A presente pesquisa foi desenvolvida para avaliar as potencialidades das células de combustível como tecnologia em si, inclusive os beneficios econômicos que se podem ter por meio do suprimento de energia elétrica se comparada com o aproveitamento da mesma por meio da rede pública. Além de uma parte descritiva do estado de arte da tecnologia, a presente dissertação foi focada em duas partes: a primeira trata de um estudo experimental onde uma célula, a membrana polimérica, foi conectada a um inversor, permitindo assim de fornecer energia elétrica na rede pública. Na segunda parte foi realizada uma avaliação engenhero-econômica com uma Célula de Combustível de Ácido Fosfórico para o aproveitamento da energia elétrica com cogeração de calor para as condições de mercado brasileiro. O primeiro estudo mostrou como seja possível abastecer uma célula (neste caso alimentada por hidrogênio) para fornecer continuamente energia elétrica na rede, onde necessário ou onde seja impossível para o usuário se conectar a rede pública. O segundo estudo, por sua vez, mostrou que atualmente a células de combustível de média temperatura de Ácido Fosfórico (PAFC) não é uma tecnologia ainda madura e que é viável economicamente somente em aplicações de nicho, por exemplo setores indústriais eletro-intensivos e com necessidade de energia termica também. Todavia, projeções futuras baseadas em curvas de aprendizados e a queda do preço do gás natural mostram como a expansão da tecnologia e a possibilidade de acessar um combustível barato podem abrir futuro para a PAFC mundialmente. / This Masters dissertation aims to study technical potentialities of Fuel Cell technology, including the economical benefits that can provide compared with public grid as well. Thus, the dissertation has been focused in two main parts: the first concerns in an experimental approach to supply electrical power to the public grid using a Polymer Electrolyte Membrane Fuel Cell (PEMFC), while the second one presents a global (from an engineering and economic point-of-view) assessment of a Phosphoric Acid Fuel Cell (PAFC) for the co-generation of heat with electrical energy in Brazil. The first study has been accomplished connecting a PEMFC with a power inverter to the public grid. It has been proved experimentally that Fuel Cell is an alternative device that, as long as fuel is fed, may provide electrical energy continuously and more efficiently than traditional devices. The second study has been focused in the so-called Phosphoric Acid Fuel Cell (PAFC) that, being a Medium Temperature Fuel Cell, beyond to supply electrical energy, may be used for co-generation of thermal energy. Through this study it has been showed that, at the current state-of-art, PAFC is is not already a mature technology and it becomes economically viable only for niche market applications, represented by the industrial sectors with high base load power and continuous thermal energy demand. However, accumulated knowledge expressed by learning curve and natural gas shock price caused by possible LNG supplying and shale gas recovery are the two main factors that may turn investment in PAFC profitable worldwide.

Made available in DSpace on 2014-10-09T12:23:11Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:56:29Z (GMT). No. of bitstreams: 1 00636.pdf: 4746331 bytes, checksum: 49aa6e0eb3bdd9da261862a04bcb4b58 (MD5) / Dissertacao (Mestrado) / IEA/D / Instituto de Quimica, Universidade de Sao Paulo - IQ/USP

Made available in DSpace on 2014-10-09T12:51:44Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:08:36Z (GMT). No. of bitstreams: 0 / Investiga-se a influência de diferentes tratamentos sobre o sistema alumínio com cobertura de óxido de alumínio. A anodização do alumínio em meio de ácido sulfúrico e meio misto de sulfúrico e fosfórico foi empregada para alterar a resistência à corrosão, a espessura, o grau de cobertura e a microdureza do óxido anódico; e a eletrodeposição de ferro no interior óxido anódico em meio de sulfato com tratamento químico de selagem com cério, para alterar a sua condutividade elétrica e a sua resistência à corrosão. Para a eletrodeposição de ferro aplicou-se corrente contínua e pulsada e diversificou-se a composição do eletrólito de Fe(SO4)2(NH4)2.6H2O, com a adição dos ácidos bórico e ascórbico e para o tratamento de selagem, variou-se a concentração do CeCl3. A espectroscopia de energia dispersiva de raios X (EDS), a fluorescência de raios X (FRX) e a análise morfológica por microscopia eletrônica de varredura (MEV) permitiram verificar que, a corrente pulsada eleva o teor de ferro na camada anódica e a presença dos aditivos