Elektroden aus Legierungen der Übergangsmetalle Vanadium, Titan und Niob und der reinen Metalle reagieren in Abhängigkeit von der Zusammensetzung und des mit ihnen im Kontakt stehenden wässrigen Elektrolyten in höchst unterschiedlicher Weise. Für eine systematische Untersuchung der elektrochemischen Eigenschaften der Elektroden wurden neben den reinen Metallen binäre und ternäre Legierungen aus Vanadium, Titan und Niob, die jeweils Vanadium enthalten, hergestellt. Es wurden zum ersten Mal zusammenhängend ihre physikalischen und chemischen Eigenschaften durch Strukturuntersuchungen und Untersuchungen der Zusammensetzung der Oberfläche sowie der Morphologie bestimmt. Von den, sich mit einer halbleitenden Oxidschicht überziehenden Metallen, wurden die Halbleitereigenschaften im Elektrolytkontakt studiert, die grundlegenden Korrosionseigenschaften sowie ihr elektrochemisches Verhalten als Elektrodenmaterial in potentiometrischen Zellen und durch Strom-Spannungsmessungen bestimmt. Zur Aufklärung der Kinetik der Oxidschichtbildung wurden potentiostatische Stromtransienten ermittelt und mit bekannten Modellen verglichen.

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SyfteAtt utvärdera effekterna och bieffekterna av tandblekningsprodukter innehållande eller utsöndrande av väteperoxid på permanenta tänder hos personer under 18 år. Studien gjordes med tanke på barn som drabbats av missfärgade tänder med ett objektivt och subjektivt behandlingsbehov. Detta i syfte att insamla all nuvarande forskning på området samt ställa detta mot EU-direktiven utfärdade 2012. SökstrategierEn systematisk sökning av litteraturen gjordes i databaserna Medline, Cochrane, Embase och Scopus. Inkluderade artiklar skulle vara på antingen Engelska, Svenska, Danska eller Norska. SelektionskriterierStudierna skulle vara gjorda på personer under 18 år med produkter som innehöll eller utsöndrande väteperoxid. Enbart studier på permanenta tänder inkluderades. Studierna var tvungna att utvärdera positiva och/eller negativa effekter av behandlingen. Blekningen skulle utföras in vivo. Fallrapporter inkluderades enbart i syfte att finna eventuella allvarliga bieffekter. ResultatTotalt identifierades 214 artiklar varav 13 stycken uppfyllde inkluderings- och exkluderings-kriterierna. Fyra studier bedömdes ha låg risk av bias, åtta av medelhög samt en som hög risk av bias. Syftet och studiedesignen varierade mellan de inkluderade studierna. De flesta studierna var utförda på mildare missfärgningar samtidigt som de saknade erforderliga uppföljningstider. SlutsatsDet finns inte tillräckligt med studier gjorda på personer under 18 år som utvärderar effekterna av bleking med väteperoxid på fall med mer omfattande missfärgningar. Ett begränsat antal studier med medelhög risk av bias ger ett visst stöd för blekning med väteperoxid på mildare fall av missfärgningar. Samtidigt rapporterades ett stort antal milda, övergående bieffekter. Tills motsatsen bevisats finns ett etiskt stöd för EU-direktiven etablerade 2012. / AimTo investigate the effects and adverse events of tooth whitening performed on children with permanent teeth by the use of products containing or releasing hydrogen peroxide. This was made considering children affected by objectively and subjectively observed tooth discolorations in purpose to consolidate existing research and compare it to the EU directives established 2012.Search strategiesA systematic search of the literature was conducted using the databases Medline, Cochrane, Embase and Scopus. Only studies published in English, Swedish, Danish and Norwegian were included. Selection criteriaThe selection criteria aimed to include studies performed on patients under the age of 18, using whitening products containing or releasing hydrogen peroxide. The bleaching process had to be performed in vivo on permanent teeth. Case reports were included only to be separately reviewed looking for severe side effects and adverse events.ResultsA total of 214 articles were identified and 13 met the inclusion criteria. Four papers were judged to have a low risk of bias, eight a moderate risk and one a high risk of bias. Most studies were performed on mild discolorations while they lacked in necessary follow-up times.ConclusionThere are not enough studies evaluating the effect of using hydrogen peroxide to bleach more severe discolorations on individuals under 18 years old. A limited number of studies showed some support for bleaching with hydrogen peroxide on mild tooth discolorations. Parallel to this, the included studies demonstrated a high number of mild and transient adverse events. Until proven otherwise, the lack of studies gives some ethical support to the EU-directives established 2012.

