O poli(ε-caprolactona) (PCL) é um polímero biocompatível e biodegradável, aprovado pelo Food and Drug Administration (FDA) para ser usado como biomaterial. Diversos estudos utilizando sua forma linear ou ramificada têm demonstrado resultados promissores para seu uso no desenvolvimento de dispositivos médicos e em aplicações na área farmacêutica. O objetivo deste trabalho foi utilizar o PCL com estrutura estrelada (PCLE) para obter microesferas biorreabsorvíveis. Primeiramente realizou-se a avaliação das propriedades físico-químicas do PCLE por meio da cromatografia de permeação em gel (GPC), ressonância magnética de prótons (1H-RMN) e carbono (13C-RMN), calorimetria exploratória diferencial (DSC) e espectrometria por infravermelho com transformada de Fourier (FT-IR). A avaliação toxicológica do PCLE foi obtida por meio do ensaio de citotoxicidade utilizando células CHO-K1 e o corante vital 5-(3-carboximethoxifenil)-2-(4,5-dimetiltiazolil)-3-(4-sulfofenil) tetrazolium e do acoplador de elétrons fenazine metilssulfato (MTS/PMS). O ensaio de biodegradação foi conduzido em pH 7,4 na presença de lipase a 37 ºC. Após essas análises o PCLE foi utilizado para preparação de esferas por meio de emulsão complexa A/O/A. O PCLE foi caracterizado como um polímero de baixa massa molar, com dispersão de tamanho unimodal e cerca de 68,8 % de suas moléculas apresentaram estrutura estrelada com três braços. Em relação às propriedades térmicas o PCLE apresentou temperatura de fusão de 57,3 ºC e temperatura de transição vítrea de -54,3 ºC. A avaliação da citotoxicidade mostrou que o extrato de PCLE é compatível com o metabolismo celular. As microesferas obtidas a partir do PCLE, por emulsão A/O/A apresentaram polidispersão de tamanho. / The poly(ε-caprolactone) (PCL) is a biocompatible and biodegradable polymer which has been approved by Food and Drug Administration (FDA). Many studies that are using its linear or branched form have showed promising results for medical devices and controlled drug delivery applications. The aim of this research was the use of star-shaped PCL (PCLE) to prepare bioreabsorbable microspheres. At first, the physical-chemical properties were characterized by Gel Permeation Chromatography (GPC), Protons Resonance Magnetic Nuclear (1H-RMN), Carbon Resonance Magnetic Nuclear (13C-RMN), Differential Scanning Calorimetry (DSC) and Fourier Transformed Infrared Spectroscopy (FT-IR). The toxicological property was investigated by colorimetric assay using CHO-K1 cells and the vital dye (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) (MTS) and the electron acceptor phenazine methosulfate (PMS). The biodegradation behavior was evaluated in the presence of lipase at 37 ºC and pH 7.4. The microspheres were prepared by complex emulsion W/O/W. The PCLE was characterized as low molecular weight polymer with monomodal distribution and about 68,8 % of the molecules were three-arm branched. The melting and glass transition temperatures were 57.3 ºC and -54.3 ºC, respectively. The cytotoxicity evaluation showed that PCLE extract was cell compatible. The obtained microspheres showed diameter polydispersity.

