| 1. |
- Zhu, Jie, et al.
(författare)
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Highly secretory expression of recombinant cowpea chlorotic mottle virus capsid proteins in Pichia pastoris and in-vitro encapsulation of ruthenium nanoparticles for catalysis
- 2020
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Ingår i: Protein Expression and Purification. - : Elsevier BV. - 1046-5928 .- 1096-0279. ; 174
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Tidskriftsartikel (refereegranskat)abstract
- The applications of viral protein cages have expanded rapidly into the fields of bionanotechnology and materials science. However, the low-cost production of viral capsid proteins (CPs) on a large scale is always a challenge. Herein, we develop a highly efficient expression system by constructing recombinant Pichia pastoris cells as a “factory” for the secretion of soluble cowpea chlorotic mottle virus (CCMV) CPs. Under optimal induction conditions (0.9 mg/mL of methanol concentration at 30 °C for 96 h), a high yield of approximately 95 mg/L of CCMV CPs was harvested from the fermentation supernatant with CPs purity >90%, which has significantly simplified the rest of the purification process. The resultant CPs are employed to encapsulate Ruthenium (Ru) nanoparticles (NPs) via in-vitro self-assembly to prepare hybrid nanocatalyst, i.e. Ru@virus-like particles (VLPs). The catalytic activity over Ru@VLPs was evaluated by reducing 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). The results indicate that, with the protection of protein cages, Ru NPs were highly stabilized during the catalytic reaction. This results in enhanced catalytic activity (reaction rate constant k = 0.14 min−1) in comparison with unsupported citrate-stabilized Ru NPs (Ru-CA) (k = 0.08 min−1). Additionally, comparatively lower activation energy over Ru@VLPs (approximately 32 kJ/mol) than that over Ru-CA (approximately 39 kJ/mol) could be attributed to the synergistic effect between Ru NPs and some functional groups such as amino groups (–NH2) on CPs that weakened the activation barrier of 4-NP reduction. Therefore, enhanced activity and decreased activation energy over Ru@VLPs demonstrated the superiority of Ru@VLPs to unsupported Ru-CA.
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| 2. |
- Lindström, Michelle, et al.
(författare)
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Lsm7 phase-separated condensates trigger stress granule formation
- 2022
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- Stress granules are non-membranous organelles connected to stress responses and age-related disease. Here, the authors identify a conserved yeast protein, Lsm7, that facilitates stress granule formation through dynamic liquid-liquid phase separation condensates upon 2-deoxy-D-glucose-induced stress. Stress granules (SGs) are non-membranous organelles facilitating stress responses and linking the pathology of age-related diseases. In a genome-wide imaging-based phenomic screen, we identify Pab1 co-localizing proteins under 2-deoxy-D-glucose (2-DG) induced stress in Saccharomyces cerevisiae. We find that deletion of one of the Pab1 co-localizing proteins, Lsm7, leads to a significant decrease in SG formation. Under 2-DG stress, Lsm7 rapidly forms foci that assist in SG formation. The Lsm7 foci form via liquid-liquid phase separation, and the intrinsically disordered region and the hydrophobic clusters within the Lsm7 sequence are the internal driving forces in promoting Lsm7 phase separation. The dynamic Lsm7 phase-separated condensates appear to work as seeding scaffolds, promoting Pab1 demixing and subsequent SG initiation, seemingly mediated by RNA interactions. The SG initiation mechanism, via Lsm7 phase separation, identified in this work provides valuable clues for understanding the mechanisms underlying SG formation and SG-associated human diseases.
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| 3. |
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| 4. |
- Wang, Jian, et al.
(författare)
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Bidirectional Associations between Parental Feeding Practices and Child Eating Behaviors in a Chinese Sample
- 2023
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Ingår i: Nutrients. - : MDPI. - 2072-6643. ; 16:1
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Tidskriftsartikel (refereegranskat)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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| 5. |
- Wang, Jian, et al.
(författare)
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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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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 19:6
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Tidskriftsartikel (refereegranskat)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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| 6. |
- Wang, Jian, et al.
