The introduction of micropores, reconstruction defects, and heteroatoms into monolayer graphene has been realized by utilizing photon energy in the ultraviolet (UV) region and reactive oxygen ...species. The defect density of monolayer graphene has been analyzed via the Raman spectral D/G intensity ratio, and the UV emission intensity near the graphene surface has been evaluated for varying oxygen concentrations. These investigations have shown that the reactive oxygen species dissociated from ozone efficiently influence the formation of defects in monolayer graphene, which can be controlled by the oxygen concentration under UV irradiation. The effective defect formation and heteroatom doping obtained by UV irradiation have been demonstrated by scanning transmission electron microscopy with electron energy-loss spectroscopy (STEM–EELS). Finally, in defect formation due to UV irradiation under an oxygen atmosphere, it has been demonstrated that the conductivity of defective graphene is maintained at the same level as pristine graphene because defects, such as vacancy-type and reconstructed-type defects, behave as adsorption sites, resulting in a hole doping effect from oxygen atoms or molecules.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
To assess the potential of pepper mild mottle virus (PMMoV) as a viral process indicator, its reduction through coagulation–sedimentation (CS) and rapid sand filtration (RSF) were compared with those ...of Escherichia coli, previously used viral indicators, and norovirus genotype II (NoV GII; enteric virus reference pathogen) in a bench-scale experiment. PMMoV log10 reductions in CS (1.96 ± 0.30) and RSF (0.26 ± 0.38) were similar to those of NoV GII (1.86 ± 0.61 and 0.28 ± 0.46). PMMoV, the most abundant viruses in the raw water, was also determined during CS, RSF, and advanced treatment processes at two full-scale drinking water treatment plants under strict turbidity management over a 13-month period. PMMoV was concentrated from large-volume water samples (10–614 L) and quantified by Taqman-based quantitative polymerase chain reaction. The PMMoV log10 reduction in CS (2.38 ± 0.74, n = 13 and 2.63 ± 0.76, n = 10 each for Plant A and B) and in ozonation (1.91 ± 1.18, n = 5, Plant A) greatly contributed to the overall log10 reduction. Our results suggest that PMMoV can act as a useful treatment process indicator of enteric viruses and can be used to monitor the log10 reduction of individual treatment processes at drinking water treatment plants due to its high and consistent copy numbers in source water.
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•Log10 reduction of PMMoV was similar to NoV GII in bench-scale rapid sand filtration.•Indigenous PMMoV was abundant in raw water source throughout the year.•Indigenous virus was successfully concentrated and detected from >500 L of water.•Coagulation–sedimentation and ozonation largely contributed to virus reduction at DWTP.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
High throughput synthesis of atomic layer graphene membrane by chemical vapor deposition (CVD) is one of key technologies to establish industrial applications. Here we report the details of the ...initial stage of graphene growth on copper substrate by radio frequency (RF) plasma-assisted CVD under low pressure and compare the nucleation rate and the growth rate with conventional thermal CVD. Two-dimensional growth rate of graphene by plasma-assisted CVD is 100 and 1000 times larger than that of thermal CVD at 950 °C and at 750 °C, respectively. It is found that graphene growth is governed by the diffusion of active carbon species on the copper surface with a very low activation energy of 0.4 eV at low-temperature(≦ 850 °C) and low pressure. The high growth rate of plasma-assisted CVD of graphene is discussed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
The mitophagy receptor Nix interacts with LC3/GABARAP proteins, targeting mitochondria into autophagosomes for degradation. Here we present evidence for phosphorylation-driven regulation of the ...Nix:LC3B interaction. Isothermal titration calorimetry and NMR indicate a ~100 fold enhanced affinity of the serine 34/35-phosphorylated Nix LC3-interacting region (LIR) to LC3B and formation of a very rigid complex compared to the non-phosphorylated sequence. Moreover, the crystal structure of LC3B in complex with the Nix LIR peptide containing glutamic acids as phosphomimetic residues and NMR experiments revealed that LIR phosphorylation stabilizes the Nix:LC3B complex via formation of two additional hydrogen bonds between phosphorylated serines of Nix LIR and Arg11, Lys49 and Lys51 in LC3B. Substitution of Lys51 to Ala in LC3B abrogates binding of a phosphomimetic Nix mutant. Functionally, serine 34/35 phosphorylation enhances autophagosome recruitment to mitochondria in HeLa cells. Together, this study provides cellular, biochemical and biophysical evidence that phosphorylation of the LIR domain of Nix enhances mitophagy receptor engagement.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Surface sites of extensively exposed basal planes of MoS2 monolayer nanosheets, prepared via BuLi exfoliation of MoS2, have been doped with transition metal atoms for the first time to produce 2D ...monolayer catalysts used for the electrochemical hydrogen evolution reaction (HER). Their HER activity is significantly higher than the corresponding thin and bulk MoS2 layers. HAADF-STEM images show direct proof that single transition metal atoms reside at the surface basal sites, which subtly modify the electro-catalytic activity of the monolayer MoS2, dependent on their electronic and stereospecific properties. It is found that these dopants play an important role in tuning the hydrogen adsorption enthalpies of the exposed surface S atoms and Mo atoms in HER. We report electrochemical testing, characterization and computational modelling and demonstrate that Co can significantly enhance the HER activity by the dominant Co–S interaction, whereas Ni substantially lowers the HER rate due to the Ni–Mo interaction at the same basal site. The two transition metal dopants show opposite doping behavior despite the fact that they are neighbors in the periodic table.
