bluuebunny/crossref_metadata_2025_split huggingface dataset:
Toluene 4‐Monooxygenase Reaction Intermediates
Authors: Acheson Justin F , Bailey Lucas J , Brunold Thomas C , Fox Brian G 
Published: March 2020

Abstract

Toluene 4‐monooxygenase (T4MO) is a four‐protein diiron enzyme complex that catalyzes the regiospecific oxidation of toluene to
p
‐cresol. Earlier high‐resolution crystal structures of the stoichiometric complex of hydroxylase and effector protein (T4moHD) revealed how protein–protein interactions and reduction of the diferric center produce an active site configuration poised for reaction with O
2
. In this article, additional crystal structures are described for the reductase (T4moF), a complex between the hydroxylase and the Rieske‐type ferredoxin (T4moHC), and the complex of hydroxylase and effector protein reacted with various combinations of H
2
O
2
, O
2
, and toluene;
p
‐cresol was added to the diferric enzyme or produced by catalytic turnover in the crystal. The structure of a catalytically competent arylperoxo Fe
2+
/Fe
3+
species with delocalized aryl radical character, along with those of two unreactive peroxo species, provides new insight into enzymatic aromatic ring hydroxylation, including the role of active site water molecules and how proton transfer mediated by a carboxylate shift may trigger catalysis.
αKG‐Dependent Enzyme
AndA
Involved in Anditomin Biosynthesis
Authors: Nakashima Yu , Mori Takahiro , Abe Ikuro 
Published: March 2020

Abstract

Oxidative modification reactions catalyzed by Fe(II)/α‐ketoglutarate (αKG)‐dependent dioxygenases are widely observed in the primary and secondary metabolic pathways. The members of this dioxygenase superfamily catalyze a variety of reactions, including hydroxylation, epimerization, desaturation, epoxidation, ring construction, and ring expansion. In particular, the dynamic skeletal rearrangement reactions by Fe(II)/αKG‐dependent dioxygenases are prevalent in fungal meroterpenoid biosynthesis. These reactions proceed
via
intramolecular radical transfer reactions, which are initiated by the abstraction of a hydrogen atom from the substrate with an activated Fe(IV)‐oxo species. In this article, we introduce the multifunctional enzyme AndA, in the biosynthetic pathway of the fungal meroterpenoid anditomin. AndA catalyzes unusual two‐step enzyme reactions to construct the bicyclo[2.2.2]octane system of anditomin. Crystallographic studies revealed that the multi‐step enzyme reaction occurs in the same active site, where the position of the initial hydrogen atom abstraction is enzymatically controlled by the binding mode of the substrates. The detailed catalytic mechanism of AndA is proposed, based on the crystal structures, mutagenesis analysis, and computational studies.
Recommendations of megavoltage computed tomography settings for the implementation of adaptive radiotherapy on helical tomotherapy units
Authors: Velten Christian , Boyd Robert , Jeong Kyoungkeun , Garg Madhur K. , Tomé Wolfgang A. 
Published: March 2020

AbstractMegavoltage computed tomography (MVCT) image quality metrics were evaluated on an Accuray Radixact unit to recommend scan settings for the implementation of a consistent adaptive radiotherapy program. Megavoltage computed tomography image quality was evaluated and compared to a kilovoltage CT (kVCT) simulator using a commercial cone beam computed tomography image quality phantom. Megavoltage computed tomographies were acquired on the Accuray Radixact using fine, normal, and coarse pitches, with all available reconstruction slice thicknesses, each of which were reconstructed using standard and iterative reconstruction (IR). Image quality metrics (IQM) were evaluated using DoseLab: automatically and manually calculated spatial resolution, subject contrast, and contrast‐to‐noise ratio (CNR). Scanning time was 15.6 s/cm for fine, 8.1 s/cm for normal, and 5.6 s/cm for coarse pitch. Automatically evaluated spatial resolutions ranged from 0.39, 0.41, to 0.42 lp/mm for standard reconstruction and from 0.24, 0.21, to 0.18 lp/mm for soft‐tissue IR, respectively, with general IR yielding values in between these. Spatial resolution for kVCT was measured to be at least 0.42 lp/mm. Contrast was consistent across MVCT settings with 8.1 ± 0.2%, while kVCT contrast was 10.27 ± 0.05%. CNR was calculated to be 3.3 ± 0.4 for standard reconstruction, 7.4 ± 0.4 for general IR, and 12.0 ± 1.9 for soft‐tissue IR. It was found that increasing reconstruction slice thickness for a given pitch does not improve IQMs. Based on the consistency of contrast metrics across pitch values and the only slightly reduced spatial resolution using normal compared to fine pitch, we recommend the use of normal pitch with 2 mm slice thickness to maximize image quality for ART while limiting scanning time. Only for sites for which improved CNR is required and reduced spatial resolution is acceptable, soft‐tissue IR is recommended.
Loss of ap4s1 in zebrafish leads to neurodevelopmental defects resembling spastic paraplegia 52
Authors: D’Amore Angelica , Tessa Alessandra , Naef Valentina , Bassi Maria Teresa , Citterio Andrea , Romaniello Romina , Fichi Gianluca , Galatolo Daniele , Mero Serena , Battini Roberta , Bertocci Giulia , Baldacci Jacopo , Sicca Federico , Gemignani Federica , Ricca Ivana , Rubegni Anna , Hirst Jennifer , Marchese Maria , Sahin Mustafa , Ebrahimi‐Fakhari Darius , Santorelli Filippo M. 
Published: March 2020

