Mechanical Performance of 3D-Printed Biocompatible Polycarbonate for Biomechanical Applications.

Additive manufacturing has experienced remarkable growth in recent years due to the customisation, precision, and cost savings compared to conventional manufacturing techniques. In parallel, materials with great potential have been developed, such as PC-ISO polycarbonate, which has biocompatibility certifications for use in the biomedical industry. However, many of these synthetic materials are not capable of meeting the mechanical stresses to which the biological structure of the human body is naturally subjected.

A Comparative Analysis of Chemical, Thermal, and Mechanical Post-Process of Fused Filament Fabricated Polyetherimide Parts for Surface Quality Enhancement.

Additive manufacturing technologies are increasingly being used in production systems because they shorten product development time and production cost, but surface integrity remains a limitation to meet the standards set by conventional manufacturing. In this research article, two chemical, one thermal, and three mechanical finishing operations are proposed to post-process fused filament fabricated Ultem 9085 parts. Their effects on the parts' surface quality and dimensional accuracy (changes in their width, height, length, and mass) are examined through optical and electron scanning microscopy, and the advantages and disadvantages of each method are discussed.

Experimental, Computational, and Dimensional Analysis of the Mechanical Performance of Fused Filament Fabrication Parts.

Process parameters in Additive Manufacturing (AM) are key factors in the mechanical performance of 3D-printed parts. In order to study their effect, a three-zone model based on the printing pattern was developed. This modelization distinguished three different zones of the 3D-printed part, namely cover, contour, and inner; each zone was treated as a different material.

Employment conditions and health inequities: a case study of Brazil.

This paper was prepared for the Employment Conditions and Health Inequalities Knowledge Network (EMCONET), part of the WHO Commission on the Social Determinants of Health. We describe the Brazilian context of employment conditions, labor conditions and health, their characteristics and causal relationships. The social, political and economic factors that influence these relationships are also presented with an emphasis on social inequalities, and how they are reproduced within the labor market and thereby affect the health and wellbeing of workers.

Influence of electrospun fiber mesh size on hMSC oxygen metabolism in 3D collagen matrices: experimental and theoretical evidences.

The traditional paradigm of tissue engineering of regenerating in vitro tissue or organs, through the combination of an artificial matrix and a cellular population has progressively changed direction. The most recent concept is the realization of a fully functional biohybrid, where both, the artificial and the biotic phase, concur in the formation of the novel organic matter. In this direction, interest is growing in approaches taking advantage of the control at micro- and nano-scale of cell material interaction based on the realization of elementary tassels of cells and materials which constitute the beginning point for the expansion of 3D more complex structures.

Real-time recurrent neural state estimation.

A nonlinear discrete-time neural observer for discrete-time unknown nonlinear systems in presence of external disturbances and parameter uncertainties is presented. It is based on a discrete-time recurrent high-order neural network trained with an extended Kalman-filter based algorithm. This brief includes the stability proof based on the Lyapunov approach.

[Noise-induced hearing loss and high blood pressure among city bus drivers].

Objective: To estimate the prevalence of occupational noise-induced hearing loss and arterial hypertension among city bus drivers.

Methods: A cross-sectional study was carried out on a probability random sample of 108 city bus drivers taken out of a total of 1,529 estimated professionals in the city of Campinas, Brazil, in 1991. Drivers were interviewed using questionnaires on job history, shift work and vacation schedules and underwent clinical and laboratory examinations including measures of blood pressure, pure-tone audiometry, speech audiometry, and anthropometric data analysis after an informed consent was obtained.