Formic acid catalyzed isomerization and adduct formation of an isoprene-derived Criegee intermediate: experiment and theory

Isoprene is the most abundant non-methane hydrocarbon emitted into the Earth's atmosphere. Ozonolysis is an important atmospheric sink for isoprene, which generates reactive carbonyl oxide species (R₁R₂C O⁺O⁻) known as Criegee intermediates. This study focuses on characterizing the catalyzed isomerization and adduct formation pathways for the reaction between formic acid and methyl vinyl ketone oxide (MVK-oxide), a four-carbon unsaturated Criegee intermediate generated from isoprene ozonolysis. syn-MVK-oxide undergoes intramolecular 1,4 H-atom transfer to form a substituted vinyl hydroperoxide intermediate, 2-hydroperoxybuta-1,3-diene (HPBD), which subsequently decomposes to hydroxyl and vinoxylic radical products. Here, we report direct observation of HPBD generated by formic acid catalyzed isomerization of MVK-oxide under thermal conditions (298 K, 10 torr) using multiplexed photoionization mass spectrometry. The acid catalyzed isomerization of MVK-oxide proceeds by a double hydrogen-bonded interaction followed by a concerted H-atom transfer via submerged barriers to produce HPBD and regenerate formic acid. The analogous isomerization pathway catalyzed with deuterated formic acid (D2-formic acid) enables migration of a D atom to yield partially deuterated HPBD (DPBD), which is identified by its distinct mass (m/z 87) and photoionization threshold. In addition, bimolecular reaction of MVK-oxide with D2-formic acid forms a functionalized hydroperoxide adduct, which is the dominant product channel, and is compared to a previous bimolecular reaction study with normal formic acid. Complementary high-level theoretical calculations are performed to further investigate the reaction pathways and kinetics

GeneMatch: A novel recruitment registry using at‐home APOE genotyping to enhance referrals to Alzheimer’s prevention studies

IntroductionRecruitment for Alzheimer’s disease (AD) prevention research studies is challenging because of lack of awareness among cognitively healthy adults coupled with the high screen fail rate due to participants not having a genetic risk factor or biomarker evidence of the disease. Participant recruitment registries offer one solution for efficiently and effectively identifying, characterizing, and connecting potential eligible volunteers to studies.MethodsIndividuals aged 55‐75 years who live in the United States and self‐report not having a diagnosis of cognitive impairment such as MCI or dementia are eligible to join GeneMatch. Participants enroll online and are provided a cheek swab kit for DNA extraction and apolipoprotein E (APOE) genotyping. Participants are not told their APOE results, although the results may be used in part to help match participants to AD prevention studies.ResultsAs of August 2018, 75,351 participants had joined GeneMatch. Nearly 30% of participants have one APOE4 allele, and approximately 3% have two APOE4 alleles. The percentages of APOE4 heterozygotes and homozygotes are inversely associated with age (P < .001).DiscussionGeneMatch, the first trial‐independent research enrollment program designed to recruit and refer cognitively healthy adults to AD prevention studies based in part on APOE test results, provides a novel mechanism to accelerate prescreening and enrollment for AD prevention trials.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/152681/1/alzjjalz201812007.pd

The Lantern Vol. 50, No. 2, Spring 1984

• The Storm • Je ne sais pas • The Ghetious Blastious • An Empty Cradle • The Playing Hands • Battle Hymn • A Limerick • Parting Thoughts • The River • Miss You • De la Tristeza • Two So Special • Time of the Unicorn • The Absence • Thru The Breeze • Is the World Really a Round Ball? • Brother • To Michael • Gravity • Refuge • Der Witwer • Plastic Flowers Never Die • Book on the Shelfhttps://digitalcommons.ursinus.edu/lantern/1124/thumbnail.jp

Time-dependent suicide rates among Army soldiers returning from an Afghanistan/Iraq deployment, by military rank and component

