Paper and Fiber-Based Bio-Diagnostic Platforms: Current Challenges and Future Needs

In this perspective article, some of the latest paper and fiber-based bio-analytical platforms are summarized, along with their fabrication strategies, the processing behind the product development, and the embedded systems in which paper or fiber materials were integrated. The article also reviews bio-recognition applications of paper/fiber-based devices, the detected analytes of interest, applied detection techniques, the related evaluation parameters, the type and duration of the assays, as well as the advantages and disadvantages of each technique. Moreover, some of the existing challenges of utilizing paper and/or fiber materials are discussed. These include control over the physical characteristics (porosity, permeability, wettability) and the chemical properties (surface functionality) of paper/fiber materials are discussed. Other aspects of the review focus on shelf life, the multi-functionality of the platforms, readout strategies, and other challenges that have to be addressed in order to obtain reliable detection outcomes. Keywords: paper-based bio-analytical devices; shelf life; equipment-free bio-recognition; flow rate; readout strategies; multi-functional platform

Production of pectinases by <i>A. niger</i>: Influence of fermentation conditions

Response surface methodology was used for optimization of polygalacturonase (PG) and pectinesterase (PE) production in submerged fermentation by A.niger. A Central Composite Experimental Design was applied, consisting of 22 experiments, including eight central points. Variables studied were: fermentation time (24 to 120 h), pH (3.5 to 6.5) and initial concentration of pectin (5 to 20 g/l). Maximum PE production was 220 U/l, after 74 h of culture, in a medium containing 20 g/l of pectin (pH 6.5). The optimal conditions for PG production were pH: 4.1, 20 g/l of pectin and 94 h of fermentation with a maximum value of 1032 U/l. Under these conditions, the PE production was low (15 U/l). A liquid extract with high PG activity and low PE activity could be suitable to be used in food processing in order to reduce the production of methanol.Facultad de Ciencias Exacta

Continuous and Localized Mn Implantation of ZnO

We present results derived from continuous and localized 35 keV (55)Mn(+) ion implantations into ZnO. Localized implantations were carried out by using self-ordered alumina membranes as masks leading to ordered arrays of implanted volumes on the substrate surfaces. Defects and vacancies in the small implantation volumes of ZnO were generated due to the implantation processes besides the creation of new phases. Rapid thermal annealing was applied in the case of continuous implantation. The samples were characterized by HRSEM, GIXRD, Raman spectroscopy and RBS/C. Magnetic characterization of the samples pointed out appreciable differences among the samples obtained by the different implantation methods. This fact was mainly attributed to the different volume/surface ratios present in the implanted zones as well as to the increase of Mn atom concentrations along the grain frontiers in the nanostructured surfaces. The samples also showed a ferromagnetic transition phase at temperature value higher than room temperature

Model predictive control with constant switching frequency using a discrete space vector modulation with virtual state vectors

Finite states model predictive control (FS-MPC) appears as a promising control technique to be applied to power converters in the industry. However, the FS-MPC presents some drawbacks as non constant switching frequency and high sampling frequency. This work proposes a FS-MPC with constant switching frequency and low sampling frequency applying a discrete space vector modulation (DSVM) technique. The real state vectors of the converter are used together with new virtual state vectors forming switching sequences each sampling period. The advantages and disadvantages of the proposed FS-MPC with the DSVM are analysed using a two-level three-phase inverter connected to the grid as setup to introduce the proposed technique. Simulation results are presented, showing that using the proposed technique the switching frequency is fixed and the sampling frequency can be lowered without reducing the quality of the converter behaviour

Production of pectinases by <i>A. niger</i>: Influence of fermentation conditions

Response surface methodology was used for optimization of polygalacturonase (PG) and pectinesterase (PE) production in submerged fermentation by A.niger. A Central Composite Experimental Design was applied, consisting of 22 experiments, including eight central points. Variables studied were: fermentation time (24 to 120 h), pH (3.5 to 6.5) and initial concentration of pectin (5 to 20 g/l). Maximum PE production was 220 U/l, after 74 h of culture, in a medium containing 20 g/l of pectin (pH 6.5). The optimal conditions for PG production were pH: 4.1, 20 g/l of pectin and 94 h of fermentation with a maximum value of 1032 U/l. Under these conditions, the PE production was low (15 U/l). A liquid extract with high PG activity and low PE activity could be suitable to be used in food processing in order to reduce the production of methanol.Facultad de Ciencias Exacta

Susceptibilidad de Bemisia tabaci Gen. y Bactericera cockerelli sulc EN Solanum lycopersicum a insecticidas, en Aguascalientes, México