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IJS, KILJ, NUK, UL, UM, UPUK
α-Dystroglycan (α-DG) is a highly-glycosylated surface membrane protein. Defects in the O-mannosyl glycan of α-DG cause dystroglycanopathy, a group of congenital muscular dystrophies. The core M3 ...O-mannosyl glycan contains tandem ribitol-phosphate (RboP), a characteristic feature first found in mammals. Fukutin and fukutin-related protein (FKRP), whose mutated genes underlie dystroglycanopathy, sequentially transfer RboP from cytidine diphosphate-ribitol (CDP-Rbo) to form a tandem RboP unit in the core M3 glycan. Here, we report a series of crystal structures of FKRP with and without donor (CDP-Rbo) and/or acceptor RboP-(phospho-)core M3 peptide substrates. FKRP has N-terminal stem and C-terminal catalytic domains, and forms a tetramer both in crystal and in solution. In the acceptor complex, the phosphate group of RboP is recognized by the catalytic domain of one subunit, and a phosphate group on O-mannose is recognized by the stem domain of another subunit. Structure-based functional studies confirmed that the dimeric structure is essential for FKRP enzymatic activity.
The spatial resolutions of even the most sensitive isotope analysis techniques based on light or ion probes are limited to a few hundred nanometres. Although vibrational spectroscopy using electron ...probes has achieved higher spatial resolution
, the detection of isotopes at the atomic level
has been challenging so far. Here we show the unambiguous isotopic imaging of
C carbon atoms embedded in
C graphene and the monitoring of their self-diffusion via atomic-level vibrational spectroscopy. We first grow a domain of
C carbon atoms in a pre-existing crack of
C graphene, which is then annealed at 600 degrees Celsius for several hours. Using scanning transmission electron microscopy-electron energy loss spectroscopy, we obtain an isotope map that confirms the segregation of
C atoms that diffused rapidly. The map also indicates that the graphene layer becomes isotopically homogeneous over 100-nanometre regions after 2 hours. Our results demonstrate the high mobility of carbon atoms during growth and annealing via self-diffusion. This imaging technique can provide a fundamental methodology for nanoisotope engineering and monitoring, which will aid in the creation of isotope labels and tracing at the nanoscale.
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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
Ammonia is regarded as an energy vector for hydrogen storage, transport and utilization, which links to usage of renewable energies. However, efficient catalysts for ammonia decomposition and their ...underlying mechanism yet remain obscure. Here we report that atomically-dispersed Ru atoms on MgO support on its polar (111) facets {denoted as MgO(111)} show the highest rate of ammonia decomposition, as far as we are aware, than all catalysts reported in literature due to the strong metal-support interaction and efficient surface coupling reaction. We have carefully investigated the loading effect of Ru from atomic form to cluster/nanoparticle on MgO(111). Progressive increase of surface Ru concentration, correlated with increase in specific activity per metal site, clearly indicates synergistic metal sites in close proximity, akin to those bimetallic N
complexes in solution are required for the stepwise dehydrogenation of ammonia to N
/H
, as also supported by DFT modelling. Whereas, beyond surface doping, the specific activity drops substantially upon the formation of Ru cluster/nanoparticle, which challenges the classical view of allegorically higher activity of coordinated Ru atoms in cluster form (B
sites) than isolated sites.
Objectives
To investigate the incidence and risk factors of postoperative delirium among patients aged ≥65 years undergoing elective urological surgery.
Methods
From April 2015 through December 2016, ...1023 consecutive patients aged ≥65 years who received transurethral, laparoscopic (with or without robot assistance) or open surgery in eight institutions were enrolled in this prospective observational study. Their preoperative cognitive status was assessed with the Hasegawa Dementia Scale‐Revised score. The treating physician or nurse assessed delirium using the Intensive Care Delirium Screening Checklist. Multivariate logistic regression analysis was used to determine predictive factors for postoperative delirium.
Results
We analyzed 946 patients whose median age was 74 years (range 65–95 years). Postoperative delirium was observed in 32 patients (3.4%). Multivariate analysis showed that a history of cerebrovascular disease (odds ratio 5.24, 95% confidence interval 2.05–13.40), low Hasegawa Dementia Scale‐Revised score <20 points (odds ratio 3.50, 95% confidence interval 1.36–9.02), low serum albumin level <3.5 g/dL (odds ratio 3.12, 95% confidence interval 1.25–7.83) and long surgery duration >4 h (odds ratio 4.94, 95% confidence interval 2.20–11.10) were independent risk factors for the development of postoperative delirium.
Conclusions
The preoperative medical history, cognitive status, low serum albumin level and operative duration were associated with the development of postoperative delirium, although the incidence was just 3.4% in elective urological surgery. The present results suggest that the Hasegawa Dementia Scale‐Revised is a useful tool for assessment of the risk for delirium.
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BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK
Issues regarding the structural diversity (heterogeneity) of an antibody molecule have been the subject of discussion along with the development of antibody drugs. Research on heterogeneity has been ...extensive in recent years, but no clear solution has been reached. Heterogeneity is also observed in catalytic antibody k light chains (CLs). In this study, we investigated how the constant region domain of CLs concerns structural diversity because it is a simple and good example for elucidating heterogeneity. By means of cation‐exchange chromatography, SDS‐PAGE, and 2‐dimensional electrophoresis for the CL, multimolecular forms consisting of different electrical charges and molecular sizes coexisted in the solution, resulting in the similar heterogeneity of the full length of CLs. The addition of copper ion could cause the multimolecular forms to change to monomolecular forms. Copper ion contributed greatly to the enrichment of the dimer form of CL and the homogenization of the differently charged CLs. Two molecules of the CL protein bound one copper ion. The binding affinity of the ion was 48.0 μM21. Several divalent metal ions were examined, but only zinc showed a similar effect. —Hifumi, E., Taguchi, H., Kato, R., Uda, T. Role of the constant region domain in the structural diversity of human antibody light chains. FASEB J. 31, 1668–1677 (2017) www.fasebj.org
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
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