• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 128
  • 22
  • 4
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 178
  • 178
  • 178
  • 26
  • 21
  • 21
  • 16
  • 15
  • 12
  • 12
  • 10
  • 10
  • 9
  • 9
  • 9
  • 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.
131

Protective Mechanisms of Granulocyte-Colony Stimulating Factor Against Experimental Models of Stroke

Unknown Date (has links)
Ischemic stroke has a multiplicity of pathophysiological mechanisms. Granulocyte-colony stimulating factor (G-CSF) is an endogenous growth factor that exerts a diverse range of neuroprotection against ischemic stroke. Several lines of evidence demonstrated the contribution of endoplasmic reticulum (ER) in apoptotic cell death involving ischemia. Cell culture of undifferentiated PC12 cells were subjected to 10mM glutamate and selected doses of G-CSF (25ng/ml, 50ng/ml, 100ng/ml and 250ng/ml) for 24 hours. Cell viability, expression of the G-CSF receptor and expression level of CHOP were assessed in vitro. Sprague-Dawley rats were subjected to middle cerebral artery occlusion (MCAO). Rats were subcutaneously injected with G-CSF (n= 15; 50ug/kg body weight) 24 hours post-MCAO for 4 days. Vehicle treated rats were administered 5% dextrose for 1 day (n=4) or 4 days (n=16). Sham-operated rats (n=9) were not subjected to MCAO. Neurological deficit and infarct volume were measured while expression levels of pAKT, Bcl2, Bax, Bak, cleaved caspase-3, GRP78, ATF4, ATF6, p-p38MAPK, pJNK, CHOP and HSP27 were analyzed by western blotting. In vitro G-CSF receptor was expressed on undifferentiated PC12 cell, and an optimal dose of 50 ng/ml G-CSF significantly protected these cells against glutamate-induced cytotoxicity (P < 0.05). G-CSF significantly down-regulated (P < 0.01) the ER stressinduced pro-apoptotic marker CHOP in vitro. In vivo, G-CSF reduced infarct volume to 50% while significantly improved neurological deficit compared to vehicle rats. G-CSF significantly (P < 0.05) up-regulated pro-survival proteins pAKT and Bcl2 while downregulating pro-apoptotic proteins Bax, Bak and cleaved caspase 3 in the ischemic brain. It also significantly (P < 0.05) downregulated the ER intraluminal stress sensor GRP78, proteins of ER stress induced intracellular pathway; ATF4, ATF6, p-p38MAPK, pJNK and the ER stress induced apoptotic marker CHOP, which suggests that ER stress is being ameliorated by G-CSF treatment. G-CSF also reduced the level of HSP27, providing additional evidence of cellular stress reduction. G-CSF treatment increased cell survival by attenuating both general pro-apoptotic proteins and specific effector proteins in the ER stress induced apoptotic pathways. Our data has provided new insight into the anti-apoptotic mechanism of G-CSF, especially as it relates to ER stress induced apoptosis in ischemia. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2016. / FAU Electronic Theses and Dissertations Collection
132

Methionine sulfoxide reductases: studies on the reducing requirements and role in the metabolism of sulindac

January 1900 (has links)
The methionine sulfoxide reductase (Msr) enzymes catalyze the reduction of methionine sulfoxide (Met(O)) to methionine. The Msr enzymes protect cells against oxidative stress and may have a role in aging. The MsrA family of enzymes reduces stereospecifically the S epimer of free and protein-bound Met(O) while the MsrB family reduces the R epimer of Met(O) in proteins. It has been generally accepted, primarily from studies on MsrA, that the biological reductant for the Msr enzymes is thioredoxin (Trx), although high levels of dithiothreitol (DTT) can be used as the reductant in vitro. In contrast, certain MsrB enzymes show less than 10% of the activity with Trx as compared to DTT. This raises the possibility that in animal cells Trx may not be the direct hydrogen donor for the MsrB enzymes. Studies with bovine liver extracts have shown that thionein, the apoprotein of metallothionein, can function as a reductant for the Msr proteins. Certain selenium compounds such as selenocystamine and selenocystine can also serve as potent reducing agents for the Msr enzymes. Since an increased activity of Msr enzymes can reduce the level of oxidative damage in tissues, compounds that could activate Msr may have therapeutic potential. A high-throughput screening assay has been developed to screen large chemical libraries to find activators of MsrA, as well as specific inhibitors that could be useful research tools. This study will be done in collaboration with The Scripps Florida Research Institute. Sulindac was originally developed as a non-steroidal anti-inflammatory drug but has also shown efficacy in the treatment of certain cancers. The S epimer of sulindac is known to be reduced by MsrA, but the enzymes responsible for reduction of the R epimer are not known. / An activity has been purified from rat liver which is capable of reducing the R epimers of sulindac, free Met(O) and a dabsylated Met(O) substrate, the latter suggesting that this enzyme may have properties similar t o the MsrB enzymes. The oxidation of the epimers of sulindac to sulindac sulfone has also been characterized, and the members of the cytochrome P450 family involved in the oxidation have been identified. / by David J. Brunell. / Thesis (Ph.D.)--Florida Atlantic University, 2009. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2009. Mode of access: World Wide Web.
133

