275 research outputs found
Room temperature negative differential resistance of a monolayer molecular rotor device
An electrically driven molecular rotor device comprised of a monolayer of redox-active ligated copper compounds sandwiched between a gold electrode and a highly doped P+Si substrate was fabricated. Current-voltage spectroscopy revealed a temperature-dependent negative differential resistance (NDR) associated with the device. Time-dependent density functional theory suggests the source of the observed NDR to be redox-induced ligand rotation around the copper metal center, an explanation consistent with the proposed energy diagram of the device. An observed temperature dependence of the NDR behavior further supports this hypothesis
Clinical academic career pathway for nursing and allied health professionals: clinical academic role descriptors
The clinical academic pathway outlined highlights the range of typical practice and research-focused activities that a practitioner on a clinical academic career pathway might normally engage in at different levels and points along this career path. The activities are intended as a guide for practitioners interested in learning more about the practice and research components of a clinical academic career, as well as those already employed in clinical academic roles. They may also be useful for health care organisations and Higher Education Institutions as a tool for developing clinical academic roles
Application of Palladium-Mediated 18F-Fluorination to PET Radiotracer Development: Overcoming Hurdles to Translation
New chemistry methods for the synthesis of radiolabeled small molecules have the potential to impact clinical positron emission tomography (PET) imaging, if they can be successfully translated. However, progression of modern reactions from the stage of synthetic chemistry development to the preparation of radiotracer doses ready for use in human PET imaging is challenging and rare. Here we describe the process of and the successful translation of a modern palladium-mediated fluorination reaction to non-human primate (NHP) baboon PET imaging–an important milestone on the path to human PET imaging. The method, which transforms [18F]fluoride into an electrophilic fluorination reagent, provides access to aryl–18F bonds that would be challenging to synthesize via conventional radiochemistry methods.Chemistry and Chemical Biolog
Room temperature negative differential resistance of a monolayer molecular rotor device
Polymorphs and hydrates of acyclovir
Acyclovir (ACV) has been commonly used as an antiviral for decades. Although the crystal structure of the commercial form, a 3:2 ACV/water solvate, has been known since 1980s, investigation into the structure of anhydrous ACV has been limited. Here, we report the characterization of four anhydrous forms of ACV and a new hydrate in addition to the known hydrate. Two of the anhydrous forms appear as small needles and are stable to air exposure, whereas the third form is morphologically similar but quickly absorbs water from the atmosphere and converts back to the commercial form. The high-temperature modification is achieved by heating anhydrous form I above 180°C. The crystal structures of anhydrous form I and a novel hydrate are reported for the first time. © 2010 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 100:949–963, 2011Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/79417/1/22336_ftp.pd
Separation of rare gases and chiral molecules by selective binding in porous organic cages
The separation of molecules with similar size and shape is an important technological challenge. For example, rare gases can pose either an economic opportunity or an environmental hazard and there is a need to separate these spherical molecules selectively at low concentrations in air. Likewise, chiral molecules are important building blocks for pharmaceuticals, but chiral enantiomers, by definition, have identical size and shape, and their separation can be challenging. Here we show that a porous organic cage molecule has unprecedented performance in the solid state for the separation of rare gases, such as krypton and xenon. The selectivity arises from a precise size match between the rare gas and the organic cage cavity, as predicted by molecular simulations. Breakthrough experiments demonstrate real practical potential for the separation of krypton, xenon and radon from air at concentrations of only a few parts per million. We also demonstrate selective binding of chiral organic molecules such as 1-phenylethanol, suggesting applications in enantioselective separation
Slow dynamics and aging in a non-randomly frustrated spin system
A simple, non-disordered spin model has been studied in an effort to
understand the origin of the precipitous slowing down of dynamics observed in
supercooled liquids approaching the glass transition. A combination of Monte
Carlo simulations and exact calculations indicates that this model exhibits an
entropy vanishing transition accompanied by a rapid divergence of time scales.
