Background Research has shown varying and uncertain effects of oral nutritional supplements (ONS) and descriptions on the use of ONS in studies have been incomplete. To get valid study results on the effects of ONS, it is important that study participants adhere to ONS interventions. However, it is unclear how adherence have affected study results on ONS in earlier studies.  Aim To map characteristics of quantitative studies from the 21st century investigating adherence to ONS in patients with malnutrition. Method The general structure of systematic reviews was chosen. In the literature search, articles that investigated patients with malnutrition or risk for malnutrition as target population, ONS as intervention and adherence to ONS as outcome, were inspected. A PICO-question was formulated for the literature search. For the data extraction, a variable key document with variables and codes, that were to be extracted from the included articles, were explicitly created for this thesis. A pilot study with thirteen (10%) articles was conducted to test and adjust the variable key document. The result was presented using descriptive statistics. Results Out of the 134 included articles, the majority were RCTs (60.0%) from industrialized countries. Most of the articles investigated solely the effect of some kind of ONS intervention (51.4%), more precisely a milk-based industrial ONS (56.0%). Many of the variables of interest, were not reported in the articles. Other terms than ‘oral nutritional supplements’ (60.4%) were used more frequently than ‘oral nutritional supplements’ (39.6%). The term ‘compliance’ was used in 68.7% of the articles and ‘adherence’ in 27.0%. Adherence was most often studied as a secondary outcome (47.8%) and measured in different ways but most frequently with diaries or daily records of ONS intake (21.6%). Conclusion Future studies investigating ONS should aim for completeness and accuracy in descriptions of the study method regarding ONS and adherence to ONS to better facilitate comparison between studies. The present review could be used to guide researchers during the process when planning studies on ONS and adherence to ONS. / Bakgrund Studier som undersökt effekten av näringsdrycker har visat på varierande och osäkra resultat och beskrivningen av hur näringsdryck används har varit bristfällig. För att få studieresultat med hög validitet om effekten av näringsdrycker är det viktigt att studiedeltagare är följsamma till ordinationen av näringsdryck. Det är oklart hur följsamheten till ordination av näringsdryck har påverkat studieresultaten hittills.  Syfte Att kartlägga studiedetaljer i kvantitativa studier från 2000-talet som undersökt följsamhet till ordinationer av näringsdrycker bland patienter med malnutrition.  Metod Den generella strukturen för systematisk litteraturöversikt valdes. I litteratursökningen granskades artiklar som undersökte patienter med malnutrition eller risk för malnutrition som målgrupp, näringsdrycker som intervention och följsamhet till ordination av näringsdryck som utfall. För dataextraheringen formulerades en variabelnyckel, specifikt för denna litteraturöversikt, med variabler och koder som skulle extraheras ur inkluderade artiklar. En pilotstudie med tretton (10%) artiklar gjordes för att testa och anpassa variabelnyckeln. Resultatet presenterades med deskriptiv statistik. Resultat Av de 134 inkluderade studierna var majoriteten RCT-studier (60,0%) från industrialiserade länder. Största delen av studierna undersökte enbart effekten av näringsdrycker (51,4%), närmare bestämt mjölkbaserade industriframställda näringsdrycker (56,0%). Många av de variabler som var av intresse att studera rapporterades inte i artiklarna. Andra termer än ‘oral nutritional supplements’ (60,4%) användes mer frekvent än ‘oral nutritional supplements’ (39,6%). Termen ‘compliance’ användes i 68,7% av studierna och ‘adherence’ användes i 27,0%. Följsamheten till näringsdrycker undersöktes oftast som ett sekundärt utfall (47,8%) och det undersöktes på olika sätt men oftast med dagbok eller daglig registrering av intaget av näringsdryck (21,6%). Slutsats Framtida studier som undersöker näringsdrycker bör försöka uppnå fullständig och noggrann rapportering av studiemetoden relaterad till användandet av näringsdryck och följsamhet till ordination av näringsdryck för att bättre kunna jämföra resultat mellan studier. Denna litteraturöversikt skulle kunna användas för att vägleda forskare under processen när de planerar studier på näringsdrycker och följsamhet till ordination av näringsdrycker.

