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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Tissue engineering techniques to regenerate articular cartilage using polymeric scaffolds

Pérez Olmedilla, Marcos 18 December 2015 (has links)
[EN] Articular cartilage is a tissue that consists of chondrocytes surrounded by a dense extracellular matrix (ECM). The ECM is mainly composed of type II collagen and proteoglycans. The main function of articular cartilage is to provide a lubricated surface for articulation. Articular cartilage damage is common and may lead to osteoarthritis. Articular cartilage does not have blood vessels, nerves or lymphatic vessels and therefore has limited capacity for intrinsic healing and repair. Tissue engineering (TE) is a powerful approach for healing degenerated cartilage. TE uses three-dimensional (3D) scaffolds as cellular culture supports. The scaffold provides a structure that facilitates chondrocyte adhesion and expansion while maintaining a chondrocytic phenotype and limiting dedifferentiation, which is a problem in two-dimensional (2D) systems. Cell attachment to the scaffolds depends on the physical and chemical characteristics of their surface (morphology, rigidity, equilibrium water content, surface tension, hydrophilicity, presence of electric charges). The primary aim of this thesis was to study the influence of different kinds of biomaterials on the response of chondrocytes to in vitro culture. 3D scaffold constructs must have an interconnected porous structure in order to allow cell development through the network, to maintain their differentiated function, as well as to allow the entry and exit of nutrients and metabolic waste removal. Therefore, the effect of the hydrophilicity and pore architecture of the scaffolds was studied. A series of polymer and copolymer networks with varying hydrophilicity was synthesised and biologically tested in monolayer culture. Cell viability, proliferation and aggrecan expression were quantified. When human chondrocytes were cultured on polymer substrates in which the hydrophilic groups were homogeneously distributed, adhesion, proliferation and viability decreased with the content of hydrophilic groups. Nevertheless, copolymers in which hydrophilic and hydrophobic domains alternate showed better results than the corresponding homopolymers. Biostable and biodegradable scaffolds with different hydrophilicity and porosity were synthesised using a template of sintered microspheres of controlled size. This technique allows the interconnectivity between pores and their size to be controlled. Periodic and regular pore architectures and reproducible structures were obtained. The mechanical behaviour of the porous samples was significantly different from that of the bulk material of the same composition. Cells fully colonised the scaffolds when the pores' size and their interconnection were sufficiently large. Another objective was to assess the chondrogenic redifferentiation in a biodegradable 3D scaffold of polycaprolactone (PCL) of human autologous chondrocytes previously expanded in monolayer. This study demonstrated that chondrocytes cultured in PCL scaffolds without fetal bovine serum (FBS) efficiently redifferentiated, expressing a chondrocytic phenotype characterised by their ability to synthesise cartilage-specific ECM proteins. The influence that pore connectivity and hydrophilicity of caprolactone-based scaffolds has on the chondrocyte adhesion to the pore walls, proliferation and composition of the ECM produced was studied. The number of cells inside polycaprolactone scaffolds increased as porosity was increased. A minimum of around 70% porosity was necessary for this scaffold architecture to allow seeding and viability of the cells within. The results suggested that some of the cells inside the scaffold adhered to the pore walls and kept the dedifferentiated phenotype, while others redifferentiated. In conclusion, the findings of this thesis provide valuable insight into the field of cartilage regeneration using TE