Surface functionalization of a chalcogenide IR photonic sensor by means of a polymer membrane for water pollution remediation.

Rapid, simultaneous detection of organic chemical pollutants in water is an important issue to solve for protecting human health. This study investigated the possibility of developing an in situ reusable optical sensor capable of selective measurements utilizing a chalcogenide transducer supplemented by a hydrophobic polymer membrane with detection based on evanescent waves in the mid-infrared spectrum. In order to optimise a polyisobutylene hydrophobic film deposited on a chalcogenide waveguide, a zinc selenide prism was utilized as a testbed for performing attenuated total reflection with Fourier-transform infrared spectroscopy. To comply with the levels mentioned in health guidelines, the target detection range in this study was kept rather low, with the concentration range extended from 50 ppb to 100 ppm to cover accidental pollution problems, while targeted hydrocarbons (benzene, toluene, and xylene) were still detected at a concentration of 100 ppb. Infrared measurements in the selected range showed a linear behaviour, with the exception of two constantly reproducible plateau phases around 25 and 80 ppm, which were observable for two polymer film thicknesses of 5 and 10 µm. The polymer was also found to be reusable by regenerating it with water between individual measurements by increasing the water temperature and flow to facilitate reverse exchange kinetics. Given the good conformability of the hydrophobic polymer when coated on chalcogenide photonic circuits and its demonstrated ability to detect organic pollutants in water and to be regenerated afterwards, a microfluidic channel utilising water flow over an evanescent wave optical transducer based on a chalcogenide waveguide and a polyisobutylene (PIB) hydrophobic layer deposited on its surface was successfully fabricated from polydimethylsiloxane by filling a mold prepared via CAD and 3D printing techniques.

Toward Chalcogenide Platform Infrared Sensor Dedicated to the In Situ Detection of Aromatic Hydrocarbons in Natural Waters via an Attenuated Total Reflection Spectroscopy Study.

The objective of this study is to demonstrate the successful functionalization of the surface of a chalcogenide infrared waveguide with the ultimate goal of developing an infrared micro-sensor device. First, a polyisobutylene coating was selected by testing its physico-chemical compatibility with a Ge-Sb-Se selenide surface. To simulate the chalcogenide platform infrared sensor, the detection of benzene, toluene, and ortho-, meta- and para-xylenes was efficaciously performed using a polyisobutylene layer spin-coated on 1 and 2.5 µm co-sputtered selenide films of Ge28Sb12Se60 composition deposited on a zinc selenide prism used for attenuated total reflection spectroscopy. The thickness of the polymer coating was optimized by attenuated total reflection spectroscopy to achieve the highest possible attenuation of water absorption while maintaining the diffusion rate of the pollutant through the polymer film compatible with the targeted in situ analysis. Then, natural water, i.e., groundwater, wastewater, and seawater, was sampled for detection measurement by means of attenuated total reflection spectroscopy. This study is a valuable contribution concerning the functionalization by a hydrophobic polymer compatible with a chalcogenide optical sensor designed to operate in the mid-infrared spectral range to detect in situ organic molecules in natural water.

Were protective procedures against SARS-CoV-2 effective in an orthopaedic and trauma centre during the lockdown period? A retrospective study.

PURPOSE: The SARS-CoV-2 epidemic started in December 2019 in Wuhan. The lockdown was declared on March 16, 2020 in France. Our centre had to adapt daily practices to continue to take care of bone and soft tissue tumours and emergencies. Through this study, we wanted to assess the various procedures implemented during the lockdown period between March 17 and May 10. METHODS: A monocentric retrospective cohort study was conducted in Cochin Hospital (Paris, France). Patients included were those who had surgery during the lockdown period. To take care of COVID-19 positive and negative patients, various procedures have been set up: reverse transcriptase polymerase chain reaction (RT-PCR) tests for all hospitalized patients, a specific unit for COVID-positive patients, a specific surgical room, and use of protective personal equipment. To allow the effectiveness of the procedures implemented, we evaluated the number of complications attributed to SARS-CoV-2 and the number of patients who became COVID positive during hospitalization. RESULTS: During the lockdown period, there were 199 procedures of three types of procedures in our centre: 79 traumatology procedures (39.7%), 76 of bone and soft tissues tumours (38.2%), and 44 procedures related to infection (22.1%). We observed 13 complications (6.5%) during hospitalization, and only one patient became COVID-19 positive during the hospitalization. CONCLUSION: The COVID-19 epidemic has been a challenge for organization and adaptation to manage all COVID-19 positive and COVID negative. Through this study, we wanted to assess our procedures taken. They had been effective due to the low number of contamination and complications.

