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Graphite sheet (GS) electrodes are flexible and versatile substrates for sensing electrochemical; however, their use has been limited to incorporate (bio)chemical modifiers. Herein, we demonstrated that a cold (low temperature) CO2 plasma treatment of GS electrodes provides a substantial improvement of the electrochemical activity of these electrodes due to the increased structural defects on the GS surface as revealed by Raman spectroscopy (ID/IG ratio), and scanning electron microscopy images. XPS analyses confirmed the formation of oxygenated functional groups at the GS surface after the plasma treatment that are intrinsically related to the substantial increase in the electron transfer coefficient (K0 values increased from 1.46 × 10-6 to 2.09 × 10-3 cm s-1) and with reduction of the resistance to charge transfer (from 129.8 to 0.251 kΩ). The improved electrochemical activity of CO2-GS electrodes was checked for the detection of emerging contaminant species, such as chloramphenicol (CHL), ciprofloxacin (CIP) and sulphanilamide (SUL) antibiotics, at around + 0.15, + 1.10 and + 0.85 V (versus Ag/AgCl), respectively, by square wave voltammetry. Limit of detection values in the submicromolar range were achieved for CHL (0.08 µmol L-1), CIP (0.01 µmol L-1) and SFL (0.11 µmol L-1), which enabled the sensor to be successfully applied to natural waters and urine samples (recovery values from 85 to 119%). The CO2-GS electrode is highly stable and inexpensive ($0.09 each sensor) and can be easily inserted in portable 3D printed cells for environmental on-site analyses.

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Background: The use of convalescent plasma (CP) has been considered for its immunological mechanisms that could benefit patients in moderate and severe stages of COVID-19. This study evaluated the safety and efficacy of the use of donor CP for COVID-19. Material and methods: A double-blind, randomized controlled clinical trial was conducted from May to October 2020. Thirty-nine participants with moderate (II) and severe (III) stages of COVID-19 confirmed by RT-PCR were included. The study randomization rate was set at 3:1. CPs were chosen for application with a neutralizing antibody titer of ≥1:32. Results: We observed a significantly lower 21-day post-transfusion mortality HR: 0.17 (95.0% CI [0.07−0.45, p < 0.001]) in the group receiving CP compared with the control group; protective units (PU) in the group receiving convalescent plasma after seven days were significantly higher (512 (32−16,384) vs. 96 (32−256), p = 0.01); the PAO2/FIO2 index showed a significant improvement in the group receiving CP (251.01 (109.4) vs. 109.2 (62.4), p < 0.001, in the control group). Conclusion: CP is safe and effective, as it decreased mortality in the CP group compared with the control group.

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The plasma jet transfer technique relies on a conductive wire at floating potential, which, upon entering in contact with a primary discharge, is capable of igniting a small plasma plume at the distal end of a long flexible plastic tube. In this work, two different long tube configurations were employed for the surface modification of polypropylene (PP) samples using argon as the working gas. One of the jet configurations has a thin copper (Cu) wire, which was installed inside the long tube. In the other configuration, the floating electrode is a metallic mesh placed between two plastic tubes in a coaxial arrangement. In the first case, the tip of the Cu wire is in direct contact with the working gas at the plasma outlet, whereas, in the second, the inner plastic tube provides an additional dielectric barrier that prevents the conductor from being in contact with the gas. Water contact angle (WCA) measurements on treated PP samples revealed that different surface modification radial profiles are formed when the distance (d) between the plasma outlet and target is changed. Moreover, it was found that the highest WCA reduction does not always occur at the point where the plasma impinges the surface of the material, especially when the d value is small. Through X-ray photoelectron spectroscopy (XPS) analysis, it was confirmed that the WCA values are directly linked to the oxygen-functional groups formed on the PP surfaces after the plasma treatment. An analysis of the WCA measurements along the surface, as well as their temporal evolution, together with the XPS data, suggest that, when the treatment is performed at small d values, the plasma jet removes some functional groups at the point where the plasma hits the surface, thus leading to peculiar WCA profiles.

