Antecedents of Trust: Status and Power in Virtual Teams

Few empirical efforts have been made to observe hierarchical elements of leadership, namely status and power distinctively. Virtual teams as a form of geographically dispersed work arrangement offer significant opportunities for companies and organizations around the globe, but also pose additional challenges to the leadership and the team itself. Due to communication challenges status and power have special characteristics in virtual teams compared to traditional teams. In this investigation we examine how status and power of a leader impact trust building in virtual teams and in turn the team’s performance. The results revealed that status of a leader has a positive influence on trust in the leader, while power of a leader had no unique effect on followers’ reactions. As members of diverse cultures have different perceptions of leaders, we found a moderating effect of culture but not for team size

The Role of Culture and Personality in the Leadership Process in Virtual Teams

Leadership is a key challenge of virtual teams. A particular leadership style, namely inspirational leadership, which is a sub-category of transformational leadership, has been found to be especially suited for the study of highly diverse teams. Virtual team leaders increasingly have to manage global virtual teams that contain members from different cultural backgrounds and value orientations. This study answers a call of incorporating the role of individual-level attributes and dispositions as moderators of inspirational leadership effects, considering cultural and individual values of followers in a virtual setting. Results reveal the importance of inspirational leadership influencing attitudinal outcomes (trust in leadership and cohesion). Furthermore, the effect of leadership is shown to be dependent on cultural as well as personal values of followers indicating the need to consider individual factors in the process of managing virtual teams

Conflict, Value Diversity, and Performance in Virtual Teams

While most studies investigating culture in the context of conflict in teams have been using culture dimensions such as collectivism this study centers on another measurement of culture, namely individual values. In this investigation we examined how individual value diversity influences the relationship between team conflict and performance in virtual teams. Assessing two types of conflict, namely task and process conflict, the results revealed that task conflict had no unique effect beyond the impact of process conflict. Contrary to previous findings relating to group culture, this study found that value diversity has no influence on the relationship between conflict and performance in virtual teams. While individuals come to groups with their own values, they may be less powerful predictors of their behavior in groups where there are strong prevailing group values and norms to act a certain way

Domestic violence victims in a hospital setting:prevalence, health impact and patients' preferences - results from a cross-sectional study

Background: Domestic violence (DV) is a widespread yet commonly underdetected problem with severe impact on physical and mental health. To date, only limited information is available on prevalence and detection-rates of victims of DV in hospital settings. Objective: The aim of this study was (a) to assess the prevalence and impact of DV on physical and mental health as well as risk-factors associated with it, (b) to determine how many patients had been asked directly about DV in the hospital and (c) to investigate patients' preferences about being asked about DV in a hospital setting. Methods: Adult inpatients and outpatients at seven somatic departments at the University Hospital Innsbruck (Austria) were included consecutively in this ad-hoc, cross-sectional paper-and-pencil questionnaire-based study. In total, n = 2,031 patients were assessed regarding their experiences with DV. They also reported on whether they had been asked about DV at the hospital and whether they would mind being asked about it. To evaluate the impact of DV on patients' self-reported physical and mental health, odds ratios were calculated using binary logistic regression. Results: DV was reported by 17.4% of patients, with 4.0% indicating current DV exposure. Lifetime DV exposure was associated with a significant risk for both physical and mental health-problems. Only 4.8% of patients with DV exposure had ever been asked about it by hospital staff. While patients with a history of DV were more open to being asked about DV than patients without DV (78.2% vs. 72.9%), overall acceptance was still high (74%). Conclusion: DV is a frequently overlooked problem with detrimental effects on physical and mental health. While high acceptance of DV assessment was found, only a small proportion of affected patients had indeed been assessed for DV. Screening for DV in hospitals may thus increase the number of identified patients

Human Practice. Digital Ecologies. Our Future. : 14. Internationale Tagung Wirtschaftsinformatik (WI 2019) : Tagungsband

