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Combined micro-Fourier transform infrared (FTIR) spectroscopy and micro-Raman spectroscopy of Proterozoic acritarchs: A new approach to Paleobiology
- Precambrian Research
, 2005
"... Abstract Micro-scale analytical techniques permit correlation of chemistry with morphology of individual Proterozoic acritarchs (organic-walled microfossils), and thus provide new approaches for elucidating their biological affinities. A combination of micro-Fourier transform infrared (FTIR) spectr ..."
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Abstract Micro-scale analytical techniques permit correlation of chemistry with morphology of individual Proterozoic acritarchs (organic-walled microfossils), and thus provide new approaches for elucidating their biological affinities. A combination of micro-Fourier transform infrared (FTIR) spectroscopy and laser micro-Raman spectroscopy was used to investigate the organic structure and composition of individual acritarchs. Well preserved Neoproterozoic acritarchs from the Tanana Formation, Australia (ca. 590-565 Ma), and Mesoproterozoic acritarchs from the Roper Group (1.5-1.4 Ga), Australia, and Ruyang Group, China (1.4-1.3 Ga, age poorly resolved but certainly >1000 Ma and <1625 Ma) have thermal maturities that range from immature to oil window. FTIR spectra of Tanarium conoideum from the Tanana Formation contain intense aliphatic C H stretching bands in the 2900 cm −1 region relative to the C C aromatic ring stretching band at 1600 cm −1 . This FTIR spectrum is consistent with the FTIR spectra obtained from algaenans isolated from extant chlorophyte and eustigmatophyte microalgae. FTIR spectra of Leiosphaeridia sp. from the Tanana Formation contain a less intense aliphatic C H stretching band relative to the C C aromatic ring stretching band. By comparison, the spectra acquired from the Mesoproterozoic acritarchs were dominated by C C aromatic ring stretching bands at 1600 cm −1 relative to moderate-weak CH 3 terminal groups (1345 cm −1 ), C H aliphatic stretching (3000-2700 cm −1 ), and C O (1710 cm −1 ), although some differences in biopolymer composition occurred between species. Curve-fitting of the aliphatic C H x stretching region provides greater insight into the aliphatic structures of the acritarchs. The CH 2 /CH 3 intensity ratio can be used to assess the relative chain length and degree of branching. Organic material in the Tanarium conoideum consists of straight long chain hydrocarbons, while the other acritarchs contain hydrocarbons consisting of short chains that are highly branched. In this study it was found that Raman spectroscopy does not provide additional information about biopolymer composition of Proterozoic acritarchs, but rather offers complementary data regarding the aromaticity and degree of saturation of the macromolecular structure of acritarch cysts.
A Review of Molecular Mechanisms of the Anti-Leukemic Effects of Phenolic Compounds in Honey
, 2012
"... Abstract: Hematologic malignancies constitute about 9 % of all new cases of cancers as reported via the GLOBOCAN series by International Agency for Research on Cancer (IARC) in 2008. So far, the conventional therapeutic and surgical approaches to cancer therapy have not been able to curtail the risi ..."
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Abstract: Hematologic malignancies constitute about 9 % of all new cases of cancers as reported via the GLOBOCAN series by International Agency for Research on Cancer (IARC) in 2008. So far, the conventional therapeutic and surgical approaches to cancer therapy have not been able to curtail the rising incidence of cancers, including hematological malignancies, worldwide. The last decade has witnessed great research interest in biological activities of phenolic compounds that include anticancer, anti-oxidation and anti-inflammation, among other things. A large number of anticancer agents combat cancer through cell cycle arrest, induction of apoptosis and differentiation, as well as through inhibition of cell growth and proliferation, or a combination of two or more of these mechanisms. Various phenolic compounds from different sources have been reported to be promising anticancer agents by acting through one of these mechanisms. Honey, which has a long history of human consumption both for medicinal and nutritional uses, contains a variety of phenolic compounds such as flavonoids, phenolic acids, coumarins and tannins. This paper presents a review on the molecular mechanisms of the anti-leukemic activity of various phenolic compounds on cell cycle, cell growth and
The Poetics, Politics and Writing of Memory
, 2015
"... ePublications@SCU is an electronic repository administered by Southern Cross University Library. Its goal is to capture and preserve the intellectual output of Southern Cross University authors and researchers, and to increase visibility and impact through open access to researchers around the world ..."
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ePublications@SCU is an electronic repository administered by Southern Cross University Library. Its goal is to capture and preserve the intellectual output of Southern Cross University authors and researchers, and to increase visibility and impact through open access to researchers around the world. For further information please contact
Mazuelloids: Product of Post-Mortem Phosphatization of
"... Enigmatic microfossils from the early Silurian of Poland known as mazuelloids (5 muellerisphaerids) have been identified as Baltisphaeridium-like acanthomorphic acri-tarchs that have been subject to post-mortem phosphatiza-tion. These acritarchs were the dominant components of large post-bloom macro ..."