Surface Functionalization with Polymer Membrane or SEIRA Interface to Improve the Sensitivity of Chalcogenide-Based Infrared Sensors Dedicated to the Detection of Organic Molecules.

Priority substances likely to pollute water can be characterized by mid-infrared spectroscopy based on their specific absorption spectral signature. In this work, the detection of volatile aromatic molecules in the aqueous phase by evanescent-wave spectroscopy has been optimized to improve the detection efficiency of future in situ optical sensors based on chalcogenide waveguides. To this end, a hydrophobic polymer was deposited on the surface of a zinc selenide prism using drop and spin-coating methods. To ensure that the water absorption bands will be properly attenuated for the selenide waveguides, two polymers were selected and compared: polyisobutylene and ethylene/propylene copolymer coating. The system was tested with benzene, toluene, and ortho-, meta-, and para-xylenes at concentrations ranging from 10 ppb to 40 ppm, and the measured detection limit was determined to be equal to 250 ppb under these analytical conditions using ATR-FTIR. The polyisobutylene membrane is promising for pollutant detection in real waters due to the reproducibility of its deposition on selenide materials, the ease of regeneration, the short response time, and the low ppb detection limit, which could be achieved with the infrared photonic microsensor based on chalcogenide materials. To improve the sensitivity of future infrared microsensors, the use of metallic nanostructures on the surface of chalcogenide waveguides appears to be a relevant way, thanks to the plasmon resonance phenomena. Thus, in addition to preliminary surface-enhanced infrared absorption tests using these materials and a functionalization via a self-assembled monolayer of 4-nitrothiophenol, heterostructures combining gold nanoparticles/chalcogenide waveguides have been successfully fabricated with the aim of proposing a SEIRA microsensor device.

Modified zeolite-supported biofilm in service of pesticide biodegradation.

The development of biofilms on modified natural zeolites was investigated with purpose to obtain biocomposites with biodegradation activity towards pesticides MCPA (2-methyl-4-chlorophenoxyacetic acid) and glyphosate (N-(phosphonomethyl)glycine) for potential application in bioaugmentation of polluted agricultural soils. Microbial communities were selected from agricultural pesticide-contaminated soil/water samples and enriched on the basis of their ability to biodegrade the pesticides. In order to enhance affinity of microbial communities to the support material, the natural mineral zeolite was modified by nontoxic environmentally friendly cations (Li+, Na+, K+, NH4+, H+, Mg2+, Ca2+, Fe3+) by methods preserving its structure and characterised using powder XRD, surface area measurement and chemical composition analysis. Kinetics of pesticide degradation by the biocomposites was studied in liquid media. Results showed that according to zeolite modifications, the microbial activity and biodiversity changed. The best biodegradation rate of MCPA and glyphosate reached 0.12-0.13 mg/h with half-life of 16-18 h, which is considerably quicker than observed in natural environment. However, in some cases, biodegradation activity towards pesticides was lost which was connected to unfavourable zeolite modification and accumulation of toxic metabolites. High-throughput sequencing on the 16S rRNA genes of the biofilm communities highlighted the selection of bacteria genera known to metabolise MCPA (Aminobacter, Cupriavidus, Novosphingobium, Pseudomonas, Rhodococcus, Sphingobium and Sphingopyxis) and glyphosate (Pseudomonas). Altogether, results suggested that zeolites do not only have a passive role of biofilm support but also have protective and nutrient-supportive functions that consequently increase biodiversity of the pesticide degraders growing in the biofilm and influence the pesticide biodegradation rate.

Histopathological analysis of pre-implantation donor kidney biopsies: association with graft survival and function in one year post-transplantation.

