Formation of Block Copolymer and Surfactant Vesicles

In this thesis temperature induced vesicle formation in both a block copolymer system and nonionic surfactant system have been investigated. The block copolymer is a triblock copolymer of poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO), PEO-PPO-PEO, with the average molecular composition of EO5PO68EO5 and the commercial trade name Pluronic L121 (papers I, II). In the L121 system the formation of amphiphilic particles with internal structure has also been observed (paper III). The nonionic surfactant studied is tetraethyleneglycol dodecyl ether (C12E4) (paper IV). In addition, a study of the miscibility of L121 and soybean phosphatidylcholine also denoted Lecithin, with the commercial trade name Epikuron 200, was performed (paper V). To characterize the systems, static and dynamic light scattering (SLS and DLS), nuclear magnetic resonance (NMR), cryogenic transmission electron microscopy (cryo-TEM) and small angle X-ray scattering (SAXS) have been used. The most important conclusions are: i) The Pluronic L121 and lecithin do not form mixed aggregates (paper V). ii) L121 can form vesicles in water (paper I, II). iii) In the L121 system one can study vesicle self-assembly from a solution of monomers (unimers) (paper II). iv) In the L121 system the block copolymer polydispersity affects the vesicle self-assembly and its temperature dependence (paper II). v) In the C12E4 system, vesicles can form upon heating a micellar solution (paper IV). vi) The vesicle size distribution depends on the heating rate, and can be roughly understood from the diffusion limited aggregation/fusion of micelles (paper IV). vii) In the L121 system nanosized particles with an internal structure can be formed (paper III)

Optimization of Monte Carlo simulations

This thesis considers several different techniques for optimizing Monte Carlo simulations. The Monte Carlo system used is Penelope but most of the techniques are applicable to other systems. The two mayor techniques are the usage of the graphics card to do geometry calculations, and raytracing. Using graphics card provides a very efficient way to do fast ray and triangle intersections. Raytracing provides an approximation of Monte Carlo simulation but is much faster to perform. A program was also written in order to have a platform for Monte Carlo simulations where the different techniques were implemented and tested. The program also provides an overview of the simulation setup, were the user can easily verify that everything has been setup correctly. The thesis also covers an attempt to rewrite Penelope from FORTAN to C. The new version is significantly faster and can be used on more systems. A distribution package was also added to the new Penelope version. Since Monte Carlo simulations are easily distributed, running this type of simulations on ten computers yields ten times the speedup. Combining the different techniques in the platform provides an easy to use and at the same time efficient way of performing Monte Carlo simulations

Optimization of Monte Carlo simulations

This thesis considers several different techniques for optimizing Monte Carlo simulations. The Monte Carlo system used is Penelope but most of the techniques are applicable to other systems. The two mayor techniques are the usage of the graphics card to do geometry calculations, and raytracing. Using graphics card provides a very efficient way to do fast ray and triangle intersections. Raytracing provides an approximation of Monte Carlo simulation but is much faster to perform. A program was also written in order to have a platform for Monte Carlo simulations where the different techniques were implemented and tested. The program also provides an overview of the simulation setup, were the user can easily verify that everything has been setup correctly. The thesis also covers an attempt to rewrite Penelope from FORTAN to C. The new version is significantly faster and can be used on more systems. A distribution package was also added to the new Penelope version. Since Monte Carlo simulations are easily distributed, running this type of simulations on ten computers yields ten times the speedup. Combining the different techniques in the platform provides an easy to use and at the same time efficient way of performing Monte Carlo simulations

Preventive health work against depression: The experiences from young adult patientes : A Literature review

