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1.
J Cancer Educ ; 38(2): 467-475, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-35112296

RESUMO

Ideal efforts for cancer prevention would include lifestyle modifications along with routine, age-eligible cancer screening. Employing an asset-based approach within vulnerable populations already engaging in at least one healthy behavior (i.e., physical activity) may be an ideal way to further reduce cancer risk across peer groups with low cancer screening rates. Guided by the theory of planned behavior (TPB), the aim of this study was to identify constructs associated with cancer screening intentions among young to middle aged adults for influencing educational and behavioral interventions designed to promote cancer prevention. A cross-sectional, web-based survey was utilized to assess attitudes, subjective norms, perceived behavioral control, and intention to screen for cancer among physically active adults aged 18-49 years. Descriptive and bivariate analyses were conducted to characterize the sample, and hierarchical linear regression analyses were conducted to assess the influence of sociodemographic variables and TPB constructs on cancer screening intentions. Age, female sex, reporting a routine doctor's visit, reported knowledge of physical activity as a lifestyle behavior to reduce cancer risk, and an increased number of motivating factors for engaging in physical activity were significantly associated with higher cancer screening intention (P < 0.001). With the addition of TPB constructs (i.e., subjective norms and perceived behavioral control), the final analytic model accounted for 31% of the variance in intention to screen for cancer. Findings suggest that the TPB could be used to tailor or design asset-based, cancer education interventions to effectively promote age-eligible cancer screenings among physically active adults. Educational content to increase social support for cancer screening and enhance perceived behavioral control to complete screening is essential in this population.


Assuntos
Intenção , Neoplasias , Pessoa de Meia-Idade , Adulto , Humanos , Feminino , Detecção Precoce de Câncer , Estudos Transversais , Inquéritos e Questionários , Neoplasias/diagnóstico , Neoplasias/prevenção & controle
2.
J Phys Chem A ; 126(17): 2619-2631, 2022 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-35467353

RESUMO

New approaches for the sensitive and accurate quantification of aerosol optical properties are needed to improve the current understanding of the unique physical chemistry of airborne particles and to explore their roles in fields as diverse as chemical manufacturing, healthcare, and atmospheric science. We have pioneered the use of cavity ring-down spectroscopy (CRDS), with concurrent angularly resolved elastic light scattering measurements, to interrogate the optical properties of single aerosol particles levitated in optical and electrodynamic traps. This approach enables the robust quantification of optical properties such as extinction cross sections for individual particles of known size. Our measurements can now distinguish the scattering and absorption contributions to the overall light extinction, from which the real and imaginary components of the complex refractive indices can be retrieved and linked to chemical composition. In this Feature Article, we show that this innovative measurement platform enables accurate and precise optical measurements for spherical and nonspherical particles, whether nonabsorbing or absorbing at the CRDS probe wavelength. We discuss the current limitations of our approach and the key challenges in physical and atmospheric chemistry that can now be addressed by CRDS measurements for single aerosol particles levitated in controlled environments.