Made available in DSpace on 2015-04-14T13:58:26Z (GMT). No. of bitstreams: 1 401355.pdf: 1369287 bytes, checksum: 2023585a5f248c0e60eaa5836d62deb3 (MD5) Previous issue date: 2008-03-28 / No presente trabalho, estudou-se a cria??o de defeitos em cristais i?nicos de fluoreto de l?tio (LiF) irradiados com ?ons de ouro (Au) com energias da ordem de 3 a 15 MeV. O objetivo principal foi avaliar a efeito da taxa de dose (ou corrente i?nica) na produ??o de centros de cores nas amostras irradiadas. Amostras de LiF monocristalino clivado no plano [100] foram irradiadas com flu?ncias entre 5x10?? a 2x10 [na d?cima quarta pot?ncia] ?ons/cm? e correntes entre 1 e 210 nA/cm?. Algumas amostras foram expostas a diferentes temperaturas, observando sua influ?ncia na gera??o de defeitos. A partir da cria??o de vac?ncias ou deslocamentos de ?ons da rede para o interst?cio, centros de cores s?o gerados, produzindo mudan?as nas caracter?sticas ?pticas e el?tricas do cristal. Os centros de cores gerados nos cristais de LiF foram analisados atrav?s de espectroscopia ?ptica na faixa entre 190 a 1200 nm (UV IR-VIS). Para baixas flu?ncias, ocorre a predomin?ncia do centro - F nos espectros medidos. Com o aumento da flu?ncia foi observado que, centros - Fn e agregados dominam a espectro de absorb?ncias. Para ?ons de 10 MeV, o raio efetivo de forma??o dos centros - F em torno da trilha do ?on foi estimado em torno de 2,2 nm para o centro F. Para o centros F2 e F3 o raio efetivo ficou em torno de 1,2 nm e 0,2 nm respectivamente. Para uma flu?ncia e corrente fixa, canstata-se que numero de defeitos gerados aumenta proporcionalmente com a energia dos ?ons incidentes devido ao aumento do dE/dx m?dio e da energia m?dia dos el?trons secund?rios gerados. Por fim, foi observado para baixas flu?ncias que os danos gerados s?o praticamente independentes do valor da taxa de dose. Contudo, a taxa de dose ? significativa quando a flu?ncia aplicada no material for alta, da ordem de 5x10?? ?ons/cm? ou maior. Observou-se que a concentra??o dos centros de cores ? proporcional a (i) [1/3 na pot?ncia]. O efeito da taxa de dose esta relacionado ? altera??o da din?mica da forma??o dos defeitos, quando dois ou mais impactos i?nicos se sobrep?em espacialmente e temporalmente. 0 aquecimento transiente da amostra, devido ?s altas correntes, tamb?m influencia na maior efici?ncia na produ??o dos centros de cores, mas n?o da conta completa do efeito da corrente que ? observado mesmo as amostras s?o resfriadas durante a irradia?ao.

