1. |
- Cao, Hongwei, et al.
(author)
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Mechanistic insights into the changes of enzyme activity in food processing under microwave irradiation
- 2023
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In: Comprehensive Reviews in Food Science and Food Safety. - : John Wiley & Sons. - 1541-4337. ; 22:3, s. 2465-2487
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Research review (peer-reviewed)abstract
- Microwave (MW) and enzyme catalysis are two emerging processing tools in the field of food industry. Recently, MW has been widely utilized as a novel type of green and safe heating energy. However, the effect of MW irradiation on enzyme activity is not described clearly. The intrinsic mechanisms behind enzyme activation and inactivation remain obscure. To apply better MW to the field of enzyme catalysis, it is essential to gain insights into the mechanism of MW action on enzyme activity. This review summarizes the changes in various enzyme activity during food processing, especially under MW irradiation. The intrinsic mechanism of thermal and nonthermal effects of MW irradiation was analyzed from the perspective of enzyme reaction kinetics and spatial structure. MW irradiation temperature is a vital parameter affecting the catalytic activity of enzymes. Activation of the enzyme activity is achieved even at high MW power when the enzyme is operating at its optimum temperature. However, when the temperature exceeds the optimum temperature, the enzyme activity is inhibited. In addition to MW dielectric heating effect, nonthermal MW effects also alter the microenvironment of reactive system. Taken together, enzyme activity is influenced by both thermal and nonthermal MW effects.
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2. |
- Guo, Ming, et al.
(author)
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The Difference of Serum Protein Transport between Echinosides and Verbascoside
- 2020
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In: Journal of the Chemical Society of Pakistan. - : The chemical Society of Pakistan. - 0253-5106. ; 42:3, s. 369-382
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Journal article (peer-reviewed)abstract
- Verbascoside (VER) is the enzymatic hydrolysis product of echinacoside (ECH). The molecular structures of ECH and VER have different glucosyl groups so they bind to serum albumin in different ways, resulting in different pharmacological actions. In this report, we have examined the binding characteristics between human serum albumin (HSA) and ECH/VER by molecular modeling and spectroscopic approaches. Molecular modeling revealed that VER bound to HSA mainly through hydrogen bonds, van der Waals forces and hydrophobic forces. The spectroscopic results showed that the interactions between HSA and VER/ECH involved a static binding process, and the bonding strength of the VER-HSA complex was stronger than that of the ECH-HSA complex. The value of the binding distances (r) was low, which indicated the occurrence of energy transfer. The reaction conformational pattern of HSA-VER and HSA-ECH gave a "two-state model" based on fluorescent phase diagram analysis. According to the thermodynamic model, the main forces between interaction of VER and HSA were hydrogen bonds and van der Waals forces, whereas the interaction between ECH and HSA was hydrophobic force. The fluorescence polarization analysis demonstrated that the interaction between HSA and VER or ECH generated a non-covalent complex. Compared with ECH, VER was more likely to bind with HSA because of its smaller molecular size and low polarity. The results of the spectral analysis concurred with the molecular modeling data, which provides a helpful reference for the study of the molecular reaction mechanism of VER/ECH binding to HSA.
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3. |
- Peng, Lei, et al.
(author)
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Possible user-dependent CFD predictions of transitional flow in building ventilation
- 2016
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In: Building and Environment. - : Elsevier. - 0360-1323 .- 1873-684X. ; 99, s. 130-141
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Journal article (peer-reviewed)abstract
- A modified backward-facing step flow with a large expansion ratio of five (5) was modeled by 19 teams without benchmark solutions or experimental data for validation in an ISHVAC-COBEE July 2015 Tianjin Workshop, entitled as "to predict low turbulent flow". Different computational fluid dynamics (CFD) codes/software, turbulence models, boundary conditions, numerical schemes and convergent criteria were adopted based on the own CFD experience of each participating team. The largest coefficient of variation is larger than 50% and the largest relative maximum difference of penetration length is larger than 150%. The predicted non-dimensional penetration lengths as a function of the Reynolds number (1-10,000) are found to be significantly diverse among different teams. Even when the same turbulence model or even the laminar model is used, the difference in the predicted results is still notable among different teams. It indicates that the combined effects of a lack of general turbulence model, and possible errors in multiple decisions based on users' experience may have caused the observed significant difference. Prediction of transitional flows, as often observed in building ventilation, is shown to be still a very challenging task. This calls for a solid approach of validation and uncertainty assessment in CFD "experiments". The users are recommended to follow an existing guideline of uncertainty assessment of CFD predictions to minimize the errors and uncertainties in the future.
