Omega-3 fatty acids supplementation on major cardiovascular outcomes: an umbrella review of meta-analyses of observational studies and randomized controlled trials

OBJECTIVE: Omega-3 fatty acids are commonly used as a lipid-lowering agent or dietary supplement for the purpose of prevention of cardiovascular diseases. However, even large-scale clinical trials have not shown significant results demonstrating clear clinical benefits in cardiovascular diseases. Thus, this umbrella review aims to summarize and evaluate the evidence of clinical effects of omega-3 fatty acids supplementation on cardiovascular outcomes through comprehensive analyses of previous randomized controlled trials (RCTs) or observational cohort studies. MATERIALS AND METHODS: We conducted relevant publication search in PubMed, Embase, and Cochrane Database of Systematic Reviews. We retrieved and analyzed 3,298 articles published until August 28th, 2019. RESULTS: We identified 29 relevant articles and analyzed 83 meta-analyses of RCTs or cohort studies therefrom. As a result, we identified 12 cardiovascular outcomes that are related to omega-3 fatty acids supplementation. Among them, total mortality from major cardiovascular causes (RR 0.92, 95% CI 0.86 to 0.98) had significant inverse associations, and moreover, statistical significances were maintained even in subgroup analysis of large-scale RCTs including more than 1,000 patients (RR 0.94, 95% CI 0.88 to 0.99). CONCLUSIONS: Our umbrella review study shows that omega-3 fatty acids supplementation have a clinical benefit in reducing mortality from cardiovascular causes. However, many studies still have shown conflicting results, and therefore, further studies will be needed to verify the clinical benefit of omega-3 supplementation

Paternal Mental Health and Parenting in the COVID-19 Pandemic Era

The COVID-19 pandemic has negatively affected the family economy by threatening job security, which has been acting as a source of stress for fathers. Social distancing has increased father-child interaction time and the burden of parenting. The parenting stress levels of fathers increased, and mental health problems such as depression and anxiety were induced. This was reported to be more serious in vulnerable groups, according to the race or socioeconomic status of the fathers. Fathers’ mental health problems in the context of COVID-19 affect father-child relationships and children’s adjustment in the long term. Healthcare professionals must develop community-based intervention programs to screen fathers’ risk factors and educate them on mental health issues, while considering the changing roles and mental health of fathers during the pandemic. Before another epidemic breaks out

Men's mental health during the COVID-19 pandemic: a scoping review

Background: Mental health issues can be more severe in men vulnerable to isolation and loneliness during a pandemic because of social distancing and isolation measures. The purpose of this study was to identify current research trends and the impact of the coronavirus disease (COVID-19) on men’s mental health through a scoping review, and to make recommendations for improvements. Methods: This study conducted a scoping review to explore and analyze research trends on the effect of COVID-19 on men’s mental health during the period January 2020 to October 2021. The PubMed and CINAHL databases, as well as Google Scholar, were used to identify relevant studies. The two researchers individually reviewed the studies, and all references were reviewed to determine the final sample of included studies. Results: A total of 27 studies were included in the analysis. Of all the studies, 14 were descriptive, one was quasi-experimental, and six were qualitative. Remaining studies included four commentaries, one case study, and one review. COVID-19 was found to impact the following areas of men’s mental health at the individual level: psychological distress, addictive behaviors, sleep, well-being, cognitive function, and coping. At the interpersonal level, family outcomes, community belonging, and violence were impacted. At the social level, masculinity, inequity, and social service changes were affected. Intervention strategies for men’s mental health during COVID-19 recommended by these studies were also divided into three levels (individual, interpersonal, and social level). Conclusions: Efforts should be made to improve mental health services for men who may experience anxiety, depression, and anger, along with the physical health concerns of the COVID-19 era

CdS Nanowire Solar Cells: Dual Role of Squaraine Dye as a Sensitizer and a Hole Transporter

The squaraine dye (SQ) anchored onto CdS nanowires serves as a photosensitizing dye and a hole acceptor. This dual role of the squaraine dye has been successfully exploited in a nanowire solar cell to improve the photoconversion efficiency. Electrophoretic deposition of CdS NWs and CdS NWs+SQ composite onto conducting glass electrodes was performed to obtain robust photoanodes and evaluate the photovoltaic performance of nanowire solar cells (NWSCs). Whereas the sensitization property of the SQ extends the response of CdS NWSCs into the near-IR (NIR) region, its redox property facilitates shuttling of holes to the electrolyte and suppressing the charge recombination process. Transient absorption measurements confirm the formation of cation radical of the dye arising from these two processes. The dual role of the squaraine dye has enabled us to improve the power conversion efficiency of NWSCs by a factor of ∼20. Photoelectrochemical, spectroelectrochemical, and spectroscopic measurements provide insight into the multifaceted role of squaraine dye in improving the performance of NWSCs

Size-Dependent Energy Transfer Pathways in CdSe Quantum Dot–Squaraine Light-Harvesting Assemblies: Förster versus Dexter

