In this work, a record high thermoelectric figure‐of‐merit ZT of 1.6 ± 0.2 at 873 K in p‐type polycrystalline Bi0.94Pb0.06CuSe1.01O0.99 by a synergy of rational band manipulation and novel ...nanostructural design is reported. First‐principles density functional theory calculation results indicate that the density of state at the Fermi level that crosses the valence band can be significantly reduced and the measured optical bandgap can be enlarged from 0.70 to 0.74 eV by simply replacing 1% O with 1% Se, both indicating a potentially reduced carrier concentration and in turn, an improved carrier mobility and a boosted power factor up to 9.0 µW cm−1 K−2. Meanwhile, comprehensive characterizations reveal that under Se‐rich condition, Cu2Se secondary microphases and significant lattice distortions triggered by Pb‐doping and Se‐substitution can be simultaneously achieved, contributing to a reduced lattice thermal conductivity of 0.4 W m−1 K−1. Furthermore, a unique shear exfoliation technique enables an effective grain refinement with higher anisotropy of the polycrystalline pellet, leading to a further improved power factor up to 10.9 µW cm−1 K−2 and a further reduced lattice thermal conductivity of 0.30 W m−1 K−1, which gives rise to record high ZT.
A record high thermoelectric figure‐of‐merit ZT of 1.6 ± 0.2 at 873 K in p‐type polycrystalline Bi0.94Pb0.06CuSe1.01O0.99 by a synergy of rational band manipulation and novel nanostructural design is reported.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Mortality from hepatitis B virus (HBV)–related acute‐on‐chronic liver failure (ACLF) is high due to limited treatment options. Preclinical and clinical investigations have proved that treatment with ...mesenchymal stromal cells (MSCs) is beneficial for recovery from liver injury. We hypothesized that the outcome of HBV‐related ACLF would be improved by MSC treatment. From 2010 to 2013, 110 patients with HBV‐related ACLF were enrolled in this open‐label, nonblinded randomized controlled study. The control group (n = 54) was treated with standard medical therapy (SMT) only. The experimental group (n = 56) was infused weekly for 4 weeks with 1.0 to 10 × 105 cells/kg allogeneic bone marrow–derived MSCs and then followed for 24 weeks. The cumulated survival rate of the MSC group was 73.2% (95% confidence interval 61.6%‐84.8%) versus 55.6% (95% confidence interval 42.3%‐68.9%) for the SMT group (P = 0.03). There were no infusion‐related side effects, but fever was more frequent in MSC compared to SMT patients during weeks 5‐24 of follow‐up. No carcinoma occurred in any trial patient in either group. Compared with the control group, allogeneic bone marrow–derived MSC treatment markedly improved clinical laboratory measurements, including serum total bilirubin and Model for End‐Stage Liver Disease scores. The incidence of severe infection in the MSC group was much lower than that in the SMT group (16.1% versus 33.3%, P = 0.04). Mortality from multiple organ failure and severe infection was higher in the SMT group than in the MSC group (37.0% versus 17.9%, P = 0.02). Conclusion: Peripheral infusion of allogeneic bone marrow–derived MSCs is safe and convenient for patients with HBV‐related ACLF and significantly increases the 24‐week survival rate by improving liver function and decreasing the incidence of severe infections. (Hepatology 2017;66:209–219).
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Cancer metastasis, a leading cause of death in patients, is associated with aberrant expression of epigenetic modifiers, yet it remains poorly defined how epigenetic readers drive metastatic growth ...and whether epigenetic readers are targetable to control metastasis. Here, we report that bromodomain-containing protein 4 (BRD4), a histone acetylation reader and emerging anticancer therapeutic target, promotes progression and metastasis of gastric cancer. The abundance of BRD4 in human gastric cancer tissues correlated with shortened metastasis-free gastric cancer patient survival. Consistently, BRD4 maintained invasiveness of cancer cells
and their dissemination at distal organs
. Surprisingly, BRD4 function in this context was independent of its putative transcriptional targets such as MYC or BCL2, but rather through stabilization of Snail at posttranslational levels. In an acetylation-dependent manner, BRD4 recognized acetylated lysine 146 (K146) and K187 on Snail to prevent Snail recognition by its E3 ubiquitin ligases FBXL14 and β-Trcp1, thereby inhibiting Snail polyubiquitination and proteasomal degradation. Accordingly, genome-wide transcriptome analyses identified that BRD4 and Snail regulate a partially shared metastatic gene signature in gastric cancer cells. These findings reveal a noncanonical posttranscriptional regulatory function of BRD4 in maintaining cancer growth and dissemination, with immediate translational implications for treating gastric metastatic malignancies with clinically available bromodomain inhibitors. SIGNIFICANCE: These findings reveal a novel posttranscriptional regulatory function of the epigenetic reader BRD4 in cancer metastasis via stabilizing Snail, with immediate translational implication for treating metastatic malignancies with clinically available bromodomain inhibitors. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/79/19/4869/F1.large.jpg.
