562 research outputs found
Abhängigkeiten zwischen Objekten in ingenieurwissenschaftlichen Anwendungen
Objektorientierte Anwendungen aus dem Ingenieurwesen bestehen aus strukturierten Mengen, deren Elemente Objekte sind. Zwischen den Objekten bestehen vielfältige Abhängigkeiten. Die Beziehungen sind zur Zeit der Entwicklung einer Anwendung nur teilweise bekannt. Beziehungen zwischen Objekten müssen deshalb auch zur Laufzeit der Anwendung erzeugt und gelöscht werden können. Aufgrund des hohen Rechenaufwandes wird die Objektbasis einer Anwendung verzögert aktualisiert. Eine objektorientierte Anwendung wird auf Grundlage der Systemtheorie als System formal beschrieben. Als Elemente des Systems werden Attribute, Objekte und Objektmengen eingeführt. Die in den Methoden der Objekte implementierten Algorithmen bestimmen die Bindungsrelation des Systems. Auf Grundlage der Graphentheorie wird die Reihenfolge der Aktualisierung der Objektbasis berechnet. ..
Bypassing the structural bottleneck in the ultrafast melting of electronic order
The emergent properties of quantum materials, such as symmetry-broken phases
and associated spectral gaps, can be effectively manipulated by ultrashort
photon pulses. Impulsive optical excitation generally results in a complex
non-equilibrium electron and lattice dynamics that involves multiple processes
on distinct timescales, and a common conception is that for times shorter than
about 100 fs the gap in the electronic spectrum is not seriously affected by
lattice vibrations. Here, we directly monitor the photo-induced collapse of the
spectral gap in a canonical charge-density-wave material, blue bronze
Rb0.3MoO3. We find that ultra-fast (about 60 fs) vibrational disordering due to
efficient hot-electron energy dissipation quenches the gap significantly faster
than the typical structural bottleneck time corresponding to one half-cycle
oscillation (about 315 fs) of the coherent charge-density-wave amplitude mode.
This result not only demonstrates the importance of incoherent lattice motion
in the photo-induced quenching of electronic order, but also resolves the
perennial debate about the nature of the spectral gap in a coupled
electron-lattice system
Spektroskopische und mikroskopische Untersuchung von Phasenübergängen in stark korrelierten Übergangsmetallverbindungen
Stark korrelierte Materialien offenbaren einige der faszinierendsten, aber auch herausforderndsten physikalische Phänomene unserer Zeit. Sie offenbaren vielfältige Phasenübergänge, wie Metall-Isolator-Übergänge, das Auftreten von Supraleitung, Ferroelektrizität, Spin- und Ladungsdichtewellen. Besonders Vertreter der Übergangsmetallverbindungen weisen starke Wechselwirkungen zwischen Ladung, Gitter, Spin- und orbitaler Ordnung auf. Durch die Möglichkeit zur Miniaturisierung und die kontrollierbaren elektronischen Ordnungsparameter bieten sie ein enormes Erweiterungspotential in der Mikroelektronik, beispielsweise für Sensoren oder nichtflüchtige, ultraschnelle Speicherbausteine. Zur vollen Ausnutzung des Potentials dieser Materialien ist das Studium der mikroskopischen Mechanismen von zentraler Bedeutung, da praktisch alle Makroeigenschaften aus den mikroskopischen Abläufen resultieren.
Daher ist die Zielsetzung dieser Arbeit, Phasenübergänge ausgewählter Vertreter dieser Materialklasse während des Übergangs, unter variablen äußeren Einflüssen, wie Temperaturänderungen, elektrischen Feldern sowie Gitterdeformationen zu studieren. Hierfür wird auf verschiedene röntgenspektroskopische und -mikroskopische Methoden zurückgegriffen, die einen mikroskopischen Einblick in die elektronische Strukturen der untersuchten Modell- und anwendungsnahen Systeme realisieren.Correlated electron materials exhibit some of the most exotic, dramatic, and intellectually challenging behavior in the quantum world. They offer enormous potential to expand the scope of operation in modern microelectronics with their fascinating ordering phenomena, e.g. metal-to-insulator transitions or charge-density waves (CDW). One example for this type of materials are the transition-metal compounds that are promising candidates for realizing future devices. Employing their ability of energy efficient switching between distinct collective highly correlated electronic states, they are supposed to replace the conventional silicon-based semiconductor technology for added functionality and miniaturization down to the nanoscale. It is necessary to study their microscopic properties to fully understand their complete potential.
Consequently, the goal of this work was to establish in operando techniques and study the electronic structure of transition-metal-compound candidates during selected phase transitions. This aim was achieved by applying spectroscopic and microscopic methods based on x-rays, focusing on the in operando ability
Antihypertensive Treatment of Pre-eclampsia: pharmacological aspects of ketanserin and nicardipine
Pre-eclampsia is a disease occurring in 2-8% of
the pregnant women and it forms one of the leading causes of maternal
and neonatal mortality and morbidity during pregnancy. The main
clinical characteristics of pre-eclamptic patients are elevated blood
pressure and proteinuria, occurring after the twentieth week of
gestation. Treatment with antihypertensive drugs is indicated to
prevent maternal complications like organ failure or cerebral
haemorrhages, and, in selected cases, to prolong the pregnancy to
improve neonatal outcome. In this thesis, the efficacy and safety in
pre-eclampsia of two new antihypertensive drugs, the 5-HT2A receptor
antagonist ketanserin and the calcium-channel blocking agent
nicardipine, are studied.