Made available in DSpace on 2015-04-14T13:59:07Z (GMT). No. of bitstreams: 1 458715.pdf: 5795681 bytes, checksum: 3ee2d099095b821e73a487ab66a67e36 (MD5) Previous issue date: 2014-03-20 / The use of electrostatic or magnetic lenses is an efficient but expensive way to obtain microbeams of high energy ions. The mechanical confinement of ion beams through linear structures is an alternative way to produce microbeams. In this work, we have used tapered glass micro-capillaries with exit openings between 2 m and 118 m produced by controlled heating and stretching. Microbeams of heavy ions in the MeV energy range were produced at the 3 MV HVEE Tandetron accelerator at the Federal University of Rio Grande do Sul. The transmission and beam energy straggling of different microcapillaries inserted into a goniometer were measured using 1-1,5 MeV H+ beams. The best alignment condition was obtained inspecting the goniometer position which maximized the beam count at the initial energy and minimize broadening of the detected beam energy. For some capillaries there was only one position corresponding to a maximum transmission of the beam. In other cases, the alignment is lost gradually. The energy spectra in the maximum transmission condition had FWHM between 18 and 158 keV and the angular dispersion ranged between 0.2? and 1.6?. The best beam collimation was obtained with capillary tips with intermediate diameters between 3 μm e 17 μm. In order to evaluate the final beam, polycarbonate (PC) foils were exposed to different fluences (between 1014 e 1016 ions/cm2) of the produced microbeam (1 MeV H+ and 18 MeV Au7+). Markings were done on PC samples. In some cases the marks were not circular and appeared to be partially blocked. The increase of incident ions fluence in the sample results in the growth of the diameter of the produced markings. Profiles of the markings produced were evaluated. The FWHM was between 38 e 90 μm and the beam spread was between 0.15? and 0.20?. Experiments using a CCD camera to detect the microbeam were also performed. / O emprego de um conjunto de lentes eletrost?ticas ou magn?ticas ? uma maneira eficiente de se obter microfeixes i?nicos altamente energ?ticos, mas sua constru??o ? bastante dispendiosa. O confinamento mec?nico de feixes de ?ons atrav?s de estruturas lineares se apresenta como segunda via em rela??o a essa t?cnica tradicional. Foram fabricados microcapilares c?nicos de vidro com pontas entre 2 m e 118 m atrav?s de aquecimento e estiramento controlado. Experimentos de produ??o dos microfeixes com os microcapilares foram realizados no acelerador de ?ons 3 MV, do Laborat?rio de Implanta??o I?nica do IF-UFRGS. Utilizou-se feixes de H+ com energia entre 1 e 1,5 MeV e um goni?metro para testes de alinhamento e transmiss?o do feixe atrav?s dos microcapilares. Para cada capilar foi obtida uma posi??o bem definida de alinhamento. Em alguns casos observaram-se quedas bruscas do sinal ao variar o ?ngulo em 0,1? e em outros o alinhamento ? perdido de forma gradativa. Os espectros de energia apresentaram FWHM entre 18 e 158 keV na condi??o de transmiss?o m?xima. A dispers?o angular variou entre 0,2? e 1,6?. A melhor colima??o do feixe foi obtida com capilares de pontas com di?metros intermedi?rias, entre 3 μm e 17 μm. Amostras de policarbonato foram irradiadas com microfeixes de H+ de 1 MeV e Au7+ de 18 MeV, produzidos atrav?s dos capilares de vidro. A flu?ncia variou entre 1014 e 1016 ?ons/cm2. Diferentes padr?es na forma das marcas feitas nos pol?meros foram revelados: foram encontradas marcas circulares, marca??es em forma de c e em formato alongado. O aumento da flu?ncia de ?ons incidentes na amostra resulta no acr?scimo do di?metro da marca??o produzida. Os perfis das marca??es apresentaram FWHM ficou entre 38 e 90 μm e o grau de diverg?ncia do feixe est? entre 0,15? e 0,20?. Estudos preliminares de visualiza??o do microfeixe com uma c?mera CCD tamb?m foram implementados.