El objetivo de esta investigación fue comparar in vitro los cambios en la rugosidad superficial de la estructura dentaria, generados por los diferentes agentes blanqueadores que contienen peróxido de hidrógeno (HP). El estudio consideró 50 especímenes obtenidos de dientes de bovino, seccionados en bloques dentales (7mm x 7mm x 7mm) y preparados para realizar una lectura inicial de rugosidad superficial (Ra), utilizando un perfilómetro. Las muestras fueron divididas aleatoriamente en 5 grupos (n= 10) según el agente blanqueador al que fueron expuestos: grupo1: Whiteness HP Maxx al 35%, grupo 2: Opalescence Boost 40% de HP, grupo 3: Opalescence Go 10% de HP, el grupo 4: Whiteness Perfect al 10% de peróxido de carbamida (CP) como control positivo y, el grupo 5: control negativo, con suero fisiológico. Al finalizar la etapa del blanqueamiento, las muestras se mantuvieron en suero fisiológico; finalmente, fueron sometidas al perfilómetro para determinar los parámetros de rugosidad superficial post blanqueamiento. Para el análisis estadístico se utilizó el paquete estadístico SPSS® 27.0. Para identificar si los datos siguen una distribución normal, se utilizó la prueba Shapiro Wilk (p > 0.05), luego se aplicó la prueba no paramétrica Prueba de Wilcoxon para muestras relacionadas (Inicial – final). Se concluyó que al aplicar los diferentes agentes blanqueadores que contienen peróxido de hidrogeno no se encontraron diferencias estadísticamente significativas entre los grupos; sin embargo, todos los grupos experimentales presentaron diferencias antes y después de la aplicación de los agentes blanqueadores. / The objective of this research was to compare in vitro the changes in the surface roughness of the tooth structure, generated by different bleaching agents containing hydrogen peroxide (HP). The study detected 50 specimens obtained from bovine teeth, sectioned into dental blocks (7 mm x 7 mm x 7 mm) and prepared to perform an initial reading of surface roughness (Ra), using a profilometer. The samples were randomly divided into 5 groups (n= 10) according to the whitening agent to which they were exposed: group 1: Whiteness HP Maxx 35%, group 2: Opalescent Boost 40% HP, group 3: Opalescent Go 10% HP, group 4: Whiteness Perfect with 10% carbamide peroxide (CP) as positive control and group 5: negative control, with physiological saline. At the end of the bleaching stage, the samples were kept in physiological saline solution; Finally, some profilometric measurements were performed to determine the postbleaching surface roughness parameters. The SPSS® 27.0 statistical package was used for statistical analysis. To identify whether the data follow a normal distribution, the Shapiro Wilk test was used (p > 0.05), then the non-parametric Wilcoxon test was applied for related samples (Initial – final). It is concluded that when applying the different whitening agents containing hydrogen peroxide, no statistically significant differences were found between the groups; however, all experimental groups presented differences before and after the application of the whitening agents.

