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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.
321

Nové metodiky kombinace hmotnostní spektrometrie (MS) se světlem aktivovaným povrchovým značením, elektronovým přenosem nebo síťovaním (PIXL) / The novel combinations of experimental approaches: mass spectrometry (MS) and photo-induced surface labelling, electron release (PIER), or cross-linking (PIXL)

Tuzhilkin, Roman January 2020 (has links)
Countless electron transport/transfer (ET) processes occur in living organisms every day. Therefore, their study is a crucial field of modern structural and functional proteomics. In many cases model proteins like azurin from P. aeruginosa are utilised in experiments. This blue copper protein is favoured due to a characteristic absorbance maximum at 630 nm in Cu(II) redox state of the central Cu atom. During its oxidation to Cu(I) state the A630 value decreases allowing UV-Vis detection of ET reaction progress. We have introduced a structural photoinducible analogue of canonical amino acid Met - L-2-amino-5,5-azihexanoic acid (photo-Met) - into azurin structure to study oligomerization in solution via photo-induced cross-linking (PIXL). Using previously optimised protocols for recombinant expression in E. coli B834 we have inserted photo-Met into azurin moieties: wild type azurin and Az2W mutant where two adjacent W residues with confirmed role in electron hopping across protein-protein interface are present. The incorporation percentage of photo-Met in analysed samples was determined after SDS-PAGE and in-gel protease digestion via MALDI-TOF MS. PIXL was employed to study azurin-azurin interaction and oligomerization under different total concentrations of protein (in range of 15-300 µM). The...
322

Kontroverze obrazu ve veřejném prostoru na příkladu Lennonovy zdi v Praze (V perspektivě distribuce moci, destrukce a komunikace) / Controversy of visual image in public space on an example of Lennon's Wall in Prague (From the perspective of power distribution, destruction and communication)

Kotrlá, Jitka January 2019 (has links)
The following diploma thesis deals with image destruction in the public space, specifically focuses on its selected fragments, which can be considered as communication messages. The work provides a synchronous and diachronic analysis of the subject of the research as well as the transformation of its statuses, thus concentrating on the acquisition, transformation and extinction of the symbolic meanings of the object within the cultural- historical complex. The pattern of destruction of the image in the public space is chosen as Lennon's Wall in Prague, whose constant visual and meaningful transformation is taking place today - against the backdrop of the historical, power and cultural context. The theoretical basis is based on the analysis of change based on the concept of "discourse" and "discourse formation" by Michel Foucault, as well as on the anchoring of methodology in CDA Norman Fairclough and DHA Ruth Wodak. Keywords Visual Image in Public Space, Lennon's Wall, Linking, Discourse, Destruction, Communication, Power.
323

Rheological and Mechanical behaviour of Block copolymers, Multigraft copolymers and Block copolymer Nanocomposites

Thunga, Mahendra 18 June 2009 (has links)
Block copolymers are commercially significant and fundamentally interesting class of polymeric materials. The ability to undergo interfacial thermodynamics-controlled microphase separation from a completely disordered state in the melt to a specifically defined ordered structure through self-organization makes the block copolymers based materials unique. Block copolymer are strongly replacing many of the commercially available polymers due to their unique microstructure and properties. The most practical interests of block copolymers lie in the area of thermoplastic elastomers (TPEs). The objective of the present thesis work is to developing novel roots for enhancing the physical and mechanical properties in block copolymer and multigraft copolymers. Initially the properties are tailored by controlling chemical architecture at synthesis level and by selective blending at production level. This gives an easy access for improvement of the material properties and this is one of my major tasks in the present research modules. Further the block copolymer based TPEs are cross-linked in presence of electron beam (EB) radiation for developing materials with superior properties. The electron beam radiation has the ability to alter material parameters at molecular level for enhancing the macroscopic properties. The desirable physical and chemical properties can be easily attained by varying the radiation beam parameters. In addition to that, controlling the material at nanometer scale is one of the greatest challenges for current nanocomposite research. In elastomeric materials it is very prominent to fill the rubber matrix with nano particles from carbon or silica by melt mixing technique for enhancing the material properties. Other than conventional melt mixing technique, sol–gel processing is also a versatile technique, which making it possible to produce a wide variety of materials and to provide existing materials with novel properties. A combination of in situ sol-gel reaction with electron beam cross-linking in TPEs from triblock copolymer has been demonstrated for the first time as one of the novel nanocomposite system in this work. The main advantage of this system lies in controlling the material behaviour by finely tuning the size of silica nano particle generated inside TPE during in situ sol-gel reaction. Finally, the various roots employed for enhancing the material behaviour in block copolymers in the above research module were secussfully employed on super elastic multigraft copolymers for improving their strength withour sacrificing the super elastic nature.
324

