Chiral Incommensurate Helical Phase in a Smectic of Achiral Bent-Core Mesogens.

An achiral, bent-core mesogen forms several tilted smectic liquid crystal phases, including a nonpolar, achiral de Vries smectic A which transitions to a chiral, ferroelectric state in applied electric fields above a threshold. At lower temperature, a chiral, ferrielectric phase with a periodic, supermolecular modulation of the tilt azimuth, indicated by a Bragg peak in carbon-edge resonant soft x-ray scattering, is observed. The absence of a corresponding resonant umklapp peak identifies the superlayer structure as a twist-bend-like helix that is only weakly modulated by the smectic layering.

Neighborhood environment and marijuana use in urban young adults.

Risk factors for marijuana use in older adolescents and young adults have focused primarily on family environment and peer affiliation. A growing body of work has examined the relationship between environmental context and young adult substance use. This study builds on previous research linking neighborhood environment to young adult marijuana use by exploring two distinct features of neighborhoods, namely the physical (e.g., broken windows) and social environment (e.g., adults watching youth). Data were obtained from a longitudinal sample of 398 predominately African American young adults living in an urban environment. The data also included observational measures of physical and social order and disorder collected on the young adult's residential block. Exploratory structural equation modeling (ESEM) was utilized to test hypothesized relationships between these two features of the neighborhood environment and past year young adult marijuana use. A two-factor model of neighborhood environment with good fit indices was selected (CFI = 0.97, RMSEA = 0.037). There was a positive and significant direct effect from neighborhood physical disorder to marijuana use (0.219, p < 0.05) controlling for gender, race, and free and reduced price meal (FARPM) status. The direct effect from neighborhood social environment to marijuana use was not significant. These results converge with previous research linking vacant housing with young adult marijuana use but do not provide empirical support for the neighborhood social environment as a determinant of drug taking. Better explication of the social environment is needed to understand its relationship to drug use.

Synthesis and structural data of tetrabenzo[8]circulene.

In 1976, the first attempted synthesis of the saddle-shaped molecule [8]circulene was reported. The next 37 years produced no advancement towards the construction of this complicated molecule. But remarkably, over the last six months, a flurry of progress has been made with two groups reporting independent and strikingly different strategies for the synthesis of [8]circulene derivatives. Herein, we present a third synthetic method, in which we target tetrabenzo[8]circulene. Our approach employs a Diels-Alder reaction and a palladium-catalyzed arylation reaction as the key steps. Despite calculations describing the instability of [8]circulene, coupled with the reported instability of synthesized derivatives of the parent molecule, the addition of four fused benzenoid rings around the periphery of the molecule provides a highly stable structure. This increased stability over the parent [8]circulene was predicted by using Clar's theory of aromatic sextets and is a result of the compound becoming fully benzenoid upon incorporation of these additional rings. The synthesized compound exhibits remarkable stability under ambient conditions-even at elevated temperatures-with no signs of decomposition over several months. The solid-state structure of this compound is significantly twisted compared to the calculated structure primarily as a result of crystal-packing forces in the solid state. Despite this contortion from the lowest-energy structure, a range of structural data is presented confirming the presence of localized aromaticity in this large polycyclic aromatic hydrocarbon.

Posttreatment drug use abstinence: does the majority program clientele matter?

The current study examines differences in organizational characteristics and client posttreatment drug use abstinence in residential substance abuse treatment programs serving clients with high or low levels of legal coercion to participate in treatment. The findings show that low legal coercion programs have higher counselor caseloads (Z = 59, p < .05) than high coercion programs. Although the results showed that programs with a large proportion of African American clients (ß = 14.26, p < .0001) and high legal coercion programs (ß = 19.99, p < .05) predicted longer abstinence posttreatment, the final models suggest organizational factors are the key predictors of client posttreatment abstinence.

Turning on lanthanide luminescence via nanoencapsulation.