Durante las últimas décadas Bemisia tabaci Gen y Bactericera cockerelli Sulc se han considerado como plaga primaria en  el  cultivo de Solanum lycopersicum, desafortunadamente los insecticidas constituyen el principal método de control de estas plagas y desgraciadamente han demostrado poseer una gran capacidad para desarrollar resistencia a los insecticidas que normalmente se utilizan para su control, a pesar de ello, el estado actual de la resistencia de estas especies en México está poco documentada. Es por ello que el objetivo de este estudio fue evaluar la resistencia de Bemisia Tabaci Gen y Bacterciera cockerrelli Sulc en Solanum lycopersicum a los siguientes ingredientes activos, Spirodiclofén (0.4, 0.5 y 0.6 L.ha-1), Abamectina (0.5, 0.7 y 1.0 L.ha-1), Dicofol (0.5, 0.7 y 1.0 L.ha-1), Clofentezine (0.4, 0.5 y 0.6 L.ha-1), Cipermetrina (0.3, 0.4 y 0.5 L.ha-1), Thiacloprid (0.2, 0.3 y 0.4L.ha-1) e Imidacloprid + Deltametrina (0.2, 0.3 y 0.4 L.ha-1) en el estado de Aguascalientes obteniéndose que Spirodiclofén (0.4, 0.5 y 0.6 L.ha-1), Abamectina (0.5, 0.7 y 1.0 L.ha-1), Dicofol (0.5, 0.7 y 1.0 L.ha-1), Thiacloprid (0.2, 0.3 y 0.4 L.ha-1) y Imidacloprid + Deltametrina (0.2, 0.3 y 0.4L.ha-1)  tienen  más  del  80%  de  eficacia  en  ninfas  y adultos  de  Bemisia  tabaci.  para  el  caso  de Bactericera  cockerelli, Spirodiclofén (0.4, 0.5  y 0.6  L.ha-1), Abamectina (0.5, 0.7  y 1.0  L.ha-1), Dicofol (0.5, 0.7 y 1.0 L.ha-1), Thiacloprid (0.2, 0.3 y 0.4 L.ha-1) e Imidacloprid + Deltametrina (0.2,0.3 y 0.4 L.ha-1) tienen más del 80% de eficacia en ninfas y adultos

Peripheral giant cells granuloma as a rare early manifestation of primary hyperparathyroidism

Primary hyperparathyroidism occurs due to parathyroid adenoma, which as initial presentation in most cases includes recurrent nephrolithiasis (10-25%). Giant cell tumors (GDD) also called osteoclastomas or brown tumors affect the second decade of life and are currently a rare manifestation of primary hyperthyroidism. The incidence of lesion appearance in the maxillary bones is 4.5%. We presented the case of a 36 year old female patient with history of hypertension, who developed an increase in volume in the right maxillary region of 4×3 cm, with incapability of complete occlusion of dental arch, solid dysphagia, biopsy was performed with peripheral giant cells granuloma as a result, PTH serum levels were requested, with result of 1175 pg/ml and serum calcium of 13.24 mg/dl. Parathyroid gammagram was performed with hyperfunctioning parathyroid tissue. Patient underwent a selective parathyroidectomy. She had an adequate postoperative evolution and was discharged without complications. The patient had adequate follow up by head and neck surgery in external consultation, serum calcium 7.66 mg/dl, decrease of volume in right maxillary region to 3×3 cm; pathology report with parathyroid adenoma. Surgical treatment of brown tumor is still pending by the maxillofacial surgery department

Caracterización preliminar de emisiones de gases de efecto invernadero (CH4 y CO2) procedentes de volcanes de fango del Golfo de Cádiz

Mud volcanism represents an important migration pathway for methane and other gases from deeper reservoirs to the surface; however most submarine sources remain poor quantified. During SUBVENT2 cruise, water column over several mud volcanoes were surveyed for gas seepage characterization. Water samples of ROV Niskin and Rosette-CTD Niskin bottles were recovered above the Bonjardim, El Cid, Las Negras, Mercator, Algacel, Mvseis, Madrid and Yuma mud volcanoes, and at three newly discovered, mud volcano like structures, to quantify overall gases release fluxes from seabed. CO2 and CH4 concentrations were measured by potentiometric titration and using a gas chromatograph, respectively, in order to understand the relationship between physicochemical and geological processes. Gases concentrations decreased from shallower to deeper mud volcanoes. Values varied widely within 50 to 200 nM for CH4 and between 400 to 1500 μatm for fCO2. Greenhouse gases variations were large influenced by water column depth, temperature, salinity and possibly by anaerobic oxidation of methane (AOM). Our observations suggest that the emission of methane and carbon dioxide from the mud volcanoes structures studied here may be relevant at the present as a part of the carbon global cycle.Versión del edito