Submitted by Setor de Tratamento da Informa??o - BC/PUCRS (tede2@pucrs.br) on 2015-04-17T13:52:43Z No. of bitstreams: 1 467312 - Texto Completo.pdf: 12104060 bytes, checksum: fab068a173a82aab41a55d8875dc36ae (MD5) / Made available in DSpace on 2015-04-17T13:52:43Z (GMT). No. of bitstreams: 1 467312 - Texto Completo.pdf: 12104060 bytes, checksum: fab068a173a82aab41a55d8875dc36ae (MD5) Previous issue date: 2015-03-30 / In this study the spatial confinement effects on the topological (mass transport and particle ejection) and chemical modifications of poly(methyl methacrylate) thin films (1<?<360 nm) irradiated by swift heavy ions were systematically investigate. The surface tracks dimensions were characterized by atomic force microscopy and the results show that the surface effects are weakened when the length of the ion track is spatially confined down to few nanometers. The deviation from bulk-like behavior starts at a critical thickness ?1 as large as ~40 nm to the ridge volume, due to effects associated to cooperative action of excited material along the track. However, ?1 is much smaller for effects related to events close to the surface, such as the crater size (?1~10 nm). Analytical calculations based on the pressure pulse model were carried out to investigate theoretical aspects of the ion-matter energy transfer in the transport and dissipation of the deposited energy. The results obtained from these calculations match the experimental observations. Chemical modifications were investigated by quantifying bond breaking rates, extracted by x-ray photoelectron spectroscopy. Cross sections for carbon-oxygen bonds for films under Bi irradiation are slightly smaller for thinner films, whilst for proton irradiation the values do not show substantial difference down to the smallest thickness viable for analysis (?~5 nm). From these set of data it is verified that the ionic irradiation effects on polymer thin films are weakened under spatial confinement into layers with ? below a certain critical value ?1, dependent on the probed effect. Substantial difference on the surface track dimensions were not observed between the distinct substrates investigated. / Neste trabalho foram investigados sistematicamente os efeitos de confinamento espacial nas modifica??es topol?gicas (transporte de massa e eje??o de part?culas) e qu?micas induzidas por ?ons pesados de alta energia (de dezenas a milhares de MeV) em filmes finos de poli(metacrilato de metila) (1< ? <360 nm). As dimens?es dos efeitos de superf?cie induzidos pela irradia??o foram caracterizadas por microscopia de for?a at?mica e os resultados mostram claramente o enfraquecimento dos efeitos induzidos pela irradia??o quando o comprimento da trilha ? reduzido a poucos nan?metros. Desvios do comportamento observado para filmes bulk come?am em uma espessura cr?tica ?1 t?o grande quanto ~40 nm para o volume da protuber?ncia, devido ? redu??o dos efeitos de a??o cooperativa de material excitado ao longo da trilha. Entretanto, ?1 ? bem menor para efeitos relacionados a eventos pr?ximos ? superf?cie, como o tamanho cratera (?1~10 nm). C?lculos anal?ticos pelo modelo do pulso de press?o foram utilizados para investigar aspectos te?ricos da transfer?ncia de energia ?on-material no transporte e dissipa??o da energia depositada. Os resultados obtidos a partir desses c?lculos corroboram com observa??es experimentais. As modifica??es qu?micas foram investigadas atrav?s das se??es de choque de quebra de liga??es, extra?das por espectroscopia de fotoel?trons por raios x. As se??es de choque de danos para as liga??es carbonooxig?nio, obtidas para irradia??es com ?ons de Bi de 2,2 GeV, s?o levemente reduzidas para filmes mais finos, enquanto as se??es de choque para filmes irradiados com pr?tons de 2 MeV n?o mostram diferen?as significativas at? a espessura mais fina acess?vel por an?lise de XPS (?~5 nm). A partir desse conjunto de dados verificou-se o enfraquecimento dos efeitos induzidos pela irradia??o em filmes polim?ricos sob confinamento espacial em camadas com ? abaixo de um valor cr?tico ?1, sendo ?1 dependente do efeito sondado. N?o foram observadas diferen?as significativas do efeito da espessura para diferentes substratos.

