I13-2-Diamond Manchester Imaging
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Open Access
Abstract: This study extensively investigates the influence of different pyrolysis temperatures and organic matter contents on the fluid flow and heat transfer properties in oil shale samples. Utilizing CT images to generate three-dimensional digital rock, coupled simulations of CO2 flow and heat transfer were conducted, analyzing parameters such as velocity fields, permeability, temperature fields, average temperatures, and heat transfer coefficients. The results reveal that, for relatively homogeneous oil shale samples, the permeability exhibits a monotonous increase with rising pyrolysis temperature. While the effect of pyrolysis temperature on the distribution characteristics of velocity and temperature fields is minimal, it significantly impacts the heat transfer coefficients. Specifically, the heat transfer coefficients increase significantly in the direction perpendicular to the bedding plane, while they decrease or remain unchanged parallel to it. Additionally, the organic matter content significantly influences the fluid flow and heat transfer properties of shale samples. After undergoing heat treatment, the heterogeneity of pore structures in shale samples varies significantly, affecting the characteristics of fluid flow and heat transfer. The influence of organic matter content and pyrolysis temperature on fluid flow and heat transfer in shale primarily stems from the effect of organic matter pyrolysis on the original pore structure. The development and connectivity of pore networks are closely related to the distribution characteristics of the original organic matter and are not directly correlated with the organic matter content. These findings provide essential theoretical guidance and technical support for the development and utilization of oil shale resources, while also offering valuable references and insights for future research.
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Aug 2024
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I03-Macromolecular Crystallography
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Yao
Zhou
,
Kaizhou
Yan
,
Qijian
Qin
,
Olawale G.
Raimi
,
Chao
Du
,
Bin
Wang
,
Chukwuemeka Samson
Ahamefule
,
Bartosz
Kowalski
,
Cheng
Jin
,
Daniel M. F.
Van Aalten
,
Wenxia
Fang
Diamond Proposal Number(s):
[26793]
Open Access
Abstract: Aspergillus fumigatus is a devastating opportunistic fungal pathogen causing hundreds of thousands of deaths every year. Phosphoglucose isomerase (PGI) is a glycolytic enzyme that converts glucose-6-phosphate to fructose-6-phosphate, a key precursor of fungal cell wall biosynthesis. Here, we demonstrate that the growth of A. fumigatus is repressed by the deletion of pgi, which can be rescued by glucose and fructose supplementation in a 1:10 ratio. Even under these optimized growth conditions, the Δpgi mutant exhibits severe cell wall defects, retarded development, and attenuated virulence in Caenorhabditis elegans and Galleria mellonella infection models. To facilitate exploitation of A. fumigatus PGI as an antifungal target, we determined its crystal structure, revealing potential avenues for developing inhibitors, which could potentially be used as adjunctive therapy in combination with other systemic antifungals.
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Aug 2022
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B22-Multimode InfraRed imaging And Microspectroscopy
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Xinchen
Kang
,
Bin
Wang
,
Kui
Hu
,
Kai
Lyu
,
Xue
Han
,
Ben F.
Spencer
,
Mark D.
Frogley
,
Floriana
Tuna
,
Eric J. L.
Mcinnes
,
Robert A. W.
Dryfe
,
Buxing
Han
,
Sihai
Yang
,
Martin
Schroeder
Diamond Proposal Number(s):
[19171]
Open Access
Abstract: Efficient electro-reduction of CO2 over metal–organic framework (MOF) materials is hindered by the poor contact between thermally synthesized MOF particles and the electrode surface, which leads to low Faradaic efficiency for a given product and poor electrochemical stability of the catalyst. We report a MOF-based electrode prepared via electro-synthesis of MFM-300(In) on an indium foil, and its activity for the electrochemical reduction of CO2 is assessed. The resultant MFM-300(In)-e/In electrode shows a 1 order of magnitude improvement in conductivity compared with that for MFM-300(In)/carbon-paper electrodes. MFM-300(In)-e/In exhibits a current density of 46.1 mA cm–2 at an applied potential of −2.15 V vs Ag/Ag+ for the electro-reduction of CO2 in organic electrolyte, achieving an exceptional Faradaic efficiency of 99.1% for the formation of formic acid. The facile preparation of the MFM-300(In)-e/In electrode, coupled with its excellent electrochemical stability, provides a new pathway to develop efficient electro-catalysts for CO2 reduction.
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Sep 2020
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Isabel C.
De Freitas
,
Luanna S.
Parreira
,
Eduardo C. M.
Barbosa
,
Barbara A.
Novaes
,
Tong
Mou
,
Tiago. V.
Alves
,
Jhon
Quiroz
,
Yi-Chi
Wang
,
Thomas J.
Slater
,
Andrew
Thomas
,
Bin
Wang
,
Sarah J.
Haigh
,
Pedro H. C.
