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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.
11

Vliv aplikace přípravků pro zlepšení vitálních funkcí půdy na vybrané půdní vlastnosti v Agrovýzkum Rapotín s.r.o. / Influence of application of activators of vital soil functions on selected soil characteristics at Agrovýzkum Rapotín s.r.o.

Blaha, Josef January 2016 (has links)
This thesis describes and evaluates changes of selected physical properties using various excipients, manure and fertilizer. The first part is a literature review prepared for introduction to the soil and soil properties. Further analyzes the problem of soil improvers and their division. Selected soil substances are described in detail in some of the chapters. Subsequently describes some previous attempts substance PRP SOL. The evaluation of the impact on the application of the plant is working in Chapter 4 are listed first, soil and climatic conditions of the land block, which are made different versions of the test. Further I describe the evaluation of selected soil properties, which include, bulk density, soil moisture penetration resistance, infiltration capacity of soils and soil traction resistance when processing a disc harrow. The final chapter is devoted to a discussion of the assessed properties and the overall summary of the attempt.
12

Tunable Poly(ester urea)s for Tissue Engineering Applications

Childers, Erin P. January 2016 (has links)
No description available.
13

Biochemical Studies Of Interactions Between Prion Protein And Lipids

Wang, Fei 24 December 2008 (has links)
No description available.
14

Baltijos šalių vietinių avių veislių prioninio baltymo geno įvairovės tyrimai / Polymorphisms of prion protein gene in native baltic breeds of sheep

Volskienė, Rasa 15 December 2008 (has links)
Darbo tikslas – atlikti Baltijos šalių vietinių avių veislių: Estijos baltagalvių, Estijos juodgalvių, Estijos Ruhnu, Latvijos tamsiagalvių, Lietuvos vietinių šiurkščiavilnių, Lietuvos juodgalvių prioninio baltymo genetinės įvairovės tyrimus. Darbo uždaviniai: 1. Ištirti prioninio baltymo geno polimorfizmą 134, 157 ir 171 kodonuose, nustatyti šio geno alelius bei jų paplitimą Baltijos šalių vietinėse avių veislėse; 2. Nustatyti prioninio baltymo genotipų dažnius Baltijos šalių vietinių avių veislėse; 3. Identifikuoti prioninio baltymo genotipus pagal rizikos susirgti skrepi liga grupes, Baltijos šalių vietinių avių veislėse; 4. Sumodeliuoti atsparių skrepi ligai bandų formavimą pagal nustatytus prioninio baltymo genotipus bei jų paplitimo dažnį Baltijos šalių vietinėse avių veislėse. Pirmą kartą Baltijos šalių avių vietinėse veislėse: Estijos baltagalvių, Estijos juodgalvių, Estijos Ruhnu, Latvijos tamsiagalvių, Lietuvos vietinių šiurkščiavilnių, Lietuvos juodgalvių – buvo genotipuotas prioninio baltymo genas, identifikuoti šio geno aleliai, nustatytas jų paplitimas bei identifikuoti genotipai, pagal rizikos susirgti skrepi liga grupes. Atlikti prognoziniai skaičiavimai, siekiant suformuoti atsparių skrepi ligai avių bandas. / The aim of the work - to research prion protein gene(PrP) genetic diversity of local Baltic sheep in such breeds as Estonian whitehead, blackhead, and Ruhnu, Latvian darkhead, and Lithuanian coarsewool native, and Lithuanian blackface. Tasks of the research: 1. To investigate Prion protein gene polymorphism in 134, 157 and 171 codons, identify the gene alleles and their prevalence in the Baltic countries of the local native breeds of sheep; 2. To determine Prion protein genotype frequencies in the Baltic local native breeds of sheep; 3. To identify Prion protein genotypes according to the risk to contract scrapie disease in the native Baltic breeds of sheep; 4. To simulate scrapie resistant flocks according to the Prion protein genotypes and their prevalence rate in the native Baltic breeds of sheep. It is first time in the Baltics that the local sheep breed (Estonian whitehead, Estonian blackhead, Estonian Ruhnu, Latvian darkhead, Lithuanian coarsewool native, Lithuanian blackface) Prion protein gene was genotiped, gene alleles identified in their prevalence and genotypes classified into groups according to the risk to contract scrapie. The calculations were carried out in order to distinguish the groups of sheep resistant to scrapie.
15