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Abstract Introduction As the Coronavirus Disease 2019 (COVID-19) pandemic unfolds around the world; answers related to the antibody response against the virus are necessary to develop treatment and prophylactic strategies. We attempted to understand part of the immune response of convalescent plasma donation candidates. Method We carried out a cross-sectional, observational, non-intervention study, testing 102 convalescent plasma donation candidates for antibodies against the virus, relating these data to the time interval between symptom onset and sample collection, age, disease severity, and gender. Results In our sample, the individuals who developed a greater antibody response were the ones who had a longer time interval between symptom onset and sample collection, the ones who had been hospitalized and the subjects above 35 years old. Moreover, 17 individuals did not present any reactive antibodies. Conclusion These results are important in that they raise questions about the role of the humoral response against the virus, as some individuals do not develop antibodies to fight it. In addition, they help develop recruitment strategies for convalescent plasma donors, who should be asymptomatic for at least 21 days and are possibly more likely to have reactive antibodies after 35 days without symptoms.

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INTRODUCTION: As the Coronavirus Disease 2019 (COVID-19) pandemic unfolds around the world; answers related to the antibody response against the virus are necessary to develop treatment and prophylactic strategies. We attempted to understand part of the immune response of convalescent plasma donation candidates. METHOD: We carried out a cross-sectional, observational, non-intervention study, testing 102 convalescent plasma donation candidates for antibodies against the virus, relating these data to the time interval between symptom onset and sample collection, age, disease severity, and gender. RESULTS: In our sample, the individuals who developed a greater antibody response were the ones who had a longer time interval between symptom onset and sample collection, the ones who had been hospitalized and the subjects above 35 years old. Moreover, 17 individuals did not present any reactive antibodies. CONCLUSION: These results are important in that they raise questions about the role of the humoral response against the virus, as some individuals do not develop antibodies to fight it. In addition, they help develop recruitment strategies for convalescent plasma donors, who should be asymptomatic for at least 21 days and are possibly more likely to have reactive antibodies after 35 days without symptoms.

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Resumen La pandemia de COVID-19, presentó desde su inicio elevada mortalidad, sin tratamiento efectivo para pacientes graves. Basados en experiencia previa con plasma de convaleciente en fiebre hemorrágica Argentina, incorporamos a un estudio multicéntrico 90 pacientes con COVID-19 de los que 87 fueron evaluables. Colectamos 397 donaciones de plasma de 278 convalecientes. El plasma fue suministrado con una concentración de IgG de 0.7-0.8 (medidos por quimioluminiscencia Abbott) por cada 10 kg/ peso. La supervivencia a 28 días fue la variable de resultado primario. El 77% fueron varones, edad 54 ± 15.6 años (rango: 27-85); índice de masa corporal de 29.7 ± 4.4; tenían hipertensión 39%, diabetes 20.7%; 19.5% tenían alguna condición de inmunosupresión, y el 23% era personal de salud. Se administró plasma a 55 (63%) en respiración espontánea con oxígeno (con máscara reservorio en 80%), y a 32 (37%) en ventilación mecánica. La supervivencia global a 28 días fue del 80%; 91% en quienes recibían oxígeno suplementario y 63% en los que permanecían en ventilación mecánica (p = 0.0002). Hubo mejora significativa en la escala clínica de neumonía de la OMS a los 7 y a los 14 días. La ferritina, LDH y PaO /FiO, mejoraron en la semana post-infusión. Observamos un episodio de sobrecarga de volumen circulatorio y una reacción febril, leves. Las infusiones de plasma de convaleciente son factibles, seguras y potencialmente efectivas, especialmente antes de requerir ventilación mecánica. Constituyen una opción clínica atractiva para tratar formas graves de COVID-19 hasta que estén disponibles otras terapias eficaces.

Abstract The COVID-19 pandemic presented high mortality from its beginning, without effective treatment for seriously ill patients. Build on the experience in Argentine hemorrhagic fever with convalescent plasma, we incorporated 90 patients with COVID-19, of which 87 were evaluable, into a multicenter study. We collected 397 plasma donations from 278 convalescent donors. Patients received plasma with an IgG concentration of 0.7-0.8 (measured by Abbott chemiluminescence) for every 10 kg of body weight. Survival during the first 28 days was the primary objective; 77% were male, age 54 ± 15.6 y/o (range 27-85), body mass index 29.7 ± 4.4; hypertension 39% and diabetes 20.7%; 19.5% had an immunosuppressive condition, 23% were health workers. Plasma was administered to 55 (63%) on spontaneous breathing with oxygen supplementation (mainly oxygen mask with reservoir bag in 80%), and to 32 patients (37%) on mechanical ventilation. The 28-day survival rate was 80%; 91% in patients infused on spontaneous breathing and 63% in those on mechanical ventilation (p = 0.0002). There was a significant improvement in the WHO pneumonia clinical scale at 7 and 14 days, and in PaO / FiO , ferritin and LDH, in the week post-infusion. We observed an episode of circulatory volume overload and a febrile reaction, both mild. Convalescent plasma infusions are feasible, safe, and potentially effective, especially before requiring mechanical ventilation. They are an attractive clinical option for treating severe forms of COVID-19 until other effective therapies become available.