Nano‐/micro‐reactors have emerged as a powerful platform for chemical synthesis. Here, we develop fiber‐spinning chemistry (FSC) based on a microfluidic blow spinning (MBS) technique, allowing the ...availability of nanoreactors for chemical synthesis with scale‐up capacities. Proof‐of‐concept experiments focus on the utilization of MBS‐derived fibrous nanoreactors for large‐scale production of ligand‐free perovskite quantum dots (PQDs) in one step. Typically, methylammonium lead halide (MAPbX3, X=Cl, Br, and I) PQDs in situ synthesized at large scale inside polyacrylonitrile (PAN) nanofiber films (size 120 cm ×30 cm per hour), exhibit high photoluminescence (PL) quantum yield (QY) of 71 %, tunable emissive peaks (448–600 nm), and superb PL stability. The PQDs/polymer nanofiber films are potentially useful for CO2 conversion, wide‐color‐gamut displays and light‐emitting diode (LED) devices. These findings may guide the development of nano‐/micro‐reactor technology for scale‐up production of nanomaterials with various potential applications.
Fiber‐spinning chemistry based on a microfluidic blow spinning (MBS) technique is developed to construct fibrous nanoreactors allowing mass production of ligand‐free perovskite quantum dots (PQDs). The resultant PQDs/polymer nanofiber films possess high fluorescence stability under extreme conditions like light irradiation, heating and water dipping, which show potential applications in photocatalytic CO2 reduction and optoelectronic devices.
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Improving the separation of photogenerated carriers and suppressing the rapid complication of electron–hole pairs are essential ways to improve photocatalytic hydrogen production activity. The high ...recombination rate of the photogenerated carriers is an issue encountered when developing CdS as a promising photocatalytic material. This work allowed to accelerate the separation of photogenerated electrons and holes by loading monoclinic β-AgVO
3
on hexagonal CdS nanorods to construct a one-dimensional (1D)/1D p-n heterojunction. The introduction of monoclinic β-AgVO
3
with a narrow band gap effectively improves the light absorption of CdS, which is conducive to improving the use of visible light. The integrated electric field of the p–n heterojunction can effectively transfer electrons and holes in the direction suitable to hydrogen evolution. The photoluminescence and electrochemical characterization of the catalysts showed that the p–n heterojunction formed after loading β-AgVO
3
greatly improved the separation efficiency of photocarriers. The hydrogen evolution experiments show that the composite catalyst has good photocatalytic hydrogen evolution capability and stability. The composite catalyst with the best photocatalytic performance was obtained by studying β-AgVO
3
with different loadings. The composite catalyst reached 581.5 μmol of hydrogen amount within 5 h, which is 3.8 times higher than that of CdS alone and its apparent quantum efficiency reaches 8.02%. The present work provides a possible solution for the development of perovskite and the extensiveness of CdS in photocatalytic hydrogen evolution.
Graphical abstract
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Graphdiyne (g−CnH2n‐2), a novel two‐dimension carbon allotrope material composed of a sp‐ and sp2‐hybrid carbon network, has been widely explored since it was synthesized for the first time by Li's ...group in 2010. A series distinct and excellent properties bestow graphdiyne excellent performance in many fields. Here, an innovative progress for preparing graphdiyne by using Cu+ contained material as catalyst is reported and the composite CuI‐GD is coupled with flower‐like NiAl‐LDH to produce H2 from photocatalytic water splitting. The results of FTIR and Raman spectroscopy together reveal that graphdiyne nanosheets are synthesized successfully by employing a cross‐coupling method. Photocatalytic hydrogen evolution performance shows that the hydrogen production activity of CuI‐GD/NiAl‐LDH has a 15‐ and 216‐fold enhancement compared with CuI‐GD and NiAl‐LDH, respectively. A series of characterizations are carried out to expound the underlying reasons in the enhancement of the photocatalytic hydrogen production performance of CuI‐GD/NiAl‐LDH. Meanwhile, a possible mechanism for the photocatalytic hydrogen evolution process was proposed to understand the interaction among these materials.
