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1.
Behav Med ; : 1-10, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38618978

RESUMEN

Although socioeconomic status (SES) is fundamentally related to underutilization of colorectal cancer (CRC) screening, the role of perceived economic strain and subjective social status with CRC screening is understudied. The aim of this study was to investigate whether greater perceived economic strain or lower subjective social status would decrease the odds of CRC screening uptake and being up-to-date with guideline-recommended CRC screening. We also explored interactions with household income and educational attainment. Cross-sectional survey-based data from men aged 45-75 years living in the United States (N = 499) were collected in February 2022. Study outcomes were ever completing a stool- or exam-based CRC screening test and being up-to-date with CRC screening. Perceived economic strain and subjective social status were the predictors. We conducted logistic regression models to estimate odds ratios (OR) and 95% confidence intervals (CI). Greater perceptions of economic strain decreased odds of being up-to-date with CRC screening. Household income modified the association between perceived economic strain and completing a stool-based test; the association was stronger for men from lower-income households. In unadjusted models, higher subjective social status increased odds of completing an exam-based test and being up-to-date with CRC screening. Our findings suggest that experiencing economic strain may interfere with men's CRC screening decisions and may capture additional information about barriers to CRC screening utilization beyond those captured by income or education.

2.
Cancer Causes Control ; 34(9): 737-747, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37243849

RESUMEN

PURPOSE: To examine whether a greater perception of economic pressure would be associated with more-negative attitudes, greater perceived barriers, and lower subjective norms regarding colorectal cancer (CRC) and CRC screening among males aged 45-75 years. METHODS: We recruited 492 self-identified males aged 45-75 years living in the United States. We operationalized perceived economic pressure as a latent factor with three subscales: can't make ends meet, unmet material needs, and financial cutbacks. Our dependent variables were attitudes toward CRC and CRC screening, perceived barriers to completing a CRC screening exam, and subjective norms regarding CRC screening (e.g., how others value CRC screening). We tested a hypothesized model using structural equation modeling with maximum-likelihood estimation, adjusting for covariates, and made post-hoc modifications to improve model fit. RESULTS: Greater perceived economic pressure was associated with more-negative attitudes toward CRC and CRC screening (ß = 0.47, 95% CI: 0.37,0.57) and with greater perceived barriers to CRC screening (ß = 0.22, 95% CI: 0.11, 0.34), but was not significantly associated with subjective norms (ß = 0.07, 95% CI: - 0.05, 0.19). Perceived economic pressure was an indirect pathway by which lower-income and younger age were associated with more-negative attitudes and greater perceived barriers. CONCLUSIONS: Our study is one of the first to show that, among males, perceived economic pressure is associated with two social-cognitive mechanisms (i.e., negative attitudes, greater perceived barriers) that are known to influence CRC screening intent and, ultimately, CRC screening completion. Future research on this topic should employ longitudinal study designs.


Asunto(s)
Neoplasias Colorrectales , Conocimientos, Actitudes y Práctica en Salud , Masculino , Humanos , Estados Unidos/epidemiología , Estudios Longitudinales , Neoplasias Colorrectales/diagnóstico , Neoplasias Colorrectales/epidemiología , Neoplasias Colorrectales/prevención & control , Intención , Detección Precoz del Cáncer/psicología , Tamizaje Masivo
3.
Surg Endosc ; 37(5): 3306-3320, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-36520224

RESUMEN

BACKGROUND: Some studies have suggested disparities in access to robotic colorectal surgery, however, it is unclear which factors are most meaningful in the determination of approach relative to laparoscopic or open surgery. This study aimed to identify the most influential factors contributing to robotic colorectal surgery utilization. METHODS: We conducted a systematic review and random-effects meta-analysis of published studies that compared the utilization of robotic colorectal surgery versus laparoscopic or open surgery. Eligible studies were identified through PubMed, EMBASE, CINAHL, Cochrane CENTRAL, PsycINFO, and ProQuest Dissertations in September 2021. RESULTS: Twenty-nine studies were included in the analysis. Patients were less likely to undergo robotic versus laparoscopic surgery if they were female (OR = 0.91, 0.84-0.98), older (OR = 1.61, 1.38-1.88), had Medicare (OR = 0.84, 0.71-0.99), or had comorbidities (OR = 0.83, 0.77-0.91). Non-academic hospitals had lower odds of conducting robotic versus laparoscopic surgery (OR = 0.73, 0.62-0.86). Additional disparities were observed when comparing robotic with open surgery for patients who were Black (OR = 0.78, 0.71-0.86), had lower income (OR = 0.67, 0.62-0.74), had Medicaid (OR = 0.58, 0.43-0.80), or were uninsured (OR = 0.29, 0.21-0.39). CONCLUSION: When determining who undergoes robotic surgery, consideration of factors such as age and comorbid conditions may be clinically justified, while other factors seem less justifiable. Black patients and the underinsured were less likely to undergo robotic surgery. This study identifies nonclinical disparities in access to robotics that should be addressed to provide more equitable access to innovations in colorectal surgery.


