keyword
MENU ▼
Read by QxMD icon Read
search

Volume kinetics

keyword
https://www.readbyqxmd.com/read/28722041/ultrafast-dynamics-and-solvent-dependent-deactivation-kinetics-of-bodipy-molecular-rotors
#1
Tomislav Suhina, Saeed Amirjalayer, Sander Woutersen, Daniel Bonn, Albert M Brouwer
Molecular rotors based on meso-substituted boron-dipyrromethane (BODIPY) are widely recognized fluorescent viscosity sensors. The viscosity dependence of their fluorescence arises from an efficient excited-state deactivation process that can only occur when molecular-scale motion is not hindered. Here, we use visible and IR pump-probe spectroscopies combined with TD-DFT calculations to show that this fluorescence deactivation takes place through a fast and irreversible process which does not involve intermediate electronic states...
July 19, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28720536/a-diffusing-wave-spectroscopy-study-of-pharmaceutical-emulsions-for-physical-stability-assessment
#2
Andreas Niederquell, Alexandra H E Machado, Martin Kuentz
Emulsions are broadly used in pharmaceutics either as intermediate products or as final dosage forms. Such disperse systems are only kinetically stabilized and therefore early detection of physical instability is highly desirable. This work employed diffusing wave spectroscopy (DWS) to study a series of model emulsions that were categorized, based on their composition, as either "simple" or "complex". DWS data were compared with results of droplet size imaging, apparent viscosity obtained by microfluidics, and near-infrared (NIR) analytical centrifugation...
July 15, 2017: International Journal of Pharmaceutics
https://www.readbyqxmd.com/read/28718630/designed-formulation-of-se-impregnated-nitrogen-containing-hollow-core-mesoporous-shell-carbon-spheres-multifunctional-potential-cathode-for-li-se-and-na-se-batteries
#3
Balakumar Kalimuthu, Kalaiselvi Nallathamby
Nitrogen containing carbon spheres with hollow core and mesoporous shell (NHCS), capable of confining Se as high as 72 wt.% has been demonstrated to exhibit appreciable electrochemical behaviour with 52 and 61 wt.% Se loading. In particular, 52 wt.% Se confined NHCS cathode exhibits 265 mAh/g at 10C rate and retains 75% of initial capacity at 2C rate up to 10000 cycles with an insignificant decay of 0.0025% per cycle, which is an ever first report on the extended cycle life of Li-Se batteries. Due to the negligible difference found between the transport kinetics of Se and that of Li2Se, irrespective of the cycling rate, 52 wt...
July 18, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28711193/nociceptin-receptors-in-alcohol-use-disorders-a%C3%A2-positron-emission-tomography-study-using-11-c-nop-1a
#4
Rajesh Narendran, Roberto Ciccocioppo, Brian Lopresti, Jennifer Paris, Michael L Himes, N Scott Mason
BACKGROUND: The neuropeptide transmitter nociceptin, which binds to the nociceptin/orphanin FQ peptide (NOP) receptor, is a core component of the brain's antistress system. Nociceptin exerts its antistress effect by counteracting the functions of corticotropin-releasing factor, the primary stress-mediating neuropeptide in the brain. Basic investigations support a role for medications that target nociceptin receptors in the treatment of alcohol use disorders. Thus, it is of high interest to measure the in vivo status of NOP receptors in individuals with alcohol use disorders...
May 31, 2017: Biological Psychiatry
https://www.readbyqxmd.com/read/28709938/a-cross-sectional-comparison-of-brain-glucose-and-ketone-metabolism-in-cognitively-healthy-older-adults-mild-cognitive-impairment-and-early-alzheimer-s-disease
#5
E Croteau, C A Castellano, M Fortier, C Bocti, T Fulop, N Paquet, S C Cunnane
INTRODUCTION: Deteriorating brain glucose metabolism precedes the clinical onset of Alzheimer's disease (AD) and appears to contribute to its etiology. Ketone bodies, mainly β-hydroxybutyrate and acetoacetate, are the primary alternative brain fuel to glucose. Some reports suggest that brain ketone metabolism is unchanged in AD but, to our knowledge, no such data are available for MCI. OBJECTIVE: To compare brain energy metabolism (glucose and acetoacetate) and some brain morphological characteristics in cognitively healthy older adult controls (CTL), mild cognitive impairment (MCI) and early AD...