No / Vitiligo is characterized by a mostly progressive loss of the inherited skin color. The cause of the disease is still unknown, despite accumulating in vivo and in vitro evidence of massive oxidative stress via hydrogen peroxide (H2O2) and peroxynitrite (ONOO−) in the skin of affected individuals. The most favored hypothesis is based on autoimmune mechanisms. Since depletion of the essential amino acid l-tryptophan (Trp) severely affects various immune responses, we here looked at Trp metabolism and signaling in these patients. Our in vivo and in vitro data revealed total absence of epidermal Trp hydroxylase activities and the presence of H2O2/ONOO− deactivated indoleamine 2,3-dioxygenase. Aryl hydrocarbon receptor signaling is severely impaired despite the ligand (Trp dimer) being formed, as shown by mass spectrometry. Loss of this signal is supported by the absence of downstream signals (COX-2 and CYP1A1) as well as regulatory T-lymphocytes and by computer modeling. In vivo Fourier transform Raman spectroscopy confirmed the presence of Trp metabolites together with H2O2 supporting deprivation of the epidermal Trp pool by Fenton chemistry. Taken together, our data support a long-expressed role for in loco redox balance and a distinct immune response. These insights could open novel treatment strategies for this disease.—Schallreuter, K. U., Salem, M. A. E. L., Gibbons, N. C. J., Maitland, D. J., Marsch, E., Elwary, S., Healey, A. R. Blunted epidermal l-tryptophan metabolism in vitiligo affects immune response and ROS scavenging by Fenton chemistry, part 2: epidermal H2O2/ONOO−-mediated stress in vitiligo hampers indoleamine 2,3-dioxygenase and aryl hydrocarbon receptor-mediated immune response signaling.

[pt] Água produzida (AP) é uma das fases geradas a partir da separação trifásica obtida após a extração do petróleo e gás e constitui um efluente industrial. O gerenciamento do seu tratamento para descarte face a alta vazão típica e sensibilidade dos ecossistemas marinhos, é um desafio para empresas que lidam com este tipo de fluido, principalmente na extração offshore. Como este efluente tem uma composição química complexa e variável chegando em até 500 mg/L de compostos orgânicos solúveis em água (WSO), os quais não são facilmente removidos pelos tratamentos físico-químicos convencionais como coagulação e floculação, diversas alternativas de tratamento são adotadas a fim de conseguir eliminar ao máximo óleos e micropartículas de sólidos presentes. Para tal, a AP deve ser tratada antes de ser lançada ao mar ou reutilizada no processo. Contudo, nem sempre as etapas do tratamento conseguem funcionar de maneira ótima para atender a qualidade ambiental regulatória, de modo que a busca por novos processos de tratamento segue sendo de interesse geral. Neste trabalho foram testados processos de oxidação catalisada com íons Fe para incrementar a degradação de WSO, usando amostras reais de AP da Bacia de Campos (RJ, Brasil). Os melhores resultados foram obtidos nas seguintes condições de H2O2 em dose de 1x sem necessidade de catalisador (Fe2+). Nessas ocorreu uma redução de 66 por cento dos orgânicos solúveis, suficiente para manter conformidade com as exigências das normas ambientais para descarte de AP no mar. / [en] Produced water (PW) is one of the phases generated from the three-phase separation obtained after the extraction of oil and gas and constitutes an industrial effluent. The management of its treatment for disposal due to the typical high flow and sensitivity of marine ecosystems is a challenge for companies that deal with this type of fluid, especially in offshore extraction. Since this effluent has a complex and variable chemical composition reaching up to 500 mg/L of water-soluble organic compounds (WSO), which are not easily removed by conventional physicochemical treatments such as coagulation and flocculation, several treatment alternatives are adopted in order to eliminate as much as possible oils and microparticles of solids present. To reach this goal, the PW must be treated before being released into the sea or reused in the process. However, the treatment stages are not always able to function optimally to meet the regulatory environmental quality, so the studies for new treatment processes continues to be part of general interest. In this work, Fe ion-catalyzed oxidation processes were tested to increase WSO degradation, using real PW samples from the Campos Basin (RJ, Brazil). The best results were obtained under the following conditions of H2O2 at a dose of 1x without the need for catalyst (Fe2+). In these, there was a 66 percent reduction in soluble organics, sufficient to maintain compliance with the requirements of environmental standards for water discharge.