(författare)
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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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Ingår i: Obesity Reviews. - : Wiley-Blackwell Publishing Inc.. - 1467-7881 .- 1467-789X. ; 25:4
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Forskningsöversikt (refereegranskat)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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| 7. |
- Wang, Jian, et al.
(författare)
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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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Ingår i: Nutrients. - : MDPI. - 2072-6643. ; 14:14
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Forskningsöversikt (refereegranskat)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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| 8. |
- Wang, Jian, et al.
(författare)
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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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Ingår i: Appetite. - : Elsevier. - 0195-6663 .- 1095-8304. ; 180
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Forskningsöversikt (refereegranskat)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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| 9. |
- Yang, Xiaoxue, et al.
(författare)
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Improved deep reinforcement learning for car-following decision-making
- 2023
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Ingår i: Physica A. - : Elsevier B.V.. - 0378-4371 .- 1873-2119. ; 624
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Tidskriftsartikel (refereegranskat)abstract
- Accuracy improvement of Car-following (CF) model has attracted much attention in recent years. Although a few studies incorporate deep reinforcement learning (DRL) to describe CF behaviors, proper design of reward function is still an intractable problem. This study improves the deep deterministic policy gradient (DDPG) car-following model with stacked denoising autoencoders (SDAE), and proposes a data-driven reward representation function, which quantifies the implicit interaction between ego vehicle and preceding vehicle in car-following process. The experimental results demonstrate that DDPG-SDAE model has superior ability of imitating driving behavior: (1) validating effectiveness of the reward representation method with low deviation of trajectory; (2) demonstrating generalization ability on two different trajectory datasets (HighD and SPMD); (3) adapting to three traffic scenarios clustered by a dynamic time warping distance based k-medoids method. Compared with Recurrent Neural Networks (RNN) and intelligent driver model (IDM), DDPG-SDAE model shows better performance on the deviation of speed and relative distance. This study demonstrates superiority of a novel reward extraction method fusing SDAE into DDPG algorithm and provides inspiration for developing driving decision-making model. © 2023 Elsevier B.V.
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| 10. |
- Yang, Xiaoxue, et al.
(författare)
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Stress granule-defective mutants deregulate stress responsive transcripts
- 2014
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Ingår i: PLoS Genetics. - : Public Library of Science (PLoS). - 1553-7390 .- 1553-7404. ; 10:11
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Tidskriftsartikel (refereegranskat)abstract
- To reduce expression of gene products not required under stress conditions, eukaryotic cells form large and complex cytoplasmic aggregates of RNA and proteins (stress granules; SGs), where transcripts are kept translationally inert. The overall composition of SGs, as well as their assembly requirements and regulation through stress-activated signaling pathways remain largely unknown. We have performed a genome-wide screen of S. cerevisiae gene deletion mutants for defects in SG formation upon glucose starvation stress. The screen revealed numerous genes not previously implicated in SG formation. Most mutants with strong phenotypes are equally SG defective when challenged with other stresses, but a considerable fraction is stress-specific. Proteins associated with SG defects are enriched in low-complexity regions, indicating that multiple weak macromolecule interactions are responsible for the structural integrity of SGs. Certain SG-defective mutants, but not all, display an enhanced heat-induced mutation rate. We found several mutations affecting the Ran GTPase, regulating nucleocytoplasmic transport of RNA and proteins, to confer SG defects. Unexpectedly, we found stress-regulated transcripts to reach more extreme levels in mutants unable to form SGs: stress-induced mRNAs accumulate to higher levels than in the wild-type, whereas stress-repressed mRNAs are reduced further in such mutants. Our findings are consistent with the view that, not only are SGs being regulated by stress signaling pathways, but SGs also modulate the extent of stress responses. We speculate that nucleocytoplasmic shuttling of RNA-binding proteins is required for gene expression regulation during stress, and that SGs modulate this traffic. The absence of SGs thus leads the cell to excessive, and potentially deleterious, reactions to stress.
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