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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
511

Efeito de frações peptídicas do veneno da serpente Bothrops jararaca (Serpentes, Viperidae: Crotalinae) sobre a atividade enzimática dipeptidil-peptidase IV (DPP-IV) e sobre o receptor (GLP-1R) do peptídeo glucagon-símile tipo 1 (GLP-1). / Effect of peptide fractions from Bothrops jararaca (Serpentes, Viperidae: Crotalinae) venom on dipeptidyl-peptidase IV (DPP-IV) enzyme activity and glucagon-like peptide 1 receptor (GLP-1R).

Leonardo Zambotti Villela 20 October 2010 (has links)
Novos agentes terapêuticos que preservem as células <font face=\"Symbol\">&#946 do pâncreas e o controle do peso são importantes para o diabetes melittus tipo 2 (DM-2), constituindo uma importante área de investimento farmacêutico. Com o objetivo de contribuir com a toxinologia comparada de venenos de répteis e com a eventual descoberta de novos agentes insulinotrópicos, o presente estudo realizou a prospecção de compostos hipoglicemiantes análogos à exendina-4 (isolada de lagartos Heloderma) ou inibidores da dipeptidil-peptidase IV (DPP-IV) no veneno da serpente Bothrops jararaca. A espectrometria de massas identificou uma K49 Fosfolipase A2 inédita neste veneno. Inibidores da DPP-IV não foram encontrados. Porém, a existência de frações polipeptídicas deste veneno sem similares estruturais descritos, sem efeito na pressão arterial média, imunologicamente similares à exendina-4 e com efeito hipoglicemiante e provável capacidade de ligação ao receptor do peptídeo glucagon-símile tipo 1, caracterizaram, pela primeira vez, a ação de veneno de serpente sobre o metaboloma. / New therapeutic agents that protect pancreatic <font face=\"Symbol\">&#946 cells and regulate body mass are important to diabetes mellitus type 2 (DM-2). The search for these agents is one of the main objectives of investments made by pharmaceutical industries. To contribute to the comparative toxinology studies of reptile venoms and to reveal new insulinotropic agents, the present investigation searched for hypoglycemiant compounds such as exendin-4 analogues (isolated from Heloderma lizards) or dipeptidyl-peptidase IV (DPP-IV) inhibitors in the venom of the snake Bothrops jararaca. The mass spectrometry analysis identified a novel K-49 Phospholipase A2 in this venom. DPP-IV inhibitors were not found. However, the existence of polypeptide fractions from this venom without structural similarity with reported compounds, without effect on mean arterial blood pressure and with immunological similarity with exendin-4 and probable ability to bind to glucagon-like peptide type 1 receptor, led to the first characterization of snake venom activity on metaboloma.
512

Efeito do inibidor da DPP-IV sobre glicemia, glucagon, insulina, peptídeo C, GLP-1 e ácidos graxos livres após dietas isocalóricas de diferentes composições nutricionais em pacientes diabéticos tipo 2 virgens de tratamentos / Effect of DPP-IV inhibitor on glycemia, glucagon, insulin, C-peptide, GLP-1, and free fatty acids after isocaloric diets with different nutritional compositions in drug-naïve patients recently diagnosed with type 2 diabetes

