| 1. |
- Beal, Jacob, et al.
(författare)
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Robust estimation of bacterial cell count from optical density
- 2020
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Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
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| 2. |
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- 2019
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Tidskriftsartikel (refereegranskat)
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| 3. |
- Jin, Binghan, et al.
(författare)
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Abdominal Adiposity and Total Body Fat as Predictors of Cardiometabolic Health in Children and Adolescents With Obesity
- 2020
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Ingår i: Frontiers in Endocrinology. - : FRONTIERS MEDIA SA. - 1664-2392. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Objective:We aimed to assess the role of adipose tissue distribution in cardiometabolic risk (in particular insulin sensitivity) in a population of children and adolescents with obesity. Methods:In this cross-sectional study, participants were 479 children and adolescents with obesity (322 boys and 157 girls) aged 3 to 18 years attending the Children's Hospital at Zhejiang University School of Medicine (Hangzhou, China). Clinical assessments included anthropometry, body composition (DXA scans), carotid artery ultrasounds, and OGTT. Insulin sensitivity was assessed using the Matsuda index. Participants were stratified into groups by sex and pubertal stage. Key predictors were DXA-derived android-to-gynoid-fat ratio (A/G) and total body fat percentage (TBF%). Results:Irrespective of sex and pubertal stage, there was a strong association between increasing A/G (i.e., greater abdominal adiposity) and lower insulin sensitivity. In multivariable models, every 0.1 increase in A/G was associated with a reduction in insulin sensitivity in prepubertal boys [-29% (95% CI -36%, -20%);p< 0.0001], pubertal boys [-13% (95% CI -21%, -6%);p= 0.001], and pubertal girls [-16% (95% CI -24%, -6%);p= 0.002]. In contrast, TBF% was not associated with insulin sensitivity when A/G was adjusted for, irrespective of pubertal stage or sex. In addition, every 0.1 increase in A/G was associated with increased likelihood of dyslipidemia in prepubertal boys [adjusted odds ratio (aOR) 1.62 (95% CI 1.05, 2.49)], impaired glucose tolerance in pubertal boys [aOR 1.64 (95% CI 1.07, 2.51)] and pubertal girls [aOR 1.81 (95% CI 1.10, 2.98)], and odds of NAFLD in both prepubertal [aOR 2.57 (95% CI 1.56, 4.21)] and pubertal [aOR 1.69 (95% CI 1.18, 2.40)] boys. In contrast, higher TBF% was only associated with higher fasting insulin and ALT in pubertal boys, being also predictive of NAFLD in this group [aOR 1.15 per percentage point (95% CI 1.06, 1.26)], but was not associated with the likelihood of other cardiometabolic outcomes assessed in any group. Conclusions:A/G is a much stronger independent predictor of cardiometabolic risk factors in children and adolescents with obesity in China, particularly glucose metabolism.
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| 4. |
- Li, Xinyu, et al.
(författare)
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Biodegradable MOFilters for Effective Air Filtration and Sterilization by Coupling MOF Functionalization and Mechanical Polarization of Fibrous Poly(lactic acid)
- 2023
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 15:22, s. 26812-26823
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Tidskriftsartikel (refereegranskat)abstract
- High-performance air filtration materials are importantfor addressingthe airborne pollutants. Herein, we propose an unprecedented accessto biodegradable poly-(lactic acid) (PLA)-based MOFilters with excellentfiltering performance and antibacterial activity. The fabricationinvolved a stepwise in situ growth of zeolitic imidazolate framework-8(ZIF-8) crystals at the surface of microfibrous PLA membranes, followedby mechanical polarization under high pressure and low temperature(5 MPa, 40 degrees C) to trigger the ordered alignment of dipoles inPLA chains and ZIF-8. The unique structural features allowed thesePLA-based MOFilters to achieve an exceptional combination of excellenttensile properties, high dielectric constant (up to 2.4 F/m), andenhanced surface potential as high as 4 kV. Arising from the remarkablesurface activity and electrostatic adsorption effect, a significantincrease (from over 12% to nearly 20%) in PM0.3 filtrationefficiency was observed for the PLA-based MOFilters compared to thatof pure PLA counterparts, with weak relation to the airflow velocities(10-85 L/min). Moreover, the air resistance was controlledat a considerably low level for all the MOFilters, that is, below183 Pa even at 85 L/min. It is worth noting that distinct antibacterialproperties were achieved for the MOFilters, as illustrated by theinhibitive rates of 87 and 100% against Escherichiacoli and Staphylococcus aureus, respectively. The proposed concept of PLA-based MOFilters offersunprecedented multifunction integration, which may fuel the developmentof biodegradable versatile filters with high capturing and antibacterialperformances yet desirable manufacturing feasibility.
