Search

Obstructive sleep apnoea syndrome (OSAS) is a common clinical condition in which the throat narrows or collapses repeatedly during sleep, causing obstructive sleep apnoea events. This disorder is present in the paediatric population with a prevalence estimated between 1.2% and 5.8%. Down Syndrome (DS) is the most common chromosomal alteration associated with mental disability and characterised by other clinical manifestations, and its incidence is estimated at 1/800 births worldwide. Most of the craniofacial features typical of DS represent a risk factor for the development of OSAS. Routine screening has been recommended in some countries but it is still not a standard practice. The aim of this study is the Italian linguistic validation of a questionnaire for the diagnosis of OSAS in children with Down Syndrome.After careful review of the existing scientific literature, a specific questionnaire was selected for the diagnosis of OSAS in children with DS. The questionnaire was then translated into Italian and administered to 111 parents of children with Down syndrome, for online completion. The last part of the questionnaire was dedicated to the comprehension of the questionnaire itself, with a specific focus on its clarity, accuracy and difficulty in completing it.The positive feedback registered in the comprehension part of the questionnaire, certified the good quality of the Italian translation and confirmed the questionnaire as a useful screening method to identify the comorbidity of OSAS and DS.

This paper presents a class of fully elastomeric capacitive sensors that can be employed to measure the bending angle of flexible structures. Two possible sensing architectures are proposed here, which are obtained by similar manufacturing processes. The first solution is based on a parallel plate deformable capacitor featuring two compliant electrodes separated by a dielectric silicone membrane. The second design is based on interdigitated electrodes placed on the same side of a silicone membrane. Both types of sensors are intended to be coupled with a bending structure that, during its deformation, induces a capacitance change correlated with the value of the bending angle. The operating principle is presented and a possible simplified modeling approach is identified for both the architectures. Additionally, a simple and repeatable manufacturing process is implemented. This made it possible to realize multiple specimens of the two sensor topologies that have been tested through an experimental campaign conducted on a dedicated testbench for bending angle measurement. The results of these tests are reported and elaborated, and the two sensing strategies are compared and discussed.

Data from a direct numerical simulation for channel flow at a friction Reynolds number of 1000 are analysed to derive statistical properties that offer insight into the mechanisms by which large-scale structures in the log-law region affect the small-scale turbulence field close to the wall and the statistical skin-friction properties. The data comprise full-volume velocity fields at 150 time levels separated by 50 wall-scaled viscous time units. The scales are separated into wavelength bands by means of the ‘empirical mode decomposition’, of which the two lowest modes are considered to represent the small scales and three upper modes to represent the large scales. Joint and conditional probability density functions are then derived for various scale-specific statistics, with particular emphasis placed on the streamwise and shear stresses conditional on the large-scale fluctuations of the skin friction, generally referred to as ‘footprinting’. Statistics for the small-scale stresses, conditional on the footprints, allow the amplification and attenuation of the small-scale skin friction, generally referred to as ‘modulation’, to be quantified in dependence on the footprints. The analysis leads to the conclusion that modulation does not reflect a direct interaction between small scales and large scales, but arises from variations in shear-induced production that arise from corresponding changes in the conditional velocity profile. This causal relationship also explains the wall-normal change in sign in the correlation between large scales and small scales at a wall-scaled wall distance of approximately 100. The effects of different scales on the skin friction are investigated by means of two identities that describe the relationship between the shear-stress components and the skin friction, one identity based on integral momentum and the other on energy production/dissipation. The two identities yield significant differences in the balance of scale-specific contributions, and the origins of these differences are discussed.

