77 research outputs found
EDTA-Induced Self-Assembly of 3D Graphene and Its Superior Adsorption Ability for Paraquat Using a Teabag
In the past two years, three-dimensional
graphene (3DG) was introduced to the environmental treatment area
as a promising new material. Despite much progress in its synthesis
and applications, 3DG is still limited in terms of green large-scale
synthesis and practical environmental applications. In this work,
a 3DG synthetic method was developed at 95 °C in an EDTA-induced
self-assembly process. Because little EDTA was found to be consumed
during synthesis, which might be due to its great stability and poor
reducibility, 3DG with complete structure can be successively obtained
by reusing the EDTA solution more than 10 times. Furthermore, 3DG
was found to possess a superior adsorption capacity of 119 mg g<sup>–1</sup> (pH 6.0) for paraquat, a highly toxic herbicide with
positive charges and a conjugated system of π bonds in its molecular
structure. The adsorption capacity was much higher than those in classic
paraquat adsorbents, such as clay and activated carbon. To address
the problem of 3DG damage by stirring, a pyramid-shaped nylon teabag
was adopted to protect the soft hydrogel during the repeated adsorption–desorption
processes. After five cycles, the 3DG teabag still maintained 88%
of the initial adsorption capacity. This facile method may be easily
applied in other environmental treatment conditions
Additional file 2: of Laboratory tests as short-term correlates of stroke
The Relative Risk (with confidence intervals), the correlations computed between different tests, the description and range of observed values for each test. (XLSX 48 kb
Intrinsic Point Defects in Inorganic Cesium Lead Iodide Perovskite CsPbI<sub>3</sub>
Cesium lead iodide
(CsPbI<sub>3</sub>) has recently emerged as
a promising solar photovoltaic absorber. However, the cubic perovskite
(α-phase) remains stable only at high temperature and reverts
to a photoinactive nonperovskite (δ-phase) CsPbI<sub>3</sub> at room temperature. In this work, the formation energies and transition
energy levels of intrinsic point defects in γ- (more stable
than α-phase) and δ-phases have been studied systematically
by first-principles calculations. It is found that CsPbI<sub>3</sub> exhibits a unipolar self-doping behavior (p-type conductivity),
which is in contrast to CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub>. Most of the intrinsic defects induce deeper transition energy levels
in δ-phase than in γ-phase. This is due to the small Pb–I–Pb
bond angles in δ-phase that results in the weak antibonding
character of valence band maximum (VBM). However, the strong antibonding
character of VBM plays a critical role in keeping defect tolerance
in semiconductors. Therefore, these results indicate the importance
of the large metal–halide–metal bond angle for the performance
of perovskite solar cells
Additional file 1: Table S1. of Laboratory tests as short-term correlates of stroke
Racial/ethnic distribution of patients in the dataset. Table S2. Correlations between different laboratory tests. (PDF 277 kb
Proton-Insertion-Enhanced Pseudocapacitance Based on the Assembly Structure of Tungsten Oxide
The
capacitances of supercapacitors with carbon and metal oxides as electrodes
are usually associated with the available surface areas of the electrode
materials. However, in this paper, we report that proton insertion,
an unusual capacitive mechanism, may effectively enhance the capacitance
of metal oxides with low surface area but specific structures. Tungsten
trioxide (WO<sub>3</sub>) as the electrode material for supercapacitors
has always suffered from low capacitance. Nevertheless, enhanced by
the proton insertion mechanism, we demonstrate that electrodes fabricated
by an assembly structure of hexagonal-phase WO<sub>3</sub> (<i>h</i>-WO<sub>3</sub>) nanopillars achieve a high capacitance
of up to 421.8 F g<sup>–1</sup> under the current density of
0.5 A g<sup>–1</sup>, which is the highest capacitance achieved
with pure WO<sub>3</sub> as the electrodes so far, to the best of
our knowledge. Detailed analyses indicate that proton insertion dominates
the electrochemical behavior of <i>h</i>-WO<sub>3</sub> and
plays the key role in reaching high capacitance by excluding other
mechanisms. In addition, a thorough investigation on the temperature-dependent
electrochemical performance reveals excellent performance stability