Retinal Pigment Epithelium Cell Alignment on Nanostructured Collagen Matrices

Ulbrich, Stefan, Friedrichs, Jens, Valtink, Monika, Murovski, Simo, Franz, Clemens M., Müller, Daniel J., Funk, Richard H. W., Engelmann, Katrin January 2011 (has links)
We investigated attachment and migration of human retinal pigment epithelial cells (primary, SV40-transfected and ARPE-19) on nanoscopically defined, two-dimensional matrices composed of parallel-aligned collagen type I fibrils. These matrices were used non-cross-linked (native) or after riboflavin/UV-A cross-linking to study cell attachment and migration by time-lapse video microscopy. Expression of collagen type I and IV, MMP-2 and of the collagen-binding integrin subunit α2 were examined by immunofluorescence and Western blotting. SV40-RPE cells quickly attached to the nanostructured collagen matrices and aligned along the collagen fibrils. However, they disrupted both native and cross-linked collagen matrices within 5 h. Primary RPE cells aligned more slowly without destroying either native or cross-linked substrates. Compared to primary RPE cells, ARPE-19 cells showed reduced alignment but partially disrupted the matrices within 20 h after seeding. Expression of the collagen type I-binding integrin subunit α2 was highest in SV40-RPE cells, lower in primary RPE cells and almost undetectable in ARPE-19 cells. Thus, integrin α2 expression levels directly correlated with the degree of cell alignment in all examined RPE cell types. Specific integrin subunit α2-mediated matrix binding was verified by preincubation with an α2-function-blocking antibody, which impaired cell adhesion and alignment to varying degrees in primary and SV40-RPE cells. Since native matrices supported extended and directed primary RPE cell growth, optimizing the matrix production procedure may in the future yield nanostructured collagen matrices serving as transferable cell sheet carriers. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
325

Výzkum vzájemné interakce membránových receptorů NKR-P1D a Clrb / Studies on interactions between NKR-P1D and Clrb membrane receptors

Hanč, Pavel January 2011 (has links)
Studies on interactions between NKR-P1D and Clrb membrane receptors Interaction between murine NKR-P1D and Clrb receptors was originally described as a novel type of "MHC class-I independent missing-self recognition" and was shown to confer protection from killing by natural killer cells.[1] However, further study brought conflicting results suggesting that NKR-P1D does not binds Clrb strongly if it does at all.[2] In order to address the issues arising from these conflicting results, we have recombinantly expressed the extracellular domains of both receptors in E. coli cells and refolded the proteins in vitro. The quality of refolding was confirmed both by determining the disulphide bonding pattern using FTMS and measuring 1 H/15 N-HSQC spectra. By means of size exclusion chromatography and analytical ultracentrifuge we were unable to provide convincing results for the interaction itself. However, using SPR technique, a weak, specific, pH-dependent interaction was observed. Interaction between the proteins in solution was immobilized using chemical cross-linking technique. Three cross-linking reagents, EDC, DSG and DSS were used. The reaction mixture was separated by means of SDS-PAGE and protein bands corresponding to dimers were digested in gel. Using FT-MS we were able to find peptides from both...
326

Vazba eIF3 v komplexu s eIF5 a eIF1 na ribosomální podjednotku 40S je doprovázena dramatickými strukturními změnami / Binding of eIF3 in complex with eIF5 and eIF1 to the 40S ribosomal subunit is accompanied by dramatic structural changes

