A Novel Insight into Keratoconus: Mechanical Fatigue of the Cornea

An integrated model for keratectasia risk assessment has received much attention over many years. The objective of this article is to propose a more complete, conceptual model by which high risk individuals can be screened, even with no topographic irregularity or corneal thinning. In this model, corneal ectasia results from the fatigue effect of cyclic shear stress and tensile stress, caused by eye rubbing and fluctuating intraocular pressure (IOP), respectively, on corneal microstructures. The model clarifies the importance of the magnitude of shearing force applied by eye rubbing, the amplitude of IOP fluctuations, the frequency of eye rubbing and IOP fluctuations, the geometry of the cornea, the temperature of the cornea, and the effects of oxidative stress on the cornea in keratectasia development. Therefore, preoperative screening strategies based on these concepts can be designed to assess the risk of keratectasia at an early stage, and select the best candidates who can benefit from keratorefractive surgeries

A Novel Insight into Keratoconus: Mechanical Fatigue of the Cornea

An integrated model for keratectasia risk assessment has received much attention over many years. The objective of this article is to propose a more complete, conceptual model by which high risk individuals can be screened, even with no topographic irregularity or corneal thinning. In this model, corneal ectasia results from the fatigue effect of cyclic shear stress and tensile stress, caused by eye rubbing and fluctuating intraocular pressure (IOP), respectively, on corneal microstructures. The model clarifies the importance of the magnitude of shearing force applied by eye rubbing, the amplitude of IOP fluctuations, the frequency of eye rubbing and IOP fluctuations, the geometry of the cornea, the temperature of the cornea, and the effects of oxidative stress on the cornea in keratectasia development. Therefore, preoperative screening strategies based on these concepts can be designed to assess the risk of keratectasia at an early stage, and select the best candidates who can benefit from keratorefractive surgeries

Editorial

…………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

Stochastic performance measurement in two-stage network processes: A data envelopment analysis approach

summary:In classic data envelopment analysis models, two-stage network structures are studied in cases in which the input/output data set are deterministic. In many real applications, however, we face uncertainty. This paper proposes a two-stage network DEA model when the input/output data are stochastic. A stochastic two-stage network DEA model is formulated based on the chance-constrained programming. Linearization techniques and the assumption of single underlying factor of the data are used to construct the equivalent deterministic linear programming model. The relationship between the stochastic efficiency of each stage and stochastic centralized efficiency of the whole process, at different confidence levels, is discussed. To illustrate the real applicability of the proposed approach, a real case on 16 commercial banks in China is given

Implementing cultural policies in universities of medical sciences: a model with mediating role of spirituality

Introduction: The aim of this study was to present a model for the implementation of cultural policies in relation to organizational culture with an emphasis on the mediating role of spirituality and mental health in universities of medical sciences. Methods: The present study was descriptive-correlational research. The data collection method was a combination of library and field studies and the data collection instruments included a review of documents, interviews and a researcher-made Cultural Policy Questionnaire, Workplace Spirituality Questionnaire, and Organizational Culture Questionnaire. The statistical population included 21496 hospital staffs and managers of medical sciences hospitals. Since structural equation modeling approach was used in this study, finally 472 people were statistically analyzed. The samples were determined using a stratified sampling method. In the present study, SPSS-23 and AMOS-24 software was used to analyze the data. Results: The research results confirmed the proposed research model and indicated a significant relationship between cultural policies and spirituality in university hospitals. Given the positive path coefficient, this relationship is direct. Based on the coefficient of determination (R2), 44% of spirituality changes in the hospital are explained by cultural policies. In addition to having a direct effect, cultural policies indirectly affect organizational culture through workplace spirituality. The level of direct impact was equal to 0.129 and the level of indirect impact through workplace spirituality was equal to 0.204. Conclusion: A direct relationship was between cultural policies and organizational culture and an indirect relationship between spirituality in university hospitals and organizational culture

Comparando os efeitos do letrozol e os efeitos do tratamento de rotina da síndrome dos ovários policísticos na melhora dos sintomas de hiperandrogenismo