Submitted by Filipe dos Santos (fsantos@pucsp.br) on 2017-03-24T11:46:39Z No. of bitstreams: 1 Luiza Mulin Vaz.pdf: 1857515 bytes, checksum: 90cfcee01d5a7a029b76227041d9a0a8 (MD5) / Made available in DSpace on 2017-03-24T11:46:39Z (GMT). No. of bitstreams: 1 Luiza Mulin Vaz.pdf: 1857515 bytes, checksum: 90cfcee01d5a7a029b76227041d9a0a8 (MD5) Previous issue date: 2017-03-17 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Behavioral analysts have been concerned with evaluating the effect of different learning histories over the sensitivity to the change of contingencies. The present research has investigated the effect of three variables over the sensitivity to the change of contingencies: (1) learning histories, by rules or contingencies; (2) the degree of instructional specificity (general instruction and specific instruction); and (3) maintenance or change of the instruction between phases. Twenty participants were assigned to one of five experimental groups, that were different by the acquirement of repertoire in Phase 1: two groups were exposure to general instruction; other two groups were exposure to specific instruction and one group were exposure to learning by contingencies (minimum instruction). In Phase 2, block 1, the same type of instruction was maintained for three groups; for the other two groups, the instruction was shifted to a minimum instruction. In Phase 2, block 2, the reinforcement contingency was modified without any previous warning. In both phases, a first order matching-to-sample task procedure was programmed in the computer. In Phase 1, was reinforced to choose one of the comparison stimuli that shared the property “equal in shape or in color” with the sample stimulus. This phase contained three sessions, of 36 trials each. Phase 2 contained three sessions, each divided into two blocks. Block 1 corresponded to the first 10 trials and Block 2 corresponded to the following 26 trials. In each block, a contingency would take effect. In blocks 1, there was instruction presentation and the contingency in effect was the same one of the Phase 1 (correct relation was the property: “equal in shape or in color”). In blocks 2, there was no instruction presentation and was reinforced to choose one of the comparison stimuli that did not shared any property with the sample stimulus. This change of contingencies occurred without previous warning. The results showed that the group exposed to learning by contingencies and one of the groups exposed to general instruction showed the most sensitivity when the contingencies were shifted. While one of the groups exposed to specific instruction showed insensitivity when the contingencies were shifted. This result indicates that learning histories by contingencies and by general instruction promotes the sensitivity to the change of contingencies. In the other hand, the learning history by specific instruction produces less sensitivity to the change of contingencies. In general, the groups that were exposed to minimal instruction in Phase 2 (blocks 1) showed more sensitivity to the change of contingencies when compared to the groups that were exposed to general or specific instruction between the two phases / Analistas do comportamento têm se preocupado em avaliar o efeito de diferentes histórias de aprendizagem sobre a sensibilidade a mudanças nas contingências. A presente pesquisa teve o objetivo de investigar o efeito de algumas variáveis na sensibilidade à mudança nas contingências, sendo elas: (1) histórias de aprendizagem, por regras ou por contingências; (2) histórias de aprendizagem por regras mais ou menos específicas (instrução geral e instrução específica); e (3) manutenção ou mudança no tipo de instrução apresentada nas diferentes fases. Vinte participantes foram alocados em cinco grupos experimentais, definidos de acordo com a forma de aquisição do repertório na Fase 1: aprendizagem por instrução geral (dois grupos); aprendizagem por instrução específica (dois grupos); e aprendizagem por contingências – instrução mínima (um grupo). Na Fase 2, bloco 1, o mesmo tipo de instrução foi mantido para três grupos; para os outros dois grupos, a instrução foi alterada para mínima. Na Fase 2, bloco 2, ocorreu mudança não-sinalizada das contingências. Nas duas fases, a tarefa consistiu em um procedimento de escolha de acordo com o modelo e foi realizada no computador. Na Fase 1, era reforçada a resposta de clicar sobre o estímulo comparação igual ou em forma ou em cor ao estímulo modelo. Essa fase conteve três sessões, de 36 tentativas cada. A Fase 2 conteve três sessões, cada uma dividida em dois blocos. O bloco 1 correspondia às primeiras 10 tentativas e o Bloco 2 correspondia às 26 tentativas seguintes. Em cada bloco, uma contingência entrava em vigor. Nos blocos 1, havia apresentação de instrução e era reforçada a resposta de clicar sobre o estímulo comparação igual em forma ou em cor ao estímulo modelo. Nos blocos 2, não havia instrução e era reforçada a resposta de clicar sobre o estímulo comparação diferente do estímulo modelo. Essa mudança de contingência foi realizada sem qualquer sinalização. Os resultados mostraram que o grupo em que a aquisição do repertório se deu pelas contingências e um dos grupos em que a aquisição de deu por instrução geral foram os que ficaram mais sensíveis à mudança nas contingências, enquanto um dos grupos em que a aquisição do repertório se deu por instrução específica apresentou insensibilidade à mudança nas contingências. Esse resultado indica que, quando há mudança nas contingências, histórias de aprendizagem por contingências e por instrução geral favorecem a mudança no responder; já a aprendizagem por instrução específica torna o responder pouco sensível a mudança. Em geral, os grupos que receberam instrução mínima na Fase 2 (blocos 1) mostraram-se mais sensíveis à mudança nas contingências, quando comparados aos grupos que receberam instrução geral ou específica nas duas fases