Diferentes terapias na osteoartrite induzida por papaína em joelhos de ratos / Therapies in different osteoarthritis induced papain knees in rats

Rosseto, Laryssa Petrocini [UNESP] 26 February 2016 (has links)
Submitted by Laryssa Petrocini Rosseto null (laryssa_p@yahoo.com.br) on 2016-04-28T12:04:12Z No. of bitstreams: 1 Laryssa Petrocini Rosseto.pdf: 4052291 bytes, checksum: 412d5ee6bfab0c9a10573907db5a3e2d (MD5) / Approved for entry into archive by Felipe Augusto Arakaki (arakaki@reitoria.unesp.br) on 2016-05-02T12:04:23Z (GMT) No. of bitstreams: 1 rosseto_lp_me_jabo.pdf: 4052291 bytes, checksum: 412d5ee6bfab0c9a10573907db5a3e2d (MD5) / Made available in DSpace on 2016-05-02T12:04:23Z (GMT). No. of bitstreams: 1 rosseto_lp_me_jabo.pdf: 4052291 bytes, checksum: 412d5ee6bfab0c9a10573907db5a3e2d (MD5) Previous issue date: 2016-02-26 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Devido ao aumento da expectativa de vida dos animais e o crescente número de pessoas, a osteoartrite (OA), também conhecida como artrose, surge como uma das afecções mais relevantes na medicina veterinária e humana. Diversos tratamentos são utilizados e propostos, porém não há ainda consenso sobre a melhor terapia. Objetivou-se investigar e comparar a eficácia do Laser de baixa intensidade e o ultrassom terapêutico em conjunto com plasma rico em plaquetas (PRP), no tratamento da osteoartrite induzida em joelhos de ratos. Foram utilizados 72 ratos distribuídos aleatoriamente em nove grupos de oito animais: Grupo Controle (GC), Grupo solução fisiológica (GCF), Grupo osteoartrite 21 dias (GOA21), Grupo osteoartrite 42 dias (GOA42), Grupo osteoartrite e Laser (GOALa), Grupo osteoartrite e Ultrassom terapêutico (GOAUS), Grupo osteoartrite e PRP (GOAPrp), Grupo osteoartrite, PRP e Laser (GOAPrpLa) e Grupo osteoartrite, PRP e ultrassom terapêutico (GOAPrpUS). Foi realizada infiltração intra-articular de papaína 4% e cisteína 0,03M e, 21 dias após a indução, iniciou-se tratamento por três semanas com laser, ultrassom e/ou PRP. Foram realizadas avaliações perimétricas, termográficas, macro e microscópicas. Os resultados mostraram interação significativa entre os grupos em relação ao tempo para as avaliações perimétricas e termográficas, comprovando que a termografia foi eficaz para avaliar o comportamento da inflamação articular. Não foram observadas alterações macroscópicas na cartilagem articular em nenhum animal, fato este confirmado na avaliação histopatológica, onde evidenciou-se distensão e inflamação da cápsula articular, indicando a presença de sinovite. Com base nos resultados foi possível concluir que a aplicação de uma única dose de papaína 4% intra-articular não é suficiente para induzir a osteoartrite em joelhos de ratos, e sim sinovite. Além disso, os melhores resultados obtidos para a inflamação da sinóvia foram com o uso de PRP isolado ou combinado com laser. / Due to increasing life expectancy of animals and the growing number of people, osteoarthritis (OA), also known as arthrosis, appears as one of the most important diseases in veterinary and human medicine. Several treatments are use and proposed, but there is no consensus about the best therapy. This study aimed to investigate and compare the efficacy of Low-level laser therapy and therapeutic ultrasound in conjunction with platelet-rich plasma (PRP) in the treatment of osteoarthritis induced in rats’ knees. Randomly were used 72 mice divided into nine groups of eight animals: Control Group (CG), group saline (GCF), Group osteoarthritis 21 days (GOA21), Group osteoarthritis 42 days (GOA42), Group osteoarthritis and Laser (GOALa), Group osteoarthritis and therapeutic Ultrasound (GOAUS), osteoarthritis and PRP Group (GOAPrp), osteoarthritis Group, PRP and Laser (GOAPrpLa) and Group osteoarthritis, PRP and therapeutic ultrasound (GOAPrpUS). It was performed intra-articular infiltration of papain and cysteine 0.03M 4% and 21 days after the induction started three weeks treatment with laser, ultrasound and / or PRP. Evaluations were performed perimeter, thermographic, macro and microscopic. A significant interaction between the groups with respect to time to the perimeter and thermographic ratings, proving that thermography was effective to evaluate the behavior of articular inflammation. Macroscopic changes were observe in the articular cartilage in any animal, a fact confirmed in the histopathological evaluation, which showed up distension and inflammation of the joint capsule, indicating the presence of synovitis. Based on these results it was conclude that the application of a single dose of 4% papain intraarticular is not sufficient to induce osteoarthritis in the knees of mice, but synovitis. In addition, the best results to inflammation of the synovium were using PRP alone or in combination with a laser.
16

