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This thesis presents the use of Computer Numerically Controlled (CNC) machining as a method to manufacture anatomically-shaped synthetic grafts made from Calcium Polyphosphate (CPP) ceramic. Tissue-engineered cartilage is grown on the surface of these implants in vitro followed by in vivo implantation in the host’s body for osteochondral focal defect repair. While most current implants are manufactured from simple geometries and are not specific to one patient’s need, it is believed that custom manufactured implants (from computer tomography data) representing the exact shape of the original bone will be beneficial. This is because custom implants permit an even stress distribution on the cartilage, resulting in increased cartilage survival rates. The present study has successfully manufactured and delivered a custom designed implant with sufficient surface porosity and minimal chipping. This was accomplished by effectively modeling the machinability characteristics and finding the optimal cutting conditions for CPP. CPP’s machinability characteristics were investigated and a cutting force prediction model was developed. This model was verified by a comparison of experimental and predicted forces for a number of ball and flat endmilling tests. The optimal cutting conditions that would result in maximum surface porosity and minimal chipping were established through qualitative investigation of results from varied conditions using Scanning Electron Microscope (SEM) images. Using the established optimal cutting conditions from machinability studies, the multi-axis machining process for producing the designed custom implant was developed and all stages were simulated for accuracy and integrity of the final implant. The designed toolpaths were tested on prototyping wax and verified against the actual Computer Aided Design (CAD) model using an optical microscope. The same toolpaths were executed on a block of CPP and the final implant was again investigated for surface porosity and chipping. After final comparison against the CAD model using an optical microscope, the implant was delivered to surgeons for implantation.

This thesis presents the use of Computer Numerically Controlled (CNC) machining as a method to manufacture anatomically-shaped synthetic grafts made from Calcium Polyphosphate (CPP) ceramic. Tissue-engineered cartilage is grown on the surface of these implants in vitro followed by in vivo implantation in the host’s body for osteochondral focal defect repair. While most current implants are manufactured from simple geometries and are not specific to one patient’s need, it is believed that custom manufactured implants (from computer tomography data) representing the exact shape of the original bone will be beneficial. This is because custom implants permit an even stress distribution on the cartilage, resulting in increased cartilage survival rates. The present study has successfully manufactured and delivered a custom designed implant with sufficient surface porosity and minimal chipping. This was accomplished by effectively modeling the machinability characteristics and finding the optimal cutting conditions for CPP. CPP’s machinability characteristics were investigated and a cutting force prediction model was developed. This model was verified by a comparison of experimental and predicted forces for a number of ball and flat endmilling tests. The optimal cutting conditions that would result in maximum surface porosity and minimal chipping were established through qualitative investigation of results from varied conditions using Scanning Electron Microscope (SEM) images. Using the established optimal cutting conditions from machinability studies, the multi-axis machining process for producing the designed custom implant was developed and all stages were simulated for accuracy and integrity of the final implant. The designed toolpaths were tested on prototyping wax and verified against the actual Computer Aided Design (CAD) model using an optical microscope. The same toolpaths were executed on a block of CPP and the final implant was again investigated for surface porosity and chipping. After final comparison against the CAD model using an optical microscope, the implant was delivered to surgeons for implantation.

<p>During the last few years, Ericsson has developed an emulator for the telephone system called CPP (Connectivity Packet Platform) with TietoEnator as a subcontractor. The emulator is called CPPemu and emulates the hardware used in the network nodes in CPP. This means that the same software that may be run on a node in a CPP network may be run on the emulated hardware in the emulator. TietoEnator would like to examine whether the emulator may be used for testing software instead of running tests using physical hardware. For this experiment, a particular event will be tested in the CPP emulator.</p><p>A fail-over procedure, which works in a physical CPP node, will be verified to work in the CPP emulator. A fail-over may be defined as</p><p>The failure and automatic replacement of part of a system such that the user does not notice the failure and is not affected by it. The part which has failed is replaced by a backup part.</p><p>This experiment consisted of three majors steps, namely (i) configuring the emulator, (ii) creating a network by setting up a redundant network (one main link and one backup link) between two emulated nodes and finally (iii) testing the fail-over procedure. The fail-over was tested by generating and sending traffic through the network, triggering the fail-over by ejecting the board which is currently sending and receiving traffic and inspecting the log files to evaluate if the fail-over works as intended. The results of the experiment indicated that the system performed as expected.</p>