inibe a oxidação do ferro. As curvas cronopotenciométricas obtidas durante a eletrodeposição de ferro indicaram que a mistura dos ácidos bórico e ascórbico aumentaram a eficiência do processo de eletrodeposição. A espectroscopia de impedância eletroquímica (EIE), medidas de microdureza Vickers (H) e análise morfológica evidenciaram que o tratamento de selagem melhora a resistência à corrosão do filme óxido modificado com ferro. As medidas de impedância elétrica por duas pontas permitiram comprovar o aumento da condutividade elétrica do alumínio anodizado com ferro, mesmo após o tratamento com baixas concentrações de cério. Nanofios de ferro foram preparados utilizando os poros do óxido anódico como matriz. / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

A degradação da interface adesiva em dentina pode acometer tanto a porção resinosa como a porção orgânica da camada híbrida. Evidências indicam que a degradação da porção orgânica pode ocorrer em parte devido a atividade enzimática de proteases da própria dentina. As metaloproteinases da matriz (MMPs) constituem a primeira classe de enzimas relacionada com a degradação da matriz orgânica. É possível que as MMPs, possam ser reativadas durante o procedimento adesivo em conseqüência da queda do pH do meio. Objetivo: Esta investigação teve como objetivos avaliar a influência de soluções desmineralizadoras com diferentes concentrações de ácido fosfórico (AF1%, AF10% e AF37%) na atividade proteolítica da dentina humana sadia, na degradação do colágeno exposto pela desmineralização, além de identificar imunologicamente as metaloproteinases. Material e Métodos: Vinte dentes molares permanentes foram triturados para obtenção de um pó de dentina. Alíquotas de 1g do pó foram acondicionadas em tubos plásticos para que a desmineralização do substrato pudesse ser realizada de acordo com as três diferentes concentrações de ácido fosfórico testadas. Após a neutralização do ácido com NaOH, as amostras foram centrifugadas. O sobrenadante foi utilizado para mensuração espectrofotométrica do conteúdo de Cálcio (Ca) liberado pela desmineralização. O precipitado obtido foi incubado com tampão de extração de proteínas por 24h a 4°C sob agitação. Nova centrifugação foi realizada e o sobrenadante utilizado para avaliação da atividade da MMP-2 e MMP-9 por zimografia e para a identificação imunológica das metaloproteinases por western blot. O precipitado obtido pela centrifugação foi liofilizado e separado em alíquotas de 40mg (n=10) de pó de dentina para cada condição experimental. As alíquotas foram incubadas em saliva artificial por 24h a 37°C sob agitação e hidrolisadas em autoclave. Após incubação a 65°C por 40 min, as amostras foram avaliadas por espectrofotometria para que a mensuração da concentração do aminoácido hidroxiprolina (HYP) liberado pela degradação do colágeno exposto pudesse ser obtida. Fatias de 0.3 mm da dentina coronária de outro dente foram obtidas e desmineralizadas, de acordo com as diferentes concentrações de ácido fosfórico para avaliação da atividade enzimática através do método da zimografia in situ. Os resultados foram submetidos à análise de variância de um fator sem vinculação ou teste de Kruskal-Wallis para identificação das diferenças existentes entre os grupos experimentais. Para contraste das médias foi realizado o teste de Student-Newman-Keuls com nível de significância de 5% (=0,05). Resultados: A atividade enzimática de MMP-2 foi estatisticamente maior quando a dentina foi desmineralizada com AF 1% ou 10%. O uso do ácido fosfórico 37% diminuiu consideravelmente a atividade desta enzima, em relação ao AF10% (<0,05). Em nenhuma das amostras desmineralizadas com AF foi detectada a atividade enzimática da MMP-9. A identidade da MMP-2 foi confirmada pelo immunoblotting da enzima com anticorpo específico. A MMP-9 não foi expressa nos extratos analisados. A expressão de MMP-2 foi maior quando utilizado AF 1% ou 10% e menor quando foi utilizado o AF 37%. A utilização do AF 37% liberou valores de Ca, em g/mL, estatisticamente superiores aos valores determinados para os demais grupos (<0,05). A maior concentração de HYP, em g/mL, foi encontrada nos extratos desmineralizados com AF 10%. Em seguida, aparecem os valores encontrados com o uso do AF1%. Os menores valores da concentração de HYP aparecem no grupo em que foi utilizado o AF 37% (<0,05). A concentração de HYP em função do peso de dentina utilizado (40mg) também foi calculada. A maior concentração de HYP por mg de dentina foi obtida com AF 10%, seguida pelos extratos desmineralizados com AF1%. Os menores valores foram detectados com AF 37% (<0,05). O uso