3.
Gut ; 69(1): 103-111, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31023832

RESUMO

OBJECTIVE: We assessed the effect of surgical resection of colorectal cancer (CRC) on perioperative plasma vitamin D (25OHD) and C-reactive protein (CRP) level. We investigated the relationship between circulating vitamin D level and CRC survival. DESIGN: We sequentially sampled 92 patients undergoing CRC resection, and measured plasma 25OHD and CRP. For survival analyses, we assayed 25OHD and CRP in two temporally distinct CRC patient cohorts (n=2006, n=2100) and investigated the association between survival outcome, circulating vitamin D and systemic inflammatory response. RESULTS: Serial sampling revealed a postoperative fall (mean 17.3 nmol/L; p=3.6e-9) in plasma 25OHD (nadir days 1-2). CRP peaked 3-5 days postoperatively (143.1 mg/L; p=1.4e-12), yet the postoperative fall in 25OHD was independent of CRP. In cohort analyses, 25OHD was lower in the 12 months following operation (mean=48.8 nmol/L) than preoperatively (54.8 nmol/L; p=1.2e-5) recovering after 24 months (52.2 nmol/L; p=0.002). Survival analysis in American Joint Committee on Cancer stages I-III demonstrated associations between 25OHD tertile and CRC mortality (HR=0.69; 95% CI 0.46 to 0.91) and all-cause mortality (HR=0.68; 95% CI 0.50 to 0.85), and was independent of CRP. We observed interaction effects between plasma 25OHD and rs11568820 genotype (functional VDR polymorphism) with a strong protective effect of higher 25OHD only in patients with GG genotype (HR=0.51; 95% CI 0.21 to 0.81). We developed an online tool for predicted survival (https://apps.igmm.ed.ac.uk/mortalityCalculator/) that incorporates 25OHD with clinically useful predictive performance (area under the curve 0.77). CONCLUSIONS: CRC surgery induces a fall in circulating 25OHD. Plasma 25OHD level is a prognostic biomarker with low 25OHD associated with poorer survival, particularly in those with rs11568820 GG genotype. A randomised trial of vitamin D supplementation after CRC surgery has compelling rationale.


Assuntos
Biomarcadores Tumorais/sangue , Neoplasias Colorretais/cirurgia , Vitamina D/análogos & derivados , Idoso , Proteína C-Reativa/metabolismo , Estudos de Casos e Controles , Neoplasias Colorretais/sangue , Neoplasias Colorretais/genética , Feminino , Seguimentos , Predisposição Genética para Doença , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Prognóstico , Receptores de Calcitriol/genética , Análise de Sobrevida , Síndrome de Resposta Inflamatória Sistêmica/sangue , Vitamina D/sangue
4.
Analyst ; 140(11): 3676-86, 2015 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-25646176

RESUMO

In vivo measurements of neurotransmitters and related compounds have provided a better understanding of the chemical interactions that are a major part in functioning of brains. In addition, a great deal of technology has been developed to measure chemical species in other areas of living organisms. A key part of this work has been sampling technologies as well as direct measurements in vivo. This is extremely important when sampling from the smallest animal systems. Yet, very small invertebrate systems are excellent models and often have better defined and more easily manipulated genetics. This review focuses on in vivo measurements, electrochemical methods, fluorescence techniques, and sampling and is further narrowed to work over approximately the last three years. Rapid developments of in vivo studies in these model systems should aid in finding solutions to biological and bioanalytical challenges related to human physiological functions and neurodegenerative diseases.


Assuntos
Técnicas de Química Analítica/métodos , Invertebrados , Animais , Eletroquímica , Humanos , Larva , Imagem Óptica
5.
Phys Chem Chem Phys ; 17(14): 9465-70, 2015 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-25764990

RESUMO

Time-resolved infra-red (IR) absorption spectroscopy is used to follow the production of HF from the reaction of fluorine atoms in liquid acetonitrile (CH3CN). Photolysis of dissolved XeF2 using ∼50 fs duration, 267 nm laser pulses generates F atoms and XeF on prompt (sub-ps) timescales, as verified by broadband transient electronic absorption spectroscopy. The fundamental vibrational band of HF in solution spans more than 400 cm(-1) around the band centre at 3300 cm(-1), and analysis of portions of the time-resolved spectra reveals time constants for the rise in HF absorption that become longer to lower wavenumber. The time constants for growth of 40 cm(-1) wide portions of the IR spectra centred at 3420, 3320 and 3240 cm(-1) are, respectively, 3.04 ± 0.26, 5.48 ± 0.24 and 7.47 ± 0.74 ps (1 SD uncertainties). The shift to lower wavenumber with time that causes these changes to the time constants is attributed to evolution of the micro-solvation environment of HF following the chemical reaction. The initial growth of the high-wavenumber portion of the band may contain a contribution from relaxation of initially vibrationally excited HF, for which a time constant of 2.4 ± 0.2 ps is deduced from IR pump and probe spectroscopy of a dilute HF solution in acetonitrile.

