957 resultados para prisme minimal
Minimal intervention dentistry and older patients part 2: minimally invasive operative interventions
Resumo:
As described in the first paper of this two part series, the expansion of our older population and the concomitant reduction in levels of edentulism will result in an increase in the number of patients presenting in general practice with complex restorative challenges. The application of the concepts of minimal intervention dentistry and minimally invasive operative techniques may offer a powerful armamentarium to the general dentist to provide ethical and conservative treatment to older patients.
Clinical Relevance: When it is unavoidable, operative intervention should be as minimally invasive as practicable in older patients to preserve the longevity of their natural dentition.
Resumo:
Ten million people in the UK today are aged over 65. The latest projections estimate that there will be 5 1/2 million more people aged 65 and older in the next 20 years. This projected pattern of population ageing will have profound consequences for dentistry. Minimal intervention dentistry (MID) is a modern evidence-based approach to caries management in dentate patients that uses the 'medical model' whereby disease is controlled by the 'oral physician'. This approach offers considerable benefits over conventional dentistry for older patients. It encourages patients to be responsible for their oral health through the provision of both knowledge and motivation. MID encompasses risk assessment for dental disease, early detection and control of disease processes, and minimally invasive treatment.
Clinical Relevance: Risk assessment tools can aid the general dental practitioner and the patient to develop a suitable caries prevention programme for that individual and reduce the need for future operative intervention.
Resumo:
Vegetables of the Apiaceae plant family such as carrots, parsnip, celery and parsley,contain in minor quantities, a group of bioactive aliphatic C17-polyacetylenes (falcarinol,falcarindiol, falcarindiol-3- acetate). Recent studies have highlighted important biologicalfunctions in vitro and in vivo (animal studies) although the beneficial effect in humannutrition attributable to an increased in polyacetylenes diet are yet to be confirmed(Lund, 1990).Carrots not only contain relatively high polyacetylene content but also form a significantpart of many countries dietary habits. Carrots are also present in some ready-to-eat foodssuch as chilled freshly prepared salads, as part of the increasingly popular minimallyprocessed foods. Whereas the effect of conventional processing (boiling, vacuum processing) on the levels of polyacetylenes has been relatively well studied, the effect of minimal mechanical operations such as “peeling”, “mechanical cutting” and “chlorine washing” remains unknown.
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In this single centre study of childhood acute lymphoblastic leukaemia (ALL) patients treated on the Medical Research Council UKALL 97/99 protocols, it was determined that minimal residual disease (MRD) detected by real time quantitative polymerase chain reaction (RQ-PCR) and 3-colour flow cytometry (FC) displayed high levels of qualitative concordance when evaluated at multiple time-points during treatment (93.38%), and a combined use of both approaches allowed a multi time-point evaluation of MRD kinetics for 90% (53/59) of the initial cohort. At diagnosis, MRD markers with sensitivity of at least 0.01% were identified by RQ-PCR detection of fusion gene transcripts, IGH/TRG rearrangements, and FC. Using a combined RQ-PCR and FC approach, the evaluation of 367 follow-up BM samples revealed that the detection of MRD >1% at Day 15 (P = 0.04), >0.01% at the end of induction (P = 0.02), >0.01% at the end of consolidation (P = 0.01), >0.01% prior to the first delayed intensification (P = 0.01), and >0.1% prior to the second delayed intensification and continued maintenance (P = 0.001) were all associated with relapse and, based on early time-points (end of induction and consolidation) a significant log-rank trend (P = 0.0091) was noted between survival curves for patients stratified into high, intermediate and low-risk MRD groups.
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Wilms' tumor gene 1 (WT1) is overexpressed in the majority (70-90%) of acute leukemias and has been identified as an independent adverse prognostic factor, a convenient minimal residual disease (MRD) marker and potential therapeutic target in acute leukemia. We examined WT1 expression patterns in childhood acute lymphoblastic leukemia (ALL), where its clinical implication remains unclear. Using a real-time quantitative PCR designed according to Europe Against Cancer Program recommendations, we evaluated WT1 expression in 125 consecutively enrolled patients with childhood ALL (106 BCP-ALL, 19 T-ALL) and compared it with physiologic WT1 expression in normal and regenerating bone marrow (BM). In childhood B-cell precursor (BCP)-ALL, we detected a wide range of WT1 levels (5 logs) with a median WT1 expression close to that of normal BM. WT1 expression in childhood T-ALL was significantly higher than in BCP-ALL (P<0.001). Patients with MLL-AF4 translocation showed high WT1 overexpression (P<0.01) compared to patients with other or no chromosomal aberrations. Older children (> or =10 years) expressed higher WT1 levels than children under 10 years of age (P<0.001), while there was no difference in WT1 expression in patients with peripheral blood leukocyte count (WBC) > or =50 x 10(9)/l and lower. Analysis of relapsed cases (14/125) indicated that an abnormal increase or decrease in WT1 expression was associated with a significantly increased risk of relapse (P=0.0006), and this prognostic impact of WT1 was independent of other main risk factors (P=0.0012). In summary, our study suggests that WT1 expression in childhood ALL is very variable and much lower than in AML or adult ALL. WT1, thus, will not be a useful marker for MRD detection in childhood ALL, however, it does represent a potential independent risk factor in childhood ALL. Interestingly, a proportion of childhood ALL patients express WT1 at levels below the normal physiological BM WT1 expression, and this reduced WT1 expression appears to be associated with a higher risk of relapse.