Erschienen bei: universi - Universitätsverlag Siegen. - ISBN: 978-3-96182-063-4Aus dem Inhalt: Track 1: Produktion & Cyber-Physische Systeme Requirements and a Meta Model for Exchanging Additive Manufacturing Capacities Service Systems, Smart Service Systems and Cyber- Physical Systems—What’s the difference? Towards a Unified Terminology Developing an Industrial IoT Platform – Trade-off between Horizontal and Vertical Approaches Machine Learning und Complex Event Processing: Effiziente Echtzeitauswertung am Beispiel Smart Factory Sensor retrofit for a coffee machine as condition monitoring and predictive maintenance use case Stakeholder-Analyse zum Einsatz IIoT-basierter Frischeinformationen in der Lebensmittelindustrie Towards a Framework for Predictive Maintenance Strategies in Mechanical Engineering - A Method-Oriented Literature Analysis Development of a matching platform for the requirement-oriented selection of cyber physical systems for SMEs Track 2: Logistic Analytics An Empirical Study of Customers’ Behavioral Intention to Use Ridepooling Services – An Extension of the Technology Acceptance Model Modeling Delay Propagation and Transmission in Railway Networks What is the impact of company specific adjustments on the acceptance and diffusion of logistic standards? Robust Route Planning in Intermodal Urban Traffic Track 3: Unternehmensmodellierung & Informationssystemgestaltung (Enterprise Modelling & Information Systems Design) Work System Modeling Method with Different Levels of Specificity and Rigor for Different Stakeholder Purposes Resolving Inconsistencies in Declarative Process Models based on Culpability Measurement Strategic Analysis in the Realm of Enterprise Modeling – On the Example of Blockchain-Based Initiatives for the Electricity Sector Zwischenbetriebliche Integration in der Möbelbranche: Konfigurationen und Einflussfaktoren Novices’ Quality Perceptions and the Acceptance of Process Modeling Grammars Entwicklung einer Definition für Social Business Objects (SBO) zur Modellierung von Unternehmensinformationen Designing a Reference Model for Digital Product Configurators Terminology for Evolving Design Artifacts Business Role-Object Specification: A Language for Behavior-aware Structural Modeling of Business Objects Generating Smart Glasses-based Information Systems with BPMN4SGA: A BPMN Extension for Smart Glasses Applications Using Blockchain in Peer-to-Peer Carsharing to Build Trust in the Sharing Economy Testing in Big Data: An Architecture Pattern for a Development Environment for Innovative, Integrated and Robust Applications Track 4: Lern- und Wissensmanagement (e-Learning and Knowledge Management) eGovernment Competences revisited – A Literature Review on necessary Competences in a Digitalized Public Sector Say Hello to Your New Automated Tutor – A Structured Literature Review on Pedagogical Conversational Agents Teaching the Digital Transformation of Business Processes: Design of a Simulation Game for Information Systems Education Conceptualizing Immersion for Individual Learning in Virtual Reality Designing a Flipped Classroom Course – a Process Model The Influence of Risk-Taking on Knowledge Exchange and Combination Gamified Feedback durch Avatare im Mobile Learning Alexa, Can You Help Me Solve That Problem? - Understanding the Value of Smart Personal Assistants as Tutors for Complex Problem Tasks Track 5: Data Science & Business Analytics Matching with Bundle Preferences: Tradeoff between Fairness and Truthfulness Applied image recognition: guidelines for using deep learning models in practice Yield Prognosis for the Agrarian Management of Vineyards using Deep Learning for Object Counting Reading Between the Lines of Qualitative Data – How to Detect Hidden Structure Based on Codes Online Auctions with Dual-Threshold Algorithms: An Experimental Study and Practical Evaluation Design Features of Non-Financial Reward Programs for Online Reviews: Evaluation based on Google Maps Data Topic Embeddings – A New Approach to Classify Very Short Documents Based on Predefined Topics Leveraging Unstructured Image Data for Product Quality Improvement Decision Support for Real Estate Investors: Improving Real Estate Valuation with 3D City Models and Points of Interest Knowledge Discovery from CVs: A Topic Modeling Procedure Online Product Descriptions – Boost for your Sales? Entscheidungsunterstützung durch historienbasierte Dienstreihenfolgeplanung mit Pattern A Semi-Automated Approach for Generating Online Review Templates Machine Learning goes Measure Management: Leveraging Anomaly Detection and Parts Search to Improve Product-Cost Optimization Bedeutung von Predictive Analytics für den theoretischen Erkenntnisgewinn in der IS-Forschung Track 6: Digitale Transformation und Dienstleistungen Heuristic Theorizing in Software Development: Deriving Design Principles for Smart Glasses-based Systems Mirroring E-service for Brick and Mortar Retail: An Assessment and Survey Taxonomy of Digital Platforms: A Platform Architecture Perspective Value of Star Players in the Digital Age Local Shopping Platforms – Harnessing Locational Advantages for the Digital Transformation of Local Retail Outlets: A Content Analysis A Socio-Technical Approach to Manage Analytics-as-a-Service – Results of an Action Design Research Project Characterizing Approaches to Digital Transformation: Development of a Taxonomy of Digital Units Expectations vs. Reality – Benefits of Smart Services in the Field of Tension between Industry and Science Innovation Networks and Digital Innovation: How Organizations Use Innovation Networks in a Digitized Environment Characterising Social