High-performance microwave-absorbing composites have attracted considerable attention in the field of electronic technology and telecommunications. These materials utilize stoichiometric combinations ...of components to enhance the magnetic parameters and reduce dielectric losses. In this work, microwave emulsion was used to synthesize magnetic nanocomposites with different concentrations of MgFe
2
O
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nanoparticles in polystyrene (PST). Samples of pure ferrite and PST were mixed in various amounts to form a ferrite polymer (FP-1, FP-2, FP-3, and FP-4, with 25%, 50%, 75%, and 100% ferrite, respectively). These composites were characterized using x-ray diffraction (XRD), dielectric characteristics, and vibrating-sample magnetometry (VSM). The XRD results showed that MgFe
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O
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particles were evenly dispersed throughout single-phase PST. The crystallite size increased from 2 nm to 44 nm by mixing ferrites in PST. The dielectric properties were reduced as the percentage was decreased. The VSM tests indicated that all nanocomposites showed narrow loops and ferromagnetic behavior. The magnetic parameters decreased by adding the PST in magnesium ferrite components. The saturation magnetization decreased from 70 emu/g to 18 emu/g, remanence magnetization decreased from 21 emu/g to 5 emu/g, and coercivity decreased from 38 Oe to 8 Oe. All the above parameter results suggest that due to the high dielectric loss at high frequencies, magnesium spinel ferrites may be suitable for microwave absorption applications.
OBJECTIVE—Cerebral vasoreactivity (CVR) is a key factor in maintenance of continuous cerebral perfusion and a marker of (micro)vascular damage. We aimed to determine the longitudinal relation between ...CVR and the risk of dementia in the general population.
APPROACH AND RESULTS—We determined CVR in nondemented participants who underwent transcranial Doppler with induced hypercapnia from 1997 to 1999, as part of the ongoing population-based Rotterdam Study. We used a Cox model to determine the risk of dementia in relation to CVR, adjusted for age, sex, cardiovascular risk factors, and carotid intima-media thickness. We furthermore determined decline on a cognitive test battery in relation to CVR, using linear mixed models. Among 1629 participants (mean±SD age 70.6±6.2 years, 46.2% female) with a mean follow-up of 11.5 years, 209 were diagnosed with dementia, of whom 171 had Alzheimer disease. Higher CVR at baseline was associated with lower risk of dementia (adjusted hazard ratio, 95% confidence interval, per SD increase0.87, 0.75–1.00) and Alzheimer disease (adjusted hazard ratio, 0.84; 0.71–0.99). This association was more profound in APOEε4 carriers than in noncarriers (adjusted hazard ratio for all dementia0.77, 0.60–0.98 versus 0.89, 0.73–1.07). Performance on cognitive tests at baseline was better with higher CVR (g-factorP=0.02), but during 3 cognitive assessments over 11 years of follow-up, higher CVR at baseline was associated with less decline in test scores on the Stroop reading and interference tasks in APOEε4 carriers only (P=0.01 and 0.02, respectively).
CONCLUSIONS—Impaired CVR is associated with an increased risk of dementia in the general population.
Cognitive and brain reserve refer to individual differences that allow some people to better withstand brain pathology than others. Although early life stress has been recognized as a risk factor for ...low reserve in late life, no research yet has studied this across midlife.
To examine the associations of life stress with brain and cognitive reserve in midlife.
We included 1,232 middle-aged women who participated in the ORACLE Study between 2002-2006). Life stress was calculated as the shared variance of four cumulative stress domains, created from items measured between pregnancy and 10 years after childbirth. Brain reserve was defined as healthy-appearing brain volume measured with MRI; cognitive reserve as better cognitive functioning than expected based on age, education, and brain MRI measures, using structural equation modelling.
More life stress was associated with lower brain (standardized adjusted difference: -0.18 95% CI 0.25,-0.12) and cognitive reserve (-0.19 -0.28,-0.10). Although, effect sizes were typically smaller, cumulative stress domains were also associated with brain reserve (life events: -0.10 -0.16,-0.04; contextual stress: -0.13 -0.19,-0.07; parenting-related stress: -0.13-0.19,-0.07; interpersonal stress: -0.10 -0.16,-0.04) and cognitive reserve (life events: -0.18 -0.25,-0.11; contextual stress: -0.15 -0.10,-0.02; parenting-related stress: -0.10 -0.18,-0.03; interpersonal stress not significant).
Women who experience more life stress in midlife were found to have lower reserve. Effects were primarily driven by shared variance across cumulative stress domains, suggesting that focusing on single domains may underestimate effects. The effect of life stress on lower reserve may make women with stress more prone to neurodegenerative disease later in life than women without stress.
