Single atom catalysts (SACs) have been widely studied in the field of CO2 electroreduction, but industrial‐level current density and near‐unity product selectivity are still difficult to achieve. ...Herein, a diatomic site catalysts (DASCs) consisting of Co‐Cu hetero‐diatomic pairs is synthesized. The CoCu DASC exhibits excellent selectivity with the maximum CO Faradaic efficiency of 99.1 %. The CO selectivity can maintain above 95 % over a wide current density range from 100 mA cm−2 to 500 mA cm−2. The maximum CO partial current density can reach to 483 mA cm−2 in flow cell, far exceed industrial‐level current density requirements (>200 mA cm−2). Theoretical calculation reveals that the synergistic catalysis of the Co‐Cu bimetallic sites reduce the activation energy and promote the formation of intermediate *COOH. This work shows that the introduction of another metal atom into SACs can significantly affect the electronic structure and then enhance the catalytic activity of SACs.
A diatomic site catalyst consisting of Co‐Cu hetero‐diatomic pairs is designed via a general and facile method. Industrial‐level current density can be easily achieved in a flow cell system with the maximum CO partial current density up to 483 mA cm−2. The CO selectivity can be maintained above 95 % over a wide current density range from 100 mA cm−2 to 500 mA cm−2.
It is still a great challenge to achieve high selectivity of CH4 in CO2 electroreduction reactions (CO2RR) because of the similar reduction potentials of possible products and the sluggish kinetics ...for CO2 activation. Stabilizing key reaction intermediates by single type of active sites supported on porous conductive material is crucial to achieve high selectivity for single product such as CH4. Here, Cu2O(111) quantum dots with an average size of 3.5 nm are in situ synthesized on a porous conductive copper‐based metal–organic framework (CuHHTP), exhibiting high selectivity of 73 % towards CH4 with partial current density of 10.8 mA cm−2 at −1.4 V vs. RHE (reversible hydrogen electrode) in CO2RR. Operando infrared spectroscopy and DFT calculations reveal that the key intermediates (such as *CH2O and *OCH3) involved in the pathway of CH4 formation are stabilized by the single active Cu2O(111) and hydrogen bonding, thus generating CH4 instead of CO.
Cu2O(111) single‐type sites on a conductive metal–organic framework are successfully prepared by an in situ electrochemical method. The cooperative effect between the single active Cu2O(111) and hydrogen bonding contributes to the high selectivity of 73 % towards CH4 with large current density in CO2 electroreduction reduction for the obtained Cu2O(111)@CuHHTP.
The electrocatalytic conversion of CO2 into value‐added chemicals is a promising approach to realize a carbon‐energy balance. However, low current density still limits the application of the CO2 ...electroreduction reaction (CO2RR). Metal–organic frameworks (MOFs) are one class of promising alternatives for the CO2RR due to their periodically arranged isolated metal active sites. However, the poor conductivity of traditional MOFs usually results in a low current density in CO2RR. We have prepared conductive two‐dimensional (2D) phthalocyanine‐based MOF (NiPc‐NiO4) nanosheets linked by nickel‐catecholate, which can be employed as highly efficient electrocatalysts for the CO2RR to CO. The obtained NiPc‐NiO4 has a good conductivity and exhibited a very high selectivity of 98.4 % toward CO production and a large CO partial current density of 34.5 mA cm−2, outperforming the reported MOF catalysts. This work highlights the potential of conductive crystalline frameworks in electrocatalysis.
Nickel phthalocyanine molecules as active sites were installed into nickel‐catecholate‐linked 2D conductive metal–organic framework nanosheets for efficient CO2 electroreduction with nearly 100 % CO selectivity.
The electroreduction of CO2 to value‐added chemicals such as CO is a promising approach to realize carbon‐neutral energy cycle, but still remains big challenge including low current density. Covalent ...organic frameworks (COFs) with abundant accessible active single‐sites can offer a bridge between homogeneous and heterogeneous electrocatalysis, but the low electrical conductivity limits their application for CO2 electroreduction reaction (CO2RR). Here, a 2D conductive Ni‐phthalocyanine‐based COF, named NiPc‐COF, is synthesized by condensation of 2,3,9,10,16,17,23,24‐octa‐aminophthalocyaninato Ni(II) and tert‐butylpyrene‐tetraone for highly efficient CO2RR. Due to its highly intrinsic conductivity and accessible active sites, the robust conductive 2D NiPc‐COF nanosheets exhibit very high CO selectivity (>93%) in a wide range of the applied potentials of −0.6 to −1.1 V versus the reversible hydrogen electrode (RHE) and large partial current density of 35 mA cm−2 at −1.1 V versus RHE in aqueous solution that surpasses all the conventional COF electrocatalysts. The robust NiPc‐COF that is bridged by covalent pyrazine linkage can maintain its CO2RR activity for 10 h. This work presents the implementation of the conductive COF nanosheets for CO2RR and provides a strategy to enhance energy conversion efficiency in electrocatalysis.