do AF10% demonstrou ser responsável pela maior taxa de degradação de colágeno exposto (20,13%). Em seguida, aparecem valores intermediários (11,34%) obtidos com AF1%. Por último, surgem os menores valores (0,68%) com AF37%. A análise das imagens obtidas após a realização da zimografia in situ demonstrou maior atividade enzimática quando a dentina foi desmineralizada com AF10%. Conclusão: O uso do AF37% para o condicionamento da dentina durante a realização do procedimento adesivo pode minimizar os efeitos degradantes das proteases endógenas sobre o colágeno. Em contrapartida, estudos realizados com pó de dentina desmineralizado com AF1% ou 10% podem estar sobreestimando a atividade das MMPs, em relação à prática clínica. / The dentin adhesive interface degradation can occur in resin and in organic portion of the hybrid layer. Evidence indicates that the degradation of organic matrix may partially occur due to the enzymatic activity of proteases own dentin. The matrix metalloproteinases (MMPs) have been described as the first class of enzymes associated with degradation of the organic matrix. It is possible that MMPs may be reactivated during the adhesive procedure as a result of the fall of pH. Purpose: The objectives of the present investigation are to evaluate the influence of different demineralizing phosphoric acid solutions (PA1%, PA10% and PA37%) on the proteolytic activity of human sound dentin, on the collagen degradation that was exposed after demineralization, as well as to identify the metaloproteases immunologically. Material and Methods: Dentin powder was obtained from twenty human molars. One gram aliquots were placed in polyestyrene tubes and the dentin demineralization was performed using the three different phosphoric acid concentrations tested in this study. After neutralization with NaOH, the samples were centrifuged. The supernatant was used for the spectrophotometrically quantification of calcium (Ca) released by the demineralization while the precipitate was re-suspended and incubated with a protein extraction buffer for 24h at 4ºC under agitation. The sample was centrifuged and the supernatant was used for the identification of MMP-2 and MMP-9 by western blot and for the evaluation of gelatinolytic activity by zymography. The pellet was lyophilized and 40 mg aliquots of the dentin powder (n=10) were incubated in artificial saliva for 24h at 37°C under agitation and hydrolysed in autoclave after incubation at 65°C for 40 min. The samples were analyzed spectrophotometrically to measure the hydroxyproline (HYP) released after collagen degradation. Slices of 0.3 mm of the dentine crown of the another tooth were obtained and demineralized in accordance with the concentrations of phosphoric acid used in this study for evaluating the enzymatic activity by the method of in situ zymography.The data were analyzed by ANOVA one-way or Kruskal-Wallis test for the identification of differences between the experimental groups. The means were analyzed by Student-Newmans-Keulss test (=0,05). Results: The MMP-2 enzymatic activity was statistically higher when the dentin was demineralized with 1% or 10% PA. The 37% phosphoric acid decreased the activity of such enzyme relative to PA 10% (<0,05). MMP-9 activity was not detected in any demineralization condition (1%, 10% or 37% PA). MMP-2 identification was confirmed by immunoblotting while MMP-9 was not observed in any condition. MMP-2 identification was higher when 1% or 10% PA were used while 37% PA showed lower MMP-2 identification. The use of 37% PA resulted in higher release of Ca, which was significantly higher when compared to other PA concentrations (<0,05). The highest HYP concentration was observed when 10% PA was used, followed by 1% PA. The lowest values were observed for 37% PA (<0,05). The HYP concentration according to the dentin weight used (40 mg) was also calculated. Highest concentrations of HYP per mg of dentin were observed for 10% and 1% PA, while 37% PA resulted in the lowest HYP concentration (<0,05). The use of 10% PA showed to be responsible for the highest exposed collagen degradation after demineralization (20,13%) when compared to 1% PA (11,34%) and 37% PA (0,68%). The analysis of images obtained after the realization of in situ zymography showed greater enzyme activity when the dentin was demineralized in PA10%. Conclusion: The use of 37% PA for dentin etching during the restorative procedure might minimize collagen degradation by host-derived proteases. On the other hand, studies that have been using 1% or 10% PA might have overestimated MMPs activity when compared to the clinical situation.

