DARBO TIKSLAS Įvertinti ir palyginti pacientų gyvenimo kokybę po laparoskopinių ir atvirųjų dvylikapirštės žarnos opos užsiuvimo operacijų. TYRIMO OBJEKTAS IR METODAI Buvo tiriami 1996 – 2004 metais Vilniaus greitosios pagalbos universitetinėje ligoninėje operuoti pacientai dėl prakiurusios dvylikapirštės žarnos opos. Ištyrėme 12 pacientų, kuriems buvo atlikta laparoskopinė opos užsiuvimo operacija ir 13 pacientų, kurie buvo operuoti atviru būdu. Gyvenimo kokybė buvo tiriama naudojant adaptuotą PSO – 100 klausimyną. Statistinė duomenų analizė buvo atlikta panaudojant SPSS 12.0.1 programinį paketą. REZULTATAI Laparoskopiškai operuotų pacientų grupėje 50,0% respondentų savo gyvenimo kokybę įvertino vidutiniškai, o 33,3% - gerai. Įvertinus gyvenimo kokybę atviru būdu operuotų pacientų grupėje buvo nustatyta, kad 53,8% tirtųjų asmenų ją įvertino vidutiniškai, o 38,5% įvertino gerai. IŠVADOS Abiejų tirtųjų grupių gyvenimo kokybė statistiškai reikšmingai nesiskyrė ir buvo įvertinta dažniausiai vidutiniškai . / AIM OF STUDY To evaluate and compare quality of life in patient‘s after duadenal perforated ulcer laparoscopic and open surgery repair. OBJECTIVE AND METHODS 25 patients participated in study. The study was carried on 12 patients who had duadenal perforated ulcer laparoscopic and 13 open surgery repair managed in Vilnius University Emergency hospital between 1996 and 2004. Quality of life was assessed using WHOQOL–100 Questionnaire. Statistical data analysis performed using SPSS 12.0.1 analystical software. RESULTS In group with laparoscopically managed perforated ulcer 50,0 % of respondents assessed their quality of life as neither poor nor good, and 33,3 % as good. In group of open surgery managed perforated ulcer 53,8 % of respondents assessed their quality of life as neither poor nor good, and 38,5 % as good. CONCLUSIONS The results showed that quality of life in both groups was statistically equal and in most cases assessed as neither poor nor good.

Neisseria gonorrhoeae infections are of major concern in areas of low socioeconomic status in both developed and developing nations. N. gonorrhoeae colonizes the genital tract by adhering to mucosal tissues through a number of adhesins, including the colony opacity-associated (Opa) proteins. Despite the random phase-variable expression of Opa proteins, 95% of clinical isolates express Opa variants that bind to the carcinoembryonic antigen-related cellular adhesion molecule 1 (CEACAM1), suggesting an essential role in vivo. Interestingly, even though gonorrhea is characterized by an intense inflammatory response, the organism is capable of evading the adaptive immune response. In previous studies by the Gray-Owen group, it has been established that certain gonococcal Opa variants bind CEACAM1 expressed by CD4+ T helper lymphocytes and, thereby, reduce their activation and proliferation. Since T cells are essential in establishing immune memory, inhibition of T cell function could explain the deficit in immune memory following gonococcal infection. In this thesis, I describe my studies to elucidate how CEACAM1 inhibits T cell activation on a molecular level. In Chapter 2, I demonstrate that outer membrane vesicles (OMVs) naturally shed by OpaCEA-expressing Neisseria sp. effectively inhibit CD4+ T cell activation, implicating a role for OMVs during infection and establishing that the Opa proteins do not have to be expressed in the context of the bacterium in order to elicit an inhibitory effect. In Chapter 3, I describe early steps in the CEACAM1-dependent inhibitory signaling cascade elicited when N. gonorrhoeae binds to CD4+ T cells. Finally, in Chapter 4, I show that a dynamic monomer-dimer equilibrium controls CEACAM1 function in epithelial cells and lymphocytes. Combined, the results presented in this thesis allow the derivation of a model to explain how CEACAM1 controls CD4+ T cell function at a molecular level.