6.
J Phys Chem A ; 119(22): 5701-13, 2015 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-25989469

RESUMO

We present measurements of the evolving extinction cross sections of individual aerosol particles (spanning 700-2500 nm in radius) during the evaporation of volatile components or hygroscopic growth using a combination of a single particle trap formed from a Bessel light beam and cavity ring-down spectroscopy. For single component organic aerosol droplets of 1,2,6-hexanetriol, polyethylene glycol 400, and glycerol, the slow evaporation of the organic component (over time scales of 1000 to 10,000 s) leads to a time-varying size and extinction cross section that can be used to estimate the refractive index of the droplet. Measurements on binary aqueous-inorganic aerosol droplets containing one of the inorganic solutes ammonium bisulfate, ammonium sulfate, sodium nitrate, or sodium chloride (over time scales of 1000 to 15,000 s) under conditions of changing relative humidity show that extinction cross-section measurements are consistent with expectations from accepted models for the variation in droplet refractive index with hygroscopic growth. In addition, we use these systems to establish an experimental protocol for future single particle extinction measurements. The advantages of mapping out the evolving light extinction cross-section of an individual particle over extended time frames accompanied by hygroscopic cycling or component evaporation are discussed.

7.
Pract Radiat Oncol ; 14(3): e205-e213, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38237893

RESUMO

PURPOSE: Significant heterogeneity exists in clinical quality assurance (QA) practices within radiation oncology departments, with most chart rounds lacking prospective peer-reviewed contour evaluation. This has the potential to significantly affect patient outcomes, particularly for head and neck cancers (HNC) given the large variance in target volume delineation. With this understanding, we incorporated a prospective systematic peer contour-review process into our workflow for all patients with HNC. This study aims to assess the effectiveness of implementing prospective peer review into practice for our National Cancer Institute Designated Cancer Center and to report factors associated with contour modifications. METHODS AND MATERIALS: Starting in November 2020, our department adopted a systematic QA process with real-time metrics, in which contours for all patients with HNC treated with radiation therapy were prospectively peer reviewed and graded. Contours were graded with green (unnecessary), yellow (minor), or red (major) colors based on the degree of peer-recommended modifications. Contours from November 2020 through September 2021 were included for analysis. RESULTS: Three hundred sixty contours were included. Contour grades were made up of 89.7% green, 8.9% yellow, and 1.4% red grades. Physicians with >12 months of clinical experience were less likely to have contour changes requested than those with <12 months (8.3% vs 40.9%; P < .001). Contour grades were significantly associated with physician case load, with physicians presenting more than the median number of 50 cases having significantly less modifications requested than those presenting <50 (6.7% vs 13.3%; P = .013). Physicians working with a resident or fellow were less likely to have contour changes requested than those without a trainee (5.2% vs 12.6%; P = .039). Frequency of major modification requests significantly decreased over time after adoption of prospective peer contour review, with no red grades occurring >6 months after adoption. CONCLUSIONS: This study highlights the importance of prospective peer contour-review implementation into systematic clinical QA processes for HNC. Physician experience proved to be the highest predictor of approved contours. A growth curve was demonstrated, with major modifications declining after prospective contour review implementation. Even within a high-volume academic practice with subspecialist attendings, >10% of patients had contour changes made as a direct result of prospective peer review.


Assuntos
Neoplasias de Cabeça e Pescoço , Garantia da Qualidade dos Cuidados de Saúde , Humanos , Neoplasias de Cabeça e Pescoço/radioterapia , Garantia da Qualidade dos Cuidados de Saúde/normas , Planejamento da Radioterapia Assistida por Computador/métodos , Planejamento da Radioterapia Assistida por Computador/normas , Estudos Prospectivos , Feminino , Radioterapia (Especialidade)/normas , Radioterapia (Especialidade)/métodos , Masculino
8.
Am J Surg ; 226(6): 762-767, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37453803