Resumo:
Nesta tese estamos preocupados com o problema da resistência mínima primeiro dirigida por I. Newton em seu Principia (1687): encontrar o corpo de resistência mínima que se desloca através de um médio. As partículas do médio não interagem entre si, bem como a interação das partículas com o corpo é perfeitamente elástica. Diferentes abordagens desse modelo foram feitas por vários matemáticos nos últimos 20 anos. Aqui damos uma visão geral sobre estes resultados que representa interesse independente, uma vez que os autores diferentes usam notações diferentes. Apresentamos uma solução do problema de minimização na classe de corpos de revolução geralmente não convexos e simplesmente conexos. Acontece que nessa classe existem corpos com resistência menor do que o mínimo da resistência na classe de corpos convexos de revolução. Encontramos o infimum da resistência nesta classe e construimos uma sequência regular de corpos que aproxima este infimum. Também apresentamos um corpo de resistência nula. Até agora ninguém sabia se tais corpos existem ou não, evidentemente o nosso corpo não pertence a nenhuma classe anteriormente analisado. Este corpo é não convexo e não simplesmente conexo; a forma topológica dele é um toro, parece um UFO extraterrestre. Apresentamos aqui várias famílias de tais corpos e estudamos as suas propriedades. Também apresentamos um corpo que é natural de chamar um corpo "invisíveis em uma direção", uma vez que a trajectória de cada partícula com a certa direcção coincide com a linha recta fora do invólucro convexo do corpo. ABSTRACT: In this thesis we are concerned with the problem of minimal resistance first addressed by I. Newton in his Principia (1687): find the body of minimal resistance moving through a medium. The medium particles do not mutually interact, and the interaction of particles with the body is perfectly elastic. Different approaches to that model have been tried by several mathematicians during the last 20 years. Here we give an overview of these results that represents interest in itself since all authors use different notations. We present a solution of the minimization problem in the class of generally non convex, simply connected bodies of revolution. It happens that in this class there are bodies with smaller resistance than the minimum in the class of convex bodies of revolution. We find the infimum of the resistance in this class, and construct a sequence of bodies which approximates this infimum. Also we present a body of zero resistance. Since earlier it was unknown if such bodies exists or not, evidently our body does not belong to any class previously examined. The zero resistance body found by us is non-convex and non-simply connected; topologically it is a torus, and it looks like an extraterrestrial UFO. We present here several families of such bodies and study their properties. We also present a body which is natural to call a body "invisible in one direction", since the trajectory of each particle with the given direction, outside the convex hull of the body, coincides with a straight line.
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In this thesis we consider two-dimensional (2D) convolutional codes. As happens in the one-dimensional (1D) case one of the major issues is obtaining minimal state-space realizations for these codes. It turns out that the problem of minimal realization of codes is not equivalent to the minimal realization of encoders. This is due to the fact that the same code may admit different encoders with different McMillan degrees. Here we focus on the study of minimality of the realizations of 2D convolutional codes by means of separable Roesser models. Such models can be regarded as a series connection between two 1D systems. As a first step we provide an algorithm to obtain a minimal realization of a 1D convolutional code starting from a minimal realization of an encoder of the code. Then, we restrict our study to two particular classes of 2D convolutional codes. The first class to be considered is the one of codes which admit encoders of type n 1. For these codes, minimal encoders (i.e., encoders for which a minimal realization is also minimal as a code realization) are characterized enabling the construction of minimal code realizations starting from such encoders. The second class of codes to be considered is the one constituted by what we have called composition codes. For a subclass of these codes, we propose a method to obtain minimal realizations by means of separable Roesser models.
