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Research and evaluation of iron impact on sludge digestion process / Geležies poveikio dumblo pūdymo procesui tyrimai ir vertinimasOfverstrom, Svetlana 19 February 2014 (has links)
Research and evaluation of effect of traditional (iron salts) and alternative iron source (ochre) on anaerobic digestion of sludge mixture process have been made in dissertation. Research has been made in two European countries: Lithuania and Sweden. Sludge mixture used for the experiments was from biological phosphorus removal plants; ochre originated from groundwater treatment plants. Case study, laboratory and pilot-scale experiments have been made for the complex evaluation of impact of ochre on sludge digestion process. Standard and specific methodics were used for the evaluation of results. Based on results technology for using of ochre for the improving of the anaerobic digestion process at the treatment plants with biological phosphorus treatment has been proposed. / Disertacijoje nagrinėjamas ir vertinamas tradicinio (geležies druskų) ir alternativaus geležies šaltinio (geležies paplavų) poveikis anaerobinio dumblo mišinio pūdymo procesui. Tyrimai buvo atlikti dviejose Europos Sąjungos šalyse: Lietuvoje ir Švedijoje. Tyrimams dumblo mišinys imtas iš biologinio fosforo šalinimo įrenginių; geležies paplavos – iš požeminio vandens gerinimo įrenginių. Siekiant kompleksiškai įvertinti geležies paplavų įtaką dumblo pūdymo procesui, buvo atlikti natūriniai, laboratoriniai ir pusiau gamybiniai tyrimai. Darbe panaudotos standartinės ir specifinės pūdymo proceso kokybės nustatymo metodikos. Remiantis gautais rezultatais buvo pasiūlyta technologinė geležies paplavų panaudojimo dumblo apdorojimo ūkyje, skirta nuotekų valymo įrenginiams su biologiniu fosforo šalinimu.
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Geležies poveikio dumblo pūdymo procesui tyrimai ir vertinimas / Research and evaluation of iron impact on sludge digestion processOfverstrom, Svetlana 19 February 2014 (has links)
Disertacijoje nagrinėjamas ir vertinamas tradicinio (geležies druskų) ir alternativaus geležies šaltinio (geležies paplavų) poveikis anaerobinio dumblo mišinio pūdymo procesui. Tyrimai buvo atlikti dviejose Europos Sąjungos šalyse: Lietuvoje ir Švedijoje. Tyrimams dumblo mišinys imtas iš biologinio fosforo šalinimo įrenginių; geležies paplavos – iš požeminio vandens gerinimo įrenginių. Siekiant kompleksiškai įvertinti geležies paplavų įtaką dumblo pūdymo procesui, buvo atlikti natūriniai, laboratoriniai ir pusiau gamybiniai tyrimai. Darbe panaudotos standartinės ir specifinės pūdymo proceso kokybės nustatymo metodikos. Remiantis gautais rezultatais buvo pasiūlyta technologinė geležies paplavų panaudojimo dumblo apdorojimo ūkyje, skirta nuotekų valymo įrenginiams su biologiniu fosforo šalinimu. / Resarch and evaluation of effect of traditional (iron salts) and alternative iron source (ochre) on anaerobic digestion of sludge mixture process have been made in dissertation. Research have been made in two European countries: Lithuania and Sweden. Sludge mixture used for the experiments was from biological phosphorus removal plants; ochre originated from groundwater treatment plants. Case study, laboratory and pilot-scale experiments have been made for the complex evaluation of impact of ochre on sludge digestion process. Standard and specific methodics were used for the evaluation of results. Based on results technology for using of ochre for the improving of the anaerobic digestion process at the treatment plants with biological phosphorus treatment have been proposed.
