Association between acetaminophen use and vitiligo in US women and men

BACKGROUND/OBJECTIVES

Exposure to chemical phenols, which can act as tyrosine analogues and result in anti-melanocyte autoimmunity, has been associated with vitiligo. Acetaminophen (N-acetyl-p-aminophenol) is an over-the-counter analgesic of phenolic origin. The risk of vitiligo with systemic exposure to acetaminophen has not yet been evaluated.

METHODS

We examined the risk of vitiligo with regular use acetaminophen in women, the Nurses' Health Study (NHS) and in men, the Health Professionals Follow-up Study (HPFS). Regular acetaminophen use was asked biennially from 1990 in NHS and from 1986 in HPFS, and the year of clinician-diagnosed vitiligo was asked retrospectively in 2012 in the cohorts.

RESULTS

In NHS, a total of 161 vitiligo cases were identified during a follow-up of 571,724 person-years; in HPFS, a total of 183 vitiligo cases were identified during a follow-up of 680,313 person-years. Regular use of acetaminophen was associated with an increased vitiligo risk in NHS but not HPFS. The multivariable relative risk (RR) was 1.52 (95% confidence interval [CI] 1.03-2.25) in NHS and 1.09 (95% CI 0.76-1.55) in HPFS. The higher risk of vitiligo was similar by duration of acetaminophen use in women; the multivariable RRs were 1.47 (95% CI 0.98-2.21) for acetaminophen use under 5 years, and 1.78 (95% CI 1.11-2.84) for acetaminophen use over 5 years.

CONCLUSIONS

Acetaminophen may be associated with a higher risk of vitiligo in women.

Transition to a first suicide attempt among young and middle-aged males with a history of suicidal thoughts: A two-year cohort study

INTRODUCTION

Although many studies have examined the risk and protective factors associated with suicidal behavior, little is known about the probability of transition from suicidal thoughts to suicidal attempts and the factors that distinguish those who have suicidal thoughts from those who progress to a suicide attempt.

OBJECTIVES

To determine the probability and predictors of transition to a suicide attempt among young and middle-aged males with a history of suicidal thoughts but no prior history of attempting suicide.

METHODS

We used data from the first two waves of the Australian Longitudinal Study on Male Health, approximately two years apart. We followed the cohort of males aged 18-55 years who, at wave 1, reported a lifetime history of suicidal ideation but no history of a prior suicide attempt. We report transition probabilities to a first suicide attempt at Wave 2 and used logistic regression models to examine baseline predictors of transition to a first suicide attempt over the two-year period among males aged 18 years and older.

RESULTS

From the 1,564 males with suicidal thoughts at wave 1,140 participants (8.9%; 95% CI:7.6,10.5) reported to have had their first suicide attempt in the two-year period. In multivariate analyses, males aged 30-39 (OR=0.31; 95% CI: 0.16,0.60), 40-49 (OR=0.47; 95% CI:0.24,0.91) and 50-55 (OR=0.31; 95% CI: 0.13,0.73) all had lower odds of a first suicide attempt compared to males aged 18-29 years. The odds of a first suicide attempt were significantly higher for males who were: living in inner regional areas (ref: major cities) (OR=2.32; 95% CI: 1.33,4.04); homosexual or bisexual (OR=2.51; 95% CI: 1.17,5.36); working night shift as their main job (OR=1.75; 95% CI: 1.05,2.91); and, living with a disability (OR=1.99; 95% CI: 1.07,3.65). Clinical indicators such as symptoms of depression and illicit substance use were not significant predictors of transition to a first suicide attempt in multivariate models, nor were indicators of social connection.

CONCLUSION

We estimated that 8.9% of Australian males aged 15-55 years with a history of suicidal thoughts and no prior history of suicide attempts will progress to a first suicide attempt within two-years. Neither psychological distress, illicit substance use nor social connection indicators were correlated with transition to a first suicide attempt. Rather, it was socio-demographic indicators that were associated with transition to a first suicide attempt.

