpenID Connect for authentication, but it can be configured to use any data source or authentication flow. Additionally, the user interface components are provided in a standalone component library so that developers can create custom extensions. RESULTS: The OHIF Viewer and its underlying components have been widely adopted and integrated into multiple clinical research platforms (e,g Precision Imaging Metrics, XNAT, LabCAS, ISB-CGC) and commercial applications (eg, Osirix). It has also been used to build custom imaging applications (eg, ProstateCancer.ai, Crowds Cure Cancer [presented as a case study]). CONCLUSION: The OHIF Viewer provides a flexible framework for building applications to support imaging research. Its adoption could reduce redundancies in software development for National Cancer Institute-funded projects, including Informatics Technology for Cancer Research and the Quantitative Imaging Network.


Assuntos
Neoplasias , Interface Usuário-Computador , Diagnóstico por Imagem , Humanos , Armazenamento e Recuperação da Informação , Internet , Neoplasias/diagnóstico por imagem , Software
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