141 research outputs found
Disorder-dependent Li diffusion in investigated by machine learning potential
Solid-state electrolytes with argyrodite structures, such as
, have attracted considerable attention due to their
superior safety compared to liquid electrolytes and higher ionic conductivity
than other solid electrolytes. Although experimental efforts have been made to
enhance conductivity by controlling the degree of disorder, the underlying
diffusion mechanism is not yet fully understood. Moreover, existing theoretical
analyses based on ab initio MD simulations have limitations in addressing
various types of disorder at room temperature. In this study, we directly
investigate Li-ion diffusion in at 300 K using
large-scale, long-term MD simulations empowered by machine learning potentials
(MLPs). To ensure the convergence of conductivity values within an error range
of 10%, we employ a 25 ns simulation using a supercell
containing 6500 atoms. The computed Li-ion conductivity, activation energies,
and equilibrium site occupancies align well with experimental observations.
Notably, Li-ion conductivity peaks when Cl ions occupy 25% of the 4c sites,
rather than at 50% where the disorder is maximized. This phenomenon is
explained by the interplay between inter-cage and intra-cage jumps. By
elucidating the key factors affecting Li-ion diffusion in
, this work paves the way for optimizing ionic
conductivity in the argyrodite family.Comment: 34 pages, 6 figure
CVD-grown monolayer MoS2 in bioabsorbable electronics and biosensors
Transient electronics entails the capability of electronic components to dissolve or reabsorb in a controlled manner when used in biomedical implants. Here, the authors perform a systematic study of the processes of hydrolysis, bioabsorption, cytotoxicity and immunological biocompatibility of monolayer MoS2
Analyzing the advantages of subcutaneous over transcutaneous electrical stimulation for activating brainwaves
Transcranial electrical stimulation (TES) is a widely accepted neuromodulation modality for treating brain disorders. However, its clinical efficacy is fundamentally limited due to the current shunting effect of the scalp and safety issues. A newer electrical stimulation technique called subcutaneous electrical stimulation (SES) promises to overcome the limitations of TES by applying currents directly at the site of the disorder through the skull. While SES seems promising, the electrophysiological effect of SES compared to TES is still unknown, thus limiting its broader application. Here we comprehensively analyze the SES and TES to demonstrate the effectiveness and advantages of SES. Beagles were bilaterally implanted with subdural strips for intracranial electroencephalography and electric field recording. For the intracerebral electric field prediction, we designed a 3D electromagnetic simulation framework and simulated TES and SES. In the beagle model, SES induces three to four-fold larger cerebral electric fields compared to TES, and significant changes in power ratio of brainwaves were observed only in SES. Our prediction framework suggests that the field penetration of SES would be several-fold larger than TES in human brains. These results demonstrate that the SES would significantly enhance the neuromodulatory effects compared to conventional TES and overcome the TES limitations.11Ysciescopu
Dissipation patterns of acrinathrin and metaflumizone in Aster scaber
Abstract
The establishment of preharvest residue limits (PHRLs) is important to minimize damage to producer and consumers caused by agricultural products which pesticide residue exceeds maximum residue limits (MRLs). Dissipation patterns of acrinathrin and metaflumizone in Aster scaber in greenhouse were studied during 10days in order to determine a pre-harvest interval after application. Acrinathrin and metaflumizone were applied in two different greenhouse, located in Taean-gun (field 1) and Gwangyang-si (field 2). Samples were collected at 0, 1, 2, 3, 5, 7, and 10days after insecticides application. The recoveries of two insecticides analyzed by LC–MS/MS and HPLC–DAD were ranged from 77.1 to 111.3%. The half-lives of acrinathrin and metaflumizone residues respectively were 3.8 and 5.9days in field 1 and 9.2 and 4.5days in field 2. The PHRLs 10days before harvesting A. scaber were 0.610mg/kg (field 1), 0.946mg/kg (field 2) for acrinathrin, and 5.930mg/kg (field 1), 5.147mg/kg (field 2) for metaflumizone. This results can be used as basic data for the establishment of PHRL in A. scaber
An Efficient Noninvasive Neuromodulation Modality for Overactive Bladder Using Time Interfering Current Method