A Mesoporous Tungsten Oxynitride Nanofibers/Graphite Felt Composite Electrode with High Catalytic Activity for the Cathode in Zn-Br Flow Battery

High electrochemical polarization during a redox reaction in the electrode of aqueous zinc-bromine flow batteries largely limits its practical implementation as an effective energy storage system. This study demonstrates a rationally-designed composite electrode that exhibits a lower electrochemical polarization by providing a higher number of catalytically-active sites for faster bromine reaction, compared to a conventional graphite felt cathode. The composite electrode is composed of electrically-conductive graphite felt (GF) and highly active mesoporous tungsten oxynitride nanofibers (mWONNFs) that are prepared by electrospinning and simple heat treatments. Addition of the 1D mWONNFs to porous GF produces a web-like structure that significantly facilitates the reaction kinetics and ion diffusion. The cell performance achieves in this study demonstrated high energy efficiencies of 89% and 80% at current densities of 20 and 80 mA cm^-2 , respectively. Furthermore, the cell can also be operated at a very high current density of 160 mA cm^-2 , demonstrating an energy efficiency of 62%. These results demonstrate the effectiveness of the mWONNF/GF composite as the electrode material in zinc-bromine flow batteries.

Correction: Carbon nanotube-titanium dioxide nanocomposite support for improved activity and stability of an iridium catalyst toward the oxygen evolution reaction

[This corrects the article DOI: 10.1039/D2RA05027G.].

Carbon nanotube-titanium dioxide nanocomposite support for improved activity and stability of an iridium catalyst toward the oxygen evolution reaction

In order to improve the electrocatalytic activity and stability of an iridium (Ir) nanoparticle catalyst toward the oxygen evolution reaction (OER) in acidic electrolyte, carbon nanotube and titanium dioxide nanocomposites (CNT@TiO₂) are presented as a high-performance support. TiO₂ was synthesized on CNTs by using a novel layer-by-layer solution coating method that mimics atomic layer deposition (ALD) but is cost-effective and scalable. In the nanocomposites, CNTs serve as the electron pathways and the surface TiO₂ layers protect CNTs from corrosion under the harsh OER conditions. Thus, CNT@TiO₂ demonstrates excellent corrosion resistance as well as a high electrical conductivity (1.6 ± 0.2 S cm^-1) comparable to that of Vulcan carbon (1.4 S cm^-1). The interaction between Ir and TiO₂ promotes the formation of Ir(iii) species, thereby enhancing the OER activity and stability of the Ir nanoparticle catalyst. Compared to commercial carbon-supported Ir (Ir/C) and Ir black catalysts, CNT@TiO₂-supported Ir exhibits superior OER activity and stability.

Neurofilament light as a predictive biomarker of unresolved chemotherapy-induced peripheral neuropathy in subjects receiving paclitaxel and carboplatin

Management of chemotherapy-induced peripheral neuropathy (CIPN) remains a significant challenge in the treatment of cancer. Risk mitigation for CIPN involves preemptive reduction of cumulative dose or reduction of dose intensity upon emergence of symptoms, despite the risk of reduced tumor efficacy. A predictive biomarker for dose-limiting CIPN could improve treatment outcomes by allowing providers to make informed decisions that balance both safety and efficacy. To identify a predictive biomarker of CIPN, markers of neurodegeneration neurofilament-light (NfL), glial fibrillary acidic protein (GFAP), tau and ubiquitin c-terminal hydrolase L1 (UCHL1) were assessed in serum of up to 88 subjects drawn 21 days following the first of 6 treatments with chemotherapeutics paclitaxel and carboplatin. Serum NfL and GFAP were increased with chemotherapy. Further, NfL change predicted subsequent onset of grade 2–3 CIPN during the remainder of the trial (mean treatment duration = 200 days) and trended toward stronger prediction of CIPN that remained unresolved at the end of the study. These results confirm previous reports that serum NfL is increased in CIPN and provide the first evidence that NfL can be used to identify subjects susceptible to dose-limiting paclitaxel and carboplatin induced CIPN prior to onset of symptoms.