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4. |
- Qin, Haihong, et al.
(author)
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A Novel Adaptive Dead-Time Control Method for GaN-Based Motor Drives
- 2024
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In: IEEE Transactions on Energy Conversion. - 1558-0059 .- 0885-8969. ; In Press
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Journal article (peer-reviewed)abstract
- Compared to Si devices, Gallium Nitride (GaN) devices are more suitable for achieving high switching frequency in motor drive applications, thereby improving power density. However, increasing switching frequency can also lead to extra switching losses and poor total harmonic distortion (THD). A smaller dead-time can mitigate these issues, but conventional constant dead-time design methods struggle to ensure optimal performance across all load ranges. This paper proposes a novel adaptive dead-time control method for GaN high electron mobility transistors (HEMTs) in phase-legs to simultaneously enhance the efficiency and THD of motor drives. To achieve this, the detailed switching process of GaN HEMTs in a double-pulse test circuit is modeled and analyzed. The optimization principle of the dead-time setting is revealed, considering the tradeoff effect of dead-time on switching losses and THD. The adaptive dead-time control method dynamically adjusts the dead-time under different load conditions. The effectiveness of the proposed method is verified on a 1kW GaN-based permanent magnet synchronous machine drive platform. Extensive experimental results show that the proposed method can increase efficiency up to 0.85% at full load with a switching frequency of 100 kHz compared to constant dead-time. Meanwhile, THD is reduced by 1.44% under the same condition.
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5. |
- Wang, Jian, et al.
(author)
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Bidirectional Associations between Parental Feeding Practices and Child Eating Behaviors in a Chinese Sample
- 2023
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In: Nutrients. - : MDPI. - 2072-6643. ; 16:1
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Journal article (peer-reviewed)abstract
- BACKGROUND: Child eating behaviors (CEBs) and parental feeding practices (PFPs) play critical roles in childhood obesity. However, the bidirectional relationships between CEBs and PFPs remain equivocal. This longitudinal study aimed to explore their bidirectional relationships.METHODS: A convenience sample of 870 parents with preschoolers was recruited in this longitudinal study (Shanghai, China). Three non-responsive feeding practices (NFPs), three responsive feeding practices (RFPs), five CEBs, and covariates were collected using validated questionnaires at baseline and the 6-month follow-up. Cross-lagged analyses using structural equation modeling (SEM) were performed to examine their bidirectional relationships.RESULTS: Eight hundred and fifty-three parents completed questionnaires, with a response rate of 98%. The mean age of their children at baseline was 4.39 years (standard deviation = 0.72 years). Eighteen out of sixty longitudinal cross-lagged paths were statistically significant. Parental encouragement of healthy eating and content-restricted feeding were found to be bidirectionally associated with child food fussiness. Four parent-driven associations and one child-driven association were identified between RFPs and CEBs. For example, monitoring was negatively associated with children's unhealthy eating habits (β = -0.066, standard error (SE) = 0.025, p < 0.01). Eight child-driven associations and one parent-driven association were observed between NFPs and CEBs. For example, higher child satiety responsiveness predicted a higher pressure to eat (β = 0.057, SE = 0.029, p < 0.01) and the use of food as a reward (β = 0.083, SE = 0.031, p < 0.01).CONCLUSIONS: There were bidirectional, parent-driven, and child-driven associations. Parents should be encouraged to adopt RFPs to shape CEBs. Increasing parents' understanding of CEBs and providing them with reasonable coping strategies would help optimize PFPs.
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6. |
- Wang, Jian, et al.