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Resumen Cada vez sabemos más sobre este enemigo mortal de la familia de los Betacoronavirus, llamado inicialmente 19-nCoV, causante de la COVID-19 (Coronavirus infectous disease por su sigla en inglés), hoy clasificado SARS-CoV-2, porque es responsable de producir el SARS (síndrome respiratorio agudo severo, por sus siglas en inglés) y que comparte una fuerte homología de secuencia con el SARS-CoV, su primo hermano causante de la epidemia en 2003 del SARS, ambos capaces de diseminarse rápidamente, en particular este, y causar un gran caos mundial como ha sucedido con esta pandemia. Con base en estudios previos de focalización en el SARS-CoV, y también en el virus causante del MERS (síndrome respiratorio del Oriente Medio, por sus siglas en inglés), y con el conocimiento que se tiene actualmente sobre el SARS-CoV-2, se exploran en este artículo algunas opciones terapéuticas para el manejo de la infección por este virus complejo y con capacidad letal, mencionando algunos aspectos de relevancia patogénica. Se enfatizó en las posibles alternativas de manejo desde la fisiopatología y patogénesis hasta la evidencia actualmente disponible. Exploraremos el uso probable de ECA2 recombinante, algunas moléculas experimentales, revisaremos los antimaláricos (cloroquina e hidroxicloroquina), esteroides, azitromicina, antivirales específicos como remdesivir, lopinavir/ritonavir, biológicos como tocilizumab, anticuerpos monoclonales antivirales, y haremos énfasis en la trasfusión de plasma de convalecientes desde el principio de inmunización pasiva, de gran utilidad.

Abstract We know more and more about this deadly enemy of the Betacoronavirus family, initially called 19- nCoV that causes COVID-19 (Coronavirus infectous disease), today classified SARS-CoV-2, because it is responsible for producing SARS (severe acute respiratory syndrome), It shares a strong sequence homology with SARS-CoV, its cousin that caused the 2003 SARS epidemic, both capable of spreading rapidly, particularly this one and causing great global chaos as has happened with this pandemic. Based on previous studies targeting SARS-CoV, and also on the virus that causes MERS (Middle East Respiratory Syndrome); and with the current knowledge about SARS-CoV-2, we will explore some therapeutic options for the management of infection by this complex and lethal virus, mentioning some aspects of pathogenic relevance. Possible management alternatives from the pathophysiology and pathogenesis to the evidence currently available were emphasized. We will explore the probable use of ECA2 recombinate, some experimental molecules, we will review some of the antimalarials (chloroquine and hydroxychloroquine), steroids, azithromycin, specific antivirals such as remdesivir, lopinavir / ritonavir, biologics such as tocilizumab, monoclonal antiviral antibodies, and we will emphasize transfusion of convalescent plasma from the passive immunization principle, very useful.

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La enfermedad del coronavirus 2019 (COVID-19) causada por la infección por el nuevo coronavirus (SARS-CoV-2) ha creado una pandemia que ha llevado a una lucha mundial para hacer frente al gran número de personas infectadas, muchas de las cuales requieren cuidados intensivos. Hasta la fecha, no existe un tratamiento antivirus específico para COVID-19. El uso de transfusiones de plasma de convalecientes podría ser de gran valor en la pandemia actual. Los pacientes con SRAS-CoV-2 recuperados recientemente que pueden ser donantes adecuados se someten a aféresis para obtener plasma de convalecencia que contenga anticuerpos con títulos elevados, siempre que cumplan los criterios de donación de sangre. En esta revisión, resumimos la literatura existente sobre el plasma convaleciente como una opción terapéutica para COVID-19. Es importante señalar que es necesario estudiar más a fondo el momento adecuado para la administración de plasma de convalecencia y la gravedad de sus efectos adversos. El plasma de convalecencia ofrece la posibilidad de convertirse en una opción de tratamiento prometedora inmediata al evaluar los medicamentos existentes y desarrollar nuevas vacunas y terapias específicas.