Backgroundmost licensed antiviral drugs are nucleoside analogs. A recent research focuses on blocking a virus from entering the cells in the viral cell adsorption/entry stage. In this entry mechanism the glycans present on the viral surface play a fundamental role. Homochiral L-peptides acting this fusion mechanism have shown some inhibition of viral infection. Peptides with regularly alternating enantiomeric sequence (L,D-peptides) can assume structures, which are not accessible to the corresponding homochiral molecules. Further, L,D-peptides are less sensitive to the enzymatic digestion.Aimin silicodesign a L,D-peptide with a high affinity for the viral surface glycans, and consequently able to interfere with its fusion mechanism.Methodsa 3α,6α-Mannopentaose (3-6MP) molecule was used to simulate a viral surface glycan. Molecular Dynamics (MD) simulations of 3-6MP and D,L-peptide in water are performed using the force field AMBER12-GLYCAM06i. The binding constant was evaluated from trajectories. The D,L-peptide molecule was modified over the sequence, the length, the terminals and finally glycosylated to attain a very high binding constant value for 3-6MP.In addition, the specific interaction between T lymphocyte CD4 glycoprotein and HIV envelope gp120 glycoprotein was studied through MD simulations between a D,L-peptide, bounded to a typical CD4 glycan, and a highly conserved HIV gp120 glycan.Resultsin the case of interaction with 3-6MP molecule, the very effective molecule obtained was H-D-Trp-L-Pro-D-Asn-L-Pro-D-Trp-L-Pro-D-Asn-L-Pro-OH where the Asn residues in position 3 and 7 are glycosylated with alpha-D-Mannopyranosyl-(1->3)-[alpha-D-mannopyranosyl-(1->6)]-alpha-D-mannopyranosyl-(1->4)-N-acetyl-beta-D-glucopyranosyl-(1->4)-N-acetyl-beta-D-glucopyranosyl-1-OH.In the case of interaction with HIV envelope, the very effective molecule obtained, able to antagonize the CD4 glycoprotein, was H-D-Trp-L-Pro-D-Asn-L-Pro-D-Trp-L-Pro-D-Asn-L-Pro-OH where the Asn residue in position 3 is glycosylated with alpha-D-galactopyranosyl-(1->4)-N-acetyl-beta-D-glucopyranosyl-(1->2)-alpha-D-Mannopyranosyl-(1->3)-[alpha-D-galactopyranosyl-(1->4)-N-acetyl-beta-D-glucopyranosyl-(1->2)-alpha-D-Mannopyranosyl-(1->6)]-beta-D-mannopyranosyl-(1->4)-N-acetyl-beta-D-glucopyranosyl-(1->4)-N-acetyl-beta-D-glucopyranosyl-1-OHConclusionthese glycosylated D,L-peptide molecules are very promising representatives of a new class of antiviral agents.

Made available in DSpace on 2018-08-27T13:37:21Z (GMT). No. of bitstreams: 1 tese_12502_Tese - Lidiane Pignaton Agostini.pdf: 2963143 bytes, checksum: 76cc790c5543c25d309bc0feced39101 (MD5) Previous issue date: 2018-06-27 O Glifosato [N-(fosfonometil)glicina] é um herbicida pós-emergente, não seletivo e sistêmico. No processo de criação das formulações comerciais de herbicidas a base de glifosato (GBHs, do inglês glyphosate-based herbicides), como o Roundup®, são adicionados surfactantes com o intuito de aumentar a eficiência do composto base. A rota prioritária de degradação do glifosato por micro-organismos no solo resulta na formação do ácido aminometilfosfônico (AMPA). As respostas moleculares ao glifosato têm sido extensivamente estudadas em espécies de plantas e em alguns vertebrados. Em humanos, apesar dos estudos até agora realizados, não se conhece exatamente quais os riscos e mecanismos de atuação que explicariam a toxicidade ao glifosato relatada em alguns experimentos. Sendo assim, a hipótese dessa tese é de que a exposição rápida ao Roundup® e ao AMPA leva à alterações de expressão gênica em importantes processos celulares. Dessa forma, o objetivo desse trabalho é identificar genes diferencialmente expressos (DEGs, do inglês differentially expressed genes) em células mononucleares do sangue periférico (PBMCs, do inglês, peripheral blood mononuclear cells) humano submetidas à exposição rápida com herbicida à base de glifosato (Roundup®) e AMPA. O teste de MTT [3(4,5-dimetiltiazol-2-il)-2,5-difeniltetrazólio brometo], realizado em triplicatas, foi utilizado para avaliar a viabilidade celular e para a escolha das condições de tratamento utilizadas na técnica de microarray (GeneChip® Human Transcriptome Array 2.0, Affymetrix). As condições analisadas foram controle (3 chips), AMPA (10 mM; 3 chips) e Roundup® (0,05%; 2 chips), expostos durante 3 horas. Utilizando um valor de p

Direct numerical simulation data for channel flow at a friction Reynolds number of 4200, generated by Lozano-Durán and Jiménez [J. Fluid Mech. 759, 432 (2014)], are used to examine the properties of near-wall turbulence within subranges of eddy-length scale. Attention is primarily focused on the intermediate layer (mesolayer) covering the logarithmic velocity region within the range of wall-scaled wall-normal distance of 80–1500. The examination is based on a number of statistical properties, including premultiplied and compensated spectra, the premultiplied derivative of the second-order structure function, and three scalar parameters that characterize the anisotropic or isotropic state of the various length-scale subranges. This analysis leads to the delineation of three regions within the map of wall-normal-wise premultiplied spectra, each characterized by distinct turbulence properties. A question of particular interest is whether the Townsend-Perry attached-eddy hypothesis (AEH) can be shown to be valid across the entire mesolayer, in contrast to the usual focus on the outer portion of the logarithmic-velocity layer at high Reynolds numbers, which is populated with very-large-scale motions. This question is addressed by reference to properties in the premultiplied scalewise derivative of the second-order structure function (PMDS2) and joint probability density functions of streamwise-velocity fluctuations and their streamwise and spanwise derivatives. This examination provides evidence, based primarily on the existence of a plateau region in the PMDS2, for the qualified validity of the AEH right down the lower limit of the logarithmic velocity range.