This thesis contains two major components of research: numerical simulation of optical-parametric amplification cross correlation of Frequency-Resolved Optical Gating (OPA-XFROG) and numerical simulation of GRENOUILLE and its related issues. Recently, an extremely sensitive technique--OPA-XFROG has been developed. A short pump pulse serves as the gate by parametrically amplifying a short segment of the signal pulse in a nonlinear crystal. High optical parametric gain makes possible the complete measurement of ultraweak, ultrashort light pulses. Unlike interferometric methods, it does not carry prohibitively restrictive requirements, such as perfect mode-matching, perfect spatial coherence, highly stable absolute phase, and a same-spectrum reference pulse. We simulate the OPA-XFROG technique and show that by a proper choice of the nonlinear crystal and the noncollinear mixing geometry it is possible to match the group velocities of the pump, signal, and idler pulses, which permits the use of relatively thick crystals to achieve high gain without measurement distortion. Gain bandwidths of ~100 nm are possible, limited by group velocity dispersion. In the second part of the thesis, we numerically simulate the performance of the ultrasimple ultrashort laser pulse measurement device- GRENOUILLE. While simple in practice, GRENOUILLE has many theoretical subtleties because it involves the second-harmonic generation of relatively tightly focused and broadband pulses. In addition, these processes occur in a thick crystal, in which the phase-matching bandwidth is deliberately made narrow compared to the pulse bandwidth. We developed a model that include all sum-frequency-generation processes, both collinear and noncollinear. We also include dispersion using the Sellmeier equation for the crystal BBO. Working in the frequency domain, we compute the GRENOUILLE trace for practical-and impractical-examples and show that accurate measurements are easily obtained for properly designed devices. For pulses far outside a GRENOUILLE's operating range (on the long side), we numerically deconvolve the GRENOUILLE trace with the response function of GRENOUILLE to improve its spectral resolution. In the last part of the thesis, we simulate the second harmonic generation with tightly focused beams by use of lens. Thus, we are able to explain the `weird' focusing effect that has been a `puzzles' for us in the GRENOUILLE measurement.

Neisseria gonorrhoeae infections are of major concern in areas of low socioeconomic status in both developed and developing nations. N. gonorrhoeae colonizes the genital tract by adhering to mucosal tissues through a number of adhesins, including the colony opacity-associated (Opa) proteins. Despite the random phase-variable expression of Opa proteins, 95% of clinical isolates express Opa variants that bind to the carcinoembryonic antigen-related cellular adhesion molecule 1 (CEACAM1), suggesting an essential role in vivo. Interestingly, even though gonorrhea is characterized by an intense inflammatory response, the organism is capable of evading the adaptive immune response. In previous studies by the Gray-Owen group, it has been established that certain gonococcal Opa variants bind CEACAM1 expressed by CD4+ T helper lymphocytes and, thereby, reduce their activation and proliferation. Since T cells are essential in establishing immune memory, inhibition of T cell function could explain the deficit in immune memory following gonococcal infection. In this thesis, I describe my studies to elucidate how CEACAM1 inhibits T cell activation on a molecular level. In Chapter 2, I demonstrate that outer membrane vesicles (OMVs) naturally shed by OpaCEA-expressing Neisseria sp. effectively inhibit CD4+ T cell activation, implicating a role for OMVs during infection and establishing that the Opa proteins do not have to be expressed in the context of the bacterium in order to elicit an inhibitory effect. In Chapter 3, I describe early steps in the CEACAM1-dependent inhibitory signaling cascade elicited when N. gonorrhoeae binds to CD4+ T cells. Finally, in Chapter 4, I show that a dynamic monomer-dimer equilibrium controls CEACAM1 function in epithelial cells and lymphocytes. Combined, the results presented in this thesis allow the derivation of a model to explain how CEACAM1 controls CD4+ T cell function at a molecular level.

