High-entropy alloys (HEAs) with unique physicochemical properties have attracted tremendous attention in many fields, yet the precise control on dimension and morphology at atomic level remains ...formidable challenges. Herein, we synthesize unique PtRuNiCoFeMo HEA subnanometer nanowires (SNWs) for alkaline hydrogen oxidation reaction (HOR). The mass and specific activities of HEA SNWs/C reach 6.75 A mg
and 8.96 mA cm
, respectively, which are 2.8/2.6, 4.1/2.4, and 19.8/18.7 times higher than those of HEA NPs/C, commercial PtRu/C and Pt/C, respectively. It can even display enhanced resistance to CO poisoning during HOR in the presence of 1000 ppm CO. Density functional theory calculations reveal that the strong interactions between different metal sites in HEA SNWs can greatly regulate the binding strength of proton and hydroxyl, and therefore enhances the HOR activity. This work not only provides a viable synthetic route for the fabrication of Pt-based HEA subnano/nano materials, but also promotes the fundamental researches on catalysis and beyond.
Described herein is an organocatalytic enantioselective desymmetrizing cycloisomerization of arylsulfonyl‐protected ynamide cyclohexanones, representing the first metal‐free asymmetric Conia‐ene‐type ...carbocyclization. This method allows the highly efficient and atom‐economical construction of a range of valuable morphans with wide substrate scope and excellent enantioselectivity (up to 97 % ee). In addition, such a cycloisomerization of alkylsulfonyl‐protected ynamide cyclohexanones can lead to the divergent synthesis of normorphans as the main products with high enantioselectivity (up to 90 % ee). Moreover, theoretical calculations are employed to elucidate the origins of regioselectivity and enantioselectivity.
An organocatalytic enantioselective desymmetrizing cycloisomerization of arylsulfonyl‐protected ynamide cyclohexanones is disclosed for practical and atom‐economical assembly of morphans with excellent enantioselectivities. It represents the first metal‐free asymmetric Conia‐ene‐type carbocyclization. In addition, cycloisomerization of the alkylsulfonyl‐protected ynamide cyclohexanones leads to normorphans with high enantioselectivities.
Exploring new materials is essential in the field of material science. Especially, searching for optimal materials with utmost atomic utilization, ideal activities and desirable stability for ...catalytic applications requires smart design of materials' structures. Herein, we report iridium metallene oxide: 1 T phase-iridium dioxide (IrO
) by a synthetic strategy combining mechanochemistry and thermal treatment in a strong alkaline medium. This material demonstrates high activity for oxygen evolution reaction with a low overpotential of 197 millivolt in acidic electrolyte at 10 milliamperes per geometric square centimeter (mA cm
). Together, it achieves high turnover frequencies of 4.2 s
(3.0 s
) at 1.50 V vs. reversible hydrogen electrode. Furthermore, 1T-IrO
also shows little degradation after 126 hours chronopotentiometry measurement under the high current density of 250 mA cm
in proton exchange membrane device. Theoretical calculations reveal that the active site of Ir in 1T-IrO
provides an optimal free energy uphill in *OH formation, leading to the enhanced performance. The discovery of this 1T-metallene oxide material will provide new opportunities for catalysis and other applications.
Chiral Brønsted acid-catalysed asymmetric synthesis has received tremendous interest over the past decades, and numerous efficient synthetic methods have been developed based on this approach. ...However, the use of chiral Brønsted acids in these reactions is mostly limited to the activation of imine and carbonyl moieties, and the direct activation of carbon–carbon triple bonds has so far not been invoked. Here we show that chiral Brønsted acids enable the catalytic asymmetric dearomatization reactions of naphthol-, phenol- and pyrrole-ynamides by the direct activation of alkynes. This method leads to the practical and atom-economic construction of various valuable spirocyclic enones and 2H-pyrroles that bear a chiral quaternary carbon stereocentre in generally good-to-excellent yields with excellent chemo-, regio- and enantioselectivities. The activation mode of chiral Brønsted acid catalysis revealed in this study is expected to be of broad utility in catalytic asymmetric reactions that involve ynamides and the related heteroatom-substituted alkynes.Chiral Brønsted acid catalysis is mostly limited to the activation of imine and carbonyl moieties. Now, by direct activation of alkynes, chiral Brønsted acids have been used to enable the catalytic asymmetric dearomatization of naphthol-, phenol- and pyrrole-ynamides for the construction of various spirocyclic enones and 2H-pyrroles bearing a chiral quaternary carbon stereocentre.