A direct-numerical-simulation-based study is presented, which focuses on the response of near-wall turbulence and skin friction to the imposition of an oscillatory spanwise wall motion in channel flow. One point of contrast to earlier studies is the relatively high Reynolds number of the flow, namely Reτ=1000 in the unforced baseline flow. Another is the focus on transients in the drag that are in the form of moderate oscillatory variations in the skin friction and near-wall turbulence around the low-drag state at a sub-optimal actuation period. These conditions allow phase-averaged statistics to be extracted, during the periodic drag decrease and rise, that shed light on the interaction between turbulence and the unsteady Stokes strain. Results are presented for, among others, the phase-averaged second moments of stochastic fluctuations and their budgets, enstrophy components and joint probability density functions. The study identifies velocity skewness – the wall-normal derivative of the angle of the velocity vector – as playing a significant role in the streak-damping process during the drag-reduction phase. Furthermore, the phase-wise asymmetry in the skewness is identified as the source of a distinctive hysteresis in all properties, wherein the drag decrease progresses over a longer proportion of the actuation cycle than the drag increase. This feature, coupled with the fact that the streak-generation time scale limits the ability of the streaks to re-establish themselves during the low-skewness phase when the actuation period is sufficiently short, is proposed to drive the drag-reduction process. The observations in the study thus augment a previously identified mechanism proposed by two of the present authors, in which the drag-reduction process was linked to the rate of change in the Stokes strain in the upper region of the viscous sublayer where the streaks are strongest. Furthermore, an examination of the stochastic-stress budgets and the enstrophy lead to conclusions contrasting with those recently proposed by other authors, according to which the drag-reduction process is linked to increases in enstrophy and turbulence-energy dissipation. It is shown, both for the transient drag-reduction phase and the periodic drag fluctuations around the low-drag state, that the drag decrease/increase phases are correlated with decreases/increases in both enstrophy and dissipation.

Made available in DSpace on 2016-08-29T15:34:33Z (GMT). No. of bitstreams: 1 tese_7466_Dissertação_Lidiane Pignaton Agostini.pdf: 1793965 bytes, checksum: f9c70469168f0ae9775396a6fab642f2 (MD5) Previous issue date: 2014-02-26 O carcinoma epidermóide de cabeça e pescoço (CECP) é uma causa significativa de morbidade e mortalidade no mundo e está relacionado principalmente com os hábitos etilistas e tabagistas, mas fatores genéticos também estão relacionados. Dependendo do estadiamento do tumor, o tratamento do CECP pode ser multimodal. A radioterapia é um dos tratamentos mais realizados, visto que atua localmente sobre o tumor. Porém, o resultado ao tratamento varia entre os pacientes, de acordo com as características tumorais e individuais. Polimorfismos em genes relacionados ao reparo de DNA, controle do ciclo celular, apoptose e transcrição de citocinas são apontados como marcadores de prognóstico e de radiossensibilidade. Dessa forma, com o intuito de avaliar a relação entre polimorfismos nos genes ATM (rs664143 e rs1801516), TP53 (rs1042522), BCL2 (rs2279115) e TGFβ (rs1800470 e rs1800469) e o prognóstico e a resposta ao tratamento de pacientes com CECP, foi realizada a técnica de PCR-RFLP. Em pacientes com CE oral e de orofaringe submetidos à radioterapia, o genótipo ATM IVS62+60AA aumenta o risco de ocorrência de recidiva local e os alelos BCL2 -938C e TGFβ -509T aumentam a precocidade do óbito. Já em pacientes com CE oral e de orofaringe não submetidos à radioterapia, a homozigose TP53 Pro72 aumenta o risco de óbito. Em pacientes com CE de laringe irradiados, o alelo TGFβ Pro10 foi associado com o risco de ocorrência de recidiva local e óbito, além de influenciar na precocidade desses eventos. O alelo BCL2 -938C também foi relacionado com a precocidade de ocorrência de óbito nesses pacientes. Já o alelo TGFβ -509T foi correlacionado com o aumento do risco de óbito em pacientes com CE de laringe não irradiados. Assim, é possível que esses polimorfismos sejam importantes marcadores genéticos de radiossensibilidade tumoral, sendo candidatos à comporem um perfil genético preditivo de prognóstico em resposta à radioterapia.