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1.
Artículo en Inglés | MEDLINE | ID: mdl-37946094

RESUMEN

Ethnic minority women experience disparities in mammography screening utilisation and breast cancer outcomes. This systematic review and meta-analysis synthesised multidomain and multilevel factors that intersect to influence the utilisation of mammography among ethnic minorities. A literature search was conducted in five databases (PubMed, Ovid MEDLINE, EMBASE, CINAHL, and PsycINFO) from inception to May 2022. Guided by the National Institute on Minority Health and Health Disparity research framework, the retrieved data were synthesised using narrative summaries and meta-analyses. Among the 27 studies, most (n = 24) reported individual, interpersonal, and community factors in the health care system domain. In the sociocultural domain, interpersonal and societal (n = 8) factors, such as modesty and karma beliefs, were less frequently identified than individual (n = 20) factors in relation to acculturation. Only individual-level factors were reported for the biological and physical/built environment (e.g., rural residence) domains. In the behavioural domain, cancer screening behaviours had a high combined prediction ability (odds ratio = 18.23; I2 = 23%), whereas interpersonal (e.g., family obligations) and community (e.g., neighbourhood violence) factors discouraged mammography screening. Special focus should be given to ethnic minority women, especially those living in rural areas, those with considerable family obligations, and those who have suffered from violence and other life pressures, to increase their access to mammography services. Multidomain and multilevel efforts, culturally appropriate strategies, and equity-advancing policies such as geographic access and insurance coverage would help to mitigate the ethnic disparities in mammography screening.

2.
Phys Rev E Stat Nonlin Soft Matter Phys ; 75(6 Pt 1): 061606, 2007 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17677272

RESUMEN

Carpenter [Phys. Rev. E 61, 532 (2000)] succeeded in determining a single universal model, called the P1 model, that could describe the ellipsometric critical adsorption data from the liquid-vapor interface of four different critical binary liquid mixtures near their critical demixing temperatures. The P1 model also recently has been used to describe neutron reflectometry data from a critical liquid mixture/crystalline quartz interface. However, in another recent study, the P1 model failed to simultaneously describe x-ray reflectometry and ellipsometry data from the liquid-vapor surface of the critical mixture n -dodecane + tetrabromoethane (DT). In this paper, we resolve this discrepancy between x-ray and ellipsometric data for the DT system. At large length scales (far from the interface) the local concentration is described by the P1 model in order to correctly reproduce the temperature dependence of the ellipsometric data. Close to the interface, however, the molecular structure must be correctly accounted for in order to quantitatively explain the x-ray data. An important conclusion that arises from this study is that neutron or x-ray reflectometry is most sensitive to short-range interfacial structure, but may provide misleading information about long-range interfacial structure. Ellipsometry provides a more accurate measure of this long-range interfacial structure. Complex interfacial structures, possessing both short- and long-range structure, are therefore best studied using multiple techniques.

3.
Phys Rev E Stat Nonlin Soft Matter Phys ; 72(4 Pt 1): 041601, 2005 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-16383390

RESUMEN

In critical binary liquid mixtures the preferential adsorption that occurs at liquid-vapor or liquid-solid surfaces is expected to be described by a universal surface scaling function. In this paper, we show that aniline strongly adsorbs at an oxide-coated Si wafer surface from a critical mixture of aniline + cyclohexane where this solid-liquid adsorption can be described by the same universal function found at liquid-vapor surfaces. For a tetrabromoethane + n-dodecane critical mixture the n-dodecane adsorption on an alkylsilane coated Si wafer cannot be described by previously determined adsorption functions. We speculate that this discrepancy is caused by chemical heterogeneities at the alkylsilane surface due to differing surface distributions of -CH3 and -CH2- groups within the silane layer.

4.
Phys Rev E Stat Nonlin Soft Matter Phys ; 72(1 Pt 1): 011509, 2005 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-16089972

RESUMEN

We have used direct inversion of x-ray reflectivity data to extract the liquid-vapor interface composition profile and the related critical scaling function of a binary mixture of dodecane and tetrabromoethane. The mixture was in the one-phase region above its critical point. The results indicate the formation of a monolayer of the lower surface tension component followed by an abrupt change to a mixed composition which gradually relaxes to the bulk composition deep within the fluid.