Energy transfer coupled with electron transfer is a convenient approach to mimic photosynthesis in light energy conversion. Better understanding of mechanistic details of energy transfer processes is important to enhance the performance of dye or quantum dot-sensitized solar cells. Energy transfer through both long-range dipole-based Förster resonance energy transfer (FRET) and short-range Dexter energy transfer (DET) mechanisms have been identified to occur between CdSe quantum dots (QDs) linked to a red-infrared-absorbing squaraine dye through a short thiol functional group (SQSH). Solutions of SQSH linked to CdSe were investigated through steady-state and time-resolved spectroscopy experiments to explore both mechanisms. Photoluminescence studies revealed that smaller QDs had higher energy transfer efficiencies than predicted by FRET, and femtosecond transient absorption experiments revealed faster energy transfer rates in smaller donor QD sizes. These findings supported a DET process dominating at small donor sizes. The presence of both processes illustrates multiple strategies for utilizing energy transfer in light-harvesting assemblies and the required considerations in device design to maximize energy transfer gains through either mechanism

Metal-Cluster-Sensitized Solar Cells. A New Class of Thiolated Gold Sensitizers Delivering Efficiency Greater Than 2%

A new class of metal-cluster sensitizers has been explored for designing high-efficiency solar cells. Thiol-protected gold clusters which exhibit molecular-like properties have been found to inject electrons into TiO₂ nanostructures under visible excitation. Mesoscopic TiO₂ films modified with gold clusters deliver stable photocurrent of 3.96 mA/cm² with power conversion efficiencies of 2.3% under AM 1.5 illumination. The overall absorption features and cell performance of metal-cluster-sensitized solar cells (MCSCs) are comparable to those of CdS quantum-dot-based solar cells (QDSCs). The relatively high open-circuit voltage of 832 mV and fill factor of 0.7 for MCSCs as compared to QDSCs show the viability of these new sensitizers as alternatives to semiconductor QDs and sensitizing dyes in the next generation of solar cells. The superior performance of MCSCs discussed in this maiden study lays the foundation to explore other metal clusters with broader visible absorption

Synchronized Energy and Electron Transfer Processes in Covalently Linked CdSe–Squaraine Dye–TiO₂ Light Harvesting Assembly

Manipulation of energy and electron transfer processes in a light harvesting assembly is an important criterion to mimic natural photosynthesis. We have now succeeded in sequentially assembling CdSe quantum dot (QD) and squaraine dye (SQSH) on TiO₂ film and couple energy and electron transfer processes to generate photocurrent in a hybrid solar cell. When attached separately, both CdSe QDs and SQSH inject electrons into TiO₂ under visible–near-IR irradiation. However, CdSe QD if linked to TiO₂ with SQSH linker participates in an energy transfer process. The hybrid solar cells prepared with squaraine dye as a linker between CdSe QD and TiO₂ exhibited power conversion efficiency of 3.65% and good stability during illumination with global AM 1.5 solar condition. Transient absorption spectroscopy measurements provided further insight into the energy transfer between excited CdSe QD and SQSH (rate constant of 6.7 × 10¹⁰ s^–1) and interfacial electron transfer between excited SQSH and TiO₂ (rate constant of 1.2 × 10¹¹ s^–1). The synergy of covalently linked semiconductor quantum dots and near-IR absorbing squaraine dye provides new opportunities to harvest photons from selective regions of the solar spectrum in an efficient manner

Sequentially Layered CdSe/CdS Nanowire Architecture for Improved Nanowire Solar Cell Performance

The power conversion efficiency of semiconductor nanowire (NW) based solar cells as compared to quantum dot solar cell (QDSC) has remained lower, and efforts to improve the photovoltaic performance of semiconductor NWs continue. We have now succeeded in using a layered architecture of CdS and CdSe NWs for improving the photovoltaic performance of nanowire solar cell (NWSC). The photoanode designed with sequentially deposited films of CdSe and CdS NWs delivered a power conversion efficiency of 1%. This efficiency of CdSe/CdS composite is an order of magnitude improvement over single nanowire system (CdS or CdSe) based solar cell. The improvement seen in the CdSe/CdS composite film is attributed to charge rectification and improvement of electron and hole separation and transport in the opposite direction. Impedance spectroscopy demonstrates the beneficial effect of type II structure in CdSe/CdS sequential deposition through lower transport resistance, which remains a dominating effect in dictating the overall performance of the NWSC

<i>Know Thy Nano Neighbor</i>. Plasmonic <i>versus</i> Electron Charging Effects of Metal Nanoparticles in Dye-Sensitized Solar Cells

Neighboring metal nanoparticles influence photovoltaic and photocatalytic behavior of semiconductor nanostructures either through Fermi level equilibration by accepting electrons or inducing localized surface plasmon effects. By employing SiO₂- and TiO₂-capped Au nanoparticles we have identified the mechanism with which the performance of dye-sensitized solar cells (DSSC) is influenced by the neighboring metal nanoparticles. The efficiency of an N719 dye-sensitized solar cell (9.3%) increased to 10.2% upon incorporation of 0.7% Au@SiO₂ and to 9.8% upon loading of 0.7% Au@TiO₂ nanoparticles. The plasmonic effect as monitored by introducing Au@SiO₂ in DSSC produces higher photocurrent. However, Au nanoparticles undergo charge equilibration with TiO₂ nanoparticles and shift the apparent Fermi level of the composite to more negative potentials. As a result, Au@TiO₂ nanoparticle-embedded DSSC exhibit higher photovoltage. A better understanding of these two effects is crucial in exploiting the beneficial aspects of metal nanoparticles in photovoltaics