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| 5. |
- Li, Xinyi, et al.
(författare)
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Phylogenetic analysis and functional characterization of norcoclaurine synthase involved in benzylisoquinoline alkaloids biosynthesis in Stephania tetrandra
- 2023
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Ingår i: Journal of Cellular Physiology. - 1097-4652 .- 0021-9541. ; In Press
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Tidskriftsartikel (refereegranskat)abstract
- Benzylisoquinoline alkaloids (BIAs) are a class of secondary metabolites that possess diverse pharmaceutical properties and are exclusively accumulated in specific plant genera. The Pictet–Spengler condensation, catalyzed by norcoclaurine synthase (NCS), represents a key enzymatic reaction in the biosynthetic pathway of BIAs. While NCS genes have been identified in several plant families such as Papaveraceae, Berberidaceae, and Ranunculaceae, no NCS genes have been reported in Menispermaceae, which is another genus known to accumulate BIAs. Here, NCSs were isolated and functionally characterized from the Menispermaceae family plant Stephania tetrandra. In vitro enzyme assay identified two functional StNCSs which could catalyze the formation of (S)-norcoclaurine. These functionally characterized genes were then integrated into engineered yeast to enable the production of norcoclaurine. Phylogenetic analysis of the NCS enzymes revealed that the StNCSs predominantly clustered into two clades. The functional StNCSs clustered with known NCSs, highlighting the presence of a specific NCS catalytic domain. This study not only provides additional genetic components for the synthetic biology-based production of BIAs in yeast but also contributes to the understanding of the phylogenetic relationships and structure–function relationship of NCS genes involved in the origin and production of BIAs.
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| 6. |
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| 7. |
- Deng, Min, et al.
(författare)
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Genome-wide association analyses in Han Chinese identify two new susceptibility loci for amyotrophic lateral sclerosis
- 2013
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Ingår i: Nature Genetics. - : Nature Publishing Group. - 1061-4036 .- 1546-1718. ; 45:6, s. 697-
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Tidskriftsartikel (refereegranskat)abstract
- To identify susceptibility genes for amyotrophic lateral sclerosis (ALS), we conducted a genome-wide association study (GWAS) in 506 individuals with sporadic ALS and 1,859 controls of Han Chinese ancestry. Ninety top SNPs suggested by the current GWAS and 6 SNPs identified by previous GWAS were analyzed in an independent cohort of 706 individuals with ALS and 1,777 controls of Han Chinese ancestry. We discovered two new susceptibility loci for ALS at 1q32 (CAMK1G, rs6703183, P-combined = 2.92 x 10(-8), odds ratio (OR) = 1.31) and 22p11 (CABIN1 and SUSD2, rs8141797, P-combined = 2.35 x 10(-9), OR = 1.52). These two loci explain 12.48% of the overall variance in disease risk in the Han Chinese population. We found no association evidence for the previously reported loci in the Han Chinese population, suggesting genetic heterogeneity of disease susceptibility for ALS between ancestry groups. Our study identifies two new susceptibility loci and suggests new pathogenic mechanisms of ALS.
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| 8. |
- Huang, Liping, et al.
(författare)
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The contribution of sodium reduction and potassium increase to the blood pressure lowering observed in the Salt Substitute and Stroke Study
- 2024
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Ingår i: Journal of Human Hypertension. - : Springer Nature. - 0950-9240 .- 1476-5527. ; 38:4, s. 298-306
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Tidskriftsartikel (refereegranskat)abstract
- The Salt Substitute and Stroke Study (SSaSS) demonstrated significant reductions in systolic blood pressure (SBP), and the risk of stroke, major cardiovascular events and total mortality with the use of potassium-enriched salt. The contribution of sodium reduction versus potassium increase to these effects is unknown. We identified four different data sources describing the association between sodium reduction, potassium supplementation and change in SBP. We then fitted a series of models to estimate the SBP reductions expected for the differences in sodium and potassium intake in SSaSS, derived from 24-h urine collections. The proportions of the SBP reduction separately attributable to sodium reduction and potassium supplementation were calculated. The observed SBP reduction in SSaSS was -3.3 mmHg with a corresponding mean 15.2 mmol reduction in 24-h sodium excretion and a mean 20.6 mmol increase in 24-h potassium excretion. Assuming 90% of dietary sodium intake and 70% of dietary potassium intake were excreted through urine, the models projected falls in SBP of between -1.67 (95% confidence interval: -4.06 to +0.73) mmHg and -5.33 (95% confidence interval: -8.58 to -2.08) mmHg. The estimated proportional contribution of sodium reduction to the SBP fall ranged between 12 and 39% for the different models fitted. Sensitivity analyses assuming different proportional urinary excretion of dietary sodium and potassium intake showed similar results. In every model, the majority of the SBP lowering effect in SSaSS was estimated to be attributable to the increase in dietary potassium rather than the fall in dietary sodium.