AbstractAutosomal recessive spastic paraplegia 52 is caused by biallelic mutations in AP4S1 which encodes a subunit of the adaptor protein complex 4 (AP‐4). Using next‐generation sequencing, we identified three novel unrelated SPG52 patients from a cohort of patients with cerebral palsy. The discovered variants in AP4S1 lead to reduced AP‐4 complex formation in patient‐derived fibroblasts. To further understand the role of AP4S1 in neuronal development and homeostasis, we engineered the first zebrafish model of AP‐4 deficiency using morpholino‐mediated knockdown of ap4s1. In this model, we discovered several phenotypes mimicking SPG52, including altered CNS development, locomotor deficits, and abnormal neuronal excitability.
Most Appropriate Conventional Disease‐Modifying Antirheumatic Drug to Combine With Different Advanced Therapies in Rheumatoid Arthritis: A Systematic Literature Review With Meta‐Analysis
Authors: Decarriere Guillaume , Barnetche Thomas , Combe Bernard , Gaujoux-Viala Cécile , Lukas Cédric , Morel Jacques , Daien Claire 
Published: March 2020

ObjectiveIn rheumatoid arthritis, the association between advanced therapies (including biologic disease‐modifying antirheumatic drugs [DMARDs] and targeted synthetic DMARDs) and methotrexate (MTX) is recommended by international societies. When MTX cannot be used, other conventional synthetic DMARDs (csDMARDs) may be proposed. We aimed to compare the safety and efficacy of MTX and non‐MTX csDMARDs in combination with advanced therapies.MethodsWe systematically searched the literature for studies comparing the effectiveness, retention rate, and safety of MTX versus non‐MTX csDMARDs (leflunomide or others) in combination with tumor necrosis factor inhibitors (TNFi), abatacept, rituximab, tocilizumab, and JAK inhibitors. Meta‐analysis was performed with RevMan, using an inverse variance approach with fixed or random‐effects models. Risk ratios (RRs) and 95% confidence intervals (95% CIs) were estimated.ResultsThe literature search revealed 3,842 articles; 41 studies were included for the systematic literature review and 21 for the meta‐analysis: 13 with TNFi, 3 with abatacept, and 5 with rituximab. For TNFi, the European Alliance of Associations for Rheumatology (EULAR) response at 6 months was lower for patients receiving non‐MTX csDMARDs than for those using MTX (RR 0.93 [95% CI 0.87, 1.0],P= 0.04; n = 3,843; I2= 28%), with a lower retention rate at 12 months. For abatacept, effectiveness and safety were similar between the 2 groups. For rituximab, a good EULAR response was higher with leflunomide than MTX (RR 1.38 [95% CI 1.13, 1.68],P= 0.001; n = 2,078; I2= 0%), with similar adverse event rates. Meta‐analysis for tocilizumab or JAK inhibitors could not be performed.ConclusionThe different csDMARDs seem safe and efficient to combine with advanced therapies in RA patients. Although MTX seems slightly superior to other csDMARDs in combination with TNFi, leflunomide might be superior to MTX in combination with rituximab.
Synthesis of a Counteranion‐Stabilized Bis(silylium) Ion
Authors: Wu Qian , Roy Avijit , Wang Guoqiang , Irran Elisabeth , Klare Hendrik F. T. , Oestreich Martin 
Published: March 2020

