Bestimmung der kinetischen Zerfallskonstanten und der kinetischen Bildungskonstanten ausgewählter MRT-Kontrastmittel

Im Rahmen dieser Arbeit wurde eine Bestimmung der kinetischen Bildungskonstanten von Komplexen GdDTPA (Gadolinium-Diethylentriaminpentaessigsäure) und GdDOTA (Gadolinium-1,4,7,10-Tetraazacyclododecan-1,4,7,10-tetraessigsäure) bei 25 °C mit einer Gadolinium(III)-sensitiven Elektrode durchgeführt. Weiterhin wurde der Zerfall der Komplexe GdDTPA, GdDOTA, Gd-BT-DO3A (Gadolinium4-[(4-benzothiazol-2-yl-phenylcarbamoyl)-methyl]-7,10-bis-carboxymethyl-1,4,7,10-tetraazacyc-lododec-1-yl}-essigsäure) und Gd-HP-DO3A (Gadolinium-2-[4,7-bis(carboxylatomethyl)-10-(2-hydroxypropyl)-1,4,7,10-tetrazacyclododec-1-yl]acetat) bei 25 °C und 37 °C mit der pH-Stat Methode untersucht. Mit Ausnahme von GdDTPA sind die untersuchten Komplexe momentan als MRT-Kontrastmittel für den Markt zugelassen. Hierbei fand eine Validierung der verwendeten Methoden zur Bestimmung der Bildungs- und Zerfallskonstanten statt. Dabei konnte der Arbeitsbereich und Limitierung der verwendeten Methoden gezeigt werden. Die Bestimmung der Zerfallskonstanten von GdDTPA und GdDOTA war mit der pH-Stat Methode nicht möglich. Zerfallskonstanten dieser Komplexe liegen außerhalb des Arbeitsbereiches von der pH-Stat Methode. Der Zerfall von Gd-BT-DO3A und Gd-HP-DO3A verläuft säurekatalysiert, wobei der Komplex Gd-HP-BT-DO3A bei vergleichbaren Bedingungen langsamer zerfällt als Gd-HP-DO3A. Sowohl bei 25 °C als auch bei 37 °C werden die Komplexe Gd-BT-DO3A und HP-DO3A zunächst protoniert, anschließend zerfallen die monoprotonierten Komplexe. Die Bildung vom Komplex GdDTPA im Bereich zwischen pH 4,2 und pH 4,8 verläuft basenkatalysiert, die Bildungsgeschwindigkeit wird mit einem steigendem pH-Wert größer. Der Komplex GdDOTA wird bei pH 7,4 und 25 °C langsamer gebildet als GdDTPA bei pH 4,8 und 25 °C.The purpose of this thesis is a determination of the kinetic formation constants from the complexes GdDTPA (Gadolinium-diethylenetriaminepentaacetic acid) and GdDOTA (Gadolinium-1,4,7,10-Tetraazacyclododecane-1,4,7,10-tetraacetic acid) with a Gadolinium(III)-sensitive electrode. Furthermore, the decay of the complexes GdDTPA, GdDOTA, Gd-BT-DO3A (Gadolinium-4-[(4-benzothiazol-2-yl-phenylcarbamoyl)-methyl]-7,10-bis-carboxymethyl-1,4,7,10-tetraazacyclododec-1-yl} acetic acid) and Gd-HP-DO3A (Gadolinium-1,4,7-triscarboxymethyl-1,4,7,10-tetraazacyclododecane) at 25 °C and 37 °C was investigated with the pH-Stat method. Withe the exception of GdDTPA, these complexes are used as MRI contrast agents. Methods for determination of the formation and decay constants, have been validated, so the work area and limitation of the methods could be shown. It was not possible to investigate the decay of the complexes GdDTPA and GdDOTA with the pH-Stat method. Decay constants of these complexes at 25 °C are outside the working range of the pH-Stat method. The decay of Gd-BT-DO3A and Gd-HP-DO3A is acid-catalyzed. Under comparable conditions the complex Gd-HP-BT-DO3A decays more slowly than Gd-HP-DO3A. During the decay of Gd-BT-DO3A and HP-DO3A at 25 °C and 37 °C a protonation of the complexes takes place. After the protonation, in a second reaction step the monoprotonated Gd3+ complexes decay. The formation of GdDOTA and GdDTPA is base catalyzed. Due to structural differences between the ligands DOTA and DTPA, the formation of the complex GdDTPA is faster than the formation of GdDOTA

CENTRIFUGAL LABTUBE FOR FULLY AUTOMATED DNA EXTRACTION & LAMP AMPLIFICATION BASED ON AN INTEGRATED, LOW-COST HEATING SYSTEM

In this paper, we introduce a disposable battery-driven heating system for loop-mediated isothermal DNA amplification (LAMP) inside a centrifugally-driven DNA-extraction platform (LabTube). We demonstrate fully automated, fully closed extraction of as little as 100 DNA copies of verotoxin-producing (VTEC) Escherichia coli lysate in water, milk and apple juice in a standard laboratory centrifuge, followed by subsequent automatic LAMP amplification with an overall time-to-result of 1.5hrs. The system is disposable, fully closed and automated, requiring only a single pipetting step. The microcontroller-driven heating system is low-cost (<1$) and it can be easily parallelized. Because the heated LabSystem runs within a standard laboratory centrifuge, it is suitable for DNA extraction and amplification in low-resource areas, at production sites or sales locations

Focus: Implementing participation - Advancement of social services in analog and digital spaces

