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Myocardial fibrosis and pathological hypertrophy in the rat with aorta-constricted hypertension
No full textWe used the inter-renal abdominal aorta constriction model to induce hypertension and cardiac hypertrophy in rats within seven days after surgery. Rapid induction of hypertension resulted from the activation of the renin-angiotensin system (RAS) due to renal ischemia. Microscopically, marked interstitial fibrosis with focal necrosis and diffuse perivascular fibrosis in the myocardium were observed. Myocardial fibrosis appears before myocyte necrosis and its severity is proportional to the duration of established hypertension and the magnitude of blood pressure. To distinguish the humoral factors from mechanical factors, aorta-constricted hypertensive rats were treated with oral captopril or hydralazine. Captopril treatment prevented the development of hypertension, myocardial hypertrophy and fibrosis. Hydralazine treatment, although it reduced the blood pressure, did not prevent myocardial hypertrophy or fibrosis. This study reveals a potentially important clinical aspect of captopril, an angiotensin-converting enzyme (ACE) inhibitor which blocks the formation of angiotensin II (ANG II) from ANG I, which relates to the beneficial effects on myocardial hypertrophy and fibrosis (ventricular remodeling) in hypertension. However, ACE has other substrates in addition to ANG I, including kinins (which are potent vasodilators); thus, the mechanism of ACE's action may be more complex than mere blockade of ANG II formation. To further distinguish the relative role of hemodynamic and humoral factors in promoting myocardial fibrosis, we used osmotic minipumps to chronically infuse a subpressor dose of ANG II that induced a marked fibrotic response in the rat heart which was similar to the fibrotic lesions seen in the myocardium of aorta-constricted hypertensive rats. Since these cardiac lesions appear in both left and right ventricles, due to the in-series alignment, with respect to the systemic circulation of the ventricles, the occurrence of myocardial fibrosis and hypertrophy provides further evidence that ANG II may directly stimulate myocardial fibroblast proliferation and myocardiocyte hypertrophy through its trophic effect.Made available in DSpace on 2011-05-07T12:38:09Z (GMT). No. of bitstreams: 2
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Previous issue date: 1992Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding ([email protected]) on 2011-05-07T14:43:39Z
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Keyboard performance techniques required for music synthesizers
No full textThe problem of the study was to determine expert synthesists' perceptions of the process by which performance proficiency in the synthesizer can be developed.Analysis of the problem resulted in the formulation of the following subproblems: (1)What keyboard skills do expert synthesists consider important in the development of performance proficiency on the synthesizer? (2) How do expert synthesists perceive: (a) Their overall musical education; and (b) the process by which they developed their current level of performance proficiency? (3) What advice do expert synthesists have for students desiring to develop performance proficiency on the synthesizer?The investigator constructed a Likert scale questionnaire consisting of techniques required to perform on the synthesizer and submitted it to a panel of 15 experts. The investigator selected ten widely recognized expert synthesizer performers from the panel of experts and interviewed them regarding (a) their overall musical education, (b) their learning specific to acquiring expertise as synthesists, and (c) their advice for students desiring to develop performance proficiency on the synthesizer.The three techniques considered most important by the panel of experts were: (1) Dynamic control via attack velocity; (2) Pitch bend; (3)Continuous controller techniques: wheel, joystick, slider.The study also resulted in the following conclusions: (1) All the synthesists underwent formal musical training and played piano and/or organ prior to learning to play the synthesizer but were, however, self-taught regarding their performance skill on the synthesizer. (2) All the synthesists had the desire and ability to begin improvisation on keyboard and other instruments at an early age. Furthermore, they learned to perform in a variety of musical styles on their own. (3) The synthesists were unanimous in expressing that (a) the musical potential of the synthesizer is so impressive that the instrument should be included in music programs at all levels, and (b) colleges and universities should offer the synthesizer as a performance major. None of them could, however, identify a synthesizer teacher whom they could recommend.Made available in DSpace on 2011-05-07T13:14:23Z (GMT). No. of bitstreams: 2