Bakgrund: Depression räknas som ett psykiatriskt sjukdomstillstånd, symtom kan lindras och behandlas. Depression bedöms vara den tredje största orsaken till sjukdomsbörda i världen. Globalt sett beräknas runt 280 miljoner människor att lida av depression, Inom Sverige diagnosticeras cirka 19% av befolkning mellan 16-84 år någon gång i livet med depression. Primärvård den första kontakten inom hälso- och sjukvårdsystemet för många unga vuxna som söker med psykisk ohälsa. Till följd ställs då högre krav på den grundutbildade sjuksköterskan att möta patienter med adekvata preventiv omvårdnad mot depression. Syfte: Syftet med litteraturstudien var att belysa unga vuxna patienters upplevelse av omvårdnad vid preventivt hälsoarbete mot depression inom primärvården. Metod: Litteraturstudie kvalitativ ansats baserades på tolv vetenskapliga studier. Databassökningar gjordes i Cinahl och PubMed. Resultat: Resultatet identifierad två huvudkategorier: Bemötande i omvårdnad, Underlättande faktorer och barriärer inom omvårdnad. Huvudkategorierna omfattade fem underkategorier: Vårdrelation, Patientens delaktighet, Hälsoundervisning, Unga vuxnas omgivning, Vårdens tillgänglighet. Konklusion: Unga vuxna patienter som söker vård vid depression beskriver att en anpassad personcentrerad vård är en grund för en god omvårdnad. Empatiskt bemötande, delaktighet i den egna vården, lätt tillgänglighet och bra information bidrar till att patientens egna resurser stärks till att vidta hälsofrämjande åtgärder i preventivt syfte mot depression. Bakgrund: Depression is considered a psychiatric illness, symptoms can be alleviated and treated. Depression is estimated to be the third largest cause of disease burden in the world. Globally around 280 million people are estimated to suffer from depression. Within Sweden approximately 19% of the population between 16-84 years is diagnosed with depression at some point in their lives. Primary care is the first point of contact within the health care system for many young adults who apply with mental health problems. As a result, higher demands are placed on the basic nurse to meet patients with adequate preventive nursing care against depression. Aim: The purpose of the literature study was to shed light on young adult patients' experience of nursing measures in preventive health work against depression in primary care. Method: Literature study qualitative approach was based on twelve scientific research. Database searches were performed in Cinahl and PubMed. Result: The result identified two main categories: Treatment in nursing care, Facilitating factors and barriers within nursing. The main categories consisted of five subcategories: Care relationship, Patient participation, Health education, Young adult’s environment, Availability of care. Conclusion: Young adult patients who seek care for depression describes that an adapted person-centered care is a base for good nursing care. Empathic treatment, participation in patients own care, easy accessibility and good information contribute to the strengthening of the patient's own resources to take health-promoting measures in preventive purposes against depression

”When I go on TOR, I am a completely different person” : A qualitative interview study about the motives behind the usage of Tor Browser and The Dark Web

Denna studie har som mål att ge en inblick i varför och hur Internetanvändare nyttjar Tor Browser och The Dark Web. Nätverket och webbläsaren förknippas ofta med illegal verksamhet, men även med yttrandefrihet och anonymitet. Vi vill undersöka hur användandet av dessa ser ut och skapa en förståelse kring varför individer väljer att vända sig dit. Detta görs med hjälp av kvalitativa intervjuer med sammanlagt nio personer som använder sig av nätverket och webbläsaren. Intervjuerna har genomförts på forumen Flashback Forum, Quora och Reddit genom sajternas privata chattfunktioner. Materialet har sedan analyserats med hjälp av det teoretiska perspektivet Uses and Gratification för att synliggöra vilka sociala och psykologiska behov som tillgodoses genom användandet. Studiens resultat visade att merparten av de intervjuade vände sig till Tor Browser och The Dark Web eftersom att de, i förstahand, var intresserade av illegal verksamhet och använde nätverket samt webbläsaren för att få tillgång till materialet, men även för att göra det svårare för myndigheter att spåra deras aktivitet online. Användandet grundade sig, i andrahand, i ett intresse för yttrandefrihet och anonymitet och det var även dessa ämnen som gjorde att användarna fortsatte att återvända till Tor Browser och The Dark Web.