Implementation of Evidence-Based Practices within Treatment-As-Usual and Evidence-Based Practice Initiatives

Publicly funded initiatives are underway to improve implementation of evidence-based practices (EBP) in youth mental health services. However, we know little about the success of these initiatives or about EBP implementation independent of such initiatives. We examined EBP implementation in a treatment as usual (TAU) state and in six states with publicly funded EBP initiatives (EBPIs). In Study 1, we examined providers' use of practices derived from the evidence base (PDEB) and their predictors among 780 providers in a TAU state. In Study 2, we conducted a systematic review of implementation strategies, outcomes, and predictors of EBP use in six state funded EBPIs. Study 1 suggests TAU providers use PDEB alongside practices without consistent research support; provider racial/ethnic minority status, learning theory orientation, and manual use predict greater PDEB use. Study 2 indicates EBPIs employ multiple recommended implementation strategies with variable outcomes across studies and measurement approaches. Predictors of EBP use in EBPIs also varied, though training, setting, and youth age were consistent predictors across studies. While sample differences and inconsistent measurement across studies made direct comparisons somewhat tenuous, rates of PDEB use in the TAU sample appeared similar to those in publicly funded EBPIs. However, two states reported comparisons with TAU samples and found higher EBP implementation under EBPI. Different predictors impacted EBP use in TAU versus EBPIs. Our findings highlight the need for improved evaluation of EBPIs including clear reporting standards for outcomes and more consistent, standardized measurement of EBP use in order to better understand and improve EBPIs.

Core-shell structured Li-Fe electrode for high energy and stable thermal battery

The thermal battery, a key source for powering defensive power systems, employs Li alloy-based anodes. However, the alloying increases the reduction potential of Li which lowers the overall working voltage and energy output. To overcome these issues, Li alloy must be replaced with pure Li. Utilizing pure Li requires a structure that can hold liquefied Li because the working temperature for the thermal battery exceeds the melting point of Li. The liquefied Li can leak out of the anode, causing short-circuit. A Li-Fe electrode (LiFE) in which Fe powder holds liquefied Li has been developed. In LiFE, higher Li content can lead to higher energy output but increases the risk of Li leakage. Thus, Li content in the LiFE has been limited. Here, we demonstrate a novel core-shell electrode structure to achieve a higher energy output. The proposed core-shell LiFE incorporates a high Li content core and a low Li content shell; high energy comes from the core and the shell prevents the Li from leakage. The fabricated core-shell structured electrode demonstrates the high energy of 9074 W s, an increase by 1.66 times compared to the low Li content LiFE with the conventionally used Li content (5509 W s).

Clinical Feasibility of Ultrafast Contrast-Enhanced T1-Weighted 3D-EPI for Evaluating Intracranial Enhancing Lesions in Oncology Patients: Comparison with Standard 3D MPRAGE Sequence

BACKGROUND AND PURPOSE

Contrast-enhanced 3D T1WI is a preferred sequence for brain tumor imaging despite the long scan time. This study investigated the clinical feasibility of ultrafast contrast-enhanced T1WI by 3D echo-planar imaging compared with a standard contrast-enhanced 3D MPRAGE sequence for evaluating intracranial enhancing lesions in oncology patients.

MATERIALS AND METHODS

Sixty-one patients in oncology underwent brain MR imaging including both contrast-enhanced T1WI, 3D-EPI and 3D MPRAGE, in a single examination session for evaluating intracranial tumors. Two neuroradiologists evaluated image quality, lesion conspicuity, diagnostic confidence, number and size of the lesions, and contrast-to-noise ratio measurements from the 2 different sequences.

RESULTS

Ultrafast 3D-EPI T1WI did not reveal significant differences in diagnostic confidence, contrast-to-noise ratio_{lesion/parenchyma}, and the number of enhancing lesions compared with MPRAGE (P > .05). However, ultrafast 3D-EPI T1WI revealed inferior image quality, inferior anatomic delineation and greater susceptibility artifacts with fewer motion artifacts than images obtained with MPRAGE. The mean contrast-to-noise ratio_WM/GM and visual conspicuity of the lesion on ultrafast 3D-EPI T1WI were lower than those of MPRAGE (P < .001).

CONCLUSIONS

Ultrafast 3D-EPI T1WI showed comparable diagnostic performance with sufficient image quality and a 7-fold reduction in scan time for evaluating intracranial enhancing lesions compared with standard MPRAGE, even though it was limited by an inferior image quality and frequent susceptibility artifacts. Therefore, we believe that ultrafast 3D-EPI T1WI may be a viable option in oncology patients prone to movement during imaging studies.