Reading Platforms— A Taxonomy-Based Approach to Structure the Field Less Complex than Expected – What Really Drives IT Consulting Value Modularity Canvas – A Framework for Visualizing Potentials of Service Modularity Towards a Conceptualization of Capabilities for Innovating Business Models in the Industrial Internet of Things A Taxonomy of Barriers to Digital Transformation Ambidexterity in Service Innovation Research: A Systematic Literature Review Design and success factors of an online solution for cross-pillar pension information Track 7: IT-Management und -Strategie A Frugal Support Structure for New Software Implementations in SMEs How to Structure a Company-wide Adoption of Big Data Analytics The Changing Roles of Innovation Actors and Organizational Antecedents in the Digital Age Bewertung des Kundennutzens von Chatbots für den Einsatz im Servicedesk Understanding the Benefits of Agile Software Development in Regulated Environments Are Employees Following the Rules? On the Effectiveness of IT Consumerization Policies Agile and Attached: The Impact of Agile Practices on Agile Team Members’ Affective Organisational Commitment The Complexity Trap – Limits of IT Flexibility for Supporting Organizational Agility in Decentralized Organizations Platform Openness: A Systematic Literature Review and Avenues for Future Research Competence, Fashion and the Case of Blockchain The Digital Platform Otto.de: A Case Study of Growth, Complexity, and Generativity Track 8: eHealth & alternde Gesellschaft Security and Privacy of Personal Health Records in Cloud Computing Environments – An Experimental Exploration of the Impact of Storage Solutions and Data Breaches Patientenintegration durch Pfadsysteme Digitalisierung in der Stressprävention – eine qualitative Interviewstudie zu Nutzenpotenzialen User Dynamics in Mental Health Forums – A Sentiment Analysis Perspective Intent and the Use of Wearables in the Workplace – A Model Development Understanding Patient Pathways in the Context of Integrated Health Care Services - Implications from a Scoping Review Understanding the Habitual Use of Wearable Activity Trackers On the Fit in Fitness Apps: Studying the Interaction of Motivational Affordances and Users’ Goal Orientations in Affecting the Benefits Gained Gamification in Health Behavior Change Support Systems - A Synthesis of Unintended Side Effects Investigating the Influence of Information Incongruity on Trust-Relations within Trilateral Healthcare Settings Track 9: Krisen- und Kontinuitätsmanagement Potentiale von IKT beim Ausfall kritischer Infrastrukturen: Erwartungen, Informationsgewinnung und Mediennutzung der Zivilbevölkerung in Deutschland Fake News Perception in Germany: A Representative Study of People’s Attitudes and Approaches to Counteract Disinformation Analyzing the Potential of Graphical Building Information for Fire Emergency Responses: Findings from a Controlled Experiment Track 10: Human-Computer Interaction Towards a Taxonomy of Platforms for Conversational Agent Design Measuring Service Encounter Satisfaction with Customer Service Chatbots using Sentiment Analysis Self-Tracking and Gamification: Analyzing the Interplay of Motivations, Usage and Motivation Fulfillment Erfolgsfaktoren von Augmented-Reality-Applikationen: Analyse von Nutzerrezensionen mit dem Review-Mining-Verfahren Designing Dynamic Decision Support for Electronic Requirements Negotiations Who is Stressed by Using ICTs? A Qualitative Comparison Analysis with the Big Five Personality Traits to Understand Technostress Walking the Middle Path: How Medium Trade-Off Exposure Leads to Higher Consumer Satisfaction in Recommender Agents Theory-Based Affordances of Utilitarian, Hedonic and Dual-Purposed Technologies: A Literature Review Eliciting Customer Preferences for Shopping Companion Apps: A Service Quality Approach The Role of Early User Participation in Discovering Software – A Case Study from the Context of Smart Glasses The Fluidity of the Self-Concept as a Framework to Explain the Motivation to Play Video Games Heart over Heels? An Empirical Analysis of the Relationship between Emotions and Review Helpfulness for Experience and Credence Goods Track 11: Information Security and Information Privacy Unfolding Concerns about Augmented Reality Technologies: A Qualitative Analysis of User Perceptions To (Psychologically) Own Data is to Protect Data: How Psychological Ownership Determines Protective Behavior in a Work and Private Context Understanding Data Protection Regulations from a Data Management Perspective: A Capability-Based Approach to EU-GDPR On the Difficulties of Incentivizing Online Privacy through Transparency: A Qualitative Survey of the German Health Insurance Market What is Your Selfie Worth? A Field Study on Individuals’ Valuation of Personal Data Justification of Mass Surveillance: A Quantitative Study An Exploratory Study of Risk Perception for Data Disclosure to a Network of Firms Track 12: Umweltinformatik und nachhaltiges Wirtschaften Kommunikationsfäden im Nadelöhr – Fachliche Prozessmodellierung der Nachhaltigkeitskommunikation am Kapitalmarkt Potentiale und Herausforderungen der Materialflusskostenrechnung Computing Incentives for User-Based Relocation in Carsharing Sustainability’s Coming Home: Preliminary Design Principles for the Sustainable Smart District Substitution of hazardous chemical substances using Deep Learning and t-SNE A Hierarchy of DSMLs in Support of Product Life-Cycle Assessment A Survey of Smart Energy Services for Private Households Door-to-Door Mobility Integrators as Keystone Organizations of Smart Ecosystems: Resources and Value Co-Creation – A Literature Review Ein Entscheidungsunterstützungssystem zur ökonomischen Bewertung von Mieterstrom auf Basis der Clusteranalyse Discovering Blockchain for Sustainable Product-Service Systems to enhance the Circular Economy Digitale Rückverfolgbarkeit von Lebensmitteln: Eine verbraucherinformatische Studie Umweltbewusstsein durch audiovisuelles Content Marketing? Eine experimentelle Untersuchung zur Konsumentenbewertung nachhaltiger Smartphones Towards Predictive Energy Management in Information Systems: A Research Proposal A Web Browser-Based Application for Processing and Analyzing Material Flow Models using the MFCA Methodology Track 13: Digital Work - Social, mobile, smart On Conversational Agents in Information Systems Research: Analyzing the Past to Guide Future Work The Potential of Augmented Reality for Improving Occupational First Aid Prevent a Vicious Circle! The Role of Organizational IT-Capability in Attracting IT-affine Applicants Good, Bad, or Both? Conceptualization and Measurement of Ambivalent User Attitudes Towards AI A Case Study on Cross-Hierarchical Communication in Digital Work Environments ‘Show Me Your People Skills’ - Employing CEO Branding for Corporate Reputation Management in Social Media A Multiorganisational Study of the Drivers and Barriers of Enterprise Collaboration Systems-Enabled Change The More the Merrier? The Effect of Size of Core Team Subgroups on Success of Open Source Projects The Impact of Anthropomorphic and Functional Chatbot Design Features in Enterprise Collaboration Systems on User Acceptance Digital Feedback for Digital Work? Affordances and Constraints of a Feedback App at InsurCorp The Effect of Marker-less Augmented Reality on Task and Learning Performance Antecedents for Cyberloafing – A Literature Review Internal Crowd Work as a Source of Empowerment - An Empirical Analysis of the Perception of Employees in a Crowdtesting Project Track 14: Geschäftsmodelle und digitales Unternehmertum Dividing the ICO Jungle: Extracting and Evaluating Design Archetypes Capturing Value from Data: Exploring Factors Influencing Revenue Model Design for Data-Driven Services Understanding the Role of Data for Innovating Business Models: A System Dynamics Perspective Business Model Innovation and Stakeholder: Exploring Mechanisms and Outcomes of Value Creation and Destruction Business Models for Internet of Things Platforms: Empirical Development of a Taxonomy and Archetypes Revitalizing established Industrial Companies: State of the Art and Success Principles of Digital Corporate Incubators When 1+1 is Greater than 2: Concurrence of Additional Digital and Established Business Models within Companies Special Track 1: Student Track Investigating Personalized Price Discrimination of Textile-, Electronics- and General Stores in German Online Retail From Facets to a Universal Definition – An Analysis of IoT Usage in Retail Is the Technostress Creators Inventory Still an Up-To-Date Measurement Instrument? Results of a Large-Scale Interview Study Application of Media Synchronicity Theory to Creative Tasks in Virtual Teams Using the Example of Design Thinking TrustyTweet: An Indicator-based Browser-Plugin to Assist Users in Dealing with Fake News on Twitter Application of Process Mining Techniques to Support Maintenance-Related Objectives How Voice Can Change Customer Satisfaction: A Comparative Analysis between E-Commerce and Voice Commerce Business Process Compliance and Blockchain: How Does the Ethereum Blockchain Address Challenges of Business Process Compliance? Improving Business Model Configuration through a Question-based Approach The Influence of Situational Factors and Gamification on Intrinsic Motivation and Learning Evaluation von ITSM-Tools für Integration und Management von Cloud-Diensten am Beispiel von ServiceNow How Software Promotes the Integration of Sustainability in Business Process Management Criteria Catalog for Industrial IoT Platforms from the Perspective of the Machine Tool Industry Special Track 3: Demos & Prototyping Privacy-friendly User Location Tracking with Smart Devices: The BeaT Prototype Application-oriented robotics in nursing homes Augmented Reality for Set-up Processe Mixed Reality for supporting Remote-Meetings Gamification zur Motivationssteigerung von Werkern bei der Betriebsdatenerfassung Automatically Extracting and Analyzing Customer Needs from Twitter: A “Needmining” Prototype GaNEsHA: Opportunities for Sustainable Transportation in Smart Cities TUCANA: A platform for using local processing power of edge devices for building data-driven services Demonstrator zur Beschreibung und Visualisierung einer kritischen Infrastruktur Entwicklung einer alltagsnahen persuasiven App zur Bewegungsmotivation für ältere Nutzerinnen und Nutzer A browser-based modeling tool for studying the learning of conceptual modeling based on a multi-modal data collection approach Exergames & Dementia: An interactive System for People with Dementia and their Care-Network Workshops Workshop Ethics and Morality in Business Informatics (Workshop Ethik und Moral in der Wirtschaftsinformatik – EMoWI’19) Model-Based Compliance in Information Systems - Foundations, Case Description and Data Set of the MobIS-Challenge for Students and Doctoral Candidates Report of the Workshop on Concepts and Methods of Identifying Digital Potentials in Information Management Control of Systemic Risks in Global Networks - A Grand Challenge to Information Systems Research Die Mitarbeiter von morgen - Kompetenzen künftiger Mitarbeiter im Bereich Business Analytics Digitaler Konsum: Herausforderungen und Chancen der Verbraucherinformati