Camargo
Open Access
Abstract: We develop herein plasmonic–catalytic Au–IrO2 nanostructures with a morphology optimized for efficient light harvesting and catalytic surface area; the nanoparticles have a nanoflower morphology, with closely spaced Au branches all partially covered by an ultrathin (1 nm) IrO2 shell. This nanoparticle architecture optimizes optical features due to the interactions of closely spaced plasmonic branches forming electromagnetic hot spots, and the ultra-thin IrO2 layer maximizes efficient use of this expensive catalyst. This concept was evaluated towards the enhancement of the electrocatalytic performances towards the oxygen evolution reaction (OER) as a model transformation. The OER can play a central role in meeting future energy demands but the performance of conventional electrocatalysts in this reaction is limited by the sluggish OER kinetics. We demonstrate an improvement of the OER performance for one of the most active OER catalysts, IrO2, by harvesting plasmonic effects from visible light illumination in multimetallic nanoparticles. We find that the OER activity for the Au–IrO2 nanoflowers can be improved under LSPR excitation, matching best properties reported in the literature. Our simulations and electrocatalytic data demonstrate that the enhancement in OER activities can be attributed to an electronic interaction between Au and IrO2 and to the activation of Ir–O bonds by LSPR excited hot holes, leading to a change in the reaction mechanism (rate-determinant step) under visible light illumination.
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Apr 2020
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B22-Multimode InfraRed imaging And Microspectroscopy
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Xinchen
Kang
,
Kai
Lyu
,
Lili
Li
,
Jiangnan
Li
,
Louis
Kimberley
,
Bin
Wang
,
Lifei
Liu
,
Yongqiang
Cheng
,
Mark D.
Frogley
,
Svemir
Rudic
,
Anibal J.
Ramirez-Cuesta
,
Robert A. W.
Dryfe
,
Buxing
Han
,
Sihai
Yang
,
Martin
Schroder
Diamond Proposal Number(s):
[19171]
Open Access
Abstract: Incorporation of mesopores and active sites into metal-organic framework (MOF) materials to uncover new efficient catalysts is a highly desirable but challenging task. We report the first example of a mesoporous MOF obtained by templated electrosynthesis using an ionic liquid as both electrolyte and template. The mesoporous Cu(II)-MOF MFM-100 has been synthesised in 100 seconds at room temperature, and this material incorporates crystal defects with uncoupled Cu(II) centres as evidenced by confocal fluorescence microscopy and electron paramagnetic resonance spectroscopy. MFM-100 prepared in this way shows exceptional catalytic activity for the aerobic oxidation of alcohols to produce aldehydes in near quantitative yield and selectivity under mild conditions, as well as having excellent stability and reusability over repeated cycles. The catalyst-substrate binding interactions have been probed by inelastic neutron scattering. This study offers a simple strategy to create mesopores and active sites simultaneously via electrochemical formation of crystal defects to promote efficient catalysis using MOFs.
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Oct 2019
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I09-Surface and Interface Structural Analysis
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Ao
Yang
,
Antoni
Franco Canellas
,
Mikio
Sato
,
Bin
Wang
,
Rong-Bin
Wang
,
Harunobu
Koike
,
Ingo
Salzmann
,
Pardeep
Kumar Thakur
,
Tien-Lin
Lee
,
Lijia
Liu
,
Satoshi
Kera
,
Alexander
Gerlach
,
Kaname
Kanai
,
Jian
Fan
,
Frank
Schreiber
,
Steffen
Duhm
Diamond Proposal Number(s):
[9523]
Abstract: We investigated the structural and electronic properties of vacuum sublimed 7,8,15,16-tetraazaterrylene (TAT) thin films on Au(111), Ag(111), and Cu(111) substrates using inverse photoemission spectroscopy, ultraviolet photoelectron spectroscopy (UPS), x-ray photoelectron spectroscopy (XPS), low energy electron diffraction (LEED), and the x-ray standing wave (XSW) technique. The LEED reveals a flat adsorption geometry of the monolayer TAT on these three substrates, which is in accordance with the XSW results. The molecules are slightly distorted in monolayers on all three substrates with the nitrogen atoms having smaller averaged bonding distances than the carbon atoms. On Ag(111) and Cu(111), chemisorption with a net electron transfer from the substrate to the adsorbate takes place, as evidenced by UPS and XPS. Combining these results, we gain full insight into the correlation between electronic properties and interface geometry.
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Oct 2016
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I09-Surface and Interface Structural Analysis
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Peter
Deimel
,
Reda M.
Bababrik
,
Bin
Wang
,
Philip
Blowey
,
Luke
Rochford
,
Pardeep K.
Thakur
,
Tien-Lin
Lee
,
Marie-Laure
Bocquet
,
Johannes V.