Analyse moléculaire du tissu adipeux humain en fonction de sa localisation anatomique et effet du PRP (Plateled Rich Plasma) sur les progéniteurs adipeux humains (ASCs) / Effects of Platelet-Rich Plasma on human adipose progenitors and molecular analysis of human adipose tissues according to their anatomic localisation

Chignon-Sicard, Bérengère 21 March 2018 (has links)
Différents domaines en Chirurgie Plastique et Esthétique ont évolué au cours de ces dernières années et notamment le transfert et injection de Tissu Adipeux autologue. Les premières données cliniques ont été présentées sans véritable appui scientifique. Cette thèse a pour objet de confirmer les données cliniques retrouvées et de permettre d’améliorer cette technique par des preuves scientifiques. Deux questions sont à considérer : 1) Le tissu adipeux a t-il selon son origine anatomique des caractéristiques différentes et certaines régions seraient-elles à privilégier lors d’une autogreffe ? 2) Existe t-il des facteurs de croissances autologues permettant de stimuler la prise de greffe, la prolifération et la différenciation des cellules greffées ? La première partie de ce travail a consisté à analyser le tissu adipeux en fonction du site de prélèvement. A cet effet, nous avons analysé le tissu adipeux provenant de 2 sites anatomiques : le genou et le menton. Le choix topographie découle d’une raison technique et d’une raison théorique. Nos résultats suggèrent que les deux sites étudiés ont des origines embryonnaires différentes, et montrent que ces deux sites présentent une signature moléculaire et une fonctionnalité différentes. La seconde partie porte sur l’effet in vitro de facteurs de croissances autologues humains. Nous avons analysé la prolifération et la différenciation de cellules souches adipogéniques (ASCs) humaines. Nous avons pour cela utilisé des concentrés plaquettaires issus de prélèvements sanguins autologues, et donc utilisables en pratique thérapeutique humaine. Il s’agit du PRF (plaquette riche en fibrine) et du PRP (plaquette riche en plasma). Les résultats de l’étude montrent que la présence de PRF ou de PRP dans le milieu de culture permet une augmentation drastique de la prolifération cellulaire d’environs 4 à 5 fois. A contrario, les résultats obtenus montrent un blocage partiel de la différenciation adipocytaire, quelque soit le moment et le temps de mise en contact. Nous avons alors étudié par quelle voie de blocage la différenciation était induit et avons montré l’implication de la voie du TGFB qui dans ces conditions de culture induit un blocage partiel de la différenciation des ASCs vers un adipocyte mature. Notre étude montre qu’en parallèle à l’effet antiadipogénique, la différenciation s’oriente vers des cellules myofibroblastes-like. Nous avons alors testé l’effet de l’ajout d’un inhibiteur du TGFB (SB431542) dans le milieu de culture et avons observé une relance de la différenciation cellulaire vers la voie adipogénique confirmant que le PRP a un effet antiadipogénique et promyofibroblastique. Par ailleurs, nous avons analysé la composition du PRP utilisé en dosant les taux de facteurs de croissance présents. En conclusion, ce travail permet de confirmer l’augmentation de la prolifération cellulaire des ASCs en présence de PRP autologue. Ceci nous permet donc une transposition clinique immédiate en utilisant en peropératoire l’association PRP et prélèvement de tissu adipeux lors d’un lipofilling. Ce travail permet également de mettre en lumière la probable différence de fonction des adipocytes prélevés en fonction de leur site anatomique d’origine. Ceci a probablement une conséquence sur l’évolution long terme de ces greffes de tissu adipeux en fonction d’une modification pondérale. / Different fields in plastic and aesthetic surgery have evolved in recent years including the transfer and injection of autologous adipose tissue. The first clinical data was presented without any real scientific support. The purpose of this thesis is to improve this technic by adding scientific evidence. There are two questions to consider: 1) Do adipose tissues have different characteristics according to their anatomical origin, and should certain regions be preferred for autografting? 2) Are there autologous growth factors to stimulate engraftment, proliferation and differentiation of grafted cells? The first part of this work consisted in analyzing the adipose tissue according to the fat depot. For this purpose, we analyzed the adipose tissues from 2 anatomical sites: the knee and the chin. The rational of this choice comes from a technical reason and a theoretical reason. Our results suggest that the two sites studied have different embryonic origins, and show that these two sites have a different molecular signature and functionality. The second part of the work deals with the in vitro effect of autologous human growth factors. on the proliferation and differentiation of human adipose stem cells (ASCs). For this purpose, we used platelet concentrates from blood samples, which can therefore be used in human therapeutic practice. It is the PRF (fibrin-rich platelet) and the PRP (platelet-rich plasma). The results of the study show that the presence of PRF or PRP in the culture medium allows a drastic increase in ASC proliferation of about 4 to 5 times. In contrast, the results show a partial inhibition of adipocyte differentiation, whatever the period and the time of contact. We analyzed the composition of different PRP sources and we identified the involvement of the TGFB pathway in the anti adipogenic effects of PRP. In contrast, the antiadipogenic effect was concomitant with the differentiation of ASCs towards myofibroblasts-like cells. In conclusion, this work allows us immediate clinical transposition using PRP during lipofilling. This work also makes it possible to highlight the probable difference in function of the adipocytes taken according to their original anatomical site. This likely has a consequence on the long term evolution of these adipose tissue grafts in case of a weight change.
17

