16 research outputs found
Pectin Alleviates High Fat (Lard) Diet-Induced Nonalcoholic Fatty Liver Disease in Mice: Possible Role of Short-Chain Fatty Acids and Gut Microbiota Regulated by Pectin
Consumption
of pectin contributes to changes in the gut microbiota
and the metabolism of short-chain fatty acids (SCFAs). We aimed to
investigate the effects of and mechanism by which pectin prevented
nonalcoholic fatty liver disease (NAFLD) in mice that were fed a high-fat
diet containing 30% lard (HF). HF-fed mice that orally ingested pectin
for 8 weeks exhibited improvements in lipid metabolism and decreased
oxidative stress and inflammation through a mechanism regulated by
the mitogen-activated protein kinase pathway. Pectin dose-dependently
generated an increase in acetic acid (from 566.4 ± 26.6 to 694.6
± 35.9 μmol/mL, <i>p</i> < 0.05) and propionic
acid (from 474.1 ± 84.3 to 887.0 ± 184.7 μmol/mL, <i>p</i> < 0.05) contents and significantly increased the relative
abundance of Bacteroides (from 0.27%
to 11.6%), Parabacteroides (from 3.9‰
to 5.3%), Olsenella (from 2.9‰
to 1.3%), and Bifidobacterium (from
0.03% to 1.9%) in the gut of HF-fed mice. Intestinal microbiota and
SCFAs may thus contribute to the well-established link between pectin
consumption and NAFLD
One-Pot Synthesis of Pyrrolo[3,2,1-<i>kl</i>]phenothiazines through Copper-Catalyzed Tandem Coupling/Double Cyclization Reaction
A novel and efficient synthesis of
pyrrolo[3,2,1-<i>kl</i>]phenothiazines has been
developed through a Cu(I)-catalyzed
tandem C–S coupling/double cyclization process. Using 2-alkynyl-6-iodoanilines
and <i>o</i>-bromobenzenethiols as the starting materials,
a wide range of pyrrolo[3,2,1-<i>kl</i>]phenothiazine
derivatives were facilely and efficiently generated in one pot under
Cu(I) catalysis
Physiologically Relevant Changes in Serotonin Resolved by Fast Microdialysis
Online
microdialysis is a sampling and detection method that enables continuous
interrogation of extracellular molecules in freely moving subjects
under behaviorally relevant conditions. A majority of recent publications
using brain microdialysis in rodents report sample collection times
of 20–30 min. These long sampling times are due, in part, to
limitations in the detection sensitivity of high performance liquid
chromatography (HPLC). By optimizing separation and detection conditions,
we decreased the retention time of serotonin to 2.5 min and the detection
threshold to 0.8 fmol. Sampling times were consequently reduced from
20 to 3 min per sample for online detection of serotonin (and dopamine)
in brain dialysates using a commercial HPLC system. We developed a
strategy to collect and to analyze dialysate samples continuously
from two animals in tandem using the same instrument. Improvements
in temporal resolution enabled elucidation of rapid changes in extracellular
serotonin levels associated with mild stress and circadian rhythms.
These dynamics would be difficult or impossible to differentiate using
conventional microdialysis sampling rates
Three-Dimensional Conductive Gel Network as an Effective Binder for High-Performance Si Electrodes in Lithium-Ion Batteries
Silicon
(Si) has been widely investigated as a candidate for lithium-ion
batteries (LIBs) due to its extremely high specific capacity. The
binders play a key role in fabricating high-performance Si electrodes
which usually suffer from the huge volume expansion associated with
the alloying and dealloying processes. Here we develop a facile route
to prepare a three-dimensional (3D) conductive interpenetrated gel
network as a novel binder for high-performance Si anodes through chemically
cross-linking of acrylic acid monomer followed by the in situ polymerization
of aniline. The excellent electrical conductivity, strong mechanical
adhesion and high electrolyte uptake render the conductive gel network
a potential binder for high-performance Si anodes. The resultant Si
anodes exhibit excellent cycling stability, high Coulombic efficiency
and superior rate capability, revealing better electrochemical properties
compared to the Si anodes with conventional binders. The 3D conductive
gel binder could not only accommodate the volume expansion and maintain
electric connectivity, but also assist in the formation of stable
solid electrolyte interphase (SEI) films. Such a strategy sheds light
on the design of polymer binders in LIBs, especially for high-capacity
electrode materials with huge volume changes during long-term cycling
Quasi-Layer-by-Layer Growth of Pentacene on HOPG and Au Surfaces
High-resolution scanning
tunneling microscopy (STM) is a promising
method for characterizing organic semiconductors to obtain a deep
understanding of organic semiconductor physics. However, organic films
on conductive single-crystal substrates, which are required for STM,
usually present different growth behaviors than the films on inert
substrates such as SiO<sub>2</sub>. Here, we reported a simple modification
method for modulating the organic semiconductor film growth on the
highly oriented pyrolytic graphite (HOPG) and Au(111) substrates and
investigated the detailed morphology evolution. Self-assembled monolayers
(SAMs) fabricated from vacuum deposition and solution processing were
introduced on these conductive substrates. Pentacene, a prototypical
organic semiconductor, presented quasi-layer-by-layer growth on HOPG
or Au(111) sufaces modified with solution-processed alkane monolayer.
