70 research outputs found
Spontaneous Self-Assembly of Silver Nanoparticles into Lamellar Structured Silver Nanoleaves
Uniform lamellar silver nanoleaves (AgNLs) were spontaneously assembled from 4 nm silver nanoparticles (AgNPs) with <i>p</i>-aminothiophenol (PATP) as mediator under mild shaking at room temperature. The compositions of the AgNLs were verified to be âź1 nm Ag<sub>25</sub> nanoclusters and PATP molecules in quinonoid model. The underlying assembly mechanism was systematically investigated and a two-step reaction process was proposed. First, the 4 nm AgNPs were quickly etched to âź1 nm Ag<sub>25</sub> nanoclusters by PATP in the form of [Ag<sub>25</sub>(PATP)<sub><i>n</i></sub>]<sup><i>n</i>+</sup> (<i>n</i> < 12), which were then further electrostatically or covalently interconnected by PATP to form the repeated unit cells of [Ag<sub>25</sub>(PATP)<sub><i>n</i>â1</sub>]<sup>(<i>n</i>â1)+</sup>âPATPâ[Ag<sub>25</sub>(PATP)<sub><i>n</i>â1</sub>]<sup>(<i>n</i>â1)+</sup> (abbreviated as Ag<sub>25</sub>âPATPâAg<sub>25</sub>). Second, these Ag<sub>25</sub>âPATPâAg<sub>25</sub> complexes were employed as building blocks to construct lamellar AgNLs under the directions of the strong dipoleâdipole interaction and the ĎâĎ stacking force between the neighboring benzene rings of PATP. Different reaction parameters including the types and concentrations of ligands, solvents, reaction temperature, ionic strength, and pH, <i>etc</i>., were carefully studied to confirm this mechanism. Finally, the preliminary investigations of the applications for AgNLs as âmolecular junctionsâ and SERS properties were demonstrated. We expect that this convenient and simple method can be in principle extended to other systems, or even mixture system with different types of NPs, and will provide an important avenue for designing metamaterials and exploring their physicochemical properties
Large-Scale Synthesis of Single Crystalline CuSb(S<sub><i>x</i></sub>Se<sub>1â<i>x</i></sub>)<sub>2</sub> Nanosheets with Tunable Composition
Alloying
nanocrystals with multicomponent has been an effective
way to tune the band gap of semiconductor nanocrystals, which promises
their wide applications in optoelectronics, photovoltaics, etc. However,
colloidal synthesis of homogeneous phase multicomponent nanocrystals
in a large scale remains great challenge. Here, we declare the successful
preparation of single-crystalline quaternary CuSbÂ(S<sub><i>x</i></sub>Se<sub>1â<i>x</i></sub>)<sub>2</sub> nanosheets
in a facile one-pot reaction with yield >3 g. The molar ratio of
S/(S
+ Se) in CuSbÂ(S<sub><i>x</i></sub>Se<sub>1â<i>x</i></sub>)<sub>2</sub> could be easily tuned from 1.5% to
13.7% by increasing the reaction temperature which enhances the reactivity
of S source in the reaction, and accordingly, the band gap of the
obtained CuSbÂ(S<sub><i>x</i></sub>Se<sub>1â<i>x</i></sub>)<sub>2</sub> varies from 0.9 to 1.1 eV
Synthesis of ÎąâTrifluoromethyl Ketones via the Cu-Catalyzed Trifluoromethylation of Silyl Enol Ethers Using an Electrophilic Trifluoromethylating Agent
A method has been developed for the
synthesis of Îą-trifluoromethyl
ketones via the Cu-catalyzed trifluoromethylation of silyl enol ethers
with an electrophilic trifluoromethylating agent, which produces a
trifluoromethyl radical
Two-Dimensional Asymmetric Multiferroics: Unique Way toward Strong Magnetoelectric Coupling and Multistate Memory
Two-dimensional
(2D) materials have provided a fascinating platform
for exploring novel multiferroics and emergent magnetoelectric coupling
mechanisms. Here, a novel 2D asymmetric multiferroic based on Janus
2D multiferroic MXene-analogous oxynitrides (InTlNO2) is
presented by using first-principles calculations. We find three inequivalent
phases for InTlNO2, including two metallic phases (p1 and
p2) and one semiconducting phase (p3) with a band gap of 0.88 eV.