Intravenous administration of ketanserin to 47 early, onset, pre-
eclamptic patients showed that an adequate antihypertensive response
could not be obtained with ketanserin in one third of the patients,
despite maximum dosages. High plasma concentrations were obtained in
almost all patients, which renders a pha
Potential prediction of formulation performance in paediatric patients using biopharmaceutical tools and simulation of clinically relevant administration scenarios of nifedipine and lorazepam
Aims: This study explores the impact of paediatric patient related factors and choice of formulation on the dissolution characteristics of nifedipine and lorazepam, 2 drug substances regularly applied in very young patients and in compounded formulations. Methods: Dissolution experiments were designed to reflect clinical practice in a paediatric hospital, with respect to dosage forms, feeding regimens and methods of administration. Solubility studies addressed the influence of age and prandial state. Drug solubility and dissolution experiments were conducted in biorelevant media and adapted age-specific (neonate and infant) media. Dissolution studies were performed with the mini-paddle apparatus and the flow-through cell apparatus. Results: Dissolution of nifedipine formulations was not affected by age-related changes of the fasted state simulated gastrointestinal fluids, and by disintegration of the formulation before administration. However, a significant difference in nifedipine's dissolution rate from commercial tablets and compounded capsules was observed. The dissolution of lorazepam tablets was affected by fasted- vs fed-state media, but it was deemed less likely to be clinically relevant. The significant effect of fed-state media on nifedipine's solubility was considered to have possible clinical relevance since very young patients are almost continuously in a fed state. Conclusion: The in vitro results obtained from these studies reveal the potential of biorelevant solubility and dissolution studies reflecting clinical practice to predict drug performance in paediatric patients.</p
O surgimento do outro e a escrita de pedro
Throughout a case report we intend to ilustrate how a child that is being streatted at Lugar de Vida and was not having proper educational assistance due to parent's dinamic, can suffer from the effects of a treatment that is structured somewhere in between Psychoanalysis and Education and that is being called "Educação Terapêutica". Our approach for that matter will be diferential dygnosis, the effects of treatment on parents and the specific subjectivity process of this child.Através do relato de um caso, pretendemos iliustrar como uma criança que chegou ao "Lugar de Vida" com uma parada no investimento educativo devido à fantasmática parental em jogo, pôde sofrer os efeitos de um tratamento que se estrutura a partir do encontro entre a Psicanálise e a Educação, que temos chamado de Educação Terapêutica. Para isso abordaremos questões como o diagnóstico diferencial, os efeitos do tratamento nos pais e o particular processo de subjetivação dessa criança
A reprovação e a interrupção escolar nas quintas séries do ensino fundamental: o difícil percurso para continuidade dos estudos
Tese (doutorado) - Universidade Federal de Santa Catarina, Centro de Ciências da Educação. Programa de Pós-Graduação em Educação.Este estudo teve a intenção de compreender as relações que os alunos que vivenciaram situações de reprovação e interrupção escolar desenvolveram com a escola, e a forma como percebem a realidade escolar. Para compreender essas relações foi importante considerar as dimensões Macro, Meso e Micro nos quais tais processos se produziram e reproduziram. A escolha desse objeto de estudo impôs a necessidade de buscar informações que permitissem a articulação entre as pesquisas quantitativas e as qualitativas. Essa busca possibilitou o surgimento de pistas e a ampliação do foco de análise para entendimento das situações escolares vividas pelos alunos. A crítica às estatísticas, em nível nacional e local, e os limites impostos por esses dados impuseram um trabalho de garimpagem nos relatórios produzidos nas escolas e o deslocamento do olhar para outras informações singulares. Assim, procurou-se analisar projetos, ações educativas, e as formas de organização das redes de ensino e da avaliação do rendimento escolar, especificamente nas onze escolas estaduais e municipais selecionadas para o estudo, em Florianópolis. Foram escolhidas escolas que apresentavam indicadores de reprovação e interrupção escolar acima das médias estaduais e municipais. Como foco principal foram reconstruídas histórias escolares de treze alunos que vivenciaram situações múltiplas de reprovação e de interrupção escolar nas quintas series do Ensino Fundamental, no sentido de entender como configurações familiares e social semelhantes engendravam níveis de adaptação escolar tão diferentes. Tratou-se, da construção de Perfis de Configurações Social baseados na constatação de que a reprovação e a interrupção escolar não tinham causa única, e que além de ocorrerem em razão de uma multiplicidade e conjugação de fatores, também dependiam do tipo de relações estabelecidas entre os diferentes sujeitos e as inter-relações entre família-escola-trabalho. Para elaboração dos perfis tomou-se como ponto de partida a metodologia desenvolvida por Lahire ao utilizar a antropologia da interdependência, a sociologia que pensa as relações sociais sem determinismos imobilizantes e por considerar tanto as singularidades como as generalidades como partes de uma rede de relações de interdependência humana (LAHIRE, 1997, p. 40). 0 estudo permitiu concluir que as situações de reprovação e interrupção escolar são conseqüência da combinação de uma multiplicidade de fatores. Esse entrelaçamento de situações sinalizou condições mais ou menos favoráveis as relações escolares que esses estudantes vinham desenvolvendo e as possibilidades de continuidade dos estudos. Também, estabeleceu forte correlação entre a reprovação e a interrupção escolar, tornando ainda mais irregular as trajetórias escolares desses alunos
Distinct associations between plasma osteoprotegerin, homoarginine and asymmetric dimethylarginine in chronic kidney disease male patients with coronary artery disease
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