Asunto(s)
Cirugía Colorrectal , Procedimientos Quirúrgicos del Sistema Digestivo , Laparoscopía , Procedimientos Quirúrgicos Robotizados , Robótica , Humanos , Femenino , Anciano , Estados Unidos , Masculino , Medicare
4.
Psychol Men Masc ; 24(2): 103-112, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37193560

RESUMEN

Receptivity to recommended colorectal cancer (CRC) screening can be enhanced by use of loss-framed health messaging that emphasizes possible consequences of failing to act. However, a simultaneous use of culturally targeted messaging may be needed to achieve effectiveness when loss-framed messaging is used with African Americans, especially to reduce racism-related cognitions aroused by standard loss framing that impede CRC screening receptivity. This study considered whether effects of stand-alone and culturally targeted message framing on CRC screening receptivity differ between African American men and women. African Americans eligible for CRC screening (Men=117, Women=340) viewed an informational video about CRC risks, prevention, and screening, and were randomized to receive a gain or loss-framed message about screening. Half of participants received an additional culturally targeted message. Using the Theory of Planned Behavior, we measured receptivity to CRC screening. We also measured arousal of racism-related cognitions. A significant three-way interaction suggested effects of messaging on CRC screening receptivity were moderated by gender. Participants were no more receptive to CRC screening when standard loss-framing was used, but were more favorable if loss-framing was culturally targeted. However, these effects were more pronounced among African American men. Contrary to prior findings, gender moderated effects of culturally targeted loss-framed messaging were not attributable to reducing racism-related cognitions. Findings add to growing recognition of important nuance in effective use of message framing to also include gender, while suggesting a critical need to explore gender-relevant mechanistic pathways, potentially including how health messaging activates masculinity-related cognitions among African American men.

5.
Oncologist ; 27(4): 285-291, 2022 04 05.
Artículo en Inglés | MEDLINE | ID: mdl-35380723

RESUMEN

While hereditary cancer syndromes have been described and studied for centuries, the completion of the human genome project fueled accelerated progress in precision medicine due to the introduction of genetic testing in the 1990s, creating avenues for tailored treatments and medical management options. However, genetic testing has not benefited everyone equitably, with nearly all of the published work based on individuals of non-Hispanic White/European ancestry. There remains a gap in knowledge regarding the prevalence, penetrance, and manifestations of common hereditary cancer syndromes in the African-American population due to significant disparities in access and uptake of genetic testing. This review summarizes the available literature on genetic testing for breast, colon, and prostate cancers in the African-American population and explores the disparities in access to genetic testing between non-Hispanic White and African-American patients. This article also addresses the barriers to genetic testing and discrepancies in the uptake of recommendations for hereditary cancer syndromes in the African-American population when compared with non-Hispanic Whites. The review offers practice implications for many healthcare providers and demonstrates gaps in the existing knowledge to be addressed in future studies to help eliminate the persisting health disparities faced by the African-American population.


