3,318 research outputs found
Recommended from our members
Efficacy and safety of sodium zirconium cyclosilicate in patients with baseline serum potassium level ≥ 5.5 mmol/L: pooled analysis from two phase 3 trials.
BackgroundReliable, timely-onset, oral treatments with an acceptable safety profile for patients with hyperkalemia are needed. We examined the efficacy and safety of sodium zirconium cyclosilicate (SZC; formerly ZS-9) treatment for ≤ 48 h in patients with baseline serum potassium level ≥ 5.5 mmol/L.MethodsData were pooled from two phase 3 studies (ZS-003 and HARMONIZE) among patients receiving SZC 10 g three times daily. Outcomes included mean and absolute change from baseline, median time to potassium level ≤ 5.5 and ≤ 5.0 mmol/L, and proportion achieving potassium level ≤ 5.5 and ≤ 5.0 mmol/L at 4, 24, and 48 h. Outcomes were stratified by baseline potassium. Safety outcomes were evaluated.ResultsAt baseline, 125 of 170 patients (73.5%) had potassium level 5.5-< 6.0, 39 (22.9%) had potassium level 6.0-6.5, and 6 (3.5%) had potassium level > 6.5 mmol/L. Regardless of baseline potassium, mean potassium decreased at 1 h post-initial dose. By 4 and 48 h, 37.5% and 85.0% of patients achieved potassium level ≤ 5.0 mmol/L, respectively. Median (95% confidence interval) times to potassium level ≤ 5.5 and ≤ 5.0 mmol/L were 2.0 (1.1-2.0) and 21.6 (4.1-22.4) h, respectively. Fifteen patients (8.8%) experienced adverse events; none were serious.ConclusionsSZC 10 g three times daily achieved serum potassium reduction and normokalemia, with a favorable safety profile.Trial registrationClinicalTrials.gov identifiers: ZS-003: NCT01737697 and HARMONIZE: NCT02088073
Occurrence of arsenite in surface and groundwater associated with a perennial stream located in Western Nebraska, USA
Dissolved arsenic typically results from chemical weathering of arsenic rich sediments and is most often found in oxidized forms in surface water. The mobility of arsenic is controlled by its valence state and also by its association with iron oxides minerals, the forms of which are both influenced by abiotic and biotic processes in aqueous environment. In this study, speciation methods were used to measure and confirm the presence of reduced arsenic species in the surface water of Frenchman creek, a gaining stream that crosses the Colorado- Nebraska border. Selective extraction analysis of aquifer and stream bed sediments shows that the bulk of the arsenic occurs with labile iron-rich oxy(hydroxide) minerals. Total dissolved arsenic in surface and groundwater ranged from ~3–18 μg L–1, and reduced arsenic species comprise about 41% of the total dissolved arsenic (16.0 μg L–1) in Frenchman creek. Leachable arsenic in the aquifer sediment samples ranged up to 1553 μg kg–1, while samples from Frenchman creek bed sediments contained 4218 μg kg–1. Dynamic surface and groundwater interaction sustains arsenite in iron-rich surface headwaters, and the implied toxicity of reduced arsenic in this hydrogeological setting, which can be important in surface water environments around the globe
Detection and quantification of oil under sea ice : the view from below
© The Author(s), 2014. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Cold Regions Science and Technology 109 (2015): 9-17, doi:10.1016/j.coldregions.2014.08.004.Traditional measures for detecting oil spills in the open-ocean are both difficult to apply and less effective in ice-covered seas. In view of the increasing levels of commercial activity in the Arctic, there is a growing gap between the potential need to respond to an oil spill in Arctic ice-covered waters and the capability to do so. In particular, there is no robust operational capability to remotely locate oil spilt under or encapsulated within sea ice. To date, most research approaches the problem from on or above the sea ice, and thus they suffer from the need to ‘see’ through the ice and overlying snow. Here we present results from a large-scale tank experiment which demonstrate the detection of oil beneath sea ice, and the quantification of the oil layer thickness is achievable through the combined use of an upward-looking camera and sonar deployed in the water column below a covering of sea ice. This approach using acoustic and visible measurements from below is simple and effective, and potentially transformative with respect to the operational response to oil spills in the Arctic marine environment. These results open up a new direction of research into oil detection in ice-covered seas, as well as describing a new and important role for underwater vehicles as platforms for oil-detecting sensors under Arctic sea ice.This work was funded through a competitive grant for the detection of oil under ice obtained from Prince William Sound Oil Spill Recovery Institute (OSRI) (11-10-09). Additional funding/resources was obtained through the EU FP7 funded ACCESS programme (Grant Agreement n°. 265863)
Nanoengineered Materials for SWIR HOT Detectors
Heavy metal Selenide has been investigated for more than half century for high operating temperature (HOT) mid wave infrared (MWIR) applications. Most of the efforts have been devoted to make detector arrays on high-resistivity Si substrates for operating wavelengths in the 1.5 to 5.0 m region using physical vapor transport grown poly crystalline materials. For most of the biological spectral and imaging applications, short wave infrared (SWIR) detectors have shown better performance. Recent growth materials have shown variation in morphology with slight change in growth conditions and hence variation in performance parameters such as bandgap, mobility and resistivity from sample to sample. We have performed growth and optical characterization of pure and doped PbS and PbSe and have determined bandgap using available theoretical models for different morphologies
Design of Materials for IR Detectors Using High Z Elements for High Energy Radiation Environment
There is a strong need for rad hard and high operating temperature IR detectors for space environment. Heavy metal Selenides (high Z and large density) have been investigated for more than half century for high operating temperature mid wave infrared (MWIR) applications. Most of the efforts have been devoted to make detector arrays on high-resistivity Si substrates for operating wavelengths in the 1.5 to 5.0 m region using physical vapor transport grown poly crystalline materials. For most of the biological spectral and imaging applications, short wave infrared (SWIR) detectors have shown better performance. Recent growth materials have shown variation in morphology with slight change in growth conditions and hence variation in performance parameters such as bandgap, mobility and resistivity from sample to sample. We have performed growth and optical characterization of binary materials CdSe-PbSe to determine the suitability for IR detector. We have determined bandgap using several theoretical models for different morphologies observed during growth on silicon wafers
Plexin D1 determines body fat distribution by regulating the type V collagen microenvironment in visceral adipose tissue
Proceedings of the National Academy of Sciences of the United States of America112144363-436
Built-in and induced polarization across LaAlO/SrTiO heterojunctions
Ionic crystals terminated at oppositely charged polar surfaces are inherently
unstable and expected to undergo surface reconstructions to maintain
electrostatic stability. Essentially, an electric field that arises between
oppositely charged atomic planes gives rise to a built-in potential that
diverges with thickness. In ultra thin film form however the polar crystals are
expected to remain stable without necessitating surface reconstructions, yet
the built-in potential has eluded observation. Here we present evidence of a
built-in potential across polar \lao ~thin films grown on \sto ~substrates, a
system well known for the electron gas that forms at the interface. By
performing electron tunneling measurements between the electron gas and a
metallic gate on \lao ~we measure a built-in electric field across \lao ~of 93
meV/\AA. Additionally, capacitance measurements reveal the presence of an
induced dipole moment near the interface in \sto, illuminating a unique
property of \sto ~substrates. We forsee use of the ionic built-in potential as
an additional tuning parameter in both existing and novel device architectures,
especially as atomic control of oxide interfaces gains widespread momentum.Comment: 6 pages, 4 figures. Submitted to Nature physics on May 1st, 201
- …