Para avaliar a confiabilidade à fadiga de coroas de dissilicato de lítio E.max CAD, com 1mm (monolítica) e 2mm de espessura, foi realizado um preparo para coroa total de um primeiro molar inferior com redução de 1 e 2mm. Réplicas em resina composta do preparo baseado em desenho auxiliado pelo computador (CAD) foram posicionadas em um articulador odontológico para fabricação dos corpos de prova. As coroas monolíticas de 1mm de dissilicato de lítio CAD/CAM (DLM) e coroas de 2.0mm, com 1,5mm de espessura vestibular de dissilicato de lítio CAD/CAM e recoberta com 0.5mm de porcelana (DLV), foram comparadas com coroas de zircônia (Y-TZP) e metalocerâmica (MC). As réplicas de resina composta foram envelhecidas em água por 30 dias e todas coroas cimentadas com cimento resinoso. Após cimentadas, todos os corpos de prova foram envelhecidos em água por 7 dias e testados com carga única ou com fadiga acelerada progressiva. As cargas foram posicionadas na cúspide mésiovestibular (n=21 para cada sistema cerâmico). A probabilidade Weibull e os gráficos de probabilidade (Alta Pro, Reliasoft) foram calculados (Best data fit QCP) e plotados. A evolução da trinca foi acompanhada e os espécimes analisados após o teste. A menor confiabilidade foi observada para o grupo Y-TZP e não houve diferença estatística entre o grupo MC, DLM e DLV. O grupo DLV demonstrou a maior resistência característica (Eta). O modo de fratura do grupo Y-TZP foi a fratura da porcelana de cobertura sem exposição da infraestrutura. O grupo MC apresentou fraturas da porcelana com exposição do metal. Enquanto os grupos DLM e DLV tiveram fraturas catastróficas. Os grupos DLM e DLV apresentaram uma resposta à fadiga semelhante à do grupo MC e melhor que o grupo Y-TZP. / To evaluate the fatigue reliability of monolithic 1mm and thinly veneered 2mm E.max CAD crowns. A preparation reduction of 1 and 2mm for a full crown was made on a first lower molar. The CAD-based preparation was replicated and positioned in a dental articulator for specimen fabrication. Monolithic 1mm lithium disilicate CAD/CAM crowns (DLM) and a 2mm lithium disilicate CAD/CAM with 1.5 mm thick at buccal aspect veneered with 0.5 mm thick of porcelain were compared to zirconia based (Y-TZP) and metaloceramic (MC) crowns. All composite dies were 30-day aged and all crowns were resin cemented to composite dies. After luting, all specimens were aged for 7 days in water and either single loaded to failure or step-stress fatigue tested. Loads were positioned on mesial-buccal cusp (n=21 for each ceramic system). Probability Weibull and Use level probability curves (Alta Pro, Reliasoft) were calculated (Best data fit QCP) and plotted. Crack evolution was followed and specimens were analyzed postmortem. Lower reliability was observed for Y-TZP group and no statistical difference was observed between MC and DLM e DLV groups. DLV group showed the highest characteristic strength (Eta). Fracture mode for Y-TZP group was veneer chipping without core exposition. MC fractures were mostly chipping with metal coping exposure. While the failure for DLM and DLV groups were bulk fracture. Groups DLM and DLV resulted in fatigue response of lithium disilicate comparable to MC and higher than Y-TZP.