The aim of this D.Phil was to develop a range of cyclisation cascades, which initially form a reactive iminium intermediates that can then be attacked by a pendant nucleophile resulting in novel polycyclic structures. This concept has been applied to the development of three methodologies and has resulted in the discovery of new reactivity as well as the synthesis of a wide range of interesting novel structures <b>Chapter 1: Enantioselective chiral-BINOL-phosphoric acid catalysed reaction cascade</b> A highly enantioselective hydroamination / N-sulfonyliminium cyclisation cascade using a combination of Au(I) and chiral phosphoric acid catalysts has been developed. Proceeding by an initial 5-exo-dig hydroamination and a subsequent phosphoric acid catalysed Pictet- Spengler cyclisation, the reaction provides access to complex sulfonamide scaffolds in excellent yields and with high levels of enantiocontrol. The scope can be extended to lactam derivatives, with excellent yields and enantiomeric excesses of up to 93&percnt; ee. <b>Chapter 2: Iridium catalysed nitro-Mannich cyclisation</b> A new chemoselective reductive nitro-Mannich cyclisation reaction sequence of nitroalkyltethered lactams has been developed. An initial rapid and chemoselective iridium(I) catalysed reduction of lactams to the corresponding enamine is subsequently followed by intra molecular nitro-Mannich cyclisation. This methodology provides direct access to important alkaloid, natural product-like structures in yields up to 81&percnt; and in diastereoselectivities that are typically good to excellent. An in-depth understanding of the reaction mechanism has been gained through NMR studies and characterisation of reaction intermediates. The new methodology has been applied to the total synthesis of (&plusmn;)-epi-epiquinamide in 4 steps. <b>Chapter 3: Iridium catalysed reductive interrupted Pictet-Spengler cyclisation</b> A novel reductive interrupted Pictet-Spengler cyclisation reaction cascade has been created. An iridium(I) catalyzed partial reduction of lactams/amides to the corresponding iminium is subsequently trapped by a pendant indole nucleophile. Interruption of the Pictet-Spengler reaction by indolium reduction provides a wide range of novel spirocyclic indoline moieties in excellent yield and diastereoselectivity.

Polymer electrolyte membrane fuel cells (PEMFCs) are one of the most promising clean technologies under development. However, the main obstacles for commercialising PEMFCs are largely attributed to the technical limitations and cost of current PEM materials such as Nafion. Novel poly(2,5-benzimidazole) (ABPBI)/POSS based polymer composite electrolyte membranes with excellent mechanical and conductivity properties were developed in this project including (I) ABPBI, polybenzimidazole (PBI) and their copolymers were synthesised by solution polymerisation and their chemical structures were confirmed by FTIR and elemental analysis. ABPBI/ActaAmmonium POSS (ABPBI/AM) and ABPBI/TriSilanolPhenyl POSS (ABPBI/SO) composites were also synthesised in situ. High quality polymer and composite membranes were fabricated by a direct cast method; and (II) The mechanical and thermal properties, microstructure and morphology, water and H3PO4 absorbility and proton conductivity of phosphoric acid doped and undoped ABPBI and ABPBI/POSS composite membranes were investigated. SEM/TEM micrographs showed that a uniform dispersion of POSS nano particles in ABPBI polymer matrix was achieved. The best performances on both mechanical properties and proton conductivities were obtained from the ABPBI/AM composite membrane with 3 wt% of POSS (ABPBI/3AM). It was found that both the water and H3PO4 uptakes were increased significantly with the addition of POSS due to formation of hydrogen bonds between the POSS and H2O/H3PO4, which played a critical role in the improvement of the conductivity of the composite membranes at temperatures over 100oC. ABPBI/3AM membranes with H3PO4 uptake above 117% showed best proton conductivities at both hydrous and anhydrous conditions from room temperature to 160oC, which is comparable with the conductivity of commercial Nafion 117 at 20oC in water-saturated condition, indicating that these composite membranes could be excellent candidates as a polymer electrolyte membrane for high temperature applications. A new mechanism for illustrating the improved proton conductivity of composite membranes was also developed.