(author)
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Empowering parents to optimize feeding practices with preschool children (EPO-Feeding) : A study protocol for a feasibility randomized controlled trial
- 2024
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In: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 19:6
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Journal article (peer-reviewed)abstract
- BACKGROUND: Parental feeding practices (PFPs) play a key role in fostering preschoolers' dietary habits and in mitigating the risk of childhood obesity. Nevertheless, parents often employ inappropriate feeding practices, leading to children's potential nutrition-related issues. Thus, research is needed to inform interventions that focus on optimizing feeding practices.METHODS: This protocol describes the evaluation of a novel intervention-Empowering Parents to Optimize Feeding Practices (EPO-Feeding Program). The program will be evaluated with a two-arm feasibility randomized controlled trial (RCT) in Yangzhou, China. The program includes four weekly group-based training sessions led by healthcare professionals for parents of preschool children. The intervention incorporates sessions, group discussions, motivational interviewing, and supplementary materials (e.g., key messages and educational videos) aimed at enhancing parents' knowledge, skills, and behaviours related to feeding practices. The primary outcomes include i) implementation feasibility, primarily assessed through retention rates; and ii) program acceptability through a survey and qualitative process evaluation. Secondary outcomes encompass the potential impacts on i) PFPs, ii) parental perception of child weight (PPCW), iii) parenting sense of competence, iv) children's eating behaviours, and v) child weight status. Quantitative analyses include descriptive estimates for evaluating the feasibility and linear mixed regression analysis for testing the potential effects. Qualitative valuation will use thematic framework analysis.DISCUSSION: If this study shows this program to be feasible to implement and acceptable to parents, it will be used to inform a fully powered trial to determine its effectiveness. The research will also help inform policy and practices in the context of child nutrition promotion, particularly regarding implementing group-based training sessions by healthcare providers in similar settings.TRIAL REGISTRATION: Clinicaltrials.gov, Protocol #NCT06181773, 20/11/2023.
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7. |
- Wang, Jian, et al.
(author)
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The effectiveness of interventions on changing caregivers' feeding practices with preschool children : A systematic review and meta-analysis
- 2024
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In: Obesity Reviews. - : Wiley-Blackwell Publishing Inc.. - 1467-7881 .- 1467-789X. ; 25:4
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Research review (peer-reviewed)abstract
- Caregivers' feeding practices are critical in shaping preschool children's eating habits and preventing childhood obesity. We conducted a systematic review and meta-analysis to evaluate the effectiveness of existing interventions targeting caregivers of preschool children, which aimed to promote child healthy eating and/or manage child weight and/or prevent child nutrition-related problems and included feeding practices as one of the outcomes. Eighteen studies with 18 intervention programs and 3887 respondents that completed baseline evaluations were eligible for data synthesis. Behavior change techniques (BCTs) frequently used included the following: instruction on how to perform the behavior and demonstration of the behavior. The pooled effects of randomized controlled trials (RCTs) on pressure to eat (pooled standardized mean difference [SMD] = 0.61; 95%CI: -1.16, -0.06), use of food as a reward (pooled SMD = -0.31; 95%CI: -0.61, -0.01), and emotional feeding (pooled SMD = -0.36; 95%CI: -0.66, -0.06) were found statistically significant compared with control groups at post-intervention. However, there were no pooled effects on restrictive feeding and pressure to eat at other follow-ups or on other feeding practices at post-intervention. Interventions may have short-term effects on decreasing the adoption of coercive control. Future interventions should directly and adequately optimize feeding practices, include components of individual support, and contribute to the maintenance of the effects over the long term.
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8. |
- Wang, Jian, et al.
(author)
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The Relationships between Caregivers' Concern about Child Weight and Their Non-Responsive Feeding Practices : A Systematic Review and Meta-Analysis
- 2022
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In: Nutrients. - : MDPI. - 2072-6643. ; 14:14
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Research review (peer-reviewed)abstract
- BACKGROUND: It is unclear whether caregivers' concern about child weight impacts their non-responsive feeding practices. This systematic review aimed to examine their relationships.METHODS: A systematic search of PubMed, Embase, PsycINFO, Web of Science core collection, CINAHL and grey literature was conducted from inception to March 2022, following PRISMA guidelines. Data synthesis was performed using a semi-quantitative approach and a meta-analysis.RESULTS: A total of 35 studies with 22,933 respondents were included in the review for semi-quantitative analyses. Thirty-four studies examined 52 associations between concern about child weight and restriction with 40 statistically significant associations being observed. A total of 34 relationships between concern about child weight and pressure to eat were investigated, with 12 being statistically significant. The pooled regression coefficients (β) demonstrated that caregivers' concern about child overweight was positively associated with restriction (β = 0.22; 95%CI: 0.12, 0.31), negatively associated with use of food as a reward (β = -0.06; 95%CI: -0.11, -0.01), and not statistically associated with pressure to eat (β = -0.05; 95%CI: -0.13, 0.04). The pooled odds ratios (ORs) indicated that caregivers who were concerned about child overweight were found to use restrictive feeding more often (OR = 2.34; 95%CI: 1.69, 3.23), while less frequently adopting pressure to eat (OR = 0.76; 95%CI: 0.59, 0.98) compared with those without concerns. The results also showed that caregivers who were concerned about child underweight were more likely to force their children to eat (OR = 1.83; 95%CI: 1.44, 2.33) than those without concerns.CONCLUSION: Caregivers' concern about child weight may be an important risk factor for non-responsive feeding practices. Thus, interventions are needed to focus on managing and relieving caregivers' excessive concern about child weight, especially overweight, which may optimize feeding practices and subsequently contribute to child health.