Asunto(s)
Síndromes Neoplásicos Hereditarios , Neoplasias de la Próstata , Negro o Afroamericano/genética , Pruebas Genéticas , Humanos , Masculino , Síndromes Neoplásicos Hereditarios/epidemiología , Síndromes Neoplásicos Hereditarios/genética , Neoplasias de la Próstata/genética , Población Blanca
6.
Ethn Health ; 27(5): 1103-1122, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-33249920

RESUMEN

OBJECTIVES: Despite having the highest colorectal cancer (CRC) incidence and mortality across all major racial/ethnic groups, African-American men consistently have poor CRC screening rates. Gendered and racialized beliefs and norms have been associated with African-American men's lower medical assistance-seeking rates, but how these notions influence African-American men's CRC screening practices merits further investigation. The purpose of this study was to examine the influence of psychosocial determinants of men's health on CRC screening uptake among African-American men in three states. DESIGN: Participants were recruited via CuttingCRC.com and through culturally-tailored flyers, newspaper ads, and snowball sampling, among other methods. From April 2019-August 2019, 11 focus groups were conducted with English-speaking Black/African-American men who (a) were between ages 45-75, (b) were born in the United States, (c) had a working telephone, and (d) lived in Minnesota, Ohio, or Utah. Multiple-cycle coding, Hatch's 9-step approach, and constant comparative data analysis was employed for de-identified transcript data. RESULTS: Eighty-four African-American men met inclusion criteria and participated. Their mean age was 59.34 ± 7.43. In regards to CRC screening status, Ohio had the most previously screened participants (85%), followed by Minnesota (84%) and Utah (76%). Two major CRC screening barriers (masculine role norms and medical mistrust) - both encompassed 3-5 subthemes, and one major facilitator (normative support from family members or social networks) emerged. CONCLUSIONS: Despite CRC screening's life-saving potential, African-American men have had the lowest 5-year relative survival for more than 40 years. When developing interventions and health promotion programs aiming to eliminate the racial disparity in CRC outcomes, addressing both masculine role norms and medical mistrust barriers to CRC screening completion among African-American men is warranted.


Asunto(s)
Neoplasias Colorrectales , Detección Precoz del Cáncer , Negro o Afroamericano/psicología , Anciano , Neoplasias Colorrectales/prevención & control , Detección Precoz del Cáncer/psicología , Humanos , Masculino , Salud del Hombre , Persona de Mediana Edad , Confianza , Estados Unidos
7.
Am J Obstet Gynecol ; 224(6): 591.e1-591.e12, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33412131

RESUMEN

BACKGROUND: Women with polycystic ovary syndrome are more likely to experience several pregnancy complications including hypertensive disorders, gestational diabetes mellitus, and preterm births than women without polycystic ovary syndrome. However, at present, there is limited research on whether polycystic ovary syndrome is associated with both anxiety and depression during pregnancy and whether this augments a woman's risk of postpartum depression, particularly among high-risk populations who have limited access to care. OBJECTIVE: Our primary objective was to assess the association between prepregnancy polycystic ovary syndrome and postpartum depression, considering important baseline confounding factors. Our secondary objective was to evaluate the mediating role of prenatal depression and anxiety on the association between polycystic ovary syndrome and postpartum depression. STUDY DESIGN: This study involved a population-based sample of 3906 postpartum (2-6 months) women who completed the Utah Pregnancy Risk Assessment Monitoring System Phase 8 questionnaire (2016-2018). Weighted adjusted prevalence ratios were used to assess the association between polycystic ovary syndrome and postpartum depression, considering potential confounding factors and assessing mediating effects of depression and anxiety experienced during pregnancy. RESULTS: Following the exclusion criteria, 8.2% of women reported clinical polycystic ovary syndrome and 19.1%, 6.2%, and 4.4% reported irregular periods and acne, irregular periods and hirsutism, and all 3 symptoms, respectively. Moreover, 17.7% and 23.5% reported experiencing prenatal depression and anxiety and 9.5% and 10.2% reported experiencing postpartum depressed mood and anhedonia, respectively. Clinical polycystic ovary syndrome was associated with a 1.76 higher adjusted prevalence ratio (95% confidence interval, 1.03-3.00) for postpartum depressed mood or anhedonia after taking into consideration age, prepregnancy body mass index, race/ethnicity, education, and marital status. A similar higher prevalence was seen for irregular periods and acne (adjusted prevalence ratio, 1.65; 95% confidence interval, 1.13-2.41), irregular periods and hirsutism (adjusted prevalence ratio, 1.40; 95% confidence interval, 0.82-2.40), and all 3 symptoms (adjusted prevalence ratio, 1.75; 95% confidence interval, 0.96-3.19) and postpartum depressed mood or anhedonia. Prenatal depression and anxiety mediated 20% and 32% of the effect of clinical polycystic ovary syndrome on postpartum depressed mood and anhedonia, respectively. CONCLUSION: Clinical polycystic ovary syndrome is associated with postpartum depressed mood and symptoms among this population-based sample inclusive of high-risk mothers. Prenatal depression and anxiety mediate this association, emphasizing the importance of prenatal psychological screening among women with polycystic ovary syndrome. An additional important clinical and public health implication of this study lies in the finding that nearly 20% of women in this population-based sample who reported at least 2 polycystic ovary syndrome symptoms (including at-risk women who may not have access to care) had not received a clinical diagnosis for polycystic ovary syndrome.