AbstractThe preparation of a molecule with two alkyl‐tethered silylium‐ion sites from the corresponding bis(hydrosilanes) by two‐fold hydride abstraction is reported. The length of the conformationally flexible alkyl bridge is crucial as otherwise the hydride abstraction stops at the stage of a cyclic bissilylated hydronium ion. With an ethylene tether, the open form of the hydronium‐ion intermediate is energetically accessible and engages in another hydride abstraction. The resulting bis(silylium) ion has been NMR spectroscopically and structurally characterized. Related systems based on rigid naphthalen‐n,m‐diyl platforms can only be converted into the dications when the positively charged silylium‐ion units are remote from each other (1,8 versus 1,5 and 2,6).
Devising Efficient Red‐Shifting Strategies for Bioimaging: A Generalizable Donor‐Acceptor Fluorophore Prototype
Authors: Chen Cheng , Fang Chong 
Published: March 2020

AbstractLong emission wavelengths, high fluorescence quantum yields (FQYs), and large Stokes shifts are highly desirable features for fluorescent probes in biological imaging. However, the current development of many fluorescent probes remains largely trial‐and‐error and lacks efficiency. Moreover, to achieve far‐red/near‐infrared emission, a significant extension in the
‐conjugation is usually adopted but accompanied by other drawbacks such as fluorescence loss. In this review, we discuss an effective red‐shifting strategy built upon the green fluorescent protein chromophore, which enables a synergistic tuning of both the electronic ground and excited states. This approach could shorten the path toward redder emission in comparison to the conventional intramolecular charge transfer (ICT) strategy. We envision that this spectroscopy and computation‐aided strategy may advance the noncanonical fluorescent protein design and be generalized to various fluorophore scaffolds for redder emission while preserving other superior properties such as high FQYs.
S‐Nitroso‐N‐acetylpenicillamine impregnated endotracheal tubes for prevention of ventilator‐associated pneumonia
Authors: Homeyer Katie H. , Singha Priyadarshini , Goudie Marcus J. , Handa Hitesh 
Published: March 2020

AbstractThe chances of ventilator‐associated pneumonia (VAP) increases 6–20 folds when an endotracheal tube (ETT) is placed in a patient. VAP is one of the most common hospital‐acquired infections and comprises 86% of the nosocomial pneumonia cases. This study introduces the idea of nitric oxide‐releasing ETTs (NORel‐ETTs) fabricated by the incorporation of the nitric oxide (NO) donor S‐nitroso‐N‐acetylpenicillamine (SNAP) into commercially available ETTs via solvent swelling. The impregnation of SNAP provides NO release over a 7‐day period without altering the mechanical properties of the ETT. The NORel‐ETTs successfully reduced the bacterial infection from a commonly found pathogen in VAP, Pseudomonas aeruginosa, by 92.72 ± 0.97% when compared with the control ETTs. Overall, this study presents the incorporation of the active release of a bactericidal agent in ETTs as an efficient strategy to prevent the risk of VAP.
Validation of EORTC, CUETO, and EAU risk stratification in prediction of recurrence, progression, and death of patients with initially non–muscle‐invasive bladder cancer (NMIBC): A cohort analysis
Authors: Jobczyk Mateusz , Stawiski Konrad , Fendler Wojciech , Różański Waldemar 
Published: March 2020

AbstractBrief Description: The results demonstrate that the European Organisation for Research and Treatment of Cancer (EORTC) scale provides the best recurrence and progression prediction in comparison with European Association of Urology (EAU) and Club Urologico Espanol de Tratamiento Oncologico (CUETO) risk scores among a mixed population of patients with non–muscle‐invasive bladder who were treated with, or without, Bacillus Calmette‐Guerin (BCG) and without any immediate postoperative chemotherapy. The study highlights the role of tumor diameter and extent in transition prediction.This retrospective cohort analysis of 322 patients with newly diagnosed non–muscle‐invasive bladder cancer (NMIBC) assesses the concordance and accuracy of predicting recurrence and progression by EAU‐recommended tools (EAU risk groups, EORTC, and CUETO). One‐year and five‐year c‐indices ranged from 0.55 to 0.66 for recurrence and from 0.72 to 0.82 for progression. AUCROC of predictions ranged from 0.46 for 1‐year recurrence risk based on CUETO groups, to 0.82 for 1‐year progression risk based on EAU risk groups. Diameter (HR: 1.91; 95% CI: 1.39‐2.61) and tumor extent (HR: 1.21; 95% CI: 1.01‐1.46 for recurrence; HR: 3.1; 95% CI: 1.40‐6.87 for progression) were shown to be significant predictors in multistate analysis. Lower accuracy of prediction was observed for patients treated with BCG maintenance immunotherapy. The EORTC model (overall c‐index c = 0.64; 95% CI: 0.61‐0.68) was superior to the EAU (P = .035; .62; 95% CI: 0.59‐0.66) and CUETO (P < .001; c = 0.53; 95% CI: 0.50‐0.56) models in predicting recurrence. The EORTC model (c = 0.82; 95% CI: 0.77‐0.86) also performed better than CUETO (P = .008; c = 0.73; 95% CI: 0.66‐0.81) but there was no sufficient evidence that it performed better than EAU (P = .572; c = 0.81; 95% CI: 0.77‐0.84) for predicting progression. EORTC and CUETO gave similar predictions for progression in BCG‐treated EAU high‐risk patients (P = .48). We share anonymized individual patient data. In conclusion, despite moderate accuracy, EORTC provided the best recurrence and progression prediction for a mixed population of patients treated with, or without BCG, and without immediate postoperative chemotherapy.
Eco‐Friendly Sugar‐Based Natural Deep Eutectic Solvents as Effective Electrolyte Solutions for Dye‐Sensitized Solar Cells
Authors: Boldrini Chiara Liliana , Manfredi Norberto , Perna Filippo Maria , Capriati Vito , Abbotto Alessandro 
Published: March 2020