Cristina da Silva Schreiber de Oliveira 07 June 2013 (has links)
Introdução: A sitagliptina, inibidor da dipeptidil-peptidase IV, impede a degradação do GLP-1 (peptídeo-1 semelhante ao glucagon), um dos principais hormônios incretínicos. A dieta interfere na secreção de GLP-1, no entanto, a interação das drogas que aumentam o GLP-1 e os macronutrientes da dieta é pouco estudada. Objetivo e Métodos: Determinar o efeito da sitagliptina, na secreção de GLP-1, glucagon, insulina, peptídeo-C, ácidos graxos livres e na glicemia após três dietas, isocalóricas, de diferentes composições nutricionais em pacientes diabéticos tipo 2, recém-diagnosticados, virgens de tratamento, quando comparado a uso de placebo. Dezesseis indivíduos nessas condições foram submetidos a dietas hiperglicídica, hiperprotêica e hiperlipídica, isocalóricas entre si. Dosaram-se nos tempos 0, 30, 60, 120 e 180 minutos os parâmetros: glicose, insulina, peptídeo C, GLP-1, glucagon e AGL. Foi calculada média de área sob a curva e cálculo da área incremental, além de análise de variância para medidas repetidas. Resultados: Durante o teste de dieta hiperglicídica a glicemia foi maior em todos os tempos quando comparado aos testes com PTN e LPD independentemente do uso de sitagliptina (p<0,05). Sitagliptina diminuiu a glicemia em todos os tempos, quando comparado ao uso de placebo (p<0,05). Durante a dieta CHO, a secreção de glucagon foi menor que nas dietas LPD e PTN (p<0,05). Já a concentração de insulina foi maior com a dieta CHO em relação à dieta LPD (p<0,05). A concentração de insulina e peptídeo C foi maior em todos os tempos na dieta CHO (p<0,05). A concentração de GLP-1 foi significativamente maior durante o teste hiperlipídico em relação à dieta CHO. Durante a dieta LPD, a medida de GLP-1 foi maior em todos os tempos. A dieta CHO apresentou medida de GLP-1 menor em todos os tempos do que as outras dietas (p<0,05). A medida de GLP-1 no tempo foi maior (até 120\') com o uso de sitagliptina do que com o uso do placebo, apesar de não estatisticamente significativa. Os níveis de AGL no tempo foram maiores com o uso do placebo do que com o uso da sitagliptina, apesar de não estatisticamente significativo. Conclusão: Houve diminuição da glicemia em todos os tempos com sitagliptina, independentemente da dieta testada. Houve diminuição do efeito da sitagliptina durante o uso da dieta hiperglicídica / Background: Sitagliptin, a dipeptidil-peptidase IV inhibitor, prevents the degradation of GLP-1 (glucagon-like peptide 1), one of the incretin hormones. It is well-known that diet interferes in the GLP-1 secretion; however, the interaction between drugs that stimulates the release of GLP-1 and the macronutrients from diet is hardly studied. Objective and Methods: To demonstrate the effect of sitagliptin on glycemia, and on the secretion of GLP-1, glucagon, insulin, C-peptide, and free fatty acids after three isocaloric diets with different nutritional compositions, in drug-naïve patients, newly diagnosed with type 2 diabetes, when compared to the use of placebo. Sixteen individuals were subjected to a high-carbohydrate diet, a high-protein diet, and a high-fat diet, all of which with similar caloric values. At 0, 30, 60, 120 and180 minutes after the diet, glucose, insulin, C-peptide, GLP-1, glucagon, and AGL were measured. The mean area under the curve, the incremental area, and the variance for repeated measures were calculated. Results: During high-carbohydrate diet, glycemia was higher for all time points, when compared to the PTN and LPD diets, independently of sitagliptin (p<0,05). Sitagliptin reduced glycemia during three diets when compared to placebo (p<0,05). During CHO diet, secretion of glucagon was smaller than it was during the LDP and PTN diets (p<0,05). On the other hand, insulin concentration was higher than during the LPD diet (p<0,05). Concentrations of insulin and C-peptide were higher for all the time points during the CHO diet (p<0,05). GLP-1 concentration was significantly higher during the high-fat diet than during the high-carbohydrate diet. During the LPD diet, the quantity of the GLP-1 was larger for all time points. The CHO diet presented lower GLP-1 level, for all the time points, than the other diets (p<0,05). The GLP-1 level (up to 120min) with the use of sitagliptin was higher with LPD and PTN diet than it was with the CHO diet. The AGL levels for all time points were higher with placebo than with sitagliptin, although not statistically significant. Conclusion: There was a reduction in glycemia with sitagliptin, independently of the diet tested, for all time points. There was a reduction in sitagliptin effect during the use of the high-carbohydrate diet
513

Diagnostika plazmochemických depozičních procesů s využitím organokovových sloučenin / Diagnostics of plasma chemical deposition processes using organometallic precursors

