Observación de capas de grafeno mediante contraste óptico y dispersión Raman

Resumen: En este trabajo hemos usado la técnica de contraste óptico como herramienta de identificación preliminar y sencilla de capas de grafeno, la cual es más simple en comparación con la propuesta de otros autores y es validada con espectroscopia Raman. Para ello obtenemos grafeno y pocas capas de grafeno por exfoliación mecánica de grafito Kish. Adquirimos imágenes digitales, a través de un microscopio óptico, de las diferentes muestras depositadas sobre un sustrato de silicio con una película de óxido de silicio de 306.2 nm. Con un programa de análisis de imágenes adquirimos la componente verde de los números RGB, tanto de la muestra como del sustrato; con ello, calculamos el contraste óptico y determinamos el número de capas de grafeno. Logramos determinar de una a cuatro capas de grafeno

Women’s preferences for contraceptive counseling in Mexico: Results from a focus group study

Resumen Antecedentes La consejería sobre anticoncepción centrada en la usuaria es fundamental para satisfacer la demanda de métodos anticonceptivos y proteger los derechos humanos. Sin embargo, a pesar de los esfuerzos enfocados a optimizar la consejería, se tiene poco conocimiento sobre lo que es importante de este proceso para las usuarias fuera de los Estados Unidos. En el presente estudio, se investigaron las preferencias que tienen las mujeres con respecto de la consejería de métodos anticonceptivos en México, con el fin de mejorar la calidad del servicio. Método Se realizó una investigación cualitativa aplicada, utilizando seis grupos focales con 43 mujeres de dos ciudades de México con distintos tamaños de población y contextos socioculturales (Cuidad de México y Tepeji del Río, Hidalgo) con el objetivo de conocer sus preferencias en la consejería sobre métodos anticonceptivos. Se utilizó un enfoque de marco de referencia para crear códigos y realizar el análisis cualitativo de las transcripciones de los grupos focales. Resultados Las participantes, en congruencia con el marco de calidad y derechos humanos en los servicios de planificación familiar, expresaron su preferencia por elementos como la privacidad, confidencialidad, decisión informada y trato respetuoso. Se abordó el concepto de “atención respetuosa” en planificación familiar para evitar el abuso sexual o acoso, lo cual concuerda con las definiciones de la atención respetuosa en la salud materna. En contraste con los enfoques que abordan la efectividad anticonceptiva como un principio rector de la consejería, las participantes estaban más interesadas en que la consejería se centrara en una asesoría personalizada de sus necesidades y preferencias. Muchas de ellas, particularmente aquellas con mayor edad y/o menor nivel de escolaridad, consideran muy importante saber la opinión del prestador de servicios de salud sobre cuál método anticonceptivo deben usar, basado en la asesoría personalizada. Las participantes destacaron la necesidad de recibir asesoría médica o realizarse exámenes físicos para informar las recomendaciones del prestador. Se identificó que este deseo se debe en gran medida a que entre las mujeres existen creencias respecto a los efectos o incidentes que pudieran surgir con el uso de algunos métodos anticonceptivos, particularmente en la expulsión del DIU, asumiendo que muchos de éstos se podrían prevenir con revisiones médicas más exhaustivas para determinar el método más adecuado para cada mujer. La confianza en el prestador de salud se construía de distintas formas, y fue percibida como un aspecto esencial para satisfacer las necesidades de las mujeres con respecto a los métodos anticonceptivos. Conclusiones Los hallazgos permiten visibilizar la subrepresentación de las expectativas de las usuarias con relación a sus preferencias durante la consejería. Se resaltan recomendaciones específicas para mejorar la prestación de servicios en México, para asegurar que las usuarias cuenten con privacidad, confidencialidad, decisión informada, trato respetuoso, y asesoría personalizada—incluyendo otorgar mayor información sobre las razones por las que ocurren las expulsiones de DIUs postparto—durante las consultas sobre la anticoncepción. Los hallazgos sugieren que las intervenciones de consejería deberían priorizar un enfoque en el que se construya una buena relación entre el prestador de servicios y la usuaria, donde se fomente la confianza, así como contribuir a desarrollar habilidades de las y los prestadores de servicios de salud para asesorar las necesidades de las usuarias con el fin de otorgar un apoyo individualizado en el proceso de toma de decisiones sobre la elección del método anticonceptivo sin la imposición de las opiniones personales del prestador. La confianza es particularmente importante durante una consejería en planificación familiar debido a los abusos cometidos históricamente contra la autonomía de mujeres, que aún pueden estar influyendo en las percepciones sobre los programas de anticoncepción. Los hallazgos también pueden usarse para mejorar la evaluación cuantitativa de las experiencias de las usuarias

Correlates of unprotected sex with male clients among female sex workers in 13 Mexican cities.

This study examined correlates of unprotected vaginal and anal sex (UVA) with male clients among female sex workers (FSWs). Baseline data were gathered from 1089 FSWs recruited from 13 cities across Mexico enrolled in an evidence-based sexual risk reduction intervention. We used generalised estimating equations (GEE) to predict total UVA while controlling for the nested structure of the data. Total UVA with clients in the past month was examined in relation to selected sociodemographic, substance-use, and micro- and macro-environmental factors. A greater number of UVA acts was associated with three micro-level environmental factors (i.e. never getting condoms for free, unaffordability of condoms, greater number of clients per month), and three macro-level environmental factors (i.e. lower health and higher education indices, greater population size of city). These findings suggest the development of social and structural approaches to HIV prevention for FSWs in Mexico, including modification of venue-based policies that pressure FSWs to maximise client volume, changes to the work environment that promote availability and affordability of condoms, and improved population health. Moreover, our findings call for the development of context-specific HIV interventions that take into account variations in the sexual risk behaviours and HIV risk environments of FSWs throughout Mexico

Implementing Evidence-Based HIV Prevention for Female Sex Workers in Mexico: Provider Assessments of Feasibility and Acceptability.