Graphdyine nanosheets were synthesized successfully by employing cross‐coupling method with CuI as the catalyst and the composite copper iodide‐graphdyine (CuI‐GD) composite was coupled with the flower‐like layered double hydroxide (NiAl‐LDH) to construct an S‐scheme for producing H2 from photocatalytic water splitting. The spherical flower‐like NiAl‐LDH can support CuI‐GD to prevent it from aggregation. A greatly improved photocatalytic hydrogen evolution performance was obtained in the sensitized system.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Engineering single-atom electrocatalysts with high-loading amount holds great promise in energy conversion and storage application. Herein, we report a facile and economical approach to achieve an ...unprecedented high loading of single Ir atoms, up to ∼18wt%, on the nickel oxide (NiO) matrix as the electrocatalyst for oxygen evolution reaction (OER). It exhibits an overpotential of 215 mV at 10 mA cm–2 and a remarkable OER current density in alkaline electrolyte, surpassing NiO and IrO2 by 57 times and 46 times at 1.49 V vs RHE, respectively. Systematic characterizations, including X-ray absorption spectroscopy and aberration-corrected Z-contrast imaging, demonstrate that the Ir atoms are atomically dispersed at the outermost surface of NiO and are stabilized by covalent Ir–O bonding, which induces the isolated Ir atoms to form a favorable ∼4+ oxidation state. Density functional theory calculations reveal that the substituted single Ir atom not only serves as the active site for OER but also activates the surface reactivity of NiO, which thus leads to the dramatically improved OER performance. This synthesis method of developing high-loading single-atom catalysts can be extended to other single-atom catalysts and paves the way for industrial applications of single-atom catalysts.
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IJS, KILJ, NUK, PNG, UL, UM
Organometallic reagents prepared from main group metals have played a central role in the advancement of synthetic organic chemistry. However, the sensitivity of these reactive organometallic species ...to moisture and air rendered the preparation and handling of these reagents difficult. As a result, organoindium reagent, backed by several decades of development, has emerged as an attractive alternative to the aforementioned reactive organometallic species.
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Developing low cost and highly active catalysts for the oxygen evolution reaction (OER) in an acidic medium is urgently indispensable for proton exchange membrane water electrolyzers (PEMWEs). ...Herein, we have prepared ultra-thin RuO
2
nanosheets (RuO
2
NSs) using a simple molten salt method. The as-prepared RuO
2
NSs with a thickness of 1-2 nm possess abundant defects. Toward the OER, the RuO
2
NSs achieve an extremely low overpotential of 199 mV at a current density of 10 mA cm
geo
−2
with a loading of 125 μg cm
geo
−2
. Furthermore, the RuO
2
NSs exhibit specific and mass activities of up to 0.89 mA cm
oxide
−2
and 0.52 A mg
Ru
−1
at 1.46 V
vs.
RHE, which are 14.9 and 80.6 times enhanced in specific and mass activity as compared to the commercial RuO
2
nanoparticles, respectively. In a homemade PEMWE, with RuO
2
NSs as the OER catalyst, the electrolyzer achieves a current density of 0.93 A cm
−2
at a cell voltage of 1.65 V without
iR
drop correction, which is 3 times larger than that of the commercial RuO
2
catalyst (0.31 A cm
−2
). Density functional theory calculations indicate that the Ru vacancy on the RuO
2
NS surfaces significantly weakens the binding energy of O* with respect to that of OOH*, which decreases the energy cost in the transformation from O* to OOH*, and thus dramatically enhances the OER performance. The unique defect-rich structure and outstanding performance demonstrate that the RuO
2
NSs possess great potential for developing high-performance PEMWEs.
A Ru vacancy decreases the energy barrier from O* to OOH*, thus dramatically enhancing the OER performance of defect-rich RuO
2
nanosheets.
Abstract
Copper-based materials are promising electrocatalysts for CO
2
reduction. Prior studies show that the mixture of copper (I) and copper (0) at the catalyst surface enhances multi-carbon ...products from CO
2
reduction; however, the stable presence of copper (I) remains the subject of debate. Here we report a copper on copper (I) composite that stabilizes copper (I) during CO
2
reduction through the use of copper nitride as an underlying copper (I) species. We synthesize a copper-on-nitride catalyst that exhibits a Faradaic efficiency of 64 ± 2% for C
2+
products. We achieve a 40-fold enhancement in the ratio of C
2+
to the competing CH
4
compared to the case of pure copper. We further show that the copper-on-nitride catalyst performs stable CO
2
reduction over 30 h. Mechanistic studies suggest that the use of copper nitride contributes to reducing the CO dimerization energy barrier—a rate-limiting step in CO
2
reduction to multi-carbon products.
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