In this paper, we present the results of the design and fabrication of a 12 channel nano-membrane-based optical phased array that allows for large angle beam steering operating at wavelength=1.55µm. Our device is fabricated on silicon-on-insulator using standard CMOS process. By implementing unequally spaced waveguide array elements, we can relax the half-wavelength spacing requirement for large angle beam steering, thereby avoiding the optical coupling between adjacent waveguides and reducing the side-lobe-level of the array radiation pattern. 1D beam steering of tranverse-electric polarized single mode light is designed to be achieved thermo-optically through the use of thin film metal phase shifters. / text

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As coberturas de hidroxiapatita (HAp) são utilizadas para aumentar a osteointegração em implantes de titânio (Ti), devido à sua capacidade de promover a biomineralização para corrigir defeitos esqueléticos e craniofaciais. O objetivo desta pesquisa foi avaliar a influência dos revestimentos sobre culturas primárias de osteoblastos. Na primeira fase de estudos, desenvolvemos uma nova abordagem de revestimento baseada em filmes Langmuir-Blodgett (LB) de dihexadecilfosfato (DHP) e ácido octadecilfosfônico (OPA) depositados em discos Ti, e crescimento subsequente de cristais de HAp. Analisamos a viabilidade dos osteoblastos, a atividade da fosfatase alcalina (ALP) e a formação da matriz mineralizada por métodos colorimétricos e a morfologia das culturas por microscopia eletrônica de varredura e microscopia confocal. Os resultados revelaram que o revestimento DHP/HAp aumentou a viabilidade dos osteoblastos até 150% em comparação com o controle em todos os dias testados. O revestimento OPA/HAp promoveu a maior viabilidade ao 14 dias (190%). A atividade de ALP foi aumentada apenas pelo revestimento de DHP/HAp ao 14º dia em comparação com o controle e Ti limpo. A microscopia eletrônica de varredura e as microfotografias confocais revelaram diferenças morfológicas entre os osteoblastos cultivados em ambos os revestimentos, aumentando o seu número e o espalhamento. O revestimento de DHP/HAp aumentou a produção de nódulos biomineralizados. O ensaio de biomineralização pela técnica do Vermelho de Alizarina mostrou que o revestimento de OPA/HAp possuía uma concentração de cálcio (Ca2+) 1,88 vezes superior à cobertura de DHP/HAp. Uma vez que a literatura relata que o Ca2+ pode estimular ou inibir a atividade da ALP e, consequentemente, o processo de biomineralização, as diferenças no comportamento desses dois revestimentos podem estar relacionadas às diferenças de concentração de superfície de Ca2+. O bom desempenho do revestimento de DHP/HAp pode estar relacionado às características da composição química, adicionada à técnica de deposição LB. Na segunda fase da pesquisa, as monocamadas de Langmuir de DHP e dipalmitoil fosfatidilcolina (DPPC) foram testadas e utilizadas para incorporar o paratormônio 1-34 (PTH 1-34) (DHP/Ca+PTH e DPPC/Ca+PTH, respectivamente). Também foram testadas as ações dos revestimentos DHP/HAp com PTH em solução (DHP/HAp+PTH S) e gotejado (DHP/HAp+PTH G) em culturas de osteoblastos. Um potencial zeta negativo em pH 7,4 foi encontrado (-14,9 mV) para o PTH 1-34. A isoterma de DPPC mostrou um aumento da área mínima ocupada por molécula lipídica após a injeção de PTH na subfase de água (50 ?L de solução 0,5 mg/mL) em 10,97 Å2, o que pode ser devido à inserção de PTH neste filme. A área mínima de DHP foi alterada em 2,3 Å2, o que não é estatisticamente significativo. A análise de QCM mostrou um depósito de 72,5 ng de PTH em filme de DPPC e 29,3 ng de PTH em filme de DHP para cada 25 ?g de PTH injetado na cuba de Langmuir. A viabilidade celular e a formação da matriz mineralizada de culturas de osteoblastos crescidas em DHP/Ca+PTH e revestimentos DPPC/Ca+PTH diminuíram quando comparadas com Ti limpo. Os revestimentos DHP/HAp+PTH S e DHP/HAp+PTH G mostraram ser tão eficientes quanto o Ti DHP/HAp para estimular o processo de biomineralização. Mas a cobertura de DHP/HAp+PTH G aumentou a viabilidade dos osteoblastos e a formação de matriz mineralizada quando comparada com Ti DHP/HAp. Esta é uma cobertura inovadora que abre precedentes para o uso da técnica de gotejamento em HAp para outros hormônios e drogas que agem sobre o tecido ósseo. / Due to their ability to promote biomineralization, Hydroxyapatite (HAp) coatings are used to increase the osteointegration in titanium (Ti) implants, in order to correct skeletal and craniofacial defects. The objective of the research was to evaluate the influence of the coatings on osteoblasts primary cultures. In the first phase of the research we developed a new coating approach