Yes / The development of cardiovascular disease (CVD) is the main cause of death among chronic kidney disease (CKD) patients (1). Endothelial injury and dysfunction are critical steps in atherosclerosis, a major CVD (2). Increased production of reactive oxygen species (ROS) has been associated with the pathogenesis of cardiovascular diseases such as atherosclerosis, hypertension and heart failure (3). However, hydrogen peroxide (H2O2) modulates endothelial cell function by intricate mechanisms. Ambient production of O2.− and subsequently H2O2 at low levels, maintained via basal activity of pre-assembled endothelial NAD (P) H oxidases (4). Endothelial cells play an important regulatory role in the circulation as a physical barrier and as a source of a variety of regulatory substances. Dysfunction of the vascular endothelium is thus leading to atherosclerosis which is characterised by overexpression of adhesion molecule expression, comprising vascular cell adhesion molecule 1(VCAM1). This adhesion molecule has been found to be up-regulation in human atherosclerotic lesions. The aim of this study is to evaluate the effect of H2O2 on the endothelial cells adhesion molecules expression. Primary cultures of Human Umbilical Vascular Endothelial Cells (HUVECs) will be maintained in endothelial growth medium supplemented with penicillin-streptomycin and supplement mix of fetal calf serum in a 37C humidified incubator in an atmosphere of 5% v/v CO2. HUVECs will be treated with in the presence and absences of 50 μM of H 2O2 for 2, 6, 12 and 24 h. Intracellular superoxide anion production in HUVECs will be detected by using p-Nitro Blue Tetrazolium (NBT) assay to demonstrate whether H2O2 induce the generation of superoxide anions intracellularly in HUVECs. The formation of blue formazan will be measured spectrophotometrically at 570 nm. Total RNA will be extracted from non-treated and treated cells and RNA quantity and quality will be checked by OD260/280 measurements. VCAM-1 mRNA expression will be assessed using RT-PCR. Our results show that H2O2 could potentially significantly induce EC activation through increased mRNA expression of ICAM-1 adhesion molecules in cultured HUVECs. Treatment with N-acetyl cysteine (NAC) (bulk/nano form) could significantly attenuate the effect of H2O2 administration on adhesion molecule protein expression. This strongly suggests the role of ROS in the endothelial cell damage sustained. Future work is to find reliable methods to test endothelial function. Non-invasive studies such as brachial ultrasound testing are also needed to determine its predictive value as a potential predictor for cardiovascular disease.

The implementation of nitrate-free emulsions in Boliden's blasting operations prompted an in-depth investigation into the accumulation of drill cuttings following drilling activities. This master's thesis aimed to understand the contributing factors and quantify drill cuttings, particularly in view of the planned introduction of a new explosive compound. The focal points of the study were the Boliden Kankberg and Garpenberg mines, where a rich variety of data sources were harnessed. The research encompassed a thorough literature review highlighting enduring challenges in drilling and factors that influenced cuttings transport. The study delved into the complex relationships between drilling parameters, including drilling angle, rate of penetration, lithology, and other variables, examining their role in drill cuttings generation and hole evenness. This thesis was a response to the planned introduction of nitrate-free emulsions in Boliden's blasting operations, catalyzed by concerning observations at the Kankberg mine. These observations revealed a significant presence of residual drill cuttings, which raised concerns about their potential impact on blasting effectiveness. The primary focus was on the Kankberg and Garpenberg mines, allowing for a comprehensive exploration of data mainly obtained by filming the drill holes after drilling. A noteworthy aspect of the study was the development and application of a MATLAB-based image processing code to estimate the volume of residual drill cuttings in drill holes. This quantitative approach served as a robust foundation for the investigation. One key finding of the investigation was the disparity in drill cuttings accumulation between the investigated holes in Garpenberg