This essay argues that Elizabeth Gaskell challenges the limiting gender roles of the Victorian era through giving her heroine, Margaret Hale in North and South, both the traditionally female qualities of virtue and selflessness and the traditionally masculine qualities of independence and action. The essay also argues that Gaskell’s heroine balances between the feminine and the masculine world as to not appear “unwomanly”, but rather subtly influencing the readers and calls for changing gender norms. Concrete examples of the heroine’s gender transgressions are put forward, but also her compliance to the traditional gender roles summed up in three roles or themes: the angel in the house, the female visitor and the refined lady. This essay also provides a didactic approach on working with North and South and the topic of Victorian gender norms in the upper secondary school. The relevance of and reasons for reading literature in school are also presented. The didactic chapter offers a concrete lesson plan on how to work with the theme of Victorian gender norms, which may develop students’ emphatic skills and also make them aware of ties between themselves and people that lived a long time ago.

Έχει περάσει περισσότερο από ένας αιώνας από τότε, που ο Χαρίλαος Τρικούπης, Πρωθυπουργός της Ελλάδας οραματίστηκε τη κατασκευή μιας γέφυρας, η οποία θα ένωνε την δυτική Πελοπόννησο με την ηπειρωτική Ελλάδα, το Ρίο με το Αντίρριο. Την εποχή εκείνη, τα τρία χιλιόμετρα θάλασσας, που μεσολαβούσαν μεταξύ των δυο πόλεων, φάνταζαν αδύνατο να γεφυρωθούν. Οι δυσκολίες ήταν πάρα πολλές και η τεχνογνωσία δεν είχε ακόμη φτάσει σε τέτοια επίπεδα, έτσι ώστε να δώσει πνοή σ’ αυτό το μεγαλόπνοο όραμα. Τελικά, στα μέσα της δεκαετίας του 90’, μια γαλλοελληνική σύμπραξη, αποτελούμενη από όμιλο εταιριών και από τις δυο χώρες, ανέλαβε τη σχεδίαση και κατασκευή της γέφυρας. Τα έργα ξεκίνησαν τον Ιούλιο του 1998 υπό την επίβλεψη και καθοδήγηση του αρχιτέκτονα Berdj Mikaelian. Η κατασκευή της γέφυρας αναμένετο να ολοκληρωθεί το χρονικό διάστημα μεταξύ Σεπτεμβρίου και Νοεμβρίου του 2004, άλλα οι εργασίες επισπεύτηκαν ένεκα των Ολυμπιακών Αγώνων, που θα λάβαιναν χώρα στην Αθήνα την ίδια χρονιά. Η γέφυρα θεωρήθηκε ως ένα θαύμα της σύγχρονης μηχανικής και όλα τα απαραίτητα μέτρα είχαν ληφθεί για την άρτια λειτουργία της. Παρ’ όλα αυτά στις 27 Ιανουαρίου του 2005, έξι μόλις μήνες μετά τα εγκαίνια, ένας κεραυνός έπληξε ένα από τα καλώδια στήριξης, τα οποία ενώνουν το κατάστρωμα της γέφυρας με τους πυλώνες. Το υψηλής περιεκτικότητας σε πολυαιθυλένιο καλώδιο τυλίχτηκε στις φλόγες με αποτέλεσμα να καταστραφεί ολοσχερώς και να καταρρεύσει στο κατάστρωμα. Όλες οι απαραίτητες ενέργειες έγιναν ταχύτατα, έτσι ώστε να αντικατασταθεί το καλώδιο και να παραδοθεί η γέφυρα και πάλι στη κυκλοφορία το συντομότερο δυνατό. Όμως πλέον ήταν φανερό ότι η αντικεραυνική προστασία της γέφυρας δεν ήταν αρκετή και αποτελεσματική. Στη συνέχεια του κειμένου θα γίνει ανάλυση του παραπάνω συμβάντος, αφού πρώτα γίνει αναφορά σε κάποιες βασικές αρχές γύρω από το φαινόμενο του κεραυνού και των συστημάτων αντικεραυνικής προστασίας. / More than a century has passed, since Charilaos Trikoupis, Prime Minister of Greece had contemplated the construction of a bridge that would connect western Peloponnese with the mainland of Greece, the city of Rion with Antirio. Back then, the three kilometers of sea water which separated the two cities, seemed impossible to be bridged. The difficulties were many and the know how had not reached that level, where it would make a great vision such as this, possible. Eventually, in the mid 90s, a greek-french collaboration, composed by a group of companies from both countries, took over the design and the building of the bridge. Construction works started in July of 1998 under the supervision and guidance of the architect Berdj Mikaelian. The construction of the bridge was expected to be completed during the period of September to November of 2004, but works were accelerated because of the Olympic games that would take place in Athens, that same year. The bridge was considered to be a miracle of modern mechanics and all the necessary measures were taken for its perfect operation. However, on January 27 of 2005, just six months after the opening of the bridge, a lightning