Real diesel engine exhaust emission control: indirect non-thermal plasma and comparison to direct plasma for NOX, THC, CO, and CO2

Recently, diesel engine exhaust emission control by non-thermal plasma (NTP) technology has been shown to be promising. However, carbon and soot deposition on the inner surface of the NTP reactor for direct plasma processing decreased the efficiency of the plasma process throughout the experiments. In the present work, the feasibility of indirect plasma processing was investigated as an innovative and novel method compared to direct plasma processing. Air was directed through an NTP at an applied voltage of VP-P  = 7 kV and a flow rate of 1-4 L/min, and then, it was combined with engine exhaust gas at a flow rate of 5 L/min. In this case, the maximum conversion of NOX was 64.9% at 4 L/min. However, for direct plasma processing at 5 L/min, NO conversion was 58%, which proves that the indirect NTP process can decrease NOX concentration effectively. The maximum conversion for unburned hydrocarbon (UHC), carbon monoxide (CO) and carbon dioxide (CO2) was obtained as 2%, 4% and 0.7% at 4, 2 and 3 L/min in indirect plasma processing; While their remove rate for direct plasma processing was 16.3%, -0.5% and 13.2%, respectively.

CO2 Hydrogenation at Atmospheric Pressure and Low Temperature Using Plasma-Enhanced Catalysis over Supported Cobalt Oxide Catalysts

CO₂ is a promising renewable, cheap, and abundant C1 feedstock for producing valuable chemicals, such as CO and methanol. In conventional reactors, because of thermodynamic constraints, converting CO₂ to methanol requires high temperature and pressure, typically 250 °C and 20 bar. Nonthermal plasma is a better option, as it can convert CO₂ at near-ambient temperature and pressure. Adding a catalyst to such plasma setups can enhance conversion and selectivity. However, we know little about the effects of catalysts in such systems. Here, we study CO₂ hydrogenation in a dielectric barrier discharge plasma-catalysis setup under ambient conditions using MgO, γ-Al₂O₃, and a series of Co _x O _y /MgO catalysts. While all three catalyst types enhanced CO₂ conversion, Co _x O _y /MgO gave the best results, converting up to 35% of CO₂ and reaching the highest methanol yield (10%). Control experiments showed that the basic MgO support is more active than the acidic γ-Al₂O₃, and that MgO-supported cobalt oxide catalysts improve the selectivity toward methanol. The methanol yield can be tuned by changing the metal loading. Overall, our study shows the utility of plasma catalysis for CO₂ conversion under mild conditions, with the potential to reduce the energy footprint of CO₂-recycling processes.

Plasma-enhanced direct conversion of CO2 to CO over oxygen-deficient Mo-doped CeO2

Plasma CO2 splitting to CO over oxygen-deficient Mo-doped CeO2 under mild conditions was investigated for the first time, showing ∼20 times higher CO2 conversion compared to pure CeO2, which can be attributed to the increased oxygen vacancies (VO) and the formation of Ce3+-VO-Mo on the catalyst surface. Importantly, VO sites showed excellent catalytic stability.

Predictors of Loneliness by Age Decade: Study of Psychological and Environmental Factors in 2,843 Community-Dwelling Americans Aged 20-69 Years

OBJECTIVE

Loneliness is a prevalent and serious public health problem due to its effects on health, well-being, and longevity. Understanding correlates of loneliness is critical for guiding efforts toward the development of evidence-based strategies for prevention and intervention. Considering that patterns of association between age and loneliness vary, the present study sought to examine age-related differences in risk and protective factors for loneliness.

METHODS

Correlates of loneliness were examined through a large web-based survey of 2,843 participants (aged 20-69 years) from across the United States from April 10, 2019, through May 10, 2019. Participants completed the 4-item UCLA Loneliness Scale, San Diego Wisdom Scale (with the following subscales measuring components of wisdom: Prosocial Behaviors, Emotional Regulation, Self-Reflection, Acceptance of Divergent Values, Decisiveness, and Social Advising), and other scales measuring psychosocial variables. Multivariate regression analyses were conducted to identify the best model of loneliness and examine potential age-related differences.

