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1.
Paediatr Child Health ; 28(6): 357-361, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37744755

RESUMO

Objectives: Paediatricians are essential in guiding families on screen time use as digital media becomes increasingly prevalent. While this has been highlighted through the COVID-19 pandemic there is no literature on paediatricians' awareness of Canadian screen time guidelines, or perception of these guidelines during this time. The aim of this study was to assess pediatricians' knowledge, attitudes, and comfort with the Canadian Paediatric Society's (CPS) screen time guidelines, specifically during the COVID-19 pandemic. Methods: Our survey was developed by a paediatric resident and paediatric endocrinologist, reviewed by local experts, and sent electronically to members of the CPS Community and Developmental Paediatrics sections. Results: All 53 respondents were aware of current CPS screen time guidelines, and the majority self-reported fair to excellent knowledge of guidelines for both age groups (<5 years and school-aged children/adolescents). Over 80% noticed increased screen use during the pandemic, and 98% were somewhat or very concerned about screen use and their patients' health and well-being. Pediatricians reported concerns about associations between increased screen time with worsening behaviour, mental health concerns, obesity, and sedentary lifestyle. The greatest barrier to reducing screen time was perceived insufficient motivation or support from caregivers/families. Conclusions: Responding Canadian paediatricians are knowledgeable and comfortable with current screen time guidelines in Canada. Despite this, there is increasing concern with health outcomes associated with screen use. These results highlight paediatricians' important role in counselling patients and may encourage further local advocacy and public education around screen use and associated health risks in children.

2.
Microb Cell Fact ; 15(1): 133, 2016 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-27485110

RESUMO

BACKGROUND: In our previous study, the feasibility of Rubisco-based engineered E. coli (that contains heterologous phosphoribulokinase (PrkA) and Rubisco) for in situ CO2 recycling during the fermentation of pentoses or hexoses was demonstrated. Nevertheless, it is perplexing to see that only roughly 70 % of the carbon fed to the bacterial culture could be accounted for in the standard metabolic products. This low carbon recovery during fermentation occurred even though CO2 emission was effectively reduced by Rubisco-based engineered pathway. RESULTS: In this study, the heterologous expression of form I Rubisco was found to enhance the accumulation of pyruvate in Escherichia coli MZLF [E. coli BL21(DE3) Δzwf, Δldh, Δfrd]. This may be attributed to the enhanced glycolytic reaction supported by the increased biomass and the ethanol/acetate ratio. Besides, it was found that the transcription of arcA (encodes the redox-dependent transcriptional activators ArcA that positively regulates the transcription of pyruvate formate-lyase) was down-regulated in the presence of Rubisco. The enhanced accumulation of pyruvate also occurs when PrkA is co-expressed with Rubisco in E. coli MZLF. Furthermore, E. coli containing Rubisco-based engineered pathway has a distinct profile of the fermentation products, indicating CO2 was converted into fermentation products. By analyzing the ratio of total C-2 (2-carbon fermentation products) to total C-1 (1-carbon fermentation product) of MZLFB (MZLF containing Rubisco-based engineered pathway), it is estimated that 9 % of carbon is directed into Rubisco-based engineered pathway. CONCLUSIONS: Here, we report for the first time the complete profile of fermentation products using E. coli MZLF and its derived strains. It has been shown that the expression of Rubisco alone in MZLF enhances the accumulation of pyruvate. By including the contribution of pyruvate accumulation, the perplexing problem of low carbon recovery during fermentation by E. coli containing Rubisco-based engineered pathway has been solved. 9 % of glucose consumption is directed from glycolysis to Rubisco-based engineered pathway in MZLFB. The principle characteristics of mixotroph MZLFB are the high bacterial growth and the low CO2 emission.