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Compréhension des mécanismes de biodétérioration des matériaux cimentaires dans les réseaux d'assainissement : étude expérimentale et modélisation / Understanding of cementitious materials biodeterioration in sewer networks : experimental study and modellingGrandclerc, Anais 16 October 2017 (has links)
Des détériorations importantes sont observées dans les réseaux d’assainissement en béton en raison de la présence d’hydrogène sulfuré (H2S). Différentes études ont montré qu’un environnement riche en hydrogène sulfuré entraîne, au contact de surfaces cimentaires, la sélection de bactéries sulfo-oxydantes (bactéries capables d’oxyder des composés soufrés réduits), menant à la production d’acide sulfurique. Cet acide détériore localement les réseaux par dissolution et recomposition minéralogique de la matrice cimentaire (formation de gypse et d’ettringite). Les réseaux ne collectent alors plus correctement les eaux usées et ce phénomène provoque donc des travaux de rénovation onéreux. Dans ce contexte, des solutions plus performantes que celles mises en place actuellement doivent être étudiées. L’objectif du projet FUI DURANET dans lequel s’inscrit cette thèse vise à proposer un essai accéléré et à développer un modèle.La mise en place d’essais abiotiques a permis de démontrer que cette première étape n’est pas l’étape limitante du phénomène de biodétérioration. En effet, le pH de surface des matériaux cimentaires adapté au développement microbien est rapidement atteint lorsqu’ils sont mis au contact de l’hydrogène sulfuré à une concentration élevée (100 ppm), quel que soit le matériau cimentaire considéré (mortiers à base de ciments CEM I, CEM III, CEM IV, CEM V, CAC et CSS). La modélisation de l’attaque par l’acide sulfurique et la mise en place d’un essai représentatif et accéléré ont ensuite été abordées pour prédire la durabilité des différents matériaux cimentaires de l’étude. Pour l’essai, différentes techniques d’ensemencement des microorganismes à la surface des matériaux cimentaires ont été comparées, afin de déterminer laquelle mène à la meilleure reproduction des conditions d’un réseau d’assainissement et à l’accélération des mécanismes de biodétérioration la plus importante. Ces essais permettent de préconiser l’utilisation de boues activées contenant un consortium de microorganismes, par rapport à l’utilisation de souches de collection, dont l’activité dépend trop fortement de leur adaptabilité aux conditions environnementales. L’ensemble des résultats, obtenus expérimentalement et par modélisation, montre une meilleure résistance des ciments d’aluminate de calcium et une dégradation très importante des ciments Portland face aux mécanismes mis en jeu, en accord avec les essais in-situ / Important deteriorations have been observed in concrete sewers, due to hydrogen sulfide (H2S) presence. H2S is used as nutrients for sulfur-oxidizing bacteria (bacteria able to oxidize the reduced sulfur compounds) and is oxidized into sulfuric acid. This acid attack of concrete leads to cementitious matrix dissolution and expansive products formation (gypsum and ettringite). This phenomenon disturbs the sewer system and conducts to expensive works of rehabilitation. In order to avoid this degradation, a French project named “FUI Duranet” was initiated to propose more efficient solutions. The aim of this thesis is to define a representative and accelerated test as well as a predictive model.Abiotic tests allow stating that this first stage of the biodeterioration mechanisms is not the limiting stage. Indeed, the adapted surface pH of the cementitious materials to bacteria development is quickly reached with a high H2S concentration (100 ppm), whatever the cementitious materials considered (mortars based on CEM I, CEM III, CEM IV, CEM V, CAC, and SSC cements). The chemical-transport modeling of the sulfuric acid attack of cementitious materials and the establishment of a representative and accelerated test have been proposed to predict their service life in these conditions. For the test, different seeding technics have been compared in order to determine which one lead to the better reproduction and acceleration of biodeterioration mechanisms. This test allows recommending the sludge use, which contains a microorganism’s consortium, rather than a collection strain use, whose activity is too dependent on environmental conditions. With the experimental test and the model, the better resistance of the calcium aluminate cement and the important degradation of the Portland cements are quickly confirmed, as highlighted during the field tests