Reducing Time to Discovery: Materials and Molecular Modeling, Imaging, Informatics, and Integration

Multiscale and multimodal imaging of material structures and properties provides solid ground on which materials theory and design can flourish. Recently, KAIST announced 10 flagship research fields, which include KAIST Materials Revolution: Materials and Molecular Modeling, Imaging, Informatics and Integration (M3I3). The M3I3 initiative aims to reduce the time for the discovery, design and development of materials based on elucidating multiscale processing-structure-property relationship and materials hierarchy, which are to be quantified and understood through a combination of machine learning and scientific insights. In this review, we begin by introducing recent progress on related initiatives around the globe, such as the Materials Genome Initiative (U.S.), Materials Informatics (U.S.), the Materials Project (U.S.), the Open Quantum Materials Database (U.S.), Materials Research by Information Integration Initiative (Japan), Novel Materials Discovery (E.U.), the NOMAD repository (E.U.), Materials Scientific Data Sharing Network (China), Vom Materials Zur Innovation (Germany), and Creative Materials Discovery (Korea), and discuss the role of multiscale materials and molecular imaging combined with machine learning in realizing the vision of M3I3. Specifically, microscopies using photons, electrons, and physical probes will be revisited with a focus on the multiscale structural hierarchy, as well as structure-property relationships. Additionally, data mining from the literature combined with machine learning will be shown to be more efficient in finding the future direction of materials structures with improved properties than the classical approach. Examples of materials for applications in energy and information will be reviewed and discussed. A case study on the development of a Ni-Co-Mn cathode materials illustrates M3I3's approach to creating libraries of multiscale structure-property-processing relationships. We end with a future outlook toward recent developments in the field of M3I3.

Promoting the Reversible Oxygen Redox Reaction of Li-Excess Layered Cathode Materials with Surface Vanadium Cation Doping

Li-excess layered cathode (LLC) materials have a high theoretical specific capacity of 250 mAh g-1 induced by transition metal (cationic) and oxygen (anionic) redox activity. Especially, the oxygen redox reaction related to the activation of the Li2MnO3 domain plays the crucial role of providing a high specific capacity. However, it also induces an irreversible oxygen release and accelerates the layered-to-spinel phase transformation and capacity fading. Here, it is shown that surface doping of vanadium (V5+) cations into LLC material suppresses both the irreversible oxygen release and undesirable phase transformation, resulting in the improvement of capacity retention. The V-doped LLC shows a high discharge capacity of 244.3 ± 0.8 mAh g-1 with 92% retention after 100 cycles, whereas LLC delivers 233.6 ± 1.1 mAh g-1 with 74% retention. Furthermore, the average discharge voltage of V-doped LLC drops by only 0.33 V after 100 cycles, while LLC exhibits 0.43 V of average discharge voltage drop. Experimental and theoretical investigations indicate that doped V-doping increase the transition metal-oxygen (TM-O) covalency and affect the oxidation state of peroxo-like (O2) n - species during the delithiation process. The role of V-doping to make the oxygen redox reversible in LLC materials for high-energy density Li-ion batteries is illustrated here.

Origin of the Superior Electrochemical Performance of Amorphous-Phase Conversion-Reaction-Based Electrode Materials for Na-Ion Batteries: Formation of a Bicontinuous Metal Network

The realization of conversion type electrode materials in Na-ion batteries (NIBs) has been hindered due to the nucleation property of the active material. During the sodiation, the transition metal (TM) cations reduce to the metallic state, and the respective anions react with the sodium ions. As a result, the metal particles are surrounded by the matrix of the insulating sodium compound, resulting in loss of electrical contact among the TM particles. Here, an amorphous molybdenum sulfide (a-MoS_x) electrode is made highly reversible by suppressing TM particle growth via elongating the cation diffusion pathway. Because of the long distance among Mo atoms in a-MoS_x, the growth of Mo nuclei is limited. This leads to more frequent nucleation and formation of smaller particles (3-5 nm in diameter). Since the smaller particles have a larger surface area than the bigger particles, the electrical contacts among Mo particles are clearly retained. The a-MoS_x anode for NIBs demonstrates a high capacity and excellent cycling retention. This work establishes that the amorphous structure enhances the reversibility and cycling stability of conversion-reaction-based electrodes by elongating the diffusion pathway of the metal ions.

Genetic variants in the folate metabolic pathway genes predict cutaneous melanoma-specific survival

BACKGROUND

Folate metabolism plays an important role in DNA methylation and nucleic acid synthesis and thus may function as a regulatory factor in cancer development. Genome-wide association studies (GWASs) have identified some single-nucleotide polymorphisms (SNPs) associated with cutaneous melanoma-specific survival (CMSS), but no SNPs were found in genes involved in the folate metabolic pathway.