Measurements of various correlation functions show that the system displays a
hierarchy of time scales associated with different degrees of freedom. Extended
structures, arising from the frustration in the system, are identified as the
source of the slow dynamics. In the simulations, the system falls out of
equilibrium at a temperature higher than the entropy-vanishing
transition temperature and the dynamics below exhibits aging as
distinct from coarsening. The cooling rate dependence of the energy is also
consistent with the usual glass formation scenario.Comment: 41 pages, 16 figures. Bibliography file is correcte
Separation of rare gases and chiral molecules by selective binding in porous organic cages
The separation of molecules with similar size and shape is an important technological challenge. For example, rare gases can pose either an economic opportunity or an environmental hazard and there is a need to separate these spherical molecules selectively at low concentrations in air. Likewise, chiral molecules are important building blocks for pharmaceuticals, but chiral enantiomers, by definition, have identical size and shape, and their separation can be challenging. Here we show that a porous organic cage molecule has unprecedented performance in the solid state for the separation of rare gases, such as krypton and xenon. The selectivity arises from a precise size match between the rare gas and the organic cage cavity, as predicted by molecular simulations. Breakthrough experiments demonstrate real practical potential for the separation of krypton, xenon and radon from air at concentrations of only a few parts per million. We also demonstrate selective binding of chiral organic molecules such as 1-phenylethanol, suggesting applications in enantioselective separation
2000 Wild Blueberry Project Reports
The 2000 edition of the Wild Blueberry Project Reports was prepared for the Maine Wild Blueberry Commission and the University of Maine Wild Blueberry Advisory Committee by researchers at the University of Maine, Orono. Projects in this report include:
1. Determination of Pesticide Residue Levels in Fresh and Processed Wild Blueberries
2. Factors Affecting the Microbiological Quality of IQF Blueberries
3. Effect of Processed Blueberry Products on Oxidation in Meat Based Food Systems
4. Separation of Maggot Infested Wild Blueberries in the IQF Processing Line
5. Water Use of Wild Blueberries
6. Control Tactics for Blueberry Pest Insects, 2000
7. IPM Strategies
8. Biology and Ecology of Blueberry Pest Insects
9. Survey of Stem Blight and Leaf Spot Diseases in Lowbush Blueberry Fields
10. Phosphorus/Nitrogen Fertilizer Ratio
11. Effect of Boron Application Methods on Boron Uptake in Lowbush Blueberries
12. Effect of Foliar Iron and Copper Application on Growth and Yield of Lowbush Blueberries
13. Effect of Soil pH on Nutrient Uptake
14. Effect of Nutri-Phite (tm) P+K on Growth and Yield of Lowbush Blueberry
15. Effect of Fertilizer Timing on Lowbush Blueberry Growth and Productivity
16. Assessment of Azafenidin for Weed Control in Wild Blueberries
17. Assessment of Rimsulfuron for Weed Control in Wild Blueberries
18. Assessment of Pendimethalin for Weed Control in Wild Blueberries
19. Assessment of VC1447 for Weed Control in Wild Blueberries
20. Cultural Management Using pH for Weed Control in Wild Blueberries
21. Evaluation of Sprout-Less Weeder® for Weed Control in Wild Blueberries
22. Evaluation of RoundUp Ultra® and Touchdown 5® for Weed Control in Wild Blueberries
23. Evaluation and Demonstration of Techniques for Filling in Bare Spots in Wild Blueberry Fields
24. Evaluation of Fungicides Efficacy in Wild Blueberry Fields
25. Velpar® and Sinbar/Karmex® Demonstration Plot Comparison Trial
26. Blueberry Extension Education Program in 2000
27. 2000 Hexazinone Groundwater Surve
Canvass: a crowd-sourced, natural-product screening library for exploring biological space
NCATS thanks Dingyin Tao for assistance with compound characterization. This research was supported by the Intramural Research Program of the National Center for Advancing Translational Sciences, National Institutes of Health (NIH). R.B.A. acknowledges support from NSF (CHE-1665145) and NIH (GM126221). M.K.B. acknowledges support from NIH (5R01GM110131). N.Z.B. thanks support from NIGMS, NIH (R01GM114061). J.K.C. acknowledges support from NSF (CHE-1665331). J.C. acknowledges support from the Fogarty International Center, NIH (TW009872). P.A.C. acknowledges support from the National Cancer Institute (NCI), NIH (R01 CA158275), and the NIH/National Institute of Aging (P01 AG012411). N.K.G. acknowledges support from NSF (CHE-1464898). B.C.G. thanks the support of NSF (RUI: 213569), the Camille and Henry Dreyfus Foundation, and the Arnold and Mabel Beckman Foundation. C.C.H. thanks the start-up funds from the Scripps Institution