During the last few years, Ericsson has developed an emulator for the telephone system called CPP (Connectivity Packet Platform) with TietoEnator as a subcontractor. The emulator is called CPPemu and emulates the hardware used in the network nodes in CPP. This means that the same software that may be run on a node in a CPP network may be run on the emulated hardware in the emulator. TietoEnator would like to examine whether the emulator may be used for testing software instead of running tests using physical hardware. For this experiment, a particular event will be tested in the CPP emulator. A fail-over procedure, which works in a physical CPP node, will be verified to work in the CPP emulator. A fail-over may be defined as The failure and automatic replacement of part of a system such that the user does not notice the failure and is not affected by it. The part which has failed is replaced by a backup part. This experiment consisted of three majors steps, namely (i) configuring the emulator, (ii) creating a network by setting up a redundant network (one main link and one backup link) between two emulated nodes and finally (iii) testing the fail-over procedure. The fail-over was tested by generating and sending traffic through the network, triggering the fail-over by ejecting the board which is currently sending and receiving traffic and inspecting the log files to evaluate if the fail-over works as intended. The results of the experiment indicated that the system performed as expected.

The rewarding properties of drugs in the mammalian system depend on their ability to activate appetitive motivational states. The associated underlying mechanism is strongly conserved in evolution and invertebrates have recently emerged as a powerful new model in addiction research. The natural reward system in crayfish has surprisingly proven sensitive to human drugs of abuse, providing a new model for research into the basic biological mechanisms of drug addiction. In this study, we examined the presence of natural reward systems in crayfish, and then characterized its sensitivity to 2.5 μg/g, 5.0 μg/g and 10.0 μg/g doses of methamphetamine (METH). Using the conditioned place preference (CPP) paradigm, we demonstrated that irrespective of the number of doses of METH injected into the pericardial system, crayfish seek out a particular tactile environment that had previously been paired with the METH. This study demonstrates that crayfish offer a comparative and complementary approach in addiction research. It contributes an evolutionary context to our understanding of a key component in learning and of natural reward as an important life-sustaining process.