The coronavirus disease 2019 (COVID-19) caused by novel coronavirus (SARS-CoV-2) infection has created a pandemic leading to a global struggle to cope with the sheer numbers of infected persons, many of whom require intensive care support. To date, there is no specific antivirus treatment for COVID-19. The use of convalescent plasma transfusions could be of great value in the current pandemic. Recently recovered SARS-CoV-2 patients who may be suitable donors undergo apheresis in order to obtain convalescent plasma containing high-titer antibodies, granted they meet blood donation criteria. In this review, we summarize existing literature around convalescent plasma as a therapeutic option for COVID-19. It is important to note that the appropriate timing on convalescent plasma administration and the severity of its adverse effects needs to be further studied. Convalescent plasma provides the potential to render an immediate promising treatment option while evaluating existing drugs and developing new specific vaccines and therapies.

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The COVID-19 pandemic presented high mortality from its beginning, without effective treatment for seriously ill patients. Build on the experience in Argentine hemorrhagic fever with convalescent plasma, we incorporated 90 patients with COVID-19, of which 87 were evaluable, into a multicenter study. We collected 397 plasma donations from 278 convalescent donors. Patients received plasma with an IgG concentration of 0.7-0.8 (measured by Abbott chemiluminescence) for every 10 kg of body weight. Survival during the first 28 days was the primary objective; 77% were male, age 54 ± 15.6 y/o (range 27-85), body mass index 29.7 ± 4.4; hypertension 39% and diabetes 20.7%; 19.5% had an immunosuppressive condition, 23% were health workers. Plasma was administered to 55 (63%) on spontaneous breathing with oxygen supplementation (mainly oxygen mask with reservoir bag in 80%), and to 32 patients (37%) on mechanical ventilation. The 28-day survival rate was 80%; 91% in patients infused on spontaneous breathing and 63% in those on mechanical ventilation (p = 0.0002). There was a significant improvement in the WHO pneumonia clinical scale at 7 and 14 days, and in PaO2 / FiO2, ferritin and LDH, in the week post-infusion. We observed an episode of circulatory volume overload and a febrile reaction, both mild. Convalescent plasma infusions are feasible, safe, and potentially effective, especially before requiring mechanical ventilation. They are an attractive clinical option for treating severe forms of COVID-19 until other effective therapies become available.

La pandemia de COVID-19, presentó desde su inicio elevada mortalidad, sin tratamiento efectivo para pacientes graves. Basados en experiencia previa con plasma de convaleciente en fiebre hemorrágica Argentina, incorporamos a un estudio multicéntrico 90 pacientes con COVID-19 de los que 87 fueron evaluables. Colectamos 397 donaciones de plasma de 278 convalecientes. El plasma fue suministrado con una concentración de IgG de 0.7-0.8 (medidos por quimioluminiscencia Abbott) por cada 10 kg/ peso. La supervivencia a 28 días fue la variable de resultado primario. El 77% fueron varones, edad 54 ± 15.6 años (rango: 27-85); índice de masa corporal de 29.7 ± 4.4; tenían hipertensión 39%, diabetes 20.7%; 19.5% tenían alguna condición de inmunosupresión, y el 23% era personal de salud. Se administró plasma a 55 (63%) en respiración espontánea con oxígeno (con máscara reservorio en 80%), y a 32 (37%) en ventilación mecánica. La supervivencia global a 28 días fue del 80%; 91% en quienes recibían oxígeno suplementario y 63% en los que permanecían en ventilación mecánica (p = 0.0002). Hubo mejora significativa en la escala clínica de neumonía de la OMS a los 7 y a los 14 días. La ferritina, LDH y PaO2/FiO2, mejoraron en la semana post-infusión. Observamos un episodio de sobrecarga de volumen circulatorio y una reacción febril, leves. Las infusiones de plasma de convaleciente son factibles, seguras y potencialmente efectivas, especialmente antes de requerir ventilación mecánica. Constituyen una opción clínica atractiva para tratar formas graves de COVID-19 hasta que estén disponibles otras terapias eficaces.