Synthese von Azidozuckern ausgehend von Weinsäure

2-Azidozucker bilden eine interessante Ausgangsverbindung für die Synthese von 2-Aminozucker. In dieser Arbeit wird eine einheitliche Synthese präsentiert, mit der beide Konformationen des Galactose-, als auch das Idosederivat hergestellt werden können. Mit der günstig erwerblichen D- bzw. L-Weinsäure als Startmaterial, waren bereits die stereogenen Zentren des C-4 und C-5 gegeben. Syntheseroute I bestand darin nach der Veresterung und Acetalisierung der Hydroxyfunktionen, die Esterfunktionen mit LiAlH4 zu reduzieren und anschließende eine Monobenzylierung durchzuführen. Anschließend konnte die freie Alkoholfunktion zum Aldehyd oxidiert werden. Nach einer In-unterstützten Allylierung wurde durch Ozonolyse ein Aldehyd generiert. Anschließende Acetylierung und Eliminierung der, bei der Allylierung enstandenen OH-Gruppe, führte zur Bildung eines ungesättigten Aldehyds. Hierbei kam es jedoch zur Isomerisierung am C-4, weshalb Syntheseroute II ausgearbeitet wurde. Bei dieser wurde nach der Acetylierung und Veresterung der Weinsäure mit DIBAL asymmetrisch reduziert, um an der einen Seite einen Alkohol und an der anderen einen Aldehyd zu erhalten, welcher in einer „Eintopf“-Reaktion über die Horner-Wadsworth-Emmons-Reaktion zum ungesättigten Ester umgesetzt wurde. Nach der Schützung der freien OH-Gruppe wurde der Ester mit DIBAL zum Alkohol reduziert. Nun wurde über die stereoselektive Sharpless-Epoxidierung mit L- oder D Diethyltartrat (DET) ein Sauerstoff eingeführt. An dieser Stelle wurde die Isomerie (Azidogalactose oder –idose) entschieden. Um das Epoxid anschließend mittels TMSN3 und Pd(PPh3)4 stereo- und regioselektiv zu öffnen und ein Azid am C-2 einzuführen, musste zuvor der Alkohol zum Aldehyd oxidiert und über eine Wittig-Reaktion ein ungesättigter Ester gebildet werden. Zum Schluss wurden die Hydroxyruppen mit AcCl/MeOH entschützt und eine Ozonolyse des Esters durchgeführt, um den gewünschten Azidozucker zu erhalten