Encapsulation of macrocyclic europium(III) chelates by discrete, monodisperse SiO2 nanoparticles (NPs) has been carried out, and the resulting significant enhancement of metal-derived luminescence has been studied to rationalize this dramatic effect. The tetraiminodiphenolate motif chosen for this study is easily synthesized and incorporated into the NP matrix under ambient conditions. The free complex exhibits primarily weak ligand-derived emission at room temperature, typical for these compounds, and displays intense metal-centered luminescence from the europium only when cooled to 77 K. Upon encapsulation by the NPs, however, europium-derived luminescence is visibly "turned on" at room temperature, yielding strong emission peaks characteristic of europium(III) with a corresponding enhancement factor of 6 × 10(6). The similar ligand singlet and triplet excited-state energies determined for the free complex (20820 and 17670 cm(-1), respectively) versus the encapsulated complex (20620 and 17730 cm(-1)) indicate that encapsulation does not affect the energy levels of the ligand appreciably. Instead, a detailed analysis of the metal-centered emission and ligand singlet and triplet emission bands for the free and encapsulated complexes reveals that the enhanced metal emission is due to the rigid environment afforded by the silica NP matrix affecting vibrationally mediated energy transfer. Further, the metal-centered emission lifetimes in methanol versus deuterated methanol indicate a decrease in the number of coordinated solvent molecules upon encapsulation, changing from an average of 3.3 to 2.1 bound methanol molecules and reducing the known quenching effect on europium-centered luminescence due to nearby OH vibrations.

Racial And Ethnic Disparities In Buprenorphine Receipt Among Medicare Beneficiaries, 2015-19.

We examined Medicare Part D claims from the period 2015-19 to identify state and national racial and ethnic disparities in buprenorphine receipt among Medicare disability beneficiaries with diagnosed opioid use disorder or opioid overdose. Racial and ethnic disparities in buprenorphine use remained persistently high during the study period, especially for Black beneficiaries, suggesting the need for targeted interventions and policies.

Silica microparticles as a solid support for gadolinium phosphonate magnetic resonance imaging contrast agents.

Particle-based magnetic resonance imaging (MRI) contrast agents have been the focus of recent studies, primarily due to the possibility of preparing multimodal particles capable of simultaneously targeting, imaging, and treating specific biological tissues in vivo. In addition, particle-based MRI contrast agents often have greater sensitivity than commercially available, soluble agents due to decreased molecular tumbling rates following surface immobilization, leading to increased relaxivities. Mesoporous silica particles are particularly attractive substrates due to their large internal surface areas. In this study, we immobilized a unique phosphonate-containing ligand onto mesoporous silica particles with a range of pore diameters, pore volumes, and surface areas, and Gd(III) ions were then chelated to the particles. Per-Gd(III) ionic relaxivities ranged from ∼2 to 10 mM(-1) s(-1) (37 °C, 60 MHz), compared to 3.0-3.5 mM(-1) s(-1) for commercial agents. The large surface areas allowed many Gd(III) ions to be chelated, leading to per-particle relaxivities of 3.3 × 10(7) mM(-1) s(-1), which is the largest value measured for a biologically suitable particle.

Jail-based treatment for opioid use disorder in the era of bail reform: a qualitative study of barriers and facilitators to implementation of a state-wide medication treatment initiative.

BACKGROUND: Until recently, few carceral facilities offered medications for opioid use disorder (MOUD). Although more facilities are adopting MOUD, much remains to be learned about addressing implementation challenges related to expansion of MOUD in carceral settings and linkage to care upon re-entry. This is particularly important in jails, where individuals cycle rapidly in and out of these facilities, especially in jurisdictions beginning to implement bail reform laws (i.e., laws that remove the requirement to pay bail for most individuals). Increasing access to MOUD in these settings is a key unexplored challenge. METHODS: In this qualitative study, we interviewed staff from county jails across New Jersey, a state that has implemented state-wide efforts to increase capacity for MOUD treatment in jails. We analyzed themes related to current practices used to engage individuals in MOUD while in jail and upon re-entry; major challenges to delivering MOUD and re-entry services, particularly under bail reform conditions; and innovative strategies to facilitate delivery of these services. RESULTS: Jail staff from 11 New Jersey county jails participated in a baseline survey and an in-depth qualitative interview from January-September 2020. Responses revealed that practices for delivering MOUD varied substantially across jails. Primary challenges included jails' limited resources and highly regulated operations, the chaotic nature of short jail stays, and concerns regarding limited MOUD and resources in the community. Still, jail staff identified multiple facilitators and creative solutions for delivering MOUD in the face of these obstacles, including opportunities brought on by the COVID-19 pandemic. CONCLUSIONS: Despite challenges to the delivery of MOUD, states can make concerted and sustained efforts to support opioid addiction treatment in jails. Increased use of evidence-based clinical guidelines, greater investment in resources, and increased partnerships with health and social service providers can greatly improve reach of treatment and save lives.

