Self-Assembly and Formation of Chromonic Liquid Crystals from the Dyes Quinaldine Red Acetate and Pyronin Y.

The aqueous self-assembly behavior of the dyes Quinaldine red acetate and Pyronin Y in a wide range of concentrations is reported here for the first time. (1)H NMR spectroscopy, polarized-light optical microscopy, and small and wide X-ray scattering were used to get insight into molecular interactions, phase boundaries and aggregate structure. Quinaldine red acetate and Pyronin Y self-organize into unimolecular stacks driven by attractive aromatic interactions. At high concentrations, spatial correlation among the molecular stacks gives rise to nematic liquid crystals in both systems. Quinaldine red acetate additionally produces a rare chromonic O phase built of columnar aggregates with anisotropic cross-section ordered in a rectangular lattice. The O phase changes into a columnar lamellar structure as a result of a temperature-induced phase transition. Results open the possibility of finding chromonic liquid crystals in other commercially available dyes with a similar molecular structure. This would eventually expand the availability of these unique soft materials and thus introduce new applications for marketed dyes.

[Competence perception survey among residents of orthopedics and trauma in a hospital of Yucatán México]. / Encuesta de percepción de competencias en médicos residentes de Ortopedia y Traumatología en un hospital de Yucatán, México.

BACKGROUND: The competence model states that what is most important is to have the elements to solve problems since abstract training does not provide enough tools to solve them. Therefore, it uses key and auxiliary competences that are linked to values such as attitudes. This study was performed to explore these competences. MATERIAL AND METHODS: This is a cross sectional, observational and descriptive trial. An anonymous survey with profile data of Orthopedics and Trauma residents was given, it contained 14 questions for residents of different academic levels. RESULTS: 24 residents participated out of the 35 registered in the course. 100% agreed to answer the survey, 54% was in the second year, 29% in the first year and 17% in the fourth year. 75% expressed auxiliary competences, 13% did not respond, 8% developed key competences and 4% don't know. CONCLUSIONS: Three main factors that are a negative influence to improve the knowledge of orthopedics were expressed. The most relevant is that residents describe a bad attitude from attending physicians, lack of willingness to teach and, poor interpersonal relationships. Awareness should be raised among orthopedics specialists so they understand that having the knowledge and skills is not enough to approach health issues in a comprehensive manner for each patient and the development of better competences should be fostered, especially key competences.

Improving breast cancer control among Latinas: evaluation of a theory-based educational program.

The study evaluated a theory-based breast cancer control program specially developed for less acculturated Latinas. The authors used a quasi-experimental design with random assignment of Latinas into experimental (n = 51) or control (n = 37) groups that completed one pretest and two posttest surveys. The experimental group received the educational program, which was based on Bandura's self-efficacy theory and Freire's empowerment pedagogy. Outcome measures included knowledge, perceived self-efficacy, attitudes, breast self-examination (BSE) skills, and mammogram use. At posttest 1, controlling for pretest scores, the experimental group was significantly more likely than the control group to have more medically recognized knowledge (sum of square [SS] = 17.0, F = 6.58, p < .01), have less medically recognized knowledge (SS = 128.8, F = 39.24, p < .001), greater sense of perceived self-efficacy (SS = 316.5, F = 9.63, p < .01), and greater adeptness in the conduct of BSE (SS = 234.8, F = 153.33, p < .001). Cancer control programs designed for less acculturated women should use informal and interactive educational methods that incorporate skill-enhancing and empowering techniques.

From ethnography to intervention: developing a breast cancer control program for Latinas.

Latinas are less likely than Anglo women to have appropriate breast cancer screening for reasons that may include culturally based beliefs as well as socioeconomic factors. This study employed ethnographic methods to explore breast cancer-related knowledge, attitudes, and behaviors among Latinas, Anglo women, and physicians, tested the generalizability of the findings in a telephone survey of randomly selected women, and used the results to design a culturally sensitive breast cancer control intervention in Orange County, Calif. Respondents for the ethnographic interviews included 28 Salvadoran immigrants, 39 Mexican immigrants, 27 Chicanas (U.S.-born Latinas of Mexican heritage), 27 Anglo women, and 30 physicians selected through organization-based network sampling. Latinas had very different beliefs about risk factors for breast cancer and held more fatalistic attitudes about the disease. For example, they believed that trauma to the breast was among the most important risk factors. Results of a telephone survey of 1225 randomly selected women (269 U.S.-born Latinas, 425 Mexican immigrants, 109 other Latina immigrants, and 422 Anglo women) generally confirmed the dissimilar beliefs among Latinas and Anglo women. The findings influenced our decision to design and pilot-test a breast cancer control intervention based on Bandura's self-efficacy theory and Freire's empowerment pedagogy. The methodology and findings of this study have important implications for future cancer control research and interventions.

[A problem-posing educational methodology for the prevention of HIV / AIDS]. / Una pedagogia de concientizacion para la prevencion del VIH / SIDA.

PIP: The problem-posing methodology of Brazilian educator Paulo Freire, using the reading circle approach previously deployed in successful literacy campaigns in developing countries, is introduced for application in AIDS information programs. The basis of this educational process is the dialogue where those to be educated resolve their problems by evaluating information critically, capturing concepts by codification and decodification, and transmitting information by creating relevant educational materials. Health circles are organized with women as educators to impart knowledge about AIDS and HIV: definitions, epidemiological components (sex, age, and risk behavior), means of transmission, stages of the progression of AIDS, prevention of HIV infection, and tests for detecting HIV antibodies. The dialogue explores knowledge and feelings about AIDS and how it affects life in the community reveals personal experiences and accounts of knowing someone who was HIV-positive, and develops action plans to minimize AIDS cases in the community. The Latin population of California, mainly of Mexican origin, with low levels of education, income, and acculturation and a high incidence of AIDS, is an appropriate target of such intervention. In 1980, there were 12.3 million people of Hispanic origin in the US. In August 1990, there were 143,280 persons diagnoses with AIDS according to the Centers for Disease Control. 78,878 of these (55%) were Anglos, and 21,752 (15%) were Hispanics. Among the Anglos, the incidence was 300/million inhabitants, while among Hispanics, it was 1059/million, a 3-field higher rate.^ieng

Sex, drugs and HIV: an ethnographic approach.

This is an ethnographic study of the sexual relationship that exists between a group of heroin addicted prostitutes and a Latino/Hispanic group of migrant undocumented workers from Mexico in Orange County, California. Some of the sexual practices elicited and observed by the ethnographer have implications for the transmission and prevention of the HIV. Of particular interest is a form of sexual behavior which is known to the participants as 'becoming milk brothers'. In this sexual practice several men have sexual intercourse with a single woman in rapid succession, allowing the possibility of HIV transmission to take place from male to female, from female to male, and from male to male.