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Estudo do L-histidinato de níquel (II) monohidratado sob condições extremas de temperatura e pressão por Espectroscopia Raman / Study of L-histidinate nickel (II) monohydrous under extreme conditions of temperature and pressure by Raman SpectroscopyMaia, José Robson January 2014 (has links)
MAIA, José Robson. Estudo do L-histidinato de níquel (II) monohidratado sob condições extremas de temperatura e pressão por Espectroscopia Raman. 2014. 106 f. Tese (Doutorado em Física) - Programa de Pós-Graduação em Física, Departamento de Física, Centro de Ciências, Universidade Federal do Ceará, Fortaleza, 2014. / Submitted by Edvander Pires (edvanderpires@gmail.com) on 2015-04-09T20:15:54Z
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Previous issue date: 2014 / In this work bis(L-histidinato)nikel(II) Monohydrate crystals were obtained by slow evaporation method using 1 mol of NiCl2.6H2O, 2 mols of L-histidine and NaOH. Reitveld refinement of X-ray data confirmed the structure. Raman modes obtained at ambient conditions of pressure and temperature were assigned by comparison with results on similar materials and by density functional theory DFT calculations. PED (potential energy distribution) is also present. Raman spectroscopy measurements were performed from room temperature up to 150 oC in the 50- 3500 cm-1 spectral range. For temperatures higher than 125 oC the modes related with the water stretching disappeared as well as the lattice modes disappeared indicating a phase transition undergone by the crystal. DSC experiments support this assumption. By decreasing temperature up to 18 K in the 40-3500 cm-1 spectral range it was observed modifications only in internal modes, so we believe that some conformational change has been occurred in the molecules of bis(L-histidinate)nikel(II) Monohydrate. High pressure experiments were performed from ambient pressure up to 9,5 GPa in the 50-3500 cm-1 spectral range. Disappearance of modes between 0,4 and 0,8 GPa was interpreted as evidences of a structural phase transition undergone by the crystal. A second set of modifications in the spectra indicates other phase transition experienced by the crystal between 2,6 and 3,2 GPa. The spectrum obtained the realizing pressure points out to the irreverbility of the phase transitions. / Neste trabalho cristais de L-histidinato de níquel (II) monohidratado (Ni(C6H8N3O2)2.H2O) foram obtidos por meio da evaporação lenta do solvente de uma solução saturada de 1 mol de NiCl2.6H2O, 2 mols de L-histidina mais NaOH. Após a obtenção da amostra a confirmação da estrutura deu-se por refinamento do Reitveld. A classificação dos modos vibracionais à temperatura e pressão ambiente foi realizada por comparação com outros materiais e através de cálculos de teoria da densidade do funcional DFT. A distribuição da energia potencial (PED) também foi calculada. Experimentos de espectroscopia Raman variando a temperatura desde a temperatura ambiente até 150 0C, foram realizadas no cristal de L-histidinato de níquel (II) monohidratado no intervalo espectral entre 50 e 3500 cm-1. Para temperaturas superiores a 125 0C o desaparecimento e surgimento de modos na região dos modos da rede bem como na região dos modos internos indicam uma transição de fase estrutural no L-histidinato de níquel (II) monohidratado devido à saída de água. A transição é irreversível pois o espectro obtido após a amostra retornar a temperatura ambiente é bem diferente daquele obtido no início do experimento. Experimentos de DSC corroboram com o experimento de espectroscopia Raman pois indicam a saída da molécula de água do cristal de L-histidinato de níquel (II) monohidratado no valor de temperatura de 140 0C, e ainda perda de massa de água na mesma temperatura (140 0C), relatada pela curva de TG. Nos experimentos de espectroscopia Raman a baixas temperaturas a amostra de L-histidinato de níquel (II) monohidratado foi resfriada desde a temperatura ambiente até 18 K no intervalo espectral de 40 a 3500 cm-1. Observou-se o surgimento de alguns modos internos, porém, como não evidenciou-se mudanças nos modos externos supomos que o material deva sofrer apenas uma mudança conformacional. Os experimentos de espectroscopia Raman a altas pressões foram realizados no intervalo de pressão entre 0,1 e 9,5 GPa, em um intervalo espectral de 50 a 3500 cm-1. Com o aumento da pressão percebe-se o desaparecimento de modos indicando uma transição de fase estrutural entre 0,4 e 0,8 GPa. Aumentando-se ainda mais a pressão observa-se o surgimento de três modos em torno da frequência de 50 cm-1 no intervalo de pressão entre 2,6 e 3,2 GPa. Estas mudanças indicam uma segunda transição de fase estrutural da amostra de L-histidinato de níquel (II) monohidratado. O espectro obtido após a descompressão é idêntico aquele do início do experimento indicando reversibilidade da transição.
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Außentemperatur, Jahreszeit und individuelle Trajektorien beeinflussen den Blutdruck von Kindern, Jugendlichen und jungen Erwachsenen.Miersch, André 26 March 2014 (has links)
Background: Seasonal fluctuations in outdoor temperature have been shown to affect blood pressure in adults. We have asked whether or not there is either a seasonal variation or an influence of outdoor temperature on blood pressure measurements in children and adolescents in middle Europe.
Methods: Blood pressure was routinely measured in healthy and sick children and adolescents in outpatient clinics and during hospitalisation in a total of 6714 subjects (3,497 boys/3,237 girls), age 3 to 21 years, with a median of 10.6 years.