and Kankberg. The "Working from Backwards" approach, employed at the Kankberg mine, underscored the critical importance of controlled drilling angle and rate of penetration in mitigating drill cuttings and achieving uniform drilling outcomes. While this research shed light on these factors, further exploration was needed to fully grasp their intricacies and identify additional variables influencing drill cuttings and hole evenness. These findings offered vital guidance for the development of strategies and practices to enhance drilling operations in the future. Additionally, cluster analysis results emphasized the pivotal role of lithological characteristics in drill cuttings generation. The study provided practical recommendations, including the identification of lithological variations through enhanced mapping, the adjustment of drilling parameters, and the optimization of drilling methods tailored to specific lithologies. / <p>Successful</p>

Neste trabalho estudou-se as propriedades ópticas do complexo Európio- Tetraciclina (EuTc), determinando as melhores condições para se obter uma formação eficiente do complexo. Parâmetros ópticos como absorção, emissão, tempo de vida e índice de refração foram obtidos. Variação da concentração de európio no complexo, da temperatura, pH ótimo e tempo de reação das soluções foram analisados. Um aumento na banda de emissão do európio foi observado com adição de peróxido de hidrogênio (HP) na solução. As amostras foram preparadas com pH neutro e a luminescência visível do lantanídeo foi detectada após uma incubação das amostras por 30 min. Um método direto para determinação de peróxido de uréia (PHU) e colesterol, em solução, usando a fluorescência do complexo EuTc é descrito. Os resultados mostram que o complexo é ainda mais sensível para o peróxido de uréia, aumentando a intensidade de emissão em até 40 vezes, do que para o peróxido de hidrogênio, que proporciona um aumento máximo de 15 vezes, quando comparados ao EuTc puro. É reportado também, pela primeira vez, que para a determinação do colesterol total, utilizando-se a sonda EuTc, não há necessidade de adição de enzima na solução, além de ser capaz de detectar frações de colesterol (LDL, VLDL e HDL), também sem adição de outros reagentes. Esse método mostra que o complexo pode ser usado como biossensor de alta sensibilidade, boa precisão, resposta rápida, baixo custo e resultados reprodutíveis para a determinação direta do peróxido de hidrogênio, do peróxido de uréia, de colesterol e LDL e para a determinação indireta da glicose. Uma proposta para a construção de um protótipo de equipamento para medidas de emissão do európio, miniaturizado, portátil, e de baixo custo, que possa ser utilizado com maior facilidade e rapidez, é apresentado. / In this work was studied the optical properties of Europium-Tetracycline complex (EuTc), determining the best conditions to obtain an efficient complex formation. Optical parameters as absorption, emission, lifetime and refractive index were obtained. Variation of europium complexes concentration, temperature, optimal pH and solutions time reaction were analyzed. An increase in the europium emission band was observed with the addition of hydrogen peroxide (HP) in the solution. The samples were prepared with neutral pH and the lanthanide visible luminescence was detected after a samples incubation of 30 min. A direct method to determine urea hydrogen peroxide (PHU) and cholesterol, in solution, using a fluorescent EuTc complex is described. The results show that the complex is more sensitive for urea hydrogen peroxide, it is over fortyfold higher, while for hydrogen peroxide the increasing is fifteenfold higher when compared to pure EuTc complex emission intensity. It is also reported, for the first time, for the determination of cholesterol total, using the EuTc probe, the enzymatic reaction is not necessary, and also is possible to detect cholesterol fractions (LDL, VLDL and HDL), without the addition of other reagents. This method shows that the complex can be used as a biossensor of high sensibility, good accuracy, fast response, low cost and reproducible results to direct determination of hydrogen peroxide, urea hydrogen peroxide, cholesterol and LDL, and to indirect determination of glucose. A prototype for the construction of miniaturized equipment, portable, low cost, easier and faster to be used, is presented.