The unfolded protein response (UPR) is induced by a variety of external and internal stimuli, including accumulation of misfolded proteins in the endoplasmic reticulum (ER). Viruses such as Herpes Simplex Virus type 1 (HSV-1) induce host cells to produce viral proteins many of which undergo glycosylation and other modifications in the ER, causing stress to the ER and consequently UPR activation. I have tested the hypothesis that HSV-1 has evolved strategies to regulate the UPR in order to suppress aspects of the UPR that might interfere with viral replication and to promote pathways that aid its own survival and replication. The purpose of this study was to test the hypothesis that HSV-1 selectively modulates the three pathways (PERK, ATF6, and IRE-1) of the UPR in epithelial and neuronal cells and to examine the similarities and the differences between these two types of cells in their responses to ER stress. Vero and ONS-76 cells were used as models of epithelial and neuronal cells respectively and qRT PCR technique was used for analyzing RNA levels of transcripts of spliced Xbp1, HERP, CHOP and BIP, selected target genes for three pathways of the UPR. HSV-1 DNA synthesis and infectious virus production in infected cells showed that compared to the permissive Vero cells, ONS-76 cells seemed to be semi-permissive to HSV-1 infection with limited viral DNA synthesis and infectious virus production. The kinetics of transcript and protein synthesis for genes representing immediate early, early and late classes of viral genes was also monitored. Expression of the immediate early gene, ICP0, was similar in both cell types but the expression of the early gene, TK and late genes VP16 and VP 5 was different. My work reveals that HSV-1 infection in cells of epithelial and neuronal origins results in activation of the UPR, but through cell type selective regulation of the three signal transduction pathways of the UPR (PERK, ATF6, and IRE-1). While HSV-1 infection resulted in upregulation of Spliced Xbp1 and its target gene HERP (IRE1 pathway) and downregulation of BIP (ATF6 pathway) in both cell types, CHOP (PERK pathway) was upregulated only in ONS cells. My results suggest that some aspects of the UPR are regulated differently in cells representing the sites for HSV-1 lytic and latent infections. This may indicate the need for increasing the capacity for protein folding and degradation (Xbp1 and ATF6-induced) in both cells but a requirement for suppressing apoptosis (PERK-induced) only in epithelial cells. As well, I show that HSV-1 infection not only selectively activates the UPR pathways in different cell types, but also inactivates some components of the UPR pathways activated by the drug thapsigargin.

The unfolded protein response (UPR) is induced by a variety of external and internal stimuli, including accumulation of misfolded proteins in the endoplasmic reticulum (ER). Viruses such as Herpes Simplex Virus type 1 (HSV-1) induce host cells to produce viral proteins many of which undergo glycosylation and other modifications in the ER, causing stress to the ER and consequently UPR activation. I have tested the hypothesis that HSV-1 has evolved strategies to regulate the UPR in order to suppress aspects of the UPR that might interfere with viral replication and to promote pathways that aid its own survival and replication. The purpose of this study was to test the hypothesis that HSV-1 selectively modulates the three pathways (PERK, ATF6, and IRE-1) of the UPR in epithelial and neuronal cells and to examine the similarities and the differences between these two types of cells in their responses to ER stress. Vero and ONS-76 cells were used as models of epithelial and neuronal cells respectively and qRT PCR technique was used for analyzing RNA levels of transcripts of spliced Xbp1, HERP, CHOP and BIP, selected target genes for three pathways of the UPR. HSV-1 DNA synthesis and infectious virus production in infected cells showed that compared to the permissive Vero cells, ONS-76 cells seemed to be semi-permissive to HSV-1 infection with limited viral DNA synthesis and infectious virus production. The kinetics of transcript and protein synthesis for genes representing immediate early, early and late classes of viral genes was also monitored. Expression of the immediate early gene, ICP0, was similar in both cell types but the expression of the early gene, TK and late genes VP16 and VP 5 was different. My work reveals that HSV-1 infection in cells of epithelial and neuronal origins results in activation of the UPR, but through cell type selective regulation of the three signal transduction pathways of the UPR (PERK, ATF6, and IRE-1). While HSV-1 infection resulted in upregulation of Spliced Xbp1 and its target gene HERP (IRE1 pathway) and downregulation of BIP (ATF6 pathway) in both cell types, CHOP (PERK pathway) was upregulated only in ONS cells. My results suggest that some aspects of the UPR are regulated differently in cells representing the sites for HSV-1 lytic and latent infections. This may indicate the need for increasing the capacity for protein folding and degradation (Xbp1 and ATF6-induced) in both cells but a requirement for suppressing apoptosis (PERK-induced) only in epithelial cells. As well, I show that HSV-1 infection not only selectively activates the UPR pathways in different cell types, but also inactivates some components of the UPR pathways activated by the drug thapsigargin.