Chromosomal replication is a source of spontaneous DNA double-strand breaks (DSBs). In E. coli, DSBs are repaired by homologous recombination using an undamaged sister template. During repair, the RecA protein polymerizes on single-stranded DNA generated at the site of the DSB and catalyses the search for sequence homologies on the undamaged sister template. This study utilized fluorescence microscopy to investigate the spatial and temporal dynamics of the RecA protein at the site of a replication-dependent DSB generated at the lacZ locus of the E. coli chromosome. The DSB was generated by SbcCD-mediated cleavage of a hairpin DNA structure formed on the lagging strand template of the replication fork by a long palindromic sequence. The tandem insertion of a recA-mCherry gene with the endogenous recA gene at the natural chromosomal locus produced no detectable effect on cell viability in the presence of DSB formation. During repair, the fluorescently-labelled RecA protein formed a transient focus, which was inferred to be the RecA nucleoprotein filament at the site of the replication-dependent DSB. The duration of the RecA focus at the site of the DSB was modestly reduced in a ΔdinI mutant and modestly increased in a ΔuvrD or ΔrecX mutant. Most cells underwent a period of extended cohesion of the sister lacZ loci after disappearance of the RecA focus. Segregation of the sister lacZ loci was followed by cell division, with each daughter cell obtaining a copy of the fluorescently-labelled lacZ locus. The RecA focus at the site of the DSB was observed predominantly between the mid-cell and the 1⁄4 position. In the absence of DSB formation, the lacZ locus exhibited dynamic movement between the mid-cell and the 1⁄4 position until the onset of segregation. Formation of the DSB and initiation of repair occurred at the spatial localization for replication of the lacZ locus while the downstream repair events occurred very close to the mid-cell. Genomic analysis of RecA-DNA interactions by ChIP-seq was used to demonstrate that the RecA focus at the lacZ locus was generated by the repair of the palindrome-induced DSB and not the repair of one-ended DSBs emanating from stalled replication forks at the repressor-bound operator arrays. This study has shown that the repair of a replication-dependent DSB occurs exclusively during the period of cohesion of the sister loci and the repair is efficiently completed prior to segregation of the two sister loci.

The TRUShape 3D Conforming File (TRUShape), a novel, S-shaped nickel-titanium (NiTi) rotary file, was developed to facilitate cleaning and shaping of irregular-shaped root canals. The purpose of this study was to evaluate the shaping ability of TRUShape compared to Vortex Blue (VB) when used in non-round, oval-shaped root canals by micro-computed tomography (MCT). Thirty single-rooted human mandibular premolar teeth with radiographically similar root canal size and curvature were randomly allocated to two groups (N=15), and mechanically prepared with TRUShape or VB. Each tooth was submitted to MCT at 20 μm resolution at three time intervals: before shaping, and after shaping to an intermediate apical size 30 and a final apical size 40. Three-dimensional data sets were superimposed and evaluated for root canal volume, surface area, and treated surface. Matched axial slices in the apical, middle, and coronal root thirds were evaluated for area, roundness, and canal transportation expressed as center of mass shift (CMS). Data were statistically analyzed using parametric and non-parametric tests. Root canal volumes increased similarly and significantly overall (p< 0.001; from an initial volume of 7.3±3.5 mm3 to an intermediate volume of 8.7±3.1 mm3 and a final volume of 9.9±3.0 mm3). Treated canal surface was significantly larger in the TRUShape group at both apical sizes 30 and 40 with 72±15% vs. 55±23% and 85±12% vs. 71±20% non-static voxels for TRUShape and VB, respectively (p< 0.05). Canal transportation was less than 100 μm in all but 8 out of 90 cross sections and was not significantly different between groups. This MCT study demonstrated the TRUShape 3D Conforming File to be effective in the mechanical preparation, specifically, the surface treatment, of single-rooted premolars with non-round, oval-shaped root canals. Funding was provided by the American Association of Endodontists (AAE) Foundation and the Department of Endodontics at the University of Iowa, College of Dentistry.