Sahánková, Hana January 2011 (has links)
The aim of this work is diagnostic of plasma chemical deposition thin films based on organometallic precursors. Thin layers have recently become one of the most used methods for surface treatment of materials. They are used as a protective, functional layer, they improve surface properties of materials or increase or reduce the adhesion to various compounds. Plasma polymers are a modern trend in surface treatment technology. Their structure is different from classical polymers. The titanium (IV)isopropoxide was chosen as a monomer example, which is frequently used as a monomer for photocatalytic TiO2 films plasma deposition. These thin films are very promising for the removal of various air and water pollutants and thus they can significantly help in the increase of the environmental quality. Measurements took place on a commercial device Plasmatreater AS 400. The theoretical part describes the background needed for the study and diagnostics of plasma processes and technologies. The optical emission spectroscopy was chosen as a diagnostic method, and thus its principles are outlined in the theoretical part. Infrared spectroscopy and X-ray photoelectron spectroscopy were applied for the diagnostics of prepared thin films and they are also described in the theoretical part. The experimental part contains two sections. The first section is dedicated to the plasma diagnostics by optical emission spectroscopy. Discharge was generated in nitrogen or in the air. Measurements were performed at seven different duty cycles and at two different flow rates for each of the working gases. The molecular bands of nitrogen first negative and second systems, CN violet bands, and atomic lines of oxygen and nozzle elements (Cu, Cr) were identified in the spectra. The titanium lines, and bands of TiO were determined if the precursor was added. Electron temperature was calculated using chromium lines, and electron temperature maps were obtained for continuous mode and pulse mode with duty cycle 70% for nitrogen plasma with 500 sccm precursor flow. Similar discharge maps were also processed using the selected line of titanium (520 nm) TiO band (625 nm) again for the same discharge conditions. Furthermore, the dependences of the same quantities were obtained along the discharge axis as a function of duty cycle in both gases with precursor flow of 1000 sccm. The second part of results brings material analyzes of the deposited samples. The peaks of anatase and rutile have been identified by infrared spectroscopy. Using X-ray photoelectron spectroscopy, we found that our layers contain a significant amount of non-dissociated precursor. Moreover, a large number of radicals, which can interact with atmospheric gases, was determined on the surface. These radicals are removable by annealing or by ion etching. All results obtained during this research can significantly help us to improve the quality of deposited layers and allow us also some prediction of the thin film properties at given plasma conditions. Of course, further experimental as well as theoretical studies should be completed to obtain complete knowledge needed for the wide applications of these layers.
514

Výpočetní simulace přenosu zvukových signálů lidským uchem / Simulation of the sound transfer via human ear

Hájek, Petr January 2014 (has links)
The presented thesis concerns the biomechanics of hearing. The main aim of this work is the determination of so called corrections which allow for the comparison of synthetic audiograms and measured audiograms. With these corrections we attempt to overcome the discrepancy that exists between the computational modelling and audiological measurement. The discrepancy lies in a fact that the computational modelling usually simulates the sound coming from a free eld to the external auditory canal, while audiological measurement is realized by audiological headphones, whether the auditory system is healthy or injured. Then corrections adjust the computational model so that the obtained result is comparable to audiological measurement. In this work is also addressed the influence of stapes kinematics to the excitation of basilar membrane. The movement of stapes consists of piston-like movement and rocking movement. The computational simulation shows which movement is more signicant for the excitation of basilar membrane and how this effect can be used in otosurgery, in particular, for type IV of tympanoplasty.
515

Elektrodepozice tenkých tantalových vrstev z iontových roztoků a měření jejich elektrických vlastností / Electrodeposition of thin tantalum layers from ionic liquids and measurement of their electrical properties

Svobodová, Ivana January 2016 (has links)
The thesis is focused on the electrodeposition of tantalum from ionic solution 1-butyl-1- methylpyrrolidinium bis(trifluoromethylsulfonyl) imide, ([BMP]Tf2N) at 200°C and description of related transfer and kinetic phenomena on the interface between the ionic solution and working electrode. Furthermore, the electrodeposition of tantalum layers in different ionic solutions containing tantalum salts and especially in ([BMP]Tf2N) is introduced. In the last part of the thesis, results of cyclic voltammetry, surface analysis SEM and elemental analysis EDX are discussed. MIS (metal-insulator-semiconductor) structure was determined comprising porous anodic alumina as the insulator and semiconductive TaxOy on the top of the insulator. The electric conductivity of the MIS structures was studied by using amper-volt IV and CV characteristics. The results of the cyclic voltametry, impedance spectroscopy and chronoamperometry are discussed.
516

Nástěnné malby na hradě Karlštejn ve světle restaurátorských zásahů / The mural paintings in Karlštejn castle in the light of the restoration effects

Uchytilová, Barbora January 2019 (has links)
The mural paintings in Karlštejn castle in the light of the restoration effects This thesis focuses on the mural paintings located in Karlštejn castle. These mural paintings form a complex iconography of the entire castle, which weaves together all the sacred spaces of the castle, culminating in the Chapel in the Great Tower. The thesis deals with the mural paintings situated in two chapels in the first floor of the Imperial palace, so-called the Hall of Ancestors, where the genealogy of Charles IV. originally decorated this hall, the Church of the Virgin Mary and the Chapel of Saint Catherine inside the Marian Tower, on the walls of the staircase and in the Chapel of the Holy Cross, inside the Great Tower, not only in the light of the restoration effects, which may have affected and influenced the original appearance. Tracking of the origin of the re- paintings, followed by an iconographical analysis, draws from the restoration reports and archives connected with the last major reconstruction of the castle, which was led from Vienna by architects Fridrich Schmidt and Josef Mocker. I analyse their iconography and authorship, and evaluate the restoration efforts carried out in the last centuries. Key words: Middle Ages, mural paintings, 14th century, Karlštejn castle, Chapel of the Holly Cross, Master...
517

Legitimita královské moci. Edward IV. a Karel VII. Nezpochybnitelní a právoplatní králové? / The legitimacy of king's power. Edward IV. and Charles VII. indisputable and rightful kings?