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| 9. |
- Jain, Neha, et al.
(författare)
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Inhibition of curli assembly and Escherichia coli biofilm formation by the human systemic amyloid precursor transthyretin
- 2017
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 114:46, s. 12184-12189
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Tidskriftsartikel (refereegranskat)abstract
- During biofilm formation, Escherichia coli and other Enterobacteriaceae produce an extracellular matrix consisting of curli amyloid fibers and cellulose. The precursor of curli fibers is the amyloidogenic protein CsgA. The human systemic amyloid precursor protein transthyretin (TTR) is known to inhibit amyloid-β (Aβ) aggregation in vitro and suppress the Alzheimer’s-like phenotypes in a transgenic mouse model of Aβ deposition. We hypothesized that TTR might have broad antiamyloid activity because the biophysical properties of amyloids are largely conserved across species and kingdoms. Here, we report that both human WT tetrameric TTR (WT-TTR) and its engineered nontetramer-forming monomer (M-TTR, F87M/L110M) inhibit CsgA amyloid formation in vitro, with M-TTR being the more efficient inhibitor. Preincubation of WT-TTR with small molecules that occupy the T4 binding site eliminated the inhibitory capacity of the tetramer; however, they did not significantly compromise the ability of M-TTR to inhibit CsgA amyloidogenesis. TTR also inhibited amyloid-dependent biofilm formation in two different bacterial species with no apparent bactericidal or bacteriostatic effects. These discoveries suggest that TTR is an effective antibiofilm agent that could potentiate antibiotic efficacy in infections associated with significant biofilm formation.
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| 10. |
- Li, Xinbao, et al.
(författare)
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Dehydrogenation mechanisms of liquid organic hydrogen carriers over Pt, Pd, Rh, and Ni surfaces : Cyclohexane as a model compound
- 2021
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Ingår i: Applied Surface Science. - : Elsevier BV. - 0169-4332. ; 543
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Tidskriftsartikel (refereegranskat)abstract
- In order to make a better understanding of dehydrogenation mechanisms of liquid organic hydrogen carriers, cyclohexane was selected as a model compound to carry out its decomposition studies over Pt(1 1 1), Pd(1 1 1), Rh(1 1 1), and Ni(1 1 1) surfaces via periodic density functional theory calculations. The adsorption geometries and adsorption energies of reaction intermediates were presented. Similar linear relationships of the adsorption energies with respect to the number of hydrogen removal over these four surfaces were revealed for C6Hx* (x = 8–12). Seven elementary reactions for cyclohexane successive dehydrogenation to C6H5* were considered. The initial dehydrogenation of C6H12* to generate C6H11* were identified as the rate-determining steps over all surfaces, association with activation energies of 1.04, 1.06, 0.96, and 1.14 eV for Pt(1 1 1), Pd(1 1 1), Rh(1 1 1), and Ni(1 1 1), respectively. The reactivity of dehydrogenation was in the order of Rh(1 1 1) > Pt(1 1 1) > Pd(1 1 1) > Ni(1 1 1).
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| 11. |
- Liu, Xiaomei, et al.
