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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.
1

Obtenção, caractetizações estruturais e atividade enzimática do sítio C-catalítico da enzima conversora de angiotensina I - região ALA959 até SER1066 / Obtaining, structural characterization and enzymatic activity of the C catalytic site of angiotensin convertin enzyme I ALA959 to SER1066 region

Elias, Caroline Cristina 25 September 2015 (has links)
A enzima conversora de angiotensina (ECA) catalisa a conversão de angiotensina I (Ang I) no vasoconstritor angiotensina II (Ang II) e hidrolisa a bradicinina (BK). ECA somática (sECA) possui dois domínios homólogos (N e C) que têm 60% de identidade. Embora estas duas regiões tenham homologia grande, o sítio catalítico C-domínio exibe uma atividade três vezes maior do que o N-domínio na hidrolise de Ang I in vivo. Este fato torna interessante o desenvolvimento de novos estudos de inibidores ou a melhoria dos já existentes. O objetivo deste estudo foi obter a região Ala959 até Ser1066 do Cdomínio da sECA (c-sECA), em uma estrutura conformacional semelhante à estrutura nativa. Nós amplificamos a sequência correspondente ao sítio catalítico da c-sECA com 324pb e clonamos esta sequência no vetor pET 28a(+). O segmento (nomeado de pET28_c-sECA) foi expresso em sistema bacteriano. A proteína foi expressa na forma solúvel e a purificação foi feita em uma única etapa utilizando a coluna de afinidade His-tag, a qual produziu a proteína pura. Análises estruturais por dicroísmo circular e fluorescência confirmaram que a proteína recombinante estava na conformação correta, e os ensaios de atividade mostraram que a c-sECA possui atividade enzimática e é inibida por lisinopril. / The angiotensin-converting enzyme (ACE) catalyzes the conversion of angiotensin I (Ang I) to the vasoconstrictor angiotensin II (Ang II) and the hydrolysis of bradykinin (BK). Human somatic ACE (sACE) has two homologous domains (N and C) that show 60% identity. Although these two regions have high homology, the catalytic site of the C-domain exhibits three times more activity than that of the N-domain in the hydrolysis of Ang I in vivo. This fact necessitates the development of new inhibitors or the improvement of existing ones. This study aimed to obtain the Ala959 to Ser1066 catalytic region of C-domain of sACE (c-sACE) in a structural conformation that resembles the native structure. We amplified the 324-bp sequence corresponding to the catalytic site of c-sACE and cloned this sequence into a pET28a(+) vector. The segment (named pET28_c-sACE) was expressed in a bacterial system. The expressed protein segment was soluble, and its purification was performed in one step using a His-tag affinity column. Structural analysis by circular dichroism and fluorescence confirmed that the purified protein is correctly folded, and an activity assay showed that c-sACE possesses enzymatic activity and is inhibited by lisinopril.
2

Obtenção, caractetizações estruturais e atividade enzimática do sítio C-catalítico da enzima conversora de angiotensina I - região ALA959 até SER1066 / Obtaining, structural characterization and enzymatic activity of the C catalytic site of angiotensin convertin enzyme I ALA959 to SER1066 region