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Previous issue date: 1994Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding ([email protected]) on 2011-05-07T14:52:08Z
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Synthesis and characterization of novel polymer-ceramic nanocomposites: Organoceramics
No full textThis manuscript describes the synthesis and characterization of novel polymer-ceramic nanocomposites (organoceramics) based on various water soluble polymers and calcium aluminate hydrates. Synthesis of these materials involves the aqueous precipitation of the inorganic crystals in the presence of polymer. The presence of polymer during crystallization often leads to changes in particle morphology, and in some cases intercalation.The organoceramics based on poly(vinyl alcohol) (PVA) and \rm CaO{\cdot} Al\sb2O\sb3{\cdot} 10H\sb2O (CAH\sb{10}) were found to exhibit retarded phase transformation kinetics and unique particle morphologies. Intercalation of PVA between layers of \rm\lbrack Ca\sb2Al(OH)\sb6\rbrack\sp+\lbrack(OH){\cdot} 3H\sb2O\rbrack\sp- occurred during crystal growth, resulting in an organoceramic containing up to 40% polymer by weight. Polymer intercalation resulted in an expression of the interlayer by approximately 10 A, consistent with the formation of a double layer of PVA chains across each interlayer. Thermal degradation of the inorganic and polymeric components of the organoceramic occurred at higher temperatures than the individual materials. Compressive strength of PVA organoceramic powder compacts was significantly higher than that of \rm\lbrack Ca\sb2Al(OH)\sb6\rbrack\sp+\lbrack(OH){\cdot} 3H\sb2O\rbrack\sp- compacts, possibly reflecting substantial differences in particle morphologies.Made available in DSpace on 2011-05-07T13:14:39Z (GMT). No. of bitstreams: 2
license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5)
9314917.pdf: 8578996 bytes, checksum: 7f0493656db2c2441cdfd4b44ee17765 (MD5)
Previous issue date: 1993Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding ([email protected]) on 2011-05-07T14:52:12Z
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Intermolecular interactions in supercritical fluid solutions from fluorescence spectroscopy
No full textMuch of the unusual behavior in supercritical fluids (SCF's), including enhanced solubilities, synergistic effects of mixed solutes, and entrainer effects, may be explained by a region around the solute that has a higher density than the bulk. We present a new technique to investigae SCF's using fluorescence spectroscopy to probe the local interactions. In contrast to thermodynamic measurements, this technique determines the strength of interactions on a molecular scale, which is important in the development of more accurate thermodynamic models. For pyrene, naphthalene, dibenzofuran and carbazole in SCF CO\sb2, C\sb2H\sb4 and CF\sb3H, the results indicate stronger solute/solvent interactions near the critical point and local densities that are liquid-like, even when the bulk density is quite low. We also present excimer fluorescence data that emphasize the importance of solute/solute interactions in dilute supercritical fluid solutions. Finally, results from exciplex fluorescence studies of a solute/SCF/entrainer system indicate a dramatic solvent effect on the photophysical kinetics.Made available in DSpace on 2011-05-07T14:27:00Z (GMT). No. of bitstreams: 2
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Previous issue date: 1989Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding ([email protected]) on 2011-05-07T15:06:50Z
Item is restricted indefinitely.Restriction data tranferred 2014-07-01T11:32:07-05:00
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Photoemission studies of surfaces and thin film systems of silver and gold
No full textAngle-integrated photoemission spectroscopy was used to study the properties
of Au 4f7; 2 core level in several systems: Au overlayers on Ag(lll),
Au overlayers on Ag(lOO), and an Au monolayer buried in Ag(lll). Properties
of a zone-center surface state were also investigated with the use of angle
resolved photoemission spectroscopy for many related systems: the clean
Ag(lll) surface, Ag overlayers on Au(lll), and Au overlayers on Ag(lll).
For Au epitaxial overlayers on Ag, the binding energies of Au 4f7; 2 core
level were measured as a function of overlayer thickness. The Au 4f 7/2 core
level associated with the top layer is shifted relative to the underlayers.