Preventive health work against depression: The experiences from young adult patientes : A Literature review

Bakgrund: Depression räknas som ett psykiatriskt sjukdomstillstånd, symtom kan lindras och behandlas. Depression bedöms vara den tredje största orsaken till sjukdomsbörda i världen. Globalt sett beräknas runt 280 miljoner människor att lida av depression, Inom Sverige diagnosticeras cirka 19% av befolkning mellan 16-84 år någon gång i livet med depression. Primärvård den första kontakten inom hälso- och sjukvårdsystemet för många unga vuxna som söker med psykisk ohälsa. Till följd ställs då högre krav på den grundutbildade sjuksköterskan att möta patienter med adekvata preventiv omvårdnad mot depression. Syfte: Syftet med litteraturstudien var att belysa unga vuxna patienters upplevelse av omvårdnad vid preventivt hälsoarbete mot depression inom primärvården. Metod: Litteraturstudie kvalitativ ansats baserades på tolv vetenskapliga studier. Databassökningar gjordes i Cinahl och PubMed. Resultat: Resultatet identifierad två huvudkategorier: Bemötande i omvårdnad, Underlättande faktorer och barriärer inom omvårdnad. Huvudkategorierna omfattade fem underkategorier: Vårdrelation, Patientens delaktighet, Hälsoundervisning, Unga vuxnas omgivning, Vårdens tillgänglighet. Konklusion: Unga vuxna patienter som söker vård vid depression beskriver att en anpassad personcentrerad vård är en grund för en god omvårdnad. Empatiskt bemötande, delaktighet i den egna vården, lätt tillgänglighet och bra information bidrar till att patientens egna resurser stärks till att vidta hälsofrämjande åtgärder i preventivt syfte mot depression. Bakgrund: Depression is considered a psychiatric illness, symptoms can be alleviated and treated. Depression is estimated to be the third largest cause of disease burden in the world. Globally around 280 million people are estimated to suffer from depression. Within Sweden approximately 19% of the population between 16-84 years is diagnosed with depression at some point in their lives. Primary care is the first point of contact within the health care system for many young adults who apply with mental health problems. As a result, higher demands are placed on the basic nurse to meet patients with adequate preventive nursing care against depression. Aim: The purpose of the literature study was to shed light on young adult patients' experience of nursing measures in preventive health work against depression in primary care. Method: Literature study qualitative approach was based on twelve scientific research. Database searches were performed in Cinahl and PubMed. Result: The result identified two main categories: Treatment in nursing care, Facilitating factors and barriers within nursing. The main categories consisted of five subcategories: Care relationship, Patient participation, Health education, Young adult’s environment, Availability of care. Conclusion: Young adult patients who seek care for depression describes that an adapted person-centered care is a base for good nursing care. Empathic treatment, participation in patients own care, easy accessibility and good information contribute to the strengthening of the patient's own resources to take health-promoting measures in preventive purposes against depression

Vesicle formation from temperature jumps in a nonionic surfactant system

When heating a dilute sample of the binary system of tetraethyleneglycol dodecyl ether (C12E4) and water from the micellar phase (L-1) into the two-phase region of a lamellar phase (L-alpha) and excess water (W) vesicles are formed. During heating, one passes a region of phase separation in the micellar phase (L-1' + L-1") where the initial micelles rapidly fuse into larger aggregates forming the concentrated L-1 phase (L-1") with a structure of branched cylindrical micelles, a so-called "living network". The static correlation length of the micelles are increasing with increasing concentration, from ca. 10 nm to 80 nm in the concentration range of 0.0001 g/cm(3)-0.0035 g/cm(3). The overlap concentration was determined to 0.0035 g/cm(3). When the temperature reaches the L-1' + L-alpha region the network particles transform into bilayer vesicles with a z-average apparent hydrodynamic radius in the order of 200 nm depending on the composition. The size of the final vesicles depends on the extent of aggregation/fusion in the L-1' + L-1" region and hence on the rate of heating. The aggregation/fusion in the L-1' + L-1" is slower than diffusion-limited aggregation, and it is shown that 1/100 of the collisions are sticky results in the fusion event