As cerâmicas à base de dissilicato de lítio apresentam propriedades mecânicas, resistência química, biocompatibilidade, baixo índice de acúmulo de placa e resultados estéticos favoráveis. Entretanto, sua resistência à fadiga e probabilidade de sobrevida (confiabilidade) em sua forma estratificada e monolítica ainda é pouco conhecida. Este estudo tem como objetivo investigar a confiabilidade e o modo de falha das coroas estratificadas de dissilicato de lítio com e sem modificação do desenho da infraestrutura e de coroas monolíticas quando submetidas ao ensaio de fadiga por intermédio da ciclagem dinâmica em água. Trinta coroas foram divididas em 3 grupos: IEC (coroas estratificadas com infraestrutura convencional), IEM (coroas estratificadas com infraestrutura modificada) e MON (coroas monolíticas). Para os grupos IEC e IEM as infraestruturas apresentavam espessura de 0,8 mm. No entanto, no desenho modificado era adicionado uma cinta lingual de 2 mm de altura conectada a postes proximais de 3,5 mm de altura, ambos com 1,3 mm de espessura. As MON eram compostas inteiramente de dissilicato de lítio e apresentavam espessura oclusal de 1,5 mm. As coroas foram cimentadas em troqueis de resina composta e submetidas a ciclagem dinâmica em água (30-300 N). Um endentador monolítico de dissilicato de lítio aplicava carga axial sobre a crista marginal mesial até a fratura, e posteriormente na crista distal. Ao final, as coroas eram analisadas em estereomicroscópio e no microscópico eletrônica de varredura (MEV) para caracterização e classificação dos danos. As falhas encontradas nas coroas foram registradas a cada 125.000 ciclos. A distribuição Weibull a 2 parâmetros (Synthesis 9, Weibull ++; Reliasoft, Tucson, AZ, USA) foi utilizada para calculo da probabilidade de sobrevida em 1, 2 e 3 milhões de ciclos. Comparações entre os grupos também foram realizadas com o módulo de Weibull e a resistência característica (número de ciclos decorrido até a fratura). Tanto em 1 quanto em 2 milhões de ciclos, a probabilidade de sobrevida foi significativamente baixa para as IEM em relação as MON e as coroas IEC não apresentaram diferença entre as IEM e MON. Em 3 milhões, apenas as coroas monolíticas mantiveram a confiabilidade, considerandoque diminuiu significativamente para as estratificadas, independente da modificação da infraestrutura. Fraturas envolvendo os postes proximais e/ou a cinta lingual foram observadas para as IEM, enquanto as IEC o modo de falha predominante foi a fratura coesiva da porcelana de revestimento. As MON também apresentaram fraturas coesivas. As marcas fractográficas identificaram a superfície de contato com o endentador como origem das fraturas. Em conclusão, a alta confiabilidade foi observada para as coroas MON em 3 milhões. As coroas estratificadas não se beneficiaram da modificação das infraestrutura, pois não houve diferença na confiabilidade entre elas nos 3 tempos avaliados. Além disso, o modo de falha no grupo IEM não restringiu a fratura coesiva da porcelana, com presença de fraturas na infraestrutura. Falhas coesivas foram observadas apenas na porcelana de revestimento das IEC e na cerâmica no grupo MON. / Lithium disilicate glass-ceramic provides desirable mechanical properties, chemical resistance, biocompatibility, diminished plaque accumulation, esthetics, and favorable esthetic results. However, the fatigue life and probability of survival (reliability) of lithium disilicate in its monolithic or layered form is still poorly understood. This study aimed to investigate the reliability and failure modes of porcelain veneered lithium disilicate crowns with and without core design modification, and of monolithic crowns when subjected to cyclic fatigue in water. Thirty lithium disilicate molars crowns were made and divided into 3 groups: IEC (bilayer crown with even thickness coping, i.e. conventional core), IEM (bilayer crowns with modified core design) and MON (monolithic crowns). For groups IEC and IEM, copings presented an even thickness of 0.8 mm and the modified design consisted of 1.3 mm thickness with a lingual margin of 2.0mm height connected to full contour proximal struts of 3.5 mm height. Monolithic crowns had an occlusal thickness of 1.5 mm. Crows were luted on composite resin abutment replicas and subjected to cyclic fatigue in water (30-300 N). A monolithic indenter of lithium disilicate was used to deliver the load on the mesial marginal ridge until failure, then the same procedure was performed in the distal ridge. For failure characterization crowns were analyzed in stereomicroscope and scanning electron microscope (SEM). Failure inspection was performed every 125,000 cycles. The 2-parameter Weibull distribution (Synthesis 9, Weibull ++; Reliasoft, Tucson, AZ, USA) was used calculate the probability of survival at 1, 2, and 3 million cycles. Comparisons between groups were also made for Weibull modulus and characteristic strength (number of cycles elapsed until failure). At both 1 and 2 million cycles, reliability was significantly lower for IEM relative to MON and IEC showed no difference between the IEM and MON. At 3 million cycles, only monolithic crowns maintained the reliability, whereas it significantly decreased for porcelain veneered crowns, regardless of core design modification. Fractures involving the proximal struts and/or lingual collar were observed for IEM crowns, whereas IEC crowns chiefly presented porcelain cohesive failures. MON crowns fractured cohesively. All fractures started occlusaly, as depicted by telltale fratographic marks. In conclusion, the highest reliability was observed for MON crowns at 3 million cycles. Layered lithium disilicate crowns did not benefit from framework design modification, as there was no difference in reliability between them in 3 times evaluated. Also, failure modes differed between groups and IEM did not hinder porcelain cohesive failures, instead fractures involving the framework were observed. Cohesive failures were observed only for the porcelain veneer of IEC, and of the lithium dissilicate material in the MON group.