based on Langmuir-Blodgett (LB) films of dihexadecyl phosphate (DHP) and octadecylphosphonic acid (OPA) deposited on Ti discs and subsequent growth of HAp crystals. We analyzed the osteoblast viability, alkaline phosphatase (ALP) activity and mineralized matrix formation by colorimetric methods, and the morphology of the cultures by scanning electron microscopy and confocal micrographies. The results revealed that the DHP/HAp coating increased osteoblast viability up to 150% compared to the control at all days tested. The OPA/HAp coating promoted the highest viability on the 14th day (190%). The ALP activity was enhanced only by the DHP/HAp coating on the 14th day compared to control, and clean Ti. To explore the morphology of the cells, the scanning electron microscopy and confocal micrographies were obtained, and revealed morphological differences between osteoblasts grown on both coated Ti compared to clean Ti. Both coatings increased the number and spreading of osteoblasts, while the DHP/HAp coating enhanced the production of biomineralized nodules. The Alizarin Red assay showed that OPA/HAp coating has 1.88 times higher calcium (Ca2+) concentration than DHP/HAp. The same test confirmed the increase of mineralization only by DHP/HAp coating compared to clean Ti. Since literature reports that Ca2+ can stimulate or inhibit the ALP activity and consequently, the biomineralization process, the differences on the behavior of these two coatings could be related to the Ca2+ surface concentration differences. The good performance of the DHP/HAp coating can be explained due to the characteristics of the chemical composition, added to the LB deposition technique. In the second phase of the research, Langmuir monolayers of DHP and dipalmitoyl phosphatidylcholine (DPPC) was tested and used to incorporate 1-34 parathyroid hormone (PTH 1-34) (DHP/Ca+PTH, and DPPC/Ca+PTH, respectively). DHP/HAp coatings with PTH in solution (DHP/HAp+PTH S), and dropped (DHP/HAp+PTH G) also were tested on osteoblasts cultures. A negative zeta-potential at pH 7.4 was found (-14.9 mV) to PTH 1-34. The Langmuir isotherm of DPPC showed an increase of the minimum area occupied per lipid molecule after the PTH injection into the water subphase (50 ?L of 0.5 mg/mL solution) by 10.97 Å2, which could be due to the insertion of PTH in this film. The DHP minimum area changed by 2.3 Å2, which is not statistically significant. The QCM analysis showed the deposit of 72.5 ng of PTH on DPPC film, and 29.3 ng of PTH on DHP film for each 25 ?g of PTH injected into the Langmuir trough. The cell viability and matrix mineralization of osteoblasts cultures grown on DHP/Ca+PTH, and DPPC/Ca+PTH coatings decreased when compared to clean Ti. DHP/HAp+PTH S and DHP/HAp+PTH G coatings proved to be as efficient as Ti DHP/HAp to stimulate the biomineralization process. But DHP/HAp+PTH G increased the osteoblast viabilitiy and formation of mineralized matrix when compared to Ti DHP/HAp. This is an innovative coating that sets the precedent for the use of the drip technique on HAp for other hormones and drugs that act on bone tissue.

Ce travail vise à déterminer dans le cadre des sociétés s'introduisant en bourse les facteurs explicatifs de la présence d'engagements contractuels par les principaux actionnaires d'une part et leur impact sur la valeur de la firme d'autre part. Le terme " engagement contractuel " fait référence à deux mécanismes mis en place au moment de l'introduction en bourse : les engagements de conservation d'actions par les dirigeants et les pactes d'actionnaires. Notre étude porte sur un échantillon de 292 entreprises introduites en bourse entre 1996 et 2000 sur le nouveau marché et le second marché de la bourse de Paris. Nos résultats montrent que la présence et la durée des engagements de conservation d'actions des dirigeants servent à signaler la valeur de la firme lorsque l'asymétrie d'information est grande mais aussi à compenser certaines inefficiences du système de gouvernance de l'entreprise. Nous observons également un impact négatif sur la valeur de la firme des engagements de conservation des dirigeants alors que ceux concernant les sociétés de capital risque l'influence positivement. Concernant les pactes d'actionnaires, nos travaux montrent que leur mise en place est d'autant plus probable que les dirigeants anticipent une cession future de l'entreprise. Ils ont par ailleurs une influence positive sur la valeur de la firme tant qu'ils ne protègent pas les signataires d'une prise de contrôle hostile ; dans ce dernier cas l'effet sur la valeur de la firme est négatif. Finalement, nous montrons qu'il existe une réaction négative du cours de bourse autour du jour de l'expiration des engagements de conservation.