Results: Cross-sectional analysis showed a significant seasonal variation in blood pressure measurements. The mean increase of systolic and diastolic blood pressure was 4.45/2.42 mmHg during winter. A significant correlation between average outdoor temperatures and systolic blood pressure was found (ρ=-0.074 p<0.001). However, the effect was only detectable at an average temperature below 0° C/32° F and above 10° C/50° F. For each degree Celsius increase in average outdoor temperature, the systolic blood pressure fell by 0.12 mmHg.
Conclusion: Blood pressure measurements in children and adolescents, even in a temperate climate, are influenced by temperature and seasonal variation. Considering seasonal variations in blood pressure could be of clinical interest.:Inhaltsverzeichnis......................................................................i
Widmung .................................................................................. iii
Bibliographische Beschreibung ................................................. iv
I. Abkürzungen ......................................................................... i
1. Einführung ........................................................................... 1
1.1. Bedeutung von Blutdruckmessungen im Allgemeinen ................................................................................................. 1
1.2. Bedeutung und Durchführung von Blutdruckmessungen bei Kindern und Jugendlichen ................................................................................................ 2
1.3. Tracking ................................................................................................ 4
1.4. Innere und äußere Einflussfaktoren des Blutdrucks ................................................................................................ 5
1.5. Zweck der Studie ................................................................................................ 7
2. Publikationsmanuskript ................................................................................................ 10
2. 1. Influence of seasonal variation on blood pressure measurements in children, adolescents and young adults ................................................................................................ 10
Abstract .................................................................................. 11
Introduction ................................................................................................ 12
Subjects and methods ................................................................................................ 13
Results .................................................................................... 15
Discussion ................................................................................................ 18
Conclusion ................................................................................................ 21
Acknowledgements ................................................................................................ 22
References............................................................................... 23
Tables ..................................................................................... 27
Figure legends ................................................................................................ 29
Figures ................................................................................... 30
2.2. Blood pressure tracking in children and adolescents ....... 33
Abstract .................................................................................. 34
Inhaltsverzeichnis
Subjects and methods ................................................................................................ 35
Results .................................................................................... 39
Discussion ................................................................................................. 42
Conclusion ................................................................................................. 44
Acknowledgements ................................................................................................. 45
References................................................................................ 46
Legends to figures .................................................................................................. 53
Figures ...................................................................................... 55
3. Zusammenfassung der Arbeit ................................................................................................... 62
4. Literaturverzeichnis ............................................................... 68
II. Erklärung über die eigenständige Abfassung der Arbeit ........ ii
III. Lebenslauf ............................................................................ iii
IV. Danksagung .................................................................................................... iv / Background: High blood pressure is a major risk factor for cardiovascular disease. Blood pressure tracking could help to identify individuals with potential hypertension. Therefore, we have asked whether or not tracking was of predictive value for the development of hypertension in early life.
Methods: Blood pressure was routinely measured in 13,261children and adolescents in outpatient clinics as well as during hospitalization. In a sub-analysis 568 individuals with normotensive and elevated blood pressure were compared after three follow-up periods (two, four and six years) and 2,157 normotensive individuals were compared in a paired t-test.
Results: The follow-up analysis showed a significant tracking effect. However, the Pearson correlation coefficients of the systolic and diastolic blood pressure SDS decreased over time. Upon the follow-up after six years 35.6% of the children and adolescents with elevated blood pressure values remained in the elevated range group. Of the children within the normotensive blood pressure range 80.4% remained normotensive after six years. Children with normotensive blood pressure showed a stronger tracking than those who had had one hypertensive blood pressure reading. Children with high body weight gain left their SDS track to higher blood pressure values.
Conclusion: Blood pressure tracking in children and adolescents is moderate. We conclude that the predictive power of a single hypertensive blood pressure measurement during a single visit is rather small, and thus repetitive measurements across several consecutive visits are necessary.:Inhaltsverzeichnis......................................................................i
Widmung .................................................................................. iii
Bibliographische Beschreibung ................................................. iv
I. Abkürzungen ......................................................................... i
1. Einführung ........................................................................... 1
1.1. Bedeutung von Blutdruckmessungen im Allgemeinen ................................................................................................. 1
1.2. Bedeutung und Durchführung von Blutdruckmessungen bei Kindern und Jugendlichen ................................................................................................ 2
1.3. Tracking ................................................................................................ 4
1.4. Innere und äußere Einflussfaktoren des Blutdrucks ................................................................................................ 5
1.5. Zweck der Studie ................................................................................................ 7
2. Publikationsmanuskript ................................................................................................ 10
2. 1. Influence of seasonal variation on blood pressure measurements in children, adolescents and young adults ................................................................................................ 10
Abstract .................................................................................. 11
Introduction ................................................................................................ 12
Subjects and methods ................................................................................................ 13
Results .................................................................................... 15
Discussion ................................................................................................ 18
Conclusion ................................................................................................ 21
Acknowledgements ................................................................................................ 22
References............................................................................... 23
Tables ..................................................................................... 27
Figure legends ................................................................................................ 29
Figures ................................................................................... 30
2.2. Blood pressure tracking in children and adolescents ....... 33
Abstract .................................................................................. 34
Inhaltsverzeichnis
Subjects and methods ................................................................................................ 35
Results .................................................................................... 39
Discussion ................................................................................................. 42
Conclusion ................................................................................................. 44
Acknowledgements ................................................................................................. 45
References................................................................................ 46
Legends to figures .................................................................................................. 53
Figures ...................................................................................... 55
3. Zusammenfassung der Arbeit ................................................................................................... 62
4. Literaturverzeichnis ............................................................... 68
II. Erklärung über die eigenständige Abfassung der Arbeit ........ ii
III. Lebenslauf ............................................................................ iii
IV. Danksagung .................................................................................................... iv
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