RESULTS

Age demonstrated a nonlinear quadratic relationship with loneliness (Wald statistic = 5.48, P = .019); levels were highest in the 20s and lowest in the 60s with another peak in the mid-40s. Across all decades, loneliness was associated with not having a spouse or partner (P < .001), sleep disturbance (P < .02), lower prosocial behaviors (P < .001), and smaller social network (P < .001). Lower social self-efficacy (P < .001) and higher anxiety (P < .005) were associated with worse loneliness in all age decades, except the 60s. Loneliness was uniquely associated with decisiveness in the 50s (P = .012) and with education (P = .046) and memory complaints (P = .013) in the 60s.

CONCLUSIONS

Our findings identify several potentially modifiable targets related to loneliness, including several aspects of wisdom and social self-efficacy. Differential predictors at different decades suggest a need for a personalized and nuanced prioritizing of prevention and intervention targets.

Effect of gabapentin on hyperemesis gravidarum: a double-blind, randomized controlled trial

BACKGROUND

Hyperemesis gravidarum is a disabling disease of nausea, vomiting, and undernutrition in early pregnancy for which there are no effective outpatient therapies. Poor weight gain in hyperemesis gravidarum is associated with several adverse fetal outcomes including preterm delivery, low birthweight, small for gestational age, low 5-minute Apgar scores, and neurodevelopmental delay. Gabapentin is most commonly used clinically for treating neuropathic pain but also substantially reduces chemotherapy-induced and postoperative nausea and vomiting. Pregnancy registry data have shown maternal first-trimester gabapentin monotherapy to be associated with a 1.2% rate of major congenital malformations among 659 infants, which compares favorably with the 1.6% to 2.2% major congenital malformation rate in the general population. Open-label gabapentin treatment in hyperemesis gravidarum was associated with reduced nausea and vomiting and improved oral nutrition.

OBJECTIVE

This study aimed to determine whether gabapentin is more effective than standard-of-care therapy for treating hyperemesis gravidarum.

STUDY DESIGN

A double-blind, randomized, multicenter trial was conducted among patients with medically refractory hyperemesis gravidarum requiring intravenous hydration. Patients were randomized (1:1) to either oral gabapentin (1800-2400 mg/d) or an active comparator of either oral ondansetron (24-32 mg/d) or oral metoclopramide (45-60 mg/d) for 7 days. Differences in Motherisk-pregnancy-unique quantification of nausea and emesis total scores between treatment groups averaged over days 5 to 7, using intention-to-treat principle employing a linear mixed-effects model adjusted for baseline Motherisk-pregnancy-unique quantification of nausea and emesis scores, which served as the primary endpoint. Secondary outcomes included Motherisk-pregnancy-unique quantification of nausea and emesis nausea and vomit and retch subscores, oral nutrition, global satisfaction of treatment, relief, desire to continue therapy, Nausea and Vomiting of Pregnancy Quality of Life, and Hyperemesis Gravidarum Pregnancy Termination Consideration. Adjustments for multiple comparisons were made employing the false discovery rate.

RESULTS

A total of 31 patients with hyperemesis gravidarum were enrolled from October 2014 to May 2019. Among the 21 patients providing primary outcome data (12 assigned to gabapentin and 9 to the active comparator arm), 18 were enrolled as outpatients and all 21 were outpatients from days 5 to 7. The study groups' baseline characteristics were well matched. Gabapentin treatment provided a 52% greater reduction in days 5 to 7 baseline adjusted Motherisk-pregnancy-unique quantification of nausea and emesis total scores than treatment with active comparator (95% confidence interval, 16-88; P=.01). Most secondary outcomes also favored gabapentin over active comparator treatment including 46% and 49% decreases in baseline adjusted Motherisk-pregnancy-unique quantification of nausea and emesis nausea (95% confidence interval, 19-72; P=.005) and vomit and retch subscores (95% confidence interval, 21-77; P=.005), respectively; a 96% increase in baseline adjusted oral nutrition scores (95% confidence interval, 27-165; P=.01); and a 254% difference in global satisfaction of treatment (95% confidence interval, 48-459; P=.03). Relief (P=.06) and desire to continue therapy (P=.06) both showed trends favoring gabapentin treatment but Nausea and Vomiting of Pregnancy Quality of Life (P=.68) and Hyperemesis Gravidarum Pregnancy Termination Consideration (P=.58) did not. Adverse events were roughly equivalent between the groups. There were no serious adverse events.