at different temperatures. This study provides a new approach to achieving
high capacitance by effective proton insertion into ordered tunnels
in crystallized metal oxides, which is primarily important for the
fabrication of compact high-performance energy storage devices
Highly Isoselective and Active Zinc Catalysts for <i>rac</i>-Lactide Polymerization: Effect of Pendant Groups of Aminophenolate Ligands
Highly isoselective and active ring-opening
polymerization of <i>rac</i>-lactide to obtain stereocomplexed
polylactide is a long-standing
challenge. In this contribution, zinc catalysts with good isoselectivities
and high activities (<i>P</i><sub>m</sub> = 0.87, TOF =
3312 h<sup>–1</sup> at 25 °C; <i>P</i><sub>m</sub> = 0.92, TOF = 117 h<sup>–1</sup> at −20 °C, toluene)
for <i>rac</i>-lactide polymerization are reported. These
catalysts are coordinated by a well-designed chiral oxazolinyl or
achiral benzoxazolyl aminophenolate ligand. Both types of zinc complexes
afforded multiblock isotactic PLAs, proving to be formed via a chain-end
control mechanism regardless of the existence of a chiral group or
not. Preliminary studies suggested that the dihedral angle between
the phenoxy and oxazolinyl/benzoxazolyl planes in these complexes
reflects the steric bulkiness of the ligand and has a close relation
with the isoselectivity of the complex, which might serve as a guide
in obtaining new isoselective catalysts of similar types. Furthermore,
unprecedented combination of excellent activity (TOF up to 44 000
h<sup>–1</sup>) and sufficient isoselectivity (<i>P</i><sub>m</sub> = 0.80) could be achieved under solvent-free immortal
conditions with catalyst loadings as low as 0.005 mol % (vs monomer),
which shows the potential of industrial application
Mixed Starter Culture Regulates Biogenic Amines Formation via Decarboxylation and Transamination during Chinese Rice Wine Fermentation
The
utilization of amine-negative starter based on an understanding
of nitrogen metabolism is a useful method for controlling biogenic
amine (BA) in Chinese rice wine (CRW) fermentation. The contribution
of brewing materials to protein degradation was analyzed; wheat Qu
protein had no effect, and yeast autolysis generated 10% amino nitrogen.
Milling degree of rice was strongly correlated with BAs formation
(<i>R</i><sup>2</sup> = 0.99). Subsequently, Lactobacillus plantarum and Staphylococcus
xylosus were coinoculated as amine-negative starter
at an optimized ratio of 1:2. Coinoculation induced a significant
reduction in total BAs (43.7%, 44.5 mg L<sup>–1</sup>), putrescine
(43.0%, 20.4 mg L<sup>–1</sup>), tyramine (42.8%, 14.3 mg L<sup>–1</sup>), and histamine (42.6%, 3.5 mg L<sup>–1</sup>) content. Notably, BAs degradation ability of Staphylococcus
xylosus was stronger than the suppression effect of Lactobacillus plantarum, and higher lactic acid bacteria
(LAB) amount has a positive correlation with lower BAs content. Overall,
mixed strains exerted a synergistic effect in lowering BAs accumulation
via decarboxylation and transamination
The three bio-markers expression in well, moderate and pooly differentiated tumor tissues.
<p>(G) COX-2 expression in well differentiated tumor tissues. (H) COX-2 expression in moderate differentiated tumor tissues. (I) COX-2 expression in poorly differentiated tumor tissues. (J) CD44v6 expression in well differentiated tumor tissues. (K) CD44v6 expression in moderate differentiated tumor tissues. (L) CD44v6 expression in poorly differentiated tumor tissues. (M) CD147 expression in well differentiated tumor tissues. (N) CD147 expression in moderate differentiated tumor tissues. (O) CD147 expression in poorly differentiated tumor tissues.</p
The three bio-markers expression by immunohistochemistry.
<p>(A) High levels of COX-2 expression in hypopharyngeal squamous cell carcinoma: diffuse cytoplasmic staining. (B) Low levels of COX-2 expression in epithelium adjacent to carcinoma. (C) High levels of CD44v6 expression in hypopharyngeal squamous cell carcinoma: cell membrane staining. (D) High levels of CD44v6 expression in epithelium adjacent to carcinoma as well as staining in carcinoma tissues. (E) High levels of CD147 expression in hypopharyngeal squamous cell carcinoma: diffuse cytoplasmic staining. (F) Low level of CD147 expression in epithelium adjacent to carcinoma.</p
Correlation of clinicopathologic characteristics of the patients with immunohistochemistry results.
*<p><i>P</i><0.001.</p
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