Asunto(s)
Depresión Posparto/etiología , Síndrome del Ovario Poliquístico/complicaciones , Adolescente , Adulto , Ansiedad/complicaciones , Ansiedad/epidemiología , Estudios Transversales , Depresión Posparto/diagnóstico , Depresión Posparto/epidemiología , Femenino , Humanos , Persona de Mediana Edad , Síndrome del Ovario Poliquístico/psicología , Embarazo , Complicaciones del Embarazo/epidemiología , Complicaciones del Embarazo/psicología , Prevalencia , Estudios Retrospectivos , Factores de Riesgo , Autoinforme , Adulto Joven
8.
Ethn Health ; 26(2): 168-185, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-29973057

RESUMEN

The rate of cancer screening is generally increasing in the US. In Minnesota, the statewide average rate of screening for colorectal cancer (CRC) is 73%. However, screening completion is relatively low among Somali men; overall, only 27% of Somali immigrants have been screened for CRC. Factors contributing to this disparity have not been well researched. The purpose of this pilot study was to employ focus group methodology to describe and advance understanding of the barriers and enablers associated with CRC screening among Somali men ages 50-74 in Minnesota. Three focus groups were conducted among 27 Somali men in Minnesota. A 9-question, semi-structured interview guide was used. The sessions were audio recorded, transcribed verbatim, and checked for accuracy by research staff prior to data analysis. Three research team members utilized the constant comparative method and NVivo to conduct data analysis. Five barriers to CRC screening emerged from the analyses: (1) lack of knowledge, (2) emotional barriers, (3) acculturation, (4) accountability, and (5) fatalistic beliefs. In addition, two factors enabling CRC screening and prevention emerged: the need for tailored interventions and preventive lifestyle behaviors. The insights gained from this research will assist in developing health promotion and education-focused interventions that encourage Somali immigrants in Minnesota and beyond to seek early detection screening for CRC.Abbreviations: CRC: Colorectal Cancer; FIT: Fecal Immunochemical Test; FOBT: Fecal Occult Blood Test; FQHC: Federally Qualified Health Center; PA: Project Assistant; PI: Principal Investigator.


Asunto(s)
Neoplasias Colorrectales , Detección Precoz del Cáncer , Anciano , Neoplasias Colorrectales/diagnóstico , Humanos , Masculino , Tamizaje Masivo , Persona de Mediana Edad , Minnesota , Proyectos Piloto , Somalia
9.
J Am Chem Soc ; 142(20): 9337-9351, 2020 05 20.
Artículo en Inglés | MEDLINE | ID: mdl-32330034

RESUMEN

Using solid-state 15N NMR spectroscopy, the cis/trans isomerization in a two-dimensional (2-D) array of surface-mounted azobenzene-based switches was detected for the first time. In order to achieve this, a new class of rod-shaped molecular switches, suitable for formation of 2-D regular arrays on large facets of tris(o-phenylenedioxy)cyclotriphosphazene (TPP) nanocrystals, was synthesized. A mechanochemical approach was used to prepare corresponding host-guest surface inclusions in a TPP matrix. Comparison of thermal steps in solution and supramolecular surface inclusions revealed that switching of individual molecules is not compromised by the close proximity of neighbors.