techniques. The studies carried out shed light on the right composition, porosity and hydrophilicity of the scaffolds to be used for optimal cartilage production. / [ES] El cartílago articular es un tejido compuesto por condrocitos rodeados por una densa matriz extracelular (MEC). La MEC se compone principalmente de colágeno tipo II y de proteoglicanos. La función principal del cartílago articular es proporcionar una superficie lubricada para las articulaciones. Las lesiones en el cartílago articular son comunes y pueden derivar a osteoartritis. El cartílago articular no tiene vasos sanguíneos, nervios o vasos linfáticos y, por tanto, tiene una capacidad limitada de auto-reparación. La ingeniería tisular (IT) es un área prometedora en la regeneración de cartílago. En la IT se utilizan "andamiajes" (scaffolds) tridimensionales (3D) como soportes para el cultivo celular y tisular. Los scaffolds proporcionan una estructura que facilita la adhesión y la expansión de los condrocitos, manteniendo un fenotipo condrocítico limitando su desdiferenciación; que es el mayor problema en los sistemas bidimensionales (2D). La adhesión celular a los scaffolds depende de las características físicas y químicas de su superficie (morfología, rigidez, contenido de agua en equilibrio, tensión superficial, hidrofilicidad, presencia de cargas eléctricas). El objetivo general de esta tesis fue estudiar la influencia de diferentes tipos de biomateriales en la respuesta de los condrocitos en cultivo in vitro. Los scaffolds deben tener una estructura porosa interconectada para permitir el desarrollo celular a través de toda la estructura 3D, potenciando que los condrocitos mantengan su fenotipo, así como permitiendo entrada de nutrientes y eliminación de desechos metabólicos. Se estudió el efecto de la hidrofilicidad y de la arquitectura de poro. Se cuantificó la viabilidad celular, la proliferación y la expresión de agrecano. Cuando los condrocitos humanos se cultivaron en sustratos poliméricos donde los grupos hidrófilos se distribuyeron de manera homogénea, la adhesión, la proliferación y la viabilidad disminuyó con el contenido de grupos hidrófilo. Sin embargo, los copolímeros en los que los dominios hidrófilos e hidrófobos se alternaban mostraron mejores resultados que los homopolímeros correspondientes. Se sintetizaron series de scaffolds bioestables y series biodegradables con diferente hidrofilicidad y porosidad utilizando plantillas de microesferas sinterizadas. Se obtuvieron arquitecturas de poros regulares y reproducibles. Las células colonizaron el scaffold en su totalidad cuando los poros y la interconexión entre ellos era lo suficientemente grande. Se evaluó la rediferenciación condrogénica de condrocitos autólogos humanos, previamente expandidos en monocapa, sembrados en un scaffold biodegradable de policaprolactona (PCL). Se demostró que los condrocitos cultivados en scaffolds de PCL con medio sin suero bovino fetal (FBS), se rediferenciaban de manera eficiente; expresando un fenotipo condrocítico, caracterizado por su capacidad de sintetizar proteínas de la MEC específicas de cartílago hialino. Se estudió la influencia de la hidrofilicidad y la conectividad de los poros de los scaffolds de caprolactona sobre la adhesión de los condrocitos a las paredes de los poros, su capacidad proliferativa y la composición de MEC sintetizada. Se observó que un mínimo de 70% de porosidad era necesario para permitir la siembra de los condrocitos en el scaffold y su posterior viabilidad. El número de células aumentaba a medida que aumentaba la porosidad del scaffold. Los resultados sugieren que parte de las células que se adherían a las paredes internas de los poros mantenían el fenotipo desdiferenciado de condrocitos cultivados en monocapa, mientras que otros se rediferenciaban. En conclusión, los resultados de esta tesis aportan un avance en el campo de la regeneración de cartílago articular utilizando técnicas de IT. Los estudios realizados proporcionan directrices sobre la composición, la porosidad y la hidrofilicidad más adecuada para l / [CAT] El cartílag articular és un teixit format per condròcits envoltats per una densa matriu extracel·lular (MEC). La MEC es compon principalment de col·lagen tipus II i de proteoglicans. La funció principal del cartílag articular és proporcionar una superfície lubricada a les articulacions. Les lesions en el cartílag articular són comuns i poden derivar en osteoartritis. El cartílag articular no té vasos sanguinis, nervis ni vasos limfàtics i, per tant, té una capacitat limitada d'auto-reparació. L'enginyeria tissular (IT) és una àrea prometedora en la regeneració del cartílag. A la IT s'utilitzen "bastiments" (scaffolds) tridimensionals (3D) com a suports per al cultiu cel·lular i tissular. Els scaffolds proporcionen una estructura que facilita l'adhesió i l'expansió dels condròcits, mantenint un fenotip condrocític limitant la seua desdiferenciació; que és el major problema en els sistemes bidimensionals (2D). L'adhesió cel·lular als scaffolds depèn de les característiques físiques i químiques de la superfície (morfologia, rigidesa, contingut d'aigua en equilibri, tensió superficial, hidrofilicitat i presència de càrregues elèctriques). L'objectiu general d'aquesta tesi va ser estudiar la influència de diferents tipus de biomaterials en la resposta dels condròcits en cultiu in vitro. Els scaffolds han de tindre una estructura porosa interconnectada per a permetre el desenvolupament cel·lular a través de tota l'estructura 3D, potenciant que els condròcits mantinguen el seu fenotip així com permetent l'entrada de nutrients i l'eliminació de productes metabòlics. S'ha estudiat l'efecte de la hidrofilicitat i de l'arquitectura de porus dels scaffolds. Es va quantificar la viabilitat cel·lular, la proliferació i l'expressió de agrecà. Quan els condròcits humans es van cultivar en substrats polimèrics en els quals els grups hidròfils es van distribuir de manera homogènia, l'adhesió, la proliferació i la viabilitat van disminuir amb el contingut de grups hidròfils. No obstant això, els copolímers en els quals els dominis hidròfils i hidròfobs s'alternaven van mostrar millors resultats que els homopolímers corresponents. Es van sintetitzar sèries de scaffolds bioestables i sèries biodegradables amb diferent hidrofilicitat i porositat utilitzant plantilles de microesferes sinteritzades. Es van obtindre arquitectures de porus regulars i reproduïbles. Les cèl·lules van colonitzar el scaffold en la seua totalitat quan els porus i la interconnexió entre ells era suficientment gran. Es van avaluar la rediferenciació condrogènica de condròcits autòlegs humans, prèviament expandits en monocapa, en un scaffold biodegradable de policaprolactona (PCL). Es va demostrar que els condròcits cultivats en scaffolds de PCL sense sèrum boví fetal (FBS) es rediferenciaven de manera eficient, expressant un fenotip condrocític caracteritzat per la seua capacitat de sintetitzar proteïnes de la MEC específiques de cartílag hialí. També es va estudiar la influència de la hidrofilicitat i la connectivitat dels porus dels scaffolds de caprolactona sobre l'adhesió dels condròcits a les parets dels porus, la seua capacitat proliferativa i la composició de MEC sintetitzada. Es va observar que un mínim del 70% de porositat sembla ser necessari per permetre la sembra dels condròcits i la seua posterior viabilitat en el scaffold. El nombre de cèl·lules augmentava a mesura que augmentava la porositat del scaffold. Els resultats suggereixen que part de les cèl·lules que s'adherien a les parets internes dels porus mantenien el fenotip desdiferenciat de condròcits cultivats en monocapa, mentre que altres es rediferenciaven. En conclusió, els resultats d'aquesta tesi proporcionen informació valuosa en el camp de la regeneració de cartílag utilitzant tècniques d'IT. Els estudis realitzats proporcionen directrius sobre la composició, la porositat i la hidrofilicitat m / Pérez Olmedilla, M. (2015). Tissue engineering techniques to regenerate articular cartilage using polymeric scaffolds [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/58987 / TESIS
62