Yau Ho Yan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 131-144). / Abstracts in English and Chinese. / DECLARATION --- p.I / ACKNOWLEDGEMENTS --- p.II / ENGLISH ABSTRACT --- p.III / CHINESE ABSTRACT --- p.VI / Chapter Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Oxidative Stress --- p.1 / Chapter 1.1.1 --- Historical Background of reactive oxygen/nitrogen species --- p.1 / Chapter 1.1.2 --- What is Oxidative Stress? --- p.3 / Chapter 1.1.3 --- Reactive Oxygen Species (ROS) --- p.4 / Chapter 1.1.3.1 --- Superoxide anion (02-) --- p.4 / Chapter 1.1.3.2 --- Hydrogen peroxide (H202) --- p.5 / Chapter 1.1.3.3 --- Hydroxyl radical --- p.6 / Chapter 1.1.3.4 --- Nitric oxide (NO) --- p.7 / Chapter 1.2 --- Cardiovascular System --- p.8 / Chapter 1.2.1 --- Enzymatic and Non-enzymatic Sources of ROS in Cardiovascular System --- p.8 / Chapter 1.2.1.1 --- NADPH oxidase --- p.8 / Chapter 1.2.1.2 --- Hypoxanthine-Xanthine oxidase (HX-XO) --- p.9 / Chapter 1.2.1.3 --- Nitric oxide synthase (NOS) --- p.10 / Chapter 1.2.1.4 --- Mitochondrial electron transport chain (ETC) --- p.11 / Chapter 1.2.1.5 --- Cyclooxygenase --- p.11 / Chapter 1.2.1.6 --- Lipoxygenae --- p.12 / Chapter 1.2.1.7 --- Endoplasmic reticulum --- p.12 / Chapter 1.2.2 --- ROS/RNS Scavenging Systems --- p.13 / Chapter 1.2.2.1 --- Superoxide dismutase (SOD) --- p.13 / Chapter 1.2.2.2 --- Catalase --- p.14 / Chapter 1.2.2.3 --- Glutathione peroxidase --- p.15 / Chapter 1.2.2.4 --- Non-enzymatic antioxidants --- p.15 / Chapter 1.2.3 --- Factors that stimulate ROS production in cardiovascular system --- p.18 / Chapter 1.2.3.1 --- Oxygen tension --- p.18 / Chapter 1.2.3.2 --- "Flow, Shear, and Stretch as an initial stimulus for endothelial oxidant signalling" --- p.18 / Chapter 1.2.3.3 --- Activation of rennin-angiotensin system promote oxidative stress in cardiovascular system --- p.19 / Chapter 1.2.3.4 --- Regulation of vascular ROS production by vasoactive substances --- p.19 / Chapter 1.2.4 --- Regulation of vascular tone in Cardiovascular System by ROS/RNS --- p.20 / Chapter 1.2.4.1 --- Regulation of vascular tone --- p.20 / Chapter 1.2.5 --- Pathophysiological Effects of ROS --- p.23 / Chapter 1.2.5.1 --- Cellular injury by lipid peroxidation --- p.23 / Chapter 1.2.5.2 --- Role of ROS in immune defence --- p.23 / Chapter 1.2.5.3 --- Redox regulation of cell adhesion --- p.24 / Chapter 1.2.6 --- Evidences from Clinical Studies of Oxidative Stress-Related Vascular Diseases --- p.25 / Chapter 1.2.6.1 --- Hyperlipidaemia --- p.25 / Chapter 1.2.6.2 --- Hypertension --- p.25 / Chapter 1.2.6.3 --- Chronic heart failure (CHF) --- p.26 / Chapter 1.2.6.4 --- Chronic renal failure (CRF) --- p.26 / Chapter 1.2.6.5 --- Atherosclerosis --- p.27 / Chapter 1.2.6.6 --- Ischemia/reperfusion (I/R) injury --- p.27 / Chapter 1.2.7 --- Role of Vascular Endothelium in Oxidative Stress --- p.29 / Chapter 1.2.8 --- Role of Ca in oxidative stress in cardiovascular system --- p.29 / Chapter 1.2.8.1 --- Calcium Signaling in Vascular Endothelial Cells --- p.30 / Chapter 1.2.9 --- ROS effect on endothelial Ca2+ --- p.31 / Chapter 1.2.9.1 --- Multiple targets of ROS on intracellular Ca2+ mobilization --- p.32 / Chapter 1.2.9.2 --- Reports of H202-induced Ca2+ release in various cell types --- p.33 / Chapter 1.2.9.3 --- Reported effects of H202 on agonist-induced Ca2+ signal --- p.34 / Chapter 1.2.9.4 --- Differences between macrovessels and