Polycystic ovary syndrome (PCOS) is one of the common forms of chronic anovulation associated with an increase in androgens. This disorder is associated with important morbidities during reproductive years. The objective of this research was to compare the effects of letrozole and routine treatment (oral Ethinylestradiol, cyproterone acetate and metformin) of polycystic ovary syndrome in improving symptoms of hyperandrogenism (hirsutism, acne).This is an applied-experimental study in which, 80 patients diagnosed with PCOS (polycystic ovary syndrome) were randomly divided into two groups. The first group was treated with 2.5 mg of Letrozole daily and the second group was treated with 500 mg of metformin once per day, 100 mg of cyproterone acetate once per day since 5-15 days of menstruation and oral Ethinylestradiol daily since 5 -25 days of menstrual cycles and they were followed-up regularly and periodically in the endocrinology clinic. After collecting data, they were analyzed using spss Software. No significant difference was found between two groups in the improvement of the hirsutism (p = 0.27). No significant difference was found between two groups in the improvement of acne (p = 0.54). In addition, the results of this study did not show any significant difference between the two groups in terms of acne and hirsutism improvement in the 6-month follow up.Based on the results of this study, two groups did not differ significantly. However, given the reduction in Ferriman-Gallwey score, letrozole can be a suitable drug for treating the symptoms of hyperandrogenism. Extensive studies are required in this regard to prove this assumption.El síndrome de ovario poliquístico (SOP) es una de las formas comunes de anovulación crónica asociada con un aumento de los andrógenos. Este trastorno se asocia con importantes morbilidades durante los años reproductivos. El objetivo de esta investigación fue comparar los efectos del letrozol y el tratamiento de rutina (etinilestradiol oral, acetato de ciproterona y metformina) del síndrome de ovario poliquístico para mejorar los síntomas de hiperandrogenismo (hirsutismo, acné).Este es un estudio experimental aplicado en el que 80 pacientes diagnosticados con SOP (síndrome de ovario poliquístico) se dividieron aleatoriamente en dos grupos. El primer grupo se trató con 2,5 mg de letrozol al día y el segundo grupo se trató con 500 mg de metformina una vez al día, 100 mg de acetato de ciproterona una vez al día desde los 5 a 15 días de menstruación y etinilestradiol oral diariamente de 5 a 25 días. de ciclos menstruales y fueron seguidos regularmente y periódicamente en la clínica de endocrinología. Después de recopilar los datos, se analizaron utilizando el software 21 de spss.No se encontraron diferencias significativas entre los dos grupos en la mejora del hirsutismo (p = 0,27). No se encontraron diferencias significativas entre los dos grupos en la mejora del acné (p = 0.54). Además, los resultados de este estudio no mostraron diferencias significativas entre los dos grupos en cuanto a la mejoría del acné y el hirsutismo en el seguimiento de 6 meses.Sobre la base de los resultados de este estudio, dos grupos no difirieron significativamente. Sin embargo, dada la reducción en la puntuación de Ferriman-Gallwey, el letrozol puede ser un fármaco adecuado para tratar los síntomas de hiperandrogenismo. Se requieren estudios extensos a este respecto para probar este supuesto.A síndrome do ovário policístico (SOP) é uma das formas mais comuns de anovulação crônica associada a um aumento de andrógenos. Este distúrbio está associado a importantes morbidades durante os anos reprodutivos. O objetivo desta pesquisa foi comparar os efeitos do tratamento com letrozol e rotina (Etinilestradiol oral, acetato de ciproterona e metformina) da síndrome dos ovários policísticos na melhora dos sintomas de hiperandrogenismo (hirsutismo, acne).Este é um estudo experimental-aplicado no qual 80 pacientes diagnosticados com SOP (síndrome do ovário policístico) foram divididos aleatoriamente em dois grupos. O primeiro grupo foi tratado com 2,5 mg de Letrozole diariamente e o segundo grupo foi tratado com 500 mg de metformina uma vez por dia, 100 mg de acetato de ciproterona uma vez por dia desde 5-15 dias da menstruação e Etinilestradiol oral diariamente desde 5 -25 dias de ciclos menstruais e eles foram acompanhados regularmente e periodicamente na clínica de endocrinologia. Depois de coletar os dados, eles foram analisados usando o spss 21Software.Nenhuma diferença significativa foi encontrada entre os dois grupos na melhora do hirsutismo (p = 0,27). Nenhuma diferença significativa foi encontrada entre os dois grupos na melhora da acne (p = 0,54). Além disso, os resultados deste estudo não mostraram diferença significativa entre os dois grupos em termos de melhora da acne e do hirsutismo no seguimento de 6 meses.Com base nos resultados deste estudo, dois grupos não diferiram significativamente. No entanto, dada a redução no escore de Ferriman-Gallwey, o letrozol pode ser um medicamento adequado para tratar os sintomas do hiperandrogenismo. Estudos extensos são necessários a esse respeito para provar essa suposição

Photogrammetric Facial Analysis of Rhinoplasty Applicants in Shiraz

Background: Nose shape plays an important role in individuals’ facial appearance and its morphology depends on ethnicity, gender, and environmental conditions. Identifying nasal problems and measuring landmarks can lead to making a perfect surgery plan through preoperative image analysis. Methods: In this study, a photogrammetric analysis was performed on 120 female rhinoplasty applicants, aged 18-30 in Shiraz, Iran. Recorded parameters are nasal height and width, nasolabial and nasofrontal angle. Nasal indices were calculated according to heights and widths of noses. Also, facial asymmetry and nose hump checked for every patient. Results: Measurements showed that the average nasal index was 67.15 ± 4.72. Thus, the nose of rhinoplasty applicants was the leptorrhine type. Furthermore, the average nasofrontal and nasolabial angles were 145.22° ± 9.93°and 94.47° ± 14.25°. Among all applicants, 35 percent have an asymmetric nose and 31 percent have a nose hump. Conclusion:  An accurate facial analysis of rhinoplasty applicants was performed in this study, and the resultant facial profiles can be used in nose surgery planning and in further ethnic research