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Management of hydrogen sulphide generation at a Kraft paper millRava, Eleonora Maria Elizabeth 15 September 2008 (has links)
A local integrated pulp and paper Kraft mill had come under pressure from the local communities and mill personnel to reduce the odours that were perceived to be generated at the Farm Dams and irrigation farm situated adjacent to the mill. The typical odours associated with Kraft mills are due to the generation of four reduced sulphur compounds such as hydrogen sulphide (H2S), methyl-mercaptan (CH3SH), dimethyl-sulphide (CH3)2S and dimethyl-disulphide (CH3)2S2. These compounds are collectively referred to as Total Reduced Sulphur (TRS) components which are generated as a direct result of the Kraft pulping and chemical recovery process. These components can either be in the gaseous or aqueous phase depending on the characteristics of the effluent. Gaseous and aqueous TRS profiling of the mill indicated that hydrogen sulphide (H2S) was the main odour component generated and emitted from the Clarifiers and the Treated Effluent Transfer Sump (TETS) at the effluent treatment plant. The hydrogen sulphide (H2S) emission levels were affected by process upsets, sludge removal frequencies, chemical composition of the effluent, Sulphate Reducing Bacteria (SRB) activity, pH and temperature fluctuations. Treatment options such as pH control using slaked lime, dosing of biocides, addition of biomodifiers and/or a sulphate reduction inhibitor were investigated. The use of slaked lime, Ca(OH) 2, for pH control was not practical due to continuous pH fluctuations, increasing the pH would increase the scaling tendencies of the effluent and would also affect the soil cation-anion exchange properties of the irrigated farm land. The use of non-oxidising biocides was effective in reducing SRB activity between 99.2% and 99.8% at dosages between 4 mg/l and 25 mg/l. However, the use of biocides was not considered as a long term treatment option due to the various disadvantages such as the stability of the biocides at fluctuating pH and temperatures, half-life, environmental accumulation, toxicity and costs. The aqueous H2S level was reduced by 79% using different combinations of biomodifiers (nitrates, nitrites, molybdenum). Increasing the dosages of the biomodifiers (> 500mg/l) would be required to increase the reduction of H2S levels by more than 79%. The increased dosages would significantly increase the cost of the treatment programme. The accumulation of nitrates, nitrites and molybdenum could affect the soil texture, cation-anion exchange capacity, permeability, Sodium Absorption Ratio (SAR) and nutrient availability. A more environmentally friendly and cost effective treatment was found using sodium nitrate (biomodifier) together with AQ (sulphate reduction inhibitor). The continuous dosing of 50 mg/l sodium nitrate together with 4 mg/l AQ would be effective in reducing the average aqueous H2S levels (40 mg/l) by at least 92%. This treatment would also be compatible with aeration or oxidation procedures to further increase the removal of H2S to achieve an aqueous H2S level of <1 mg/l. Aeration or oxidation would also increase the dissolved oxygen and COD levels, increase the inhibition of SRB activity and oxidise any reduced sulphur. The dosing of sodium nitrate and AQ to control the generation of H2S is not patented in South Africa. It can, therefore, be used to treat the Kraft mill effluent without violating any intellectual property rights in South Africa. / Dissertation (MSc(Applied Science))--University of Pretoria, 2008. / Chemical Engineering / unrestricted
