Synthesis and characterization of amine-functionalized microgel particles and their subsequent assembly into colloidal molecule-like clusters by droplet-based microfluidics

The ability of thermoresponsive, amine-functionalized microgel particles to take part in microgelmicrogel inter-cross-linking has previously been reported in the literature, in connection to applications such as for example the formation of stimuli-responsive colloidal gels and colloidosomes [1]. This thesis deals with the synthesis of such thermoresponsive, cross-linkable microgels and their subsequent assembly into clusters using droplet-based microfluidics, with the goal of forming responsive colloidal molecules with well-defined valency. Such colloidal molecules can be used as model systems to study controlled self-assembly processes. In this project, monodisperse amine-functionalized poly(N-isopropylacrylamide) (PNIPAM) and poly(N-isopropylmethacrylamide) (PNIPMAM) microgels, cross-linkable with glutaraldehyde, were synthesized. In total, four microgel systems were produced and the microgels were subsequently characterized by dynamic and static light scattering (DLS and SLS), confocal laser scanning microscopy (CLSM) and electrophoretic mobility. The microgels were shown to exhibit thermoresponsive behavior with respect to size, charge density and interaction potential. In the presence of glutaraldehyde, dense microgel suspensions were converted to macrogels through microgel-microgel cross-linking. Upon heating the macrogels to above the microgels’ volume phase transition temperature (VPTT), they contracted, thus showing that the thermoresponsive behavior of the microgels was conferred to the macrogels. The obtained microgel systems were then used in droplet-based microfluidics to generate colloidal molecule-like clusters. However, the presence of clusters could not be confirmed, likely due to problems with extraction. [1] a) G. Huang, J. Gao, Z. Hu, J. V. St. John, B. C. Ponder and D. Moro. Controlled Drug Release from Hydrogel Nanoparticle Networks. J. Control. Release, 94:303-311, 2004. b) G. Huang and Z. Hu. Phase Behavior and Stabilization of Microgel Arrays. Macromol., 40:3749-3756, 2007. c) R. K. Shah, J.-W. Kim and D. A. Weitz. Monodisperse Stimuli-Responsive Colloidosomes by Self-Assembly of Microgels in Droplets. Langmuir, 26:1561-1565, 2010.Kolloider är partiklar i storleksordningen nm till μm. De är viktiga i biologiska system, där exempelvis proteiner är en typ av kolloid. Att studera kolloider ger oss därför insikt i hur till exempel proteiner byggs upp och interagerar. I detta fall försökte vi tillverka kolloidala molekyler, alltså kolloider som interagerar med varandra genom ett specifikt antal bindningar i väl definierade positioner och riktningar. För att skapa kolloidala molekyler användes mikrogeler som sammansattes till kluster, där antalet bindningar och dess riktning bestäms av antalet mikrogeler och dess position. Mikrogeler är kolloidala partiklar med temperaturberoende egenskaper. Under en viss kritisk temperatur är mikrogelerna stora och vattenälskande och på grund av detta absorberar de vatten. Över den kritiska temperaturen skyr mikrogelerna vatten och krymper ihop. Ändring i temperatur påverkar inte enbart mikrogelernas storlek utan också hur de interagerar med varandra; över den kritiska temperaturen tycker mikrogelerna om att interagera med varandra. Kolloidala molekyler som tillverkas av mikrogeler får mikrogelernas temperaturberoende egenskaper och således kan klustrens egenskaper också styras genom temperaturen. För att kunna skapa kluster av mikrogeler behöver mikrogelerna tillverkas så att möjlighet finns att binda ihop dem med varandra. Mikrogelerna tillverkades därför med amingrupper som fungerar som brofästen. Glutaraldehyd fäster vid amingrupperna och kunde då användas som bro mellan två mikrogeler. För att få mikrogelerna att komma tillräckligt nära varandra, både för att bilda kluster och för att bygga broar mellan dem, så bildade vi vattendroppar innehållande både mikrogeler och glutaraldehyd. Mikrogelerna tvingades närmare varandra i vattendropparna genom att dropparna krymptes. Klustren som bildas antar olika form beroende på hur många mikrogeler som deltar. Fyra olika mikrogeler tillverkades från två olika temperaturkänsliga polymerer, det vill säga långa kedjor av upprepade mindre enheter, och färgades med fluorescerande molekyler. Vi har kunnat visa att mikrogelerna kan bindas ihop genom att låta dem bilda tvärbundna nätverk, geler, från lösningar. Kluster av mikrogeler har inte kunnat isoleras efter droppkrympning, men detta är något som vi hoppas kunna göra i framtiden