RESUMO

BACKGROUND: Sternal wound infections represent a source of significant morbidity and mortality following median sternotomy. The use of incisional negative pressure wound therapy in prevention has yet to be elucidated. METHODS: A retrospective study was conducted before and after a universal wound care protocol was implemented including the prophylactic use of negative pressure wound therapy (NPWT). The primary endpoint was sternal infections within 90 days of the index operation. RESULTS: In the control period, there was a 3.0% rate of sternal infection within 90 days compared to 0.8% in the intervention period (p < 0.001). An odds ratio of 0.25 (95% confidence interval 0.11, 0.57; p < 0.001) in the intervention period as compared to the control period was demonstrated. CONCLUSIONS: The use of a standardized wound care protocol including the universal application of NPWT for patients undergoing cardiac surgery with median sternotomy was an independent predictor of decreased rates of sternal infection.


Assuntos
Procedimentos Cirúrgicos Cardíacos , Tratamento de Ferimentos com Pressão Negativa , Humanos , Esternotomia/efeitos adversos , Infecção da Ferida Cirúrgica/etiologia , Estudos Retrospectivos , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Esterno/cirurgia , Resultado do Tratamento
9.
Front Nutr ; 10: 1106431, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37063332

RESUMO

Background: Vitamin D supplementation improves colorectal cancer (CRC) survival outcomes in randomized trials. The aim of this study was to test the feasibility, safety and efficacy of vitamin D supplementation in the pre- and perioperative period in patients undergoing CRC surgery. Methods: Patients were given 3200IU oral cholecalciferol (D3) per day perioperatively. Serial serum 25-hydroxyvitamin (25OHD) was measured by liquid chromatography tandem mass spectrometry and compared to untreated CRC controls. 25OHD and C-reactive protein (CRP) levels were compared using adjusted generalized linear mixed-effects models. Results: A total of 122 patients underwent serial perioperative sampling, including 41 patients given high-dose perioperative supplementation. Supplementation was well-tolerated with no adverse or serious adverse events related to supplementation reported. Pre-operative supplementation increased 25OHD levels on the day of surgery (103.9 vs. 42.5 nmol/l, P = 8.2E-12). Supplementation increased 25OHD levels at all post-operative timepoints (P < 0.001) and attenuated the post-operative drop in 25OHD (46 vs. 24% drop, P = 3.0E-4). Rate of vitamin D peri-operative insufficiency was significantly less in those on supplementation (e.g., day 3-5, 14 vs. 84%, P = 1.41E-08), with multivariate modeling across all timepoints indicating a ∼59 nmol/l higher 25OHD compared to control patients (P = 3.7E-21). Post-operative CRP was lower in patients taking supplementation (e.g., day 3-5 timepoint; 129 vs. 81 mg/l, P = 0.04). Conclusion: High dose pre-operative vitamin D supplementation is associated with higher perioperative 25OHD levels, lower rates of vitamin D insufficiency and reduced early post-operative CRP. Alongside published evidence for a beneficial effect of vitamin D on CRC survival outcomes, these novel findings provide strong rationale for early initiation of vitamin D supplementation after a diagnosis of CRC.