OBJECTIVES

To examine associations between SNPs in folate metabolic pathway genes and CMSS.

METHODS

We comprehensively evaluated 2645 (422 genotyped and 2223 imputed) common SNPs in folate metabolic pathway genes from a published GWAS of 858 patients from The University of Texas MD Anderson Cancer Center and performed the validation in another GWAS of 409 patients from the Nurses' Health Study and Health Professionals Follow-up Study, in which 95/858 (11·1%) and 48/409 (11·7%) patients died of cutaneous melanoma, respectively.

RESULTS

We identified two independent SNPs (MTHFD1 rs1950902 G>A and ALPL rs10917006 C>T) to be associated with CMSS in both datasets, and their meta-analysis yielded an allelic hazards ratio of 1·75 (95% confidence interval 1·32-2·32, P = 9·96 × 10^-5 ) and 2·05 (1·39-3·01, P = 2·84 × 10^-4 ), respectively. The genotype-phenotype correlation analyses provided additional support for the biological plausibility of these two variants' roles in tumour progression, suggesting that variation in SNP-related mRNA expression levels is likely to be the mechanism underlying the observed associations with CMSS.

CONCLUSIONS

Two possibly functional genetic variants, MTHFD1 rs1950902 and ALPL rs10917006, were likely to be independently or jointly associated with CMSS, which may add to personalized treatment in the future, once further validated. What is already known about this topic? Existing data show that survival rates vary among patients with melanoma with similar clinical characteristics; therefore, it is necessary to identify additional complementary biomarkers for melanoma-specific prognosis. A hypothesis-driven approach, by pooling the effects of single-nucleotide polymorphisms (SNPs) in a specific biological pathway as genetic risk scores, may provide a prognostic utility, and genetic variants of genes in folate metabolism have been reported to be associated with cancer risk. What does this study add? Two genetic variants in the folate metabolic pathway genes, MTHFD1 rs1950902 and ALPL rs10917006, are significantly associated with cutaneous melanoma-specific survival (CMSS). What is the translational message? The identification of genetic variants will make a risk-prediction model possible for CMSS. The SNPs in the folate metabolic pathway genes, once validated in larger studies, may be useful in the personalized management and treatment of patients with cutaneous melanoma.

Fingerprint Voltammograms of Copper Single Crystals under Alkaline Conditions: A Fundamental Mechanistic Analysis

A critical step toward the systematic development of electrocatalysts is the determination of the microscopic structure and processes at the electrified solid/electrolyte interface. The major challenges toward this end for experiment and computations are achieving sufficient cleanliness and modeling the complexity of electrochemical systems, respectively. In this sense, benchmarks of well-defined model systems are sparse. This work presents a rigorous joint experimental-theoretical study on the single-crystal (SC) Cu/aqueous interface. Within typical computational uncertainties, we find quantitative agreement between simulated and experimentally measured voltammograms, which allows us to unequivocally identify the *OH adsorption feature in the fingerprint region of Cu(110), Cu(100), and Cu(111) SCs under alkaline conditions. We find the inclusion of hydrogen evolution reaction kinetics in the theoretical model to be crucial for an accurate steady-state description that gives rise to a negligible H* coverage. A purely thermodynamic description of the H* coverage through a Pourbaix analysis would incorrectly lead to a H* adsorption peak. The presented results establish a fundamental benchmark for all electrochemical applications of Cu.

Association of blood mercury levels with nonmelanoma skin cancer in the U.S.A. using National Health and Nutrition Examination Survey data (2003-2016)

BACKGROUND

Some studies have reported increased incidence or mortality of lung and brain cancers associated with occupations involving potential mercury exposure. Epidemiological evidence related to skin cancer is also limited.

OBJECTIVES

To investigate the association between blood mercury (Hg) levels and nonmelanoma skin cancer (NMSC).

METHODS

We used National Health and Nutrition Examination Survey data from 2003 to 2016. The exposures were blood total (tHg), inorganic (iHg) and methylmercury (MeHg). The outcome was a self-reported diagnosis of NMSC. We included participants aged ≥ 20 years who had information on blood mercury and sociodemographic factors. We conducted a logistic regression analysis to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the risk of NMSC associated with quartiles of blood Hg, after adjusting for the sociodemographic factors and survey year.