INTRODUCTION: Pre-implantation kidney biopsy is a decision-making tool when considering the use of grafts from deceased donors with expanded criteria, implanting one or two kidneys and comparing this to post-transplantation biopsies. The role of histopathological alterations in kidney compartments as a prognostic factor in graft survival and function has had conflicting results. OBJECTIVE: This study evaluated the prevalence of chronic alterations in pre-implant biopsies of kidney grafts and the association of findings with graft function and survival in one year post-transplant. METHODS: 110 biopsies were analyzed between 2006 and 2009 at Santa Casa de Porto Alegre, including live donors, ideal deceased donors and those with expanded criteria. The score was computed according to criteria suggested by Remuzzi. The glomerular filtration rate (GFR) was calculated using the abbreviated MDRD formula. RESULTS: No statistical difference was found in the survival of donors stratified according to Remuzzi criteria. The GFR was significantly associated with the total scores in the groups with mild and moderate alterations, and in the kidney compartments alone, by univariate analysis. The multivariate model found an association with the presence of arteriosclerosis, glomerulosclerosis, acute rejection and delayed graft function. CONCLUSION: Pre-transplant chronic kidney alterations did not influence the post-transplantation one-year graft survival, but arteriosclerosis and glomerulosclerosis is predictive of a worse GFR. Delayed graft function and acute rejection are independent prognostic factors.

Histopathological analysis of pre-implantation donor kidney biopsies: association with graft survival and function in one year post-transplantation / Análise histopatológica de biópsias pré-implante de rim de doadores: associação com a sobrevida e função do enxerto um ano após o transplante

Introduction: Pre-implantation kidney biopsy is a decision-making tool when considering the use of grafts from deceased donors with expanded criteria, implanting one or two kidneys and comparing this to post-transplantation biopsies. The role of histopathological alterations in kidney compartments as a prognostic factor in graft survival and function has had conflicting results. Objective: This study evaluated the prevalence of chronic alterations in pre-implant biopsies of kidney grafts and the association of findings with graft function and survival in one year post-transplant. Methods: 110 biopsies were analyzed between 2006 and 2009 at Santa Casa de Porto Alegre, including live donors, ideal deceased donors and those with expanded criteria. The score was computed according to criteria suggested by Remuzzi. The glomerular filtration rate (GFR) was calculated using the abbreviated MDRD formula. Results: No statistical difference was found in the survival of donors stratified according to Remuzzi criteria. The GFR was significantly associated with the total scores in the groups with mild and moderate alterations, and in the kidney compartments alone, by univariate analysis. The multivariate model found an association with the presence of arteriosclerosis, glomerulosclerosis, acute rejection and delayed graft function. Conclusion: Pre-transplant chronic kidney alterations did not influence the post-transplantation one-year graft survival, but arteriosclerosis and glomerulosclerosis is predictive of a worse GFR. Delayed graft function and acute rejection are independent prognostic factors. .

Introdução: A biópsia renal pré-implante é uma ferramenta na decisão de utilização de enxertos de doadores falecidos com critérios expandidos, implantação de um ou dois rins e comparação com biópsias pós-transplante. O papel de alterações histopatológicas nos compartimentos renais tem mostrado resultados conflitantes como fator prognóstico na sobrevida e função do enxerto. Objetivo: Avaliar a prevalência de alterações crônicas nas biópsias pré-implante de enxertos renais e a associação dos achados com a função e sobrevida do enxerto em um ano pós-transplante. Métodos: Foram analisadas 110 biópsias entre 2006 e 2009 na Santa Casa de Porto Alegre, englobando doadores vivos, falecidos ideais e com critérios expandidos. A pontuação foi conforme critérios sugeridos por Remuzzi. A taxa de filtração glomerular (TFG) foi calculada pela fórmula MDRD resumida. Resultados: Não houve diferença estatística na sobrevida do enxerto de doadores estratificados conforme Remuzzi. A TFG apresentou associação significativa com os escores totais nos grupos com alterações leves e moderadas e nos compartimentos renais isoladamente, pela análise univariada. O modelo multivariado encontrou associação com a presença de arteriosclerose, glomeruloesclerose, rejeição aguda e retardo na função do enxerto. Conclusão: As alterações crônicas renais pré-transplante não tiveram influência na sobrevida do enxerto em um ano pós-transplante no nosso estudo. Arteriosclerose e glomeruloesclerose, em qualquer grau, são preditores de TGF pior no mesmo período. Retardo na função do enxerto e rejeição aguda são fatores ...