As coberturas de hidroxiapatita (HAp) são utilizadas para aumentar a osteointegração em implantes de titânio (Ti), devido à sua capacidade de promover a biomineralização para corrigir defeitos esqueléticos e craniofaciais. O objetivo desta pesquisa foi avaliar a influência dos revestimentos sobre culturas primárias de osteoblastos. Na primeira fase de estudos, desenvolvemos uma nova abordagem de revestimento baseada em filmes Langmuir-Blodgett (LB) de dihexadecilfosfato (DHP) e ácido octadecilfosfônico (OPA) depositados em discos Ti, e crescimento subsequente de cristais de HAp. Analisamos a viabilidade dos osteoblastos, a atividade da fosfatase alcalina (ALP) e a formação da matriz mineralizada por métodos colorimétricos e a morfologia das culturas por microscopia eletrônica de varredura e microscopia confocal. Os resultados revelaram que o revestimento DHP/HAp aumentou a viabilidade dos osteoblastos até 150% em comparação com o controle em todos os dias testados. O revestimento OPA/HAp promoveu a maior viabilidade ao 14 dias (190%). A atividade de ALP foi aumentada apenas pelo revestimento de DHP/HAp ao 14º dia em comparação com o controle e Ti limpo. A microscopia eletrônica de varredura e as microfotografias confocais revelaram diferenças morfológicas entre os osteoblastos cultivados em ambos os revestimentos, aumentando o seu número e o espalhamento. O revestimento de DHP/HAp aumentou a produção de nódulos biomineralizados. O ensaio de biomineralização pela técnica do Vermelho de Alizarina mostrou que o revestimento de OPA/HAp possuía uma concentração de cálcio (Ca2+) 1,88 vezes superior à cobertura de DHP/HAp. Uma vez que a literatura relata que o Ca2+ pode estimular ou inibir a atividade da ALP e, consequentemente, o processo de biomineralização, as diferenças no comportamento desses dois revestimentos podem estar relacionadas às diferenças de concentração de superfície de Ca2+. O bom desempenho do revestimento de DHP/HAp pode estar relacionado às características da composição química, adicionada à técnica de deposição LB. Na segunda fase da pesquisa, as monocamadas de Langmuir de DHP e dipalmitoil fosfatidilcolina (DPPC) foram testadas e utilizadas para incorporar o paratormônio 1-34 (PTH 1-34) (DHP/Ca+PTH e DPPC/Ca+PTH, respectivamente). Também foram testadas as ações dos revestimentos DHP/HAp com PTH em solução (DHP/HAp+PTH S) e gotejado (DHP/HAp+PTH G) em culturas de osteoblastos. Um potencial zeta negativo em pH 7,4 foi encontrado (-14,9 mV) para o PTH 1-34. A isoterma de DPPC mostrou um aumento da área mínima ocupada por molécula lipídica após a injeção de PTH na subfase de água (50 ?L de solução 0,5 mg/mL) em 10,97 Å2, o que pode ser devido à inserção de PTH neste filme. A área mínima de DHP foi alterada em 2,3 Å2, o que não é estatisticamente significativo. A análise de QCM mostrou um depósito de 72,5 ng de PTH em filme de DPPC e 29,3 ng de PTH em filme de DHP para cada 25 ?g de PTH injetado na cuba de Langmuir. A viabilidade celular e a formação da matriz mineralizada de culturas de osteoblastos crescidas em DHP/Ca+PTH e revestimentos DPPC/Ca+PTH diminuíram quando comparadas com Ti limpo. Os revestimentos DHP/HAp+PTH S e DHP/HAp+PTH G mostraram ser tão eficientes quanto o Ti DHP/HAp para estimular o processo de biomineralização. Mas a cobertura de DHP/HAp+PTH G aumentou a viabilidade dos osteoblastos e a formação de matriz mineralizada quando comparada com Ti DHP/HAp. Esta é uma cobertura inovadora que abre precedentes para o uso da técnica de gotejamento em HAp para outros hormônios e drogas que agem sobre o tecido ósseo. / Due to their ability to promote biomineralization, Hydroxyapatite (HAp) coatings are used to increase the osteointegration in titanium (Ti) implants, in order to correct skeletal