microvessels --- p.34 / Chapter 1.3 --- TRP Channel --- p.41 / Chapter 1.3.1 --- Discovery of Drosophila TRP --- p.41 / Chapter 1.3.2 --- Mammalian TRP subfamily --- p.41 / Chapter 1.3.3 --- General topology of TRP channel --- p.42 / Chapter 1.3.4 --- Interactions of oxidative stress with TRP channels --- p.44 / Chapter 1.3.5 --- The role of TRPC3 and TRPC4 in oxidative stress --- p.44 / Chapter 1.3.6 --- TRPM subfamily --- p.44 / Chapter 1.3.6.1 --- Expression of TRPM2 --- p.45 / Chapter 1.3.6.2 --- Dual Role of TRPM´2ؤChannel and Enzyme --- p.45 / Chapter 1.3.6.3 --- Regulatory mechanisms of TRPM2 --- p.46 / Chapter 1.3.6.3.1 --- ADP-ribose (ADPR) directly regulating --- p.46 / Chapter 1.3.6.3.2 --- NAD regulating --- p.46 / Chapter 1.3.6.3.3 --- Oxidative stress regulating independent of ADPR or NAD --- p.47 / Chapter 1.4 --- Cell Death Induced by Oxidative Stress --- p.48 / Chapter 1.4.1 --- Redox status as a factor to determine cell death --- p.48 / Chapter 1.4.2 --- Role of TRPM2 in oxidative stress-induced cell death --- p.48 / Chapter 1.5 --- Aims of the Study --- p.49 / Chapter Chapter 2: --- Materials and Methods --- p.50 / Chapter 2.1 --- Functional Characterization of TRPM2 by Antisense Technique --- p.50 / Chapter 2.1.1 --- Restriction Enzyme Digestion --- p.50 / Chapter 2.1.2 --- Purification of Released Inserts and Cut pcDNA3 Vectors --- p.51 / Chapter 2.1.3 --- "Ligation of TRPM2 Genes into Mammalian Vector, pcDNA3" --- p.52 / Chapter 2.1.4 --- Transformation for the Desired Clones --- p.52 / Chapter 2.1.5 --- Plasmid DNA Preparation for Transfection --- p.53 / Chapter 2.1.6 --- Confirmation of the Clones --- p.53 / Chapter 2.1.6.1 --- Restriction Enzymes Strategy --- p.53 / Chapter 2.1.6.2 --- Polymerase Chain Reaction (PCR) Check --- p.54 / Chapter 2.1.6.3 --- Automated Sequencing --- p.55 / Chapter 2.2 --- Establishing Stable Cell Lines --- p.56 / Chapter 2.2.1 --- Cell Culture --- p.56 / Chapter 2.2.2 --- Geneticin Selection --- p.57 / Chapter 2.3 --- Expression of TRPM2 in Transfected and non-Transfected H5V Cells --- p.57 / Chapter 2.3.1 --- Protein Sample Preparation --- p.57 / Chapter 2.3.2 --- Western Blot Analysis --- p.58 / Chapter 2.3.3 --- Protein Expression Analysis --- p.59 / Chapter 2.4 --- "Immunolocalization of TRPM2 in Human Heart, Cerebral Artery, Renal, Hippocampus and Liver" --- p.59 / Chapter 2.4.1 --- Paraffin Section Preparation --- p.59 / Chapter 2.4.2 --- Immunohistochemistry --- p.60 / Chapter 2.5 --- [Ca2+ ］i Measurement in Confocal Microscopy --- p.62 / Chapter 2.5.1 --- Cytosolic Ca2+ measurement --- p.62 / Chapter 2.5.2 --- Measuring the Ca2+ in the Internal Calcium Stores --- p.63 / Chapter 2.5.3 --- Data Analysis --- p.64 / Chapter 2.6 --- Examining Cell Death Induced by H2O2 by DAPI Staining --- p.65 / Chapter 2.6.1 --- DAPI Staining --- p.65 / Chapter Chapter 3: --- Results --- p.66 / Chapter 3.1 --- Superoxide Anion-Induced [Ca 2+]i rise in H5V Mouse Heart Microvessel Endothelial Cells --- p.66 / Chapter 3.1.1 --- Superoxide Anion-induced [Ca2+ ]i Rise --- p.66 / Chapter 3.1.2 --- Effect of Catalase on the Superoxide Anion-induced [Ca2+]i］］ Rise --- p.66 / Chapter 3.1.3 --- IP3R inhibitor Inhibits Superoxide anion-induced [Ca 2+]i Rise --- p.67 / Chapter 3.1.4 --- Effect of Phospholipase A2 Inhibitor on Superoxide anion- induced [Ca2+]i Rise --- p.67 / Chapter 3.1.5 --- Effect of Hydroxyl Radical Scavenger on Superoxide