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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

On the molecular basis of α-synuclein aggregation on phospholipid membranes in the presence and absence of anle138b / Zur molekularen Basis der α-Synuclein Aggregation an Phospholipid Membranen in der Gegenwart und Abwesenheit von anle138b

Antonschmidt, Leif 27 November 2021 (has links)
No description available.
62

THE ROLE OF PROTEIN AS A FOAM BOOSTER IN THE PRESENCE OF OIL

Coffin, Jared M. 30 July 2019 (has links)
No description available.
63

Preparation, Functionalization, and/or Characterization by X-ray Photoelectron Spectroscopy of Carbon Surfaces for Biosensors and Other Materials

Jain, Varun 01 August 2019 (has links)
My dissertation is primarily divided into two parts. The first deals with the preparation, functionalization, and characterization of carbon surfaces prepared by direct current magnetron sputtering (DCMS) and high power impulse magnetron sputtering (HiPIMS) as substrates for bioarrays. Part two discusses applications of XPS peak fitting in surface chemical analysis. Chapter 1, the introduction, includes (i) a discussion of the construction of bioarrays and the preparation of sputtered surfaces, e.g., by DCMS and HiPIMS, and also functionalization (bioconjugate) chemistry with special emphasis on the importance of covalent functionalization of surfaces, and (ii) a discussion of the surface characterization techniques and accompanying analysis methods I have primarily used, which include X-ray photoelectron spectroscopy (XPS), near-ambient pressure XPS (NAP-XPS), XPS peak fitting, and contact angle goniometry (wetting). Chapter 2 discusses the preparation, characterization, and functionalization of DCMS and HiPIMS carbon surfaces for bioarrays. Here, two functionalization chemistries are explored, where the activity of DCMS and HiPIMS carbon towards amidation and amination is compared. Chapter 3 focuses on the use of Gaussian-Lorentzian sum (GLS) and Gaussian-Lorentzian product (GLP) line shapes in the context of peak fitting XPS narrow scans. This discussion includes a comparison of the GLS and GLP line shapes with the Voigt function. Chapters 4 and 5 discuss the applications of XPS peak fitting in materials characterization. Chapter 4 talks about XPS data analysis in the context of the chemical vapor deposition of various aminosilanes and their effect on peptide stability and purity. Chapters 5 describes the surface chemical analysis of various materials by NAP-XPS, including accompanying data analysis and/or peak fitting. The materials probed here cannot be analyzed at ultra-high vacuum by conventional XPS, hence, they are analyzed by NAP-XPS. Chapter 5 is divided into 5 sections. Section 5.1.1 discusses the characterization and analysis of a solution of bovine serum albumin (BSA) by peak fitting the C 1s and O 1s peak envelopes. Section 5.1.2 discusses the analysis of polytetrafluoroethylene (PTFE) at different pressures. Here, the effect of increasing background pressure and X-ray illumination time on the equivalent widths of the F 1s narrows scans is shown. Environmental charge compensation is also discussed here. Section 5.1.3 includes the analysis of poly(γ-benzyl L-glutamate) (PBLG), where the C 1s and O 1s peak envelopes were peak fitted to determine/confirm the structure and composition of this polymer. Section 5.1.4 contains an analysis and comparison of three different human hair samples: (i) untreated, (ii) colored, and (iii) bleached. Here, a comparison of the Si 2p, S 2p, and C 1s peaks illustrates the effects of the different treatments. Section 5.1.5 shows the characterization and analysis of liquid and solid phosphate buffered saline (PBS). Chapter 6 presents conclusion of my work and discusses future work.
64

Synthesis and Characterization of Novel Flavonoid-Based Fluorescent Sensors and other Sensors with Excited State Intramolecular Proton Transfer for Biological Applications

McDonald, Lucas J. 23 May 2018 (has links)
No description available.
65

Mechanistic approaches towards understanding particle formation in biopharmaceutical formations : the role of sufactant type and level on protein conformational stability, as assessed by calorimetry, and on protein size stability as assessed by dynamic light scattering, micro flow imaging and HIAC