Abstract The aim of this study was to examine the effect of preterm birth on the development of the dentition. The spesific aims were to examine the effect on deciduous and permanent tooth crown dimensions, the eruption of permanent teeth and the sagittal occlusal relationships within the dentition. The subjects consisted of 328 prematurely born (< 37 gestational weeks ) white and black children and 1804 control children, who participated in the cross-sectional study of the Collaborative Perinatal Project (USA) in the 1960's and 1970's. Dental examinations, including dental casts were performed at the age of 6–12 years. Tooth crown size measurements, recording of the sagittal occlusal relationships and tooth eruption stages were performed by examining the dental casts. In general larger permanent tooth crown dimensions were found in preterm white boys and black girls and smaller permanent tooth crown dimensions in preterm white girls and black boys. There were both increased and decreased deciduous tooth crown dimensions in preterm children compared to controls, but no significant differences were found. Boys had larger tooth crown sizes than girls within all preterm and control groups showing sexual dimorphism. The results showed earlier eruption of permanent incisors and first molars in all preterm children compared to controls and also according to sex and race. Concerning the sagittal occlusal relationships, the results showed greater prevalence of prenormal canine relationships in preterm group than in the controls. When the molar relationships were concerned, the prevalence of mesial molar occlusion was greater in the preterm group. The incidence of bilateral symmetrical canine relationship was the same in both preterm and control groups, but inside the preterm group the girls had better symmetry than the boys. The findings of this research suggest that short gestation is not associated with reduced permanent and deciduous tooth crown dimensions in prematurely born children and also confirm the presence of the sexual dimorphism in tooth crown size. The studies also indicate that the clinical tooth eruption is accelerated in all observable permanent teeth in prematurely born children. The findings of occlusal morphology indicated that premature birth may effect the sagittal occlusal development. General health condition, neonatal and postnatal factors like intubation, postnatal molding of head shape and the importance of catch-up growth and early functional activity should be considered as possible influencing factors. Preterm birth may also interfere with the development of symmetry and lateralization.