of Oceanography for support. J.N.J. acknowledges support from NIH (GM 063557, GM 084333). A.D.K. thanks the support from NCI, NIH (P01CA125066). D.G.I.K. acknowledges support from the National Center for Complementary and Integrative Health (1 R01 AT008088) and the Fogarty International Center, NIH (U01 TW00313), and gratefully acknowledges courtesies extended by the Government of Madagascar (Ministere des Eaux et Forets). O.K. thanks NIH (R01GM071779) for financial support. T.J.M. acknowledges support from NIH (GM116952). S.M. acknowledges support from NIH (DA045884-01, DA046487-01, AA026949-01), the Office of the Assistant Secretary of Defense for Health Affairs through the Peer Reviewed Medical Research Program (W81XWH-17-1-0256), and NCI, NIH, through a Cancer Center Support Grant (P30 CA008748). K.N.M. thanks the California Department of Food and Agriculture Pierce's Disease and Glassy Winged Sharpshooter Board for support. B.T.M. thanks Michael Mullowney for his contribution in the isolation, elucidation, and submission of the compounds in this work. P.N. acknowledges support from NIH (R01 GM111476). L.E.O. acknowledges support from NIH (R01-HL25854, R01-GM30859, R0-1-NS-12389). L.E.B., J.K.S., and J.A.P. thank the NIH (R35 GM-118173, R24 GM-111625) for research support. F.R. thanks the American Lebanese Syrian Associated Charities (ALSAC) for financial support. I.S. thanks the University of Oklahoma Startup funds for support. J.T.S. acknowledges support from ACS PRF (53767-ND1) and NSF (CHE-1414298), and thanks Drs. Kellan N. Lamb and Michael J. Di Maso for their synthetic contribution. B.S. acknowledges support from NIH (CA78747, CA106150, GM114353, GM115575). W.S. acknowledges support from NIGMS, NIH (R15GM116032, P30 GM103450), and thanks the University of Arkansas for startup funds and the Arkansas Biosciences Institute (ABI) for seed money. C.R.J.S. acknowledges support from NIH (R01GM121656). D.S.T. thanks the support of NIH (T32 CA062948-Gudas) and PhRMA Foundation to A.L.V., NIH (P41 GM076267) to D.S.T., and CCSG NIH (P30 CA008748) to C.B. Thompson. R.E.T. acknowledges support from NIGMS, NIH (GM129465). R.J.T. thanks the American Cancer Society (RSG-12-253-01-CDD) and NSF (CHE1361173) for support. D.A.V. thanks the Camille and Henry Dreyfus Foundation, the National Science Foundation (CHE-0353662, CHE-1005253, and CHE-1725142), the Beckman Foundation, the Sherman Fairchild Foundation, the John Stauffer Charitable Trust, and the Christian Scholars Foundation for support. J.W. acknowledges support from the American Cancer Society through the Research Scholar Grant (RSG-13-011-01-CDD). W.M.W.acknowledges support from NIGMS, NIH (GM119426), and NSF (CHE1755698). A.Z. acknowledges support from NSF (CHE-1463819). (Intramural Research Program of the National Center for Advancing Translational Sciences, National Institutes of Health (NIH); CHE-1665145 - NSF; CHE-1665331 - NSF; CHE-1464898 - NSF; RUI: 213569 - NSF; CHE-1414298 - NSF; CHE1361173 - NSF; CHE1755698 - NSF; CHE-1463819 - NSF; GM126221 - NIH; 5R01GM110131 - NIH; GM 063557 - NIH; GM 084333 - NIH; R01GM071779 - NIH; GM116952 - NIH; DA045884-01 - NIH; DA046487-01 - NIH; AA026949-01 - NIH; R01 GM111476 - NIH; R01-HL25854 - NIH; R01-GM30859 - NIH; R0-1-NS-12389 - NIH; R35 GM-118173 - NIH; R24 GM-111625 - NIH; CA78747 - NIH; CA106150 - NIH; GM114353 - NIH; GM115575 - NIH; R01GM121656 - NIH; T32 CA062948-Gudas - NIH; P41 GM076267 - NIH; R01GM114061 - NIGMS, NIH; R15GM116032 - NIGMS, NIH; P30 GM103450 - NIGMS, NIH; GM129465 - NIGMS, NIH; GM119426 - NIGMS, NIH; TW009872 - Fogarty International Center, NIH; U01 TW00313 - Fogarty International Center, NIH; R01 CA158275 - National Cancer Institute (NCI), NIH; P01 AG012411 - NIH/National Institute of Aging; Camille and Henry Dreyfus Foundation; Arnold and Mabel Beckman Foundation; Scripps Institution of Oceanography; P01CA125066 - NCI, NIH; 1 R01 AT008088 - National Center for Complementary and Integrative Health; W81XWH-17-1-0256 - Office of the Assistant Secretary of Defense for Health Affairs through the Peer Reviewed Medical Research Program; P30 CA008748 - NCI, NIH, through a Cancer Center Support Grant; California Department of Food and Agriculture Pierce's Disease and Glassy Winged Sharpshooter Board; American Lebanese Syrian Associated Charities (ALSAC); University of Oklahoma Startup funds; 53767-ND1 - ACS PRF; PhRMA Foundation; P30 CA008748 - CCSG NIH; RSG-12-253-01-CDD - American Cancer Society; RSG-13-011-01-CDD - American Cancer Society; CHE-0353662 - National Science Foundation; CHE-1005253 - National Science Foundation; CHE-1725142 - National Science Foundation; Beckman Foundation; Sherman Fairchild Foundation; John Stauffer Charitable Trust; Christian Scholars Foundation)Published versionSupporting documentatio
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