Racial disparities in substance abuse treatment and the ecological fallacy.

This study examined engagement in treatment in substance abuse treatment programs that treated primarily either African American or White clients. Findings showed higher levels of engagement in White programs; however, engagement of African Americans in White programs was similar to that of Whites and was greater than Whites in African American programs. No significant differences emerged when a mixed model analysis considered additional variables of staff consensus (regarding treatment elements), treatment climate, acceptance of Medicaid clients, the proportion mandated to treatment, and the quality of the physical space. Although African American programs may show poorer levels of engagement than White programs, attribution of engagement in treatment to client level race/ethnicity should be made with caution.

Adaptations to jail-based buprenorphine treatment during the COVID-19 pandemic.

Correctional facilities are among the highest-risk settings for the spread of COVID-19. Prior to the COVID-19 pandemic, the Hennepin County Jail in Minneapolis, Minnesota, offered short-term methadone maintenance, buprenorphine initiation and maintenance, and naltrexone initiation and maintenance to all jail residents with moderate to severe opioid use disorder (OUD). In response to the pandemic, the jail reduced its population by 43%. The reduced jail census and relaxed federal telemedicine regulations in response to the COVID-19 public health emergency declaration allowed the jail to institute modifications that permitted individuals to start buprenorphine without an initial in-person visit with a clinician. The jail also instituted a buprenorphine taper to bridge individuals to maintenance or provide withdrawal management, depending on patient preference. With a decreased jail census, the use of remote visits, and modifications to the buprenorphine treatment program, clinicians are able to meet the OUD treatment demand. Some jails may need additional funding streams to offset pandemic-related health treatment costs.

Performance of the CJDATS Co-Occurring Disorders Screening Instruments (CODSIs) among minority offenders.

Previous research has shown the performance of the CJDATS Co-Occurring Disorders Screening Instruments (CODSI-MD and SMD)--six- and three-item instruments to screen for any mental disorder (CODSI-MD) and for severe mental disorders (CODSI-SMD), respectively--to be comparable or superior to other, longer instruments. This study tested the stability of the performance of the CODSI-MD and SMD across three racial/ethnic groups of offenders entering prison substance abuse treatment programs (n = 353), consisting of 96 African American, 120 Latino, and 137 White admissions. The Structured Clinical Interview (SCID) was used to obtain DSM-IV Axis I and II diagnoses; a lifetime SCID diagnosis of a mental disorder or a severe mental disorder was the criterion against which the CODSI-MD and SMD were validated. Results showed no statistical differences in sensitivity or specificity for either the CODSI-MD or SMD across the African American, Latino, and White prisoner groups. The value of the CODSI-MD and SMD as brief screens for mental disorders among offenders with diverse racial/ethnic backgrounds is discussed.

Triangulating Syndemic Services and Drug Treatment Policy: Improving Drug Treatment Portal Locations in Baltimore City.

THE PROBLEM: The prevalence of injection drug use (IDU) and incidence of human immunodeficiency virus (HIV) remain high in Baltimore, where IDU is a primary HIV risk factor. Substance use disorders and HIV are related syndemically--their causes and consequences interact synergistically. Baltimore is increasingly considering the syndemic relationship of substance use disorders, IDU, and HIV in making decisions about drug treatment funding and location. PURPOSE OF ARTICLE: Our goal was to empirically identify the optimal location of new drug treatment programs through the development and application of a novel, practical tool. KEY POINTS: Syndemic triangles were constructed to measure and visualize unmet need for drug treatment services. These data were used to determine priority zones for new treatment centers. CONCLUSIONS: The application of this tool helped inform strategies for locating drug treatment services in Baltimore, and its successful use suggests its potential value in other metropolitan areas.