D.Phil. (Chemistry) / The problem of maintaining good quality of water for domestic use and for aquatic life remains a challenge. Water sources are often contaminated with pollutants from natural sources such as volcanic eruptions and by human activities such as manufacturing industries, mining, water-purification processes, agricultural activities and a vast number of other activities. Water-purification processes used by municipal authorities are designed to remove most of the pollutants but some trace amounts will always remain and have been detected in drinking water and treated waste water reservoirs. These trace amounts pose a threat to human health and the well-being of aquatic life. The detection of these trace amounts of pollutants is often carried out by laboratory-based techniques that require sophisticated, expensive instruments and often require extensive sample preparation and pre-concentration. Simple, quick and in-field detection methods are necessary especially for remote small communities with limited or no access to laboratories. Optical detection systems offer hope as a solution to this problem. In this work newly developed fluorescence-based molecular sensors for the detection of pollutants in water were developed, characterised and tested for their sensing abilities towards organic and inorganic pollutants. The fluorescent probes for organic pollutants were designed based on the host-guest chemistry of the cyclodextrin molecule. Azo dye-modified β-cyclodextrins were synthesised and linked via ethylene glycol and epichlorohydrin to produce the sensors that were then tested for their sensing response towards chlorophenols and small aliphatic chlorinated alkanes which are often formed during the disinfection of water in the purification process. The sensor molecules were characterised by UV-Vis, FT-IR and 1D and 2D NMR spectroscopy. The amount of cyclodextrin in each sensor molecule was quantified using the anthrone method (67%) as well as by 1H-NMR spectroscopy (72%). To demonstrate the host-guest interaction of the sensor molecules, isothermal titration calorimetry (ITC) was used. ITC measurements showed that modifying β-cyclodextrin and using linkers did not alter its host-guest interaction with guest molecules as demonstrated by the stoichiometry, n, stability (or binding or association) constant (K) and thermodynamic parameters of the interaction. The sensor molecule linked via ethylene glycol showed selectivity towards 4- chlorophenol among the chlorophenols investigated and has the potential to be used in a sensor for the detection of 4-chlorophenol. The sensor molecule linked via epichlorohydrin showed sensitivity towards chloroform, a typical disinfection by-product. These experimental results showed that the sensor molecules could be used for quick on-field detection of chlorinated organic compounds in water. Sensor molecules for inorganic pollutants were based on the complex formation of crown ethers with metal ions. The sensor was formed by modifying a dibenzo-18- crown-6 ether molecule with an azo dye. The sensor was then characterised using UV-Vis spectrophotmetry, FT-IR and NMR spectroscopies as well as mass spectrometry and CHNS elemental analysis. The sensor molecule was then subjected to different metal ions and the fluorescence change of the probe observed. Interestingly, the sensor was highly sensitive and selective to mercury (II) and Cu (II) ions in water. Mercury (II) is one of the most hazardous heavy metals among the heavy-metal ions found in environmental waters and its early detection in water sources is important. The synthesised molecular sensor can therefore be incorporated into a simple hand-held gadget with a light source and be used for on-field detection of mercury (II) ions in remote areas.

A symbiotic association between leguminous roots and soil fixing nitrogen bacteria is required for legume nodule formation. The primary function of nodules is the fixation of nitrogen from the atmosphere into an accessible form for plants. In this study, nodules of plants of the soybean cultivar Prima 2000 were characterized and their number and weight were determined during nodule development. Their nitrogen-fixing activity during nodule development was determined by color evaluation. A pink nodule color showed active leghemoglobin required for nitrogen fixation and a green nodule color nonfunctional leghemoglobin. Strong appearance of nonfunctional leghemoglobin in the later stages of nodule development during senescence was accompanied by an increase in protease activity within crown nodules demonstrated by gelatine-containing SDS PAGE. Cysteine protease activity was identified as a major protease activity during nodule senescence when the cysteine protease inhibitor E-64 was used to block total protease activity. Products, which may indicate the expression of cysteine protease inhibitors during nodule development, were detected with the reverse zymogram technique and Western blotting. However, these bands have not been characterized so far in more detail. Putative transgenic plants were produced using the Agrobacterium transformation technique to allow determining the activity of native and mutated papaya cysteine protease inhibitor coding sequences. These sequences will ultimately be used for soybean transformation to reduce cysteine protease activity in nodules. However, the presence of coding sequence in the genome of these putative transgenic plants could not be confirmed by gene amplification and protease activity testing. Overall, this study has contributed to establish parameters to measure nodule growth and performance during development. / Dissertation (MSc)--University of Pretoria, 2010. / Plant Science / unrestricted