10.
Cancer Causes Control ; 31(3): 241-253, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32002718

RESUMEN

Rural areas of the U.S. experience disproportionate colorectal cancer (CRC) death compared to urban areas. The authors aimed to analyze differences in CRC survival between rural and urban Utah men and investigate potential prognostic factors for survival among these men. A cohort of Utah men diagnosed with CRC between 1997 and 2013 was identified from the Utah Cancer Registry. Survival and prognostic factors were analyzed via 5-year CRC survival and Cox proportional hazards models, stratified by rural/urban residence. Among 4,660 men diagnosed with CRC, 15.3% were living in rural Utah. Compared with urban men, rural CRC patients were diagnosed at older ages and in different anatomic subsites; more were overweight, and current smokers. Differences in stage and treatment were not apparent between rural and urban CRC patients. Compared with urban counterparts, rural men experienced a lower CRC survival (Hazard Ratio 0.55, 95% CI 0.53, 0.58 vs. 0.58, 95% CI 0.56, 0.59). Race and cancer treatment influenced CRC survival among men living in both urban and rural areas. Factors of CRC survival varied greatly among urban and rural men in Utah. The influence of social and environmental conditions on health behaviors and outcomes merits further exploration.


Asunto(s)
Neoplasias Colorrectales/mortalidad , Sistema de Registros , Población Rural/estadística & datos numéricos , Población Urbana/estadística & datos numéricos , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Neoplasias del Colon , Neoplasias Colorrectales/etnología , Disparidades en Atención de Salud , Humanos , Masculino , Persona de Mediana Edad , Modelos de Riesgos Proporcionales , Riesgo , Utah/epidemiología
11.
J Org Chem ; 84(13): 8449-8467, 2019 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-31132268

RESUMEN

A new generation of double pyridazine molecular rotors differing in intramolecular dipole-dipole spacing was synthesized. All rotor molecules formed bulk inclusions in a tris( o-phenylenedioxy)cyclotriphosphazene (TPP) host. Results of dielectric spectroscopy were fitted to a pair of nine-state models that accounted for interactions of neighboring dipoles at either an aligned or opposed possible orientation of the local threefold dipole rotation potentials within a channel of the TPP host. The results indicate dipole-dipole interaction strengths at the 100 to 200 K scale that lead dipoles to preferentially populate a subset of low-energy configurations. They also reveal that pyridazines with ethynyl substituents in 3- and 6-positions have slightly higher rotational barriers (3.2-3.5 kcal/mol) than those carrying one ethynyl and one tert-butyl group (1.9-3.0 kcal/mol). Upon cooling, these barriers reduce the rate of thermal transitions between the potential wells so much that the inclusions cannot achieve ordered dipolar ground states.

12.
J Cancer Educ ; 34(3): 446-454, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-29430610

RESUMEN

The study aims to explore variation in scholarly productivity outcomes by underrepresented status among a diverse sample of researchers in a community-engaged training program. We identified 141 trainees from a web-based survey of researchers in the National Cancer Institute-funded, Community Networks Program Centers (CNPCs) (2011-2016). We conducted a series of multiple logistic regression models to estimate the effect of National Institutes of Health (NIH)-defined underrepresented status on four, self-reported, scholarly productivity outcomes in the previous 5 years: number of publications (first-authored and total) and funded grants (NIH and any agency). Sixty-five percent (n = 92) indicated NIH underrepresented status. In final adjusted models, non-NIH underrepresented (vs. underrepresented) trainees reported an increased odds of having more than the median number of total publications (> 9) (OR = 3.14, 95% CI 1.21-8.65) and any grant funding (OR = 5.10, 95% CI 1.77-14.65). Reporting ≥ 1 mentors (vs. none) was also positively associated (p < 0.05) with these outcomes. The CNPC underrepresented trainees had similar success in first-authored publications and NIH funding as non-underrepresented trainees, but not total publications and grants. Examining trainees' mentoring experiences over time in relation to scholarly productivity outcomes is needed.


Asunto(s)
Redes Comunitarias/organización & administración , Disparidades en el Estado de Salud , Tutoría/métodos , Grupos Minoritarios/estadística & datos numéricos , Neoplasias/etnología , Investigadores/educación , Apoyo a la Formación Profesional/métodos , Adulto , Investigación Biomédica/educación , Femenino , Humanos , Masculino , Persona de Mediana Edad , National Cancer Institute (U.S.) , National Institutes of Health (U.S.) , Apoyo a la Investigación como Asunto/estadística & datos numéricos , Encuestas y Cuestionarios , Estados Unidos
13.
J Am Chem Soc ; 139(30): 10486-10498, 2017 08 02.
Artículo en Inglés | MEDLINE | ID: mdl-28654753

RESUMEN

A new unidirectional light-driven molecular motor suitable for host-guest surface inclusion complexes with tris(o-phenylene)cyclotriphosphazene (TPP) was synthesized. The motor molecules formed regular two-dimensional trigonal arrays covering the large facets of disc-shaped TPP nanocrystals. Photochemical and thermal isomerization studies demonstrated that the light-driven rotation of the anchored motors is similar to that observed in solution and is not compromised neither by either the surface confinement or the density of surface coverage (50 vs 100%).