Efekt přítlaku vyvozovaného na elektrodový systém olověného akumulátoru s experimentálními elektrodami / The effect of pressure on the electrode system in lead acid batteries with experimental electrodes

Zabloudil, Ondřej January 2014 (has links)
This Master’s thesis deals with the issue of lead-acid batteries, which are used in hybrid electric vehicles. The lead-acid batteries works in mode PSoC. In this mode occurs to degradation mechanisms at negative electrodes. These degradation mechanisms reduce the battery life. The practical part of Master’s thesis describes the production and a compilation of experimental cells and experimental part examines the characteristics of lead-acid batteries with the pressure to the electrode system.
63

Innate Confinement Effects in PCL Oligomers as a  Route to Confined Space Crystallisation

Sanandaji, Nima January 2009 (has links)
In this work, an in-depth analysis of crystalline characteristics has been performed for a unique set of strictly monodisperse poly-ε-caprolactone (PCL) oligomers. The molecules have different sets of end groups with various degrees of bulkiness and hydrogen bonding potential, affecting their aptitude to pack in ordered crystal structures. The oligomers also have different numbers of repeating units (n = 2-64), affecting the degree to which end groups influence overall molecular characteristics. The presence of bulky end groups leads to an innate confinement effect on crystallisation which in turn makes it possible to utilize the set of PCL oligomers to study confined space crystallisation. Confined space crystallisation is explored as a route to gain further understanding about the early metastable phases in crystal formation.   The monodisperse nature of the samples made it possible to collect very precise small-angle and wide-angle X-ray scattering data (SAXS and WAXS) as well as calorimetric data. Computer modeling studies were performed to support experimental findings. It was shown that end groups strongly affected crystallisation features for the shorter oligomers (n ≤ 8) but to a lesser extend for the longer oligomers (n ≥ 16). The presence of a bulky end group at one end of an oligomer could inhibit the formation of hydrogen bonds on the other end. Short oligomers (n = 8) with OH-end groups exhibited novel packing characteristics. At one isothermal crystallisation temperature the molecules exhibited not only lamellar ordering but also an additional, likely rectangular or slanted, ordering. The sample was packed in a unique structure with molecular chains lying parallel but not aligned head to head with each other. At a higher crystallisation temperature the molecules packed in a double layered structure and at an even higher temperature in a typical non-folded but tilted single-molecular layer pattern.   Unit cell determination was performed for a short oligomer with two bulky end groups, showing the existence of a tetragonal unit cell with different dimensions than the orthorhombic unit cells previously reported for linear PCL without end groups. To gain greater insight into the earliest stages of molecular packing, in situ WAXS measurements were performed using a synchrotron radiation beam and measuring data each 12 s whilst very slowly going from melt to isothermal crystallisation. It was shown that the crystal unit cell was distorted during the first minutes of slow crystallisation, which might either represent a metastable phase or else a highly distorted orthorhombic phase. / QC 20101105
64

Validizace nástroje na měření traumatu: PTSD Checklist pro DSM-5 / Validation of trauma measurement tool: PTSD Checklist for DSM-5

Miklóš, Jessica January 2021 (has links)
This thesis focuses on the initial validation of the PTSD Checklist for DSM-5 (PCL-5) in its Czech version. It is a self-report method that measures symptoms accompanying posttraumatic stress disorder (PTSD). The theoretical part of the thesis describes the development of the diagnosis of PTSD over time and its current criteria. It also presents a list of diagnostic tools for measuring PTSD, including the PCL-5 and its psychometric properties. The research part of the thesis describes the process of data collection and processing, the results of the hypotheses and discussion. The research sample consisted of 444 respondents (370 women; 74 men) with a mean age of 32,6 years (SD = 10,6). The mean PCL-5 score was 29,3 (SD = 19,9). When comparing the scores of women (M = 30,2; SD = 20) and men (M = 24,7; SD = 18,8), a statistically significant difference was observed (p = 0,029). When comparing respondents who were psychiatric patients (PP; M = 39,5; SD = 20) and those who were not (M = 21,7; SD = 16,6), a significant difference (p < 0,001) was also observed. In case of comparison of respondents by gender who were not PP, no statistically significant difference was confirmed. Cronbach's alpha for the whole questionnaire came out high: 0,955 (for clusters ranging from 0,831-0,908), which is consistent...
65

Psychopathy and Gender of Serial Killers: A Comparison Using the PCL-R.

Norris, Chasity Shalon 17 August 2011 (has links) (PDF)
Psychopathy and serial murder are 2 of society's most devastating and least understood tribulations. Even less is comprehended with regards to the differences in the way these ills are expressed between the genders. In this study, psychopathic personality traits are considered in a sample comparison of male and female serial murderers. Traits are measured using questions derived from Hare's Psychopathy Checklist Revised (PCL-R, 1991). A content analysis was performed to score the components for each subject, using known and accepted biographical and personal interview materials. Findings showed a distinct difference between the sexes, with females scoring lower than their male counterparts, indicating that factor structure of the PCL-R may need to be restructured in regards to females. Implications for public policy including the way female psychopathy is viewed and diagnosed are reviewed.
66

Nano-Graphene Oxide Surface-Functionalized Poly(e-caprolactone) Scaffolds with Drug Delivery Capability