stroke cut down one of the longest stay cables that connected the deck of the bridge to the pylons. The high density polyethylene cable was set on fire, and as a result of that the cable was completely destroyed and fell on the deck. All the necessary means were taken, in order to replace the cable and get traffic back on the bridge as soon as possible. It was obvious at that point that the lightning protection of the bridge was neither sufficient or effective enough. In the following chapters there are an analysis on the lightning incident on the bridge, after mentioning the natural phenomenon of lightning and the definition and the mail principals of the lightning protection system of a structure.

The main objective of this research is the study of the magnetization of ferromagnetic spheres in the presence of external magnetic fields. The exact analytical solutions derived in this thesis are benchmark solutions, valuable in testing the correctness and accuracy of various approximate models and numerical methods. The total scalar magnetic potential outside the spheres, related to the magnetic field intensity, is obtained by the superposition of the potentials due to all spheres and the potential corresponding to the external field. The translational addition theorems for scalar Laplacian functions are used to solve boundary value by imposing exact boundary conditions. The scalar magnetic potential inside each sphere, related to the magnetic flux density, also satisfies the Laplace equation, which is solved by imposing the boundary conditions known from the solution of the outside field. Finally, the expressions derived are used to generate numerical results of controllable accuracy for field quantities.

In order to improve the optical losses of spherical silicon solar cells, new fabrication designs were presented. The new device structures are fabricated based on integration of nanostructures into spherical silicon solar cells. These new device structures include: spherical silicon solar cells integrated with nanostructured antireflection coating layers, spherical silicon solar cells with hemispherical nanopit texturing, and cells integrated with colloidal quantum dots. Silicon spheres were characterized by means of transmission electron microscopy (TEM), single-crystal x-ray diffraction and x-ray powder diffraction to establish the crystallinity nature of the silicon spheres. Furthermore, the material properties of silicon spheres including surface morphology, microwave photoconductivity decay lifetime, and impurity elemental distributions were studied. Silicon nitride antireflection coating layers were developed and deposited onto the spherical silicon solar cells, using a PECVD system. A low temperature hydrogenation plasma technique was developed to improve the passivation quality of the spherical silicon solar cells. The spectral response of silicon spheres with and without a silicon nitride antireflection coating was studied. We have successfully developed and integrated a nanostructured antireflection coating layer into spherical silicon solar cells. The nanostructured porous layer consists of graded-size silicon nanocrystals and quantum-size Si nanoparticles embedded in an oxide matrix. This layer has been characterized by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM), Scanning tunneling TEM, energy filtered TEM, transmission electron diffraction (TED), electron energy loss spectroscopy (EELS), energy dispersive x-ray (EDX), Raman spectroscopy and photoluminescence spectroscopy (PL). We developed a novel technique of electrochemical etching for silicon surface texturing using a liquid-phase deposition of oxide mask. Using a focus ion-beam (FIB) technique, cross-sectional TEM samples were prepared to investigate the nature of texturing and the composition of the deposited mask. The hemispherical nanopit texturing was successfully integrated into spherical silicon solar cells and the etching mechanisms and the chemical reactions were discussed. CdSe colloidal quantum dots with diameter of about 2.8nm were integrated into a graded-density nanoporous layer. This structure was implemented on the emitter of the spherical silicon solar cells and the spectral response with and without incorporation of QDs was studied.