5.
Phys Rev E Stat Nonlin Soft Matter Phys ; 63(4 Pt 1): 041605, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11308860

RESUMEN

We have studied the thickness of vapor adsorbed films of the critical binary liquid mixture acetic acid plus nonane adsorbed onto a silicon wafer substrate as a function of temperature near the critical temperature. This critical film possesses opposite boundary conditions (+-) at its two surfaces and, due to the dissociation of acetic acid, both the electrostatic force and the dispersion force affect the adsorbed film thickness. On approaching the critical temperature T(c), an increase in the film thickness L is observed, implying that the sign of the universal Casimir amplitude Delta(+-) is positive, consistent with theoretical predictions. However, we find quantitative discrepancies in the value of Delta(+-) and the form of the critical Casimir pressure scaling function vartheta(+-) compared with previous experimental results. We attribute these discrepancies to the complex nature of the critical system studied in this experiment.

6.
Phys Rev E Stat Nonlin Soft Matter Phys ; 63(1 Pt 1): 011507, 2001 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11304266

RESUMEN

We present experimental evidence that dipoles exhibit orientational order at the critical interface of mixtures of polar plus nonpolar liquids using the technique of ellipsometry. In this technique the ellipticity rho; at the critical interface for all nonpolar or weakly polar fluids or fluid mixtures diverges as t(beta-nu) where t=(Tc-T)/Tc is the reduced temperature relative to the critical temperature Tc and beta=0.328, nu=0.632 are critical exponents. For polar fluids, however, the dipole-image dipole interaction at the interface can cause long-range orientational order resulting in deviations from this power-law divergence. Theoretical results predict that the surface orientational order parameter alpha2(z) approximately m(*4)[d2v(z)/dz2], where m(*) is the reduced dipole moment and v(z) is the local composition at position z within the interface. We find quantitative agreement with these predictions for two different critical binary liquid mixtures composed of a highly polar plus nonpolar component.

7.
Phys Rev E Stat Nonlin Soft Matter Phys ; 63(3 Pt 1): 031601, 2001 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11308656

RESUMEN

The line tension values of n-octane and 1-octene on a hexadecyltrichlorosilane coated silicon wafer, are determined by contact angle measurements at temperatures near a first-order wetting transition T(w). It is shown experimentally that the line tension changes sign as the temperature increases toward T(w) in agreement with a number of theoretical predictions. A simple phenomenological model possessing a repulsive barrier at l(0)=5.1+/-0.2 nm and a scale factor of B=78+/-6 provides a quantitative description of the experiments.

8.
J Pediatr Adolesc Gynecol ; 26(3 Suppl): S26-32, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23683824

RESUMEN

OBJECTIVE: To examine the prevalence of and changes in self-harm and suicide attempts and to predict these behaviors in relation to family functioning and positive youth development. DESIGN: We used quantitative data based on a large sample of adolescent participants. Participants had joined this study in a previous year when they were in Grade 7 (Wave 1). The present study focused on Wave 2 data and the comparison with Wave 1 data. SETTING AND PARTICIPANTS: The participants consisted of 2,579 Grade 8 students from 28 secondary schools in Hong Kong. A multi-stage cluster random sampling was adopted. MAIN OUTCOME MEASURE: Self-harm behavior, suicide attempt, the Chinese Family Assessment Instrument, the Chinese Positive Youth Development Scale. RESULTS: Approximately 23.5% of Grade 8 students had engaged in self-harm behavior in the preceding 12 months. Girls showed more self-harm behavior compared with the boys. Nearly 4.0% of adolescents attempted suicide in the preceding 12 months. Perceived family functioning and positive youth development predicted self-harm and suicidal ideation. Among the 4 second-order positive youth development qualities, the construct "general positive youth development qualities" was the strongest predictor of self-harm and suicide attempts. Compared with the Wave 1 data, more suicidal symptoms were observed in Wave 2, although the prevalence of self-harm behavior was similar across time. CONCLUSIONS: The prevalence of self-harm behavior among Chinese adolescents was high, but the level of suicidal behavior was low. Perceived family functioning and positive youth development can be regarded as protective factors for adolescents against self-harm and suicidal behaviors. General positive youth development quality is most important among the 4 second-order positive youth development qualities.