14.
Subst Use Misuse ; 51(10): 1393-7, 2016 08 23.
Artículo en Inglés | MEDLINE | ID: mdl-27267588

RESUMEN

BACKGROUND: Tobacco use is higher among homeless individuals than the general population. Homeless individuals are also more likely to have symptoms of depression. Depression symptoms may add to the burden of homelessness by increasing psychological distress and serve as a barrier to quitting smoking. OBJECTIVES: The primary goal of this study is to assess the impact of depression symptoms on psychological distress in homeless smokers. The effect of depression symptoms on abstinence and the effect of Motivational Interviewing (MI) on cessation among smokers is also explored. METHODS: Homeless smokers (N = 430) enrolled in a smoking cessation study were randomized to Motivational Interviewing (MI) or standard care (SC). Participants received nicotine replacement therapy and were followed for 26 weeks. Participants were categorized into a depression symptoms (DS) group or control group using the Patient Health Questionnaire-9. Between group differences of perceived stress, hopelessness, confidence, craving and abstinence were assessed at weeks 8 and 26. The interaction between depression symptoms (levels: DS and control) and the intervention (levels: MI and SC) was also assessed. RESULTS: Homeless smokers in the DS group reported higher levels of hopelessness, perceived stress, and craving. There was no effect of DS status on abstinence at week 8 or week 26. There was no significant interaction between depression symptoms (DS vs. Control) and the intervention (MI vs. SC). CONCLUSION: Despite reporting greater psychological distress, homeless smokers with depression symptoms in this sample had abstinence levels similar to the control group. Future research should explore protective factors among depressed smokers.


Asunto(s)
Entrevista Motivacional , Depresión , Personas con Mala Vivienda , Humanos , Fumadores , Cese del Hábito de Fumar
15.
J Pastoral Care Counsel ; 70(1): 5-15, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26956745

RESUMEN

This study advances the work of developing a theory for educating Clinical Pastoral Education (CPE) Supervisors by describing the behaviors which result from the successful completion of CPE supervisory education. Twenty-eight Association for Clinical Pastoral Education (ACPE) Certification Commissioners were interviewed to identify the behaviors demonstrated by Supervisory Education Students (Candidates) which influenced the decision to certify them at the level of Associate Supervisor. Specific behavioral descriptors are listed for each ACPE supervisory competency.


Asunto(s)
Servicio de Capellanía en Hospital/organización & administración , Competencia Clínica , Educación Profesional/organización & administración , Mentores/educación , Cuidado Pastoral/educación , Humanos , Liderazgo , Competencia Profesional , Investigación Cualitativa , Estados Unidos
16.
J Org Chem ; 80(12): 6173-92, 2015 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-25946511

RESUMEN

A new generation of rod-shaped dipolar molecular rotors designed for controlled insertion into channel arrays in the surface of hexagonal tris(o-phenylenedioxy)cyclotriphosphazene (TPP) has been designed and synthesized. Triptycene is used as a stopper intended to prevent complete insertion, forcing the formation of a surface inclusion. Two widely separated (13)C NMR markers are present in the shaft for monitoring the degree of insertion. The structure of the two-dimensional rotor arrays contained in these surface inclusions was examined by solid-state NMR and X-ray powder diffraction. The NMR markers and the triptycene stopper functioned as designed, but half of the guest molecules were not inserted as deeply into the TPP channels as the other half. As a result, the dipolar rotators were distributed equally in two planes parallel to the crystal surface instead of being located in a single plane as would be required for ferroelectricity. Dielectric spectroscopy revealed rotational barriers of ∼4 kcal/mol but no ferroelectric behavior.