RESULTS

The number of participants was 29 413; mean age was 49 years and 52% were female. Compared with those with a tHg ≤ 0·47 μg L^-1 (Q1), those with a tHg > 1·74 μg L^-1 (Q4) had nearly double the odds of NMSC (OR 1·79, 95% CI 1·19-2·71; P_trend = 0·004). Similarly, those in the highest quartile of MeHg (> 1·44 μg L^-1 ) had 1·7 times greater odds of NMSC (OR 1·74, 95% CI 1·13-2·70; P_trend = 0·01) than those in the lowest quartile (≤ 0·21 μg L^-1 ). iHg levels were nonsignificantly positively associated with NMSC (P_trend = 0·08).

CONCLUSIONS

We found that higher blood tHg and MeHg levels were associated with a higher prevalence of NMSC. Linked Comment: Taylor. Br J Dermatol 2020; 183:413-414.

Do severe maternal morbidity and adequate prenatal care affect the delivery cost? A nationwide cohort study for 11 years with follow up

OBJECTIVE

To explore whether severe maternal morbidity (SMM) and adequate prenatal care (PNC) affect delivery cost.

DESIGN

Population-based retrospective cohort study.

SETTING

National Health Insurance Service National Sample Cohort in Korea.

POPULATION

A total of 90 035 deliveries in 2003 and 2013.

METHODS

Severe maternal morbidity was determined using the Centers for Disease Control and Prevention's algorithm. Delivery medical costs were calculated by estimating claimed total medical costs using year-specific inflation adjustment factors. Adequate PNC was estimated by the Kessner Adequacy of Prenatal Care Index. To estimate adjusted mean delivery medical costs related to SMM, we applied a generalised estimating equation model with log link and γ distribution, by adjusting for all covariates.

MAIN OUTCOME MEASURES

Delivery cost was calculated by estimating claimed total medical cost during delivery hospitalisation using year-specific inflation.

RESULTS

Of the 90 035 deliveries, 2041 (2.27%) involved SMM. Women with SMM had a greater adjusted mean cost of delivery (US$ 1,263, 95% CI US$ 1,196-1,334) than those without (US$ 740, 95% CI US$ 729-750). Interestingly, women who had inadequate PNC had higher delivery medical costs than those with adequate PNC, adjusted for all covariates.

CONCLUSION

Delivery involving SMM was associated with nearly doubled medical costs. Additionally, inadequate PNC increased the medical costs of delivery. The current study confirmed the burden of SMM and found that adequate PNC might be a useful preventive factor in reducing medical costs.

TWEETABLE ABSTRACT

We found that women with severe maternal morbidity and inadequate prenatal care had increased medical costs during delivery hospitalisation.

Diagnosis validation and clinical characterization of atopic dermatitis in Nurses' Health Study 2

BACKGROUND

Epidemiologic studies of atopic dermatitis (AD) are often limited by case definitions that have not been validated.

OBJECTIVE

In this study, we assessed the accuracy of self-report of AD in a large cohort of US female nurses, the Nurses' Health Study 2 (NHS2). We also provide clinical characteristics of AD in the cohort.

METHODS

We sent an electronic questionnaire to NHS2 participants who previously reported ever having a diagnosis of AD. This questionnaire was designed to confirm cases of AD using previously validated algorithms with >85% specificity. We assessed the association of AD with asthma, comparing the results when different definitions of AD were applied. We also inquired about various aspects of participants' AD.

RESULTS

Responses were received from 2509 of 5126 (49%) nurses who were sent the questionnaire, with an average age of 62. Most participants (1996/2509, 80%) reiterated their previously reported clinician diagnosis of AD. Application of the two diagnostic algorithms yielded confirmation of 1538 and 1293 prevalent cases, respectively. The association of AD with asthma was stronger when more stringent AD case definitions were applied. Participants generally reported mild disease (92% with ≤10% maximal body surface area involved) and a high proportion (57%) reported adult-onset disease.

CONCLUSIONS

Self-report of AD diagnosis has good reliability, and future analyses will be strengthened by our ability to conduct sensitivity analyses with refined confirmed AD subgroups.

Gender differences, UV exposure and risk of lentigo maligna in a nationwide healthcare population cohort study

BACKGROUND

Our understanding of the relationship between ultraviolet (UV) radiation exposure and lentigo maligna (LM) has been largely derived from epidemiologic/clinical studies based on invasive melanoma. Recent studies have shown gender differences in melanocytic tumours incidence.