<p>Nespu&scaron;teni testis predstavlja odsustvo testisa u skrotumu sa jedne ili obe strane. Faktori rizika za pojavu nespu&scaron;tenog testisa obuhvataju genetsku predispoziciju, prevremeno rođenje, nisku porođajnu masu i prenatalnu izloženost endokrinim disruptorima ili duvanskom dimu. Endokrini disruptori se defini&scaron;u kao egzogene supstance koje imaju uticaj na homeostazu organizma i proizvodnju reproduktivnih hormona. U ovoj grupi nalaze se organofosforni pesticidi koji se &scaron;iroko upotrebljavaju u poljoprivredi. Većina organofosfornih pesticida ima antiandrogeni uticaj i uz činjenicu da živimo u pretežno agrarnoj sredini predmet su na&scaron;eg interesovanja. Cilj istraživanja je da se utvrdi razlika u izloženosti organofosfornim pesticidima kori&scaron;ćenjem upitnika kreiranog po modelu standardizovanog Evropskog upitnika QLK 4-1999-01422 kod osoba koje su rodile zdravu mu&scaron;ku decu i osoba koje su rodile decu sa nespu&scaron;tenim testisom. Pored toga, cilj istraživanja je i da se odredi i uporedi vrednost metabolita organofosfornih pesticida (dimetilfosfat, dimetilditiofosfat, dietilfosfat, dietiltiofosfat i dietilditiofosfat) u urinu majki koje su rodile mu&scaron;ku decu sa nespu&scaron;tenim testisima i majki koje su rodile zdravu mu&scaron;ku decu. Metodologija: Rad je radomizovano, prospektivno, kliničko istraživanje sprovedeno na Klinici za ginekologiju i aku&scaron;erstvo Kliničkog centra Vojvodine i Katedri za farmakologiju i toksikologiju Medicinskog fakulteta, Univerziteta u Novom Sadu. U kliničko istraživanje uključeno je 50 porodilja koje su rodile mu&scaron;ku decu sa nespu&scaron;tenim testisima (eksperimentalna grupa) i 53 porodilje koje su rodile zdravu mu&scaron;ku decu (kontrolna grupa) u periodu od oktobra 2012. godine do aprila 2018. godine. Tokom boravka u porodili&scaron;tu ispitanice su popunjavale upitnik o navikama nakon čega im je uzet uzorak urina radi analiziranja nivoa metabolita OF pesticida. Uzorci urina su pripremljeni metodom koju su opisali Wu i saradnici 2010. godine, a potom analizirani na gasnom hromatografu masenom spektrofotometaru marke Agilent 7890A. Rezultati: Ispitivane grupe se ne razlikuju po starosti ispitanica (prosečna starost kontrolne grupe 29,41 &plusmn; 5,58 godina, a eksperimentalne 30,54 &plusmn; 4,87 godina). U obe grupe prosečno je ispitanicama ovo bila druga trudnoća. Ispitanice se nisu razlikovale ni po načinu porođaja. Prosečna gestacijska nedelja trudnoće na porođaju iznosila je 39,45 &plusmn; 1,38 nedelja za kontrolnu grupu i 39,20 &plusmn; 1,38 nedelja za eksperimentalnu grupu, a porođajna masa novorođenčeta 3527,30 &plusmn; 470,16 g u kontrolnoj grupi i 3404,37 &plusmn; 508,20 g u eksperimentalnoj grupi. Statistički značajna razlika postoji u odnosu na mesto stanovanja (50,9 % ispitanica kontrolne grupe i 77,6 % ispitanica eksperimentalne grupe žive u gradu), jedinicu stanovanja (67,9 % kontrolne i 45,7 % ispitanica eksperimentalne grupe žive u kući) i načinu začeća (6 % ispitanica eksperimentalne i 1,9 % ispitanica kontrolne grupe prijavilo je IVF kao način začeća). Skoro polovina ispitanica obe grupe su pu&scaron;ači, a njih 32,7 % kontrolne grupe i 38,8 % eksperimentalne pu&scaron;ile su i tokom trudnoće. Izloženost pesticidima prijavilo je 50,9 % ispitanica kontrolne i 44 % ispitanica eksperimentalne grupe, a profesionalnu izloženost prijavilo je 3 ispitanice kontrolne i 2 ispitanice eksperimentalne grupe. Ispitanice se ne razlikuju ni po poreklu voća i povrća koje konzumiraju, kao ni po vrsti voća koje su konzumirale tokom trudnoće. Prosečne izmerene vrednosti DMF u kontrolnoj grupi iznose 5,604 &plusmn; 6,103 ug/L, a u eksperimentalnoj 4,815 &plusmn; 6,729 ug/L. Izmerene vrednosti DEF u kontrolnoj grupi su 0,408 &plusmn; 0,447 ug/L, a u eksperimentalnoj 0,461 &plusmn; 0,593 ug/L. Nivo DMDTF u kontrolnoj grupi bio je 0,431 &plusmn; 0,508 ug/L, a u eksperimentalnoj 0,547 &plusmn; 0570 ug/L, a DETF 0,403 &plusmn; 0,606 ug/L u kontrolnoj i 0,529 &plusmn; 0,725 ug/L u eksperimentalnoj grupi. Ni jedan metabolit ne pokazuje statistički značajnu razliku u ispitivanim grupama. Slične vrednosti dobijene su i za vrednosti korigovane za nivo kreatinina. Univarijantna regresiona analiza pokazala je da ispitanice koje žive u gradu imaju 3,3 puta veće &scaron;anse da rode dete sa nespu&scaron;tenim testisom, a one koje žive u stanu imaju 2,5 puta veće &scaron;anse za isti ishod. Statistički značajna razlika primećena je u nivou DEDTF u zavisnosti od starosti ispitanica i jedinici stanovanja. Vi&scaron;e vrednosti DETF dobijene su kod ispitanica koje su bile na hormonskoj terapiji tokom trudnoće. Ispitanice koje su prijavile da su bile izložene pesticidima tokom trudnoće u urinu su imale statistički značajno