17.
Angew Chem Int Ed Engl ; 54(16): 4773-7, 2015 Apr 13.
Artículo en Inglés | MEDLINE | ID: mdl-25689486

RESUMEN

New mesoporous covalent frameworks, based on hybrid fluorinated organosilicas, were prepared to realize a periodic architecture of fast molecular rotors containing dynamic dipoles in their structure. The mobile elements, designed on the basis of fluorinated p-divinylbenzene moieties, were integrated into the robust covalent structure through siloxane bonds, and showed not only the rapid dynamics of the aromatic rings (ca. 10(8) Hz at 325 K), as detected by solid-state NMR spectroscopy, but also a dielectric response typical of a fast dipole reorientation under the stimuli of an applied electric field. Furthermore, the mesochannels are open and accessible to diffusing in gas molecules, and rotor mobility could be individually regulated by I2 vapors. The iodine enters the channels of the periodic structure and reacts with the pivotal double bonds of the divinyl-fluoro-phenylene rotors, affecting their motion and the dielectric properties.

18.
Top Curr Chem ; 354: 163-211, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24563012

RESUMEN

Regular two-dimensional or three-dimensional arrays of mutually interacting dipolar molecular rotors represent a worthy synthetic objective. Their dielectric properties, including possible collective behavior, will be a sensitive function of the location of the rotors, the orientation of their axes, and the size of their dipoles. Host-guest chemistry is one possible approach to gaining fine control over these factors. We describe the progress that has been achieved in recent years using tris (o-phenylenedioxy)cyclotriphosphazene as a host and a series of rod-shaped dipolar molecular rotors as guests. Structures of both surface and bulk inclusion compounds have been established primarily by solid-state nuclear magnetic resonance (NMR) and powder X-ray diffraction (XRD) techniques. Low-temperature dielectric spectroscopy revealed rotational barriers as low as 1.5 kcal/mol, but no definitive evidence for collective behavior has been obtained so far.

19.
Am J Cancer Res ; 14(1): 182-191, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38323294

RESUMEN

The increase of early-onset colorectal cancer (CRC) among younger adults is a major public health concern. However, little is known about variations in CRC incidence across different age groups within small geographic areas in Georgia. We examined temporal trends of CRC incidence in Clayton, East Central, West Central, Northeast, and Southeast regions, by age groups. Annual incidence rates for CRC in individuals aged 15+ years during 2000-2020 in the five regions of Georgia were included. Temporal trends were examined within the five regions and stratified by age group. Joinpoint regression was employed to calculate the annual percent change and corresponding 95% confidence intervals (CIs). Among 20,215 CRC diagnoses, CRC incidence declined over time for East Central (-2.33%; 95% CI, -3.03, -1.64), Northeast (-1.63%; 95% CI, -2.15, -1.04), Southeast (-1.63%; 95% CI, -2.30, -0.96), and West Central (-1.53%; 95% CI, -2.04, -1.03) Georgia. In the 15-44 age group, a notable increase of CRC incidence was found in Clayton, Northeast, and Southeast regions with a range of 2.2%-3.4%. However, adults aged 60+ years experienced a significant decrease in CRC incidence for most Georgia regions (all p-value <0.05), except for the Clayton region. In conclusion, CRC incidence declined during 2000-2020 in most Georgia regions. However, early-onset CRC is a major concern in Georgia as young adults (<45 years) living in Clayton, Northeast, and Southeast Georgia experienced significant annual increases in CRC incidence. Targeted CRC screening and awareness campaigns should be prioritized for adults <45 years and in the most impacted areas in Georgia.

20.
Chem Commun (Camb) ; 60(8): 960-963, 2024 Jan 23.
Artículo en Inglés | MEDLINE | ID: mdl-37955197

RESUMEN

Dielectric spectroscopy has been used to determine the barriers of rotation of surface-mounted fullerenes (2.3 ± 0.1 and 4.3 ± 0.1 kcal mol-1). In order to achieve this, a C60 derivative equipped with an anchoring group designed to form a surface inclusion with the hexagonal form of tris(o-phenylenedioxy)cyclotriphosphazene (TPP) has been synthesized. Solid-state NMR analysis revealed that approximately 50% of the surface-mounted molecules have a chemical environment different from the others suggesting two distinct insertion modes. These observations correlate with results of DFT calculations.

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