Abstract Background To date, knowledge is limited regarding time-dependent suicide risk in the years following return from deployment and whether such rates vary by military rank (i.e., enlisted, officer) or component (i.e., active duty, National Guard, reserve). To address these gaps in knowledge, the objectives of this study were to determine and compare postdeployment suicide rates and trends (percent change over time), and hazard rates for Army soldiers, by rank and component (measured at the end of the deployment). Methods Longitudinal cohort study of 860,930 Army soldiers returning from Afghanistan/Iraq deployment in fiscal years 2008–2014 from the Substance Use and Psychological Injury Combat study. Death by suicide was observed from the end of the first deployment in the study period through 2018 (i.e., the most recently available mortality data) for up to 11 years of follow-up. Analyses were conducted in 2021–2022. Results Adjusting for age, lowest-ranking Junior Enlisted (E1–E4) soldiers had a suicide rate 1.58 times higher than Senior Enlisted (E5–E9)/Warrant Officers (95% CI [1.24, 2.01]) and 2.41 times higher than Officers (95% CI [1.78, 3.29]). Suicide rates among lower-ranking enlisted soldiers remained elevated for 11 years postdeployment. Overall and annual postdeployment suicide rates did not differ significantly across components. Comparisons across rank and component for females were generally consistent with the full cohort results. Conclusions Lower-ranking enlisted soldiers had the highest rate of suicide, underscoring the importance of understanding rank as it relates to social determinants of health. For over a decade following Afghanistan/Iraq deployment, lower-enlisted rank during deployment was associated with an elevated rate of suicide; thereby suggesting that postdeployment prevention interventions targeting lower-ranking military members are warranted

Trends in suicide rates by race and ethnicity among members of the United States Army.

Efforts were focused on identifying differences in suicide rates and time-dependent hazard rate trends, overall and within age groups, by race and ethnicity among United States Army members who returned from an index deployment (October 2007 to September 2014). This retrospective cohort study was conducted using an existing longitudinal database, the Substance Use and Psychological Injury Combat Study (SUPIC). Demographic (e.g., race and ethnicity) and military data from the Department of Defense compiled within SUPIC, as well as Department of Veterans Affairs data were linked with National Death Index records (through 2018) to identify deaths by suicide including those that occurred after military service. The cohort included 860,930 Army Service members (Active Duty, National Guard, and Reserve). Age-adjusted (using the direct standardization method) and age-specific suicide rates per 100,000 person years were calculated and rate ratios (RR) were used for comparisons. Trends were evaluated using hazard rates over time since the end of individuals' index deployments. Among those aged 18-29 at the end of their index deployment, the suicide rate for American Indian/Alaskan Native (AI/AN) individuals was 1.51 times higher (95% confidence interval [CI]: 1.03, 2.14) compared to White non-Hispanic individuals (WNH), and lower for Hispanic and Black non-Hispanic (BNH) than for WNH individuals (RR = 0.65 [95% CI: 0.55, 0.77] and RR = 0.71 [95% CI: 0.61, 0.82], respectively). However, analyses revealed increasing trends in hazard rates post-deployment (≤ 6.5 years) within groups of Hispanic and BNH individuals (Average Annual Percent Change [APC]: 12.1% [95% CI: 1.3%, 24.1%] and 11.4% [95% CI: 6.9%, 16.0%], respectively) with a smaller, increase for WNH individuals (APC: 3.1%; 95% CI: 0.1%, 6.1%). Findings highlight key subgroups at risk for post-deployment suicide (i.e., WNH, AI/AN and younger individuals), as well as heterogeneous trends overtime, with rates and trends varying within race and ethnic groups by age groups. Post-deployment suicide prevention efforts that address culturally relevant factors and social determinants of health associated with health inequities are needed

F4‐02‐01: Connect 4 APOE: A Randomized Study of Phone Versus Videoconference Delivery of APOE Genotype Disclosure in the Generation Study

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/153236/1/alzjjalz201606592.pd