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Avaliação de mecanismos envolvidos na gastroproteção induzida pelo extrato etanólico da entrecasca da Caesalpinia pyramidalis Tul.Diniz, Polyana Borges França 11 April 2014 (has links)
Caesalpinia pyramidalis, is an endemic plant from the North east of Brazil which present scientifically proven anti-inflamatory, antinociceptive, and gastroprotective activities. This work aimed at evaluating the gastroprotective effect of the extract of Caesalpinia pyramidalis (EECp) bark in acute gastric ulcers induced by ethanol in Wistar rats. The ulcered animals were treated with a dose of 100mg/kg of EECp and L-NAME (nitric acid blocker) and Propargylglycine (hydrogen sulfide blocker). It was evaluated, in all treatments, the role of the gas mediators such as nitric oxide (NO) and hydrogen sulfide (H2S) and also the participation of mast cells and molecules involved in the anti-inflamatory process as iNOS and citocin IL-4. It was observed in the NO evaluation that the treatment with L-NAME was not able to revert the inhibitory effect of EECp on the ulcers induced by ethanol, showing that the EECp does not operate via NO. However, the H2S can operate in the gastro protection of the EECp as its block hindered the gastroprotective effect on the ulcers induced by ethanol. In order to evaluate the mast cells, histological cuts were made with toluidine blue/alcian blue/safranine where different mast cells phenotypes were observed. In all treatments a prevalence of mucous mast cells was observed. The techniques of immunofluorescence and flow cytometry were used to evaluate IL-4 and iNOS. The ulcered animals treated with EECp presented high expression of IL-4 and low expression of iNOS, suggesting an anti-inflammatory activity of EECp. In conclusion, the gastroprotective effect of EECp and its action mechanism are related to H2S in diminishing the oxidative stress, the induced NO synthase, and the positive immunomodulatory effect for IL-4, with the diminution of mucous mast cells during the inflammatory process. / A Caesalpinia pyramidalis, planta endêmica da região do Nordeste é utilizada popularmente para tratamento de diversos distúrbios patológicos e possui ação anti-inflamatória, anti-nociceptiva e gastroprotetora. O objetivo desse trabalho foi avaliar o efeito gastroprotetor do extrato da entrecasca da Caesalpinia pyramidalis (EECp) em modelos de úlcera aguda induzidas por etanol em ratos Wistar. Os animais ulcerados foram tratados com EECp na dose de 100 mg/kg, com L-NAME (bloqueador de óxido nítrico) e Propargilglicina (bloqueador de sulfeto de hidrogênio). Para todos os tratamentos foi avaliado o papel de mediadores gasosos como óxido nítrico (NO) e sulfeto de hidrogênio H2S, e também a participação de mastócitos e de moléculas envolvidas no processo inflamatório como a iNOS e a citocina IL-4. Na avaliação dos de NO observamos que o tratamento com L-NAME não foi capaz de reverter o efeito inibitório da EECp sobre as úlceras induzidas por etanol, demonstrando que o EECp não age pela via do NO. Contudo o H2S pode estar atuando na gastroproteção do EECp pois o seu bloqueio impediu o efeito gastroprotetor sobre as úlceras induzidas por etanol. Para avaliação de mastócitos cortes histológicos foram corados com azul de toluidina/ alcian blue/ safranina onde observamos diferentes fenótipos de mastócitos. Observamos um predomínio de mastócitos mucosos em todos os tratamentos. Para a avaliação de IL-4 e de iNOS foram utilizadas as técnicas de imunofluorescência e citometria de fluxo. Observamos que os animais ulcerados tratados com EECp apresentaram alta expressão de IL-4 e baixa expressão de iNOS, sugerindo uma atividade anti-inflamatória da EECp. Pode-se concluir que o efeito gastroprotetor do EECp e o possível mecanismo de ação, está relacionado ao H2S na diminuição do estresse oxidativo, diminuição do NO sintase induzível e com o efeito imunomodulatório positivo para IL-4, como a diminuição de mastócitos mucosos durante o processo inflamatório.