Vaidilaite-Pretorius, Agita January 2013 (has links)
Control and analysis of protein aggregation is an increasing challenge to biopharmaceutical research and development. Therefore it is important to understand the interactions, causes and analysis of particles in order to control protein aggregation to enable successful biopharmaceutical formulations. This work investigates the role of different non-ionic surfactants on protein conformational stability, as assessed by HSDSC, and on protein size stability as assessed by Dynamic Light Scattering (DLS), HIAC and MFI. BSA and IgG2 were used as model proteins. Thermal unfolding experiments indicated a very weak surfactant-immunoglobulin IgG2 interaction, compared to much stronger interactions for the BSA surfactant systems. The DLS results showed that BSA and IgG2 with different surfactants and concentration produced different levels of particle size growth. The heat treatment and aging of samples in the presence of Tween 20, Tween 80, Brij 35 and Pluronic F-68 surfactants led to an increase in the populations of larger particles for BSA samples, whereas IgG2 systems did not notably aggregate under storage conditions MFI was shown to be more sensitive than HIAC technique for measuring sub-visible particles in protein surfactant systems. Heat treatment and storage stress showed a significant effect on BSA and IgG2 protein sub-visible particle size stability. This work has demonstrated that both proteins with different Tween 20, Tween 80, Brij 35 and Pluronic F-68 concentrations, have different level of conformational and size stability. Also aging samples and heating stress bears the potential to generate particles, but this depends on surfactant type. Poor predictive correlations between the analytical methods were determined.
66

PR 2.0 - The New PR : A case study on the use of PR by pirates and anti-pirates. / PR 2.0 - The New PR : An explorative case study on the use of PR by pirates and anti-pirates.

Stypulkowski, David January 2009 (has links)
<p>Recent development of the internet encompasses elements such as social networks, blogs and wikis. With the help of these elements, popularly gathered under the umbrella term web 2.0, the pirates supporting file sharing have made the file sharing debate a national concern in Sweden.</p><p>This thesis studies the pirates’ and anti-pirates’ use of PR by qualitative case studies of organizations representing the two different sides in the debate. The use of PR by the different organizations is compared, the differences and similarities are considered and characteristics of the new PR are brought to attention.</p><p>The study finds that PR is taking a new direction and that these new ways to use PR are important to achieve success in influencing opinion. The two sides use PR in very different ways where the anti-pirates use more traditional ways of PR while the pirates make use of new PR methods virtually exclusively.</p>
67

PR 2.0 - The New PR : A case study on the use of PR by pirates and anti-pirates. / PR 2.0 - The New PR : An explorative case study on the use of PR by pirates and anti-pirates.

Stypulkowski, David January 2009 (has links)
Recent development of the internet encompasses elements such as social networks, blogs and wikis. With the help of these elements, popularly gathered under the umbrella term web 2.0, the pirates supporting file sharing have made the file sharing debate a national concern in Sweden. This thesis studies the pirates’ and anti-pirates’ use of PR by qualitative case studies of organizations representing the two different sides in the debate. The use of PR by the different organizations is compared, the differences and similarities are considered and characteristics of the new PR are brought to attention. The study finds that PR is taking a new direction and that these new ways to use PR are important to achieve success in influencing opinion. The two sides use PR in very different ways where the anti-pirates use more traditional ways of PR while the pirates make use of new PR methods virtually exclusively.
68

Photoacoustic drug delivery using carbon nanoparticles activated by femtosecond and nanosecond laser pulses