July 11, 2017: Experimental Gerontology
https://www.readbyqxmd.com/read/28709105/fundamental-mechanisms-and-reactions-in-non-catalytic-subcritical-hydrothermal-processes-a-review
#6
REVIEW
Azadeh Yousefifar, Saeid Baroutian, Mohammed M Farid, Daniel J Gapes, Brent R Young
The management and disposal of solid waste is of increasing concern across the globe. Hydrothermal processing of sludge has been suggested as a promising solution to deal with the considerable amounts of sludge produced worldwide. Such a process not only degrades organic compounds and reduces waste volume, but also provides an opportunity to recover valuable substances. Hydrothermal processing comprises two main sub-processes: wet oxidation (WO) and thermal hydrolysis (TH), in which the formation of various free radicals results in the production of different intermediates...
June 30, 2017: Water Research
https://www.readbyqxmd.com/read/28708734/t2-correction-in-dynamic-contrast-enhanced-magnetic-resonance-imaging-of-glioblastoma-from-a-half-dose-of-high-relaxivity-contrast-agent
#7
Silvano Filice, Girolamo Crisi, Gunter Erb
OBJECTIVE: The aim of this study was to evaluate the arterial input function (AIF) and tissue enhancement time curve (tissue function [TF]) obtained after the administration of a half-dose gadobenate dimeglumine (0.05-mmol/kg body weight [bw]) compared with a full dose (0.1-mmol/kg bw) of a standard-relaxivity contrast agent. METHODS: We enrolled 40 adult patients with glioblastoma in an interindividual comparative study. Patients were randomized to 1 of the 2 study arms: 20 patients received 0...
July 13, 2017: Journal of Computer Assisted Tomography
https://www.readbyqxmd.com/read/28707900/aerosol-fragmentation-driven-by-coupling-of-acid-base-and-free-radical-chemistry-in-the-heterogeneous-oxidation-of-aqueous-citric-acid-by-oh-radicals
#8
Matthew J Liu, Aaron A Wiegel, Kevin R Wilson, Frances A Houle
A key uncertainty in the heterogeneous oxidation of carboxylic acids by hydroxyl radicals (OH) in aqueous phase aerosol is how the free radical reaction pathways might be altered by acid-base chemistry. In particular, if acid-base reactions occur concurrently with acyloxy radical formation and unimolecular decomposition of alkoxy radicals, there is a possibility that differences in reaction pathways impact the partitioning of organic carbon between the gas and aqueous phases. To examine these questions, a kinetic model is developed for the OH initiated oxidation of citric acid aerosol at high relative humidity...
July 14, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28706264/first-principles-study-of-sodium-intercalation-in-crystalline-na-x-si24-0%C3%A2-%C3%A2-%C3%A2-x%C3%A2-%C3%A2-%C3%A2-4-as-anode-material-for-na-ion-batteries
#9
Unai Arrieta, Nebil A Katcho, Oier Arcelus, Javier Carrasco
The search for Si-based anodes capable of undergoing low volume changes during electrochemical operation in rechargeable batteries is ample and active. Here we focus on crystalline Si24, a recently discovered open-cage allotrope of silicon, to thoroughly investigate its electrochemical performance using density functional theory calculations. In particular, we examine the phase stability of Na x Si24 along the whole composition range (0 ≤ x ≤ 4), volume and voltage changes during the (de)sodiation process, and sodium ion mobility...
July 13, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28699737/extending-the-use-of-highly-porous-and-functionalized-mofs-to-th-iv-capture
#10
Nan Zhang, Li-Yong Yuan, Wen-Lu Guo, Shi-Zhong Luo, Zhi-Fang Chai, Wei-Qun Shi
Thorium separation has recently become a hot topic because of the potential application of thorium as a future nuclear fuel, while metal-organic framework (MOF) materials have received much attention in the separation field due to their unique properties. Herein, a highly porous and stable MOF, UiO-66, and its carboxyl derivatives (UiO-66-COOH and UiO-66-(COOH)2) were synthesized and explored for the first time for Th(IV) capture from a weak acidic solution. Although the introduction of carboxyl groups into UiO-66 leads to an obvious decrease in the surface area and pore volume, the adsorbability toward Th(IV) is greatly enhanced...