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In-situ Removal of Hydrogen Sulphide from Landfill Gas : Arising from the Interaction between Municipal Solid Waste and Sulphide Mine Environments within Bioreactor ConditionsLazarevic, David Andrew January 2007 (has links)
This project was compiled in co-operation with the Royal Institute of Technology, Stockholm and Veolia Environmental Services (Australia) at the Woodlawn Bioreactor in NSW, Australia. Hydrogen sulphide is an unwanted component of landfill gas, raising occupational health and safety concerns, whilst leading to acid gas corrosion of power generation equipment and increased emissions of SOx, a primary constituent of acidification. Australian governmental requirements to place a periodic cover over the unused proportion of the tipping surface of landfills and bioreactors create an interesting opportunity for the removal of the hydrogen sulphide component of landfill gas. Using waste materials containing a high concentration of metals as waste cover can enhance the precipitation of sulphur in the form of metal sulphides. The reduction of sulphate via sulphate reducing bacteria is prevalent in sites that have a sizeable inflow of sulphate. The Woodlawn Bioreactor is located in an area where the influence of sulphate has a critical influence of bioreactor performance and production of hydrogen sulphide. Through a series of experimental bioreactors it was established that from the use of metalliferous periodic waste covers, the hydrogen sulphide component of landfill gas was maintained at an extremely low level when compared to the levels of hydrogen sulphide produced in waste under the influence of high sulphate loads with no waste cover. / www.ima.kth.se
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Redução da produção de H2S no fígado de camundongos alimentados com dieta hiperlipídica. / Reduction in H2S production in the livers of mice fed a hyperlipidic diet.Barbosa, Bruna Leoncio 28 May 2019 (has links)
H2S é um gasotransmissor com atua regulando processos fisiológicos e fisiopatológicos. É sintetizado principalmente pelas enzimas cistationinagama-liase (CSE) e cistationina beta-sintase (CBS), ambas dependentes do co-fator 5-fosfato de pirodoxal, e que utilizam o L-cisteína como substrato. Essas enzimas estão presentes no fígado. O camundongo knockout para CBS (CBS KO) apresenta fenótipo de homocistinúria, ou seja, além da homocisteinemia apresenta estresse oxidativo, fibrose e esteatose hepática. Ademais, há estudos in vitro sugerindo um papel desse gás reduzindo a captação de glicose hepática. A hipótese desse projeto é que haja redução precoce da produção de H2S pelo fígado de camundongos alimentados com dieta hiperlipídica (DHL) e esse seja um evento anterior à instalação do fígado gorduroso ou DGHNA associada à obesidade induzida pela DHL, DIO. Para isso, avaliamos a evolução ponderal, consumo alimentar e calórico diários, a tolerância a glicose e a insulina (GTT, ITT e Kitt), a morfohistologia hepática com corantes HE e picrocirius red, expressão proteica e gênica das enzimas CBS e CSE, a quantificação do conteúdo de triglicérides, a deteção de F4/80 e a atividade de enzimas antioxidantes (catalase, GPx e arginase) em amostras de fígado de camundongos machos C57Bl6 alimentados com a DHL por 5 períodos distintos (10, 20, 40, 60 e 80 dias de dieta). Detectamos aumento da massa corporal final a partir de 20 dias de DHL. O consumo alimentar diário foi menor nos animais com a DHL, porém com maior consumo calório do que os respectivos controles. A glicemia basal foi maior nos animais com DHL desde os 10 dias, com exceção o grupo com 40 dias. Houve maior intolerância à glicose desde 10 dias de DHL seguida de resistência à insulina a partir de 20 dias de DHL. Foi detectada presença de vacúolos intracelular nos hepatócitos a partir de 20 dias de DHL, no entanto, a presença de hepatócitos comprometidos foi de aproximadamente 2% aos 20 dias da DHL, cerca de 5% aos 40 dias da DHL e aproximadamente 60% com 60 e 80 dias da DHL. Aos 80 dias de DHL foi detectada balonização de hepatócitos, presença de infiltrado inflamatório identificado pelo aumento da marcação com F4/80, maior detecção de fibras colágenas nos espaços vasculares e aumento da atividade da enzima sérica AST. Houve redução para aproximadamente 50% da produção do H2S nas amostras de fígado dos animais a partir de 40 dias da DHL, porém sem relação clara com as modificações detectadas na expressão das enzimas CBS