Caroline Cristina Elias 25 September 2015 (has links)
A enzima conversora de angiotensina (ECA) catalisa a conversão de angiotensina I (Ang I) no vasoconstritor angiotensina II (Ang II) e hidrolisa a bradicinina (BK). ECA somática (sECA) possui dois domínios homólogos (N e C) que têm 60% de identidade. Embora estas duas regiões tenham homologia grande, o sítio catalítico C-domínio exibe uma atividade três vezes maior do que o N-domínio na hidrolise de Ang I in vivo. Este fato torna interessante o desenvolvimento de novos estudos de inibidores ou a melhoria dos já existentes. O objetivo deste estudo foi obter a região Ala959 até Ser1066 do Cdomínio da sECA (c-sECA), em uma estrutura conformacional semelhante à estrutura nativa. Nós amplificamos a sequência correspondente ao sítio catalítico da c-sECA com 324pb e clonamos esta sequência no vetor pET 28a(+). O segmento (nomeado de pET28_c-sECA) foi expresso em sistema bacteriano. A proteína foi expressa na forma solúvel e a purificação foi feita em uma única etapa utilizando a coluna de afinidade His-tag, a qual produziu a proteína pura. Análises estruturais por dicroísmo circular e fluorescência confirmaram que a proteína recombinante estava na conformação correta, e os ensaios de atividade mostraram que a c-sECA possui atividade enzimática e é inibida por lisinopril. / The angiotensin-converting enzyme (ACE) catalyzes the conversion of angiotensin I (Ang I) to the vasoconstrictor angiotensin II (Ang II) and the hydrolysis of bradykinin (BK). Human somatic ACE (sACE) has two homologous domains (N and C) that show 60% identity. Although these two regions have high homology, the catalytic site of the C-domain exhibits three times more activity than that of the N-domain in the hydrolysis of Ang I in vivo. This fact necessitates the development of new inhibitors or the improvement of existing ones. This study aimed to obtain the Ala959 to Ser1066 catalytic region of C-domain of sACE (c-sACE) in a structural conformation that resembles the native structure. We amplified the 324-bp sequence corresponding to the catalytic site of c-sACE and cloned this sequence into a pET28a(+) vector. The segment (named pET28_c-sACE) was expressed in a bacterial system. The expressed protein segment was soluble, and its purification was performed in one step using a His-tag affinity column. Structural analysis by circular dichroism and fluorescence confirmed that the purified protein is correctly folded, and an activity assay showed that c-sACE possesses enzymatic activity and is inhibited by lisinopril.
3

An educational law perspective on educator professionalism / Tladi Petros Taunyane

Taunyane, Tladi Petros January 2006 (has links)
This research study deals mainly with the educator professionalisation in the post democratic South Africa, paying attention to the role of a professional council in promoting educator professionalism. The status and image of teaching in this country seem to have been viewed From the racial and cultural differences of communities previously. The democratic dispensation brought an end to this unfair racial and cultural discrimination in the education system through the establishment of a non-racial professional council for educators (i.e. SACE). The research aims are to determine: - The characteristics of a professions and those needed for educator professionalism; and - the role of the a professional council in promoting educator professionalisation. In order to attain the above-mentioned research aims, a literature review and an empirical investigation were undertaken. The literature study was used to clarify concepts such as occupation, semi-profession, profession, professionalisation and professional status. Secondly, characteristics or common features associated with traditional models of professions (ie. accounting, law and medicine) were discussed from a theoretical point of view. Lastly, the literature study highlighted the establishment of professional councils for educators in other parts of the world, including South Africa. The different forms of legislation and policy documents applicable in education were discussed. In order to determine the extent to which teaching adheres to or fulfils the characteristics associated with a profession, teaching was tested against these characteristics. The history of the establishment of SACE was briefly discussed and the objectives or role of this organisation in educator professionalisation concluded this chapter. The empirical research was conducted by using the questionnaire as a measuring instrument. The advantages and disadvantages of the questionnaire as measuring instrument were highlighted. The target population comprises of 239 educators from a total population of 2070 educators in Lejweleputswa and Northern Free State Education Districts -Free State Province. The data collected in the investigation was processed through the SAS computer package to establish frequencies and percentages of responses mean scores ranking, t-test procedures and the effect sizes. The results were then presented tables, analysed and interpreted in accordance with the literature study. The literature study revealed that like all other occupations, teaching aspires to attain recognition and status as a profession. It was also revealed that teaching partially satisfy characteristics associated with professions. The empirical study revealed that the employment of un- or under qualified educators is still prevalent in South African schools. In the last chapter, Chapter 5, conclusions from the literature review and empirical investigation were drawn. The recommendations with regard to the role of SACE in educator professionalisation were provided. Finally based on the research, future research studies in SACE and educator professionalism were recommended. / Thesis (M.Ed.)--North-West University, Potchefstroom Campus, 2006.
4

