Miniaturized and portable microfluidic analytical platforms have been widely explored in the broad field of chemical analysis. The concept of microfluidics offer a number of important advantages, including low reagent consumption, low-cost detection, high sample throughput, and shorter analysis time. Semiconductor nanocrystals or quantum dots have been extensively utilized in...
Melanocytes are dendritic, pigment-producing cells located in the skin and are responsible for its protection against the deleterious effects of solar ultraviolet radiation (UVR), which include DNA damage and elevated reactive oxygen species (ROS). They do so by synthesizing photoprotective melanin pigments and distributing them to adjacent skin cells (e.g.,...
Polyoxometalates are discrete anionic oxo clusters of the Group V and VI transition metals that can be conceptualized as molecular metal oxides. Because they are pairable with any alkali cation, a great deal of fundamental chemistry can be gleaned from their study, including solubility trends and insight into cation binding...
Two major types of glycerol dialkyl glycerol tetraethers (GDGTs) are commonly
used in paleoecological and paleoclimatological reconstructions: isoprenoidal and
branched GDGTs. In aquatic environments, it was originally assumed that isoprenoidal
GDGTs, especially crenarchaeol, derive mainly from aquatic Thaumarchaeota, whilst
branched GDGTs are an allochthonous input derived from soil Bacteria. Recently,...
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(Fig. 3A-J), although the 219
environmental conditions as well as pathways and amounts of terrestrial
In the North Atlantic, cold, relatively salty water sinks in the icy Labrador and Greenland seas, forming North Atlantic Deep Water (NADW). This circulates through the global ocean, driving ocean overturning and global heat transport and, thus, impacting global climate. As one of the most climatically sensitive regions on Earth,...
The goals of this dissertation are centered on understanding changes in Earth surface and climate systems through the use of geologic proxies as records of past changes in these systems. Specifically, this dissertation (1) establishes a new chronology for retreat of the Ross Sea sector of the West Antarctic Ice...
The Lena River in central Siberia is one of the
major pathways translocating terrestrial organic matter (OM)
from its vast catchment area to the coastal zone of the Laptev
Sea and the Arctic Ocean. The permafrost soils of its far
south-stretching catchment, which store huge amounts of
OM, will most...
The Lena River in central Siberia is one of the
major pathways translocating terrestrial organic matter (OM)
from its vast catchment area to the coastal zone of the Laptev
Sea and the Arctic Ocean. The permafrost soils of its far
south-stretching catchment, which store huge amounts of
OM, will most...
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– Part 2: Lignin-derived
phenol compositions
Winterfeld, M., Goñi, M. A., Just, J., Hefter, J
The goal of dissertation research was to use geochemical, statistical and geological methods to constrain and understand climate variability over several different time scales. Specifically, I have addressed three questions regarding past climate change: (1) how does the record of Irish cirque glaciers constrain the dimensions of the Irish Ice...
Small-angle X-ray scattering (SAXS) studies of aqueous [Ta₆O₁₉]⁸⁻
compared to prior studies of aqueous [Nb₆O₁₉]⁸⁻ reveals key
differences in behaviour, which is likely at the root of the difficultly
in developing polyoxotantalate chemistry. Specifically, where
contact ion-pairing dominates between [Nb₆O₁₉]⁸⁻ and its
counterions, solvent-separated ion-pairing between [Ta₆O₁₉]⁸⁻
and its counterions...
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. Tang, Z. Shi, S. Ouyang and
J. Ye, J. Am. Chem. Soc., 2012, 134, 19716.
21 Y. Marcus and G. Hefter