Contributions toward the synthesis of bioactive compounds

Diese Dissertation setzt sich aus zwei Projekten zusammen. Das erste Projekt umfasst einen flexiblen, synthetischen Zugang zu N-Acetylgalaktosamin (GalNAc) and N-Acetylidosamin (IdoNAc). GalNAc, als Teil von Glykoproteinen, kann in einer Vielzahl von Wirbeltieren, Säugetieren und Pflanzen gefunden werden. Es dient als Verbindung zwischen Proteinen deren Saccharidketten. Diese Proteine sind bekannt für ihre zentrale Rolle in den unterschiedlichsten Rezeptorprozessen und Zell-Zell-Interaktionen. Daher ist es von großem Interesse einen synthetischen Zugang zu diesen Verbindungen zu finden. Wir haben eine neue Synthese für GalNAc entwickelt, die von der Weinsäure ausgeht, da diese Verbindung bereits zwei der vier notwendigen stereogenen Zentren besitzt. In dieser Synthese wird das Kohlenhydratrückrad via Horner-Wadsworth-Emmons-Verlängerung (HWE-Verlängerung) eines zuvor oxidierten Threitols aufgebaut. Nachdem diese Verbindung reduziert wurde, wird die Sauerstofffunktion via Sharpless-Epoxidierung eingeführt. Eine weitere Oxidation-HWE-Sequenz macht eine Epoxidierung unter Tsuji-Trost-Bedingungen möglich, die zu einer nukleophilen Substitution eines Azids führt. Diese Vorgehensweise ermöglicht die stereo- und regioselektive Einführung einer Sauerstoff- und Stickstoff-Funktion. Weiters zeigt dieser Zugang eine hohe Flexibilität, da die Synthese von vier verschiedenen Kohlenhydratisomeren möglich ist. Es wurde nicht nur das D-, sondern auch das L-konfigurierte GalNAc synthetisiert. Als konzeptioneller Beweis wurde zusätzlich das peracetylierte L-IdoNAc hergestellt. Das zweite Projekt umfasst einen synthetischen Zugang zu Ulosonsäure-Bioisosteren. Ulosonsäuren sind eine wichtige Gruppe der Kohlenhydrate, zu der bekannte Stellvertreter wie 3 Deoxy α D-manno-oct-2-ulosonsäure (Kdo), 2-Keto-3-deoxy-D-glycero-D-galactononsäure (Kdn) and N-Acetylneuraminsäure (Neu5Ac) gehören. Als Teil von Lipopolysacchariden (LPS) und Kapselpolysacchariden (CPS, K-Antigene) findet man diese Kohlenhydrate auf jeder Bakterienoberfläche. Wir haben einen synthetischen Zugang zu Tetrazolderivaten dieser Verbindung entwickelt. Tetrazole sind die idealen bioisosterischen Analoga für Carbonsäuren in der Medikamentenentwicklung, da sie deren metabolischen Eigenschaften positiv beeinflussen. Die hier vorgestellte Route beinhaltet eine Indium-mediierte Allylierung mit anschließender [2 + 3] Cycloaddition als Schlüsselschritte. Nach einer anschließenden Ozonolyse wurde so Tetrazol-Kdo und sein C-4-Epimer hergestellt. Dieser Ansatz ist flexibel genug, um für die Herstellung weiteren Tetrazol-Bioisosteren von Ulosonsäuren, wie N-Acetylneuraminsäure (Neu5Ac) oder 3 Desoxy-D-arabino-heptulosonsäure adaptiert werden zu können.This thesis consists of two projects. The first project comprises a flexible synthetic access towards N-acetylgalactosamine (GalNAc) and N-acetylidosamine (IdoNAc). GalNAc, as part of glycoproteins, can be found in a wide range of invertebrates, mammals and plants. It serves as link between the saccharide chain and the protein moiety. These proteins are known for their pivotal role in different receptor processes and cell-cell-interactions. Hence, a synthetical access towards this compound have been attracting a lot of interest. We have developed a novel route towards GalNAc, starting from the non-carbohydrate compound tartaric acid. This compound already provides two of the four desired stereogenic centers. In this synthesis, the carbohydrate backbone is build up via Horner-Wadsworth-Emmons (HWE) elongation of a previously oxidized threitol. After the compound is reduced, the oxygen moiety is introduced via Sharpless epoxidation. Another oxidation-HWE sequence paves the way for the Tsuji-Trost type epoxide opening, leading to a nucleophilic substitution of an azide. Taken together, this approach enables the establishment of the desired oxygen and nitrogen functions, both stereo- and regioselective. Furthermore, it shows an advantageous flexibility as it enables the synthesis of four different carbohydrate isomers. Not only was the D configuration of GalNAc synthesized, but also the unnatural L configuration. In addition, the D configuration of the peracetylated IdoNAc was prepared as a proof of concept. The second project comprises a concise synthetic route towards ulosonic acid bioisosteres. Ulosonic acids are an important class of carbohydrates, including well known representatives as 3 deoxy α D-manno-oct-2-ulosonic acid (Kdo), 2-keto-3-deoxy-D-glycero-D-galactononic acid (Kdn) and N-acetylneuraminic acid (Neu5Ac). As part of the lipopolysaccharides (LPS) and capsular polysaccharides (CPS, K-antigen), these carbohydrates can be found on entirely all bacteria surfaces. We have developed a synthetic approach to access tetrazole derivatives of these compounds. Tetrazoles have shown to be ideal analogues for the bioisosteric replacement of carboxylic acids in several drugs, positively influencing their metabolic properties. The presented route features indium-mediated allylation with subsequent [2 + 3]-cycloaddition as key steps. After ozonolysis, this route leads to the tetrazole derivative of Kdo and its corresponding C-4 epimer. The route is flexible enough to be adapted to the preparation of further tetrazole bioisosteres of ulosonic acids as N acetylneuraminic acid or 3-deoxy-D-arabino-heptulosonic acid