Prošvicová, Lenka January 2020 (has links)
This diploma thesis is exploring the topic of legitimacy and legality of the royal power in the late English and French Middle Ages. Specifically, it answers the question whether Edward IV and Charles VII were legitimate kings for their respective subjects, based on analysis and comparison of selected contemporaneous English and French sources. This thesis presents different points of view on the royal power and the royal office according to the medieval authors. It describes the often ambiguous and contradictory opinions on this issue as well as provides a deeper look at the traditions and customs surrounding it. This analysis is presented against the historical backdrop of prolonged armed conflicts and political changes in both kingdoms. The differences between the legal and political situation of Charles VII and Edward IV suggest a wide range of possible interpretations. This thesis, based on the critical analysis and comparison of the relevant historical sources, advocates the view supporting the legitimacy of both kings, based on their respective genealogical and legal claims as well as on the support granted by their subjects. Keywords: Charles VII, Edward IV, royal power, legitimacy, treaty of Troyes, Wars of the Roses, Hundred years war
518

Verstärkung der Zelladhärenz und Induktion des Zell-Spreading - eine neue Funktion von RAGE, einem hoch selektiven Differenzierungsmarker humaner Alveolar-Typ 1-Zellen

Demling, Nina 08 July 2005 (has links)
RAGE (receptor for advanved glycation endproducts) was identified on endothelial cells as binding partner for AGE-modified molecules. The term &amp;quot;Advanced glycation endproducts&amp;quot; involves a number of structurally diverse molecules, which derive from multiple complex rearrangements of reducing sugars with free amino-groups of proteins. They evolve during food production and also in vivo during ageing and to an accelerated degree in diabetes, where AGEs cause receptor-mediated cellular perturbations. Due to the pathological relevance the aim of this thesis was to generate a &amp;quot;biosensor&amp;quot; for AGEs. To this end, the membrane-expressed receptor (flRAGE) as well as soluble RAGE (sRAGE) were expressed in mammalian cells and investigated in numerous binding studies. These did not reveal a specific interaction of AGE-modified ligands with RAGE. In addition, the expression of RAGE on endothelial cells, as described in the literature, could not be followed neither with the help of newly generated monoclonal anti-RAGE antibodies, nor in quantitative &amp;quot;real time&amp;quot; RT-PCR analysis. These results cast doubts on the meaning of RAGE as a proinflammatory receptor in AGE-mediated pathologies and on the adequacy of RAGE for the &amp;quot;biosensor&amp;quot;. At the same time the question concerning a physiological role of the receptor arose. RAGE-expression was analysed in different healthy human tissues by &amp;quot;real time&amp;quot; RT-PCR, which revealed an almost selective expression in lung tissue. An important indication for a possible physiological function of RAGE in lung provided the selective localization of RAGE on alveolar epithelial type I cells as demonstrated in frozen lung sections as well as in in vitro cultivated lung cells. RAGE could be identified as a novel, highly specific marker for the thin, expanded AT I cell, which form part of the air-blood-barrier. In the following, RAGE was found to be an interaction partner for collagen IV, a major component of the alveolar basal lamina. Membrane-expressed RAGE did not only strengthened adherence of cells but also induced cell spreading on collagen IV-coated surfaces. This preferential interaction of RAGE with collagen IV could substantially contribute to the functional morphology of AT I cells in vivo, thereby ensuring an effective bidirectional gas-exchange. The results of this thesis expose a novel, so far unnoticed aspect of the biology of RAGE, which presumably contributes to the phenotypic characteristic und function of normal human lung tissue. / RAGE (receptor for advanced glycation endproducts) wurde als Interaktionspartner auf Endothelzellen für AGE-modifizierte Moleküle identifiziert. Unter den &amp;quot;Advanced glycation endproducts&amp;quot; werden eine Vielzahl strukturell unterschiedlicher Moleküle zusammengefasst, die durch mehrstufige komplexe Umlagerungen zwischen reduzierenden Zuckern und freien Aminogruppen von