July 19, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28697935/continuous-countercurrent-tangential-chromatography-for-mixed-mode-post-capture-operations-in-monoclonal-antibody-purification
#11
Amit K Dutta, Dmitriy Fedorenko, Jasmine Tan, Joseph A Costanzo, David S Kahn, Andrew L Zydney, Oleg Shinkazh
Continuous Countercurrent Tangential Chromatography (CCTC) has been shown to demonstrate significant advantages over column chromatography including higher productivity, lower operational pressure, disposable flow path, and lower resin use. Previous applications of CCTC have been limited to initial capture of monoclonal antibodies (mAb) from clarified cell culture harvest. In this present article, a CCTC system was designed and tested for a post-capture antibody purification step. Mixed mode cation exchange-hydrophobic interaction chromatography resins with two different particle sizes were used to reduce host cell protein (HCP), leached protein A, DNA, and aggregates from a mAb stream after a protein A operation...
June 22, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28697382/bacterial-mobilization-and-transport-through-manure-enriched-soils-experiment-and-modeling
#12
N Sepehrnia, L Memarianfard, A A Moosavi, J Bachmann, G Guggenberger, F Rezanezhad
A precise evaluation of bacteria transport and mathematical investigations are useful for best management practices in agroecosystems. In this study, using laboratory experiments and modeling approaches, we assess the transport of bacteria released from three types of manure (cow, sheep, and poultry) to find the importance of the common manures in agricultural activities in soil and water pollution. Thirty six intact soil columns with different textures (sandy, loamy, and silty clay loam) were sampled. Fecal coliform leaching from layers of the manures on the soil surface was conducted under steady-state saturated flow conditions at 20 °C for up to four Pore Volumes (PVs)...
July 8, 2017: Journal of Environmental Management
https://www.readbyqxmd.com/read/28689125/removal-of-pharmaceuticals-in-pre-denitrifying-mbbr-influence-of-organic-substrate-availability-in-single-and-three-stage-configurations
#13
Fabio Polesel, Elena Torresi, Luca Loreggian, Mònica Escolà Casas, Magnus Christensson, Kai Bester, Benedek Gy Plósz
Due to the limited efficiency of conventional biological treatment, innovative solutions are being explored to improve the removal of trace organic chemicals in wastewater. Controlling biomass exposure to growth substrate represents an appealing option for process optimization, as substrate availability likely impacts microbial activity, hence organic trace chemical removal. This study investigated the elimination of pharmaceuticals in pre-denitrifying moving bed biofilm reactors (MBBRs), where biofilm exposure to different organic substrate loading and composition was controlled by reactor staging...
June 26, 2017: Water Research
https://www.readbyqxmd.com/read/28688449/efficient-chemical-potential-evaluation-with-kinetic-monte-carlo-method-and-non-uniform-external-potential-lennard-jones-fluid-liquid-and-solid
#14
E A Ustinov
The aim of this paper is to present a method of a direct evaluation of the chemical potential of fluid, liquid, and solid with kinetic Monte Carlo simulation. The method is illustrated with the 12-6 Lennard-Jones (LJ) system over a wide range of density and temperature. A distinctive feature of the methodology used in the present study is imposing an external potential on the elongated simulation box to split the system into two equilibrium phases, one of which is substantially diluted. This technique provides a reliable direct evaluation of the chemical potential of the whole non-uniform system (including that of the uniformly distributed dense phase in the central zone of the box), which, for example, is impossible in simulation of the uniform crystalline phase...
July 7, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28685574/low-cost-and-green-fabrication-of-polymer-electronic-devices-by-push-coating-the-polymer-active-layers
#15
Varun Vohra, Wojciech Mroz, Shusei Inaba, William Porzio, Umberto Giovanella, Francesco Galeotti
Due to both their easy processability and compatibility with roll-to-roll processes, polymer electronics is considered to be the most promising technology for the future generation of low-cost electronic devices such as light-emitting diodes and solar cells. However, the state-of-the-art deposition technique for polymer electronics (spin-coating) generates a high volume of chlorinated solution wastes during the active layer fabrication. Here, we demonstrate that devices with similar or higher performances can be manufactured using the push-coating technique in which a polydimethylsiloxane (PDMS) layer is simply laid over a very small amount of solution (less than 1l/covered cm2) which is then left for drying...