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9. |
- Wang, Jian, et al.
(author)
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The relationships between caregivers' self-reported and visual perception of child weight and their non-responsive feeding practices : A systematic review and meta-analysis.
- 2023
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In: Appetite. - : Elsevier. - 0195-6663 .- 1095-8304. ; 180
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Research review (peer-reviewed)abstract
- BACKGROUND: The impacts of caregivers' perception of child weight on their non-responsive feeding practices are inconclusive. This systematic review aimed to examine their relationships.METHODS: A systematic search of five databases was conducted from inception to March 2022, following PRISMA guidelines. Data synthesis was performed using semi-quantitative approach and meta-analysis.RESULTS: Twenty-two studies with 12005 respondents were included for semi-quantitative analyses. Eighteen studies examined 26 associations between caregivers' perception of child weight and food restriction with 12 statistically significant associations being observed. A total of 22 relationships between caregivers' perception of child weight and pressure to eat were investigated, with 13 being statistically significant. The statistically significant associations consistently reported that caregivers' visual and self-reported perception of child weight was positively associated with their restrictive feeding and negatively associated with pressure to eat. The pooled odds ratios (ORs) indicated that caregivers who perceived their child as overweight were found to apply pressure to eat less frequently (OR = 0.61; 95%CI: 0.44, 0.84) compared with those who did not. However, caregivers' perception of child weight was not statistically significantly associated with restrictive feeding (OR = 1.37; 95%CI: 0.74, 2.55).CONCLUSION: Caregivers' self-reported and visual perception of child weight may be important risk factors for non-responsive feeding practices, particularly food restriction and pressure to eat. Thus, interventions need to consider the role of caregivers' perception of child weight, which may optimize feeding practices. Furthermore, longitudinal and intervention-based studies using validated measurements while controlling for potential covariates are needed to provide more evidence on their causal relationships.
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10. |
- Wang, Xiaoxue, et al.
(author)
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Resolving conflicting models of late Miocene East Asian summer monsoon intensity recorded in Red Clay deposits on the Chinese Loess Plateau
- 2022
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In: Earth-Science Reviews. - : Elsevier. - 0012-8252 .- 1872-6828. ; 234, s. 104200-104200
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Journal article (peer-reviewed)abstract
- Considerable debate exists regarding how the East Asian summer monsoon (EASM) varied over the late Miocene, limiting our ability to understand the long-term evolution and forcing of this system. Much understanding of EASM variation over the late Cenozoic is based on loess magnetic susceptibility (χlf) records from the Chinese Loess Plateau (CLP). During Pliocene-Quaternary times, χlf decreases from southeast to northwest across the CLP, consistent with the modern monsoonal climate pattern. However, the χlf records over the late Miocene show different patterns, with lower values on the central CLP sandwiched between higher values of the eastern and western CLP, a pattern inconsistent with predictions based on monsoon climate. Here we propose a hypothesis to explain this conundrum, and advance knowledge of late Miocene EASM variations. As with other parts of the CLP, high late Miocene χlf values on the western CLP were caused by increases in the ultrafine ferrimagnetic grain content. However, we argue that part of the ultrafine ferrimagnetic grain increase on the western CLP was due to detrital input derived from eroding surface soil cover on the uplifting bounding mountains of the northeastern Tibetan Plateau and western Qinling. Loess provenance data and independent evidence regarding uplift timing of the northeastern Tibetan Plateau support our hypothesis. We propose that the eastern CLP χlf more faithfully reflects EASM intensity; indeed, eastern CLP χlf data show relatively low values over the late Miocene, indicating a weak EASM, consistent with inferences from marine sediments. Therefore, our work reconciles conflicting evidence regarding late Miocene EASM intensity and deepens our understanding of the underlying monsoon forcing mechanisms. We conclude that global climate, instead of Tibetan uplift, is the major mechanism driving EASM precipitation evolution over the late Miocene.
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