All phases are room-temperature multiferroics with different Curie
temperatures, leading to tunability by phase transitions. We show
that there is a 90° rotation of the magnetic anisotropy easy
axis between p1 and p2, where p1 favors the in-plane and p2 the out-of-plane
easy axis. Therefore, the magnetic anisotropy can be tuned by reversing
the out-of-plane polarization. Our strategy provides a unique way
toward strong magnetoelectric coupling and multistate memory
Two-Dimensional Asymmetric Multiferroics: Unique Way toward Strong Magnetoelectric Coupling and Multistate Memory
Two-dimensional
(2D) materials have provided a fascinating platform
for exploring novel multiferroics and emergent magnetoelectric coupling
mechanisms. Here, a novel 2D asymmetric multiferroic based on Janus
2D multiferroic MXene-analogous oxynitrides (InTlNO2) is
presented by using first-principles calculations. We find three inequivalent
phases for InTlNO2, including two metallic phases (p1 and
p2) and one semiconducting phase (p3) with a band gap of 0.88 eV.
All phases are room-temperature multiferroics with different Curie
temperatures, leading to tunability by phase transitions. We show
that there is a 90° rotation of the magnetic anisotropy easy
axis between p1 and p2, where p1 favors the in-plane and p2 the out-of-plane
easy axis. Therefore, the magnetic anisotropy can be tuned by reversing
the out-of-plane polarization. Our strategy provides a unique way
toward strong magnetoelectric coupling and multistate memory
Fast and In-Depth Reconstruction of Two-Dimension Cobalt-Based Zeolitic Imidazolate Framework in Glucose Oxidation Processes
Currently,
metalâorganic frameworks (MOFs) have emerged
as viable candidates for enduring electrode materials in nonenzyme
glucose sensing. However, given the inherent water susceptibility
of MOFs and their complete self-reconstruction during the process
of electrochemical oxygen evolution in alkaline conditions, we are
motivated to explore the truth of MOFs catalyzing glucose oxidation.
In this work, we fabricated a two-dimensional cobalt-based zeolitic
imidazolate framework (ZIF-L) as the electrode material for catalyzing
glucose oxidation in alkaline conditions. Our explorations revealed
that while the initial glucose catalytic response varied among ZIF-L
samples with differing thicknesses, the ultimate steady-state catalytic
performance remained largely consistent. This phenomenon arose from
the transformation of ZIF-L with distinct thicknesses into CoOOH with
uniform morphological and structural characteristics during the glucose
catalysis process. And in situ Raman spectroscopy elucidated the sustained
equilibrium within the glucose catalytic system, wherein the dynamic
interconversion between CoOOH and Co(OH)2 governs the overall
process. This study contributes to an enhanced understanding of the
glucose catalytic mechanism aspects of nonenzymatic glucose sensor
electrode materials, offering insights that serve as inspiration for
the development of advanced glucose electrode materials
Regulation of Monocarboxylic Acid Transporter-1 by cAMP Dependent Vesicular Trafficking in Brain Microvascular Endothelial Cells
<div><p>In this study, a detailed characterization of Monocarboxylic Acid Transporter-1 (Mct1) in cytoplasmic vesicles of cultured rat brain microvascular endothelial cells shows them to be a diverse population of endosomes intrinsic to the regulation of the transporter by a brief 25 to 30 minute exposure to the membrane permeant cAMP analog, 8Br-cAMP. The vesicles are heterogeneous in size, mobility, internal pH, and co-localize with discreet markers of particular types of endosomes including early endosomes, clathrin coated vesicles, caveolar vesicles, trans-golgi, and lysosomes. The vesicular localization of Mct1 was not dependent on its N or C termini, however, the size and pH of Mct1 vesicles was increased by deletion of either terminus demonstrating a role for the termini in vesicular trafficking of Mct1. Using a novel BCECF-AM based assay developed in this study, 8Br-cAMP was shown to decrease the pH of Mct1 vesicles after 25 minutes. This result and method were confirmed in experiments with a ratiometric pH-sensitive EGFP-mCherry dual tagged Mct1 construct. Overall, the results indicate that cAMP signaling reduces the functionality of Mct1 in cerebrovascular endothelial cells by facilitating its entry into a highly dynamic vesicular trafficking pathway that appears to lead to the transporter's trafficking to autophagosomes and lysosomes.</p></div