Asunto(s)
Desarrollo del Adolescente , Conducta Autodestructiva/epidemiología , Estudiantes/estadística & datos numéricos , Ideación Suicida , Adolescente , Pueblo Asiatico , Familia , Femenino , Hong Kong/epidemiología , Humanos , Masculino , Prevalencia , Factores de Riesgo , Instituciones Académicas , Estudiantes/psicología , Encuestas y Cuestionarios
9.
J Chem Phys ; 126(20): 204704, 2007 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-17552786

RESUMEN

Carpenter et al. [Phys. Rev. E 59, 5655 (1999); 61, 532 (2000)] managed to explain ellipsometric critical adsorption data collected from the liquid-vapor interface of four different critical binary liquid mixtures near their demixing critical temperature using a single model. This was the first time a single universal function had been found which could quantitatively describe the surface critical behavior of many different mixtures. There have also been various attempts to investigate this surface critical behavior using neutron and x-ray reflectometries. Results have been mixed and have often been at variance with Carpenter et al. In this paper, the authors show that neutron reflectometry data collected from a crystalline quartz-critical mixture interface, specifically deuterated water plus 3-methylpyridine, can be quantitatively explained using the model of Carpenter et al. derived from ellipsometric data.

10.
Langmuir ; 22(4): 1715-21, 2006 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-16460096

RESUMEN

We use precision ellipsometry to evaluate the existence of nanometer thick vapor films at the surface between a liquid and a hydrophobic alkylsilane coated Si wafer. We find no evidence for such vapor films. All of our fluid-solid ellipsometry measurements can be explained using a double layer model consisting of an oxide plus silane layer between the fluid and bulk Si substrate. We have carefully checked our ellipsometer for residual phase shifts which might, under certain circumstances, cause a mis-interpretation of the experimental results. We find that the most reliable ellipsometric results for thin films (which are relatively immune to the presence of small residual phase shifts) are collected at the Brewster angle. The dielectric constant of the native oxide coating is also compared with similar measurements for two thick (approximately 100-300 nm) thermally grown oxide coatings on a Si wafer.

11.
J Chem Phys ; 123(20): 204720, 2005 Nov 22.
Artículo en Inglés | MEDLINE | ID: mdl-16351306

RESUMEN

In a binary liquid mixture, the component possessing the lowest surface tension preferentially adsorbs at the liquid-vapor surface. In the past this adsorption behavior has been extensively investigated for critical binary liquid mixtures near the mixture's critical temperature T(c). In this fluctuation-dominated regime the adsorption is described by a universal function of the dimensionless depth zxi where xi is the bulk correlation length. Fewer studies have quantitatively examined adsorption for off-critical mixtures because, in this case, one must carefully account for both the bulk and surface crossover from the fluctuation-dominated regime (close to T(c)) to the mean-field dominated regime (far from T(c)). In this paper we compare extensive liquid-vapor ellipsometric adsorption measurements for the mixture aniline+cyclohexane at a variety of critical and noncritical compositions with the crossover theory of Kiselev and co-workers [J. Chem. Phys. 112, 3370 (2000)].

12.
Phys Rev Lett ; 86(10): 2070-3, 2001 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-11289857

RESUMEN

We study critical adsorption in the small surface field (h(1)) limit using a homologous series of critical liquid mixtures. The experiment data, in the one-phase regime, is accurately described by a universal surface scaling function G+(z/xi(+),z/l(h)) at distance z from the interface with correlation length xi(+) and surface field length l(h) approximately absolute value of (h(1))(-nu/Delta(1)), where h(1) approximately Deltasigma, the surface energy difference between the two components.

13.
Artículo en Inglés | MEDLINE | ID: mdl-11969549

RESUMEN

We present an accurate determination of the one- and two-phase universal surface scaling function which describes critical adsorption at noncritical interfaces of critical binary liquid mixtures in the strong surface field limit. The 95% confidence levels for this function are also determined. This function quantitatively describes ellipsometric critical adsorption data for three upper critical and one lower critical binary liquid mixtures.

14.
Artículo en Inglés | MEDLINE | ID: mdl-11969657

RESUMEN

The liquid crystal (-)7S5 spreads as a two-terraced droplet on an oxide covered (100) Si wafer. The thickness of the upper and lower terraces are respectively approximately 200 and approximately 40 A. This is the simplest system for which the de Gennes and Cazabat (dGC) terraced spreading model [C. R. Acad. Sci. II 310, 1601 (1990)] is applicable. We find that soon after the upper terrace acquires a flat top a hole develops in the center of this terrace. The hole propagates down to the depth of the first terrace. In this contribution we demonstrate that the dGC model is unstable to the formation of a hole in the center of the upper terrace for a two-terraced droplet. Our extended dGC model, which includes a hole in the upper terrace, provides a reasonable description of the average spreading dynamics for this system. However, this model has difficulties quantitatively accounting for all of the features exhibited by the dynamics, perhaps because experimentally the inner and outer borders of the upper terrace become irregular with time. These irregularities in the borders have not been included within the model.

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