A conductive nickelophthalocyanine‐based 2D covalent organic framework is synthesized and employed as a robust and efficient electrocatalyst for CO2 electroreduction reaction, providing a new route to design highly efficient porous framework materials for the enhanced electrocatalysis via improving electrical conductivity.
This paper attempts to examine if the “strong” version of Porter Hypothesis is supported in China by investigating how different regulatory instruments and the relative stringency impact “green” ...productivity. We use a slacks-based measure (SBM) and Luenberger Productivity Index, accounting for undesirable outputs, to evaluate the industrial “green” productivity growth rates of China's 30 provinces. The estimates imply an unsustainable development model in China with significant regional differences. By employing a panel threshold model and a province-level panel dataset during 2000–2012, empirical results show that both command-and-control and market-based regulation have a non-linear relationship with and can be positively related to “green” productivity but with different constrains on regulation stringency: there are double thresholds with the command-and-control and exists an optimal range of stringency for productivity improvement; while a single threshold has been found with the market-based regulation and its current stringency is reasonable for most of provinces. Moreover, based on China's reality, the productivity effect driven by market-based regulation is much stronger than that of the command-and-control. The mechanism of informal regulation is much more complicated. Consequently, we find evidence to support the “strong” Porter Hypothesis that reasonable stringency of environmental regulations may enhance rather than lower industrial competitiveness.
•Examine the “strong” version of Porter Hypothesis in the case of China•Environmental total factor productivity accounting for undesirable outputs•The command-and-control, market-based and informal environmental regulation•Investigate the non-linear relationship between regulation and “green” productivity•The fixed-effect panel threshold model
Long-Term Efficacy of a Hepatitis E Vaccine Zhang, Jun; Zhang, Xue-Feng; Huang, Shou-Jie ...
The New England journal of medicine,
03/2015, Letnik:
372, Številka:
10
Journal Article
Recenzirano
Odprti dostop
Hepatitis E virus is a common cause of illness worldwide and is associated with severe complications, especially in pregnant women. In this report, the long-term efficacy, immunogenicity, and safety ...of a hepatitis E vaccine are described.
Hepatitis E virus (HEV) is a common cause of acute hepatitis worldwide.
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HEV infection occurs in two distinct epidemiologic patterns.
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The most common pattern is waterborne infection, which is caused by HEV genotype 1 or 2 and occurs mainly in resource-limited countries, often in large, protracted outbreaks or in sporadic cases associated with high mortality among pregnant women.
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The other pattern is transmission from animals and humans, which is caused by HEV genotype 3 or 4 and occurs widely in both resource-limited and developed countries.
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Rein et al.
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estimated the incidence of hepatitis E in areas . . .
Charge redistribution on surface of Ru nanoparticle can significantly affect electrocatalytic HER activity. Herein, a double atomic‐tuned RuBi SAA/Bi@OG nanostructure that features RuBi single‐atom ...alloy nanoparticle supported by Bi−O single‐site‐doped graphene was successfully developed by one‐step pyrolysis method. The alloyed Bi single atom and adjacent Bi−O single site in RuBi SAA/Bi@OG can synergistically manipulate electron transfer on Ru surface leading to optimum charge redistribution. Thus, the resulting RuBi SAA/Bi@OG exhibits superior alkaline HER activity. Its mass activity is up to 65000 mA mg−1 at an overpotential of 150 mV, which is 72.2 times as much as that of commercial Pt/C. DFT calculations reveal that the RuBi SAA/Bi@OG possesses the optimum charge redistribution, which is most beneficial to strengthen adsorption of water and weaken hydrogen‐adsorption free energy in HER process. This double atomic‐tuned strategy on surface charge redistribution of Ru nanoparticle opens a new way to develop highly efficient electrocatalysts.
A double atomic‐tuned RuBi SAA/Bi@OG nanostructure was prepared by one‐step pyrolysis method. The electron density on surface of Ru nanoparticle can be synergistically modulated by alloyed Bi single atom and adjacent Bi−O single site leading to optimum charge redistribution. Thus, the resulting RuBi SAA/Bi@OG exhibits superior alkaline HER activity.