Objective: The present study aimed to evaluate a new tibial nerve stimulation (TNS) modality, which uses interferential currents, in terms of the stimulation electric field penetration efficiency into the body and physiological effectiveness. Methods: In silico experiments were performed to analyze the penetration efficiency of proposed interferential current therapy (ICT). Based on this, we performed in vivo experiments to measure excitation threshold of ICT for the tibial nerve, which is related to stimulation field near the nerve. Regarding analysis of the physiological effectiveness, in vivo ICT-TNS was performed, and changes in bladder contraction frequency and voiding volume were measured. The penetration efficiency and physiological effectiveness of ICT were evaluated by comparison with those of conventional TNS using transcutaneous electrical nerve stimulation (TENS). Results: Simulation results showed that ICT has high penetration efficiency, thereby generating stronger field than TENS. These results are consistent with the in vivo results that nerve excitation threshold of ICT is lower than that of TENS. Moreover, ICT-TNS decreased contraction frequency and increased voiding volume, and its performance was profound compared with that of TENS-TNS. Conclusion: The proposed ICT is more efficient in inducing the stimulation field near the tibial nerve placed deep inside the body compared with conventional TENS and shows a good clinical effectiveness for TNS. Significance: The high efficiency of ICT increases the safety of noninvasive neurostimulation; therefore, it has clinical potential to become a promising modality for TNS to treat OAB and other peripheral neurostimulations.11Nsciescopu
Assembling Inorganic Nanocrystal Gels
Inorganic nanocrystal gels retain distinct properties of individual nanocrystals while offering tunable, network structure-dependent characteristics. We review different mechanisms for assembling gels from colloidal nanocrystals including (1) controlled destabilization, (2) direct bridging, (3) depletion, as well as linking mediated by (4) coordination bonding or (5) dynamic covalent bonding, and we highlight how each impacts gel properties. These approaches use nanocrystal surface chemistry or the addition of small molecules to mediate inter-nanocrystal attractions. Each method offers advantages in terms of gel stability, reversibility, or tunability and presents new opportunities for design of reconfigurable materials and fueled assemblies.This work was primarily supported by the National Science Foundation through the Center
for Dynamics and Control of Materials: an NSF Materials Research Science and Engineering
Center (NSF MRSEC) under Cooperative Agreement DMR-1720595. This work was also
supported by the Welch Foundation (F-1848 and F-1696). E.V.A. acknowledges support
from the Welch Regents Chair (F-0046).Center for Dynamics and Control of Material
The assessment of efficacy of porcine reproductive respiratory syndrome virus inactivated vaccine based on the viral quantity and inactivation methods
<p>Abstract</p> <p>Background</p> <p>There have been many efforts to develop efficient vaccines for the control of porcine reproductive and respiratory syndrome virus (PRRSV). Although inactivated PRRSV vaccines are preferred for their safety, they are weak at inducing humoral immune responses and controlling field PRRSV infection, especially when heterologous viruses are involved.</p> <p>Results</p> <p>In all groups, the sample to positive (S/P) ratio of IDEXX ELISA and the virus neutralization (VN) titer remained negative until challenge. While viremia did not reduce in the vaccinated groups, the IDEXX-ELISA-specific immunoglobulin G increased more rapidly and to significantly greater levels 7 days after the challenge in all the vaccinated groups compared to the non-vaccinated groups (<it>p </it>< 0.05). VN titer was significantly different in the 10<sup>6 </sup>PFU/mL PRRSV vaccine-inoculated and binary ethylenimine (BEI)-inactivated groups 22 days after challenge (<it>p </it>< 0.05). Consequently, the inactivated vaccines tested in this study provided weak memory responses with sequential challenge without any obvious active immune responses in the vaccinated pigs.</p> <p>Conclusions</p> <p>The inactivated vaccine failed to show the humoral immunity, but it showed different immune response after the challenge compared to mock group. Although the 10<sup>6 </sup>PFU/mL-vaccinated and BEI-inactivated groups showed significantly greater VN titers 22 days after challenge, all the groups were already negative for viremia.</p
Colorimetric quantification of linking in thermoreversible nanocrystal gel assemblies
Nanocrystal gels can be responsive, tunable materials, but designing their structure and properties is challenging.