July 7, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28684775/controllable-microfluidic-production-of-drug-loaded-plga-nanoparticles-using-partially-water-miscible-mixed-solvent-microdroplets-as-a-precursor
#16
Jiang Xu, Shusheng Zhang, Anais Machado, Sébastien Lecommandoux, Olivier Sandre, Frank Gu, Annie Colin
We present a versatile continuous microfluidic flow-focusing method for the production of Doxorubicin (DOX) or Tamoxifen (TAM)-loaded poly(D,L-lactic-co-glycolic acid) (PLGA) nanoparticles (NPs). We use a partially water-miscible solvent mixture (dimethyl sulfoxide DMSO+ dichloromethane DCM) as precursor drug/polymer solution for NPs nucleation. We extrude this partially water-miscible solution into an aqueous medium and synthesized uniform PLGA NPs with higher drug loading ability and longer sustained-release ability than conventional microfluidic or batch preparation methods...
July 6, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28684346/antibiotic-loaded-bone-graft-for-reduction-of-surgical-site-infection-in-spinal-fusion
#17
Stefanie M Shiels, Vivek P Raut, Patrick B Patterson, Brian R Barnes, Joseph C Wenke
BACKGROUND CONTEXT: Infections remain a leading complication associated with spinal arthrodesis, regardless of the use of prophylactic antibiotics and improved surgical techniques, with incidence of infection as high as 8.2%. Infection prolongs antibiotic usage, increases hospital time, and inevitably inflates overall treatment costs. Local antibiotics, such as vancomycin, have been used in combination with fusion materials over the past decade to decrease infection risk. An ideal graft material would serve a dual role: encourage vertebral fusion while reducing incidence of infection...
July 3, 2017: Spine Journal: Official Journal of the North American Spine Society
https://www.readbyqxmd.com/read/28681727/carbon-sphere-co9s8-yolk-shell-structure-with-good-morphology-stability-for-improved-lithium-storage-performance
#18
Xuekun Tang, Jing Huang, Qiming Feng, Kun Liu, Xianping Luo, Zishun Li
The poor electronic conductivity and huge volume expansion of cobalt sulfides upon cycling would lead to their poor electrochemical performances for LIBs. Here, we rationally design a yolk-shell carbon sphere@Co9S8 (C@CS) composite, which demonstrates improved kinetics and excellent morphology stability during cycling. This structure can keep Co9S8 shell from collapse and aggregation. After cycling, a layer of thin solid electrolyte interphase (SEI) coated on Co9S8 shell and prevented them from dissolving in electrolyte, which is helpful for the electrochemical performances...
July 6, 2017: Nanotechnology
https://www.readbyqxmd.com/read/28676416/noise-slows-the-rate-of-michaelis-menten-reactions
#19
J David Van Dyken
Microscopic randomness and the small volumes of living cells combine to generate random fluctuations in molecule concentrations called "noise". Here I investigate the effect of noise on biochemical reactions obeying Michaelis-Menten kinetics, concluding that substrate noise causes these reactions to slow. I derive a general expression for the time evolution of the joint probability density of chemical species in arbitrarily connected networks of non-linear chemical reactions in small volumes. This equation is a generalization of the chemical master equation (CME), a common tool for investigating stochastic chemical kinetics, extended to reaction networks occurring in small volumes, such as living cells...
July 1, 2017: Journal of Theoretical Biology
https://www.readbyqxmd.com/read/28674847/a-new-integrated-dual-time-point-amyloid-pet-mri-data-analysis-method
#20
Diego Cecchin, Henryk Barthel, Davide Poggiali, Annachiara Cagnin, Solveig Tiepolt, Pietro Zucchetta, Paolo Turco, Paolo Gallo, Anna Chiara Frigo, Osama Sabri, Franco Bui
PURPOSE: In the initial evaluation of patients with suspected dementia and Alzheimer's disease, there is no consensus on how to perform semiquantification of amyloid in such a way that it: (1) facilitates visual qualitative interpretation, (2) takes the kinetic behaviour of the tracer into consideration particularly with regard to at least partially correcting for blood flow dependence, (3) analyses the amyloid load based on accurate parcellation of cortical and subcortical areas, (4) includes partial volume effect correction (PVEC), (5) includes MRI-derived topographical indexes, (6) enables application to PET/MRI images and PET/CT images with separately acquired MR images, and (7) allows automation...
July 4, 2017: European Journal of Nuclear Medicine and Molecular Imaging
keyword
keyword
40355
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"