e CSE. Diante desses dados, concluímos que a DHL leva à intolerância à glicose, seguida de aumento da massa corporal e resistência ao efeito hipoglicemiante da insulina e que o desenvolvimento de fígado gorduroso é um evento mais tardio. Vimos que o espectro da DGHNA desenvolvida apresenta características de esteato-hepatite incipiente, com balonização dos hepatócitos, infiltrado inflamatório presente, discreto aumento de deposição de fibras colágenas e aumento da enzima hepática circulante AST. A redução da produção do gás apareceu após a instalação da resistência à insulina, mas anterior ao estabelecimento da DGHNA. Portanto, concluímos que a alteração na produção hepática do H2S pode ser um evento precoce associado ao desenvolvimento da DGHNA e que merece ser investigado seu potencial papel na progressão de estatose a EHNA com fibrose e cirrose. No entanto, será importante buscar um outro modelo animal para estudo dessa evolução. / Hydrogen sulfide (H2S) is a gaseous signaling molecule that regulates a variety of physiological and pathophysiological processes. It is primarily synthesized by cystathionine-gamma-lyase (CSE) and cystathionine beta-synthase (CBS), which are expressed in the liver, require 5\'-pyrodoxal phosphate as a co-factor, and use L-cysteine as a substrate. Interestingly, CBS knockout (CBS KO) mice present homocystinuria and associated homocysteinemia, as well as oxidative stress, fibrosis and hepatic steatosis. Furthermore, in vitro studies suggest that this gas reduces hepatic glucose uptake. It was hypothesized that mice fed a high fat diet (HFD) would display an early reduction H2S production by the liver and that this event would occur prior to the establishment of fatty liver or NAFLD, which is associated with diet induced obesity (DIO). Towards the goal of gaining a better understanding of H2S production during the onset and progression of DIO, male C57B16 mice were fed a HFD for 10, 20, 40, 60 or 80 days. During the experimental period, weight evolution, daily food and caloric intake, as well as glucose and insulin tolerance (GTT, ITT and Kitt) were evalauted. At the end of each time period hepatocyte morphology was assessed by HE and picrocirius red staining, CBS and CSE gene and protein expression were evaluated, triglyceride content was quantified, F4/80 antigen was detected and antioxidant enzyme (catalase, GPx and arginase) activites were determined. The results showed that mice fed a HFD for 20 days or longer presented an increase in final body weight. All of the HFD groups presented reduced daily food intake, but higher caloric intake, when compared to their respective controls. All of the animals fed a HFD had increased basal glycemia levels, with the exception of the group fed the diet for 40 days. Reduced glucose tolerance and insulin resistance were observed after consuming the HFD for 10 and 20 days, respectively. Intracellular vacuoles were detected in the hepatocytes after 20 days of the HFD. The amount of compromised hepatocytes increased from 2% after 20 days of the HFD, to about 5% after 40 days, to approximately 60% after 60 and 80 days. After consuming the HFD for 80 days, there was an observed ballooning of hepatocytes, increased F4/80 detection indicating the presence of inflammatory infiltrates, increased collagen fiber detection in the vascular spaces, and increased serum AST activity. There was a ~50% reduction in H2S production in the liver samples from animals fed a HFD for 40 days; however, there was no clear relationship with the alterations detected in CBS and CSE gene or protein expression. Based on the results, it was concluded that an HFD promotes glucose intolerance, followed by increased body mass and insulin resistance and that the development of fatty liver occurs later. Additionally, the spectrum of the developed NAFLD presented incipient steatohepatitis characteristics, such as: hepatocyte ballooning, inflammatory infiltrate, a slight increase in collagen fiber deposition, and an increase in circulating liver AST levels. The reduction in H2S gas production appeared after the installation of insulin resistance, but prior to the establishment of NAFLD. Therefore, we conclude that alterations in hepatic H2S production may be an early event associated with the onset of NAFLD and that its potential role in the progression of steatosis and NASH with fibrosis and cirrhosis deserves to be investigated. However, it will be important to evaluate this evolution in other animal models.