10.
Phys Chem Chem Phys ; 14(30): 10424-37, 2012 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-22499255

RESUMO

Transient, broadband infra-red absorption spectroscopy with picosecond time resolution has been used to study the dynamics of reactions of CN radicals with tetrahydrofuran (THF) and d(8)-THF in liquid solutions ranging from neat THF to 0.5 M THF in chlorinated solvents (CDCl(3) and CD(2)Cl(2)). HCN and DCN products were monitored via their v(1) (C≡N stretching) and v(3) (C-H(D) stretching) vibrational absorption bands. Transient spectral features indicate formation of vibrationally excited HCN and DCN, and the onsets of absorption via the fundamental bands of HCN and DCN show short (5-15 ps) delays consistent with vibrational relaxation within the nascent reaction products. This interpretation is confirmed by non-equilibrium molecular dynamics simulations employing a newly derived analytic potential energy surface for the reaction in explicit THF solvent. The rate coefficient for reactive formation of HCN (as determined from measurements on both the 1(1)(0) and 3(1)(0) fundamental bands) decreases with increasing dilution of the THF in CDCl(3) or CD(2)Cl(2), showing pseudo-first order kinetic behaviour for THF concentrations in the range 0.5-4.5 M, and a bimolecular rate coefficient of (1.57 ± 0.12) × 10(10) M(-1) s(-1) is derived. Simultaneous analysis of time-dependent HCN 1(1)(0) and 3(1)(0) band intensities following reaction of CN with THF (3.0 M) in CD(2)Cl(2) suggests that C-H stretching mode excitation is favoured, and this deduction is supported by the computer simulations. The results extend our recent demonstration of nascent vibrational excitation of the products of bimolecular reactions in liquid solution to a different, and more strongly interacting class of organic solvents. They serve to reinforce the finding that dynamics (and thus the topology of the reactive potential energy surface) play an important role in determining the nascent product state distributions in condensed phase reactions.

11.
Prev Med Rep ; 30: 101978, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36157713

RESUMO

To achieve the lowest risk level for various cancers, individuals would engage in several healthy lifestyle behaviors and age-eligible cancer screenings as recommended. Nonetheless, research has largely omitted exploration of concurrent primary and secondary prevention behaviors. This study was designed to explore influences of cervical cancer screening among physically active women who reported participation in recreational sports. U.S. based women between the ages of 21-49, who had never been diagnosed with cancer, were eligible to complete a web-based survey. Logistic regression analyses were conducted using SAS 9.4. On average, women were 31 years of age (N = 394) and self-identified as Black (51.3 %). Although low overall (30.7 %), higher odds of cervical cancer screening were associated with age (OR = 1.06, 95 % CI = 1.03-1.10), employment (OR = 2.43, 95 % CI = 1.14-5.18), knowledge of cancer-related risk behaviors (OR = 4.04, 95 % CI = 1.33-12.28), routine doctor's visit (OR = 4.25, 95 % CI = 1.56-11.54), and team-based vs individual-based sport participation (OR = 1.95, 95 % CI = 1.13-3.34). Our study provides insight into the health profile of physically active women, ages 21-49, as it relates to risks for cervical cancer. Screening uptake among this diverse sample was much lower than the general population and national goals set by Healthy People 2030. Interventions should be tailored to increase knowledge of cancer-related risk behaviors, access to healthcare, and recommended cervical cancer screenings among even assumed-to-be healthy populations.

12.
Phys Chem Chem Phys ; 13(23): 11438-45, 2011 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-21566843

RESUMO

We present an on-the-fly classical trajectory study of the Cl + CH(4)→ HCl + CH(3) reaction using a specific reaction parameter (SRP) AM1 Hamiltonian that was previously optimized for the Cl + ethane reaction [S. J. Greaves et al., J. Phys Chem A, 2008, 112, 9387]. The SRP-AM1 Hamiltonian is shown to be a good model for the potential energy surface of the title reaction. Calculated differential cross sections, obtained from trajectories propagated with the SRP-AM1 Hamiltonian compare favourably with experimental results for this system. Analysis of the vibrational modes of the methyl radical shows different scattering distributions for ground and vibrationally excited products.

13.
J Am Coll Health ; 69(2): 185-189, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-31513465

RESUMO

Objective: We sought to identify factors that influence Human Papillomavirus (HPV) vaccination rates in individuals at two higher education institutions in South Carolina (SC).Participants: We surveyed 1007 students with a mean age and standard deviation of 20.3 ± 3.3 from September 2018 to December 2018.Methods: Participants answered 13 questions, assessing HPV vaccination rates, demographics, and rationales for vaccination vs. non-vaccination.Results: Of 1007 respondents, 700 received HPV vaccination, 165 were unvaccinated, 75 received partial vaccination and 138 were uncertain. Commonalities in HPV vaccination existed between females (p = 0.037), individuals who received standard childhood vaccinations (p = 0.04), and those not native-born in SC (p < 0.001). Of non-vaccinated individuals, 37% "never thought about vaccination," 32% did not perceive a need for vaccination, and 31% reported vaccine safety as reasons for not receiving the vaccine.Conclusions: Promotion of HPV vaccination may benefit from targeting SC natives, males, and individuals who are under-vaccinated or unvaccinated.