In this paper. I analyze how political, economic, and administrative issues were major factors in the BC Liberal government's creation of a complex hybrid operating structure for BC Ferries. The model evolved as the result of a number of circumstances, including the former NDP government's "fast ferry" debacle and the Liberal government's decision to conduct a Core Services Review of all government services, including those provided by Crown corporations. BC Ferries' new structure has similarities to other administrative models that have been introduced as a result of New Public Management initiatives and other factors in a number of Westminster jurisdictions. The resulting operating entities are having significant impacts on the nature and scope of public accountabilities and on reporting structures. / Arts, Faculty of / Political Science, Department of / Graduate

Previous work in our group has been directed towards the synthesis of crown-ethers for use in the selective complexation of metal ions and as chiral ligands for use in asymmetric catalysis. The development of a modular approach to macrocycle assembly has enabled the synthesis of a library of pyridine-based macrocycles possessing multiple donor sites where chirality was readily introduced from simple amino acids.The nucleophilic ring opening of aziridines 181, 193 or 194, allowed the highly selective synthesis of thioether-based spacers and macrocycles. Extension of this basic approach to the synthesis of seleno-crown ethers was also investigated. The use of chiral-pool starting materials derived from D- or L-alanine, provided access to optically pure macrocycles. The use of the Sharpless-Huisgen 'click' reactions allowed the attachment of a carbohydrate residue directly to a macrocycle via a triazole unit. We hope to attach a macrocycle, carbohydrate residue and azo dye together, to be able to examine further diseases such as Alzheimer's. We have so far succeeded in attaching a macrocycle and sugar to a central scaffold by performing a one-pot double 'click' reaction. The distance between the points of attachment of the chromophore to the macrocycle metal binding site is probably, in this first generation sensor, too great to enable a metal-macrocycle binding event to be reported.

The Crown has extensive powers and can sometimes cause injuries to those it governs through the use or misuse or these powers. Since there is no legislative scheme in place in Québec to create a specific regime for compensating these injured parties, the Crown is generally subject to the law of the land just like any other subject of the law. The separation of powers in Canada limits the power of the courts to review and evaluate Crown actions. The deference they must exercise in this review ensures that courts do not encroach on the legislative’s will to endow the Crown with its sovereign powers. This deference is relatively well understood in public law when it comes to declaring whether the use of these sovereign powers by the Crown was legal and within its mandate. The same principle of deference also applies to civil lawsuits in compensation. In Québec, the current form this deference takes is that the Crown is immune from normal rules of civil liability when it uses its core policy powers (such as regulatory powers), unless these powers were exercised in bad faith. This judicial scheme, however, appears unnecessary and needlessly complex. The definition of bad faith has been construed by the Supreme Court to include any action that would constitute a gross fault under the Québec civil law regime; in practice, the exercise of policy powers would command deference even if the standard was that of a simple fault. This means that the immunity only protects the Crown from injuries caused by the sort of action that it would not be liable for under the private law regime, making the immunity unnecessary.

COOPERATING DEFENDANT Abstract The aim of the thesis is to present and analyse the current legislation of the cooperating defendant in the Czech Republic. The thesis is divided into 6 chapters. The first part is focused on defining the terms crown witness and cooperating defendant. In the second chapter, the author deals with organized crime, because the main purpose of the institute of a cooperating defendant is to combat this phenomenon. The third chapter describes the current legal regulation of the institute of a cooperating defendant. The changes made by Act No. 333/2020 Sb. with effect from 1st October 2020 are also mentioned. The last part of this chapter is devoted to the issue of protection of a cooperating defendant in the Czech legal system. In the fourth chapter, the problematic points of the current legislation are highlighted and are followed by the de lege ferenda considerations. The fifth chapter deals with available data regarding the use of the institute of cooperating defendant in practice, i.e. specifically the frequency of use of this institute, in which crimes it occurs the most and what punishments are imposed on cooperating defendants. In the last chapter, the author deals with the institute of a cooperating defendant in the Italian legal system. It describes the legislation of the...

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