The unfolded protein response (UPR) is induced by a variety of external and internal stimuli, including accumulation of misfolded proteins in the endoplasmic reticulum (ER). Viruses such as Herpes Simplex Virus type 1 (HSV-1) induce host cells to produce viral proteins many of which undergo glycosylation and other modifications in the ER, causing stress to the ER and consequently UPR activation. I have tested the hypothesis that HSV-1 has evolved strategies to regulate the UPR in order to suppress aspects of the UPR that might interfere with viral replication and to promote pathways that aid its own survival and replication. The purpose of this study was to test the hypothesis that HSV-1 selectively modulates the three pathways (PERK, ATF6, and IRE-1) of the UPR in epithelial and neuronal cells and to examine the similarities and the differences between these two types of cells in their responses to ER stress. Vero and ONS-76 cells were used as models of epithelial and neuronal cells respectively and qRT PCR technique was used for analyzing RNA levels of transcripts of spliced Xbp1, HERP, CHOP and BIP, selected target genes for three pathways of the UPR. HSV-1 DNA synthesis and infectious virus production in infected cells showed that compared to the permissive Vero cells, ONS-76 cells seemed to be semi-permissive to HSV-1 infection with limited viral DNA synthesis and infectious virus production. The kinetics of transcript and protein synthesis for genes representing immediate early, early and late classes of viral genes was also monitored. Expression of the immediate early gene, ICP0, was similar in both cell types but the expression of the early gene, TK and late genes VP16 and VP 5 was different. My work reveals that HSV-1 infection in cells of epithelial and neuronal origins results in activation of the UPR, but through cell type selective regulation of the three signal transduction pathways of the UPR (PERK, ATF6, and IRE-1). While HSV-1 infection resulted in upregulation of Spliced Xbp1 and its target gene HERP (IRE1 pathway) and downregulation of BIP (ATF6 pathway) in both cell types, CHOP (PERK pathway) was upregulated only in ONS cells. My results suggest that some aspects of the UPR are regulated differently in cells representing the sites for HSV-1 lytic and latent infections. This may indicate the need for increasing the capacity for protein folding and degradation (Xbp1 and ATF6-induced) in both cells but a requirement for suppressing apoptosis (PERK-induced) only in epithelial cells. As well, I show that HSV-1 infection not only selectively activates the UPR pathways in different cell types, but also inactivates some components of the UPR pathways activated by the drug thapsigargin.

No description available.

Bakgrund: Trycksår är ett stort problem för patienter och en enorm kostnad för samhället. Sjuksköterskan har ansvar att förebygga att dessa uppstår och hjälpa sårläkningen. Att sår och nutrition har ett samband har länge varit omdiskuterat. Syfte: Syftet med denna litteraturöversikt var att undersöka om läkningen av trycksår kan påverkas av oral nutritionsbehandling. Metod: Studiens metod var en deskriptiv litteraturöversikt där tio artiklar inkluderades och analyserades. Sökning efter artiklar gjordes i PubMed och Cinahl. Vid urval av artiklar lästes sammanfattningar och inklusions- och exklusionskriterier jämfördes mot den aktuella studiens kriterier. Inkluderade artiklar i litteraturöversikten lästes utförligt, analyserades och kategoriserades. Resultat: I de analyserade studierna återfanns resultat som visat på att oral nutritionsbehandling ger signifikant förbättring av trycksårens läkning. Sammanfattningsvis kan oral nutritionsbehandling påverka läkningen av trycksår. Det är oklart hur och på vilket sätt interventionerna påverkar läkningen. Ett samband kunde ses mellan de interventioner som innehöll arginin och zink. Dessa näringsämnen kan potentiellt påverka läkningen positivt. Slutsats: Enligt den här litteraturöversikten kan förbättrad läkning av trycksår ses i samband oral nutritionsbehandling. Dock finns ingen evidens och ytterligare forskning behövs inom området. / Background: Pressure ulcers are a big problem for patients and a huge cost for the tax-paying society. Nurses have a responsibility to prevent the ulcers from emerging and help with the wound healing. A correlation between wounds and nutrition has been debated. Objective: The objective with this overview was to see if the healing of pressure ulcers can be affected by oral nutritional interventions. Method: The method of this study was descriptive literature overview and ten articles were included and analyzed. Original articles were searched for in PubMed and Cinahl. To find the articles needed the abstracts were read and the inclusion- and exclusion criteria were compared to the present study’s criteria. The included articles in the overview were read thoroughly, analyzed and categorized. Result: In the studies that were analyzed there were results that showed that oral nutrition interventions give a significantly improved healing of the pressure ulcers. In summary, oral nutrition interventions can affect the healing of pressure ulcers. It is unclear how and which way the interventions may affect the healing. A correlation between the interventions containing arginine and zinc could be seen. These nutrients can potentially affect the healing of the ulcers positively. Conclusion: According to this literature overview improved healing of ulcers can be seen in combination with oral nutrition interventions. However no evidence was found and more research is needed in this area.