Latent class analysis of polysubstance use, sexual risk behaviors, and infectious disease among South African drug users.

BACKGROUND: HIV transmission risk among non-injection drug users is high due to the co-occurrence of drug use and sexual risk behaviors. The purpose of the current study was to identify patterns of drug use among polysubstance users within a high HIV prevalence population. METHODS: The study sample included 409 substance users from the Pretoria region of South Africa. Substances used by 20% or more the sample included: cigarettes, alcohol, marijuana and heroin in combination, marijuana and cigarettes in combination, and crack cocaine. Latent class analysis was used to identify patterns of polysubstance use based on types of drugs used. Multivariate logistic regression analyses compared classes on demographics, sexual risk behavior, and disease status. RESULTS: Four classes of substance use were found: MJ+Cig (40.8%), MJ+Her (30.8%), Crack (24.7%), and Low Use (3.7%). The MJ+Cig class was 6.7 times more likely to use alcohol and 3 times more likely to use drugs before/during sex with steady partners than the Crack class. The MJ+Cig class was 16 times more likely to use alcohol before/during sex with steady partners than the MJ+Her class. The Crack class was 6.1 times more likely to engage in transactional sex and less likely to use drugs before/during steady sex than the MJ+Her class. CONCLUSIONS: Findings illustrate patterns of drug use among a polysubstance using population that differ in sexual risk behavior. Intervention strategies should address substance use, particularly smoking as a route of administration (ROA), and sexual risk behaviors that best fit this high-risk population.

"Unplugged": a school-based randomized control trial to prevent and reduce adolescent substance use in the Czech Republic.

BACKGROUND: The Czech Unplugged Study, inspired by the European Drug Addiction Prevention Trial, is a prospective, school-based, randomized controlled prevention trial designed to reduce the risk of alcohol, tobacco, inhalant, and illegal drug use in 6th graders in the Czech Republic. The intervention uses the comprehensive social influence model to affect alcohol and drug using norms among primary school students. METHODS: Descriptive statistics and chi-square analyses were used to assess differences between the experimental and control groups on demographic characteristics and study outcomes. Multilevel techniques were used to take the hierarchical structure of the data into account. Prevalence odds ratios using the Bonferroni correction were calculated to assess the differences between the experimental (N = 914) and control (N = 839) groups on each outcome 1, 3, 12, 15, and 24 months after the end of the intervention. RESULTS: Multilevel analysis using the Bonferroni correction showed statistically significant intervention effects at the final follow-up for any smoking (OR = 0.75, 99.2% CI 0.65-0.87), daily smoking (OR = 0.62, 99.2% CI 0.48-0.79), heavy smoking (OR = 0.48, 99.2% CI 0.28-0.81), any cannabis use (OR = 0.57 99.2% CI 0.42-0.77), frequent cannabis use (OR = 0.57, 99.2% CI 0.36-0.89), and any drug use (OR = 0.78, 99.2% CI 0.65-0.94). CONCLUSIONS: This study adds new evidence on the effectiveness of the Unplugged school-based prevention program for primary school students in the Czech Republic.

Sex specific trajectories in cigarette smoking behaviors among students participating in the unplugged school-based randomized control trial for substance use prevention.