With increasing Au coverages on Ag(lOO) beyond 5 monolayers, the surface
reconstruction changes from (lXl) to (SX20), and the binding energies change
correspondingly. The measured binding energies are related to the variation
of the one-electron potential within the overlayer. For the Au monolayer
buried in Ag(lll), the Au 4f7/2 core-level binding energies were measured as
a function of the depth below the surface. The measured Au 4f7/2 binding
energy converges asymptotically to a constant value for depths greater than
about three atomic monolayers. The measured spatial range of the surface
effect is significantly greater than what is expected from a jellium calculation.
This result implies that significant subsurface-core-level shifts
can occur for close-packed metal surfaces. For the studies of the zone
center surface state of Au overlayers on Ag(lll), it was observed that this
surface state evolves continously from Ag(lll)-like to Au(lll)-like for
increasing Au coverages on Ag, and a similar behavior was also observed for
Ag on Au(lll). The shifts of the binding energies as a function of
overlayer thickness can be related to the z-dependence of the surface state
wave function. The envelope function of this surface state in Ag(lll) was
further determined by use of Ag(lll) samples with one subsurface atomic
layer substituted by a matched Au atomic layer. Using this technique, the
decay length of this surface state is determined to be about 28 A. The
photoemission cross section of the Ag(lll) surface state was also measured
over the photon energy range of 36 - 65 ev. A resonance at 54 eV was
observed. The energy position of this resonance is in agreement with the
prediction of a theoretical model based on an extension of the directtransition
model for bulk states.Submitted by Carolyn Mead ([email protected]) on 2011-06-02T14:47:18Z
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1987_hsieh.pdf: 6237247 bytes, checksum: ab106d81d572b9fc847d690314b4c1d5 (MD5)Made available in DSpace on 2011-06-02T14:47:18Z (GMT). No. of bitstreams: 1
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Previous issue date: 1987Restriction data tranferred 2014-07-01T11:11:34-05:00
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Item is restricted indefinitely.ThesisU of I Onl
Expression of single chain antibody-encoding genes in fission yeast and tobacco
No full textThe goal of this project was to explore the expression of genes encoding single chain antibodies (SCA) in eukaryotic cells. During the course of this research, a new PCR-based strategy was developed that significantly reduced the time required for SCA gene synthesis. Although initially developed for the synthesis of SCA genes from templates of known sequence, PCR primers have now been developed that have universal applicability for this strategy. It was established that murine codon bias did not preclude efficient expression of SCA genes in E. coli.Using a SCA that recognized the hapten fluorescein (SCA 4420), it was established that Schizosaccharomyces pombe was a viable SCA expression system. We demonstrated that SCA protein produced by S. pombe was capable of binding hapten in vitro by showing that incubation of the total cell lysate with fluorescein conjugated Sepharose resulted in the selective removal of the SCA protein. The issue of SCA function in vivo was addressed by analyzing transgenic fission yeast by flow cytometry. These analyses were inconclusive; although the SCA 4420 expressing strains displayed the predicted attenuation of fluorescence, so did strains expressing a SCA against glutamine synthetase.Tobacco transformed with the SCA 4420 encoding gene failed to express the SCA to detectable levels. This is in agreement with recent literature indicating that immunoglobulin or derivatives thereof are not expressed in the plant cell cytoplasm. Whether the impediment to plant cytoplasmic expression occurs at translation or thereafter remains to be determined.Made available in DSpace on 2011-05-07T14:10:08Z (GMT). No. of bitstreams: 2
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Previous issue date: 1992Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding ([email protected]) on 2011-05-07T15:03:42Z
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Extent of co-worker involvement with African-American supported employees