Designing and fabrication of highly active single-atom catalysts (SACs) with maximized atomic efficiency is highly desirable but still remains a great challenge. Herein, highly active and stable ...cobalt single-atoms with a Co–N 4 moiety were uniformly anchored on a porous porphyrinic triazine-based framework (CoSAs/PTF) by a simple ionothermal method. Due to the abundant single-atom Co–N 4 species, the hierarchical porous structure and the good conductivity, the resultant catalyst is highly active for the electrocatalytic oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER). For the ORR, a more positive half-wave potential of 0.808 V ( vs. RHE) was achieved, compared with commercial benchmark Pt/C (0.806 V). Furthermore, a small onset potential of 21 mV and a low Tafel slope of 50 mV per decade were obtained for the HER. The porphyrin-like structure was found to stabilize the CoSAs effectively, thus leading to long-term durability and a remarkable methanol-tolerant behavior. This bifunctional single-atom catalyst might be a promising candidate to replace Pt-based electrocatalysts in electrolysers and fuel cells.
The efficacy of osimertinib was compromised by the development of resistance mechanisms, such as EGFR C797S. In vitro study proved that cells harboring EGFR C797S in trans with T790M are sensitive to ...a combination of first- and third-generation EGFR tyrosine kinase inhibitors. However, this has not been reported clinically.
We performed capture-based sequencing on longitudinal plasma samples obtained at various treatment milestones from a patient with advanced lung adenocarcinoma who was undergoing targeted therapy.
At the development of resistance to osimertinib, the patient’s plasma sample revealed EGFR C797S located in trans with T790M. He achieved partial response accompanied by undetectable C797S after commencement of a combinatorial treatment consisting of erlotinib and osimertinib. After 3 months of progression-free survival, he experienced progressive disease with emergence of EGFR C797S located in cis to T790M.
We report the first clinical evidence of efficacy generated by combination therapy consisting of first- and third-generation EGFR tyrosine kinase inhibitors targeting concomitant EGFR T790M and C797S in trans. We also reveal that the clonal progression of C797S from in trans to in cis at disease progression may serve as a potential resistance mechanism.
Daunorubicin (DNR) is used clinically to treat acute myeloid leukemia (AML), while the signaling pathways associated with its cytotoxicity are not fully elucidated. Thus, we investigated the ...DNR‐induced death pathway in the human AML cell lines U937 and HL‐60. DNR‐induced apoptosis in U937 cells accompanied by downregulation of MCL1 and BCL2L1, upregulation of Phorbol‐12‐myristate‐13‐acetate‐induced protein 1 (NOXA), and mitochondrial depolarization. DNR induced NOX4‐mediated reactive reactive oxygen species (ROS) production, which in turn inactivated Akt and simultaneously activated p38 mitogen‐activated protein kinase (MAPK). Activated p38 MAPK and inactivated Akt coordinately increased GSK3β‐mediated cAMP response element‐binding protein (CREB) phosphorylation, which promoted NOXA transcription. NOXA upregulation critically increased the proteasomal degradation of MCL1 and BCL2L1. The same pathway was also responsible for the DNR‐induced death of HL‐60 cells. Restoration of MCL1 or BCL2L1 expression alleviated DNR‐induced mitochondrial depolarization and cell death. Furthermore, ABT‐199 (a BCL2 inhibitor) synergistically enhanced the cytotoxicity of DNR in AML cell lines. Notably, DNR‐induced DNA damage was not related to NOXA‐mediated degradation of MCL1 and BCL2L1. Collectively, these results indicate that the upregulation of NOXA expression through the NOX4‐ROS‐p38 MAPK‐GSK3β‐CREB axis results in the degradation of MCL1 and BCL2L1 in DNR‐treated U937 and HL‐60 cells. This signaling pathway may provide insights into the mechanism underlying DNR‐triggered apoptosis in AML cells.
Daunorubicin (DNR)‐induced NOX4‐mediated ROS generation activates p38 MAPK and inactivates Akt, which activates GSK3β by phosphorylation of Y216 and dephosphorylation of S9. GSK3β‐mediated CREB phosphorylation promotes NOXA transcription in U937 and HL‐60 cells. NOXA upregulation elicits MCL1 and BCL2L1 degradation, resulting in the activation of caspase‐3 and apoptosis of U937 and HL‐60 cells.
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