Modelling prion-induced neurodegeneration in PrP transgenic Drosophila

Cardova, Alzbeta January 2019 (has links)
The aim of my thesis was to develop and characterise PrP transgenic Drosophila melanogaster of various genotypes to study the process of prion-induced neurodegeneration in this model. Prion diseases are caused by the occurrence of an abnormally-folded form of PrP (PrPSc) protein that arises either from the environment as an acquired disease, from mutation in the PrP-coding gene as a genetic disease or sporadically from causes unknown. The PrPSc then recruits PrPC, the normal form of PrP, that is ubiquitously present in the mammalian CNS and triggers neurotoxicity and neurodegeneration that is transmissible between individuals of the same or even different species. All prion diseases are currently incurable, fatal and the mechanism of prion-induced neurodegeneration remains to be discovered. In this thesis, Drosophila transgenic for ovine (chromosome 3 and dual PrP transgenic flies), hamster, humanised murine, human and cervid PrP were characterised for expression and biochemical properties. The ultimate goal of my thesis was investigation of cell-to-cell spread of misfolded PrP in Drosophila CNS. To achieve this, a mutant form of PrP that is thought to misfold was co-expressed with the normal form PrPC that served as a substrate in the same dual PrP-transgenic fly. The process was modelled using hamster, humanised murine or ovine PrP transgenes that carry human mutations associated with the spontaneous onset of transmissible neurodegeneration in the natural host. Various approaches towards independent spatial expression of PrP in Drosophila were exploited here in both single and dual PrP expressing flies. Moreover, the ability to initiate misfolding and the impact of this on the fly phenotype was investigated. Both apparent misfolding and phenotypic changes were seen in different fly models suggesting the models were successful. To this extent, PrP transgenic Drosophila were developed to allow for relatively rapid modelling of mammalian prion disease in this invertebrate organism.
18

A comparison of behavioural and functional neuroanatomical correlates of executive functions in multitasking and working memory