The history of women education has been structured by two powerful narratives. The first of these is the tale of the separation of the spheres and the second is the application of the cult of true womanhood to understand women place in the early 19th century. The purpose of this thesis is to examine and analyse the educational ideal for upperclass women in Sweden. By applying an unconventional source material, namely the Swedish lifestyle magazine Magasin för konst, nyheter och moder, a new narrative emerge. The previous research into the topic has mainly used the concepts of the separate spheres and the cult of true womanhood to explain the cultural paradigm that occurred to the hierarchy of genders during the early 19th century. This thesis aims to test if these concepts also can be applied on the previously mentioned source material, and still be viable. This thesis purpose that the previously named historical narratives can not be applied as strictly as it was previously believed. This paper critically reviews the level of education that Magasin för konst, nyheter och moder expected from its female readers, and hope that through this critical review a debate on the topic will emerge.

Submitted by Maria Medeiros (maria.dilva1@ufcg.edu.br) on 2018-06-29T13:12:48Z No. of bitstreams: 1 LUANNA ABÍLIO DINIZ MELQUÍADES DE MEDEIROS - TESE (PPGCEMat) 2016.pdf: 2959071 bytes, checksum: 8f8d00d965384bdfa5e696914975121c (MD5) / Made available in DSpace on 2018-06-29T13:12:48Z (GMT). No. of bitstreams: 1 LUANNA ABÍLIO DINIZ MELQUÍADES DE MEDEIROS - TESE (PPGCEMat) 2016.pdf: 2959071 bytes, checksum: 8f8d00d965384bdfa5e696914975121c (MD5) Previous issue date: 2016-02-29 / Diversos biomateriais tem sido desenvolvidos para preencher ou reconstruir defeitos ósseos, dentre esses destaca-se a quitosana por seu potencial osteoindutor. Outras substâncias que tem despertado o interesse da comunidade científica são os fitoterápicos, nesse grupo encontra-se o mastruz (Dysphania ambrosioides (L.) Mosyakin & Clemants), por apresentar capacidade de estimular e acelerar o reparo ósseo. Sendo assim, este trabalho objetivou desenvolver e avaliar esferas de quitosana/ Dysphania ambrosioides (L.) Mosyakin & Clemants para aplicação como biomaterial para regeneração óssea. Para tanto foi feita a coleta e identificação botânica da espécie vegetal, em seguida foi produzido o extrato alcoólico bruto (EAB) do qual foi realizada a caracterização fitoquímica. Feito isso, foram confeccionadas esferas, pela técnica de geleificação ionotrópica, utilizando o Tripolifosfato de sódio (TPP) como agente de reticulação e em seguida as mesmas foram lavadas com água destilada e colocadas para secagem na estufa. Após esse processo, as esferas de quitosana e quitosana com diferentes concentrações do EAB foram caracterizadas utilizando Microscopia Ótica (MO); Microscopia Eletrônica de Varredura (MEV); Espectroscopia na região do infravermelho com transformada de Fourier (FTIR); Medida do diâmetro das mesmas; ensaios de Citotoxicidade in vitro, Biodegradação enzimática in vitro e Compressão. O resultado da caracterização fitoquímica, demonstrou a presença de esteróides, saponinas e principalmente flavonóides no extrato alcóolico bruto (EAB). A MO evidenciou a formação de esferas bem delimitadas e com tendência a ficarem mais escuras a medida em que se aumentava a concentração do EAB; a MEV revelou a presença de uma superfície externa enrugada e uma superfície interna com aspecto denso devido ao processo de secagem na estufa. O estudo químico realizado através do FTIR identificou todas as bandas características típicas de cada material estudado nesta pesquisa; e nas esferas produzidas, verificou-se a interação do TPP com a quitosana. A medida do diâmetro das esferas de quitosana sem incorporação EAB (Q0) foi menor em comparação aos demais grupos: quitosana+5% de EAB (Q5), quitosana+10% de EAB (Q10) e quitosana+20% de EAB (Q20). Todas as amostras foram consideradas não citotóxicas; com relação à biodegradação, na presença de lisozima, as esferas de todos os grupos apresentaram perda de massa em todos os tempos estudados, já na solução Phosphate Buffered Saline (PBS) foi observado um ganho de massa em todos os grupos nos diversos tempos estudados. O grupo Q0 suportou maior carga compressiva e também deformou mais, antes de fraturar, quando comparado aos grupos Q5, Q10 e Q20. Desta forma pode-se concluir que a metodologia para produção de esferas foi de fácil execução, sendo por tanto reprodutível e que por meio das caracterizações realizadas observou-se que o EAB, tornou as esferas maiores, atuou como agente reticulante da quitosana, aumentando o tempo de degradação e também a carga compressiva suportada e deformação sofrida até a fratura. Dessa forma a incorporação do EAB foi favorável para utilização das esferas como possível agente osteoindutor, visto que os produtos da sua degradação podem atuar com esse propósito, sendo as esferas do grupo Q20 as mais indicadas para áreas com dimensões anatômicas reduzidas / Several biomaterials have been developed to fill in or reconstruct bone defects, among these the chitosan stands out due to its osteoinductive potential. Other substances have aroused the interest of the scientific community are the phytotherapics, in this group can be found the ‘mastruz’ (Dysphania ambrosioides (L.) Mosyakin & Clemants), for presenting the capacity of stimulating and accelerate bone repair. Thereby, this work aimed to develop and assess chitosan Dysphania ambrosioides (L.) Mosyakin & Clemants spheres for application as a biomaterial for bone regeneration. For this purpose the collection and botanical identification was carried out, and after the crude ethanolic extract (CEE) was produced, and its phytochemical characterization was performed. Having done this, spheres were made, by the ionotropic gelation method, using the Sodium tripolyphosphate (TPP) as a cross-linking agent and after, they were washed with distilled water and placed to dry in the oven. After this process, the chitosan spheres and chitosan with different concentrations of the EAB were characterized using Optical Microscopy (OM); Scanning Electron Microscopy (SEM); Fourier transformed infrared spectroscopy (FTIR); measurement of the diameter; in vitro Cytotoxicity, in vitro Enzymatic biodegradation and Compression tests. The result of the phytochemical characterization, demonstrated the presence of steroids, saponins and mainly flavonoids, in the crude ethanolic extract (CEE). The OM revealed the formation of well delimited spheres with a tendency of becoming darker as the EAB concentration increased; the SEM revealed the presence of a wrinkled external surface and an internal surface with a dense aspect due to the drying in the oven process. The chemical study performed by the FTIR identified all the bands typical characteristics of each material studied in this research; and in the produced spheres, the interaction of the TTP with the chitosan was found. The measures of the chitosan sphere’s diameters without the incorporation of the CEE (Q0) were smaller in comparison to the other groups: chitosan+5% of CEE (Q5), chitosan+10% of CEE (Q10) and chitosan+20% of CEE (Q20). All the samples were considered not cytotoxic; in relation to the biodegradation, in the presence of lysozyme, the spheres of all the groups presented mass loss at all the studied times, as for in the solution Phosphate Buffered Saline (PBS) a mass gain was observed in all the groups at the various studied moments. The Q0 group bared a greater compressive load and also deformed more, before fracturing, when compared to the Q5, Q10 and Q20 groups. This way it can be concluded that the methodology for the production of spheres was easy to carry out, therefore being reproducible and by means of the characterizations performed it was observed that CEE, made the spheres bigger, acted as a crosslinking agent of the chitosan, increasing the degradation time and also the supported compressive load and deformation suffered until the fracture. This way the incorporation of the CEE was favorable for the use of the spheres as a possible osteoinductor agent, seen as the products of their degradation may act with this purpose, being the spheres of the Q20 group the most indicated for areas with reduced anatomic dimensions.