By using reversibly bonded molecular linkers, gelation can be realized under conditions predicted by thermody-
namics. However, simulations have offered the only microscopic insights, with no experimental means to monitor
linking leading to gelation. We introduce a metal coordination linkage with a distinct optical signature allowing
us to quantify linking in situ and establish structural and thermodynamic bases for assembly. Because of coupling
between linked indium tin oxide nanocrystals, their infrared absorption shifts abruptly at a chemically tunable
gelation temperature. We quantify bonding spectroscopically and use molecular simulation to understand
temperature-dependent bonding motifs, revealing that gel formation is governed by reaching a critical number of
effective links that extend the nanocrystal network. Microscopic insights from our colorimetric linking chemistry
enable switchable gels based on thermodynamic principles, opening the door to rational design of programmable
nanocrystal networks.We would like to thank the University of Texas at Austin Mass Spectrometry and NMR Facility
for the use of the Bruker AVANCE III 500: NIH grant number 1 S10 OD021508-01 and the Texas
Materials Institute for the use of the SAXSLAB Ganesha, acquired using an NSF MRI grant
CBET-1624659. We thank the Texas Advanced Computing Center (TACC) at the University
of Texas at Austin for HPC resources. Funding: This research was primarily supported by the
National Science Foundation through the Center for Dynamics and Control of Materials: an
NSF Materials Research Science and Engineering Center (NSF MRSEC) under Cooperative
Agreement DMR-1720595. E.V.A. acknowledges support from the Welch Regents Chair
(F-0046). D.J.M. and T.M.T. also acknowledge support by the Welch Foundation (F-1696
and F-1848). This work was also supported by an NSF Graduate Research Fellowships
(DGE-1610403) to S.A.V. and Arnold O. Beckman Postdoctoral Fellowship to Z.M.S.Center for Dynamics and Control of Material
Recommended from our members
Modular mixing in plasmonic metal oxide nanocrystal gels with thermoreversible links
Gelation offers a powerful strategy to assemble plasmonic nanocrystal networks incorporating both the distinctive optical properties of con-
stituent building blocks and customizable collective properties. Beyond what a single-component assembly can offer, the characteristics of
nanocrystal networks can be tuned in a broader range when two or more components are intimately combined. Here, we demonstrate
mixed nanocrystal gel networks using thermoresponsive metal–terpyridine links that enable rapid gel assembly and disassembly with ther-
mal cycling. Plasmonic indium oxide nanocrystals with different sizes, doping concentrations, and shapes are reliably intermixed in linked
gel assemblies, exhibiting collective infrared absorption that reflects the contributions of each component while also deviating systematically
from a linear combination of the spectra for single-component gels. We extend a many-bodied, mutual polarization method to simulate the
optical response of mixed nanocrystal gels, reproducing the experimental trends with no free parameters and revealing that spectral devia-
tions originate from cross-coupling between nanocrystals with distinct plasmonic properties. Our thermoreversible linking strategy directs
the assembly of mixed nanocrystal gels with continuously tunable far- and near-field optical properties that are distinct from those of the
building blocks or mixed close-packed structures.This research was primarily supported by the National Science
Foundation through the Center for Dynamics and Control of Mate-
rials: an NSF MRSEC under Cooperative Agreement No. DMR-
1720595, with additional support from an Arnold O. Beckman
Postdoctoral Fellowship (Z.M.S.) and the Welch Foundation (Grant
Nos. F-1696 and F-1848). E.V.A. acknowledges support from the
Welch Regents Chair (No. F-0046). We acknowledge the Texas
Advanced Computing Center (TACC) at the University of Texas at
Austin for providing HPC resources.Center for Dynamics and Control of Material
Nanoporous Silicified Phospholipids and Application to Controlled Glycolic Acid Release
This work demonstrates the synthesis and characterization of novel nanoporous silicified phospholipid bilayers assembled inorganic powders. The materials are obtained by silicification process with silica precursor at the hydrophilic region of phospholipid bilayers. This process involves the co-assembly of a chemically active phospholipids bilayer within the ordered porosity of a silica matrix and holds promise as a novel application for controlled drug release or drug containers with a high level of specificity and throughput. The controlled release application of the synthesized materials was achieved to glycolic acid, and obtained a zero-order release pattern due to the nanoporosity
- …