Anion- induced [Ca2+]i Rise --- p.68 / Chapter 3.2 --- Hydrogen Peroxide-induced Ca2+ Entry in Mouse Heart Microvessel Endothelial Cells --- p.74 / Chapter 3.2.1 --- Hydrogen Peroxide Induces [Ca2 +]i rise in H5V Mouse Heart Microvessel Endothelial Cells --- p.74 / Chapter 3.2.2 --- Hydrogen Peroxide Induces [Ca 2+]i rise in two phases (Rapid and Slow response) --- p.74 / Chapter 3.2.3 --- Hydrogen Peroxide Induces [Ca 2+]i rise in a Extracellular Ca + Concentration Dependent Manner --- p.77 / Chapter 3.3 --- Hydrogen Peroxide Reduces Agonist-induced [Ca2+]i rise --- p.79 / Chapter 3.3.1 --- Hydrogen Peroxide Reduces ATP-induced [Ca2+ ]i rise in a H2O2 Concentration Dependent Manner --- p.79 / Chapter 3.3.2 --- Hydrogen Peroxide Reduces ATP-induced [Ca 2+]i rise in a H2O2 Incubation Time Dependent Manner --- p.79 / Chapter 3.3.3 --- Hydrogen Peroxide Reduces the ATP-induced Intracellular Ca2+ Release --- p.80 / Chapter 3.3.4 --- XeC Inhibited H202-induced [Ca2+]i rise --- p.80 / Chapter 3.3.5 --- Hydrogen Peroxide Partially Depletes Internal Ca2+ Stores --- p.81 / Chapter 3.4 --- Dissecting Signal Transduction Pathways in H202-induced [Ca2+]i rise --- p.82 / Chapter 3.4.1 --- Effect of Phospholipase C Inhibitor on H202-induced [Ca2 +]i rise --- p.82 / Chapter 3.4.2 --- Effect of Phospholipase A2 Inhibitor on H202-induced [Ca 2+]i rise --- p.83 / Chapter 3.4.3 --- Effect of hydroxyl radical scavenger on H2O2-induced [Ca 2+]i rise --- p.83 / Chapter 3.5 --- Functional Role of TRPM2 Channel in H202-induced [Ca2+]i Rise in H5V Cells --- p.92 / Chapter 3.5.1 --- Expression of TRPM2 and the Effect of TRPM2 Antisense Construct on TRPM2 Protein Expression --- p.92 / Chapter 3.5.2 --- Effect of Antisense TRPM2 on H202-induced Ca2+ Entry --- p.94 / Chapter 3.6 --- H202-induced Cell Death --- p.101 / Chapter 3.7 --- Expression Pattern of TRPM2 Channel in Vascular System --- p.104 / Chapter 3.7.1 --- Immunolocalization of TRPM2 in Human Cerebral Arteries --- p.104 / Chapter 3.7.2 --- Immunolocalization of TRPM2 in Human Cardiac Muscles --- p.105 / Chapter 3.7.3 --- Immunolocalization of TRPM2 in Human Kidney --- p.105 / Chapter Chapter 4: --- Discussion --- p.113 / Chapter 4.1 --- Oxidative modification of Ca2+ homeostasis --- p.113 / Chapter 4.2 --- Pathophysiological effects of ROS on endothelium --- p.113 / Chapter 4.3 --- Effects of ROS on microvascular endothelial Ca2+ reported by other investigators --- p.115 / Chapter 4.4 --- Studies of the effect of HX-XO on cytosolic [Ca2+]i --- p.116 / Chapter 4.4.1 --- Role of 0´2Ø- and H202 in HX-XO-induced [Ca2+]i elevation --- p.116 / Chapter 4.4.2 --- IP3R involvement in HX-XO-evoked Ca + movements in H5V cells --- p.118 / Chapter 4.4.3 --- PLA2 involvement in HX-XO experiment --- p.119 / Chapter 4.5 --- Studies of the effect of direct H202 application on cytosolic [Ca2+]i --- p.120 / Chapter 4.5.1 --- Hydrogen Peroxide Induced [Ca2 +]i rise in a Extracellular Ca2 + Concentration Dependent Manner --- p.120 / Chapter 4.5.2 --- Hydrogen Peroxide Induced [Ca 2+]i rise in two phases (Rapid and Slow response) --- p.121 / Chapter 4.6 --- Effect of H202 on ATP-induced Ca2+ response --- p.121 / Chapter 4.6.1 --- H202 inhibited ATP-induced Ca2+ release in a concentration and time dependent manner --- p.121 / Chapter 4.6.2 --- IP3R involvement and store depletion in H202 experiment --- p.123 / Chapter 4.7 --- Dissecting Signal Transduction Pathways in