Jenevieve Linell, Yao January 2018 (has links)
Grafenoxid (GO) ar en lovande kandidat som nano-tillsats i medicinska byggnadsstallningar for benregenerering. GO kan forbattra den biologiska kompatibiliteten och osteogena prestandan hos polymerbaserade byggstallningar, och ocksa vasentligt bidra till forbattringen av materialets mekaniska egenskaper. I detta arbete ympades nano-grafenoxid (nGO) kovalent pa ytan av poly (e-kaprolakton) (PCL) genom att fdrst modifiera polymerytan via aminolys. Med anvandning av 1,6-hexandiamin / isopropanol infordes fria amingrupper framgangsrikt pa PCL-ytan for efterfoljande immobilisering av nGO. En optimerad ympningsprocess utvecklades via en losningsmedelsassisterad metod med vatten som losningsmedel for att kovalent binda nGO pa ytan av PCL byggnadsstallningar. De initiala nGO koncentrationerna var 0,5 och 1 mg / ml. fourier-transform infrarodspektroskopi (FTIR) och termogravimetrisk analys (TGA) verifierade bindningen mellan de funktionella gruppema pa nGO och de fria aminema. Svepelektronmikroskopi (SEM) visade en homogen fordelning av nGO pa ytan av de porosa byggnadsstallningarna. De mekaniska testema som utfordes demonstrerade · en 50 och 21 % okning av kompressionsstyrkan :for byggnadsstallningarna ympade med de initiala nGO-koncentrationema pa 0,5 och 1 mg / ml. In vitro-mineraliseringstester visade bildandet av mineralfallningar pa ytan av byggnadsstallningama som okade i storlek med hogre nGO-halt. A ven nGO: s potential som nano-barare av ett antibiotikum studerades i detta arbete. Pa grund av sitt overflod av kemiska funktionaliteter kan nGO effektivt adsorbera foreningar genom olika sekundara interaktioner. I denna studie optimerades dessa sekundara interaktioner genom att reglera losningens pH for maximal adsorption av ciprofloxacin, ett bredspektrum antibiotikum som anvands vid behandling av osteomyelit. Ciprofloxacin befanns kunna adsorberas starkast i sin katjonform vid pH 5, dar 1t-1t elektron­donatoracceptor (EDA) -interaktioner dominerar. Sammanfattningsvis bekraftar de resultat som presenteras i detta arbete potentialen hos nGO som egenskapsforbattrare och lakemedelsbarare i applikationer inom vavnadsregenerering. / Graphene oxide (GO) is a promising candidate as nano-filler material in scaffolds for bone regeneration. It has been demonstrated to enhance the biological compatibility and osteogenic performance of polymer-based scaffolds, aside from its substantial contribution to the improvement of the material's mechanical properties. In this work, nano-graphene oxide (nGO) was covalently grafted to the surface of poly( e-caprolactone) (PCL) by first modifying the polymer surface via aminolysis. Using 1,6-hexanediamine/isopropanol, free amine groups were successfully introduced to the PCL surface for the subsequent immobilization of nGO. An optimized grafting pathway, which implements the solvent-assisted method and uses water as a solvent, was developed to covalently attach nGO using initial concentrations of 0.5 and 1 mg/mL. Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) both verified the successful attachment of nGO through the free amines. Scanning electron microscopy (SEM) depicts a homogeneous dispersion of nGO over the polymer matrix. Mechanical tests were performed and demonstrate a 50 and 21 % increase in compressive strength for the scaffolds grafted using initial nGO concentrations of 0.5 and 1 mglmL. In vitro mineralization tests showed the formation of mineral precipitates on the surface of the scaffolds that increased in size with higher nGO content. The potential of nGO as a nano-carrier of an antibiotic drug was also explored in this work. As it comprises of an abundance of chemical functionalities, nGO is able to efficiently adsorb compounds through various secondary interactions. In this study, these secondary interactions were optimized by controlling the solution pH for the maximum adsorption of ciprofloxacin, a broad-spectrum antibiotic used in the treatment of osteomyelitis. Ciprofloxacin was found to be adsorbed most strongly in its cationic form at pH 5, in which 1t-1t electron-donor acceptor (EDA) interactions predominate. Overall, the results presented in this work validate the potential of nGO as nano-enhancer and drug carrier in tissue engineering scaffold applications.
67

