Median Time Period Research Articles

Experimental introduction of CO 2 and H 2 O into Mg-cordierite

<h3>Abstract</h3> Alterations in gray matter (GM) and monoamine oxidase A (MAO-A) distribution across the brain have been found in various neuropsychiatric conditions. MAO-A catalyzes the oxidative degradation of various monoamines and is thus implicated in neuroplastic processes that influence GM density (GMD) and microstructure (GMM) of the brain. Sex-specific differences in these patterns are well documented, however studying the long-term effects of certain sex steroids on the brain are limited due to hormonal fluctuations under naturalistic conditions. Due to the exact monitoring of plasma hormone levels and sex steroid intake, transgender individuals undergoing gender-affirming hormone therapy represent a valuable cohort to investigate such changes of GM and concomitant MAO-A density. Here, we investigated the effects of long-term gender-affirming hormone therapy over a median time period of 4.5 months on GMD and GMM as well as MAO-A distribution volume. To this end, 20 cisgender women, 11 cisgender men, 20 transgender women and 10 transgender men were recruited. All participants underwent two MRI scans in a longitudinal design. PET scans using [¹¹C]harmine were performed before each MRI session in a subset of 35 individuals. Between baseline and follow-up imaging, transgender subjects underwent gender-affirming hormone therapy. GM changes determined by diffusion weighted imaging (DWI) metrics for GMM and voxel based morphometry (VBM) for GMD were estimated using repeated measures ANOVA. Regions showing significant changes of both GMM and GMD were used for the subsequent analysis of MAO-A density. These involved the fusiform gyrus, rolandic operculum, inferior occipital cortex, middle and anterior cingulum, bilateral insula, cerebellum and the lingual gyrus (post-hoc tests: p_{FWE+Bonferroni} &lt; 0.025). In terms of MAO-A distribution volume, no significant effects were found. The present results are indicative of a reliable influence of gender-affirming hormone therapy on GMD and GMM following an interregional pattern. Nevertheless, future studies with larger sample sizes are needed to further investigate the relationship between sex steroids, gray matter alterations and MAO-A density.

Protein synthesis and protein degradation through the cell cycle of human NHIK 3025 cells in vitro

The rates of protein synthesis and protein degradation through the cell cycle of human NHIK 3025 cells in balanced growth were studied in cells synchronized by mitotic selection. The rates of protein synthesis and protein degradation per cell were found to increase smoothly from the first measurements after selection (mitosis) and until the beginning of the next mitosis. By the end of the cell cycle, both the rate of protein synthesis per cell and the rate of protein degradation per cell had doubled their values relative to the extrapolated values at the beginning of the cell cycle. The increase in the rates of protein synthesis and protein degradation seemed to follow the increase in total protein content closely, i.e. the rates of protein synthesis and protein degradation given as percentage of total protein were constant throughout the cell cycle of NHIK 3025 cells in balanced growth. The rate of protein accumulation, either measured directly or calculated as the difference between the rates of protein synthesis and protein degradation, allowed for a doubling of the protein content during the median time period required to complete the cell cycle.

Changes in Occupation After Aortocoronary Vein-Bypass Operation

The effect of aortocoronary vein-bypass operation on changes in occupational status was investigated in a cohort of 893 men. The median period of time between the operation and follow-up evaluation of postoperative occupational status was 14 months. The patients were divided into two age groups, with 55 years as the dividing point. The results showed that 11% of the younger men and 26% of the older group who were employed before the operation retired following the operation. In addition, 30% of the patients changed their occupational status following the operation. When occupational changes also resulted in changes in physical demands, 49% of the patients took new jobs that were less demanding physically, while 40% took jobs that were more demanding. Close to 9% of the patients were retired prior to the operation; about one fifth of them came out of retirement following the operation.

The role of sampling in population censuses: Its effect on timeliness and accuracy

Resumen A pesar de que la mayoría de los paisee del mundo han, a la fecha, comprendido la importancia de tener censos periódicos de población y han tomado las disposiciones para realizarlos regularmente, por una variedad de razones muchos paises encuentran dificil producir los resultados de esos censos en un periodo razonable de tiempo. Por ejempolo de los 17 paises de Latinoamerica para los cuales hay datos disponibles de recientes censos de poblacion al comienzo del ano 1967, por lo menos una serie de resultados finales habian sido publicados en 12 casos. Para esos 12 el tiempo promedio requerido para las mas tempranas publicaciones fue superior a los tres años; para algunos de esos paises parece probable que el plazo haya sido de cinco años. Este artículo discute algunos aspectos de la necesidad de ahorrar tiempo en la publicación de los resultados, investiga los efectos de largos retrazos en nuestra comprensión de los cambios que estan ocurriendo. Describe métodos de acelerar la preparación de informes, y sugiere un proqranui para expandir el empleo de muestras en los censos de los paises en desarrollo. Dos métodos pueden ser desarrollados mediante el uso de muestras para acelerar el tratamiento de los resultados censales. El primer método consiete en usar pequeñas muestras para un programa de informes preliminares, los cuales son seguidos luegos por informes finales basadoe en el censo total. En el segundo metodo se abandona la noción de trabajar con el cien por ciento de los datos, con exepción de un mínimo de información y recoqer la mayor parte de las estadísticas por medio de muestras es la principal técnica usada. Un programa exitoso en la producción de informes preliminares por medio de muestras fue llevado a cabo para 13 de los 17 paises latinoamericanos mencionados. En esos paises la ganancia media en tiempo como resultado de ese programa fue de alrededor de dos años. Ademas en todos los casos examinados los datos preliminares fueron muy parecidos a los resultados finales. Algunos paises, generalmente los mas industrializados, han extendido el uso de muestreo a la recolección de datos básicos para ahorrar tiempo y reducir costos. En general esto puedo ser hecho con solo un efecto menor en la exactitud. De hecho, si algunos de los ahorros en tiempo y recursos que surgen del uso de muestras son utilizados para mejorar los procedimientos, para poner más énfasis en supervisión y control del trabajo de campo, la reliabilidad puede ser incluso mayor. Además nuestro análisis indica que si se usan datos censoles continuamente durante una década y que si el uso de muestras permite adelantar dos años la publicación, el efecto total del error de muestreo va a ser menor que el causado por el uso durante largo tiempo de estadísticas atrasadas. Nosotros sugerimos un programa para el planeamiento de censos con una considerable expansión del uso de muestras. Un sumario breve de los mayores requerimientos y consideraciones de este programa es incluido en esie artículo.