•The economic and environmental impacts of the Hubei Pilot ETS are assessed by applying TermCO2 model.•The carbon emission of Hubei is reduced by 1.00% and the provincial GDP declines by 0.06% in ...2014.•Elasticity of GDP to carbon reduction is 0.06, and the average GDP loss is 212.09 Yuan per ton in Hubei.•The provincial employment and investment rate decreases by 0.09% and 0.33% respectively.
Among the seven Pilot Emission Trading Schemes (ETS) in China, the ETS in Hubei province exerts significant influences. And Hubei’s economic and social contexts are very similar to China as a whole. By applying a Chinese multi-regional general equilibrium model (TermCO2), this paper simulates the economic and environmental impacts of the Hubei Pilot ETS, under a scenario based on the institutional factors of this Pilot ETS and careful consideration is given to ETS coverage. The results show that the Hubei Pilot ETS has significantly reduced carbon emission while its adverse impact on economy is relatively negligible. The carbon emission of Hubei in 2014 is reduced by 1.00% (6.98 million tons) at an average carbon price of 34.31 Yuan per ton. However, the provincial GDP only declines slightly by 0.06% (1.48 billion Yuan) and the average GDP loss is 212.09 Yuan per ton. Meanwhile, Hubei’s economic structure has been adjusted, and the provincial employment and investment rate decreases by 0.09% and 0.33% respectively. However, due to income distribution effect caused by free allowances, the provincial household consumption increases by 0.35% and the consumer price index (CPI) increases slightly by about 0.02%.
A new TiIII‐mediated reductive epoxide‐opening/ Beckwith–Dowd rearrangement process efficiently assembles the bicyclo3.2.1octane framework of highly oxidized grayanane diterpenoids. By incorporation ...of a Cu(tbs)2‐catalyzed (tbs=N‐tert‐butylsalicylaldiminato) intramolecular cyclopropanation, a diastereoselective oxidative dearomatization‐induced Diels–Alder cycloaddition and a MeReO3‐catalyzed Rubottom oxidation, this approach has enabled the first total syntheses of rhodomolleins XX and XXII in 23 and 22 steps, respectively.
Fusing cycles: A new TiIII‐mediated reductive epoxide‐opening/Beckwith–Dowd rearrangement efficiently assembles the bicyclo3.2.1octane framework of highly oxidized grayanane diterpenoids. This reaction, along with a CuII‐catalyzed intramolecular cyclopropanation, a diastereoselective oxidative dearomatization‐induced (ODI) Diels–Alder cycloaddition, and a MeReO3‐catalyzed Rubottom oxidation, were key steps in the first total syntheses of rhodomolleins XX and XXII.
The overall response of cisplatin-based chemotherapy in bladder urothelial carcinoma (BUC) remains unsatisfactory due to the complex pathological subtypes, genomic difference, and drug resistance. ...The genes that associated with cisplatin resistance remain unclear. Herein, we aimed to identify the cisplatin resistance associated genes in BUC. EXPERIMENTAL DESIGN: The cytotoxicity of cisplatin was evaluated in six bladder cancer cell lines to compare their responses to cisplatin. The T24 cancer cells exhibited the lowest sensitivity to cisplatin and was therefore selected to explore the mechanisms of drug resistance. We performed genome-wide CRISPR screening in T24 cancer cells in vitro, and identified that the gene heterogeneous nuclear ribonucleoprotein U (HNRNPU) was the top candidate gene related to cisplatin resistance. Epigenetic and transcriptional profiles of HNRNPU-depleted cells after cisplatin treatment were analyzed to investigate the relationship between HNRNPU and cisplatin resistance. In vivo experiments were also performed to demonstrate the function of HNRNPU depletion in cisplatin sensitivity.
Significant correlation was found between HNRNPU expression level and sensitivity to cisplatin in bladder cancer cell lines. In the high HNRNPU expressing T24 cancer cells, knockout of HNRNPU inhibited cell proliferation, invasion, and migration. In addition, loss of HNRNPU promoted apoptosis and S-phase arrest in the T24 cells treated with cisplatin. Data from The Cancer Genome Atlas (TCGA) demonstrated that HNRNPU expression was significantly higher in tumor tissues than in normal tissues. High HNRNPU level was negatively correlated with patient survival. Transcriptomic profiling analysis showed that knockout of HNRNPU enhanced cisplatin sensitivity by regulating DNA damage repair genes. Furthermore, it was found that HNRNPU regulates chemosensitivity by affecting the expression of neurofibromin 1 (NF1).