CONCLUSION

In this small trial, gabapentin was more effective than standard-of-care therapy for reducing nausea and vomiting and increasing oral nutrition and global satisfaction in outpatients with hyperemesis gravidarum. These data build on previous findings in other patient populations supporting gabapentin as a novel antinausea and antiemetic therapy and support further research on gabapentin for this challenging complication of pregnancy.

Tributyltin enhanced anxiety of adult male zebrafish through elevating cortisol level and disruption in serotonin, dopamine and gamma-aminobutyric acid neurotransmitter pathways

Tributyltin (TBT), a widely and persistently distributed organontin, has been well documented to disrupt reproduction and behaviors in animals due to its anti-aromatase activity. TBT has been also reported to enhance anxiety in several fish species, whereas the mechanism underlying remains largely unknown. To investigate the disruption of TBT on fish anxiety and the mechanisms possibly involved, adult male zebrafish (Danio rerio) were treated with TBT (100 and 500 ng/L) for 28 days and anxiety behavior was further investigated using a novel tank dive test. Result showed that TBT treatment significantly enhanced the total time of the fish spent in the lower half, delayed the onset time to the higher half of the tank and increased the total duration of freezing of the fish, indicating an enhanced anxiety in TBT-treated fish. Accordingly, TBT sharply elevated the cortisol levels in plasma in a concentration-dependent manner, suggesting that the elevated cortisol level might be involved in the enhanced anxiety. Although the expression of crha was significantly increased and crhbp was significantly decreased in the brain of TBT-treated fish which is consistent to the elevated cortisol level, the expressions of actha and acthb were sharply down-regulated. In contrast, the expressions of genes responsible for the synthesis and action of serotonin (5-HT) (pet1, thp2 and htr1aa), dopamine (DA) (th1, slc6a3, drd2a and drd2b) and gamma-aminobutyric acid (GABA) (gad2 and gabrg2) were all significantly inhibited. The down-regulation of these pivotal genes acting in 5-HT, DA and GABA neurotransmitter systems in response to TBT corresponded well with the TBT-enhanced anxiety in fish. It was thus strongly suggested that these neurotransmitters might be also involved in TBT-enhanced anxiety in adult male zebrafish. The present study extended our understanding of the neurotoxicity of TBT on the anxiety control and behavioral modulation in fish.

A compact and polarization-insensitive silicon waveguide crossing based on subwavelength grating MMI couplers

In this work, we proposed and experimentally demonstrated a compact and low polarization-dependent silicon waveguide crossing based on subwavelength grating multimode interference couplers. The subwavelength grating structure decreases the effective refractive index difference and shrinks the device footprint. Our designed device is fabricated on the 220-nm SOI platform and performs well. The measured crossing is characterized with low insertion loss (< 1 dB), low polarization-dependence loss (< 0.6 dB), and low crosstalk (< -35 dB) for both TE and TM polarizations with a compact footprint of 12.5 μm × 12.5 μm.

Integrated gasification and non-thermal plasma-catalysis system for cleaner syngas production from cellulose

An innovative integrated gasification and plasma-catalytic system has been developed to produce cleaner syngas from a model biofeedstock (α-cellulose). The influence of Co/γ-Al2O3 catalyst on the plasma reforming of tar-contaminated syngas has been investigated using a cylindrical dielectric barrier discharge reactor. The results show that plasma-catalytic processing of the syngas from biomass gasification significantly reduces the concentration of tars by 88% and enhances the total gas product yield and the syngas ratio (H2/CO) by up to 90%.

Posttraumatic stress symptom persistence across 24 years: association with brain structures

Posttraumatic stress disorder (PTSD) is known to persist, eliciting early medical co-morbidity, and accelerated aging. Although PTSD diagnosis has been found to be associated with smaller volume in multiple brain regions, posttraumatic stress (PTS) symptoms and their associations with brain morphometry are rarely assessed over long periods of time. We predicted that persistent PTS symptoms across ~24 years would be inversely associated with hippocampal, amygdala, anterior cingulate volumes, and hippocampal occupancy (HOC = hippocampal volume/[hippocampal volume + inferior lateral ventricle volume]) in late middle age. Exploratory analyses examined prefrontal regions. We assessed PTS symptoms in 247 men at average ages 38 (time 1) and 62 (time 2). All were trauma-exposed prior to time 1. Brain volumes were assessed at time 2 using 3 T structural magnetic resonance imaging. Symptoms were correlated over time (r = 0.46 p < .0001). Higher PTS symptoms averaged over time and symptoms at time 1 were both associated with lower hippocampal, amygdala, rostral middle frontal gyrus (MFG), and medial orbitofrontal cortex (OFC) volumes, and a lower HOC ratio at time 2. Increased PTS symptomatology from time 1 to time 2 was associated with smaller hippocampal volume. Results for hippocampal, rostral MFG and medial OFC remained significant after omitting individuals above the threshold for PTSD diagnosis. Even at sub-diagnostic threshold levels, PTS symptoms were present decades after trauma exposure in parallel with highly correlated structural deficits in brain regions regulating stress responsivity and adaptation.

