Trends in e-cigarette flavour use and demographic correlates among US youth from 2020 to 2023.

Background: As US electronic cigarette (e-cigarette) flavour policies became increasingly restrictive during 2020-2023, flavoured e-cigarette use by the youth might have shifted.

Methods: US eighth, 10th and 12th graders in the Monitoring the Future study assessed the past 12-month nicotine vaping by flavour, in annual cross-sectional surveys over 2020-2023 (n=91 220). Among the past 12-month users (n=17 761), the e-cigarette flavour youth reported using most often was analysed by year, demographic/vaping pattern and year × demographic/vaping interaction using log-binomial regression.

Awareness and Use of Vaping Products With a Nicotine Analogue Among Adolescents and Young Adults.

Objective: E-cigarettes and other products containing synthetic nicotine analogues, such as 6-methyl-nicotine, are exempted from US premarket tobacco product application (PMTA) requirements, allowing rapid market expansion. Understanding the prevalence and correlates of adolescents' and young adults' (AYA) awareness and use of nicotine analogue products is critical for informing pediatric care, youth-focused interventions, and regulatory actions.

Methods: A cross-sectional survey was conducted during May to June 2024 among US participants aged 14 to 25 years (N = 1760) oversampled with ever-tobacco-product-using AYA recruited by a convenience online sampling panel.

E-Cigarette and Cannabis Social Media Posts and Adolescent Substance Use.

Importance: Adolescents are exposed to e-cigarette and cannabis content on social media. Understanding associations of these exposures with use and dual use of these products can guide regulations.

Objective: To assess whether adolescent exposure to e-cigarette and/or cannabis content on social media, including posts by various content creators, is associated with e-cigarette, cannabis, and dual use.

Oral Nicotine Product Use and Vaping Progression Among Adolescents.

Background And Objectives: Use of flavored oral nicotine products (ONPs), including nicotine pouches and other ONPs (eg, gums and lozenges) is increasing among adolescents who use e-cigarettes (ie, vape). It is unknown whether ONP use is associated with vaping behaviors.

Methods: We used data from 6 semiannual waves of a prospective cohort of Southern California adolescents (2021-2024).

Nicotine Pouch and E-Cigarette Use and Co-Use Among US Youths in 2023 and 2024.

Importance: The market sector of flavored commercial nicotine products without tobacco leaves recently expanded to nicotine pouches. Comprehensive epidemiologic analyses of patterns and trends in youth use of commercial nontobacco nicotine products are lacking.

Objective: To estimate US youth nicotine pouch and e-cigarette use prevalence and associated sociodemographic variables in 2023 and 2024.

Correction: Investigation of injury severity level in truck-related crashes at school zones using mixed generalized ordered models.

[This corrects the article DOI: 10.1371/journal.pone.

Longitudinal patterns of e-cigarette use initiation and progression to frequent vaping from mid-to-late adolescence to young adulthood.

Aims: This exploratory study aimed to describe longitudinal patterns of e-cigarette use initiation and progression to frequent use across mid-to-late adolescence and young adulthood and determine risk factors for and consequences of these initiation patterns.

Design: Using 12 waves of a prospective cohort data across 2014-2023, we identified latent classes with distinct patterns of timing of e-cigarette use initiation and frequent use progression (20 + days/month). We then estimated: (1) associations of baseline risk factors with membership in latent classes and (2) associations of latent classes with e-cigarette/other substance use frequency and e-cigarette dependence at a subsequent 1-year follow-up.

Impact of Instagram and TikTok influencer marketing on perceptions of e-cigarettes and perceptions of influencers in young adults: a randomised survey-based experiment.

Background: Pairing e-cigarettes with healthy lifestyle contexts in influencers' promotional social media posts may increase e-cigarette use risk among young adults. This study examined the effects of e-cigarette and healthy lifestyle content on young adults' perceptions of influencer credibility, harm perceptions of, and susceptibility to use, e-cigarettes.

Methods: In this survey-based online, repeated-measures experiment (2023), California young adults (N=1494, M=23 (SD=1.

Investigation of injury severity level in truck-related crashes at school zones using mixed generalized ordered models.

The number of truck registrations is steadily increasing in Korea. The proportion of truck deaths compared to the total number of traffic crashes was 23.9%, which is significantly higher than that of other vehicles.

Entropically driven phase separation and effective multibody interactions in block copolymers.

The need for effective multibody interactions is asserted in understanding the entropically driven phase separation of diblock copolymers, arising from disparity in self cohesion and association between dissimilar components. Through Landau analysis combined with a molecular equation of state to describe associability, it is demonstrated that diblock copolymers can exhibit dual critical points. We highlight the significance of multibody effects in correctly locating these critical points.

Prospective Associations of Exposure to Discrimination and Alcohol Use: A National Longitudinal Study.

Introduction: This study examined prospective associations of perceived discrimination experience and past-week alcohol use among U.S. adults.

Association of discrimination experiences with rapid subsequent changes in anxiety and depressive symptoms in US adults during the COVID-19 pandemic.

This study explores how discrimination experiences during the COVID-19 pandemic relate to anxiety and depressive symptoms in US adults. Using a national representative intensive longitudinal survey, the study evaluates rapid subsequent changes in anxiety and depression when individuals undergo heightened discrimination beyond their usual experiences. The study used 23 survey time points, primarily with 2-week intervals, from the Understanding America Study (n = 8198).

Social health, activity behaviors, and quality of life among young adult cancer survivors: Protocol for a prospective observational study.

