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Directive effects in the sulfonation of iodobenzene :|banionic hyperconjugation and lithium amides ; high pressure studies on organic compoundsThompson, Evan M 01 June 1965 (has links)
The isomer distribution in the sulfonation of iodobenzene at -12.5°C. with sulfur tr~oxide (S-35) in liquid sulfur dioxide was found to be 1.40 ± 0.11% ortho, 0.34 ± 0.11% meta, and 98.26 ± 0.11% para. Pure sodium salts of each of the isomers were made from the corresponding aminobenzenesulfonic acids. After dilution with an aliquot of the sulfonation mixture, the salts were purified by recrystallization and were counted by liquid scintillation counting. Attempts to determine the relative rate of sulfonation between toluene and iodobenzene failed. The radioactive sodium p-iodobenzene sulfonate could not be separated from sodium p-toluenesulfonate by recrystallization. The lithium amides of methylamine, ethylamine, isopropylamine, tert-butylamine and 2-aminopropane-2-d were prepared from phenyl lithium and the amines. Infrared spectra of the amides were scanned in the C-H region. Comparison of the spectra of the amides and the amines showed no shifts like those found for the corresponding alcohol-alkoxide spectra. It was therefore concluded that anionic hyperconjugation could not account for the shift in the spectra of the alcohol-alkoxide system. The behavior of cyclooctatetraene, the silver adduct of cyclooctatetraene, norbornadiene, diphenylacetylene, tetraphenylcyclobutadiene-palladium chloride and ferrocene was studied under high pressures ranging from 15 to 55 kats. and with temperatures from 25 to 850°C. This work was carried out with Hall's tetrahedral anvil apparatus. If the temperature was high enough each of these compounds was found to decompose. When the temperature was below the decomposition temperature, cyclooctatetraene, diphenylacetylene and norbornadiene polymerized. No evidence of a valence tautomerization was found. The silver adduct of cyclooctatetraene and tetraphenylcyclobutadiene-palladium chloride decomposed at high temperatures. No other results were noted with these two compounds. Ferrocene underwent decomposition by iron catalysis to a mixture of iron carbides at pressures from ambient to 55 kats. and temperatures above 500°C. The same products were observed if no iron was added and the temperature and pressure were 55 kats. and 800°C., respectively. A preliminary spectrophotometric study of benzonitrile in 25%-ethyl alcohol-75% water was carried out. Cupric bromide and hydrobromic acid or cupric chloride and hydrochloric acid were added to constant ionic-strength solutions of benzonitrile. No evidence was found in the ultraviolet region for any complex ion formation. The same results were found for p-fluorobenzonitrile.
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Photocatalytic hydrogen evolution by using organic semiconductors nanoparticlesSulaimani, Shahad 11 1900 (has links)
Abstract: With the worldwide dependence on non-renewable fossil fuels and increasing
concerns over their impact on our planet through greenhouse gas emissions
finding an alternative source of clean energy is a global imperative. The solar
energy is one source of renewable energy resources, and It has the highest
potential to contribute substantially to the future of carbon-free power needs. Solar
to hydrogen has attracted much attention in the past decade due to its abundance
and the spotlessness of hydrogen as fuel for energy usage. However, practically
the requirements to convert solar energy to hydrogen, require a stable
photocatalyst that’s able to operate efficiently over a wide range of the UV-VIS
spectrum. Organic semiconductors have been widely used in hydrogen evolution
due to their earth abundance, aqueous stability, and optical absorption that can be
tuned to the UV-VIS spectrum.
In chapter 3, The effect of different sacrificial regents on hydrogen evolution activity
was systemically investigated by using poly(9,9-dioctylfluorene-alt-benzothiadiazole)
(F8BT) nanoparticles dispersion large and small diameter with Sodium dodecyl sulfate
(SDS) as stabilizer. Ascorbic acid (AA), diethylamine (DEA), triethanolamine (TEOA),
and triethylamine mixed with methanol (TEA/MeOH) were chosen as sacrificial
reagents. The results indicate that the large diameter give improved efficiency with
ascorbic acid, and the small diameter improved activity in the presence of
diethylamine. The results indicated that the comparison between different sacrificial
reagents is difficult because, the conditions of every experiment is different to
another, depending on (the type of photocatalyst used, solubility, activity..) so to
date, there is no clear concurrence in which sacrificial reagent is better than others.