OBJECTIVES: Understanding the developmental pathways and sex differences in cigarette smoking behaviors in adolescents has the potential to positively impact substance abuse prevention and to reduce smoking-related health problems. Using data from the Unplugged school-based prevention trial, we investigated different patterns of smoking behavior development among secondary school students in the Czech Republic. METHODS: Growth mixture modeling was used to examine different trajectories in cigarette smoking behaviors among male and female students (N=1874 6th graders; 50.4% male, mean age 11.8 years at baseline) participating in the Unplugged school-based randomized control trial for substance use prevention. RESULTS: A two-class model characterized cigarette use as a function of sex and Unplugged intervention status. More rapid cigarette use increases were observed in females (OR=1.17, p=0.01 in both rapid/moderate and slow smoking escalator classes) as compared to males. Further, in both classes, more rapid increases in smoking were observed for the control group as compared to the intervention group (OR=1.22, p<0.01 slow escalators; OR=1.54, p=0.08 rapid/moderate escalators). There was no difference in sex distribution when comparing the two classes (OR=1.02, p=0.98). CONCLUSIONS: This study adds to a growing literature on developmental and sex differences in cigarette use among adolescents. This research supports additional multi-year prevention strategies aimed at adolescent females and early treatment programs for adolescent smokers to prevent increasing cigarette use with age.

Gender Power Inequality and Continued Sexual Risk Behavior among Racial/Ethnic Minority Adolescent and Young Adult Women Living with HIV.

Adolescent and young adult minority women account for approximately 20% of new cases of HIV in this age group each year in the United States. It is vital to understand factors that influence sexual risk behavior in this population in order to prevent secondary transmission of HIV. As part of a larger qualitative study of youths living with HIV, in- depth interviews were conducted with 26 Black and Latina young women aged 16 to 24 years, infected with HIV through heterosexual transmission. The study explored factors related to continued unprotected sex with male partners. Since learning of their HIV infection, 23% reported multiple episodes of unprotected vaginal and/or anal sex, 27% reported condom use for some but not all of the time, 42% reported condom use all of the time and 7% were not sexually active. Among the highest risk participants partner refusal to use a condom, having the same HIV sero-status as partner, negative attitudes toward condoms, beliefs about HIV transmission, and fear of disclosure to new partners were associated with risky sex. The data suggests that more research is needed to develop more intensive interventions that address the role of gender power inequity for this sub-set of young women living with HIV.

Continued Sexual Risk Behaviour in African American and Latino Male-to-Female Transgender Adolescents Living with Hiv/Aids: A Case Study.

PURPOSE: This study examined the social and contextual factors associated with continued high risk sexual behaviors among male-to-female transgender (MTFTG) adolescents living with HIV/AIDS. The study is part of a larger qualitative study of 59 racial/ethnic minority adolescents living with HIV/AIDS. METHODS: In-depth focused interviews were conducted with five MTFTG adolescents (16-24 years) living with HIV. Content analysis was conducted to identify themes related to continued sexual risk behaviors. RESULTS: Four out of five of MTFTG adolescents reported inconsistent condom use since their HIV diagnosis. Transgender stigma contributed to financial vulnerability leading to the adoption of sex work to support themselves. Sex and drugs were used to manage transgender stigma and sexual risk-taking with sex work partners was influenced by financial vulnerability. CONCLUSIONS: MTFTG adolescents with HIV have unique psychosocial needs related to transgender stigma and structural needs to decrease financial vulnerability that contribute to risky sexual behavior.

The influence of substance use, social sexual environment, psychosocial factors, and partner characteristics on high-risk sexual behavior among young Black and Latino men who have sex with men living with HIV: A qualitative study.

Understanding the sexual risk behaviors of youths living with HIV/AIDS is critical to secondary prevention of HIV. As part of a larger qualitative study of youths living with HIV, in-depth interviews were conducted with 27 African American and Latino, HIV-infected young men who have sex with men, aged 16-24 years, living in New York City. The study explored the role of substance use, the social-sexual-environmental, and psychological contexts in which sexual risk behaviors occurred. Since learning of their HIV infection, the majority of participants had reduced their risky sexual behaviors; however, a subset (26%) of participants continued to have unprotected sex, in most cases with multiple partners. Substance use, the social environmental context of the sexual encounter, the psychological impact of HIV on sexual behavior, and partner characteristics were associated with high-risk sexual behaviors in this group. Among high-risk participants, factors associated with risky sexual behaviors clustered, with 57% reporting two or more factors. More intensive interventions are needed for this subset of youths living with HIV, including assessment and treatment for substance use and mental health issues, strategies for stress reduction, and partner interventions.