Chakravarty, Prerona 09 January 2009 (has links)
Cellular internalization of large therapeutic agents such as proteins or nucleic acids is a challenging task because of the presence of the plasma membrane. One strategy to facilitate intracellular drug uptake is to induce transient pores in the cell membrane through physical delivery strategies. Physical approaches are attractive as they offer more generic applicability compared with viral or biochemical counterparts. Pulsed laser light can induce the endothermic carbon-steam reaction in carbon-nanoparticle suspensions to produce explosive photoacoustic effects in the surrounding medium. In this study, for the first time, these photoacoustic forces were used to transiently permeabilize the cell membrane to deliver macromolecules into cells. Intracellular delivery using this method was demonstrated in multiple cell types for uptake of small molecules, proteins and DNA. At optimized conditions, uptake was seen in up to 50% of cells with nearly 100% viability and in 90% of cells with ≥90% viability, which compared favorably with other physical methods of drug delivery. Cellular bioeffects were shown to be a consequence of laser-carbon interaction and correlated with properties of the carbon and laser, such as carbon concentration and size, laser pulse duration, wavelength, intensity and exposure time. Similar results were observed using two different lasers, a femtosecond Ti: Sapphire laser and a nanosecond Nd: YAG laser. Uptake was also shown in murine skeletal muscles in vivo with up to 40% efficiency compared to non-irradiated controls. This synergistic use of nanotechnology with advanced laser technology could provide an alternative to viral and chemical-based drug and gene delivery.
69

Problematika stárnutí asfaltových pojiv a směsí / Ageing of asphalt binders and mixtures

Štěpanovský, Vlastimil January 2015 (has links)
Diploma thesis is particularly focused on ageing of asphalt mixtures and asphalt binders. In the theoretical part an array of methods simulating short term and long term ageing consequently is introduced. The main objective of the practical part was to carry out the long-term ageing test method BSA (Braunschweiger Alterung). Thereafter, specimens testing for stiffness properties according to CSN EN 12697-26 were made. After conducting the measurement on those, asphalt binder was extracted and processed to follow-up testing. The testing consisted of a range of methods – Penetration CSN EN 1426, Ring and Ball test CSN EN 1427, Determination of the Frass breaking point CSN EN 12593, Determination of complex shear modulus CSN EN 14770 and Dynamic viscosity using a dynamic shear rheometer (DSR). The given results were assessed in the last part in order to evaluate the rate of the binder degradation caused by the method BSA.
70

The Cancer Recognition (CARE) Antibody Test

Thornthwaite, Jerry T., McDuffee, Emily C., Harris, Robert B., Secor McVoy, Julie R., Lane, I. W. 28 December 2004 (has links)
The cancer recognition (CARE) antibody (Ab) test is a serologic assay for a specific IgM that is elevated in cancer patients. All tests are measured using an indirect enzyme-linked immunosorbent assay (ELISA) of human serum. The target polypeptide in the CARE Ab test is the IgM binding epitope (LT-11) of the CARE antigen (Ag) consisting of a 16 mer structure that has been produced synthetically. The mean relative concentration (MRC) is determined relative to standard, normalized human plasma. Non-parametric analysis showed median MRC values of healthy volunteers (HVs) with no history of cancer (n=47), family history of cancer (n=126) and a previous cancer history (n=24) to be 26, 34 and 46, respectively. It was determined that there was no significance found among the medians of the three HV groups (P=0.53). The specificity of the HV types was between 87 and 98%. Benign/non-cancer surgical patients (n=27) had a median value of 20 with a specificity of 96%. The cancer patients (n=61) had a median value of 246 with a sensitivity of 89%. There was a significant difference between the HV and cancer patients (P<0.0001) as well as between the benign/surgical non-cancerous group and cancer patients (P<0.0001). The IgM antibody is heat stable at room temperature for two days versus being frozen at -80°C (r2=0.97). Either serum or plasma samples may be used in the CARE Ab test (r2=0.92). The CARE Ab was almost exclusively IgM with no serum conversion to IgG in sequential measurements of patients with cancer over a six-month period. Preliminary data from patients undergoing post-operative cancer treatment showed that decreasing Ab levels revealed patients negative for residual cancer or undergoing remission, while relapsing patients show an increase in Ab levels. A return to a positive Ab level shortly after treatment is a poor prognostic sign while in advanced cancers the Ab levels may be depressed significantly.

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