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Development of a Conceptual Framework for Adoption and Sustainable Utilization of Biogas as an Alternative Source of Energy for EmmissionUhunamure, Solomon Eghosa 20 September 2019 (has links)
PhD (Geography) / Department of Geography and Geo-Information Sciences / Improved access to modern affordable, sustainable and reliable energy supply is fundamental in the development of any economy and in the achievement of sustainable development goals. However, energy as a resource is increasingly and becoming scare in many countries and subsequently expensive, with a substantial impact on the socio-economic progress, especially in any country that lacks the financial, physical, social and human capital to secure its energy supply. Energy can also be produced though the anaerobic fermentation of biological waste, such as animal excrement, which is methane-rich. Fermentation also produces a nutrient-rich digestate. Biogas can be used for domestic purposes, such as cooking and heating. Furthermore, it can be converted into electricity. Biogas technology is of particular significance in rural households, where energy crisis are common. This thesis therefore aimed at developing an adoption and sustainable utilisation framework of biogas as an alternative source of energy for greenhouse gases emission reduction in the Limpopo Province. The sample involved 72 households with biogas digesters, which were purposively sampled and 128 households without digesters, which were randomly selected. The study was based on the primary data that were elicited using open and closed-ended questionnaires. Empirically, the results of this thesis developed a sustainable, simplified, appropriate and comprehensive framework for biogas adoption and utilisation, including an analysis of important factors that could influence the adoption of this desired technology, for cost-effectiveness and sustainability. / NRF
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The cuticle micromorphology of extant and fossil plants as indicator of environmental conditions : A pioneer study on the influence of volcanic gases on the cuticle structure in extant plants / La morphologie de la cuticule des plantes actuelles et fossiles comme indicateur des conditions environnementales. : Une étude pionnière sur l'influence des gaz volcaniques sur la structure de la cuticule chez les plantes actuellesBartiromo, Antonello 14 February 2012 (has links)
Des observations macroscopiques et microscopiques sur les plantes actuelles et fossiles ont été effectuées. Sur les plantes actuelles ont été effectué des observations relativement aux effets des gaz volcaniques sur l’ultrastructure des cuticules de Pinus halepensis et de Erica arborea récoltés dans l’aire volcanique des Campi Flegrei, Italie. Les observations conduites au TEM sur les cuticules de P. halepensis, influencé et non influencé par les gaz volcaniques, ont montré que : 1) l'épaisseur totale de la CM (cuticule) + CW (paroi pectocellulosique) ne subit pas de variations significatives d'épaisseur ; 2) la cuticule des aiguilles influencée par les gaz volcaniques montre une accumulation d’oxalate de calcium ainsi que 3) un réarrangement des fibrilles disposées parallèlement à la surface. Les observations conduites sur E. arborea ont permis de 1) constater que les épaisseurs totales des cuticules, influencées ou non par les gaz, sont significativement différentes ; 2) en présence de gaz volcaniques la couche externe A2 subit un accroissement d’épaisseur significatif. Par rapport aux macro-restes végétaux fossiles, les localités du Crétacé de Cusano Mutri et Pietraroja ont été étudiées. Le première site fossilifère a permis 1) d’identifier plusieurs taxa appartenant aux conifères; 2) de décrire une nouvelle espèce de conifère: Frenelopsis cusanensis; 3) de trouver l’angiosperme ancestrale Montsechia vidalii. L’étude taxonomique a permis de décrire des entités typiques de la Province Euro-Sinienne. L’étude sédimentologique et systématique montre un climat plutôt tropical-subtropical, des abondants fusains montrant des incendies naturels. / Macroscopical and microscopical observations on extant and fossil plants have been made. Observations on extant plants led to study the effects of volcanic gases on the cuticle ultrastructure of Pinus halepensis and Erica arborea sampled in the volcanic area of Phlegrean Italy. TEM observations on P. halepensis cuticles fumigated or not by volcanic gases revealed: 1) insignificant thickness variations of the cell wall plus cuticle among current- and first-year-old needles of both fumigated and not fumigated trees; 2) a calcium oxalate accumulation in fumigated leaves; 3) moreover, in respect to the cell surface, fibrils are disposed parallel to the surface of the cuticle. In specimens of E. arborea fumigated or not by volcanic gases, 1) the total thickness of cuticles varies significantly; 2) in plants experiencing chronic fumigation the A2 layer increases its thickness. As for fossil plants, the cuticles of Cretaceous Fossil-Lagertätten of Cusano Mutri and Pietraroja have been studied. In the former: 1) numerous taxa belonging to conifers have been identified; 2) the new species Frenelopsis cusanensis has been described; 3) Montsechia vidalii has been found outside of Spain. Taxonomical studies allowed the description of typical Euro-Sinian fossil plants. Sedimentological and taxonomical studies suggest semi-arid or arid conditions in a subtropical or tropical climate. It is worth noting as for Cusano Mutri locality, evidence of wildfire (fusain) suggests a periodic combination of arid periods, high temperatures and lightning strikes.