In-Domain and Cross-Domain Classification of Patronizing and Condescending Language in Social Media and News Texts : A Study in Implicitly Aggressive Language Detection and Methods

Ortiz, Flor January 2022 (has links)
The field of aggressive language detection is developing quickly in Natural Language Processing. However, most of the work being done in this field is centered around explicitly aggressive language, whereas work exploring forms of implicitly aggressive language is much less prolific thus far. Further, there are many subcategories that are encompassed within the greater category of implicitly aggressive language, for example, condescending and patronizing language. This thesis focuses on the relatively new field of patronizing and condescending language (PCL) detection, specifically on expanding away from in-domain tasks that focus on either news or social media texts. Cross-domain patronizing and condescending language detection is as of today not a widely explored sub-field of Natural Language Processing. In this project, the aim to answer three main research questions: the first is to what extent do models trained to detect patronizing and condescending language in one domain, in this case social media texts and news publications, generalize to other domains. Secondly, we aim to make advances toward a baseline for balanced PCL datasets and compare performance across label distribution ratios. Thirdly, we aim to address the impact of a common feature in patronizing and condescending language datasets--the significant imbalance between negative and positive labels in the binary classification task. To this end, we aim to address the question of to what extent does the proportion between labels have an impact on the in-domain PCL classification task.  We find that the best performing model for the in-domain classification task is the Gradient Boosting classifier trained on an imbalanced dataset harvested from Reddit, which included both the post and the reply, with a ratio of 1:2 between positive and negative labels. In the cross-domain task, we find that the best performing model is an SVM trained on the balanced news dataset and evaluated on the balanced Reddit post and reply dataset. In the latter study, we show that it is possible to achieve competitive results using classical machine models on a nuanced, context-dependent binary classification task.
68

Mindfulness vid PTSD - En systematisk litteraturstudie och metaanalys

Paavola, Marianne, Räihä, Marie January 2023 (has links)
Mindfulness används ofta i samband med behandling för depressioner och ångest för att lindra stress hos patienter. Det finns dock inte någon entydig forskning om mindfulness förbättrar måendet för patienter med PTSD. Här har en systematisk genomgång samt metaanalys genomförts för att avgöra om mindfulnessbaserade interventioner har någon inverkan på att lindra symtomen för PTSD. Systematiska sökningar har genomförts i olika databaser som PubMed, Medline, CINAHL och APA för att hitta relevanta randomiserade kontrollerade studier, som är publicerade under de senaste sju åren. Två författare genomförde litteratursökningen oberoende av varandra, samlade in data samt utförde den statistiska analysen. Metaanalysen omfattade 5 studier med 317 deltagare. Samtliga studier använde sig av PCL-5 som mätvärde för PTSD. Behandlingstiden varierade mellan fyra ochåtta veckor. Metaanalysen redovisar före- och eftermätningar av mindfulnessbehandlingarutan att ta med uppföljande mätningar. Resultaten visade att mindfulnessbaserade interventioner hade måttlig effekt (Cohens d = 0.63, 95 % CI: 0.42 – 0.82) gällande att lindra PTSD-symptom jämfört med behandling som vanligt (TAU), ”present-centered group therapy” och väntelista. Enligt den forskning vi sett kan mindfulnessbaserade interventioner vara till nytta för patienter som diagnostiserats med PTSD. Vår metaanalys visar att mindfulness kan vara ett effektivt sätt att minska PTSD-symptom och ge en ökad livskvalitet. Behandlingslängd, antal sessioner och PTSD-graden verkar ha mindre effekt än interventionens innehåll.  Nyckelord: metaanalys, mindfulness, PTSD, PCL, vuxna / Mindfulness is often used in conjunction with treatment for depression and anxiety to relieve stress in patients. However, there is no clear research on whether mindfulness improves the well-being of patients with PTSD. A systematic review and meta-analysis has been conducted to determine whether mindfulness-based interventions have any effect on alleviating the symptoms of PTSD. Systematic searches were conducted in various databases such as PubMed, Medline, CINAHL and APA to find relevant randomized controlled trials, which are published in the last seven years. Two authors independently conducted the literature search, collected the data and performed the statistical analysis. The meta-analysis included 5 studies with 317 participants. All studies use the PCL-5 as a measure of PTSD. The treatment time varied between four to eight weeks. The meta-analysis reports pre- and post-measurements of mindfulness treatments without including follow-up measurements. Results showed that mindfulness-based interventions had moderate effect ((Cohens d = 0.63, 95 % CI: 0.42 – 0.82) in alleviating PTSD symptoms compared to treatment as usual (TAU), present-centered group therapy and waiting list. According to the research we have seen, mindfulness-based interventions can be beneficial for patients diagnosed with PTSD. Our meta-analysis shows that mindfulness can be an effective way to reduce PTSD symptoms and provide an increased quality of life. Duration of treatment, number of sessions and the degree of PTSD appear to have less effect than the content of the intervention. Keywords: meta-analysis, mindfulness, PTSD, adults
69