Heat stress during grain filling is considered one of the major abiotic factors influencing wheat grain yield and quality in arid and semi-arid regions. We studied the effect of heat stress on flour ...quality and grain yield at moderate and continuous heat stress under natural field conditions using 147 lines of wheat multiple synthetic derivatives (MSD) containing Aegilops tauschii introgressions. The study aimed to identify the marker–trait associations (MTAs) for the quality traits and grain yield under heat-stress conditions and identify stress-resilient germplasm-combining traits for good flour quality and grain yield. The MSD lines showed considerable genetic variation for quality traits and grain yield under heat-stress conditions; some lines performed better than the recurrent parent, Norin 61. We identified two MSD lines that consistently maintained relative performance (RP) values above 100% for grain yield and dough strength. We found the presence of three high-molecular-weight glutenin subunits (HMW-GSs) at the Glu-D1 locus derived from Ae. tauschii, which were associated with stable dough strength across the four environments used in this study. These HMW-GSs could be potentially useful in applications for future improvements of end-use quality traits targeting wheat under severe heat stress. A total of 19,155 high-quality SNP markers were used for the genome-wide association analysis and 251 MTAs were identified, most of them on the D genome, confirming the power of the MSD panel as a platform for mining and exploring the genes of Ae. tauschii. We identified the MTAs for dough strength under heat stress, which simultaneously control grain yield and relative performance for dough strength under heat-stress/optimum conditions. This study proved that Ae. tauschii is an inexhaustible resource for genetic mining, and the identified lines and pleiotropic MTAs reported in this study are considered a good resource for the development of resilient wheat cultivars that combine both good flour quality and grain yield under stress conditions using marker-assisted selection.
Refractive errors are the most common ocular disorders worldwide and may lead to blindness. Although this trait is highly heritable, identification of susceptibility genes has been challenging. We ...conducted a genome-wide association study for refractive error in 5,328 individuals from a Dutch population-based study with replication in four independent cohorts (combined 10,280 individuals in the replication stage). We identified a significant association at chromosome 15q14 (rs634990, P = 2.21 × 10−14). The odds ratio of myopia compared to hyperopia for the minor allele (minor allele frequency = 0.47) was 1.41 (95% CI 1.16-1.70) for individuals heterozygous for the allele and 1.83 (95% CI 1.42-2.36) for individuals homozygous for the allele. The associated locus is near two genes that are expressed in the retina, GJD2 and ACTC1, and appears to harbor regulatory elements which may influence transcription of these genes. Our data suggest that common variants at 15q14 influence susceptibility for refractive errors in the general population.
Several psychosocial risk factors for complicated grief have been described. However, the association of complicated grief with cognitive and biological risk factors is unclear. The present study ...examined whether complicated grief and normal grief are related to cognitive performance or structural brain volumes in a large population-based study.
The present research comprised cross-sectional analyses embedded in the Rotterdam Study. The study included 5501 non-demented persons. Participants were classified as experiencing no grief (n = 4731), normal grief (n = 615) or complicated grief (n = 155) as assessed with the Inventory of Complicated Grief. All persons underwent cognitive testing (Mini-Mental State Examination, Letter-Digit Substitution Test, Stroop Test, Word Fluency Task, word learning test - immediate and delayed recall), and magnetic resonance imaging to measure general brain parameters (white matter, gray matter), and white matter lesions. Total brain volume was defined as the sum of gray matter plus normal white matter and white matter lesion volume. Persons with depressive disorders were excluded and analyses were adjusted for depressive symptoms.
Compared with no-grief participants, participants with complicated grief had lower scores for the Letter-Digit Substitution Test Z-score -0.16 v. 0.04, 95% confidence interval (CI) -0.36 to -0.04, p = 0.01 and Word Fluency Task (Z-score -0.15 v. 0.03, 95% CI -0.35 to -0.02, p = 0.02) and smaller total volumes of brain matter (933.53 ml v. 952.42 ml, 95% CI -37.6 to -0.10, p = 0.04).
Participants with complicated grief performed poorly in cognitive tests and had a smaller total brain volume. Although the effect sizes were small, these findings suggest that there may be a neurological correlate of complicated grief, but not of normal grief, in the general population.
The goal of this paper is to increase the statistical power of crossing-fiber statistics in voxelwise analyses of diffusion-weighted magnetic resonance imaging (DW-MRI) data. In the proposed ...framework, a fiber orientation atlas and a model complexity atlas were used to fit the ball-and-sticks model to diffusion-weighted images of subjects in a prospective population-based cohort study. Reproducibility and sensitivity of the partial volume fractions in the ball-and-sticks model were analyzed using TBSS (tract-based spatial statistics) and compared to a reference framework. The reproducibility was investigated on two scans of 30 subjects acquired with an interval of approximately three weeks by studying the intraclass correlation coefficient (ICC). The sensitivity to true biological effects was evaluated by studying the regression with age on 500 subjects from 65 to 90 years old. Compared to the reference framework, the ICC improved significantly when using the proposed framework. Higher t-statistics indicated that regression coefficients with age could be determined more precisely with the proposed framework and more voxels correlated significantly with age. The application of a fiber orientation atlas and a model complexity atlas can significantly improve the reproducibility and sensitivity of crossing-fiber statistics in TBSS.