Digitale Informations- und Kommunikationstechnologien gewinnen als fester Bestandteil zunehmend Bedeutung in den alltäglichen Lebenswelten einer wachsenden Zahl von Menschen. Ihre Entwicklung und selbstverständliche Nutzung schreiten in einem immer rasanteren Tempo voran; die vielfältigen Anwendungsmöglichkeiten adressieren längst alle Lebensbereiche. Während der Digitalisierung von Kommunikationsprozessen zuweilen demokratisierende Kräfte zugesprochen werden, scheint eine kritische Reflexion möglicher Potentiale und Auswirkungen digitaler Informations- und Kommunikationstechnologien auf Teilhabedynamiken in unterschiedlichen Lebensbereichen dringend erforderlich. Die Autorinnen und Autoren möchten mit dieser SI:SO-Schwerpunktausgabe einen Beitrag zu einer kritischen Reflexion digitaler Innovationen und ihrer Auswirkungen auf die zukünftige Gestaltung sozialer Dienste leisten. Mit der zweisprachigen Ausgabe ist zudem die Hoffnung verbunden, diesen Beitrag auch einem europäischen und weltweiten Publikum zugänglich zu machen.Digital information and communications technologies are becoming an increasingly important part in everyday life of a growing number of people. Their development and natural use are progressing even faster with a wide range of possible applications addressing all areas of life. While the digitization of communication processes is sometimes said to have democratizing forces, critical reflection on the potential and impact of digital information and communication technologies on participation dynamics in different areas of life seems urgently needed. The Authors would like to contribute to a critical reflection on digital innovations and their impact on the future design of social services. The bilingual edition further aims to make this contribution accessible to a European and global audience

Collaborative Speculations on Future Themes for Participatory Design in Germany

Participatory Design means recognizing that those who will be affected by a future technology should have an active say in its creation. Yet, despite continuous interest in involving people as future users and consumers into designing novel and innovative future technology, participatory approaches in technology design remain relatively underdeveloped in the German HCI community. This article brings together the diversity of voices, domains, perspectives, approaches, and methods that collectively shape Participatory Design in Germany. In the following, we (1) outline our understanding of participatory practice and how it is different from mere user involvement; (2) reflect current issues of participatory and fair technology design within the German Participatory Design community; and (3) discuss tensions relevant to the field, that we expect to arise in the future, and which we derived from our 2021 workshop through a speculative method. We contribute an introduction and an overview of current themes and a speculative outlook on future issues of Participatory Design in Germany. It is meant to inform, provoke, inspire and, ultimately, invite participation within the wider Computer Science community

Encyclopédie des historiographies : Afriques, Amériques, Asies

Quels rapports les sociétés humaines entretiennent-elles avec leur passé et quels récits font-elles du temps révolu ? Pour ce premier volume de l’Encyclopédie des historiographies. Afriques, Amériques, Asies, 157 spécialistes représentant 88 institutions académiques en France et dans le monde explorent l’univers des productions humaines qui constituent des sources pour l’historien et déchiffrent les nombreuses modalités (« scientifiques », littéraires, artistiques, monumentales…) de l’écriture du passé. Évoquant tour à tour l’Afrique, l’Amérique latine, l’Asie, l’Océanie, les 216 notices de l’ouvrage présentent des matériaux historiques de toute nature, issus de toutes les époques, souvent méconnus, ainsi que l’histoire de leurs usages. L’entreprise collective qu’est l’Encyclopédie se veut novatrice : il s’agit de susciter une réflexion historiographique résolument non-occidentalo-centrée qui complète utilement les démarches épistémologiques traditionnelles. Nouvel outil de connaissance historique forgé à l’heure de la mondialisation, l’Encyclopédie des historiographies est aussi une véritable invitation au voyage.What are the different types of relations that non-Western societies upkeep with their past and how are narratives about the past produced by them? In this first volume of the Encyclopaedia of Historiography: Africa, America, Asia, 157 specialists from 88 international academic institutions explore the wealth of evidence that constitutes source material for historians. They also examine the immensely diverse modes or genres of narrated history: “scientific”, literary, artistic, architectural, etc. 216 entries dealing with Africa, Latin America, Oceania, and Asia, cover a large variety of sources, including many which are unfamiliar to the Western or non-Western reader, along with the history of how they have been exploited. By bringing together for the first time such an abundance of material the reader is offered the possibility of exploring continents and building meaningful connections across space and time. In addition to being a new tool for historical enquiry in an era of globalization, this encyclopaedia is also an invitation to travel the world

ACC/AHA 2006 Practice Guidelines for the Management of Patients With Valvular Heart Disease: Executive Summary. A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise t

"The ACC and the AHA have long been involved in the joint development of practice guidelines designed to assist healthcare providers in the management of selected cardiovascular disorders or the selection of certain cardiovascular procedures. The determination of the disorders or procedures to develop guidelines for is based on several factors, including importance to healthcare providers and whether there are sufficient data from which to derive accepted guidelines. One important category of cardiac disorders that affect a large number of patients who require diagnostic procedures and decisions regarding long-term management is valvular heart disease. During the past 2 decades, major advances have occurred in diagnostic techniques, the understanding of natural history, and interventional cardiology and surgical procedures for patients with valvular heart disease. These advances have resulted in enhanced diagnosis, more scientific selection of patients for surgery or catheter-based intervention versus medical management, and increased survival of patients with these disorders. The information base from which to make clinical management decisions has greatly expanded in recent years, yet in many situations, management issues remain controversial or uncertain. Unlike many other forms of cardiovascular disease, there is a scarcity of large-scale multicenter trials addressing the diagnosis and treatment of patients with valvular disease from which to derive definitive conclusions, and the information available in the literature represents primarily the experiences reported by single institutions in relatively small numbers of patients.