Predicting Health-Related Quality of Life in Trauma-Exposed Male Veterans in Late Midlife: A 20 Year Longitudinal Study

Trauma-exposed adults with high levels of posttraumatic stress symptoms (PTSS) report poorer health-related quality of life (HRQOL), but less is known about the persistence of this relationship over time. Participants from the Vietnam Era Twin Study of Aging reported on PTSS, health, and sociodemographic characteristics at average age 38; 775 participants reported having been exposed to trauma. Later, at average ages 56 and 62, mental and physical HRQOL were assessed with the Short-Form 36. Premorbid risk for anxiety/neuroticism was evaluated with a polygenic risk score derived from a large genome-wide association study meta-analysis. In multivariate mixed models, having higher levels of PTSS, poorer self-rated health, lower income, and less education at age 38 were associated with worse physical and mental HRQOL two decades later. Chronic health problems at age 38 predicted midlife physical but not mental HRQOL. Although genetic risk for neuroticism was correlated with HRQOL and PTSS, it was no longer significant in multivariate models. Health-related quality of life (HRQOL) predicts morbidity and mortality independently of objective health measures; early interventions may help to mitigate the ongoing impact of trauma on quality of life.

Genetic Underpinnings of Increased BMI and Its Association With Late Midlife Cognitive Abilities

Objectives: First, we test for differences in various cognitive abilities across trajectories of body mass index (BMI) over the later life course. Second, we examine whether genetic risk factors for unhealthy BMIs—assessed via polygenic risk scores (PRS)—predict cognitive abilities in late-life. Methods: The study used a longitudinal sample of Vietnam veteran males to explore the associations between BMI trajectories, measured across four time points, and later cognitive abilities. The sample of 977 individuals was drawn from the Vietnam Era Twin Study of Aging. Cognitive abilities evaluated included executive function, abstract reasoning, episodic memory, processing speed, verbal fluency, and visual spatial ability. Multilevel linear regression models were used to estimate the associations between BMI trajectories and cognitive abilities. Then, BMI PRS was added to the models to evaluate polygenic associations with cognitive abilities. Results: There were no significant differences in cognitive ability between any of the BMI trajectory groups. There was a significant inverse relationship between BMI-PRS and several cognitive ability measures. Discussion: While no associations emerged for BMI trajectories and cognitive abilities at the phenotypic levels, BMI PRS measures did correlate with key cognitive domains. Our results suggest possible polygenic linkages cutting across key components of the central and peripheral nervous system.

Cloaking object on an optofluidic chip: its theory and demonstration

Recently, the design of metamaterial guided by transformation optics (TO) has emerged as an effective method to hide objects from optical detection, based on arranging a bended light beam to detour. However, this TO-based solution involves fabrication of material with complicated distribution of permittivity and permeability, and the device falls short of tunability after fabrication. In this work, we propose an optofluidic model employing the method of streamline tracing-based transformation optofluidics (STTOF) to hydrodynamically reconfigure light propagation in a given flow field for object-cloaking purposes. The proof-of-concept is demonstrated and tested on an optofluidic chip to validate our proposed theory. Experimental results show that our proposed STTOF method can be used to successfully detour the light path from the object under cloaking in a mathematically pre-defined manner.