SURFACE FUNCTIONALIZATION OF MELT COEXTRUDED FIBERS FOR BIOMEDICAL APPLICATIONS

Kim, Si Eun 08 February 2017 (has links)
No description available.
70

Efficient Drug and Nucleic Acid Delivery Systems based on Synthetic Amphiphiles with Tuned Oil/Water Interfaces

Satyal, Uttam January 2018 (has links)
Today, drugs are an integral part of healthy human life, with new drug entities being introduced every year in clinic. The advancement of drug development brings complexity and variation, in terms of both physical and chemical properties. Some of these physicochemical characteristics are many times suboptimal, eventually requiring robust delivery systems that can precisely deliver the drugs to the desired tissues. Although many materials have been studied for the generation of drug delivery systems, there is always a need for biomaterials with better properties that can translate into superior delivery systems. In this context, new drug delivery systems that are interface-engineered at materials level for better stability and delivery efficiency in vitro and in vivo are introduced in this dissertation. In the first part of the dissertation, novel oil/water interface-engineered amphiphilic block copolymer micelles that were previously introduced by our lab were assessed for their stability in the presence of various esterase enzymes present in serum and on blood vessel walls, normally encountered by drug delivery systems on route to the targeted tissues. I also assessed the vulnerability of the polymeric micelles in presence of enzymes typically present either inside the tumor cells or secreted in the tumor microenvironment. I revealed the selective stability of empty- and docetaxel-loaded polymeric micelles to enzymatic degradation en route/in tumors and I have correlated this selective stability with polymer structure and interfacial engineering mentioned above. The unique delivery capabilities of interfacial-engineered polymeric micelles were tested in vivo using a mouse model of triple negative breast cancer. We proved that our novel engineered triblock copolymer-based drug delivery systems are superior to similar delivery systems made out of standard diblock copolymer micelles and also to the clinically used Taxotere® formulation towards cancer cell killing and tumor treatment, without displaying any significant toxicity in experimental animals. The second part of the dissertation focuses on the development and assessment of a pyridinium-based pseudo-gemini surfactant that combined the high nucleic acid packaging capacity of pyridinium lipids with the high transfection efficiency of gemini surfactants while displaying a reduced associated cytotoxic effect. I have analyzed the temperature treatment on compaction of nucleic acids into lipoplexes and I have established a high temperature annealing method for this purpose. This novel formulation technique allowed a substantial reduction of the amount of amphiphiles required to compact a specific amount of nucleic acids. This in turn also reduced the cytotoxic effect associated with the use of pyridinium amphiphiles. The effect of inclusion of colipids to lipoplex compaction, the robustness and the transfection efficiency of the lipid/nucleic acid lipoplex systems were assessed in detail, and correlations between formulation composition and biological activity were established. I was also able to show for the first time that pyridinium pseudo-gemini surfactants were able to compact different types of nucleic acids, including pDNA, mRNA and siRNA at lower charge ratios than standard, state-of-the art formulations used for this purposes. I also showed that irrespective to the nucleic acid compacted within the lipoplexes, the novel amphiphiles can efficiently deliver the cargo into the targeted cells even in the presence of very high concentration of serum, a premise for future use of these amphiphiles and formulations in vivo. / Pharmaceutical Sciences

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