H202-induced [Ca2+]i rise --- p.124 / Chapter 4.7.1 --- PLC involvement in H2O2 experiment --- p.124 / Chapter 4.7.2 --- PLA2 involvement in H2O2 experiment --- p.125 / Chapter 4.7.3 --- Hydroxyl radical did not involve in H2O2 experiment --- p.125 / Chapter 4.8 --- Functional Studies of TRPM2 --- p.127 / Chapter 4.8.1 --- Expression of TRPM2 in H5V on protein level --- p.127 / Chapter 4.8.2 --- TRPM2 involvement in the Ca2+ signalling in response to H2O2 in H5V cells --- p.127 / Chapter 4.9 --- H202 concentration in my projec´tؤphysiological or pathological? --- p.128 / Chapter 4.10. --- H20´2ؤTRPM´2ؤCell death --- p.129 / Chapter 4.11 --- Expression of TRPM2 in human blood vessels and other tissues --- p.130 / References --- p.131

Neste trabalho estudou-se as propriedades ópticas do complexo Európio- Tetraciclina (EuTc), determinando as melhores condições para se obter uma formação eficiente do complexo. Parâmetros ópticos como absorção, emissão, tempo de vida e índice de refração foram obtidos. Variação da concentração de európio no complexo, da temperatura, pH ótimo e tempo de reação das soluções foram analisados. Um aumento na banda de emissão do európio foi observado com adição de peróxido de hidrogênio (HP) na solução. As amostras foram preparadas com pH neutro e a luminescência visível do lantanídeo foi detectada após uma incubação das amostras por 30 min. Um método direto para determinação de peróxido de uréia (PHU) e colesterol, em solução, usando a fluorescência do complexo EuTc é descrito. Os resultados mostram que o complexo é ainda mais sensível para o peróxido de uréia, aumentando a intensidade de emissão em até 40 vezes, do que para o peróxido de hidrogênio, que proporciona um aumento máximo de 15 vezes, quando comparados ao EuTc puro. É reportado também, pela primeira vez, que para a determinação do colesterol total, utilizando-se a sonda EuTc, não há necessidade de adição de enzima na solução, além de ser capaz de detectar frações de colesterol (LDL, VLDL e HDL), também sem adição de outros reagentes. Esse método mostra que o complexo pode ser usado como biossensor de alta sensibilidade, boa precisão, resposta rápida, baixo custo e resultados reprodutíveis para a determinação direta do peróxido de hidrogênio, do peróxido de uréia, de colesterol e LDL e para a determinação indireta da glicose. Uma proposta para a construção de um protótipo de equipamento para medidas de emissão do európio, miniaturizado, portátil, e de baixo custo, que possa ser utilizado com maior facilidade e rapidez, é apresentado. / In this work was studied the optical properties of Europium-Tetracycline complex (EuTc), determining the best conditions to obtain an efficient complex formation. Optical parameters as absorption, emission, lifetime and refractive index were obtained. Variation of europium complexes concentration, temperature, optimal pH and solutions time reaction were analyzed. An increase in the europium emission band was observed with the addition of hydrogen peroxide (HP) in the solution. The samples were prepared with neutral pH and the lanthanide visible luminescence was detected after a samples incubation of 30 min. A direct method to determine urea hydrogen peroxide (PHU) and cholesterol, in solution, using a fluorescent EuTc complex is described. The results show that the complex is more sensitive for urea hydrogen peroxide, it is over fortyfold higher, while for hydrogen