AbstractDye‐sensitized solar cells containing sugar‐based natural deep eutectic solvents (NADESs) as active electrolyte solvents have been studied in terms of their photovoltaic (PV) properties, including main PV characteristics, incident photon‐to‐current efficiency, and impedance properties. Five monosaccharides were selected as NADES H‐bond donors and investigated with a phenothiazine‐based sensitizer carrying a glucose functionality and a glucose‐based co‐adsorbent (glucuronic acid) to explore directional intermolecular interactions and to improve the PV performance. The highest power conversion efficiencies were recorded for cells containing the glucose‐based sensitizer in the presence of glucuronic acid in the sugar‐based NADES. When one of these components was omitted, performances were lower, suggesting that the best response came from an interplay between the sugar‐based units. Not only has the unprecedented use of a NADES as a fully natural and bio‐renewable dye‐sensitized solar cell medium been presented, but for the first time an active role of the electrolyte solvent has been reported and exploited to increase the performance of the solar device.
Interface Engineering of MoS2‐Modified Graphitic Carbon Nitride Nano‐photocatalysts for an Efficient Hydrogen Evolution Reaction
Authors: Koutsouroubi Eirini D. , Vamvasakis Ioannis , Papadas Ioannis T. , Drivas Charalampos , Choulis Stelios A. , Kennou Stella , Armatas Gerasimos S. 
Published: March 2020

AbstractUnderstanding of photochemical charge transfer processes at nanoscale heterojunctions is essential in developing effective catalysts. Here, we utilize a controllable synthesis method and a combination of optical absorption, photoluminescence, and electrochemical impedance spectroscopic studies to investigate the effect of MoS2 nanosheet lateral dimension and edge length size on the photochemical behavior of MoS2‐modified graphitic carbon nitride (g‐C3N4) heterojunctions. These nano‐heterostructures, which comprise interlayer junctions with variable area (i. e., MoS2 lateral size ranges from 18 nm to 52 nm), provide a size‐tunable interfacial charge transfer through the MoS2/g‐C3N4 contacts, while exposing a large fraction of surface MoS2 edge sites available for the hydrogen evolution reaction. Importantly, modification of g‐C3N4 with MoS2 layers of 39±5 nm lateral size (20 wt % loading) creates interfacial contacts with relatively large number of MoS2 edge sites and efficient electronic transport phenomena, yielding a high photocatalytic H2‐production activity of 1497 μmol h−1 gcat−1 and an apparent QY of 3.3 % at 410 nm light irradiation. This study thus offers a design strategy to improve light energy conversion efficiency of catalysts by engineering interfaces at the nanoscale in 2D‐layered heterojunction materials.
Improved Chemical Stability of Organometal Halide Perovskite Solar Cells Against Moisture and Heat by Ag Doping
Authors: Park Chaneui , Yang Seok Joo , Choi Jinhyeok , Song Sungwon , Choi Wookjin , Cho Kilwon 
Published: March 2020