Submitted by Maria Medeiros (maria.dilva1@ufcg.edu.br) on 2018-06-29T13:53:39Z No. of bitstreams: 1 GREYCE YANE HONORATO SAMPAIO - TESE (PPGCEMat) 206.pdf: 8427492 bytes, checksum: a008b21b874e092dc5037d0778bb1057 (MD5) / Made available in DSpace on 2018-06-29T13:53:39Z (GMT). No. of bitstreams: 1 GREYCE YANE HONORATO SAMPAIO - TESE (PPGCEMat) 206.pdf: 8427492 bytes, checksum: a008b21b874e092dc5037d0778bb1057 (MD5) Previous issue date: 2016-02-29 / Capes / A policaprolactona (PCL), utilizada como matriz biodegradável em combinação à nanohidroxiapatita (nHA), intrinsecamente bioativa, é uma alternativa promissora para a produção de matrizes tridimensionais (3D) porosas, visando a regeneração do tecido ósseo. No entanto, rotas de processamento visando otimizar a interação entre esses materiais devem ser investigadas. O objetivo deste trabalho foi desenvolver matrizes 3D de PCL/nHA estruturadas por esferas, via agregação por aquecimento a baixas temperaturas. Para isto, foram produzidas nHA por precipitação química via úmida, utilizando o Ca(NO3)2.4H2O e o (NH4)2HPO4 como precursores, conduzido à 80 °C (pH>10). Estas foram caracterizadas por difração de Raios X (DRX), espectroscopia na região no infravermelho com transformada de Fourier (FTIR) e microscopia eletrônica de transmissão (MET). A superfície das nHA foi modificada com ácido esteárico (AE), verificada pelos resultados de FTIR, MET e monitoramento de estabilidade. Esferas de PCL e PCL/nHA foram produzidas pelo método de emulsão simples com evaporação do solvente, o diclorometano, em 02 etapas, para obtenção de diâmetros entre 10-150 µm e maiores que 800 µm. Foram investigadas as influências da concentração de PCL, da adição de nHA com e sem AE, da concentração de álcool polivinílico e da velocidade de emulsificação. O material foi caracterizado por DRX, FTIR, microscopia eletrônica de varredura (MEV), calorimetria exploratória diferencial (DSC) e análise termogravimétrica (ATG), sendo calculado também o rendimento. Matrizes 3D porosas de PCL e de PCL/nHA foram produzidas e analisadas por microscopia ótica (MO), MEV e ensaios in vitro de bioatividade e de adesão celular. nHA deficientes em cálcio, em formato de haste (~47 nm x ~8 nm) e com superfície específica de 90,1 m2/g, foram obtidas. Esferas de PCL e PCL/nHA foram produzidas com diâmetros entre 2-3000 µm, densas ou porosas, contendo nHA distribuídas interna e externamente. Matrizes 3D foram obtidas a partir da agregação das esferas produzidas, estruturadas entre si a partir da formação de pescoços entre esferas adjacentes, com hierarquia de poros medindo até 1500 µm. As matrizes apresentaram capacidade bioativa e satisfatória adesão e desenvolvimento celular. Os resultados sugerem a aplicação vantajosa desses dispositivos para a regeneração de tecidos ósseos. / Polycaprolactone (PCL) have been largely used as a biodegradable matrix. This polymer in a combination with bioactive calcium deficient nanohydroxyapatite (CD-nHA) represent promising materials to be applied for bone tissue engineering. Nevertheless, processing routes to optimize the interaction between these materials should be investigated. Thus, the aim of this work was to develop PCL/nHA spherebased scaffolds structured by sinterization at low temperatures. For this, nHA were produced by wet chemical precipitation method, using the precursors Ca(NO3)2.4H2O and (NH4)2HPO4, conducted at 80 °C (pH>10). The powder was characterized by Xray diffraction (XRD), fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). nHA surface was modified with stearic acid (SA), verified with FTIR and TEM analysis and stability control in dichloromethane (DCM). PCL and PCL/nHA spheres were produced by oil-in-water and solid-in-oil-in-water emulsion solvent evaporation method. This production occurred in 02 steps, to obtain diameters ranging 10-150 µm and higher than 800 µm. The follow parameters were investigated: PCL concentration, nHA content with and without AE, polyvinyl alcohol concentration (stabilizing agent) and emulsification stirring. The material was characterized by DRX, FTIR, scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and thermogravimetric analysis (ATG), and the percent yield was calculated. PCL and PCL/nHA porous scaffolds were produced and characterized by SEM, optical microscopy (MO), and in vitro bioactivity and cell adhesion assays. Calcium deficient nHA, shaped as rods (~47 nm x ~8 nm), with a specific surface of 90,1 m2/g was obtained. PCL and PCL/nHA spheres were produced with diameters ranging 2-3000 µm, dense or porous, containing nHA effectively distributed internally and at the surface. Scaffolds were successfully obtained by sintering the spheres at low temperatures. It was observed connections shaped as necks in adjacent spheres, and a hierarchical porous architecture with pores measuring up to 1500 µm. It was demonstrated satisfactory bioactivities capacity, cellular adhesion, and cellular development. Our results suggested the advantageous applicability of these scaffolds to bone tissue regeneration.