The collocation Trefftz method (CTM) proposed in [36] is employed to annular shaped domains, and new error analysis is made to yield the optimal convergence rates. This popular method is then applied to the special case: the Dirichlet problems on circular domains with circular holes, and comparisons are made with the null field method (NFM) proposed , and new interior field method (IFM) proposed in [35], to find out that both errors and condition numbers are smaller. Recently, for circular domains with circular holes, the null fields method (NFM) is proposed by Chen and his groups. In NFM, the fundamental solutions (FS) with the source nodes Q outside of the solution domains are used in the Green formulas, and the FS are replaced by their series expansions. The Fourier expansions of the known or the unknown Dirichlet and Neumann boundary conditions on the circular boundaries are chosen, so that the explicit discrete equations can be easily obtained by means of orthogonality of Fourier functions. The NFM has been applied to elliptic equations and eigenvalue problems in circular domains with multiple holes, reported in many papers; here we cite those for Laplace¡¦s equation only (see [18, 19, 20]). For the boundary integral equation (BIE) of the first kind, the trigonometric functions are used in Arnold [4, 5], and error analysis is made for infinite smooth solutions, to derive the exponential convergence rates. In Cheng¡¦s Dissertation [21, 22], for BIE of the first kind, the source nodes are located outside of the solution domain, the linear combination of fundamental solutions are used, and error analysis is made only for circular domains. This fact implies that not only can the CTM be applied to arbitrary domains, but also a better numerical performance is provided. Since the algorithms of the CTM is simple and its programming is easy, the CTM is strongly recommended to replace the NFM for circular domains with circular holes in engineering problems.

Located on one of the highly active seismic fault systems in the world, the building stock in Turkey is mainly composed of reinforced concrete frames with 4-5 stories. Due to design and construction deficiencies resulting from the use of unqualified personnel and insufficient supervision, many of these buildings lack lateral stiffness, ductility and strength. For many structures, there is a need to alleviate these deficiencies by means of some rehabilitation techniques prior to earthquakes. One approach also used very widely in Turkey is to fill some of the frame bays by cast-in-place R/C panels. The procedure appears to be very practical at first glance. It also appears to be very economical as far as the production of the panels is concerned. However, the production phase is slow, dirty, destructive and disruptive to occupants. Moreover, it requires relatively skilled personnel and special equipment. Therefore, the real life experience shows that the actual cost in practice is much higher when all other hidden costs are taken into account. The aim of this experimental study is to explore the potential of using infill walls made of custom shaped and high strength concrete blocks as a simpler and more practical alternative to cast-in-place R/C panels to increase the lateral load bearing capacity of frame structures. The effectiveness of FRCM (Fiber Reinforced Cementitous Matrix) system on damaged structures is also investigated in this study.

A new method is proposed that provides simple and effcient design and analysis algorithm for microstrip antennas with arbitrary patch shapes. The proposed procedure uses the mutiport network model (MNM) where the antenna is considered as a cavity bounded by perfect electric conductors on the top and the bottom surfaces and perfect magnetic conductor on the side surfaces. Ports are defined along the periphery of the patch, and the impedance matrix representing the voltage induced at one port due to a current source at another port, is obtained through the use of the 2-D Green&rsquo / s function corresponding to the cavity. For the MNM analysis of patches with irregular shapes such as slotted structures, the segmentation/desegmentation methods are utilized since the Green&rsquo / s function expressions are available only for regularly shaped cavities. To speed up the analysis and to develop a design procedure, vector Pade approximation is used in order to approximate the antenna impedance matrix as a rational function of two polynomials. When the approximation is performed with respect to frequency, the roots of the polynomial at the denominator provides the resonant frequencies of the antenna. The design algorithm is applicable when the approximation variable is changed to one of the dimensions of the patch that need to be optimized. Because for this case, the roots of the denominator polynomial correspond to optimum dimensions of the antenna where it resonates.