The pentacene film resembled the upright packing and terraced morphology
but with larger grain size than that of thin-film phase on SiO<sub>2</sub>. The introduced <i>n</i>-dotriacontane layer decreased
the interaction between pentacene adsorbates and the active substrate
and provided a lower surface energy which supported the upright orientation
of pentacene. Modification of the substrates with alkanes provides
a feasible approach to grow high-quality organic thin films that are
suitable for characterization down to the molecular level. Additionally,
this approach is effective for two-dimensional substrate materials
such as graphene and is not limited to single-crystal substrates
Small-Molecule Patterning via Prefunctionalized Alkanethiols
Interactions
between small molecules and biomolecules are important
physiologically and for biosensing, diagnostic, and therapeutic applications.
To investigate these interactions, small molecules can be tethered
to substrates through standard coupling chemistries. While convenient,
these approaches co-opt one or more of the few small-molecule functional
groups needed for biorecognition. Moreover, for multiplexing, individual
probes require different surface functionalization chemistries, conditions,
and/or protection/deprotection strategies. Thus, when placing multiple
small molecules on surfaces, orthogonal chemistries are needed that
preserve all functional groups and are sequentially compatible. Alternately,
we approach high-fidelity small-molecule patterning by coupling small-molecule
neurotransmitter precursors, as examples, to monodisperse asymmetric
oligo(ethylene glycol)alkanethiols during synthesis and prior to self-assembly
on Au substrates. We use chemical lift-off lithography to singly and
doubly pattern substrates. Selective antibody recognition of prefunctionalized
thiols was comparable to or better than recognition of small molecules
functionalized to alkanethiols after surface assembly. These findings
demonstrate that synthesis and patterning approaches that circumvent
sequential surface conjugation chemistries enable biomolecule recognition
and afford gateways to multiplexed small-molecule functionalized substrates
Controlled DNA Patterning by Chemical Lift-Off Lithography: Matrix Matters
Nucleotide arrays require controlled surface densities and minimal nucleotide–substrate interactions to enable highly specific and efficient recognition by corresponding targets. We investigated chemical lift-off lithography with hydroxyl- and oligo(ethylene glycol)-terminated alkanethiol self-assembled monolayers as a means to produce substrates optimized for tethered DNA insertion into post-lift-off regions. Residual alkanethiols in the patterned regions after lift-off lithography enabled the formation of patterned DNA monolayers that favored hybridization with target DNA. Nucleotide densities were tunable by altering surface chemistries and alkanethiol ratios prior to lift-off. Lithography-induced conformational changes in oligo(ethylene glycol)-terminated monolayers hindered nucleotide insertion but could be used to advantage <i>via</i> mixed monolayers or double-lift-off lithography. Compared to thiolated DNA self-assembly alone or with alkanethiol backfilling, preparation of functional nucleotide arrays by chemical lift-off lithography enables superior hybridization efficiency and tunability
Advancing Biocapture Substrates via Chemical Lift-Off Lithography
Creating
small-molecule-functionalized platforms for high-throughput
screening or biosensing applications requires precise placement of
probes on solid substrates and the ability to capture and to sort
targets from multicomponent samples. Here, chemical lift-off lithography
was used to fabricate large-area, high-fidelity patterns of small-molecule
probes. Lift-off lithography enables biotin–streptavidin patterned
recognition with feature sizes ranging from micrometers to below 30
nm. Subtractive patterning via lift-off facilitated insertion of a
different type of molecule and, thus, multiplexed side-by-side placement
of small-molecule probes such that binding partners were directed
to cognate probes from solution. Small molecules mimicking endogenous
neurotransmitters were patterned using lift-off lithography to capture
native membrane-associated receptors. We characterized patterning
of alkanethiols that self-assemble on Au having different terminal
functional groups to expand the library of molecules amenable to lift-off
lithography enabling a wide range of functionalization chemistries
for use with this simple and versatile patterning method
A Chinese version of the Language Screening Test (CLAST) for early-stage stroke patients
<div><p>There is a severe lack of aphasia screening tools for bedside use in Chinese. A number of aphasia assessment tools have recently been developed abroad, but some of these scales were not suitable for patients with acute stroke. The Language Screening Test (which includes two parallel versions [a/b]) in French has been proven to be an effective and time-saving aphasia screening scale for early-stage stroke patients. Therefore, we worked out a Chinese version of the LAST taking into consideration Chinese language and culture. Two preliminary parallel versions (a/b) were tested on 154 patients with stroke at acute phase and 107 patients with stroke at non-acute phase, with the Western Aphasia Battery serving as a gold standard. The equivalence between the two parallel versions and the reliability/validity of each version were assessed. The median time to complete one preliminary Chinese version (each had some item redundancy) was 98 seconds. Two final parallel versions were established after adjustment/elimination of the redundant items and were found to be equivalent (intra-class correlation coefficient: 0.991). Internal consistency is(Cronbach α for each version [a/b] was 0.956 and 0.965, respectively) good. Internal validity was fine: (a) no floor or ceiling effect/item redundancy; (b) construct validity revealed a 1-dimension structure, just like the French version. The higher educated subjects scored higher than their lower educated counterparts (<i>p<0</i>.<i>01</i>). The external validity: at the optimum cut-off point where the score of version a/b <14 in higher educated group(<13 in lower): the specificity of each version was 0.878/0.902(1/1 in lower) and sensitivity was 0.972/0.944(0.944/0.944 in lower). Inter-rater equivalence (intra-class correlation coefficient) was 1. The Chinese version of the Language Screening Test was proved to be an efficient and time-saving bedside aphasia screening tool for stroke patients at acute phase and can be used by an average medical physician.</p></div
Baseline data of all patients, including the educational level of all patients(n = 261) and lesion sites of the non-acute patients(n = 107).
<p>Baseline data of all patients, including the educational level of all patients(n = 261) and lesion sites of the non-acute patients(n = 107).</p