Our study demonstrated that HNRNPU expression is associated with cisplatin sensitivity in bladder urothelial carcinoma cells. Inhibition of HNRNPU could be a potential therapy for cisplatin-resistant bladder cancer.
Abstract
The oxygen evolution reactions in acid play an important role in multiple energy storage devices. The practical promising Ru-Ir based catalysts need both the stable high oxidation state of ...the Ru centers and the high stability of these Ru species. Here, we report stable and oxidative charged Ru in two-dimensional ruthenium-iridium oxide enhances the activity. The Ru
0.5
Ir
0.5
O
2
catalyst shows high activity in acid with a low overpotential of 151 mV at 10 mA cm
−2
, a high turnover frequency of 6.84 s
−1
at 1.44 V versus reversible hydrogen electrode and good stability (618.3 h operation). Ru
0.5
Ir
0.5
O
2
catalysts can form more Ru active sites with high oxidation states at lower applied voltages after Ir incorporation, which is confirmed by the pulse voltage induced current method. Also, The X-ray absorption spectroscopy data shows that the Ru-O-Ir local structure in two-dimensional Ru
0.5
Ir
0.5
O
2
solid solution improved the stability of these Ru centers.
While overall water splitting is considered as one of the most efficient approaches for sustainable oxygen and hydrogen generations, the design of robust electrocatalysts that are active and stable ...for overall water splitting in pH‐universal conditions is still a significant challenge. Herein, a universal strategy for a class of metal wavy nanowires (NWs) for the enhanced electrocatalysis is reported. Benefiting from the structural features of ultrathin nature and numbers of defects, the obtained NWs generally exhibit attractive performances in oxygen evolution reaction (OER) and hydrogen evolution reaction at pH‐universal conditions. More significantly, the optimized Ru O2 NWs‐Ir NWs electrolyzer shows superior performance for overall water splitting with only cell voltages of 1.50 and 1.47 V in 0.05 and 0.5 m H2SO4 and 1.56 and 1.49 V in 0.1and 1 m KOH at 10 mA cm−2, much lower than those of the Ir/C‐Pt/C electrolyzer. First‐principles calculations reveals that the appearance of Ru‐atom point defects on RuO2(200) surface will lower the OER overpotential during which the adsorption free energies of OER intermediates are weakened due to the right‐shift of d‐band center. The RuO2 NWs‐Ir NWs electrolyzer also exhibits excellent durability in long‐term electrolysis, showing exciting prospect for water splitting in different pH electrolytes.
A new class of M (Ru, Rh, Ir, and Pt) wavy nanowires (NWs) is described. Benefiting from ultrathin features and plenty of defects, those wavy NWs are highly active and stable towards the hydrogen evolution reaction, the oxygen evolution reaction as well as overall water splitting at pH‐universal conditions.
Staphylococcus aureus
is a bacterial pathogen that causes food poisoning, various infections, and sepsis. Effective strategies and new drugs are needed to control
S. aureus
associated infections due ...to the emergence and rapid dissemination of antibiotic resistance. In the present study, the antibacterial activity, potential mode of action, and applications of flavonoids from licorice were investigated. Here, we showed that glabrol, licochalcone A, licochalcone C, and licochalcone E displayed high efficiency against methicillin-resistant
Staphylococcus aureus
(MRSA). Glabrol, licochalcone A, licochalcone C, and licochalcone E exhibited low cytotoxicity without hemolytic activity based on safety evaluation. Glabrol displayed rapid bactericidal activity with low levels of resistance development
in vitro
. Meanwhile, glabrol rapidly increased bacterial membrane permeability and dissipated the proton move force. Furthermore, we found that peptidoglycan, phosphatidylglycerol, and cardiolipin inhibited the antibacterial activity of glabrol. Molecular docking showed that glabrol binds to phosphatidylglycerol and cardiolipin through the formation of hydrogen bonds. Lastly, glabrol showed antibacterial activity against MRSA in both
in vivo
and
in vitro
models. Altogether, these results suggest that glabrol is a promising lead compound for the design of membrane-active antibacterial agents against MRSA and can be used as a disinfectant candidate as well.
Glabrol isolated from licorice rapidly kill MRSA
via
the disruption of the membrane permeability and the proton motive force.
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