Cylindrically conformal microstrip antennas are investigated. Two different structures, namely proximity coupled and E-shaped microstrip antennas are analyzed and information about the design parameters is obtained by means of parametric study. With these structures, cylindrical arrays, having omnidirectional radiation in the circumferential plane of the cylinder, are designed. Proximity coupled cylindrical arrays operate in the 2.3-2.4 GHz aeronautical telemetry band with approximately 4% bandwidth. On the other hand, more than 30% bandwidth is obtained by E-Shaped cylindrical array antenna structure, which also includes the commercial telemetry band. In order to verify the simulation method, a fabricated antenna in literature is simulated and acceptable agreement with simulation and fabrication results obtained.

X BAND TWO LAYER PRINTED REFLECTARRAY WITH SHAPED BEAM &Uuml / &ccedil / &uuml / nc&uuml / , G&ouml / khan MSc., Department of Electrical and Electronics Engineering Supervisor: Prof. Dr. H. &Ouml / zlem Aydin &Ccedil / ivi October, 2011, 110 pages X-band cosecant square shaped beam microstrip reflectarray is designed, fabricated and measured. Unit element of the reflectarray is in stacked patch configuration. With the aim of designing shaped beam pattern, phase-only synthesis method based on genetic algorithm is used. Phases of reflected electric field from antenna elements are adjusted by changing the dimensions of the patches. Unit cell simulations are performed using periodic boundary conditions and assuming infinite array approach to obtain reflection phase curves versus patch size. Then full reflectarray surface and its feed are designed and fabricated. Radiation patterns are measured in spherical near field range and results are compared with simulations. It is shown that the antenna is capable to operate in a band of 8.6 - 9.7 GHz.

本論文是以Kellerman (1978) 的U型學習理論為基礎做擴大研究。本篇論文旨在探討英文程度不同的中文為母語之人士，在學習非賓格不及物動詞時是否也會出現U型曲線，除此之外，非賓格不及物動詞與非賓格及物動詞，被動態，主詞生命度之間的互動也將做討論。 在這個研究中，我們採用語法判斷(Grammaticality judgment)來測試受測者對於非賓格不及物動詞的理解和中英轉譯(Chinese to English translation)來測試受測者對於主詞生命度和主被動態之間的影響。此研究共有123位受測者，他們根據學習英文的長短被分為四個組別，分別是低、低中、中、與中高程度。 此研究可歸納為以下結論。(1) 不同英文程度的中文為母語之人士，在學習英文非賓格不及物動詞時也會出現U型曲線。此即意味著U型曲線不僅僅出現在母語為荷蘭語學習非賓格及物動詞Break的學習上，更可擴大到母語為中文學習非賓格不及物動詞上。(2) 中文為母語之人士無法正確使用非賓格及物動詞，並且會把非賓格及物動詞當作非賓格不及物動詞。(3) 在學習非賓格不及物動詞中，主詞生命度確實會影響學習者使用主被動態之不同。當主詞有生命時，句子傾向使用主動態，當主詞是無生命時，句子傾向使用被動態。 / The study is based on Kellerman’s (1978) U-shaped leaning on break to do further study. The study aims to examine if the learning of non-alternating unaccsatives for L2 Chinese learners of English with different proficiency presents a U-shaped curve. In addition, the interactions among alternating unaccusatives, non-alternating unaccusatives, passives and animacy effect are discussed as well. In the study, we use grammaticality judgment task to test participants’ understanding of non-alternating unaccusatives, and adopt Chinese to English translation task to test animacy effect in non-alternating unaccusatives. 123 participants involve the experiment of the study. Among these participants, they are classified as four groups, low, low-intermediate, intermediate, and high-intermediate, according to how long they studied English. The results of the study are summarized as follows. (1) There is a U-shaped curve in learning of non-alternating unaccusatives for L2 Chinese speakers learning English. It suggested that U-shaped learning is not only in alternating unaccusatives break in L1 Dutch but also in non-alternating unaccusatives in L1 Chinese. (2) For L2 learners, they are unable to use alternating unaccusatives correctly and tend to view alternating unaccusatives as non-alternating ones. (3) Animacy effect does influence the choices of voice forms. The study showed that participants tend to use active voice while the subject is animate and prefer to use passive voice while the subject is inanimate.