Assuntos
Dióxido de Carbono/metabolismo , Escherichia coli/metabolismo , Metaboloma , Ribulose-Bifosfato Carboxilase/metabolismo , Escherichia coli/genética , Estudos de Viabilidade , Fermentação , Engenharia Genética , Piruvatos/metabolismo , Recombinação Genética , Ribulose-Bifosfato Carboxilase/genética
3.
Toxics ; 10(10)2022 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-36287836

RESUMO

The application of semiconductor photocatalysts with narrow band gaps is hindered by the rapid recombination of electron-hole pairs and limitation of multiple reactive oxygen species (ROS) synchronous generation. A n-n-type direct Z-scheme heterostructured photocatalyst was constructed based on the staggered band alignment of bismuth tungstate (Bi2WO6) and indium zinc sulfide (ZnIn2S4) to reveal the synergistic effect of charge separation and multiple ROS synchronous generation on boosting photocatalytic performance. Under irradiation, electrons in the conduction band (CB) of Bi2WO6 and holes in the valence band (VB) of ZnIn2S4 recombined at interface to prolong the lifetime of electrons in the CB of ZnIn2S4 and holes in the VB of Bi2WO6. Meanwhile, the multiple ROS synchronously generated to oxidize pollutant due to the strong redox ability of electrons of ZnIn2S4 and holes of Bi2WO6, which was determined by the CB potential of ZnIn2S4 and VB potential of Bi2WO6. The results provided valuable insights for the application of photocatalysts with a narrow band gap in the field of water pollution control.

4.
J Adolesc Health ; 56(2): 215-22, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25620305

RESUMO

PURPOSE: To explore the association between developmental assets (characteristics, experiences, and relationships that shape healthy development) and food insecurity among adolescents from a low-income urban community. METHODS: This mixed-methods study occurred in two phases. In phase 1, using a census approach, 2,350 6th to 12th graders from the public school district completed an anonymous survey that included the developmental assets profile (DAP), the youth self-report form of the Core Food Security Module, and demographic questions. Logistic and multinomial regression analyses determined independent associations between developmental assets and food security adjusting for demographics. In phase 2, 20 adult key informant interviews and four semistructured student focus groups were performed to explain findings from phase 1. RESULTS: On average, DAP scores were consistent with national norms. Food insecurity was prevalent; 14.9% reported low food security and 8.6% very low food security (VLFS). Logistic regression revealed that higher DAP was associated with lower odds of food insecurity (odds ratio [OR], .96; 95% confidence interval [CI], .95-.97); family assets drove this association (OR, .93; 95% CI, .91-.95). In multinomial regression modeling, these associations persisted, and paradoxically, higher community assets were also associated with VLFS (ORVLFS, 1.08; 95% CI, 1.04-1.13). Qualitative analyses suggested that greater need among VLFS youth led to increased connections to community resources despite barriers to access such as stigma, home instability, and cultural differences. CONCLUSION: Food insecurity is a pervasive problem among adolescents from low-income communities and is associated with lower developmental assets, particularly family assets. The fact that community assets were higher among VLFS youth underscores the importance of community-level resources in struggling areas.


Assuntos
Saúde do Adolescente/economia , Abastecimento de Alimentos/economia , Pobreza/estatística & dados numéricos , Adolescente , Adulto , Estudos Transversais , Feminino , Declarações Financeiras , Humanos , Modelos Logísticos , Masculino , Características de Residência , Fatores de Risco , Fatores Socioeconômicos
5.
Bioresour Technol ; 187: 189-197, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25846189

RESUMO

In this study, Rubisco-based engineered Escherichia coli, containing two heterologous enzymes of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and phosphoribulokinase (PrkA), has been shown to be capable of the in situ recycling of carbon dioxide (CO2) during glycolysis. Two alternative approaches have been proposed to further enhance the carbon flow from glycolysis to a Rubisco-based pathway through the non-oxidative pentose phosphate pathway (NOPPP). The first is achieved by elevating the expression of transketolase I (TktA) and the second by blocking the native oxidation-decarboxylation reaction of E. coli by deleting the zwf gene from the chromosome (designated as JB/pTA and MZB, respectively). Decreases in the CO2 yield and the CO2 evolution per unit mole of ethanol production by at least 81% and 40% are observed. It is demonstrated in this study that the production of one mole of ethanol using E. coli strain MZB, the upper limit of CO2 emission is 0.052mol.


Assuntos
Dióxido de Carbono/metabolismo , Escherichia coli/metabolismo , Etanol/metabolismo , Glicólise/fisiologia , Via de Pentose Fosfato/fisiologia , Ribulose-Bifosfato Carboxilase/metabolismo , Conservação dos Recursos Naturais/métodos , Escherichia coli/classificação , Escherichia coli/genética , Etanol/isolamento & purificação , Melhoramento Genético/métodos , Oxirredução , Ribulose-Bifosfato Carboxilase/genética
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