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The present work aims to study the effect of the addition of poly (hydroxybutyrate) PHB as reinforcement in thermoplastic cornstarch (TPS) produced by the thermal compression molding method. Initially, the physical and chemical properties of TPS with different amounts of glycerol as the plasticizer (25, 30 and 35 wt%), are evaluated. Then, the composites, including 35% glycerol and different PHB contents (10, 20 and 30 wt%), are prepared. Additionally, the surface of the PHB granules is modified by plasma treatment using atmospheric air and sulfur hexafluoride (SF6) gas. In order to evaluate the influence of the PHB contents before and after the plasma treatment, the composites are characterized by FTIR, TGA, DSC, XRD, SEM, and mechanical tests. SEM showed a homogeneous distribution of PHB granules in the TPS matrix. On the other hand, the micrographs of the composites, using the high concentration of plasma-treated PHB, showed the agglomerated particles in the starch matrix, which represented stress concentrators, and showed weak interfacial adhesion leading to the poor mechanical properties. The thermogravimetric analysis of the composites with PHB treated by plasma showed a higher thermal stability compared to the composites of TPS and untreated PHB.

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Bacterial adhesion on three different surfaces: untreated Ti, plasma nitriding, and plasma carbonitriding Ti substrates were investigated. The samples were placed in bacterial cultures of Pseudomonas aeruginosa to assess biofilm formation. The correlation between the amount of bacteria attached to the surface after a lapse of time with nanotopography and physicochemical properties was performed. TiN showed the highest capacity to avoid bacterial adhesion, while presenting intermediate roughness and wettability. Although the surface of TiCN had the highest surface roughness and low contact angle (high wettability), bacterial adhesion was intermediate on this sample. Untreated Ti, even though presenting a smooth surface and low wettability, had the highest tendency to form biofilms.

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The high lignin to cellulose ratio of coir fibers results in low compatibility between these fibers and natural polymers like starch, leading to poor mechanical properties in the composites. Plasma treatment using either air or oxygen proved to be an effective in removing the lignin rich amorphous layer on coir fibers, as it was clearly observed by SEM. The ratio of the FTIR signal related to lignin (1508cm-1) and cellulose (1317cm-1) decreases 10 times for air plasma treated fibers and 20 times for oxygen plasma treated samples. Composites of plasma treated short coir fibers and thermoplastic starch presented considerable increase in mechanical properties in comparison to composites made with untreated fibers. Tensile strength increased by up to 300% and elastic modulus improved by a factor of nearly 20 times, which was associated with enhanced fiber-matrix adhesion after plasma treatment with oxygen for 7.2min at 80W power.

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The chemical inertness of carbon nanotubes (CNT) requires some degree of "defect engineering" for controlled deposition of metal oxides through atomic layer deposition (ALD). The type, quantity, and distribution of such defects rules the deposition rate and defines the growth behavior. In this work, we employed ALD to grow titanium oxide (TiO2) on vertically aligned carbon nanotubes (VACNT). The effects of nitrogen doping and oxygen plasma pretreatment of the CNT on the morphology and total amount of TiO2 were systematically studied using transmission electron microscopy, Raman spectroscopy, and thermogravimetric analysis. The induced chemical changes for each functionalization route were identified by X-ray photoelectron and Raman spectroscopies. The TiO2 mass fraction deposited with the same number of cycles for the pristine CNT, nitrogen-doped CNT, and plasma-treated CNT were 8, 47, and 80%, respectively. We demonstrate that TiO2 nucleation is dependent mainly on surface incorporation of heteroatoms and their distribution rather than structural defects that govern the growth behavior. Therefore, selecting the best way to functionalize CNT will allow us to tailor TiO2 distribution and hence fabricate complex heterostructures.

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Titanium is one of the most used materials in implants and changes in its surface can modify the cellular functional response to better implant fixation. An argon plasma treatment generates a surface with improved mechanical proprieties without modifying its chemical composition. Oxidative stress induced by biomaterials is considered one of the major causes of implant failure and studies in this field are fundamental to evaluate the biocompatibility of a new material. Therefore, in this work, induction of oxidative stress by titanium surfaces subjected to plasma treatment (PTTS) was evaluated. The viability of CHO-k1 cells was higher on PTTS discs. Cells grown on titanium surfaces are subjected to intracellular oxidative stress. Titanium discs subjected to the plasma treatment induced less oxidative stress than the untreated ones, which resulted in improved cellular survival. These were associated with improved cellular antioxidant response in Plasma Treated Titanium Surface (PTTS). Furthermore, a decrease in protein and DNA oxidative damage was observed on cells grown on the roughed surface when compared to the smooth one. In conclusion, our data suggest that the treatment of titanium with argon plasma may improve its biocompatible, thus improving its performance as implants or as a scaffold in tissue engineering.

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