OBJECTIVE

To examine the association of UV light with LM by gender remains unclear.

METHODS

Two prospective cohort study [Nurses' Health Study (1980-2012)] and [Health Professionals Follow-up Study (1986-2010)] were analysed. All participants with LM or MIS, non-LM type were included in analysis. UV index at birth, age 15, and age 30 were calculated by gender. Lifetime UV flux was calculated. Hazard ratios (HRs) were calculated.

RESULTS

A total of 110 485 women from NHS and 41 015 men from HPFS were examined. A total of 281 LM and 776 melanoma in situ (MIS), non-LM cases were reported. Risk of LM increased with increasing UV flux exposure in multivariate-adjusted models for men (P for trend = 0.04), but not for women (P for trend = 0.91).

CONCLUSIONS

UV flux may be associated with LM in men but not in women.

Ga-Doped Pt-Ni Octahedral Nanoparticles as a Highly Active and Durable Electrocatalyst for Oxygen Reduction Reaction

Bimetallic PtNi nanoparticles have been considered as a promising electrocatalyst for oxygen reduction reaction (ORR) in polymer electrolyte membrane fuel cells (PEMFCs) owing to their high catalytic activity. However, under typical fuel cell operating conditions, Ni atoms easily dissolve into the electrolyte, resulting in degradation of the catalyst and the membrane-electrode assembly (MEA). Here, we report gallium-doped PtNi octahedral nanoparticles on a carbon support (Ga-PtNi/C). The Ga-PtNi/C shows high ORR activity, marking an 11.7-fold improvement in the mass activity (1.24 A mg_Pt^-1) and a 17.3-fold improvement in the specific activity (2.53 mA cm^-2) compared to the commercial Pt/C (0.106 A mg_Pt^-1 and 0.146 mA cm^-2). Density functional theory calculations demonstrate that addition of Ga to octahedral PtNi can cause an increase in the oxygen intermediate binding energy, leading to the enhanced catalytic activity toward ORR. In a voltage-cycling test, the Ga-PtNi/C exhibits superior stability to PtNi/C and the commercial Pt/C, maintaining the initial Ni concentration and octahedral shape of the nanoparticles. Single cell using the Ga-PtNi/C exhibits higher initial performance and durability than those using the PtNi/C and the commercial Pt/C. The majority of the Ga-PtNi nanoparticles well maintain the octahedral shape without agglomeration after the single cell durability test (30,000 cycles). This work demonstrates that the octahedral Ga-PtNi/C can be utilized as a highly active and durable ORR catalyst in practical fuel cell applications.

Synthesis of Chemically Ordered Pt3Fe/C Intermetallic Electrocatalysts for Oxygen Reduction Reaction with Enhanced Activity and Durability via a Removable Carbon Coating

Recently, Pt₃M (M = Fe, Ni, Co, Cu, etc.) intermetallic compounds have been highlighted as promising candidates for oxygen reduction reaction (ORR) catalysts. In general, to form those intermetallic compounds, alloy phase nanoparticles are synthesized and then heat-treated at a high temperature. However, nanoparticles easily agglomerate during the heat treatment, resulting in a decrease in electrochemical surface area (ECSA). In this study, we synthesized Pt-Fe alloy nanoparticles and employed carbon coating to protect the nanoparticles from agglomeration during heat treatment. As a result, Pt₃Fe L1₂ structure was obtained without agglomeration of the nanoparticles; the ECSA of Pt-Fe alloy and intermetallic Pt₃Fe/C was 37.6 and 33.3 m² g_Pt^-1, respectively. Pt₃Fe/C exhibited excellent mass activity (0.454 A mg_Pt^-1) and stability with superior resistances to nanoparticle agglomeration and iron leaching. Density functional theory (DFT) calculation revealed that, owing to the higher dissolution potential of Fe atoms on the Pt₃Fe surface than those on the Pt-Fe alloy, Pt₃Fe/C had better stability than Pt-Fe/C. A single cell fabricated with Pt₃Fe/C showed higher initial performance and superior durability, compared to that with commercial Pt/C. We suggest that Pt₃M chemically ordered electrocatalysts are excellent candidates that may become the most active and durable ORR catalysts available.