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Ce mémoire s'intéresse aux relations de pouvoir entre les hommes et les femmes telles qu'elles s'expriment à travers les "scripts" sexuels (Gagnon) dans six oeuvres québécoises écrites après les années 2000. Deux critères déterminent le choix des oeuvres : la sphère de légitimité à laquelle elles appartiennent et le sexe des auteurs. Le premier chapitre s'intéresse à deux oeuvres légitimées écrites par des femmes : La Brèche (2002) de Marie-Sissi Labrèche et Infrarouge (2010) de Nancy Huston; le deuxième chapitre aborde deux romans légitimés écrits par des hommes : Bouche-à-bouch e [i.e. bouche] (2003) de Mauricio Segura et L'aimé (2007) d'Antonio D'Alfonso; enfin le troisième chapitre étudie, quant à lui, deux recueils de nouvelles érotiques relevant de la littérature populaire, l'un écrit par une femme, l'autre par un homme: Grande aventure et petites histoires libertines (2007) de Julie Bray et Tentations voluptueuses (2006) de Martin Lortie. Chacun des chapitres se divise en quatre parties. Dans la première partie, sont étudiés le genre des voix narratives en lien avec le sexe des auteurs. La deuxième partie s'emploie à tracer le portrait des personnages féminins et masculins principaux à l'intérieur des oeuvres. Les troisième et quatrième parties étudient plus spécifiquement les scènes sexuelles, d'abord à partir de l'analyse de l'espace et ensuite à partir [de] l'analyse des"scripts" sexuels. Nous tâchons de définir si les représentations permettent d'observer des relations justes et équitables ou dissymétriques entre les sexes, et de vérifier si les auteur¨e¨s emploient des matériaux qui tendent au traditionalisme, à la modernité ou à la postmodernité. (Boisclair et St-Martin)
Resumo:
Interest in polyethylene and polypropylene bonding has increased in the last years. However, adhesive joints with adherends which are of low surface energy and which are chemically inert present several difficulties. Generally, their high degree of chemical resistance to solvents and dissimilar solubility parameters limit the usefulness of solvent bonding as a viable assembly technique. One successful approach to adhesive bonding of these materials involves proper selection of surface pre-treatment prior to bonding. With the correct pre-treatment it is possible to glue these materials with one or more of several adhesives required by the applications involved. A second approach is the use of adhesives without surface pre-treatment, such as hot melts, high tack pressure-sensitive adhesives, solvent-based specialty adhesives and, more recently, structural acrylic adhesives as such 3M DP-8005® and Loctite 3030®. In this paper, the shear strengths of two acrylic adhesives were evaluated using the lap shear test method ASTM D3163 and the block shear test method ASTM D4501. Two different industrial polyolefins (polyethylene and polypropylene) were used for adherends. However, the focus of this study was to measure the shear strength of polyethylene joints with acrylic adhesives. The effect of abrasion was also studied. Some test specimens were manually abraded using 180 and 320 grade abrasive paper. An additional goal of this work was to examine the effect of temperature and moisture on mechanical strength of adhesive joints.
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Phosphatase and tensin homologue (PTEN) protein belongs to the family of protein tyrosine phos-phatase. Mutations on the phosphatase and tensin homologue (PTEN) protein are highly observed in diverse types of human tumors, being mostly identified on the phosphatase domain of the protein. Although PTEN is a modular protein composed by a phosphatase domain and a C2 domain for mem-brane anchoring, this work aimed at developing a minimal version of PTEN´s phosphatase domain. The minimal version (Small Domain) comprises a 28 residue peptide, with the PTEN 8-mer catalytic peptide accommodated between a α-helix and β-turn as observed in PTEN native structure. Firstly, a de novo prediction of the Small Domain´s secondary structure was carried out by molecular modeling tools. The stability of the predicted structures were then evaluated by Molecular Dynamics. Automated molecular docking of PTEN natural substrate PIP3, its analogue (Inositol) and a PTEN inhibitor (L-tar-tare) were performed with the modeled structure, and PTEN used as a positive control. The gene en-coding for Small Domain was designed and cloned into an expression vector at N-terminal of Green Fluorescence Protein (GFP) encoding gene. The fusion protein was then expressed in Escherichia coli cells. Different expression conditions have been explored for the production of the fusion protein to minimize the formation of inclusion bodies.
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Operative treatment of coronoid fracture often requires a large dissection of soft tissue, resulting in elbow stiffness and functional limitation. The authors present a minimal invasive, safe technique, useful in the case of isolated coronoid fracture associated with elbow dislocation. This technique does not require soft tissue dissection and allows an early unlimited resumption of sports activities.
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Immunotherapy, especially therapeutic vaccination, has a great deal of potential in the treatment of cancer and certain infectious diseases such as HIV (Allison et al., 2006; Fauci et al., 2008; Feldmann and Steinman, 2005). Numerous vaccine candidates have been tested in patients with a variety of tumor types and chronic viral diseases. Often, the best way to assess the clinical potential of these vaccines is to monitor the induced T cell response, and yet there are currently no standards for reporting these results. This letter is an effort to address this problem.
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Our objective is to develop a diffusion Monte Carlo (DMC) algorithm to estimate the exact expectation values, ($o|^|^o), of multiplicative operators, such as polarizabilities and high-order hyperpolarizabilities, for isolated atoms and molecules. The existing forward-walking pure diffusion Monte Carlo (FW-PDMC) algorithm which attempts this has a serious bias. On the other hand, the DMC algorithm with minimal stochastic reconfiguration provides unbiased estimates of the energies, but the expectation values ($o|^|^) are contaminated by ^, an user specified, approximate wave function, when A does not commute with the Hamiltonian. We modified the latter algorithm to obtain the exact expectation values for these operators, while at the same time eliminating the bias. To compare the efficiency of FW-PDMC and the modified DMC algorithms we calculated simple properties of the H atom, such as various functions of coordinates and polarizabilities. Using three non-exact wave functions, one of moderate quality and the others very crude, in each case the results are within statistical error of the exact values.