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Vergiftungsbedingte Todesfälle - Retrospektive Analyse von 316 letalen Intoxikationen des Giftinformationszentrums-Nord / Intoxication related fatalitities - Retrospective study of 316 lethal poisonings of GIZ-Nord Poisons Centre GöttingenKalentzi, Chrissi 25 June 2013 (has links)
Schätzungen über die Gesamtzahl der Vergiftungen in Deutschland belaufen sich auf 150 - 200.000 pro Jahr. In Deutschland machen Vergiftungsfälle 10% der in Notaufnahmen und auf Intensivstationen behandelten Patienten aus. Bis dato gibt es in Deutschland nur wenige strukturiert erfasste epidemiologische Daten von vergiftungsbedingten Todesfällen.
In der vorliegenden Arbeit wurden die vergiftungsbedingten Todesfälle aus dem Giftinformationszentrum-Nord (GIZ-Nord) für den Zeitraum vom 01.01.1996 bis einschließlich 31.12.2009 retrospektiv analysiert. Insbesondere vor dem Hintergrund der Toxikovigilanz konnten folgende Fragen zu Risikokonstellationen für letale Vergiftungen durch diese Arbeit beantwortet werden:
1. Gibt es bei den vergiftungsbedingten Todesfällen jahreszeitliche Schwankungen?
Ja, die vergiftungsbedingten bzw. suizidalen letalen Intoxikationen zeigen jahreszeitliche Schwankungen mit einem maximalen Anteil im Frühling von knapp 30% und dem geringsten Anteil im Herbst mit etwa 20%.
2. Bergen die iatrogen bedingten Vergiftungen ein besonderes Mortalitätsrisiko?
Ja, die iatrogenen Vergiftungen weisen die höchste Mortalitätsrate mit knapp 5 ‰ aller iatrogenen Expositionen auf, vor allem bei parenteraler Arzneimittelapplikation.
3. Stellen Adoleszente (Heranwachsende und Jugendliche) und Senioren über 70 Jahre besonders gefährdete Altersgruppen für letale Intoxikationen dar?
Ja, beide Populationen stellen besondere Risikogruppen für vergiftungsbedingte Todesfälle dar.
Vor allem männliche Heranwachsende repräsentieren eine Risikogruppe für letale Intoxikationen durch Abusus. 30% aller vergiftungbedingten Todesfälle durch Abusus sind bei männlichen Jugendlichen aufgetreten.
Senioren (Männer und Frauen) über 70 Jahre sind eine im hohen Maß gefährdete Altersgruppe für letale Vergiftungen. Einerseits ist die relative Mortalitätsrate bezogen auf alle Expositionen dieser Altersgruppe mit knapp 6 ‰ am höchsten. Andererseits zeigen die suizidalen Intoxikationen bei den Senioren eine zunehmende Tendenz. Außerdem bilden Senioren mit einem Anteil von 24% die Gruppe mit dem größten Anteil an den letalen nicht suizidalen Intoxikationen. Mehr als 70% der akzidentellen letalen Intoxikationen und 50% der letalen Vergiftungen durch Verwechslungen betreffen Senioren, dabei sind Frauen mehr als 3fach häufiger betroffen als Männer.
Darüber hinaus sind Senioren durch Aspiration schäumender, prinzipiell niedrig toxischer Kosmetika und tensidhaltiger Chemikalien besonders gefährdet.
4. Gibt es bei den gewerblichen Expositionen besondere Risikokonstellationen?
Ja, die gewerblichen Expositionen, die mit einer hohen Männerlastigkeit auftreten, bergen eine hohe letale Intoxikationsgefahr. Vor allem bei den gewerblichen inhalativen Expositionen von toxischen Reizgasen besteht eine Gefährdung für die betroffenen Beschäftigten, aber auch für die nicht selbstgeschützten Ersthelfer: 6% der inhalativen gewerblichen Intoxikationen durch Schwefelwasserstoff endeten letal.
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