Sample sizes of studies on diagnostic accuracy: literature survey

OBJECTIVES: To determine sample sizes in studies on diagnostic accuracy and the proportion of studies that report calculations of sample size. DESIGN: Literature survey. DATA SOURCES: All issues of eight leading journals published in 2002. METHODS: Sample sizes, number of subgroup analyses, and how often studies reported calculations of sample size were extracted. RESULTS: 43 of 8999 articles were non-screening studies on diagnostic accuracy. The median sample size was 118 (interquartile range 71-350) and the median prevalence of the target condition was 43% (27-61%). The median number of patients with the target condition--needed to calculate a test's sensitivity--was 49 (28-91). The median number of patients without the target condition--needed to determine a test's specificity--was 76 (27-209). Two of the 43 studies (5%) reported a priori calculations of sample size. Twenty articles (47%) reported results for patient subgroups. The number of subgroups ranged from two to 19 (median four). No studies reported that sample size was calculated on the basis of preplanned analyses of subgroups. CONCLUSION: Few studies on diagnostic accuracy report considerations of sample size. The number of participants in most studies on diagnostic accuracy is probably too small to analyse variability of measures of accuracy across patient subgroups.

Dendritic spikes in apical dendrites of neocortical layer 2/3 pyramidal neurons

Layer 2/3 (L2/3) pyramidal neurons are the most abundant cells of the neocortex. Despite their key position in the cortical microcircuit, synaptic integration in dendrites of L2/3 neurons is far less understood than in L5 pyramidal cell dendrites, mainly because of the difficulties in obtaining electrical recordings from thin dendrites. Here we directly measured passive and active properties of the apical dendrites of L2/3 neurons in rat brain slices using dual dendritic-somatic patch-clamp recordings and calcium imaging. Unlike L5 cells, L2/3 dendrites displayed little sag in response to long current pulses, which suggests a low density of I(h) in the dendrites and soma. This was also consistent with a slight increase in input resistance with distance from the soma. Brief current injections into the apical dendrite evoked relatively short (half-width 2-4 ms) dendritic spikes that were isolated from the soma for near-threshold currents at sites beyond the middle of the apical dendrite. Regenerative dendritic potentials and large concomitant calcium transients were also elicited by trains of somatic action potentials (APs) above a critical frequency (130 Hz), which was slightly higher than in L5 neurons. Initiation of dendritic spikes was facilitated by backpropagating somatic APs and could cause an additional AP at the soma. As in L5 neurons, we found that distal dendritic calcium transients are sensitive to a long-lasting block by GABAergic inhibition. We conclude that L2/3 pyramidal neurons can generate dendritic spikes, sharing with L5 pyramidal neurons fundamental properties of dendritic excitability and control by inhibition.

España sigue a la cola de la investigación europea

Entrevista a José María Pereda, en la que se reflexiona sobre la situación de los investigadores del CSIC.

Pii Gemitvs Catholicorvm : In quibuscunque Ecclesiae necessitatibus effundendi, Litanijs aliquot & precibus eo accommodatis /

Mode of access: Internet.

Thomae Sydenham ... Opera medica ... : tomus primus [-secundus] : cum elenchis rerum & indicibus necessariis.

"Guilhelmi Musgrave ... De arthritide symptomatica dissertatio ..." -- "Guilhelmi Musgrave ... De arthritide anomala, sive interna dissertatio ...", con pie de imprenta fechado en 1715.

Transactions of the American Society for Steel Treating.

Publication suspended Jan. - Oct. 1931.

Guía práctica para la realización de una Auditoría de Recursos Humanos en El Hospital Nacional “Dr. Jorge Arturo Mena” de Santiago De María Usulután

Este proyecto de Tesis se desarrolla en la Institución Hospital Nacional "Dr. Jorge Arturo Mena", municipio de Santiago de María, departamento de Usulután, el cual consta con doscientos diez empleados, dicha institución presta servicios de salud en atención ambulatoria, asimismo atención hospitalaria. Una auditoría de Recursos Humanos, es parte de una auditoría administrativa, la cual tiene como objetivo evaluar procesos, así como grado de cumplimiento de los objetivos establecidos por la institución. Una de las circunstancias que radica en la institución es el funcionamiento inadecuado del Recurso Humano y el Control del mismo, esto ocasiona que el empleado incumpla con Normas, Leyes y sus Reglamentos respectivos, así mismo, este incumplimiento pone en riesgo las condiciones laborales de los mismos. Para evaluar el Hospital se realizó una Guía Práctica para la realización de una Auditoría de Recursos Humanos en dicha institución para que sirva como base para el Hospital detectando así las posibles deficiencias, asimismo, sirve al ente fiscalizador de las Instituciones Públicas, la Corte de Cuentas de la República. Este proyecto va enfocado para las oficinas contables, como una guía para la realización de Auditoría de Recursos Humanos que sirva como base para la realización de la misma. Así mismo, va dirigida al sector docente y estudiantes de las diferentes universidades como material pedagógico en el desarrollo y práctica de la auditoría. El objetivo principal de este proyecto de Tesis es ser una herramienta para evaluar si se cumplieron con políticas y objetivos establecidos por la institución y además para la toma de decisiones con el fin de controlar, organizar y manejar el Recurso Humano eficientemente. Además, facilitará a que la administración cumpla con las obligaciones establecidas en normas, leyes y reglamentos.

Superman no existe y la superbacteria : la droga milagrosa 2

Fondo Margaritainés Restrepo

Catalytic Asymmetric Transfer Hydrogenation of Imines: Recent Advances

In this review article recent developments in the asymmetric transfer hydrogenation of imines from 2008 up to today are presented. The main methodology involves either metal-catalyzed procedures in the presence of a chiral ligand or organocatalyzed technologies using a Hantzsch ester and a chiral BINOL-derived phosphoric acid. The most important procedures are collected, paying special attention to the application of this methodology in synthetic organic chemistry.

Projeto de intervenção para controle dos fatores de risco modificáveis entre portadores de hipertensão em Pratinha/MG

Análise da situação de saúde da área de abrangência de uma equipe de Saúde da Família no município de Pratinha/MG, indicou a prevalência de fatores de risco modificáveis entre as pessoas portadoras de hipertensão cadastradas associada a dificuldade de manutenção do regime terapêutico adequado como o problema prioritário a ser enfrentado na rotina de trabalho. Objetiva-se apresentar proposta de intervenção para controle dos fatores de risco modificáveis entre portadores hipertensão e melhoria da adesão ao regime terapêutico em uma equipe de Saúde da Família de Pratinha/MG. O desenvolvimento da proposta pautou-se na construção coletiva do Planejamento Situacional e Estratégico em Saúde. Considera-se a implementação de Grupo Operativo como ação crucial para a melhoria assistencial e enfrentamento desta demanda. Em especial se a prática for conduzida por trabalho multidisciplinar, abordagens inovadoras e o compromisso da equipe de saúde em reavaliar o processo de desenvolvimento dos grupos, ajustando rumos