O objetivo do presente estudo foi avaliar o efeito da associação do laser de diodo ao CPP-ACP ou verniz fluoretado na resistência a desmineralização do esmalte dentário. Foram utilizados 90 fragmentos de terceiros molares humanos irrompidos, selecionados por microdureza superficial e isolados com resina composta deixando apenas uma área de 4x4mm exposta. Em seguida foram desmineralizados por 32 h e 60 espécimes tiveram metade da área (2x4mm) isolada. Os espécimes foram divididos aleatoriamente em seis grupos/subgrupos, de acordo com os tratamentos propostos: G1-Controle (sem tratamento); G2- CPP-ACP, G3-verniz fluoretado Duraphat®; A - sem laser, B- tratamento com laser de diodo (0,7W, 70mJ, 10Hz). Na sequência foi realizado ciclo de pH para indução de desmineralização por oito dias. A solução desmineralizante de cada espécime foi armazenada para análise do cálcio por espectrometria de absorção atômica (n=10). Os espécimes foram seccionados ao meio, uma das metades foi analisada por microdureza longitudinal (n=10) e a outra por rugosidade (n=10) e morfologia superficial (n=10). Para a análise por Tomografia de Coerência Óptica (OCT) foi empregado n=5 por grupo/subgrupo e realizou-se a OCT em 2 fases, sendo a primeira após a desmineralização por 32h e a segunda após os tratamento/ciclagem de pH. Para a microdureza empregou-se a variação percentual da dureza, para a espectrometria de absorção atômica empregou-se a quantidade total de cálcio perdido, para a rugosidade superficial e OCT empregou-se a diferença entre os valores da desmineralização inicial e os valores obtidos após a ciclagem. Os dados foram analisados pelo método não paramétrico de Kruskal-Wallis e o teste de Dunn para diferenciação das médias (&prop;= 5%). Pode-se observar que ocorreu maior perda de dureza, de cálcio e maior profundidade de desmineralização nos grupos controle quando comparados com os grupos que receberam os tratamentos (G1A&asymp;G1B e &ne; G2A&asymp;G2B&asymp;G3A&asymp;G3B) sendo estatisticamente diferente (p<0,05). Maior rugosidade foi encontrada nos grupos G1A, G1B e G3A e foi estatisticamente significante (p<0,05). O fator laser não influenciou nas propriedades analisadas. Na microscopia confocal a laser não foram observadas áreas de fusão ou qualquer alteração na estrutura do esmalte irradiado. Pode-se concluir que o laser associado à CPP-ACP ou verniz fluoretado não foi capaz de aumentar a resistência ácida do esmalte submetido a ciclos de pH. Os tratamentos, MI Paste e verniz fluoretado foram eficazes independente da utilização do laser. / The aim of this study was to assess the effect of diode laser in combination with CPP-ACP/ fluoride varnish on enamel resistance to demineralization. Ninety fragments of unerupted human 3rd molar teeth were selected according to superficial microhardness and covered with compound resin, with only a 4x4mm area left exposed. They were then demineralized for 32 hours and 60 specimens had their exposed area halved. The specimens were randomly divided into 6 groups/subgroups, in line with the proposed treatments: G1-Control (no treatment); G2- MI Paste®, G3- fluoride varnish Duraphat® 5%; A - no laser, B- treatment with diode laser (0.7W, 70mJ, 10Hz). Afterwards, an 8-day pH cycle was carried out to induce demineralization. The demineralizing solution for each specimen was stored for the purpose of atomic absorption spectometry for the determination of calcium (n=10). The specimens were cut in half. The first half was analyzed using the criterium of longitudinal microhardnesss (n=10), the second the criterium of roughness (n=10) and superficial morphology (n=10). Optical coherence tomography (OCT) was used to assess group/subgroup for n=5. OCT was carried out at 2 moments, after a 32-hour demineralization period and post pH treatment/cycling. For microhardness we used percent change in hardness, for atomic absorption spectrometry the total amount of calcium lost, for superficial hardness and OCT the difference between the figures seen after initial demineralization and those obtained post cycling. The data were analyzed using the nonparametric Kruskal-Wallis Multiple-Comparison Z-Value Test and the Dunn test for distinguishing mean values (&prop;= 5%). Greater loss of hardness, greater loss of calcium, and deeper demineralization were seen in the control groups, when compared to those groups that underwent treatment (G1A&asymp;G1B and &ne; G2A&asymp;G2B&asymp;G3A&asymp;G3B). Greater roughness was found in groups G1A, G1B, and G3A, and it was statistically significant (p<0.05). Overall, laser use did not exert influence upon the analyzed properties. Confocal laser scanning microscopy did not reveal areas of fusion or any alteration in the structure of irradiated enamel. One can conclude that associating laser to CPP-ACP or fluoride varnish did not increase enamel resistance to acid when it underwent pH cycles. The treatments, MI Paste, and fluoride varnish were effective, regardless of the use of laser.