AbstractOrganometal halide perovskite (OHP) solar cells have been intensively studied because of their promising optoelectronic features, which has resulted in high power conversion efficiencies >23 %. Although OHP solar cells exhibit high power conversion efficiencies, their relatively poor stability is a significant obstacle to their practical use. We report that the chemical stability of OHP solar cells with respect to both moisture and heat can be improved by adding a small amount of Ag to the precursor. Ag doping increases the size of the OHP grains and reduces the size of the amorphous intergranular regions at the grain boundaries, and thereby hinders the infiltration of moisture into the OHP films and their thermal degradation. Quantum mechanical simulation reveals that Ag doping increases the energies of both the hydration reaction and heat‐induced vacancy formation in OHP crystals. This procedure also improves the power conversion efficiencies of the resulting solar cells.
Template assisted synthesis of Sn@C microspheres and SnO2@C micro bowls as anode for Li‐Ion batteries
Authors: Gurunathan Padalingam , Karthick Babu Morekonda Ganesh , Ramesha Kannadka 
Published: March 2020

AbstractThere are ongoing efforts to improve the energy density of current day Li‐ion batteries by using alloy‐based anodes such as Si, Sn, or SnO2 in place of graphite. Here we report template‐assisted synthesis of Sn@C microspheres and SnO2@C microbowls prepared by phloroglucinol (P) − formaldehyde (F) gel method. The structural and morphological characterizations are carried out using XRD, FESEM, and HR‐TEM. The electrochemical performance of SnO2@C as anode for Li‐ion battery is investigated through cyclic voltammetry (CV) and galvanostatic charge‐discharge cycling. At 1C rate, SnO2@C delivers a discharge capacity of 651 mA h g−1 over 150 cycles. Even at 5C rate, a reversible capacity of 494 mA h g−1 is observed with 72% of capacity retention over 200 cycles. Electrochemical impedance measurements also infer faster Li‐ion transport kinetics in the electrode material. The postmortem FESEM images on electrochemically cycled material show that porous hollow structure is retained even after prolonged cycling. For comparison, the Li storage property of Sn@C microspheres (MS) tested as anode for Li‐ion battery applications. This Sn@C composite delivered an excellent cycling capacity of 636 mA h g−1 at 1C rate over 400 cycles. When cycled at higher rate 5C, Sn@C composite exhibits high reversible capacity of 257 mA h g−1 with 68% of capacity retention over 250 cycles. These results highlight that combination of hollow architecture and porous carbon matrix of Sn@C and SnO2@C electrode provides better mechanical support to alleviate volume expansion issue of Sn electrode.
Privacy‐preserving data aggregation scheme for edge computing supported vehicular ad hoc networks
Authors: Zhao Ouyang , Liu Xuchong , Li Xiong , Singh Pitam , Wu Fan 
Published: March 2020

AbstractVehicular ad hoc networks (VANETs) allow vehicles getting road situation by connecting with roadside unit (RSU) through the on‐board unit, and this information can be processed to improve transportation services in a timely manner. Meanwhile, the three‐tier edge computing system can support the VANETs well. However, the limited bandwidth of the VANETs and the privacy of uploaded data are still issues to be resolved. Data aggregation is an effective way to address the issue of limited bandwidth and data privacy protection for individual devices. In this article, based on the bilinear pairing and Paillier homomorphic encryption, we design a privacy‐preserving data aggregation scheme for edge computing supported VANETs, which not only preserves the privacy of uploaded data but also realizes batch operations. Also, the proposed scheme guarantees the features of data integrity and source authentication. Moreover, the comparison of performance evaluation between ours and other recent schemes shows that the proposed scheme significantly reduces the communication overhead and is more suitable for resource‐constrained terminal device.
Multi‐scale network regression for brain‐phenotype associations
Authors: Xia Cedric Huchuan , Ma Zongming , Cui Zaixu , Bzdok Danilo , Thirion Bertrand , Bassett Danielle S. , Satterthwaite Theodore D. , Shinohara Russell T. , Witten Daniela M. 
Published: March 2020

AbstractBrain networks are increasingly characterized at different scales, including summary statistics, community connectivity, and individual edges. While research relating brain networks to behavioral measurements has yielded many insights into brain‐phenotype relationships, common analytical approaches only consider network information at a single scale. Here, we designed, implemented, and deployed Multi‐Scale Network Regression (MSNR), a penalized multivariate approach for modeling brain networks that explicitly respects both edge‐ and community‐level information by assuming a low rank and sparse structure, both encouraging less complex and more interpretable modeling. Capitalizing on a large neuroimaging cohort (n = 1, 051), we demonstrate that MSNR recapitulates interpretable and statistically significant connectivity patterns associated with brain development, sex differences, and motion‐related artifacts. Compared to single‐scale methods, MSNR achieves a balance between prediction performance and model complexity, with improved interpretability. Together, by jointly exploiting both edge‐ and community‐level information, MSNR has the potential to yield novel insights into brain‐behavior relationships.