An educational law perspective on educator professionalism / Tladi Petros Taunyane

Taunyane, Tladi Petros January 2006 (has links)
This research study deals mainly with the educator professionalisation in the post democratic South Africa, paying attention to the role of a professional council in promoting educator professionalism. The status and image of teaching in this country seem to have been viewed From the racial and cultural differences of communities previously. The democratic dispensation brought an end to this unfair racial and cultural discrimination in the education system through the establishment of a non-racial professional council for educators (i.e. SACE). The research aims are to determine: - The characteristics of a professions and those needed for educator professionalism; and - the role of the a professional council in promoting educator professionalisation. In order to attain the above-mentioned research aims, a literature review and an empirical investigation were undertaken. The literature study was used to clarify concepts such as occupation, semi-profession, profession, professionalisation and professional status. Secondly, characteristics or common features associated with traditional models of professions (ie. accounting, law and medicine) were discussed from a theoretical point of view. Lastly, the literature study highlighted the establishment of professional councils for educators in other parts of the world, including South Africa. The different forms of legislation and policy documents applicable in education were discussed. In order to determine the extent to which teaching adheres to or fulfils the characteristics associated with a profession, teaching was tested against these characteristics. The history of the establishment of SACE was briefly discussed and the objectives or role of this organisation in educator professionalisation concluded this chapter. The empirical research was conducted by using the questionnaire as a measuring instrument. The advantages and disadvantages of the questionnaire as measuring instrument were highlighted. The target population comprises of 239 educators from a total population of 2070 educators in Lejweleputswa and Northern Free State Education Districts -Free State Province. The data collected in the investigation was processed through the SAS computer package to establish frequencies and percentages of responses mean scores ranking, t-test procedures and the effect sizes. The results were then presented tables, analysed and interpreted in accordance with the literature study. The literature study revealed that like all other occupations, teaching aspires to attain recognition and status as a profession. It was also revealed that teaching partially satisfy characteristics associated with professions. The empirical study revealed that the employment of un- or under qualified educators is still prevalent in South African schools. In the last chapter, Chapter 5, conclusions from the literature review and empirical investigation were drawn. The recommendations with regard to the role of SACE in educator professionalisation were provided. Finally based on the research, future research studies in SACE and educator professionalism were recommended. / Thesis (M.Ed.)--North-West University, Potchefstroom Campus, 2006.
5

Implementace nových vzduchových jističů ABB SACE Emax 2 do produktové řady nízkonapěťových rozváděčů MNS / Implementation of the new ABB SACE Emax 2 air circuit breaker series in a low-voltage MNS switchgear product portfolio

Studený, Michal January 2014 (has links)
The Master’s Thesis comprises a summary of the differences existing design of MNS switchgear series against AGOMIN project innovative proposal. The introduction deals with the introduction to the CAD program SolidWorks and its extension for enterprise data management SolidWorks Enterprise PDM. The body of the paper deals with a new range of air circuit breakers ABB SACE Emax 2 and their implementation into the product line of low voltage switchgears. Included are other improvements that together with implementation of circuit breakers AGOMIN project brings.
6

Simulace přestupu tepla v nízkonapěťovém rozváděči MNS / Simulation of Heat Transfer in Low-Voltage Switchboard MNS - Optimization of Heat Transfer into The Switchboard

Czudek, Aleš January 2015 (has links)
The thesis includes diagnostics temperature field of industrial low voltage. Place of origin, flow and heat transfer are important aspects in the design of the switchgear, especially in terms of proper equipment layout. The correctness of the design of the switchgear is verified by measuring the practical temperature field during testing or in work mode. To determine the temperature profile, it is necessary to measure the temperature at various points of the switchgear, either contact or contactless method. Measurements are performed on standardized low voltage switchboards, which are located power elements. The goal is to replace costly and time-consuming field testing switchgear efficient simulation of the temperature field mathematical model developed switchboards.

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