Proteinen entstehen. Sie entstehen sowohl bei der Herstellung von Lebensmitteln, als auch in vivo während des Alterns und in erhöhtem Maß bei Diabetes, wobei sie Rezeptor-vermittelt Zellstörungen hervorrufen. In der vorliegenden Arbeit wurde zunächst aufgrund der pathologischen Relevanz eine Strategie zur Konzeption eines &amp;quot;Biosensors&amp;quot; für AGEs verfolgt. Hierfür wurde sowohl der membranständige Rezeptor (flRAGE) als auch löslicher RAGE (sRAGE) in Säugerzellen exprimiert und in zahlreichen Bindungs- und Funktionsanalysen getestet. Hierbei konnte keine spezifische Interaktion der AGE-modifizierten Moleküle mit RAGE nachgewiesen werden. Auch die in der Literatur beschriebene Expression von RAGE auf Endothelzellen konnte mit Hilfe neu generierter monoklonaler Antikörper, sowie in quantitativen &amp;quot;real time&amp;quot; RT-PCR-Analysen nicht nachvollzogen werden. Diese Ergebnisse warfen Zweifel an der grundlegenden Bedeutung von RAGE als proinflammatorischer Rezeptor in AGE-bedingten Krankheiten auf und stellten damit auch dessen Eignung für einen AGE-Biosensor in Frage. Gleichzeitig warf diese Skepsis die Frage nach einer möglichen physiologischen Funktion dieses Rezeptors auf. Eine vergleichende Analyse der RAGE-Expression in verschiedenen gesunden Geweben mittels &amp;quot;real time&amp;quot; RT-PCR ergab eine nahezu selektive Expression in Lungengewebe. Wichtige Anhaltspunkte für die Funktion von RAGE in der Lunge ergaben sich aus der selektiven Lokalisation des Rezeptors auf Alveolarepithelzellen Typ I (AT I) sowohl in Gefrierschnitten der Lunge als auch nach in vitro-Kultur von Lungenzellen. RAGE konnte als neuer, hoch spezifischer Marker für die lang gestreckten AT 1 Zellen, die einen Teil der Blut-Luft-Schranke bilden, definiert werden. In folgenden Funktionsanalysen konnte RAGE als spezifischer Interaktionspartner für Kollagen IV, einer Hauptkomponente der Alveolar-Basalmembran, identifiziert werden. Membranständiger RAGE verstärkte nicht nur die Adhärenz von Zellen an Kollagen IV-beschichtete Oberflächen, er induzierte auch Zell-&amp;quot;Spreading&amp;quot;. Dies gab Anlass für die Vermutung, dass die beobachtete präferentielle Interaktion von RAGE mit Kollagen IV maßgeblich zu der funktionellen Morphologie der AT I Zellen in vivo beitragen könnte, die die Voraussetzung für einen effektiven bidirektionalen Gasaustausch darstellt. Durch die Ergebnisse dieser Arbeit wurde ein neuer, bisher unbeachteter Aspekt der Biologie des RAGE aufgedeckt, der vermutlich entscheidend zur phänotypischen Ausprägung und Funktion des normalen humanen Lungengewebes beiträgt.
519

DSM-IV pain disorder in the general population: An exploration of the structure and threshold of medically unexplained pain symptoms

Fröhlich, Christine, Jacobi, Frank, Wittchen, Hans-Ulrich January 2006 (has links)
Background: Despite an abundance of questionnaire data, the prevalence of clinically significant and medically unexplained pain syndromes in the general population has rarely been examined with a rigid personal-interview methodology. Objective To examine the prevalence of pain syndromes and DSM-IV pain disorder in the general population and the association with other mental disorders, as well as effects on disability and health-care utilization. Methods: Analyses were based on a community sample of 4.181 participants 18–65 years old; diagnostic variables were assessed with a standardized diagnostic interview (M-CIDI). Results: The 12-month prevalence for DSM-IV pain disorder in the general population was 8.1%; more than 53% showed concurrent anxiety and mood disorders. Subjects with pain disorder revealed significantly poorer quality of life, greater disability, and higher health-care utilization rates compared to cases with pain below the diagnostic threshold. The majority had more than one type of pain, with excessive headache being the most frequent type. Conclusions: Even when stringent diagnostic criteria are used, pain disorder ranks among the most prevalent conditions in the community. The joint effects of high prevalence in all age groups, substantial disability, and increased health services utilization result in a substantial total burden, exceeding that of depression and anxiety.
520

Characterization of Pol IV and Pol V-Dependent Non-Coding RNAs Derived from aGeminivirus Genome

Ostler, Jeffery Brent, Jr. 15 August 2017 (has links)
No description available.

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