ADTRP regulates TFPI expression via transcription factor POU1F1 involved in coronary artery disease

Genomic variants in both ADTRP and TFPI genes are associated with risk of coronary artery disease (CAD). ADTRP regulates TFPI expression and endothelial cell functions involved in the initiation of atherosclerotic CAD. ADTRP also specifies primitive myelopoiesis and definitive hematopoiesis by upregulating TFPI expression. However, the underlying molecular mechanism is unknown. Here we show that transcription factor POU1F1 is the key by which ADTRP regulates TFPI expression. Luciferase reporter assays, chromatin-immunoprecipitation (ChIP) and electrophoretic mobility shift assay (EMSA) in combination with analysis of large and small deletions of the TFPI promoter/regulatory region were used to identify the molecular mechanism by which ADTRP regulates TFPI expression. Genetic association was assessed using case-control association analysis and phenome-wide association analysis (PhenGWA). ADTRP regulates TFPI expression at the transcription level in a dose-dependent manner. The ADTRP-response element was localized to a 50 bp region between -806 bp and -756 bp upstream of TFPI transcription start site, which contains a binding site for POU1F1. Deletion of POU1F1-binding site or knockdown of POU1F1 expression abolished ADTRP-mediated transcription of TFPI. ChIP and EMSA demonstrated that POU1F1 binds to the ADTRP response element. Genetic analysis identified significant association between POU1F1 variants and risk of CAD. PhenGWA identified other phenotypic traits associated with the ADTRP-POU1F1-TFPI axis such as lymphocyte count (ADTRP), waist circumference (TFPI), and standing height (POU1F1). These data identify POU1F1 as a transcription factor that regulates TFPI transcription in response to ADTRP, and link POU1F1 variants to risk of CAD for the first time.

Solar-Enhanced Plasma-Catalytic Oxidation of Toluene over a Bifunctional Graphene Fin Foam Decorated with Nanofin-like MnO2

In this work, we propose a hybrid and unique process combining solar irradiation and post-plasma catalysis (PPC) for the effective oxidation of toluene over a highly active and stable MnO₂/GFF (bifunctional graphene fin foam) catalyst. The bifunctional GFF, serving as both the catalyst support and light absorber, is decorated with MnO₂ nanofins, forming a hierarchical fin-on-fin structure. The results show that the MnO₂/GFF catalyst can effectively capture and convert renewable solar energy into heat (absorption of >95%), leading to a temperature rise (55.6 °C) of the catalyst bed under solar irradiation (1 sun, light intensity 1000 W m^-2). The catalyst weight (9.8 mg) used in this work was significantly lower (10-100 times lower) than that used in previous studies (usually 100-1000 mg). Introducing solar energy into the typical PPC process via solar thermal conversion significantly enhances the conversion of toluene and CO₂ selectivity by 36-63%, reaching ∼93% for toluene conversion and ∼83% for CO₂ selectivity at a specific input energy of ∼350 J L^-1, thus remarkably reducing the energy consumption of the plasma-catalytic gas cleaning process. The energy efficiency for toluene conversion in the solar-enhanced post-plasma catalytic (SEPPC) process reaches up to 12.7 g kWh^-1, ∼57% higher than that using the PPC process without solar irradiation (8.1 g kWh^-1), whereas the energy consumption of the SEPPC process is reduced by 35-52%. Moreover, the MnO₂/GFF catalyst exhibits an excellent self-cleaning capability induced by solar irradiation, demonstrating a superior long-term catalytic stability of 72 h at 1 sun, significantly better than that reported in previous works. The prominent synergistic effect of solar irradiation and PPC with a synergistic capacity of ∼42% can be mainly attributed to the solar-induced thermal effect on the catalyst bed, boosting ozone decomposition (an almost triple enhancement from ∼0.18 g_O3 g^-1 h^-1 for PPC to ∼0.52 g_O3 g^-1 h^-1 for SEPPC) to generate more oxidative species (e.g., O radicals) and enhancing the catalytic oxidation on the catalyst surfaces, as well as the self-cleaning capacity of the catalyst at elevated temperatures driven by solar irradiation. This work opens a rational route to use abundant, renewable solar power to achieve high-performance and energy-efficient removal of volatile organic compounds.

Design of an arbitrary ratio optical power splitter based on a discrete differential multiobjective evolutionary algorithm

Traditional photonic integrated devices are designed to predict their optical response by transforming the structure and parameters, and it is often difficult to obtain devices with excellent performance in all aspects. The nanophotonic computing design method based on the optimization algorithm has revolutionized the traditional photonic integrated device design technology. Here, we report a discrete differential evolution algorithm that simulates a natural selection process to achieve an ultracompact arbitrary power ratio splitter. The footprint of the designed splitter is only ${2.5}\;\unicode{x00B5} {\rm m} \times {2}.{5}\;\unicode{x00B5} {\rm m}$2.5µm×2.5µm, the simulated total transmission efficiency is above 90%, the power ratio error is less than 3%, and it can work normally over the C-band. Our algorithm can provide new ideas for the application of genetic algorithms to the automatic optimization of photonic integrated devices.