Systematisch statt zufällig : wie Wissensarbeiter produktiver werden

Die Autorinnen schildern, wie Mittels der Potenzialanalyse Wissen und Produktivität anhand der Regelsysteme festgestellt wird, wo Defizite im systematischen Umgang mit Wissen liegen. Darauf basierend können gezielte organisatorische Verbesserungsmaßnahmen gesetzt werden.Informationstechnologie und Informationsmanagemen

A stereoselective and flexible synthesis to access both enantiomers of N-acetylgalactosamine and peracetylated N-acetylidosamine

Synthetic approaches towards N-acetylgalactosamine (GalNAc) have been attracting considerable interest since this compound is known for its pivotal role in cell–cell interaction and receptor induced cell signaling. Herein, we present a synthetic route in which two of the four stereogenic centers present in the target compound are derived from enantiopure tartaric acid being selectively converted to epoxy alcohols. The key step is the Pd-catalyzed, stereo- and regioselective epoxide opening and subsequent nucleophilic substitution of an azide functionality. This approach enables the synthesis of the naturally D- and unnaturally L-configured GalNAc, as well as both enantiomers of the largely unknown N-acetylidosamine (IdoNAc)

Wikis im unternehmensinternen Wissensmanagement

Mittels Cross-Case Analyse von acht Fallstudien zum Einsatz von Wikis im un-ternehmensinternen Wissensaustausch wird untersucht, welche Maßnahmen eingesetzt werden, um die aus Literatur und Praxis bekannten Förderfaktoren umzusetzen. Als Ergebnis zeigt sich, dass eine Vorbildfunktion des Manage-ments und klare Ziele den Erfolg wesentlich beeinflussen. Den größten Nutzen ziehen MitarbeiterInnen aus der verbesserten Transparenz, der Durchsuchbar-keit der Wissensbasis, der Dokumentation und dem Austausch von Wissen.Informationstechnologie und Informationsmanagemen