peroxide the increasing is fifteenfold higher when compared to pure EuTc complex emission intensity. It is also reported, for the first time, for the determination of cholesterol total, using the EuTc probe, the enzymatic reaction is not necessary, and also is possible to detect cholesterol fractions (LDL, VLDL and HDL), without the addition of other reagents. This method shows that the complex can be used as a biossensor of high sensibility, good accuracy, fast response, low cost and reproducible results to direct determination of hydrogen peroxide, urea hydrogen peroxide, cholesterol and LDL, and to indirect determination of glucose. A prototype for the construction of miniaturized equipment, portable, low cost, easier and faster to be used, is presented.

På pappersmaskin 11 i Hallsta pappersbruk tillverkas högglansigt papper som bleks med väteperoxid. Om väteperoxiden som finns kvar efter blekningen, kallat restperoxid, kommer ut på pappersmaskinen sliter detta på termovalsarna, vilket påverkar slutprodukten. Det finns en bakteriekultur på bruket, bestående av släktet Tepidiphilus som bryter ner väteperoxiden med hjälp av katalas och hindrar den från att komma ut på maskinen. Om bakterierna slås ut, av exempelvis ogynnsamma förhållanden, märks detta genom att restperoxiden ökar. Målet med detta arbete är att försöka identifiera vilka faktorer som påverkar bakterierna och lägga fram ett förslag för hur man kan förhindra uppkomsten av restperoxid. För att utföra detta användes i första hand principalkomponentanalys, samt så studerades hur olika faktorer förändrades i förhållanden till uppkomsten av restperoxid. Ett antal parametrar kunde identifieras baserat på tillgängliga data. Dock kan inga absoluta slutsatser dras då det inte går att bekräfta några teorier med labbförsök eller genom att manipulera processen. De parametrar som tros ha störst påverkan är mek. renat färg, rest-aluminium, grumlighet, manganhalten i vatten, pH för kar K0203, returmälden samt inloppslådan och klorhalterna som uppmätts för mek. renat total klor, RVV1 fri klor, varmvatten total klor och mek. renat fri klor. Dessa parametrar bör därför övervakas framåt, och kan i det fall att restperoxid återigen uppkommer antingen bekräftas eller dementeras deras faktiska påverkan och samspel för bakteriernas välmående. / Paper machine 11 in Hallsta paper mill produces high-gloss paper that is bleached with hydrogen peroxide. If the hydrogen peroxide that remains after the bleaching, called residual peroxide, gets out on the paper machine, this wears down the thermal rollers, which affects the final product.  There is a bacterial culture at the mill, consisting of the genus Tepidiphilus, which breaks down the hydrogen peroxide with the help of catalase and prevents it from getting out to the machine. If the bacteria are killed, for example by unfavourable conditions, this is noticeable by an increase in residual peroxide. The goal of this project is to try to identify which factors affect the bacteria and put forward a proposal for how to prevent the occurrence of residual peroxide. To carry this out, principal component analysis was primarily used, and how different factors changed in relation to the appearance of residual peroxide was studied. Several parameters could be identified based on the available data. However, no conclusive conclusions could be drawn as it is not possible to confirm any theories with