Mit dem Begriff Internet der Dinge (IOT) wird eine im Entstehen begriffene globale, Internet-basierte Architektur von Informationsdiensten bezeichnet, die Informationen Ÿber mit RFID-Chips versehene GegenstŠnde bereitstellt. Das IOT soll den Informationsaustausch Ÿber GŸter in in globalen Logistiknetzen erleichtern, ihre Transparenz erhšhen und somit Effizienzsteigerungen erreichen. Namensdienste fŸr das IOT sind verteilte Systeme, die bei Eingabe eines Identifikators fŸr einen Gegenstand, z.B. eines Elektronischen Produktcodes (EPC), eine Liste von Internetadressen fŸr Dienste zurŸckgeben, die weitere Informationen Ÿber den Gegenstand anbieten. Die vorliegende Arbeit hat die Herausforderungen an die Informationssicherheit von IOT-Namensdiensten (IOTNS) zum Thema. Hierbei leisten wir die folgenden ForschungsbeitrŠge: Erstens werden die Anforderungen an einen IOTNS herausgearbeitet, wobei insbesondere mehrseitige Sicherheit und die Perspektive der IOTNS-Clients berŸcksichtigt werden, die in den Standards und der Forschungsliteratur zum IOT bisher vernachlŠssigt worden sind. Zweitens fŸhren wir eine Sicherheitsanalyse des einflu§reichen Standards Object Naming Service (ONS) durch. Drittens werden Verbesserungen des ONS diskutiert, die einen Teil der ONS-Sicherheitsprobleme beheben kšnnten, ohne den etablierten Standard vollstŠndig zu verŠndern. Hierbei werden insbesondere eine Architektur fŸr Multipolares ONS und ihr Prototyp vorgestellt, bei der die internationale AbhŠngigkeit von dem Land reduziert werden kann, das den ONS-Root kontrolliert. Viertens prŠsentieren wir eine neue IOTNS-Architektur und ihre Implementierung auf der Forschungsplattform PlanetLab, die auf verteilten Hashtabellen basiert und von der gezeigt wird, dass sie verbesserte Sicherheitseigenschaften gegenŸber ONS aufweist -- bei vergleichbarem oder sogar erhšhtem Grad an FunktionalitŠt, Skalierbarkeit und Systemleistung. / The term Internet of Things (IOT) describes an emerging global, Internet-based information service architecture for RFID-tagged items (Radio-Frequency Identification). In the vision of its proponents, this IOT will facilitate information exchange about goods in global supply chain networks, increase transparency, and enhance their efficiency. Name Services for the IOT are distributed systems that serve the following fundamental lookup function: Given an identifier for a real-world object, e.g., an Electronic Product Code (EPC), they return a list of Internet addresses of services, which offer additional information about this object. This thesis discusses the information security challenges involved in the design and use of an IOT Name Service (IOTNS). Our main contributions are the following: First, the requirements for an IOTNS are collected and discussed, including multilateral security and the client perspective, which have been neglected in IOT standards and research literature so far. Second, we conduct a detailed security analysis of the most influential standard Object Naming Service (ONS). This extends our previous article that initiated this new research line in the field of RFID and IOT security. Third, enhancements to ONS are discussed, which could mitigate some of the ONS security shortcomings in an evolutionary way without completely abandoning the established standard. In particular, we describe an architecture and prototype for Multipolar ONS, which reduces international dependency on a single country controlling the ONS Root. Fourth, we present a new IOTNS architecture based on Distributed Hash Tables (DHT) and its implementation on the research platform PlanetLab. This architecture is shown to offer enhanced overall security compared to ONS while delivering equivalent or even better functionality, scalability, and performance.