vi&scaron;e vrednosti DMDTF u odnosu na ispitanice koje su se izjasnile da nisu bile izložene pesticidima. Slični rezultati za vrednost DEDTF dobijeni su kod ispitanica koje su se izjasnile da poseduju kućne ljubimce. Statistički vi&scaron;e vrednosti DEF i DETF korigovano za nivo kreatinina dobijene su kod ispitanica koje nisu konzumirale jabuke, a vi&scaron;e vrednosti DEF i DEDTF dobijene su kod ispitanica koje su konzumirale maline i kupine tokom trudnoće. Ostale grupe nisu pokazale statistički značajnu razliku među ispitivanim grupama. Zaključci: Izloženosti trudnica OF pesticidima nije značajno veća u grupi majki koje su rodile decu sa nespu&scaron;tenim testisom u odnosu na izloženost OF pesticidima kod majki zdrave mu&scaron;ke dece. Vrednosti metabolita OF pesticida (dimetilfosfat, dimetilditiofosfat, dietilfosfat, dietiltiofosfat, dietilditiofosfat) u urinu majki koje su rodile mu&scaron;ku decu sa nespu&scaron;tenim testisima nije vi&scaron;a u odnosu na vrednosti metabolita OF pesticida (dimetilfosfat, dimetilditiofosfat, dietilfosfat, dietiltiofosfat, dietilditiofosfat) izmerene u jutarnjem urinu majki koje su rodile zdravu mu&scaron;ku decu.</p> / <p>Undescended testis is the absence of testis in the scrotum on one or both sides. Risk factors for the occurrence of undescended testis include genetic predisposition, premature birth, low birth weight and prenatal exposure to endocrine disruptors or tobacco smoke. Endocrine disruptors are defined as exogenous substances that can affect homeostasis of the organism and the production of reproductive hormones. In this group are organophosphorus pesticides that are widely used in agriculture. Most of organophosphorus pesticides have anti-androgenic effect and with the fact that we live in a predominantly agricultural area, they are the focus of our interest. The aim of the research: The aim of this study is to determine the difference in exposure to organophosphorous pesticides using questionnaires created by standardized European model questionnaire QLK 4-1999-01422 in individuals who gave birth to a healthy male children and women who gave birth to children with undescended testis. In addition, the aim of this study is to determine and compare the value of metabolites of organophosphorus pesticides (dimethylphosphate, dimethyldithiophosphate, diethylphosphate, diethylthiophosphate and diethyldithiophosphate) in the urine of mothers who gave birth to male children with undescended testis and mothers who gave birth to healthy male children. Methodology: This work is randomized, prospective, clinical research conducted at the Clinic for gynaecology and obstetrics of the Clinical center of Vojvodina and the Department of Pharmacology and toxicology of the Faculty of Medicine, University of Novi Sad. This clinical research includes 50 new mothers that gave birth to male children with undescended testes (experimental group) and 53 new mothers that gave birth to healthy male children (control group) in the period from October 2012 to April 2018. During their stay at the maternity hospital the subjects were asked to fill out a questionnaire about habits and to give a urine sample for analyzing the level of metabolites of organophosphus pesticides. Urine samples were then prepared using the method described by Wu and associates 2010, and analyzed on gas chromatograph with a mass spectrophotometer Agilent 7890A brand. Results: Study groups do not differ according to the age of women (average age of control group is 29.41 &plusmn; 5.58 years, and experimental 30.54 &plusmn; 4.87 years). In both groups this was second pregnancy on average. The subjects did not distinguish either by the way of delivery. The average gestational weeks of pregnancy to childbirth was 39.45 &plusmn; 1.38 weeks for the control group and 39.20 &plusmn; 1.38 weeks for the experimental group, and birth weight of newborn was 3527.30 &plusmn; 470.16 g in control group and 3404.37 &plusmn; 508.20 g in the experimental group. There is no statistically significant difference in relation to the place of residence (50.9 % of the control group and 77.6 % of experimental live in the city), the living unit (67.9 % and 45.7 % of the control and experimental groups are living in the house) and the way of conception (6 % of experimental and 1.9 % of the control group reported IVF as a way of conception). Nearly half of both groups are smokers, and 32.7 % of women in the control group and 38.8 % in experimental smoked during pregnancy. Exposure to pesticides reported 50.9 % of mothers in control and 44 % of mothers in the experimental group. Professional exposure was reported by 3 control subjects and 2 subjects in experimental group. The subjects did not differ according to the origin of