Photocatalysts formed from a single organic semiconductor typically suffer from
inefficient intrinsic charge generation, which leads to low photocatalytic activities.
In chapter 4, To overcome this limitation, we have used BTR, O-IDTBR, and PC71BM
in binary and tertiary heterojunction nanoparticles between non fullerene donors’ small
molecules and fullerene acceptor. The resulting photocatalyst display
unprecedentedly a high hydrogen evolution rate over 12000 μmolh-1g-1 under AM 1.5g
illumination.
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Dectin-1 Promotes Fungicidal Activity of Human NeutrophilsKennedy, Adam D., Willment, Janet A., Dorward, David W., Williams, David L., Brown, Gordon D., DeLeo, Frank R. 01 February 2007 (has links)
Human polymorphonuclear leukocytes (PMN) are a first line of defense against fungal infections. PMN express numerous pattern recognition receptors (PRR) that facilitate identification of invading microorganisms and ultimately promote resolution of disease. Dectin-1 (β-glucan receptor) is a PRR expressed on several cell types and has been studied on monocytes and macrophages. However, the role played by dectin-1 in the recognition and killing of fungi by PMN is unknown. We investigated the ability of dectin-1 to mediate human PMN phagocytosis and fungicidal activity. Dectin-1 was expressed on the surface of PMN from all subjects tested (n=29) and in an intracellular compartment that co-sedimented with azurophilic granules in Percoll density gradients. Soluble β-glucan and mAb GE2 (anti-dectin-1) inhibited binding and phagocytosis of zymosan by human PMN (e.g., ingestionwas inhibited 40.1% by 3O min, p<0.001), and blocked reactive oxygen species production. Notably, soluble β-glucan and GE2 inhibited phagocytosis and killing of Candida albicans by PMN (inhibition of killing was 54.8% for β-glucan and 36.2% for GE2, p<0.01). Our results reveal a mechanism whereby PMN dectin-1 plays a key role in the recognition and killing of fungal pathogens by the innate immune system.
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The Human β-Glucan Receptor Is Widely Expressed and Functionally Equivalent to Murine Dectin-1 on Primary CellsWillment, Janet A., Marshall, Andrew S., Reid, Delyth M., Williams, David L., Wong, Simon Y.C., Gordon, Siamon, Brown, Gordon D. 01 May 2005 (has links)
We identified the C-type-lectin-like receptor, Dectin-1, as the major receptor for fungal β-glucans on murine macrophages and have demonstrated that it plays a significant role in the cellular response to these carbohydrates. Using two novel, isoform-specific mAb, we show here that human Dectin-1, the β-glucan receptor (βGR), is widely expressed and present on all monocyte populations as well as macrophages, DC, neutrophils and eosinophils. This receptor is also expressed on B cells and a subpopulation of T cells, demonstrating that human Dectin-1 is not myeloid restricted. Both major functional βGR isoforms - βGR-A and βGR-B - were expressed by these cell populations in peripheral blood; however, only βGR-B was significantly expressed on mature monocyte-derived macrophages and immature DC, suggesting cell-specific control of isoform expression. Inflammatory cells, recruited in vivo using a new skin-window technique, demonstrated that Dectin-1 expression was not significantly modulated on macrophages during inflammation, but is decreased on recruited granulocytes. Despite previous reports detailing the involvement of other β-glucan receptors on mature human macrophages, we have demonstrated that Dectin-1 acted as the major β-glucan receptor on these cells and contributed to the inflammatory response to these carbohydrates.