No full text"Cultural differences may influence the employment status of African-American supported employees and contribute to their difficulties in obtaining and maintaining employment. The purpose of this study was to fill a void in the research literature on supported employment by comparing African-American and European-American supported employees with respect to five types of co-worker involvement, salaries and attrition rates, and occupational categories and employment tenure. Specifically, analyses were conducted to determine which claims of co-worker involvement best distinguished between the two groups. Results revealed more claims of co-worker involvement for ""training"" African-American supported employees during the first six months of employment than European-Americans; further, African-American supported employees were younger and separated from employment at higher rates per month than European-American supported employees. The results strongly suggest a need to examine the factors that may contribute to greater levels of co-worker involvement with African-American supported employees. Specific areas include recognizing individual differences, developing strengths, matching skills to appropriate training and employment needs, self-analyzing multicultural employment environments, utilizing cultural brokers, and providing cross-cultural training."Made available in DSpace on 2011-05-07T13:26:23Z (GMT). No. of bitstreams: 2
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Previous issue date: 1996Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding ([email protected]) on 2011-05-07T14:54:46Z
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X-Ray Topographic Studies of Deformation in Niobium and Dilute Niobium-Hydrogen Alloys
No full textAn experimental study of the deformation at a notch under tensile loading and by hydride precipitation has been conducted with x-ray diffraction topography. Lang topography, asymmetric crystal topography (ACT) and synchrotron white beam topography (WBT) were applied in this study. Crystals suitable for transmission x-ray topography (i.e. dislocation densities below 10('6) cm('-2)) were grown by the strain-anneal technique from ribbons of polycrystalline niobium of thickness less than 0.2 mm.A technique, also applicable to crystals in which the dislocation density is too high to allow the resolution of individual defects, is developed whereby the strain tensor about an arbitrary strain center may be determined from the relationship between the incremental rotation of the specimen and the resulting equi-inclination contour spacing. The analysis is used to estimate some of the strain tensor components about a precipitate of (beta)-NbH in a niobium crystal from measurements taken with characteristic x-radiation. Application of the analysis to synchrotron topography is also discussed.The generation of plasticity at a notch was studied in situ with ACT and WBT. Specimens of niobium were tested mainly at ambient temperatures although one specimen was tested at 158 K; only one specimen was a hydrogen alloy and it contained 1.8 atomic percent hydrogen. The crystals were deformed, and the resulting slip was found to agree with earlier studies.Made available in DSpace on 2014-12-16T20:51:52Z (GMT). No. of bitstreams: 1
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Previous issue date: 1983Embargo set by: Seth Robbins for item 71968
Lift date: Forever
Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDsRestricted to the U of I community idenfinitely during batch ingest of legacy ETDsU of I Only307 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1983
Development of EPR Methods for Simultaneous Measurements of Intra- and Extra-Cellular Oxygen Concentration in Vitro
No full textIn this thesis, the electron paramagnetic resonance (EPR) methods for simultaneous measurement of intra- and extracellular concentration of oxygen ( (O\sb2)) in viable cells have been developed.In the presence of Fe(CN)\sb6\sp{-3} in the medium, intracellular (O\sb2) is measured by a neutral \sp N-nitroxide and extracellular (O\sb2) is measured by a negatively charged \sp N, since charged species do not enter cells and the EPR spectrum of a \sp N-nitroxide does not overlap with that of a \sp N-nitroxide. The method is based in part on the minimal broadening of negatively charged nitroxides by Fe(CN)\sb6\sp{-3} and the very effective broadening of neutral nitroxides by the same paramagnetic ions. Results with this method confirm the existence of gradients in (O\sb2) between the extracellular and intracellular compartment in CHO cells and M5076 tumor cells, even without stimulation of cellular resiration by carbonyl cyanide m-chlorophenylhydrazone (CCCP). The nature of the barrier that needs to be involved to account for the experimental results raises some significant questions.Due to the potential toxic effect of Fe(CN)\sb6\sp{-3} to cells after long time exposure and the difficulties to extend the measurement of intracellular (O\sb2) to in vivo in the presence of Fe(CN)\sb6\sp{-3}, a new method without the use of Fe(CN)\sb6\sp{-3} was also studied. The study has been focused on the feasibility of developing nitroxides that localize selectively in the intracellular compartment so that the intracellular (O\sb2) could be