Objective
To investigate whether child mental health problems prospectively associate with IQ‐achievement discrepancy (i.e., academic under‐ and over‐achievement) in emerging adolescence. The ...secondary aims were to test whether these associations are specific to certain mental health problems, to assess potential sex differences, and to examine whether associations are robustly observed across multiple informants (i.e., maternal and teacher‐reports).
Methods
This study included 1,577 children from the population‐based birth cohort the Generation R Study. Child mental health problems at age 6 were assessed by mothers and teachers using the Child Behavior Checklist and the Teacher's Report Form. The IQ‐achievement discrepancy was quantified as the standardized residuals of academic achievement regressed on IQ, where IQ was measured with four tasks from the Wechsler Intelligence Scale for Children‐Fifth Edition around age 13 and academic attainment was measured with the Cito test, a national Dutch academic test, at the end of elementary school (12 years of age).
Results
Mental health problems at age 6 were associated with IQ‐achievement discrepancy at age 12, with more problems associating with greater academic underachievement. When examining specific mental health problems, we found that attention problems was the only mental health problem to independently associate with the IQ‐achievement discrepancy (adjusted standardized difference per 1‐standard deviation, mother: −0.11, p < 0.001, 95% CI −0.16, −0.06; teacher: −0.13, p < 0.001, 95% CI −0.18, −0.08). These associations remained after adjusting for co‐occurring mental health problems. The overall pattern of associations was consistent across boys and girls and across informants.
Conclusion
Mental health problems during the transition from kindergarten to elementary school associate with academic underachievement at the end of elementary school. These associations were primarily driven by attention problems, as rated by both mothers and teachers—suggesting that strategies targeting attention problems may be a particularly promising avenue for improving educational performance irrespective of IQ, although this should be established more thoroughly through further research.
Background. The COVID-19 pandemic has presented an unprecedented strain on healthcare supplies. Currently there is a global shortage of personal protective equipment (PPE), especially N95 masks. In ...order to safeguard healthcare personnel in this critical time and to mitigate shortages of N95 respirators, reuse of N95 respirators has to be considered. Methods. Using PubMed and Science Direct, a literature search was conducted to find and synthesize relevant literature on decontamination of N95 respirators for their subsequent reuse. Peer-reviewed publications related to methods of decontamination from January 2007 to April 2020 in the English language are included in this narrative review. Bibliographies of articles for relevant literature were also scrutinized. Findings. A total of 19 studies are included in this narrative review. The appraised methods include ultraviolet germicidal irradiation (UVGI), moist heat incubation (MHI), ethylene oxide (EtO), hydrogen peroxide vapor (HPV), microwave steam bags (MSB), microwave-generated steam (MGS), dry microwave oven irradiation, hydrogen peroxide gas plasma (HPGP), dry heat, liquid hydrogen peroxide, and bleach and alcohol. Conclusion. In light of the COVID-19 pandemic, reuse of N95 respirators, although suboptimal, can be considered. Evidence reveals that UVGI, MHI, and HPV are amongst the safest and efficacious methods for decontamination of N95 masks. More research is needed to establish the safety and effectiveness of MGS, MSB, dry heat, EtO, liquid hydrogen peroxide, and HPGP. Alcohol, microwave irradiation, and bleach are not recommended because they damage N95 respirators.
Energy security is the foremost concern for a sustainable environment. To make a sustainable environment, biomass waste products like biomass oil and biofuels must be efficiently burned. As millions ...of tons of waste biomass are dumped daily in major cities worldwide, it must be brought into energy products utilization. The quest for a sustainable ecosystem has pushed scientists to explore alternative fuels that are not only compatible with the engine but also eco-friendly. Hydrogen exhibits excellent combustion characteristics during dual fuel mode in a compression ignition (CI) engine. Carbon dioxide and NOx emissions are the two significant pollutants alternative fuels produce. This review study has tried to mitigate these two pollutants by combining biodiesel and hydrogen. It has been investigated that hydrogen possesses zero carbon content and can reduce CO2 emission, and biodiesel made from algae resources can help reduce NOx emission. Therefore, it is highlighted through the current review study to use the blend of hydrogen and algae-based biodiesel fuels to achieve benefits from their combined physicochemical properties and mitigate greenhouse gas emissions. The carbon-free nature of hydrogen and the oxygenated nature of biodiesel can be an excellent combination for combustion in diesel engines. Adopting third-generation fuels such as algae appears to be a viable solution to meet future energy demands. Biodiesel has a lower calorific value and viscous nature, negatively impacting fuel spray characteristics and creating abrupt fuel consumption. The purpose of this study is to promote biomass oil burning using hydrogen as a promoter supplement blend. Hydrogen has a higher heating value that can help overcome the less heating value of biodiesel fuels. Therefore, hydrogen as a blend with biodiesel makes the mixture lean and positively impacts engine performance, emissions, and combustion parameters.
•Recent progress in hydrogen-blended biomass fuels to reduce GHGs.•Applications of hydrogen-piloted biofuel.•Impact of hydrogen blended biomass fuels on engine performance.•SWOT analysis and lifecycle assessment to check the applicability as a fuel.•Technical challenges, research opportunities, and future outlook.
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