Different Approaches of Numerical Analysis of Electromagnetic Phenomena in Shaded Pole Motor with Application of Finite Elements Method

In this paper is used Finite Element Method-FEM for analysis of electromagnetic quantities of small micro motor – single phase shaded pole motor-SPSPM. FEM is widely used numerical method for solving nonlinear partial differential equations with variable coefficients. For that purpose motor model is developed with exact geometry and material’s characteristics. Two different approaches are applied in FEM analysis of electromagnetic phenomena inside the motor: magneto-static where all electromagnetic quantities are analysed in exact moment of time meaning frequency f=0 Hz and timeharmonic magnetic approach where the magnetic field inside the machine is time varying, meaning frequency f=50 Hz. Obtained results are presented and compared with available analytical result

Kön, Diagnos och Mognad - en kvalitativ innehållsanalys av information om transsexualism på hemsidor

This study aims to examine how the concepts of gender, diagnose, maturation and transsexualism are described and socially constructed on websites. To understand how the concepts we prepared to interpret nine sites using Berger and Luckmann's social constructivist perspective, and by Foucault´s theory about power. The theories focus on that we are living within a society which perpetuates normative gender roles. The different owners of the websites presented concepts differ depending on the purpose they had with their information. Summary we saw during our work how complex all the concepts were and how difficult it was to find a unified description of the concepts. Although we live in a society well developed we did find during our work how the gender roles is still solid and it seems like we live in a society hard to understand and accept the grey area between the constructed gender roles man and woman. Our results shows that through the power of language and how we use it we keep the gender roles alive and maintains the society´s way of looking at gender as a specific role

Organizational exposure to risk of unethical behaviour

Issues: The issues Swedwood asked us to explore in their Eastern European timber purchasing organizations were: Have clear directives been given to each purchasing unit regarding the purpose and scope of its activities? If so, what do these directives contain? If so, how are these directives followed? How are purchasing transactions planned and carried out? What roles are involved in the purchasing process, and what are the responsibilities and authorities of each role? Can the purchasing process, or parts of the process, be improved? Can the company organize its purchasing units more effectively to ensure best practices? Purpose: The overall approach we took was to assess Swedwood's potential exposure to low levels of legal or ethical practices by benchmarking its actual practices, using the concept of best purchasing practices described in the literature. Method: To collected data using qualitative methods, since this is an appropriate way of raising the sensitive issues that needed to be addressed. This involved interviewing local purchasing organisations about their local market conditions, organisational structure and purchasing processes. Conclusion: The study has shown that organisations' purchasing managers are exposed to considerable risks of low levels of ethical practices. While most local organisations have policies to prevent corruption, there is rarely a working manual to provide people with guidelines to achieve this. Support for ethical practices could probably be improved.Swedwood är ett dotterbolag till IKEA som grundades 1991. Deras huvuduppgift är att säkra produktionskapacitet på trämöbler där IKEA haft svårigheter att anskaffa rätt produkter till rätt pris. Deras anläggningar består av sågverk, träkomponent- ochm öbelfabriker. Många av de länder Swedwood investerar i är i Transparency Internationals Corruption index lågt rankade, och företaget är därför oroat över dess utsatthet i inköpsarbetet. Riskerna är alltid större då stora summor är inblandade, och timmerinköp är ett sådant område. Syftet med denna studie var att kartlägga företagets organisation och arbetsrutinerna vid timmerinköp i 6 Östeuropeiska länder. Målet är att därigenom fastställa den potentiella utsattheten och vad man kan förbättra. Vår litteraturstudie innefattar såväl konventionell inköpsteori som organisationsteori och inköpsetik. Genom att använda teorin som referensram belyste vi i analysen den potentiella organisatoriska risken vid varje enhet. Vi har använt oss av en kvalitativ forskningsansats vid insamlandet av data. I diskussionen berörs de huvudsakliga problemen som är: vikten av en tydlig policy, problematiken med organisationsutformningen, samt insyn och transparens. Genom att belysa empirin med litteraturen, föreslår vi rekommendationer för organisationsstruktur och arbetsutförande vilket syftar till att reducera riskerna och företagets utsatthet. Förslagen innefattar skapandet av en inköpsmanual, regelbunden träning inom etik och idéer för att höja den organisatoriska förmågan att lära i etiska och säkerhetsmässiga frågor. Vår slutsats är att policys för inköp, mätning, samt arbetsinstruktioner för dessa områden kan förstärkas. Riktlinjer är viktiga som målsättning och som referens i organisationer. Lika viktigt är att budskapet når ut. Vi fann att det fanns risker i inköpsorganisationen. Vi drar också slutsatsen att lösningen och problematiken är en kombination av metodik, teknik och kultur