Assuntos
Infecções por Papillomavirus , Vacinas contra Papillomavirus , Estudantes de Medicina , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Masculino , Infecções por Papillomavirus/prevenção & controle , South Carolina , Inquéritos e Questionários , Universidades , Vacinação
14.
Opt Express ; 18(13): 14238-44, 2010 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-20588558

RESUMO

We present evidence that aerosol droplets, approximately 1-2microm in diameter, can be optically bound over a 4mm distance within a volume formed by the overlap of the central cores and rings of two counterpropagating Bessel beams. The sizes of the individual polydisperse aerosol particles can be estimated from the angular variation of the elastic light scattering. Scattered light from the two orthogonally polarized trapping beams and from a Gaussian probe beam of different wavelength can be used to provide independent estimations of size. The coalescence of two droplets was observed and characterized.


Assuntos
Aerossóis/química , Pinças Ópticas , Água/química , Lasers , Nebulizadores e Vaporizadores , Tamanho da Partícula , Espalhamento de Radiação
15.
Science ; 221(4606): 169-71, 1983 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-6857277

RESUMO

Microvoltammetric electrodes were used to monitor dopamine released in the caudate nucleus of the rat after electrical stimulation of the medial forebrain bundle. The time resolution of the technique is sufficient to determine in vivo concentration changes on a time scale of seconds. Direct evidence identifying the substance released as dopamine was obtained both voltammetrically and pharmacologically. Administration of alpha-methyl-p-tyrosine terminates the release of dopamine, although tissue stores of dopamine are still present. Thus there appears to be a compartment for dopamine storage that is not available for immediate release. This compartment appears to be mobilized by amfonelic acid, since administration of this agent after alpha-methyl-p-tyrosine returns the concentration of dopamine released by electrical stimulation to 75 percent of the original amount.


Assuntos
Núcleo Caudado/metabolismo , Dopamina/metabolismo , Anfetamina/farmacologia , Animais , Núcleo Caudado/efeitos dos fármacos , Masculino , Metiltirosinas/farmacologia , Microeletrodos , Ácido Nalidíxico/análogos & derivados , Naftiridinas/farmacologia , Ratos , Ratos Endogâmicos , alfa-Metiltirosina
16.
Science ; 247(4949 Pt 1): 1454-7, 1990 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-2321007

RESUMO

Cell cycle-regulated gene expression is essential for normal cell growth and development and loss of stringent growth control is associated with the acquisition of the transformed phenotype. The selective synthesis of histone proteins during the S phase of the cell cycle is required to render cells competent for the ordered packaging of replicating DNA into chromatin. Regulation of H4 histone gene transcription requires the proliferation-specific promoter binding factor HiNF-D. In normal diploid cells, HiNF-D binding activity is regulated during the cell cycle; nuclear protein extracts prepared from normal cells in S phase contain distinct and measurable HiNF-D binding activity, while this activity is barely detectable in G1 phase cells. In contrast, in tumor-derived or transformed cell lines, HiNF-D binding activity is constitutively elevated throughout the cell cycle and declines only with the onset of differentiation. The change from cell cycle-mediated to constitutive interaction of HiNF-D with the promoter of a cell growth-controlled gene is consistent with, and may be functionally related to, the loss of stringent cell growth regulation associated with neoplastic transformation.