Electron Transfer and Hydride Transfer Reactions of Copper Hydrides

Eberhart, Michael Scott January 2016 (has links)
Copper hydrides such as [Ph₃PCuH]₆ (Stryker’s Reagent) are textbook reagents in organic chemistry for the selective hydrogenation of α,β-unsaturated carbonyl compounds. Despite their widespread use both stoichiometrically and catalytically, there are many important questions about polynuclear copper hydrides that have not been answered. I have investigated the electron transfer chemistry of [Ph₃PCuH]₆ and related copper hydrides. Copper hydrides (E₁/₂ = –1.0 to –1.2 V vs FcH/FcH⁺) are good one-electron reducing agents. Stopped-flow techniques have allowed the detection of electron transfer intermediates in copper hydride reactions. The fate of the copper containing products after electron transfer or hydride transfer reactions has been investigated. An unusual cationic copper hydride, [(Ph₃P)₇Cu₇H₆]⁺ was found to be the major product of these reactions. Methods of converting this species back to [Ph₃PCuH]₆ have been investigated. The chemistry of this cationic species plays an important role in catalytic use of copper hydrides.
134

Substitution and redox chemistry of ruthenium complexes / by Paul Stuart Moritz

Moritz, Paul Stuart January 1987 (has links)
Includes bibliographies / 128 leaves : ill ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Physical and Inorganic Chemistry, 1987
135

Design of monomeric and oligomeric rhenium(II/I) redox systems based on diimine and diphosphine ligands

Smithback, Joanna L. January 2006 (has links)
Thesis (Ph. D.)--University of Wyoming, 2006. / Title from PDF title page (viewed on Dec. 21, 2007). Includes bibliographical references.
136

The development and characterization of miniature spectrometers for measuring the redox status of environmental samples

Cantrell, Kevin 11 June 2001 (has links)
Graduation date: 2002
137

Selenium redox cycling isolation and characterization of a stimulatory component from tissue of loblolly pine for multiplication of somatic embryos; development of an assay to measure l-phenylalanine concentration in blood plasma /

DeSilva, Veronica January 2007 (has links)
Thesis (Ph.D)--Chemistry and Biochemistry, Georgia Institute of Technology, 2007. / Committee Chair: Sheldon May; Committee Members: Nicholas Hud, Stanley Pollock, James Powers, and Gerald Pullman. Part of the SMARTech Electronic Thesis and Dissertation Collection.
138

Reducing of iron corrosion in water pipelines by hydrogen addition

Alenazey, Feraih Sh. January 1900 (has links)
Thesis (M.S.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains xiii, 93 p. : ill. (some col.), map (part col.). Includes abstract. Includes bibliographical references (p. 91-93).
139

Thermal and photochemical behaviour of some tetramine complexes of ruthenium II and III /

Lau, Tai-chu. January 1982 (has links)
Thesis--Ph. D., University of Hong Kong, 1982. / Cover title.
140

Synthesis and redox behaviour of some tetramine complexes of ruthenium III and iridium III /

Tang, Tin-wu. January 1982 (has links)
Thesis--Ph. D., University of Hong Kong, 1982.

Page generated in 0.1717 seconds