(författare)
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Cognitive Benefit of a Multidomain Intervention for Older Adults at Risk of Cognitive Decline : A Cluster- Randomized Controlled Trial
- 2023
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Ingår i: The American journal of geriatric psychiatry. - : Elsevier BV. - 1064-7481 .- 1545-7214. ; 31:3, s. 197-209
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Tidskriftsartikel (refereegranskat)abstract
- Objective: We sought to assess cognitive benefits of a community-based multi -domain intervention for improving cognition among older adults at risk of cog-nitive decline (COMBAT). Design: A two-armed cluster-randomized controlled trial. Setting and Participants: Community-dwelling older adults aged 60 years or older and were at risk of cognitive decline (n = 209). Intervention: In this 9-month intervention study, 10 community hospitals in Beijing, China, were randomized (1:1) to receive either a multidomain inter-vention of meditation, cognitive training, exercise, and nutrition counseling or usual care. The intervention was delivered with weekly 1-hour group training sessions and weekly home homework. Measurements: Primary outcome was change in cognition as measured by a composite Z score of seven cognitive tests. Secondary outcomes included subjective cognitive abilities, positive and nega-tive affective experiences, physical activity, and dietary habits. Assessments were administered at baseline, end of the intervention, and 1 year after com-pleting the intervention (1-year follow-up). Results: Immediately after the intervention, the intervention group showed significant enhancement in cogni-tive performance (p = 0.026). The between-group difference in the Z score of change of cognition was 0.20 (95% CI: 0.053, 0.35), with a Hedges' g of 0.40 (95% CI: 0.29, 0.50). However, this cognitive benefit was not significant at
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| 12. |
- Yang, Xinyi, et al.
(författare)
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Mechanisms underlying the responses of microbial carbon and nitrogen use efficiencies to nitrogen addition are mediated by topography in a subtropical forest
- 2023
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Ingår i: Science of the Total Environment. - 0048-9697. ; 880
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Tidskriftsartikel (refereegranskat)abstract
- Microbial carbon use efficiency (CUE) and nitrogen use efficiency (NUE) are key parameters determining the fate of C and N in soils. Atmospheric N deposition has been found to heavily impact multiple soil C and N transformations, but we lack understanding of the responses of CUE and NUE to N deposition, and it remains uncertain whether responses may be mediated by topography. Here, a N addition experiment with three treatment levels (0, 50 and 100 kg N ha−1 yr−1) was conducted in the valley and on the slope of a subtropical karst forest. Nitrogen addition increased microbial CUE and NUE at both topographic positions, but the underlying mechanisms differed. In the valley, the increase in CUE was associated with an increase in soil fungal richness:biomass and lower litter C:N, whereas on the slope, the response was linked with a reduced ratio of dissolved soil organic C (DOC) to available phosphorus (AVP) which reduced respiration, and increased root N:P stoichiometry. In the valley, the increase in NUE was explained by stimulated microbial N growth relative to gross N mineralization, which was associated with increased ratios of soil total dissolved N:AVP and fungal richness:biomass. In contrast, on the slope, the increase in NUE was attributed to reduced gross N mineralization, linked to increased DOC:AVP. Overall, our results highlight how topography-driven soil substrate availability and microbial properties can regulate microbial CUE and NUE.
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| 13. |
- Zhang, He, et al.
(författare)
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Decoding Fear : Exploring User Experiences in Virtual Reality Horror Games
- 2023
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Ingår i: Proceedings of the 11th International Symposium of Chinese CHI: Generative, Reflective, Envisioning, Chinese CHI 2023. - : Association for Computing Machinery (ACM). ; , s. 411-419
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Konferensbidrag (refereegranskat)abstract
- This preliminary study investigated user experiences in VR horror games, highlighting fear-triggering and gender-based differences in perception. By utilizing a scientifically validated and specially designed questionnaire, we successfully collected questionnaire data from 23 subjects for an early empirical study of fear induction in a virtual reality gaming environment. The early findings suggest that visual restrictions and ambient sound-enhanced realism may be more effective in intensifying the fear experience. Participants exhibited a tendency to avoid playing alone or during nighttime, underscoring the significant psychological impact of VR horror games. The study also revealed a distinct gender difference in fear perception, with female participants exhibiting a higher sensitivity to fear stimuli. However, the preference for different types of horror games was not solely dominated by males; it varied depending on factors such as the game's pace, its objectives, and the nature of the fear stimulant.
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| 14. |
- Zhang, He, et al.