O objetivo do presente estudo foi avaliar o efeito da associação do laser de diodo ao CPP-ACP ou verniz fluoretado na resistência a desmineralização do esmalte dentário. Foram utilizados 90 fragmentos de terceiros molares humanos irrompidos, selecionados por microdureza superficial e isolados com resina composta deixando apenas uma área de 4x4mm exposta. Em seguida foram desmineralizados por 32 h e 60 espécimes tiveram metade da área (2x4mm) isolada. Os espécimes foram divididos aleatoriamente em seis grupos/subgrupos, de acordo com os tratamentos propostos: G1-Controle (sem tratamento); G2- CPP-ACP, G3-verniz fluoretado Duraphat®; A - sem laser, B- tratamento com laser de diodo (0,7W, 70mJ, 10Hz). Na sequência foi realizado ciclo de pH para indução de desmineralização por oito dias. A solução desmineralizante de cada espécime foi armazenada para análise do cálcio por espectrometria de absorção atômica (n=10). Os espécimes foram seccionados ao meio, uma das metades foi analisada por microdureza longitudinal (n=10) e a outra por rugosidade (n=10) e morfologia superficial (n=10). Para a análise por Tomografia de Coerência Óptica (OCT) foi empregado n=5 por grupo/subgrupo e realizou-se a OCT em 2 fases, sendo a primeira após a desmineralização por 32h e a segunda após os tratamento/ciclagem de pH. Para a microdureza empregou-se a variação percentual da dureza, para a espectrometria de absorção atômica empregou-se a quantidade total de cálcio perdido, para a rugosidade superficial e OCT empregou-se a diferença entre os valores da desmineralização inicial e os valores obtidos após a ciclagem. Os dados foram analisados pelo método não paramétrico de Kruskal-Wallis e o teste de Dunn para diferenciação das médias (&prop;= 5%). Pode-se observar que ocorreu maior perda de dureza, de cálcio e maior profundidade de desmineralização nos grupos controle quando comparados com os grupos que receberam os tratamentos (G1A&asymp;G1B e &ne; G2A&asymp;G2B&asymp;G3A&asymp;G3B) sendo estatisticamente diferente (p<0,05). Maior rugosidade foi encontrada nos grupos G1A, G1B e G3A e foi estatisticamente significante (p<0,05). O fator laser não influenciou nas propriedades analisadas. Na microscopia confocal a laser não foram observadas áreas de fusão ou qualquer alteração na estrutura do esmalte irradiado. Pode-se concluir que o laser associado à CPP-ACP ou verniz fluoretado não foi capaz de aumentar a resistência ácida do esmalte submetido a ciclos de pH. Os tratamentos, MI Paste e verniz fluoretado foram eficazes independente da utilização do laser. / The aim of this study was to assess the effect of diode laser in combination with CPP-ACP/ fluoride varnish on enamel resistance to demineralization. Ninety fragments of unerupted human 3rd molar teeth were selected according to superficial microhardness and covered with compound resin, with only a 4x4mm area left exposed. They were then demineralized for 32 hours and 60 specimens had their exposed area halved. The specimens were randomly divided into 6 groups/subgroups, in line with the proposed treatments: G1-Control (no treatment); G2- MI Paste®, G3- fluoride varnish Duraphat® 5%; A - no laser, B- treatment with diode laser (0.7W, 70mJ, 10Hz). Afterwards, an 8-day pH cycle was carried out to induce demineralization. The demineralizing solution for each specimen was stored for the purpose of atomic absorption spectometry for the determination of calcium (n=10). The specimens were cut in half. The first half was analyzed using the criterium of longitudinal microhardnesss (n=10), the second the criterium of roughness (n=10) and superficial morphology (n=10). Optical coherence tomography (OCT) was used to assess group/subgroup for n=5. OCT was carried out at 2 moments, after a 32-hour demineralization period and post pH treatment/cycling. For microhardness we used percent change in hardness, for atomic absorption spectrometry the total amount of calcium lost, for superficial hardness and OCT the difference between the figures seen after initial demineralization and those obtained post cycling. The data were analyzed using the nonparametric Kruskal-Wallis Multiple-Comparison Z-Value Test and the Dunn test for distinguishing mean values (&prop;= 5%). Greater loss of hardness, greater loss of calcium, and deeper demineralization were seen in the control groups, when compared to those groups that underwent treatment (G1A&asymp;G1B and &ne; G2A&asymp;G2B&asymp;G3A&asymp;G3B). Greater roughness was found in groups G1A, G1B, and G3A, and it was statistically significant (p<0.05). Overall, laser use did not exert influence upon the analyzed properties. Confocal laser scanning microscopy did not reveal areas of fusion or any alteration in the structure of irradiated enamel. One can conclude that associating laser to CPP-ACP or fluoride varnish did not increase enamel resistance to acid when it underwent pH cycles. The treatments, MI Paste, and fluoride varnish were effective, regardless of the use of laser.

Peptide nucleic acids (PNAs) were used as encoding tags to enable the analysis of peptide libraries by PNA/DNA hybridisation onto DNA microarrays. This allowed entire peptide libraries to be organised and sorted in a two dimensional format whereby all library members could be interrogated and analysed on a one-byone basis. In this thesis, PNA-encoded peptide libraries, generated by split-and-mix library synthesis, were screened for a variety of functions. Peptide sequences identified from the screening of a PNA-encoded library were analysed in detail as the first specific substrates for chymopapain. A new PNAencoded library consisting of D-amino acids was synthesised and screened with a number of proteases in attempts to identify novel/unusual substrates. PNA-encoded libraries were also used in the screening of peptide libraries for other activities. Thus substrates for catalyst-free Hüisgen cycloaddition were identified following the reaction between an alkyne modified peptide library and azidofluorescein, while cell-penetrating peptides were identified by hybridization of an internalized encoded library onto a DNA microarray.