Approximately 85,000 adolescent and young adults (AYAs; age 15-39) are diagnosed with cancer in the United States annually. Experiencing a cancer diagnosis as an AYA can substantially impact social connections and social health. This paper describes the design and protocol of an observational study to prospectively assess social health and its association with physical activity and quality of life among AYAs after a cancer diagnosis.

Association of Perceived Neighborhood Disorder with Substance Use Behaviors and Retail Access Among Southern California Adolescents.

Background: Neighborhood disadvantage is associated with a higher concentration of tobacco, cannabis and alcohol retailers and greater risk of certain substance use behaviors among youth. Less is known about the impact of subjective neighborhood disorder, which captures distinct exposures that may be relevant to substance use outcomes, including neighborhood social processes, safety, physical characteristics, and neighborhood drug use.

Methods: Data are from two waves (Feb-Dec 2022) of a prospective cohort of Southern California high school students ( = 2,139; mean[SD] age = 15.

Two Methods Based on Integral Equation Approaches in Analyzing Polyelectrolyte Solutions: Macrophase Separation.

To understand the phase behaviors of polyelectrolyte solutions, we provide two analytical methods to formulate a molecular equation of state for a system of fully charged polyanions (PAs) and polycations (PCs) in a monomeric neutral component, based on integral equation theories. The mixture is treated in a primitive and restricted manner. The first method utilizes Blum's approach to charged hard spheres, incorporating the chain connectivity contribution by charged spheres via Stell's cavity function method.

Social and clinical drivers of stress responses in African American breast cancer survivors.

Racial differences in breast cancer morbidity and mortality have been examined between Black/African American women and White women as part of efforts to characterize multilevel drivers of disease risk and outcomes. Current models of cancer disparities recognize the significance of physiological stress responses, yet data on stress hormones in Black/African American women with breast cancer and their social risk factors are limited. We examined cortisol levels in Black/African American breast cancer patients and tested their association with social and clinical factors to understand the relationship between stress responses and women's lived experiences.

Alcohol Use and Life Stressors During the COVID-19 Pandemic: A Longitudinal Study of Young Adults.

Objective: To estimate the extent to which drinking to cope with the COVID-19 pandemic and experiencing pandemic-related life stressors are associated with alcohol use escalation among young adults.

Methods: Respondents in Los Angeles, CA, USA (N=2,130) completed prospective cohort study surveys before (baseline; October 2018-November 2019; mean age: 19.7[SD=0.

Effects of mint, menthol, and tobacco-flavored e-cigarettes on tobacco withdrawal symptoms in adults who smoke menthol cigarettes: A laboratory pilot study.

Background: Menthol cigarette smoking has remained stable or increased in certain groups, despite an overall decline in cigarette smoking rates in the U.S. Understanding whether e-cigarettes alter patterns of menthol cigarette use is critical to informing efforts for reducing the public health burden of menthol cigarette smoking.

Characterizing Opioid Withdrawal Experiences and Consequences Among a Community Sample of People Who Use Opioids.

Background: Opioid withdrawal symptoms are a highly salient and consequential health condition experienced by people who use opioids (PWUO). This study utilized qualitative interviews to explore opioid withdrawal experiences and consequences among PWUO in Los Angeles County, USA.

Methods: Semi-structured qualitative interviews were conducted with 22 PWUO (aged 27-63 years) between May 2021 and May 2022.

Longitudinal Transitions Between Use of Combustible, Noncombustible, and Multiple Cannabis Products From Adolescence to Young Adulthood and Intersections With Nicotine Use.

Understanding transitions across use of different types of cannabis products and multiple cannabis products and how they intersect with nicotine use in young people can inform etiology and prevention. In this study, we examined transitions across use of combustible and noncombustible forms of cannabis and multiple types of cannabis from adolescence to young adulthood and the role of nicotine use in transitions. In a Southern California longitudinal cohort study (n = 3,298; baseline mean age = 16.

Nicotine deprivation amplifies attentional bias toward racial discrimination stimuli in African American adults who smoke cigarettes.

High smoking prevalence and low quit smoking rates among African American adults are well-documented, but poorly understood. We tested a transdisciplinary theoretical model of psychopharmacological-social mechanisms underlying smoking among African American adults. This model proposes that nicotine's acute attention-filtering effects may enhance smoking's addictiveness in populations unduly exposed to discrimination, like African American adults, because nicotine reduces the extent to which discrimination-related stimuli capture attention, and in turn, generate distress.

Effects of dual use of e-cigarette and cannabis during adolescence on cigarette use in young adulthood.

Introduction: E-cigarette and cannabis use by adolescents are risk factors for smoking initiation. We hypothesised that increasingly common dual use of e-cigarette and cannabis in adolescence leads to more frequent cigarette smoking in young adulthood.

Methods: Data are from a prospective cohort study in Southern California, where 1164 participants who ever used nicotine products in their lifetime completed surveys in 12th grade (T1:2016), and at 24-month (T2) and 42-month (T3) follow-ups.

Adolescent and Young Adult Response to Hypothetical E-Liquid Flavor Restrictions.

Objective: Rates of e-cigarette use among adolescents and young adults (AYAs) remain high despite several federal policy changes intended to limit their availability and appeal. The current study examined how restricting flavors would affect current AYA users' intentions to discontinue vaping, as a function of their current flavor preference.

Method: In a national cross-sectional survey, AYA e-cigarette users ( = 1,414) completed measures of e-cigarette use, device type, e-liquid flavor (tobacco, menthol, cool mint, fruit ice, fruit/sweet), and intent to discontinue e-cigarette use in response to hypothetical federal product standards (i.