Attitude Toward Own Aging Among Older Adults: Implications for Cancer Prevention

BACKGROUND AND OBJECTIVES

Negative age stereotypes can become internalized and contribute to lower levels of physical and mental well-being in older adults, including those with serious illnesses. The main objective of this study was to examine the relationships of attitude toward own aging (ATOA) with health outcomes after controlling for resilience among older cancer survivors and comparison subjects without cancer, aged 50 years or older.

METHODS

We examined data in 1,140 adults from the Successful Aging Evaluation (SAGE) study, a structured multi-cohort investigation of community-based adults selected using random digit dialing. There were 219 participants with cancer (excluding skin cancer) and 912 without cancer. ATOA was assessed with the Philadelphia Geriatric Morale Scale, and its relationship with measures of physical, cognitive, and mental health, as well as resilience was evaluated.

RESULTS

Individuals with cancer reported slightly more pessimistic ATOA than individuals without cancer. ATOA correlated with physical and mental health in individuals with and without cancer. Hierarchical linear multiple regression revealed that ATOA contributed significantly to the prediction of physical and mental health after controlling for socio-demographic variables and resilience.

DISCUSSION AND IMPLICATIONS

Higher levels of positive ATOA appear to be a protective factor for health in older adults, including those with cancer. Interventions that provide education about positive aspects of aging, modify negative automatic thoughts, and promote optimism may be useful for increasing ATOA and thereby improving physical and mental health in older adults, especially those with cancer.

Tackling environmental challenges in pollution controls using artificial intelligence: A review

This review presents the developments in artificial intelligence technologies for environmental pollution controls. A number of AI approaches, which start with the reliable mapping of nonlinear behavior between inputs and outputs in chemical and biological processes in terms of prediction models to the emerging optimization and control algorithms that study the pollutants removal processes and intelligent control systems, have been developed for environmental clean-ups. The characteristics, advantages and limitations of AI methods, including single and hybrid AI methods, were overviewed. Hybrid AI methods exhibited synergistic effects, but with computational heaviness. The up-to-date review summarizes i) Various artificial neural networks employed in wastewater degradation process for the prediction of removal efficiency of pollutants and the search of optimizing experimental conditions; ii) Evaluation of fuzzy logic used for intelligent control of aerobic stage of wastewater treatment process; iii) AI-aided soft-sensors for precisely on-line/off-line estimation of hard-to-measure parameters in wastewater treatment plants; iv) Single and hybrid AI methods applied to estimate pollutants concentrations and design monitoring and early-warning systems for both aquatic and atmospheric environments; v) AI modelings of short-term, mid-term and long-term solid waste generations, and various ANNs for solid waste recycling and reduction. Finally, the future challenges of AI-based models employed in the environmental fields are discussed and proposed.

Dehydrogenation of formic acid over Pd/C catalysts: insight into the cold plasma treatment

Non-thermal plasma treatment has great potential to open a fast and green route for controllable synthesis of highly active supported metal catalysts.

Meaning in Life and Its Relationship With Physical, Mental, and Cognitive Functioning: A Study of 1,042 Community-Dwelling Adults Across the Lifespan

OBJECTIVE

To examine the relationship of presence and search for meaning in life with age, physical and mental well-being, and cognitive functioning across the adult lifespan.

METHODS

Cross-sectional data from 1,042 adults in the Successful AGing Evaluation (SAGE)-a multicohort study of adult community-dwelling residents of San Diego County, California-were analyzed. Presence of meaning ("Presence") and search for meaning in life ("Search") were assessed with the Meaning in Life Questionnaire. Physical and mental well-being were measured using the Short Form 36 Health Survey (SF-36). Telephone Interview for Cognitive Status-modified was employed to screen for overall cognitive function. Study data were collected from January 2013 to June 2014.