fruits and vegetables they were consuming, neither regarding the type of fruits they consumed during pregnancy. Average level of dimethylphosphate in control group was 5.604 &plusmn; 6.103 ug/L, and in experimental 4.815 &plusmn; 6.729 ug/l. Levels of diethylphosphate in control group were 0.408 &plusmn; 0.447 ug/L, and in experimental 0.461 &plusmn; 0.593 ug/l. DMDTP level in the control group was 0.431 &plusmn; 0.508 ug/L, and in experimental 0.547 &plusmn; 0570 ug/L, and the DETP was measured 0.403 &plusmn; 0.606 ug/L in control, and 0.725 &plusmn; 0.529 ug/L in the experimental group. These metabolites showed no statistically significant difference in the examined groups. Similar values are obtained for the adjusted values for creatinine level. Univariate regression analysis showed that the subjects who live in town are 3.3 times more likely to have child with undescended testis, and those who live in the apartment are 2.5 times more likely for the same outcome. Statistically significant difference was noticed in DEDTP level depending on the age of the subject and the living unit. Higher levels of DETP metabolites were detected in subjects that have been on hormonal therapy during pregnancy. The subjects who reported being exposed to pesticides during pregnancy had statistically significantly higher DMDTP values in relation to the subjects that were not exposed to pesticides. Similar results are obtained for the DEDTP level with higher levels in subjects owning pets. Statistically higher levels of DEP and DETP adjusted for creatinine were obtained in subjects that were not reporting eating apples, and higher levels of DEP and DEDTP were obtained in subjects that consumed raspberries and blackberries during pregnancy. Other groups showed no statistically significant difference between the study groups. Conclusion: Exposure of pregnant women to OP pesticides is not significantly greater in the group of mothers who gave birth to children with undescended testis in relation to exposure to OP pesticides in mothers of healthy male children. The level of OP metabolites (dimethylphosphate, dimethyldithiophosphate, diethylphosphate, diethylthiophosphate and diethyldithiophosphate) in the urine of mothers who gave birth to children with undescended testis is not higher in relation to the levels of OP metabolites (dimethylphosphate, dimethyldithiophosphate, diethylphosphate, diethylthiophosphate and diethyldithiophosphate) recorded in urine of mothers who gave birth to healthy male children.</p>

Ce projet scientifique porte sur le développement de nouvelles voies d’accès à des composés azotés hautement fonctionnalisés en s’adaptant aux principes de chimie verte. Tout d’abord, une réaction d’Ugi quatre composants à partir d’alcools a été étudiée. L’utilisation de dérivés de l’iode hypervalent comme oxydant en quantités stoechiométriques ou catalytiques a permis de réaliser un processus one-pot oxydation d’alcools/réaction d’Ugi efficace. Par la suite, une nouvelle réaction de Mannich quatre composants, réalisée en présence d’un acide phosphorique dérivé du BINOL, a permis l’accès à des 1,3-diamines énantiopures. La modification de l’électrophile imine par un composé de type diazène a ensuite mené à des précurseurs d’aminocétones ou d’1,2-diamines énantiopures par un procédé alliant catalyse, synthèse asymétrique et utilisation de composés non toxiques.Enfin, dans la continuité des travaux sur la réactivité des énamides, deux nouvelles réactions multicomposants catalysées au fer ont pu être développées. A partir d’énamides, d’un radical libre et de différents nucléophiles, plusieurs dérivés d’aminoalcools ont pu être synthétisés selon des processus propres et sélectifs. / The aim of this study is the development of new access to highly functionalized nitrogen-containing compounds with respect to the green chemistry principles.First, an Ugi four-component reaction from alcohols has been studied. In the presence of hypervalent iodine compounds, used as oxidant and introduced in stoechiometric or catalytic quantites, an efficient one-pot sequence has been developed.Then, a new four-component Mannich reaction using a catalytic amount of BINOL-derived phosphoric acid gave an access to enantioenriched 1,3-diamines from enamides. Changing the electrophilic imine partner to a diazene compound afforded aminoketones or 1,2-diamines precursors in high yields and excellent enantiomeric excess.Finally, two new iron-catalyzed multicomponent reactions of enamides with TEMPO and various nucleophiles provided an efficient synthesis of aminoalcohols derivatives. These domino reactions involving an oxidative process from enamides offered a convenient and economical method to establish two C-O bonds in a single operation.