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Synthesis and Properties of Electron-Deficient Polycyclic Aromatic Compounds / 電子受容性の多環芳香族化合物の合成と性質Chaolumen 23 March 2017 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第20392号 / 工博第4329号 / 新制||工||1671(附属図書館) / 京都大学大学院工学研究科物質エネルギー化学専攻 / (主査)教授 村田 靖次郎, 教授 近藤 輝幸, 教授 小澤 文幸 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM
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Intravital Microscopy of the Parietal Peritoneum Microcirculation and the Role of Syndecan-1 in Staphylococcus aureus Infection in Peritoneal Dialysis / Role of Syndecan-1 in Peritoneal Dialysis and PeritonitisKowalewska, Paulina M January 2014 (has links)
Chronic peritonitis contributes to technique failure in peritoneal dialysis (PD), an effective replacement therapy for chronic kidney failure. Staphylococcus aureus infection is one of the most common causes of peritonitis in PD. Interestingly, mice deficient in the cell surface heparan sulfate proteoglycan, syndecan-1, were reported to clear S. aureus corneal infection more effectively than wild-type mice. The objectives of this study were to examine the protein expression and role of syndecan-1 in leukocyte recruitment, chemokine presentation and S. aureus infection in the microcirculation underlying the parietal peritoneum in wild-type and syndecan-1-/- mice.
Immunofluorescence intravital microscopy (IVM) of the parietal peritoneum microcirculation revealed that syndecan-1 was localized to the subendothelial region of venules and the mesothelial layer but does not regulate leukocyte recruitment and is not necessary for presentation of the chemokine MIP-2 in peritoneal venules. IVM was also used to study the effects of a conventional PD solution injected through a peritoneal catheter in a mouse PD model. After 6 weeks of dialysis, the peritoneal catheter implant increased leukocyte rolling and extravasation, fibrosis and angiogenesis in the parietal peritoneum independently from the dialysis solution treatment. Furthermore, the role of syndecan-1 was examined using a 4 week PD model. Four hours after infection with S. aureus through the dialysis catheter or intraperitoneal injection, the dialyzed syndecan-1-/- mice were more susceptible to S. aureus infection than undialyzed syndecan-1-/- controls and wild-type animals. IVM showed that in S. aureus infection, syndecan-1 was removed from the subendothelial surface of peritoneal venules but syndecan-1 deficiency did not affect leukocyte recruitment during S. aureus infection.
This study indicates that syndecan-1 in the peritoneum and microcirculation is not a regulator of inflammatory responses but is crucial for providing a barrier to S. aureus infection, which may have important implications for susceptibility to S. aureus infections in PD. / Dissertation / Doctor of Philosophy (Medical Science)
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Synthesis and Hybridization Studies of Oligoribonucleotides Corresponding to the Common, Double-Stranded Region of the Dihydrouridine Arm of Several Transfer RNA MoleculesEngland, Thomas Edward 10 1900 (has links)
<p> An improved method for the synthesis of oligoribonucleotides of defined sequence was developed. The general phosphotriester synthesis of Neilson and co-workers was modified by the introduction of a new condensing agent, mesitylenesulfonyl-1,2,4-triazole, and by the replacement of the bis(cyclohexylammonium) salt of mono-2,2,2-trichloroethyl phosphate with its acid salt. These modifications provided significant increases in the yields for the condensation of protected nucleosides - especially in the case of purine residues. Finally, modification of the three-step procedure for the deprotection of protected oligoribonucleotides resulted in the isolation of oligomers of exceptional purity and biological activity.</p> <p> Oligomers corresponding to natural sequences in transfer RNA molecules were obtained by this improved method of synthesis. These oligomers were then used to study:
1. The formation of short double-stranded RNA helices and
2. The interactions of aminoacyl-tRNA ligases with tRNA fragments.</p> / Thesis / Doctor of Philosophy (PhD)
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The Actomyosin-Like Protein of Naegleria Gruberi AmoebaLastovica, Albert J. 05 1900 (has links)
<p> Amoeboid Motion is thought to be due to the action of an actomyosin-
like protein present in the cytoplasm of amoeba. A co-ordinated net-
0 work of microfilaments of the actomyosin-like protein, 70 A in diameter,
may be the mechanical means of accomplishing amoeboid motion. The microfilaments
formed of the actomyosin-like protein, may be capable of rapid
association and dissociation in vivo.