Barth
,
Phil
Woodruff
,
David
Duncan
,
Francesco
Allegretti
Diamond Proposal Number(s):
[8940]
Open Access
Abstract: The strong parallels between coordination chemistry and adsorption on metal surfaces, with molecules and ligands forming local bonds to individual atoms within a metal surface, have been established over many years of study. The recently proposed “surface trans-effect” (STE) appears to be a further manifestation of this analogous behaviour, but so far the true nature of the modified molecule–metal surface bonding has been unclear. The STE could play an important role in determining the reactivities of surface-supported metal–organic complexes, influencing the design of systems for future applications. However, the current understanding of this effect is incomplete and lacks reliable structural parameters with which to benchmark theoretical calculations. Using X-ray standing waves, we demonstrate that ligation of ammonia and water to iron phthalocyanine (FePc) on Ag(111) increases the adsorption height of the central Fe atom; dispersion corrected density functional theory calculations accurately model this structural effect. The calculated charge redistribution in the FePc/H2O electronic structure induced by adsorption shows an accumulation of charge along the σ-bonding direction between the surface, the Fe atom and the water molecule, similar to the redistribution caused by ammonia. This apparent σ-donor nature of the observed STE on Ag(111) is shown to involve bonding to the delocalised metal surface electrons rather than local bonding to one or more surface atoms, thus indicating that this is a true surface trans-effect.
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Jun 2016
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I03-Macromolecular Crystallography
I04-1-Macromolecular Crystallography (fixed wavelength)
I04-Macromolecular Crystallography
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Jason B.
Cross
,
Jing
Zhang
,
Qingyi
Yang
,
Michael F.
Mesleh
,
Jan Antoinette C.
Romero
,
Bin
Wang
,
Doug
Bevan
,
Katherine M.
Poutsiaka
,
Felix
Epie
,
Terence
Moy
,
Anu
Daniel
,
Joseph
Shotwell
,
Brian
Chamberlain
,
Nicole
Carter
,
Ole
Andersen
,
John
Barker
,
M. Dominic
Ryan
,
Chester A.
Metcalf
,
Jared
Silverman
,
Kien
Nguyen
,
Blaise
Lippa
,
Roland E.
Dolle
Abstract: The ATPase subunit of DNA gyrase B is an attractive antibacterial target due to high conservation across bacteria and the essential role it plays in DNA replication. A novel class of pyrazolopyridone inhibitors was discovered by optimizing a fragment screening hit scaffold using structure guided design. These inhibitors show potent Gram-positive antibacterial activity and low resistance incidence against clinically important pathogens
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Feb 2016
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I04-1-Macromolecular Crystallography (fixed wavelength)
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Qian
Wu
,
Atanu
Paul
,
Dan
Su
,
Shahid
Mehmood
,
Tzeh keong
Foo
,
Takashi
Ochi
,
Emma l.
Bunting
,
Bing
Xia
,
Carol v
Robinson
,
Bin
Wang
,
Tom l.
Blundell
Open Access
Abstract: BRCA1 accumulation at DNA damage sites is an important step for its function in the DNA damage response and in DNA repair. BRCA1-BRCT domains bind to proteins containing the phosphorylated serine-proline-x-phenylalanine (pSPxF) motif including Abraxas, Bach1/FancJ, and CtIP. In this study, we demonstrate that ionizing radiation (IR)-induces ATM-dependent phosphorylation of serine 404 (S404) next to the pSPxF motif. Crystal structures of BRCT/Abraxas show that phosphorylation of S404 is important for extensive interactions through the N-terminal sequence outside the pSPxF motif and leads to formation of a stable dimer. Mutation of S404 leads to deficiency in BRCA1 accumulation at DNA damage sites and cellular sensitivity to IR. In addition, two germline mutations of BRCA1 are found to disrupt the dimer interface and dimer formation. Thus, we demonstrate a mechanism involving IR-induced phosphorylation and dimerization of the BRCT/Abraxas complex for regulating Abraxas-mediated recruitment of BRCA1 in response to IR.
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Jan 2016
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I03-Macromolecular Crystallography
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Jing
Zhang
,
Qingyi
Yang
,
Jason B.
Cross
,
Jan Antoinette C.
Romero
,
Katherine M.
Poutsiaka
,
Felix
Epie
,
Douglas
Bevan
,
Bin
Wang
,
Yanzhi
Zhang
,
Ajit
Chavan
,
Xin
Zhang
,
Terence
Moy
,
Anu
Daniel
,
Kien
Nguyen
,
Brian
Chamberlain
,
Nicole
Carter
,
Joseph
Shotwell
,
Jared
Silverman
,
Chester A.
Metcalf
,
Dominic
Ryan
Abstract: The emergence and spread of multidrug resistant bacteria are widely believed to endanger human health. New drug targets and lead compounds exempt from cross-resistance with existing drugs are urgently needed. We report on the discovery of azaindole ureas as a novel class of bacterial gyrase B inhibitors and detail the story of their evolution from a de novo design hit based on structure-based drug design. These inhibitors show potent minimum inhibitory concentrations against fluoroquinolone resistant MRSA and other Gram-positive bacteria.
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Oct 2015
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