O câncer é um problema de saúde pública mundial, apresentando acréscimo na sua incidência a cada ano. O seu processo de evolução ainda não foi completamente desvendado, dificultando a elaboração de terapias adequadas. Na busca por um melhor prognóstico, pesquisas recentes têm discutido o papel das citocinas inflamatórias, do nicho perivascular e das células-tronco nos mecanismos de desenvolvimento e manutenção dos tumores malignos. Os tumores de glândula salivar representam uma pequena porcentagem das patologias malignas da região de cabeça e pescoço, podendo ocorrer em adultos e em crianças. O diagnóstico dificilmente é precoce e a taxa de sobrevida é extremamente baixa comparada aos demais tumores da região. Assim, este estudo teve como objetivo estudar as células provenientes dos tumores de glândula salivar do tipo adenoide cístico (CAC) e adenocarcinoma NOS (AdNOS) quanto ao seu perfil imunofenotípico, quanto à existência ou não de células-tronco tumorais nessa população, bem como investigar possíveis modificações na ativação de STAT3, Akt e ERK (moléculas envolvidas em vias de sinalização de manutenção do tumor), quando em contato com fatores secretados por células endoteliais. Foram coletados 5 CACs e 4 AdNOS, no Hospital da Universidade de Michigan (Ann Arbor, MI, EUA), durante 2010 e 2012. As células foram isoladas e caracterizadas em citometria de fluxo em P0 e P7, demonstrando um perfil de células CD44+ALDH+Lin- variando de 0,33 a 3,19% e 0,36 a 2,00%, respectivamente, entre 5 linhagens avaliadas. Na avaliação por western blotting, a e-caderina, o Snail e a actina de músculo liso foram ausentes em todos os tipos tumorais, enquanto que a citoqueratina 20 (Ck20) foi presente apenas nos AdNOS. Comparando os tumores com suas metástases, a presença de Ck20, p63 e β-catenina foi semelhante, enquanto que citoqueratina 7, a vimentina e o Bmi-1 foram maiores nas metástases. Tanto os AdNOS quanto CACs apresentaram receptores para IL-6, IL-8 e EGF. Foi observado que mediadores solúveis liberados pelas células endoteliais foram capazes de fosforilar STAT3, Akt e ERK em todas as células salivares estudadas, no entanto, a proteína recombinante humana IL-6, isoladamente, não foi capaz de ativar Akt. Orosferas foram geradas em todos os tipos tumorais, demonstrando o potencial de auto-renovação celular. Um maior número de esferas foi observado nas células metastáticas em relação às primárias. Células CD44+ALDH+, comparadas com CD44-ALDH-, geraram mais esferas, quando plaqueadas em alta densidade (5.000 células). No entanto, o inverso foi encontrado, quando uma única célula foi utilizada para o ensaio (p>0,05). Devido à dificuldade de obtenção e manipulação de células de tumores de glândula salivar, ainda há muito que se investigar mecanisticamente. Considerando a fosforilação de STAT3 na presença de IL-6, semelhante ao verificado em outros tumores, o uso de anticorpos contra IL-6, talvez sejam uma opção no futuro. / Cancer is a public health problem worldwide, with an increase in incidence every year. The process of its evolution is still not completely understood, hindering the development of appropriate therapies. In the search for a better prognosis, recent reports have discussed the role of inflammatory cytokines, perivascular niche and stem cells in the mechanisms of development and maintenance of malignant tumors. The salivary gland tumors represent a small percentage of malignancies of the head and neck and can occur in both adults and children. Early diagnosis is difficult and the survival rate is extremely low compared to other tumors in the same region. Thus, this study aimed to study cells from the adenoid cystic carcinoma (ACC) and adenocarcinoma NOS (AdNOS) tumors of salivary gland regarding its immunophenotypic profile and the existence or absence of tumor stem cells in this population, as well as investigate possible changes in the activation of STAT3, Akt and ERK (molecules involved in signaling pathways of tumor maintenance), when exposed to factors secreted by endothelial cells. ACCs (n=5) and AdNOS (n=4) were collected at the Hospital of the University of Michigan (Ann Arbor, MI, USA), during 2010 to 2012. Cells were isolated and characterized by flow cytometry at P0 and P7, showing a profile of ALDH+CD44+Lin- ranging from 0.33% to 3.19% and 0.36% and 2.00%, respectively, between 5 cell lines evaluated. In the protein profile, e-cadherin, Snail and SMA were absent in all tumor types. Ck20 was present only in AdNOS. Comparing primary tumors and their metastases, the presence of Ck20, and p63 β-catenin was similar, while Ck7, vimentin and Bmi-1 were higher in metastases. Both AdNOS as ACCs had receptors for IL-6, IL-8 and EGF. It was observed that soluble mediators released by endothelial cells were able to activate STAT3, Akt and ERK phosphorylation in all cells studied. However, recombinant human IL-6 alone was not able to activate Akt. Orospheres were generated in all tumor types, indicating the potential for cellular self-renewal. Highest number of spheres was observed in metastatic cells compared to primary. ALDH+CD44+ cells compared to ALDH-CD44- generated more spheres when plated in high density (5,000 cells), however, the opposite was found when one single cell seed was evaluated (p> 0.05). There is doubt if these cell markers would be consider for a stem cell model in salivary tumors. Due to the difficulty of obtaining and manipulating salivary gland tumor cells, there is still much to investigate mechanistically. As the phosphorylation of STAT3, in the presence of IL-6, was similar to that observed in other tumors, the use of antibodies against IL-6, may be an option in the future.

Exact solutions to Einstein's field equations in the presence of matter are presented. A one parameter family of interior solutions for a static fluid is discussed. It is shown that these solutions can be joined to the Schwarzschild exterior, and hence represent fluid spheres of finite radius. Contained within this family is a set of solutions which are gaseous spheres defined by the vanishing of the density at the surface. One such solution yields an analytic expression which corresponds to the asymptotic numerical solution of Oppenheimer and Volkoff for the degenerate neutron gas. These gaseous spheres have ratios of specific heats that lie between one and two in the vicinity of the origin, increasing outward, but remaining less than the velocity of light throughout.

O câncer é um problema de saúde pública mundial, apresentando acréscimo na sua incidência a cada ano. O seu processo de evolução ainda não foi completamente desvendado, dificultando a elaboração de terapias adequadas. Na busca por um melhor prognóstico, pesquisas recentes têm discutido o papel das citocinas inflamatórias, do nicho perivascular e das células-tronco nos mecanismos de desenvolvimento e manutenção dos tumores malignos. Os tumores de glândula salivar representam uma pequena porcentagem das patologias malignas da região de cabeça e pescoço, podendo ocorrer em adultos e em crianças. O diagnóstico dificilmente é precoce e a taxa de sobrevida é extremamente baixa comparada aos demais tumores da região. Assim, este estudo teve como objetivo estudar as células provenientes dos tumores de glândula salivar do tipo adenoide cístico (CAC) e adenocarcinoma NOS (AdNOS) quanto ao seu perfil imunofenotípico, quanto à existência ou não de células-tronco tumorais nessa população, bem como investigar possíveis modificações na ativação de STAT3, Akt e ERK (moléculas envolvidas em vias de sinalização de manutenção do tumor), quando em contato com fatores secretados por células endoteliais. Foram coletados 5 CACs e 4 AdNOS, no Hospital da Universidade de Michigan (Ann Arbor, MI, EUA), durante 2010 e 2012. As células foram isoladas e caracterizadas em citometria de fluxo em P0 e P7, demonstrando um perfil de células CD44+ALDH+Lin- variando de 0,33 a 3,19% e 0,36 a 2,00%, respectivamente, entre 5 linhagens avaliadas. Na avaliação por western blotting, a e-caderina, o Snail e a actina de músculo liso foram ausentes em todos