lab tests or by manipulating the process. The parameters believed to have the greatest influence are coloration of mechanically cleaned water (mech. water), residual aluminium, turbidity, manganese content of the water, pH for tank K0203, the returning pulp suspension as well as the headbox and the chlorine levels for mech. water total chlorine, RVV1 free chlorine, hot water total chlorine and mech. water free chlorine. These parameters should therefore be monitored going forward, and if residual peroxide occurs again, their possible interactions and actual impact on the well-being of the bacteria can either be confirmed or denied

No description available.

Human neutrophil 5-lipoxygenase (5-LOX) oxidizes arachidonic acid (AA) to 5S-hydro(pero)xy-6E,8Z,11Z,14Z-eicosatetraenoic acid (5-H(p)ETE) and leukotriene (LT)A4, which is further converted to the chemoattractant LTB4. These cells contain also the heme enzyme myeloperoxidase (MPO) producing several potent oxidants such as hypochlorous acid (HOCl). Previously, it was shown that MPO-metabolites influence 5-LOX product formation. Here, we addressed the question, whether a simultaneous activation of MPO and 5-LOX in neutrophils results in comparable changes of 5-LOX activity. Human neutrophils were stimulated with H2O2 or phorbol 12-myristate 13-acetate (PMA) for MPO activation and subsequently treated with calcium ionophore A23187 inducing 5-LOX product formation on endogenous AA. Special attention was drawn to neutrophil vitality, formation of MPO-derived metabolites and redox status. The pre-stimulation with H2O2 resulted in a concentration-dependent increase in the ratio of 5-HETE to the sum of LTB4 + 6-trans-LTB4 in consequence of MPO activation. Thereby no impairment of cell vitality and only a slightly reduction of total glutathione level was observed. An influence of MPO on 5-LOX product formation could be suggested using an MPO inhibitor. In contrast, the pre-stimulation with PMA resulted in different changes of 5-LOX product formation leading to a reduced amount of 5-HETE unaffected by MPO inhibition. Furthermore, impaired cell vitality and diminished redox status was detected after PMA stimulation. Nevertheless, a MPO-induced diminution of LTB4 was obvious. Further work is necessary to define the type of 5-LOX modification and investigate the effect of physiological MPO activators.

3D printers that precisely fuse plastic filament are enabling medical manufacturers to produce high-quality plastic medical devices and implants. However, the low-temperature fusing process implies that post-production sterilization must also occur at a low temperature or destroy the precision of the product. This study characterizes the effects of hydrogen peroxide (H2O2) vapour sterilization on ASTM-compliant tensile samples of polylactic acid, polycaprolactone, and polycarbonate. The sterilization process caused physical deformations in polycaprolactone. Additionally, increases were observed in polycaprolactone and polycarbonate sample thickness, and in polycarbonate sample width. Decreases in E were found in all three materials, while UTS decreased in polycarbonate, and strain at UTS increased in polycaprolactone. The findings demonstrate that the materials can be compatible with H2O2 vapour sterilization, but products must be designed to accommodate for changes that occur due to sterilization. / February 2017

No description available.