Assuntos
Ciclo Celular/genética , Proteínas de Ligação a DNA/metabolismo , Histonas/genética , Proteínas Nucleares/metabolismo , Regiões Promotoras Genéticas , Animais , Sequência de Bases , Linhagem Celular Transformada , Células Cultivadas , DNA/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Dados de Sequência Molecular , RNA Mensageiro/análise , Ratos , Homologia de Sequência do Ácido Nucleico , Transcrição Gênica , Células Tumorais Cultivadas
18.
J Chem Phys ; 130(3): 034307, 2009 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-19173521

RESUMO

Atomic sulfur products from predissociation of the lowest rotational states of SH/SD A (2)Sigma(+) (v(')=0,1,2) are studied using velocity map imaging. The dissociation process, which is slow compared to rotation, is dominated by interference effects due to predissociation of states with low rotation quantum numbers prepared by photoexcitation using overlapping transitions of different parities. The measured product angular distributions can be modeled using the methods presented recently by Kim et al. [J. Chem. Phys. 125, 133316 (2006)]. The S((3)P(J)) (2+1) resonance enhanced multiphoton ionization scheme used in the detection step of the experiment is sensitive to the angular momentum polarization of the atomic fragments. S((3)P(J)), J=2,1,0, fine-structure yields, angular distributions, and atom polarization parameters are reported. Strong polarization of the S((3)P(2,1)) products was observed along with a weak sensitivity of the branching ratio to excess energy and a full insensitivity of the atomic product polarization to excess energy. None of the data fit the predictions of either adiabatic or diabatic photodissociation, emphasizing the need for a fully quantum treatment.

19.
Contemp Clin Trials ; 86: 105848, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31536809

RESUMO

HIV continues to disproportionately impact African American (AA) communities. Due to delayed HIV diagnosis, AAs tend to enter HIV treatment at advanced stages. There is great need for increased access to regular HIV testing and linkage to care services for AAs. AA faith institutions are highly influential and have potential to increase the reach of HIV testing in AA communities. However, well-controlled full-scale trials have not been conducted in the AA church context. We describe the rationale and design of a 2-arm cluster randomized trial to test a religiously-tailored HIV testing intervention (Taking It to the Pews [TIPS]) against a standard information arm on HIV testing rates among AA church members and community members they serve. Using a community-engaged approach, TIPS intervention components are delivered by trained church leaders via existing multilevel church outlets using religiously-tailored HIV Tool Kit materials and activities (e.g., sermons, responsive readings, video/print testimonials, HIV educational games, text messages) to encourage testing. Church-based HIV testing events and linkage to care services are conducted by health agency partners. Control churches receive standard, non-tailored HIV information via multilevel church outlets. Secondarily, HIV risk/protective behaviors and process measures on feasibility, fidelity, and dose/exposure are assessed. This novel study is the first to fully test an HIV testing intervention in AA churches - a setting with great reach and influence in AA communities. It could provide a faith-community engagement model for delivering scalable, wide-reaching HIV prevention interventions by supporting AA faith leaders with religiously-appropriate HIV toolkits and health agency partners.


Assuntos
Negro ou Afro-Americano , Organizações Religiosas/organização & administração , Infecções por HIV/diagnóstico , Promoção da Saúde/organização & administração , Programas de Rastreamento/organização & administração , Competência Cultural , Infecções por HIV/etnologia , Humanos , Projetos de Pesquisa
20.
Appl Surf Sci ; 255(4): 1190-1192, 2008 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-19430585

RESUMO

With the chemical imaging capability of ToF-SIMS, biological molecules are identified and localized in membranes without any chemical labels. We have developed a model membrane system made with supported Langmuir-Blodgett (LB) monolayers. This simplified model can be used with different combinations of molecules to form a membrane, and thus represents a bottom-up approach to study individual lipid-lipid or lipid-protein interactions. We have used ternary mixtures of sphingomyelin (SM), phosphatidylcholine (PC), and cholesterol (CH) in the model membrane to study the mechanism of domain formation and interactions between phospholipids and cholesterol. Domain structures are observed only when the acyl chain saturation is different for SM and PC in the mixture. The saturated lipid, whether it is SM or PC, is found to be localized with cholesterol, while the unsaturated one is excluded from the domain area. More complicated model membranes which involve a functional membrane protein glycophorin are also investigated and different membrane properties are observed compared to the systems without glycophorin.

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