High-resolution scanning tunneling microscope and its adaptation for local thermopower measurements in 2D materials.

We present the design, fabrication and discuss the performance of a new combined high-resolution Scanning Tunneling and Thermopower Microscope (STM/SThEM). We also describe the development of the electronic control, the user interface, the vacuum system, and arrangements to reduce acoustical noise and vibrations. We demonstrate the microscope's performance with atomic-resolution topographic images of highly oriented pyrolytic graphite (HOPG) and local thermopower measurements in the semimetal Bi2Te3. Our system offers a tool to investigate the relationship between electronic structure and thermoelectric properties at the nanoscale.

Detection and Quantification of HspX Antigen in Sputum Samples Using Plasmonic Biosensing: Toward a Real Point-of-Care (POC) for Tuberculosis Diagnosis.

Advancements that occurred during the last years in the diagnosis of Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis infection, have prompted increased survival rates of patients. However, limitations related to the inefficiency of an early detection still remain; some techniques and laboratory methods do not have enough specificity and most instruments are expensive and require handling by trained staff. In order to contribute to a prompt and effective diagnosis of tuberculosis, we report the development of a portable, user-friendly, and low-cost biosensor device for its early detection. By using a label-free surface plasmon resonance (SPR) biosensor, we have established a direct immunoassay for the direct detection and quantification of the heat shock protein X (HspX) of Mtb, a well-established biomarker of this pathogen, directly in pretreated sputum samples. The method relies on highly specific monoclonal antibodies that are previously immobilized on the plasmonic sensor surface. This technology allows for the direct detection of the biomarker without amplification steps, showing a limit of detection (LOD) of 0.63 ng mL-1 and a limit of quantification (LOQ) of 2.12 ng mL-1. The direct analysis in pretreated sputum shows significant differences in the HspX concentration in patients with tuberculosis (with concentration levels in the order of 116-175 ng mL-1) compared with non-tuberculosis infected patients (values below the LOQ of the assay).

Diseño y Evaluación de un micro viscosímetro de bajo costo utilizando un resonador de cristal de cuarzo y Arduino / Designing and evaluating a low-cost micro-viscometer using a quartz crystal resonator (QCR) and an Arduino DUE microcontroller board / Desenho e Avaliação de um micro viscosímetro de baixo custo usando um ressonador de cristal de quartzo e Arduino

Resumen El objetivo principal de este artículo es proponer el diseño de un micro viscosímetro de bajo coste utilizando un resonador de cristal de cuarzo (QCR) y una tarjeta Arduino DUE. En el artículo se explican los pasos del diseño del sensor y también su evaluación con dos líquidos de diferentes características: diluciones de glicerol en agua (comportamiento Newtoniano) y diluciones de albúmina de huevo extraída de huevos frescos en agua (comportamiento No-Newtoniano). Este estudio está relacionado con el interés de desarrollar nuevas herramientas para el diagnóstico de enfermedades cardiovasculares y artríticas.

Abstract This article outlines a design for a low-cost micro-viscometer, using a quartz crystal resonator (QCR) and an Arduino DUE programmable microcontroller board. The article explains the steps involved in designing the sensor and also how it was evaluated regarding two liquids having different characteristics: dilute aqueous glycerol (Newtonian behaviour) and dilutions of egg-white extracted from fresh eggs in water (non-Newtonian behaviour). This study was related to interest in developing new tools for diagnosing cardiovascular and arthritic diseases.

Resumo O principal objetivo deste trabalho é propor o projeto de um micro viscosímetro de baixo custo usando um ressonador de cristal de quartzo (QCR) e um cartão Arduino DUE. O artigo explica as etapas do desenho do sensor e também sua avaliação com dois líquidos de diferentes características: diluições de glicerol em água (comportamento newtoniano) e diluições de albumina de ovo extraídas de ovos frescos em água (comportamento não newtoniano). Este estudo está relacionado ao interesse de desenvolver novas ferramentas para o diagnóstico de doenças cardiovasculares e artríticas.