os tipos tumorais, enquanto que a citoqueratina 20 (Ck20) foi presente apenas nos AdNOS. Comparando os tumores com suas metástases, a presença de Ck20, p63 e β-catenina foi semelhante, enquanto que citoqueratina 7, a vimentina e o Bmi-1 foram maiores nas metástases. Tanto os AdNOS quanto CACs apresentaram receptores para IL-6, IL-8 e EGF. Foi observado que mediadores solúveis liberados pelas células endoteliais foram capazes de fosforilar STAT3, Akt e ERK em todas as células salivares estudadas, no entanto, a proteína recombinante humana IL-6, isoladamente, não foi capaz de ativar Akt. Orosferas foram geradas em todos os tipos tumorais, demonstrando o potencial de auto-renovação celular. Um maior número de esferas foi observado nas células metastáticas em relação às primárias. Células CD44+ALDH+, comparadas com CD44-ALDH-, geraram mais esferas, quando plaqueadas em alta densidade (5.000 células). No entanto, o inverso foi encontrado, quando uma única célula foi utilizada para o ensaio (p>0,05). Devido à dificuldade de obtenção e manipulação de células de tumores de glândula salivar, ainda há muito que se investigar mecanisticamente. Considerando a fosforilação de STAT3 na presença de IL-6, semelhante ao verificado em outros tumores, o uso de anticorpos contra IL-6, talvez sejam uma opção no futuro. / Cancer is a public health problem worldwide, with an increase in incidence every year. The process of its evolution is still not completely understood, hindering the development of appropriate therapies. In the search for a better prognosis, recent reports have discussed the role of inflammatory cytokines, perivascular niche and stem cells in the mechanisms of development and maintenance of malignant tumors. The salivary gland tumors represent a small percentage of malignancies of the head and neck and can occur in both adults and children. Early diagnosis is difficult and the survival rate is extremely low compared to other tumors in the same region. Thus, this study aimed to study cells from the adenoid cystic carcinoma (ACC) and adenocarcinoma NOS (AdNOS) tumors of salivary gland regarding its immunophenotypic profile and the existence or absence of tumor stem cells in this population, as well as investigate possible changes in the activation of STAT3, Akt and ERK (molecules involved in signaling pathways of tumor maintenance), when exposed to factors secreted by endothelial cells. ACCs (n=5) and AdNOS (n=4) were collected at the Hospital of the University of Michigan (Ann Arbor, MI, USA), during 2010 to 2012. Cells were isolated and characterized by flow cytometry at P0 and P7, showing a profile of ALDH+CD44+Lin- ranging from 0.33% to 3.19% and 0.36% and 2.00%, respectively, between 5 cell lines evaluated. In the protein profile, e-cadherin, Snail and SMA were absent in all tumor types. Ck20 was present only in AdNOS. Comparing primary tumors and their metastases, the presence of Ck20, and p63 β-catenin was similar, while Ck7, vimentin and Bmi-1 were higher in metastases. Both AdNOS as ACCs had receptors for IL-6, IL-8 and EGF. It was observed that soluble mediators released by endothelial cells were able to activate STAT3, Akt and ERK phosphorylation in all cells studied. However, recombinant human IL-6 alone was not able to activate Akt. Orospheres were generated in all tumor types, indicating the potential for cellular self-renewal. Highest number of spheres was observed in metastatic cells compared to primary. ALDH+CD44+ cells compared to ALDH-CD44- generated more spheres when plated in high density (5,000 cells), however, the opposite was found when one single cell seed was evaluated (p> 0.05). There is doubt if these cell markers would be consider for a stem cell model in salivary tumors. Due to the difficulty of obtaining and manipulating salivary gland tumor cells, there is still much to investigate mechanistically. As the phosphorylation of STAT3, in the presence of IL-6, was similar to that observed in other tumors, the use of antibodies against IL-6, may be an option in the future.