Zeman, Jakub January 2019 (has links)
In eukaryotic translation, eukaryotic initiation factors (eIFs) are at least as important as the ribosome itself. Some of these factors play different roles throughout the entire process to ensure proper assembly of the preinitiation complex on mRNA, accurate selection of the initiation codon, errorless production of the encoded polypeptide and its proper termination. Perhaps, the most important factor integrating signals from others and coordinating their functions on the ribosome is eIF3. In Saccharomyces cerevisiae, eIF3 is formed by five subunits. All these subunits contain structural motifs responsible for contact with ribosomal proteins and RNAs. In addition to these highly structured parts, the rest of eIF3 is unstructured and very flexible. Therefore, despite the recent progress thanks to the use of a cryo-electron microscopy, a precise structure and position of eIF3 on the 40S ribosomal subunit are still not known. Also, the presence of eIF3 on 80S during early elongation and its role in reinitiation and readthrough are not fully understood. In order to crack mysteries of yeast eIF3, we used x-ray crystallography, chemical cross- linking coupled to mass spectrometry, and various biochemical and genetic assays. We demonstrated that eIF3 is very compactly packed when free in solution. This...
327

Kooperationsprojekt

Ebermann, Dana, Schmied, Josef 05 December 2019 (has links)
Der interuniversitäre Bachelor-Studiengang Energy Efficiency and Englishes hat die Zielsetzung, dass Studierende zum einen ingenieurs- und technikwissenschaftliche Kompetenzen und zum anderen kultur- und sprachwissenschaftliche Kompetenzen erwerben und somit für den Arbeitsmarkt bessere Voraussetzungen mitbringen. Ziel des Ko- Pi-Projektes war es, die Module „Einführung Energietechnik“ und „Applied Linguistics“ besser an die Bedürfnisse der Studierenden anzupassen und gleichzeitig die Verknüpfung von technikwissenschaftlichen mit sprachwissenschaftlichen Kompetenzen zu schaffen, um diese praktisch im Unterricht anzuwenden und weiterzuentwickeln.
328

Effects of Different Display Form Factors on InfoVis Applications: Exploring Selection Management and Brushing and Linking for Mobile Cross-Device Interaction

Flemisch, Tamara 16 June 2020 (has links)
Diese Arbeit untersucht wie man mit mehreren, miteinander koordinierten Mobilgeräten Selektionen verwalten und Brushing und Linking unterstützen kann. Im Rahmen der Arbeit wird ein konzeptionelles Framework zur Selektionsverwaltung für mehrere Geräte angedacht und ein Konzept zur Selektionsverwaltung vorstellt, das Brushing und Linking für Mobilgeräte unterstützt. Des Weiteren werden Ziele für den Prototypen erörtert, die zur Umsetzung das Konzept beitragen. Mobile Geräte werden immer häufiger für Informationsvisualisierungen verwendet. Jedoch wurde bisher noch nicht untersucht, wie gängige Interaktionstechniken, wie Brushing und Linking, für diese Geräte anpassen werden müssen. Während des Brushings, werden zusätzlich Selektionen erstellt, für die es bislang keine Art der Verwaltung für Mobilgeräte gibt. In dieser Arbeit wird untersucht wie man Brushing und Linking mit mehreren Mobilgeräten unterstützen kann und Selektionen gleichzeitig verwalten kann.:1 Introduction 1.1 Contributions 1.2 Motivation and Background 1.3 Goals 1.4 Research Questions 1.5 Thesis Overview 2. Related Work 2.1 Mobile Devices for InfoVis and Their Screen Real Estate Issues 2.2 Interacting with CMVs 2.3 Brushing and Linking 2.4 Summary 3 Selection Management and Brushing and Linking for Mobile Cross- Device Interaction 3.1 The Selection Management Framework 3.2 Fundamental Information About VisTiles 3.3 Design Considerations 3.4 Creating Selections Within a Visualization 3.5 Interacting with Selections Within a Visualization 3.6 Managing Multiple Selections 3.7 Managing a Single Selection 3.8 Linking Selections to Other Devices 3.9 Incorporating Join Operations 3.10 Overview over Side-by-side Interactions 3.11 Summary: Reviewing the Selection Management Framework 4 Prototype 4.1 Technical Setup 4.2 Techniques 5 Conclusion and Discussion 5.1 Discussion 5.2 Future Work 5.3 Conclusion / This thesis examines how to manage selections and use brushing and linking with multiple coordinated mobile devices. We discuss thoughts for a conceptual framework for selection management in multi-device environments. We then present a concept for managing selections and supporting brushing and linking for co-located mobile devices. Finally, we are providing an overview of and the goals for our proof-of-concept prototype. More and more mobile devices are used for visualization. However, it is still an open question how to adjust common interaction techniques, such as brushing and linking, for mobile devices. Furthermore, it has not been addressed how to manage the selections that are created through brushing. We explore how brushing and linking can be used in a setting with multiple, co-located mobile devices and how to manage its selections.:1 Introduction 1.1 Contributions 1.2 Motivation and Background 1.3 Goals 1.4 Research Questions 1.5 Thesis Overview 2. Related Work 2.1 Mobile Devices for InfoVis and Their Screen Real Estate Issues 2.2 Interacting with CMVs 2.3 Brushing and Linking 2.4 Summary 3 Selection Management and Brushing and Linking for Mobile Cross- Device Interaction 3.1 The Selection Management Framework 3.2 Fundamental Information About VisTiles 3.3 Design Considerations 3.4 Creating Selections Within a Visualization 3.5 Interacting with Selections Within a Visualization 3.6 Managing Multiple Selections 3.7 Managing a Single Selection 3.8 Linking Selections to Other Devices 3.9 Incorporating Join Operations 3.10 Overview over Side-by-side Interactions 3.11 Summary: Reviewing the Selection Management Framework 4 Prototype 4.1 Technical Setup 4.2 Techniques 5 Conclusion and Discussion 5.1 Discussion 5.2 Future Work 5.3 Conclusion
329