In this thesis, the cytoplasm of Naegleria gruberi amoeba has been
shown to possess a protein similar to actomyosin. Characterization of the
ATPase activity, superprecipitating ability, electrophoretic behaviour and
microfilament producing ability reveal that the actomyosin-like protein
of Naegleria gruberi amoeba is quite similar to the analogous protein in
Physarum polycephalum. Naeqleria gruberi may be an ideal organism in which
to study the interconversion of one form of a biologically active macromolecule
to another., In different stages of the life cycle, amoeboid motion,
flagellar beating and mitotic spindles are present. It is possible
that the same contractile molecules in different forms may perform different
functions. </P> / Thesis / Master of Science (MSc)
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Electronic Correlation in C60 and Other MoleculesLin, Fei January 2003 (has links)
<p> In this thesis, we investigate the possibility that a purely electronic mechanism is the cause of superconductivity in C60 materials. Several computational methods are adopted to calculate the pair-binding energy. They are perturbation theory, exact diagonalization, Gutzwiller projection, and auxiliary field Monte Carlo. Results from these different methods are compared with each other both in a C60 molecule and in other smaller molecules in order to test conclusions about whether or not a purely electronic mechanism can lead to an attractive interactions between electrons in C60 molecules.</p> <p> Besides this test of the superconductivity mechanism, we also explain in detail how to apply these different computational methods to C60 for the specific geometry of C60. Clearly illustrating these computational methods is the second goal of this thesis.</p> <p> Our final conclusion is that for both small and large Hubbard interaction U, there is pair binding in a single C60 molecule. For intermediate Hubbard interaction strength, there is no clear evidence for pair binding for the range of temperatures we explored. We suggest that the truncation of the Coulomb interaction, which is implicit in the Hubbard Hamiltonian, may suppress pair-binding of electrons in C60 and that it may be necessary to consider a model that includes the long range character of Coulomb interaction. This is a subject for further study.</p> / Thesis / Master of Science (MSc)
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THE ROLE OF CELL SURFACE GRP78 AND ANTI-GRP78 AUTOANTIBODIES IN THE DEVELOPMENT AND PROGRESSION OF ATHEROSCLEROTIC LESIONSCrane, Elizabeth January 2016 (has links)
Damage to the endothelium is an important contributor to the initiation and progression of atherosclerosis. GRP78 is an endoplasmic reticulum (ER)-resident molecular chaperone in normal healthy endothelium that functions to assist in the correct folding of newly synthesized proteins and to prevent the aggregation of folding intermediates. In addition, GRP78 is present as a transmembrane protein on the surface of lesion-resident endothelial cells. Surface GRP78 is known to act as a surface signaling receptor in cancer cells and is activated by anti-GRP78 autoantibodies (GRP78a-Abs) isolated from the serum of cancer patients. However, the role of cell surface GRP78 on endothelial cells and the influence of GRP78a-Abs in atherosclerosis is unknown. The objectives of this study were to investigate the effects of GRP78a-Abs on lesion development, examine whether engagement of cell surface GRP78 by GRP78a-Abs modulates endothelial cell function, and determine whether GRP78a-Abs were associated with cardiovascular disease (CVD) in humans. This research showed that ApoE-/- mice with advanced atherosclerotic lesions have elevated serum levels of GRP78a-Abs and ApoE-/- mice immunized against recombinant GRP78 demonstrated a significant increase in GRP78a-Abs titers as well as accelerated lesion growth. Furthermore, this work demonstrated that activation of surface GRP78 on endothelial cells by GRP78a-Abs significantly increases gene expression of adhesion molecules ICAM-1 and VCAM-1 as well as leukocyte adhesion through the NFκB pathway. Additionally, middle-aged to elderly adults at risk for CVD showed a tendency toward elevated circulating GRP78a-Ab levels. Our results suggest that signaling through cell surface GRP78 can activate intracellular pathways that contribute to endothelial cell activation and augment atherosclerotic lesion development. These findings demonstrate a novel role for GRP78a-Abs and surface GRP78 receptor activity in endothelial cell function and the early stages of lesion development, as well as establish an initial framework for future work involving circulating GRP78a-Abs and atherosclerotic disease in humans. Furthermore, this work indicates inhibiting the interaction of GRP78a-Abs with cell surface GRP78 could present a novel therapeutic strategy to modulate lesion growth, thereby reducing the risk for atherosclerosis and cardiovascular disease. / Thesis / Doctor of Philosophy (PhD)
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