(författare)
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VRMN-bD: A Multi-modal Natural Behavior Dataset of Immersive Human Fear Responses in VR Stand-up Interactive Games
- 2024
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Ingår i: Proceedings - 2024 IEEE Conference on Virtual Reality and 3D User Interfaces, VR 2024. - : Institute of Electrical and Electronics Engineers (IEEE). ; , s. 320-330
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Konferensbidrag (refereegranskat)abstract
- Understanding and recognizing emotions are important and challenging issues in the metaverse era. Understanding, identifying, and predicting fear, which is one of the fundamental human emotions, in virtual reality (VR) environments plays an essential role in immersive game development, scene development, and next-generation virtual human-computer interaction applications. In this article, we used VR horror games as a medium to analyze fear emotions by collecting multi-modal data (posture, audio, and physiological signals) from 23 players. We used an LSTM-based model to predict fear with accuracies of 65.31% and 90.47% under 6-level classification (no fear and five different levels of fear) and 2-level classification (no fear and fear), respectively. We constructed a multi-modal natural behavior dataset of immersive human fear responses (VRMN-bD) and compared it with existing relevant advanced datasets. The results show that our dataset has fewer limitations in terms of collection method, data scale and audience scope. We are unique and advanced in targeting multi-modal datasets of fear and behavior in VR stand-up interactive environments. Moreover, we discussed the implications of this work for communities and applications. The dataset and pre-trained model are available at https://github.com/KindOPSTAR/VRMN-bD.
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| 15. |
- Zhong, Jia, et al.
(författare)
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B vitamins attenuate the epigenetic effects of ambient fine particles in a pilot human intervention trial
- 2017
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 114:13, s. 3503-3508
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Tidskriftsartikel (refereegranskat)abstract
- Acute exposure to fine particle (PM2.5) induces DNA methylation changes implicated in inflammation and oxidative stress. We conducted a crossover trial to determine whether B-vitamin supplementation averts such changes. Ten healthy adults blindly received a 2-h, controlled-exposure experiment to sham under placebo, PM2.5 (250 μg/m(3)) under placebo, and PM2.5 (250 μg/m(3)) under B-vitamin supplementation (2.5 mg/d folic acid, 50 mg/d vitamin B6, and 1 mg/d vitamin B12), respectively. We profiled epigenome-wide methylation before and after each experiment using the Infinium HumanMethylation450 BeadChip in peripheral CD4(+) T-helper cells. PM2.5 induced methylation changes in genes involved in mitochondrial oxidative energy metabolism. B-vitamin supplementation prevented these changes. Likewise, PM2.5 depleted 11.1% [95% confidence interval (CI), 0.4%, 21.7%; P = 0.04] of mitochondrial DNA content compared with sham, and B-vitamin supplementation attenuated the PM2.5 effect by 102% (Pinteraction = 0.01). Our study indicates that individual-level prevention may be used to complement regulations and control potential mechanistic pathways underlying the adverse PM2.5 effects, with possible significant public health benefit in areas with frequent PM2.5 peaks.
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| 16. |
- Zhu, Xinyi, et al.
(författare)
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Leisure activities, education, and cognitive impairment in Chinese older adults : a population-based longitudinal study
- 2017
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Ingår i: International psychogeriatrics. - 1041-6102 .- 1741-203X. ; 29:5, s. 727-739
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Tidskriftsartikel (refereegranskat)abstract
- Background: We examine the association between leisure-time activities and the risk of developing cognitive impairment among Chinese older people, and further investigate whether the association varies by educational level. Methods: This follow-up study included 6,586 participants (aged 79.5 9.8 years, range 65-105 years, 51.7% female) of the Chinese Longitudinal Healthy Longevity Survey who were aged 65 years and were free of cognitive impairment in 2002. Incident cognitive impairment was defined at the 2005 or 2008/2009 survey following an education-based cut-off on the adapted Chinese version of Mini-Mental State Examination (MMSE). Participation in cognitive activities (e.g. reading) and non-exercise physical activity (e.g. housework) was assessed by a self-reported scale. Cox proportional hazard models were employed to examine the association of leisure activities with incident cognitive impairment while controlling for age, gender, education, occupation, residence, physical exercise, smoking, drinking, cardiovascular diseases and risk factors, negative well-being, and physical functioning, and baseline MMSE score. Results: During a five-year follow-up, 1,448 participants developed incident cognitive impairment. Overall, a high level of participation in leisure activities was associated with a 41% decreased risk of cognitive impairment compared to low-level engagement in leisure activities after controlling for age, gender, education, and other confounders. Moreover, there was a significant interaction between leisure activity and educational level, such that the beneficial effect of leisure activities on cognitive function was larger in educated elderly than their uneducated counterparts, and only educated elderly benefited from cognitive activities. Conclusions: Late-life leisure activities protect against cognitive impairment among elderly Chinese people, and the protective effects are more profound for educated elderly.
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