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Enigmatic microfossils from the early Silurian of Poland known as mazuelloids (5 muellerisphaerids) have been identified as Baltisphaeridium-like acanthomorphic acri-tarchs that have been subject to post-mortem phosphatiza-tion. These acritarchs were the dominant components of large post-bloom macroaggregates that probably sank rap-idly to the seafloor and were then overgrown by benthic coc-coid cyanobacterial mats. Early diagenetic phosphatization of the remains probably occurred following shallow burial and in proximity to decomposing phosphate-rich macroag-gregates. Depending on phosphate availability, the result-ing phosphate layers were thin or thick and were deposited on the outside, inside, or enveloping the acritarch organic walls from both sides. The unusually large size of the ma-zuelloid-forming acritarchs was probably the result of peri-odically hypertrophic conditions driven by large blooms generated by upwelling currents.
Progressive Education; Teacher Centers IDENTIFIERS Open Classrooms
, 1972
"... This document is a collection of essays on open education, the results of the Conference on Open Education held in April 1972 at the State University of New York College at Cortland.. The title of the conference, "Increasing Alternatives for Teachers and Children, " suggests the underlying ..."
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This document is a collection of essays on open education, the results of the Conference on Open Education held in April 1972 at the State University of New York College at Cortland.. The title of the conference, "Increasing Alternatives for Teachers and Children, " suggests the underlying theme for all the essays in this volume: respect for persons..As the preface states, open education is a moral statement about the worth, the individuality, the dignity, and the human rights of everyone involved in the educational enterprise.,There are 26 essays in this volume, covering topics such as open classrooms versus open schools, teacher centers as an'open approach to changine schools, structure in the open classroom, record keeping in the open classroom, the informalization of higher education, and open education in a closed society..(JA) II Supported jointly by
i ROLES OF IGH INTRONIC ENHANCER E IN CLONAL SELECTION AT THE PRE-B TO IMMATURE B CELL TRANSITION AND IN THE ELIMINATION OF AUTOREACTIVE B
, 2013
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PALYNOFACIES INSIGHT INTO PALAEOENVIRONMENTAL
, 2008
"... supergroup and palynofacies insight into ..."
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1 The Ordovician acritarch genus Coryphidium
"... Abstract: The acritarch genus Coryphidium Vavrdová 1972 is one of the most frequently recorded acritarch taxa in the Ordovician. The original diagnoses, stratigraphical ranges and geographical distribution of all Coryphidium species are critically evaluated in a review of published literature supple ..."
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Abstract: The acritarch genus Coryphidium Vavrdová 1972 is one of the most frequently recorded acritarch taxa in the Ordovician. The original diagnoses, stratigraphical ranges and geographical distribution of all Coryphidium species are critically evaluated in a review of published literature supplemented by studies of material from the British Isles, Belgium, the
Perfluorocyclobutane Aromatic Polyethers. Synthesis and Characterization of New Siloxane-Containing Fluoropolymers†
, 1995
"... ABSTRACT: The synthesis and characterization of siloxane-containing perfluorocyclobutane (PFCB) aromatic polyethers, a new class of fluorosiloxane polymers possessing a well-defined linear structure of alternating disiloxanyl-p-phenylene (cis/trans)-1,2-disubstituted perfluorocyclobutyl ether linkag ..."
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ABSTRACT: The synthesis and characterization of siloxane-containing perfluorocyclobutane (PFCB) aromatic polyethers, a new class of fluorosiloxane polymers possessing a well-defined linear structure of alternating disiloxanyl-p-phenylene (cis/trans)-1,2-disubstituted perfluorocyclobutyl ether linkages with known fluoroolefin end groups, is described. The unexpected formation of an aryl Grignard reagent from 4-[(trifluorovinyl)oxy]bromobenzene (2) allowed for the high-yield synthesis of 4-[(trifluorovinyl)oxy]-phenyldimethylsilane (3) which was dehydrogenatively hydrolyzed in situ and condensed to bis[1,3-[4-[(trifluorovinyl)oxy]phenyl]]-1,1,3,3-tetramethyldisiloxane monomer (4). Thermal cyclopolymerization in the bulk produces poly(1,1,3,3-tetramethyldisiloxanyl-p-phenylene-1-oxaperfluorocyclobutylene-2-oxa-p-phenylene) (5) as a clear, flexible, and thermally stable elastomeric film. Copolymerization of 4 with a trifunctional PFCB monomer gives a toughened thermoset with good thermal stability. Monomers and polymers were characterized by 1H, 13C, and 19F NMR and FTIR spectroscopy. Number-average molecular weights were determined by gel permeation chromatography and, when possible, quantitative 19F NMR end group analysis. Synthesis, characterization, thermal analyses, and current scope of PFCB polymer chemistry are discussed.