A study of chymotrypsin immobilization conditions for improved peptide mapping

Elshalale, Fatma 03 1900 (has links)
No description available.
330

Development of Inhibitors of Amyloid Fibril Propagation / Développement d'inhibiteurs de la propagation des fibres amyloïdes

Bendifallah, Maya 16 December 2019 (has links)
L'α-Synuclein (αSyn) fibrillaire, impliqué dans la maladie de Parkinson et d’autres synucleinopathies, peut se propager entre cellules de manière « prion-like » et cette propagation est liée à la progression de la maladie. Durant cette étude, nous nous sommes tournés vers les chaperons moléculaires impliqués dans l’agrégation de l’αSyn ou bien dans sa toxicité afin de trouver des candidats capables d’interférer avec la propagation. Nous avons ensuite testé l’effet des chaperons capables de se lier aux fibres d’αSyn sur l’internalisation des fibres d’αSyn par les cellules Neuro-2a. Nous démontrons que l’interaction avec l’αSyn agrégeant avec αB-crystallin (αBc) ou Carboxyl terminus of Hsc70-interacting protein (CHIP) a mené à la formation de fibres qui sont moins internalisées par les cellules. Enfin, en passant par une stratégie de pontage chimique optimisé couplé à la spectrométrie de masse, nous avons identifié les zones d’interaction entre l’αSyn fibrillaire et soit αBc, soit CHIP. Ces résidus issus des chaperons, se trouvant à proximité des fibres d’αSyn dans les complexes, pourraient être développés dans des mini-chaperons peptidiques, capables d’enrober la surface des fibres et ainsi de bloquer la liaison à la membrane et l’internalisation des fibres. De surcroît, des polypeptides issus des partenaires précédemment identifiés d’αSyn ont été testé pour leur liaison aux fibres et leur effet sur la propagation des fibres. / Fibrillar α-Synuclein (αSyn) is the molecular hallmark of Parkinson’s Disease and other synucleinopathies. Its prion-like propagation between cells is linked to disease progression. In this study, we looked to molecular chaperones previously implicated in αSyn fibrillation and/or toxicity to identify proteins capable of binding αSyn fibrillar aggregates in order to target their propagation. We further assessed the effect of the fibril-binding chaperones on internalization of αSyn fibrils by Neuro-2a cells. We demonstrate that the interaction of aggregating αSyn with αB-crystallin (αBc) or Carboxyl terminus of Hsc70-interacting protein (CHIP) led to the formation of fibrils that are less internalized by cells. Finally, using an optimized chemical cross-linking and mass spectrometry strategy, we identified the interaction areas between fibrillar αSyn and either αBc or CHIP. These chaperone residues, located proximally to αSyn fibrils, could be subsequently developed into peptidic mini chaperones, capable of coating the fibril surface and thereby blocking fibrillar cell binding and internalization. Furthermore, polypeptides derived from previously identified αSyn binding partners were tested for their binding to αSyn fibrils and subsequent effect on fibril propagation.

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