Otermans, Pauldy Cornelia Johanna January 2018 (has links)
This thesis aims to explore the role of executive functions in multitasking. Research has shown that severe performance decrements often arise in dual-task performance, also called multitasking, as compared to single task performance. This reflects a limitation in processing temporally overlapping information. Interference between tasks arises due to a bottleneck process limited to processing only one task at a time. It has been proposed that this interference is resolved by executive functions. However, the dual-task paradigm employed in this thesis, Psychological Refractory Period (PRP) paradigm, (Pashler, 1994) is typically investigated in the field of human action performance, and the exact concept of executive functions remains underspecified. However, while underspecified in the area of action performance, executive functions have been investigated in detail in the field of memory research, more specifically in the context of working memory (WM). Therefore, the aim of this thesis was to investigate whether the executive functions in PRP are related to the executive functions as discussed in the context of WM. To test this question, we combined the PRP paradigm with a WM task, creating a complex WM span task. If the executive functions of WM and PRP are indeed related, then an interaction between the two tasks should be evident. Participants were presented with a sequence of letters to remember, followed by a processing block in which they had to perform either a single task or a dual-task, and finally were asked to recall the letters. Results (Chapter 2) showed that recall performance decreased when performing a dual-task as compared to performing a single task. This supports the assumption that PRP dual-tasks demand executive functions of WM. Following this, two other experiments were performed each with a different parametric modulation of the processing demands of the PRP dual task; response order (fixed vs random; Chapter 3) and stimulus onset asynchrony (SOA, short vs long; Chapter 4) of the component tasks. Recall performance was lower after a more difficult dual-task compared to an easier dual-task, which again indicates that demands on executive functions are increased in the dual-task. While previous neuroscientific research indeed showed that dual-tasks as well as WM tasks rely on lateral-prefrontal cortices (LPFC), it remains unknown whether both tasks activate the same areas or different sub-areas of the LPFC. Therefore, this study (Chapter 6) investigated how the neuroanatomical correlates of both dual-task and WM compare to each other. The brain activation for the PRP and WM tasks showed considerable overlap as well as some differentiation. Both tasks activated, among other areas, the inferior frontal junction. With respect to differences, the PRP task activated more the inferior middle frontal gyrus (MFG) whilst the WM component activated more the superior MFG. Thus, results support the assumption that PRP dual-tasks demand the executive functions of WM. This will allow us to inform theoretical models of cognition and to get a better understanding of human cognition. Future studies can build on this in order to create a more consolidated conceptualisation of the relationship between WM and multitasking.
19

Prion Protein is Expressed on Long-term Repopulating Hematopoietic Stem Cells and is Necessary for their Self-renewal

Lodish, Harvey F., Zhang, Cheng Cheng, Steele, Andrew D., Lindquist, Susan L. 01 1900 (has links)
We show that the prion protein (PrP) is expressed on the surface of bone marrow cell populations enriched in long-term repopulating hematopoietic stem cells. Affinity purification of the PrP-positive and PrP-negative fractions from these populations, followed by competitive reconstitution assays, show that all long-term repopulating hematopoietic stem cells express PrP. Hematopoietic stem cells from PrP null bone marrow exhibit impaired self-renewal in serial competitive transplantation experiments, and premature exhaustion when exposed to cell cycle-specific myelotoxic injury. Therefore, PrP is a novel marker for hematopoietic stem cells and regulates their self-renewal. / Singapore-MIT Alliance (SMA)
20

Investigations into the Significance of the Evolutionary Descent of Prion Genes from Ancestral Zip Transporter

Salehzadeh, Ashkan 04 December 2012 (has links)
The conformational conversion of the cellular prion protein (PrPC) to PrP scrapie (PrPSc) is a hallmark of prion diseases [1]. The cellular role of PrP and the mechanism of PrPSc neurotoxicity remain largely elusive. Therefore, the identification of new prion-like proteins can assist in revealing the function of PrP. A recent study identified a sub-branch of ZIP (Zrt-, Irt-like protein) metal transporters, including ZIP5, ZIP6 and ZIP10, to be evolutionarily related to PrP. This thesis attempts to understand the functional relevance of this relationship between PrP and ZIP transporters with regard to PrP pathobiology. Preliminary observations indicated that PrP, ZIP6 and ZIP10 underwent endoproteolysis in scrapie-infected mouse brains. PrP and ZIP10 processing mimicked the proteolysis which occurs in cell culture during zinc-deficient conditions, suggesting that scrapie infection may be associated with zinc deficiency. More work is needed to uncover whether ZIPs can contribute to the propagation of prion diseases.

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