University of Wisconsin–Milwaukee

About: University of Wisconsin–Milwaukee is a education organization based out in Milwaukee, Wisconsin, United States. It is known for research contribution in the topics: Population & Gravitational wave. The organization has 11839 authors who have published 28034 publications receiving 936438 citations. The organization is also known as: UWM & University of Wisconsin-Milwaukee.

Spontaneous Dissociation of CO2 to CO on Defective Surface of Cu(I)/TiO2–x Nanoparticles at Room Temperature

Abstract: The activation of CO2 on defective surface of Cu(I)/TiO2–x has been studied using in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). It was demonstrated that CO2– species, generated upon an electron attachment to CO2, are spontaneously dissociated into CO even in the dark on a partially oxygen depleted Cu(I)/TiO2–x surface prepared by thermal annealing in an inert environment. The formation of CO bound on Cu+ sites was identified in the DRIFT spectra, and isotopic carbon-labeling experiments confirmed that the produced CO was derived from CO2. The spontaneous dissociation of CO2– in the dark is to a large extent associated with the surface oxygen vacancies that provide not only the electronic charge (i.e., formation of Ti3+) but also the sites for the adsorption of oxygen atoms from CO2. The surface Cu+ species may facilitate destabilizing adsorbed CO2– and enhance its subsequent dissociation to CO. The defective surface is much more active than defect-free surface; the healed o...

A Radio Counterpart to a Neutron Star Merger

Abstract: Gravitational waves have been detected from a binary neutron star merger event, GW170817. The detection of electromagnetic radiation from the same source has shown that the merger occurred in the outskirts of the galaxy NGC 4993, at a distance of 40 megaparsecs from Earth. We report the detection of a counterpart radio source that appears 16 days after the event, allowing us to diagnose the energetics and environment of the merger. The observed radio emission can be explained by either a collimated ultra-relativistic jet viewed off-axis, or a cocoon of mildly relativistic ejecta. Within 100 days of the merger, the radio light curves will distinguish between these models and very long baseline interferometry will have the capability to directly measure the angular velocity and geometry of the debris.

Relationships between Hippocampal Sharp Waves, Ripples, and Fast Gamma Oscillation: Influence of Dentate and Entorhinal Cortical Activity

Abstract: Hippocampal sharp waves (SPWs) and associated fast (“ripple”) oscillations (SPW-Rs) in the CA1 region are among the most synchronous physiological patterns in the mammalian brain. Using two-dimensional arrays of electrodes for recording local field potentials and unit discharges in freely moving rats, we studied the emergence of ripple oscillations (140–220 Hz) and compared their origin and cellular–synaptic mechanisms with fast gamma oscillations (90–140 Hz). We show that (1) hippocampal SPW-Rs and fast gamma oscillations are quantitatively distinct patterns but involve the same networks and share similar mechanisms; (2) both the frequency and magnitude of fast oscillations are positively correlated with the magnitude of SPWs; (3) during both ripples and fast gamma oscillations the frequency of network oscillation is higher in CA1 than in CA3; and (4) the emergence of CA3 population bursts, a prerequisite for SPW-Rs, is biased by activity patterns in the dentate gyrus and entorhinal cortex, with the highest probability of ripples associated with an “optimum” level of dentate gamma power. We hypothesize that each hippocampal subnetwork possesses distinct resonant properties, tuned by the magnitude of the excitatory drive.

Hydrogen peroxide inducible DNA cross-linking agents: targeted anticancer prodrugs.

Abstract: The major concern for anticancer chemotherapeutic agents is the host toxicity. The development of anticancer prodrugs targeting the unique biochemical alterations in cancer cells is an attractive approach to achieve therapeutic activity and selectivity. We designed and synthesized a new type of nitrogen mustard prodrug that can be activated by high level of reactive oxygen species (ROS) found in cancer cells to release the active chemotherapy agent. The activation mechanism was determined by NMR analysis. The activity and selectivity of these prodrugs toward ROS was determined by measuring DNA interstrand cross-links and/or DNA alkylations. These compounds showed 60–90% inhibition toward various cancer cells, while normal lymphocytes were not affected. To the best of our knowledge, this is the first example of H2O2-activated anticancer prodrugs.