This study examined service provider perceptions of feasibility and acceptability of implementing evidence-based practices for preventing HIV/AIDS and STIs in female sex workers (FSWs) in Mexico. Semi-structured interviews were conducted with 124 directors, supervisors and counselors from 12 reproductive health clinics located throughout Mexico participating in a large randomized controlled trial to scale-up the use of a psychoeducational intervention designed to promote FSW condom use and enhance safer sex negotiation skills. Feasibility was based on assessment of personal, organizational and social costs, benefits, and capacity. Costs included anxiety over intervention competency, purchase of condoms and other supplies, expenses of laboratory tests for HIV/STIs, and stigma associated with FSWs. Benefits included increase in personal knowledge and experience, enhanced clinic reputation and service delivery capacity, and increased public health. Capacity was expressed in terms of provider skills to deliver the intervention and additional workload. Acceptability was expressed in terms of provider enthusiasm in delivering these services and FSWs willingness to receive the services. Service provider evaluations of feasibility and acceptability of implementing evidence-based prevention interventions are grounded in local contexts that define costs and benefits of and capacity for implementation and determine features of the intervention and its implementation that are acceptable

Implementing Evidence-Based HIV Prevention for Female Sex Workers in Mexico: Provider Assessments of Feasibility and Acceptability.

This study examined service provider perceptions of feasibility and acceptability of implementing evidence-based practices for preventing HIV/AIDS and STIs in female sex workers (FSWs) in Mexico. Semi-structured interviews were conducted with 124 directors, supervisors and counselors from 12 reproductive health clinics located throughout Mexico participating in a large randomized controlled trial to scale-up the use of a psychoeducational intervention designed to promote FSW condom use and enhance safer sex negotiation skills. Feasibility was based on assessment of personal, organizational and social costs, benefits, and capacity. Costs included anxiety over intervention competency, purchase of condoms and other supplies, expenses of laboratory tests for HIV/STIs, and stigma associated with FSWs. Benefits included increase in personal knowledge and experience, enhanced clinic reputation and service delivery capacity, and increased public health. Capacity was expressed in terms of provider skills to deliver the intervention and additional workload. Acceptability was expressed in terms of provider enthusiasm in delivering these services and FSWs willingness to receive the services. Service provider evaluations of feasibility and acceptability of implementing evidence-based prevention interventions are grounded in local contexts that define costs and benefits of and capacity for implementation and determine features of the intervention and its implementation that are acceptable

Fidelity Moderates the Association Between Negative Condom Attitudes and Outcome Behavior in an Evidence-Based Sexual Risk Reduction Intervention for Female Sex Workers.

BackgroundIntervention fidelity and participant-level variables, such as negative attitudes towards condoms, are important variables to consider in the successful implementation of evidence-based HIV prevention interventions. Mujer Segura is an intervention that has been shown to be efficacious at reducing condomless sex for female sex workers (FSWs) in Mexico [1].PurposeWe examined main effects of fidelity, negative condom attitudes, and their interaction on the effectiveness of the Mujer Segura intervention at reducing condomless sex at intervention follow-up.MethodsOf the FSWs recruited from 13 cities across Mexico, 528 participated in the Mujer Segura intervention. We measured negative condom attitudes at baseline (comprising of beliefs and outcome evaluations) and condomless sex with clients at baseline and 6-month follow-up. Fidelity was measured by a fidelity checklist completed by independent raters; the sum of potentially 43 total elements completed by the counselor constituted fidelity.ResultsComplete fidelity was found in only 15.1% (n = 73) of sessions. There was no significant main effect of intervention fidelity on condomless sex with clients at follow-up. There was a significant and positive main effect of negative condom attitudes and a significant two-way interaction. At lower levels of fidelity, negative condom attitudes predicted greater condomless sex acts, whereas at higher levels of fidelity, the effect of condom attitudes became weaker. The results also indicated that the interaction between negative condom attitudes and fidelity were driven primarily by negative condom beliefs, as opposed to negative condom outcome evaluations.ConclusionsEnsuring treatment fidelity in an HIV prevention intervention is particularly important when participants have negative attitudes towards condoms

Sustainability of Evidence-Based Practices for HIV Prevention among Female Sex Workers in Mexico.

This study examined service provider perceptions of requirements for successful sustainment of an efficacious intervention for preventing HIV/AIDS and STIs in female sex workers (FSWs) in Mexico.Semi-structured interviews were conducted with 77 leaders and counselors from 12 community-based reproductive health clinics located throughout Mexico participating in a large hybrid effectiveness-implementation randomized controlled trial to scale-up the use of Mujer Segura, a psychoeducational intervention designed to promote condom use and enhance safer sex negotiation skills among FSWs.Five sets of requirements for sustainment were identified: 1) characteristics of the provider, including competence in delivering the intervention, need for continued technical support and assistance from outside experts, and satisfaction with addressing the needs of this population; 2) characteristics of the clients (i.e., FSWs), including client need and demand for services and incentives for participation; 3) characteristics of the organization, including its mission, benefits, and operations; 4) characteristics of the outer setting, including financial support and relationship with the community-based organization's central offices, and transportation and security in areas where FSWs live and work; and 5) outcomes associated with the intervention itself, including a reduction of risk through education and increased outreach through referrals from FSWs who received the intervention.Although the requirements for successful sustainment of interventions like Mujer Segura are consistent with the factors identified in many models of implementation, the results illustrate the importance of local context in assigning priority to these model elements and suggest that the five categories are not discrete entities but interconnected