RESULTS

Presence of meaning exhibited an inverted U-shaped relationship whereas Search showed a U-shaped relationship with age (with Presence peaking and Search reaching the lowest point around age 60). Statistical modeling using generalized estimating equations revealed that physical well-being (SF-36 physical composite score) correlated negatively with age (P < .001) and positively with Presence (P < .001), and there was an age group x Presence interaction (P = .018), such that the relationship was stronger in subjects over age 60. Mental well-being correlated positively with age (P < .001) and Presence (P < .001) and negatively with Search (P = .002). Cognitive function correlated inversely with age (P < .001) and with Search (P < .001). Significant covariates of Presence and Search had small effect sizes, except for a medium effect size for satisfaction with life and Presence in adults over age 60 (P < .001).

CONCLUSIONS

Presence and search for meaning in life are important for health and well-being, though the relationships differ in adults younger and older than 60 years. Better understanding of the longitudinal relationships of meaning of life with well-being is warranted to design interventions to increase meaning of life and improve health and functioning.

Plasma-Enhanced Catalytic Synthesis of Ammonia over a Ni/Al2O3 Catalyst at Near-Room Temperature: Insights into the Importance of the Catalyst Surface on the Reaction Mechanism

A better fundamental understanding of the plasma-catalyst interaction and the reaction mechanism is vital for optimizing the design of catalysts for ammonia synthesis by plasma-catalysis. In this work, we report on a hybrid plasma-enhanced catalytic process for the synthesis of ammonia directly from N₂ and H₂ over transition metal catalysts (M/Al₂O₃, M = Fe, Ni, Cu) at near room temperature (∼35 °C) and atmospheric pressure. Reactions were conducted in a specially designed coaxial dielectric barrier discharge (DBD) plasma reactor using water as a ground electrode, which could cool and maintain the reaction at near-room temperature. The transparency of the water electrode enabled operando optical diagnostics (intensified charge-coupled device (ICCD) imaging and optical emission spectroscopy) of the full plasma discharge area to be conducted without altering the operation of the reactor, as is often needed when using coaxial reactors with opaque ground electrodes. Compared to plasma synthesis of NH₃ without a catalyst, plasma-catalysis significantly enhanced the NH₃ synthesis rate and energy efficiency. The effect of different transition metal catalysts on the physical properties of the discharge is negligible, which suggests that the catalytic effects provided by the chemistry of the catalyst surface are dominant over the physical effects of the catalysts in the plasma-catalytic synthesis of ammonia. The highest NH₃ synthesis rate of 471 μmol g^–1 h^–1 was achieved using Ni/Al₂O₃ as a catalyst with plasma, which is 100% higher than that obtained using plasma only. The presence of a transition metal (e.g., Ni) on the surface of Al₂O₃ provided a more uniform plasma discharge than Al₂O₃ or plasma only, and enhanced the mean electron energy. The mechanism of plasma-catalytic ammonia synthesis has been investigated through operando plasma diagnostics combined with comprehensive characterization of the catalysts using N₂ physisorption measurements, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), NH₃-temperature-programmed desorption (TPD), and N₂-TPD. Four forms of adsorbed NH_x (x = 0, 1, 2, and 3) species were detected on the surfaces of the spent catalysts using XPS. It was found that metal sites and weak acid sites could enhance the production of NH₃ via formation of NH₂ intermediates on the surface.

COGNITIVE TRAJECTORIES BEFORE AND AFTER SLEEP TREATMENT INITIATION IN U.S. OLDER ADULTS WITH SLEEP DISTURBANCE

Sleep disturbances are associated with cognitive decline but it is not clear if initiation of sleep treatments mitigates decline. We used the 2006-2014 Health and Retirement Study. At each wave, participants were administered cognitive assessments and scores were summed (values=0-35; higher=better cognition). All participants also reported if, in the past two weeks, they had taken medications or used other treatments to improve sleep. Our sample (N=4,650) included individuals who at baseline were cognitively normal and untreated for sleep, and at any wave reported some sleep disturbance. We characterized cognitive performance over study period with comparisons before and after sleep treatment initiation. Between 2006-2014, participants exhibited declines in cognitive performance (B=-2.40; 95% CI=-2.73, -2.06; p<0.001) after controlling for confounders. Following sleep treatment, cognitive decline became less pronounced (interaction B=0.94; 95% CI=0.21, 1.67; p=0.013). Results suggest that in older adults with sleep disturbance, initiation of sleep treatment may slow cognitive decline.