The Efficacy and Safety of Different Kinds of Laparoscopic Cholecystectomy: A Network Meta Analysis of 43 Randomized Controlled Trials
<div><p>Background and Objective</p><p>We conducted a network meta analysis (NMA) to compare different kinds of laparoscopic cholecystectomy [LC] (single port [SPLC], two ports [2PLC], three ports [3PLC], and four ports laparoscopic cholecystectomy [4PLC], and four ports mini-laparoscopic cholecystectomy [mini-4PLC]).</p><p>Methods</p><p>PubMed, the Cochrane library, EMBASE, and ISI Web of Knowledge were searched to find randomized controlled trials [RCTs]. Direct pair-wise meta analysis (DMA), indirect treatment comparison meta analysis (ITC) and NMA were conducted to compare different kinds of LC.</p><p>Results</p><p>We included 43 RCTs. The risk of bias of included studies was high. DMA showed that SPLC was associated with more postoperative complications, longer operative time, and higher cosmetic score than 4PLC, longer operative time and higher cosmetic score than 3PLC, more postoperative complications than mini-4PLC. Mini-4PLC was associated with longer operative time than 4PLC. ITC showed that 3PLC was associated with shorter operative time than mini-4PLC, and lower postoperative pain level than 2PLC. 2PLC was associated with fewer postoperative complications and longer hospital stay than SPLC. NMA showed that SPLC was associated with more postoperative complications than mini-4PLC, and longer operative time than 4PLC.</p><p>Conclusion</p><p>The rank probability plot suggested 4PLC might be the worst due to the highest level of postoperative pain, longest hospital stay, and lowest level of cosmetic score. The best one might be mini-4PLC because of highest level of cosmetic score, and fewest postoperative complications, or SPLC because of lowest level of postoperative pain and shortest hospital stay. But more studies are needed to determine which will be better between mini-4PLC and SPLC.</p></div
Mct1 is apparent in cytoplasmic vesicles.
<p>RBE4 cells expressing mCherry-Mct1 were imaged live using confocal microscopy (<b>A</b>). In the last three micrographs, RBE4 cells were immunostained with an anti-Mct1 antibody, fixed in 3.7% formaldehyde, and permeabilized with either methanol and acetone (<b>B</b>), or 0.5% TritonX-100 (<b>C</b>), or 5% glacial acetic acid (<b>D</b>). Scaleâ=â5 ÂľM.</p
Fast and In-Depth Reconstruction of Two-Dimension Cobalt-Based Zeolitic Imidazolate Framework in Glucose Oxidation Processes
Currently,
metalâorganic frameworks (MOFs) have emerged
as viable candidates for enduring electrode materials in nonenzyme
glucose sensing. However, given the inherent water susceptibility
of MOFs and their complete self-reconstruction during the process
of electrochemical oxygen evolution in alkaline conditions, we are
motivated to explore the truth of MOFs catalyzing glucose oxidation.
In this work, we fabricated a two-dimensional cobalt-based zeolitic
imidazolate framework (ZIF-L) as the electrode material for catalyzing
glucose oxidation in alkaline conditions. Our explorations revealed
that while the initial glucose catalytic response varied among ZIF-L
samples with differing thicknesses, the ultimate steady-state catalytic
performance remained largely consistent. This phenomenon arose from
the transformation of ZIF-L with distinct thicknesses into CoOOH with
uniform morphological and structural characteristics during the glucose
catalysis process. And in situ Raman spectroscopy elucidated the sustained
equilibrium within the glucose catalytic system, wherein the dynamic
interconversion between CoOOH and Co(OH)2 governs the overall
process. This study contributes to an enhanced understanding of the
glucose catalytic mechanism aspects of nonenzymatic glucose sensor
electrode materials, offering insights that serve as inspiration for
the development of advanced glucose electrode materials
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