Organophosphate (OP) poisoning is a health issue worldwide with over 200,000 deaths per year. Although not a problem in most developed countries, in some third world countries, one third of a hospital’s population could be patients with OP exposure. Even with the most aggressive therapy, 10-40% of patients admitted to an intensive care unit will die. Research into the best practice for treating OP poisoning is lacking, due somewhat to a lack of detailed understanding of the physiology of OP poisoning. Our research uses animal models of acute OP poisoning to explore the mechanism of OP-induced respiratory failure. Our research shows that animals poisoned with dichlorvos demonstrated a uniformly fatal central apnea that, if prevented, was followed immediately by a variable pulmonary dysfunction. Potential mechanisms for dichlorvos-induced central apnea can be divided into direct effects on the central respiratory oscillator (CRO) and feedback inhibition of the CRO. Two afferent pathways that can induce apnea include vagal feedback pathways and feed-forward pathways from the cerebral hemispheres. In our studies we found that vagal feedback and feed forward inhibition from the cerebral hemispheres were not required for OP-induced central apnea. The pre-Botzinger complex in the brainstem is thought to be the kernel of the CRO, but exposure of the pre-Botzinger complex to dichlorvos was not sufficient for apnea. Although OP induced central apnea was uniformly fatal, partial recovery of the CRO occurred post apnea with mechanical ventilation. Central apnea was ubiquitous in our rat poisoning model, but pulmonary dysfunction was extremely variable, with a range of pulmonary effects from fulminate pulmonary failure with prominent pulmonary secretions to no pulmonary dysfunction at all. Vagal efferent activity is involved in neural control of pulmonary tissue but the vagus was not involved in OP-induced pulmonary dysfunction. Anti-muscarinic medications are the mainstay of clinical therapy and are commonly dosed by their effects on pulmonary secretions. Our studies found that atropine (the most common therapeutic agent for OP poisoning) resulted in a ventilation-perfusion mismatch secondary to effects on the pulmonary vasculature.

Le développement de méthodes de synthèse asymétrique est très important pour l’accès à des molécules à visées thérapeutiques. Dans ce contexte, nous nous sommes intéressés à l’utilisation d’organocatalyseurs chiraux pour la synthèse de molécules cycliques énantioenrichies. Dans une première partie sont présentées des réactions de cycloadditions formelles (3+2), (4+2) et (4+3) à partir d’ènecarbamates ou de diènecarbamates catalysées par des acides phosphoriques chiraux. Ces derniers étant bifonctionnel, ils permettent l’activation des deux partenaires de cycloaddition menant à la synthèse d’indolines, de 2,3-dihydrobenzofuranes, de benzoquinones carbonannulées, de cyclohepta[b]indoles et de tétrahydroquinolines de façon hautement stéréosélective. Dans une seconde partie, nous nous sommes intéressés à l’utilisation de composés d’iode hypervalent chiraux comme organocatalyseurs. En effet, ces composés présentent une réactivité intéressante tout en étant stable et faiblement toxique. Ainsi, leur utilisation dans une réaction de lactonisation à partir de substrats flexibles a permis l’obtention de divers hétérocycles avec de bons résultats. / The development of new enantioselective methodologies is essential for the synthesis of bioactive compounds. In this context, we were interested in using organocatalysts for the synthesis of enantioenriched cyclic molecules. In a first part will be describe chiral phosphoric acid catalyzed (3+2), (4+2) and (4+3) formal cycloadditions using enecarbamate or dienecarbamate. These catalysts are bifunctional and can interact with both cycloaddition partners leading to the synthesis of 2,3-dihydrobenzofuranes, carboannulated benzoquinones, cyclohepta[b]indoles and tetrahydroquinolines with high stereocontrol. In a second phase, we were interested in using chiral hypervalent iodine as organocatalyst. Theses compounds present interesting reactivity while being stable and not very toxic. Their use permits us to develop a lactonisation starting from flexible substrate and led to the synthesis of various heterocycles with good results.