Inhibition of miR-21 alleviated cardiac perivascular fibrosis via repressing EndMT in T1DM

In type 1 and type 2 diabetes mellitus, increased cardiac fibrosis, stiffness and associated diastolic dysfunction may be the earliest pathological phenomena in diabetic cardiomyopathy. Endothelial-mesenchymal transition (EndMT) in endothelia cells (ECs) is a critical cellular phenomenon that increases cardiac fibroblasts (CFs) and cardiac fibrosis in diabetic hearts. The purpose of this paper is to explore the molecular mechanism of miR-21 regulating EndMT and cardiac perivascular fibrosis in diabetic cardiomyopathy. In vivo, hyperglycaemia up-regulated the mRNA level of miR-21, aggravated cardiac dysfunction and collagen deposition. The condition was recovered by inhibition of miR-21 following with improving cardiac function and decreasing collagen deposition. miR-21 inhibition decreased cardiac perivascular fibrosis by suppressing EndMT and up-regulating SMAD7 whereas activating p-SMAD2 and p-SMAD3. In vitro, high glucose (HG) up-regulated miR-21 and induced EndMT in ECs, which was decreased by inhibition of miR-21. A highly conserved binding site of NF-κB located in miR-21 5'-UTR was identified. In ECs, SMAD7 is directly regulated by miR-21. In conclusion, the pathway of NF-κB/miR-21/SMAD7 regulated the process of EndMT in T1DM, in diabetic cardiomyopathy, which may be regarded as a potential clinical therapeutic target for cardiac perivascular fibrosis.

Associations Between Heart Rate Variability Measured With a Wrist-Worn Sensor and Older Adults' Physical Function: Observational Study

Background

Heart rate variability (HRV), or variation in beat-to-beat intervals of the heart, is a quantitative measure of autonomic regulation of the cardiovascular system. Low HRV derived from electrocardiogram (ECG) recordings is reported to be related to physical frailty in older adults. Recent advances in wearable technology offer opportunities to more easily integrate monitoring of HRV into regular clinical geriatric health assessments. However, signals obtained from ECG versus wearable photoplethysmography (PPG) devices are different, and a critical first step preceding their widespread use is to determine whether HRV metrics derived from PPG devices also relate to older adults’ physical function.

Objective

This study aimed to investigate associations between HRV measured with a wrist-worn PPG device, the Empatica E4 sensor, and validated clinical measures of both objective and self-reported physical function in a cohort of older adults living independently within a continuing care senior housing community. Our primary hypothesis was that lower HRV would be associated with lower physical function. In addition, we expected that HRV would explain a significant proportion of variance in measures of physical health status.

Methods

We evaluated 77 participants from an ongoing study of older adults aged between 65 and 95 years. The assessments encompassed a thorough examination of domains typically included in a geriatric health evaluation. We collected HRV data with the Empatica E4 device and examined bivariate correlations between HRV quantified with the triangular index (HRV TI) and 3 widely used and validated measures of physical functioning—the Short Physical Performance Battery (SPPB), Timed Up and Go (TUG), and Medical Outcomes Study Short Form 36 (SF-36) physical composite scores. We further investigated the additional predictive power of HRV TI on physical health status, as characterized by SF-36 physical composite scores and Cumulative Illness Rating Scale for Geriatrics (CIRS-G) scores, using generalized estimating equation regression analyses with backward elimination.

Results

We observed significant associations of HRV TI with SPPB (n=52; Spearman ρ=0.41; P=.003), TUG (n=51; ρ=−0.40; P=.004), SF-36 physical composite scores (n=49; ρ=0.37; P=.009), and CIRS-G scores (n=52, ρ=−0.43; P=.001). In addition, the HRV TI explained a significant proportion of variance in SF-36 physical composite scores (R²=0.28 vs 0.11 without HRV) and CIRS-G scores (R²=0.33 vs 0.17 without HRV).

Conclusions

The HRV TI measured with a relatively novel wrist-worn PPG device was related to both objective (SPPB and TUG) and self-reported (SF-36 physical composite) measures of physical function. In addition, the HRV TI explained additional variance in self-reported physical function and cumulative illness severity beyond traditionally measured aspects of physical health. Future steps include longitudinal tracking of changes in both HRV and physical function, which will add important insights regarding the predictive value of HRV as a biomarker of physical health in older adults.