Den officiella, formella & informella organisationsbilden - Malmö Förskoleförvaltning

Title: The Official, Formal & Informal organizational image – The Pre-School Administration in Malmo City Date: 2015-02-18 Course: FEKH49, Degree Project Undergraduate level, Business Administration, Undergraduate level, 15 University Credits Points (UPC) or ECTS‐cr) Authors: Surra Al Sakban, Emil Gustafsson, Karin Runnerström Advisor: Louise Bringselius Key words: Public sector, Professional Bureaucracy, Organizational structure, Formal structure, Informal structure, Pre-School Administration in Malmo City. Purpose: To gain understanding how different images of an organisation’s structure may arise and recognize the significance and function of the different images. Methodology: A qualitative case study. Primary data was retrieved through seven semistructured interviews and minor complementary observations. Theoretical perspectives: The Professional Bureaucracy, Formal and Informal Organization. Empirical foundation: Collection of empirical data through conducting seven semi-structured interviews with personnel from the Pre-School Administration in Malmo City along with minor complementary observations. Conclusions: This study illustrates that an organization may display multiple images of the organizational structure. As current research describes the formal and informal organization, this report presents an additional dimension; the official image. Since it is not always evident what belongs to the formal or informal organization, a more in depth breakdown may be necessary. This research depicts three different images, "The Official Image", "The Formal Image" and "The Informal Image" of a public organization. The Official Image is what the organization portrays in order to accommodate public demand. The Formal Image, accounts for the written rules and regulations that organizations must adhere too and The Informal Image is the actual organizational structure. All three images fulfill a purpose and are closely connected, this report will attempt to define them more closely

Impact of Interatrial Shunts on Invasive Hemodynamics and Exercise Tolerance in Patients With Heart Failure

Approximately 50% of patients with heart failure have preserved ejection fraction. Although a wide variety of conditions cause or contribute to heart failure with preserved ejection fraction, elevated left ventricular filling pressures, particularly during exercise, are common to all causes. Acute elevation in left-sided filling pressures promotes lung congestion and symptoms of dyspnea, while chronic elevations often lead to pulmonary vascular remodeling, right heart failure, and increased risk of mortality. Pharmacologic therapies, including neurohormonal modulation and drugs that modify the nitric oxide/cyclic GMP-protein kinase G pathway have thus far been limited in reducing symptoms or improving outcomes in patients with heart failure with preserved ejection fraction. Hence, alternative means of reducing the detrimental rise in left-sided heart pressures are being explored. One proposed method of achieving this is to create an interatrial shunt, thus unloading the left heart at rest and during exercise. Currently available studies have shown 3- to 5-mm Hg decreases of pulmonary capillary wedge pressure during exercise despite increased workload. The mechanisms underlying the hemodynamic changes are just starting to be understood. In this review we summarize results of recent studies aimed at elucidating the potential mechanisms of improved hemodynamics during exercise tolerance following interatrial shunt implantation and the current interatrial shunt devices under investigation