measured without the use of Fe(CN)\sb6\sp{-3} and extracellular (O\sb2) could be measured simultaneously by a charged \sp N-nitroxide. It is based on the use of readily hydrolysed ester linkages, such that the nitroxides become converted intracellularly to ionic derivatives that do not cross cell membranes readily. Up to 120-fold increased concentrations of intracellular nitroxides and their one electron reduction product, the hydroxylamines, were obtained. The EPR spectra of the intracellular nitroxides and their partitions into water and CHCl\sb3 were consistent with their conversion to the ionic species. Further studies indicate that these nitroxides have the properties needed for their use as probes of intracellular (O\sb2) and that it should be feasible to synthesize nitroxides that will be even more effective for this purpose.Made available in DSpace on 2014-12-17T22:22:51Z (GMT). No. of bitstreams: 1
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Previous issue date: 1993Embargo set by: Seth Robbins for item 72575
Lift date: Forever
Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDsRestricted to the U of I community idenfinitely during batch ingest of legacy ETDsU of I Only129 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1993
High-resolution NMR spectroscopic analysis of anticancer drugs, DNA and their interactions: 1. Platinum anticancer compounds - DNA interactions. 2. Anthracycline drugs - DNA interactions and modified DNA
No full textChemotherapy with anticancer drugs is one of the main method of cancer treatment. The exploitation of the stereochemical interactions between anticancer drugs and DNA is of great importance for the ultimate clinical advances of cancer chemotherapy, which needs the detailed structural knowledge of DNA, drugs, and their interactions. Cisplatin is one of the most effecient and widely used anticancer drugs in the world. Extensive effort has been devoted to designing the new better anticancer platinum compounds. The structural studies on interactions of two anticancer platinum compounds, cisplatin and the third-generation bisplatinum compound 1,1/t,t, with DNA are described in this thesis. The structure of an intrastrand cisplatin-crosslinked didentate DNA duplex consisting of d(CCTG\rm\sp*G\sp*TCC) and its complement d(GGACCAGG) is determined by NMR spectroscopy. The refined duplex is unwound (\sim{-}21\sp\circ) and kinked ({\sim}58\sp\circ) toward the major groove at the \rm G\sp*G\sp* site and the minor groove is significantly widened. The stability of the major intrastrand cisplatin-G\rm\sp*pG\sp* adduct has been studied and this intrastrand cisplatin-crosslinked adduct appears to be converted into an interstrand crosslink adduct. Three palindromic DNA oligonucleotides, each having a single intrastrand cisplatin crosslinked at GpG site, have also been studied by NMR spectroscopy. The structural consequence of the incorporation of the \rm G\sp*G\sp* lesions into palindromic sequences is dependent on the location of the lesion sites in the sequence. Such alternative structural distortions may be relevant in understanding the protein recognition of the cisplatin-induced lesions. A new anticancer bisplatinum compound 1,1/t,t exhibits excellent cytotoxicity towards cisplatin-resistant cancer cells. The structure of the interstrand adduct of 1,1/t,t with a palindromic DNA oligomer CATGCATG has been determined by NMR spectroscopy. Upon platination by 1,1/t,t, the DNA octamer forms a novel hairpin structure with the platinated G\sb4 residue adopting a syn conformation and with the guanine base in the minor groove. Two such hairpins stack end-over-end and are linked together by the butanediamine tether to form a dumbbell structure. Such unusual structural distortion induced by the bisplatinum compound is completely different from that of the anticancer drug cisplatin-DNA adduct and may provide clues to explain the distinct biological activities of the two compounds.Anthracycline antibiotics are important anticancer intercalative drugs. The solution structures of anticancer anthracycline drugs aclacinomycin A and B, nogalamycin and disnogalamycin, complexed to a DNA hexamer have all been determined by high resolution NMR spectroscopy. Structural modification of DNA through covalent interactions have significant functional consequences and/or anticancer activities. Structural analysis of the C\sp2-methyl-hypoxanthine:Cytosine base pair and O\sp6-ethyl-Guanine:Cytosine base pair in B-DNA help understand their biological functions.Made available in DSpace on 2011-05-07T13:35:10Z (GMT). No. of bitstreams: 2
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Previous issue date: 1996Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding ([email protected]) on 2011-05-07T14:56:37Z
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