and craniofacial defects. The objective of the research was to evaluate the influence of the coatings on osteoblasts primary cultures. In the first phase of the research we developed a new coating approach based on Langmuir-Blodgett (LB) films of dihexadecyl phosphate (DHP) and octadecylphosphonic acid (OPA) deposited on Ti discs and subsequent growth of HAp crystals. We analyzed the osteoblast viability, alkaline phosphatase (ALP) activity and mineralized matrix formation by colorimetric methods, and the morphology of the cultures by scanning electron microscopy and confocal micrographies. The results revealed that the DHP/HAp coating increased osteoblast viability up to 150% compared to the control at all days tested. The OPA/HAp coating promoted the highest viability on the 14th day (190%). The ALP activity was enhanced only by the DHP/HAp coating on the 14th day compared to control, and clean Ti. To explore the morphology of the cells, the scanning electron microscopy and confocal micrographies were obtained, and revealed morphological differences between osteoblasts grown on both coated Ti compared to clean Ti. Both coatings increased the number and spreading of osteoblasts, while the DHP/HAp coating enhanced the production of biomineralized nodules. The Alizarin Red assay showed that OPA/HAp coating has 1.88 times higher calcium (Ca2+) concentration than DHP/HAp. The same test confirmed the increase of mineralization only by DHP/HAp coating compared to clean Ti. Since literature reports that Ca2+ can stimulate or inhibit the ALP activity and consequently, the biomineralization process, the differences on the behavior of these two coatings could be related to the Ca2+ surface concentration differences. The good performance of the DHP/HAp coating can be explained due to the characteristics of the chemical composition, added to the LB deposition technique. In the second phase of the research, Langmuir monolayers of DHP and dipalmitoyl phosphatidylcholine (DPPC) was tested and used to incorporate 1-34 parathyroid hormone (PTH 1-34) (DHP/Ca+PTH, and DPPC/Ca+PTH, respectively). DHP/HAp coatings with PTH in solution (DHP/HAp+PTH S), and dropped (DHP/HAp+PTH G) also were tested on osteoblasts cultures. A negative zeta-potential at pH 7.4 was found (-14.9 mV) to PTH 1-34. The Langmuir isotherm of DPPC showed an increase of the minimum area occupied per lipid molecule after the PTH injection into the water subphase (50 ?L of 0.5 mg/mL solution) by 10.97 Å2, which could be due to the insertion of PTH in this film. The DHP minimum area changed by 2.3 Å2, which is not statistically significant. The QCM analysis showed the deposit of 72.5 ng of PTH on DPPC film, and 29.3 ng of PTH on DHP film for each 25 ?g of PTH injected into the Langmuir trough. The cell viability and matrix mineralization of osteoblasts cultures grown on DHP/Ca+PTH, and DPPC/Ca+PTH coatings decreased when compared to clean Ti. DHP/HAp+PTH S and DHP/HAp+PTH G coatings proved to be as efficient as Ti DHP/HAp to stimulate the biomineralization process. But DHP/HAp+PTH G increased the osteoblast viabilitiy and formation of mineralized matrix when compared to Ti DHP/HAp. This is an innovative coating that sets the precedent for the use of the drip technique on HAp for other hormones and drugs that act on bone tissue.

Cette thèse vise à analyser les aspects juridiques du rôle joué par les acteurs ayant une stratégie actionariale de court-terme (hedge funds,...) dans le cadre des offres publiques d'acquisition. Outre l'identification de ces acteurs et la description des méthodes employées, il s'agit aussi de s'interroger sur les moyens à disposition de la société cible pour se défendre et de se demander si des évolutions législatives ne seraient pas nécessaires.