bluuebunny/crossref_metadata_2025_split huggingface dataset:
Image quality evaluation of intra‐irradiation cone‐beam computed tomography acquired during one‐ and two‐arc prostate volumetric‐modulated arc therapy delivery: A phantom study
Authors: Iramina Hiraku , Kitamura Ayaka , Nakamura Mitsuhiro , Mizowaki Takashi 
Published: November 2020

AbstractPurposeTo evaluate (a) the effects of megavoltage (MV)‐scatter on concurrent kilovoltage (kV) projections (PMVkV) acquired during rotational delivery, and (b) the image quality of intra‐irradiation cone‐beam computed tomography (ii‐CBCT) images acquired during prostate volumetric‐modulated arc therapy (VMAT) delivery.MethodsExperiment (1): PMVkVs were acquired with various MV beam parameters using a cylindrical phantom: field size (FS), MV energy (6 or 15 MV), dose rate (DR), and gantry speed. The average pixel values were calculated in a region on each PMVkV which were extracted at eight equally spaced gantry angles. Experiment (2): 11 one‐arc and seven two‐arc 15 MV prostate VMAT plans were used along with a pelvis phantom. One plan was selected from each of arc plans and its MV energy was changed to 6 MV. After PMVkVs were acquired, projections consisting of MV‐scatter only (PMVS) were acquired with closing kV blades and subtracted from PMVkV (PMVScorr). Projections by kV beams only were acquired (PkV). The corresponding CBCT images were reconstructed (CBCTMVkV, CBCTMVScorr, and CBCTkV). The root‐mean‐square errors (RMSEs) were calculated in prostate region and 3D gamma analysis was conducted, in which the CBCT‐number was used instead of doses between ii‐CBCT images and CBCTkV (30 HU/1 mm).ResultsExperiment (1): The MV‐scatters were dependent on the FSs, MV energies, and DRs. Experiment (2): The median RMSEs for CBCTMVScorr were decreased by 107.5 HU (1‐arc) and 42.9 HU (2‐arc) compared to those for CBCTMVkV. The median GPRs for CBCTMVScorr were 94.7% (1‐arc) and 93.4% (2‐arc), while those for CBCTMVkV were 61.1% and 79.9%, respectively. GPRs for 6 MV plans were smaller than those for 15 MV plans.ConclusionsThe number of MV‐scatters increased with larger FSs and DRs, and smaller MV energy. The MV‐scatters were corrected on the CBCTMVScorr regardless of the number of arcs.
Reproducibility of liver iron concentration estimates in MRI through R2* measurement determined by least‐squares curve fitting
Authors: Headley Andrew M. , Grice Jared V. , Pickens David R. 
Published: November 2020

AbstractMeasuring transverse relaxation rate (R2* = 1/T2*) via MRI allows for noninvasive evaluation of multiple clinical parameters, including liver iron concentration (LIC) and fat fraction. Both fat and iron contribute to diffuse liver disease when stored in excess in the liver. This liver damage leads to fibrosis and cirrhosis with an increased risk of developing hepatocellular carcinoma. Liver iron concentration is linearly related to R2* measurements using MRI. A phantom was constructed to assess R2* quantification variability on 1.5 and 3 T MRI systems. Quantification was executed using least‐squares curve fitting techniques. The phantom was created using readily available, low‐cost materials. It contains four vials with R2* values that cover a clinically relevant range (100 to 420 Hz at 1.5 T). Iron content was achieved using ferric chloride solutions contained in glass vials, each affixed in a three‐dimensional (3D)‐printed polylactide (PLA) structure, surrounded by distilled water, all housed in a sealed acrylic cylinder. Multiple phantom stands were also 3D‐printed using PLA for precise orientation of the phantom with respect to the direction of the static magnetic field. Acquisitions at different phantom angles, across multiple MRI systems, and with different pulse sequence parameters were evaluated. The variability between any two R2* measurements, taken in the same vial under these various acquisition conditions, on a 1.5 T MRI system, was <7% for each of the four vials. For 3 T MRI systems, variability was less than 14% in all cases. Variability was <6% for both 1.5 and 3 T acquisitions when unchanged pulse sequence parameters were used. The phantom can be used to mimic a range of clinically relevant levels of R2* relaxation rates, as measured using MRI. These measurements were found to be reproducible relative to the gold‐standard method, liver biopsy, across several different image acquisition conditions.
Rational Design of Metal Oxide‐Based Heterostructure for Efficient Photocatalytic and Photoelectrochemical Systems
Authors: Xia Chengkai , Wang Heng , Kim Jung Kyu , Wang Jingyu 
Published: November 2020

AbstractSolar‐driven photo‐to‐chemical conversion is an interesting approach for energy harvesting and storage with high sustainability. To achieve high photo‐to‐chemical conversion efficiency, it is important to develop cost‐effective and stable catalysts with high activity. Metal oxides provide an interesting platform for the development of efficient catalysts owing to their abundance, high stability, and tunable band edges. Their performance highly depends on the rational design of heterostructures with engineered electronic structures, modified charge migration behavior, tailored interfacial properties, and amplified electromagnetic fields. All these enable the achievement of efficient light harvesting, promoted charge separation and transport, and accelerated surface reactions. Herein, a recent study on rationally designed metal oxide heterostructures for enhancing photo‐to‐chemical energy conversion via photocatalytic and photoelectrochemical systems is reviewed. The approaches to enhance their conversion efficiency are as follows: 1) surface modification via loading of plasmonic metals and other photosensitizers; 2) surface regulation, including morphology, defect, and dopants; 3) interfacial assembly with metal oxides, other metal compounds, and metal‐free materials. Moreover, the underlying reaction mechanisms of metal oxide‐based heterostructures and how they affect the energy conversion efficiency are discussed. Finally, the challenges and perspectives on the development of metal oxide‐based heterostructures and associated photo‐to‐chemical devices are presented.
Digitally Fabricated and Naturally Augmented In Vitro Tissues
Authors: Duarte Campos Daniela F. , De Laporte Laura 
Published: November 2020

AbstractHuman in vitro tissues are extracorporeal 3D cultures of human cells embedded in biomaterials, commonly hydrogels, which recapitulate the heterogeneous, multiscale, and architectural environment of the human body. Contemporary strategies used in 3D tissue and organ engineering integrate the use of automated digital manufacturing methods, such as 3D printing, bioprinting, and biofabrication. Human tissues and organs, and their intra‐ and interphysiological interplay, are particularly intricate. For this reason, attentiveness is rising to intersect materials science, medicine, and biology with arts and informatics. This report presents advances in computational modeling of bioink polymerization and its compatibility with bioprinting, the use of digital design and fabrication in the development of fluidic culture devices, and the employment of generative algorithms for modeling the natural and biological augmentation of in vitro tissues. As a future direction, the use of serially linked in vitro tissues as human body‐mimicking systems and their application in drug pharmacokinetics and metabolism, disease modeling, and diagnostics are discussed.
Microbubbles Containing Lysolipid Enhance Ultrasound‐Mediated Blood–Brain Barrier Breakdown In Vivo
Authors: Vince Oliver , Peeters Sarah , Johanssen Vanessa A. , Gray Michael , Smart Sean , Sibson Nicola R. , Stride Eleanor 
Published: November 2020

AbstractUltrasound and microbubbles (MBs) offer a noninvasive method of temporarily enhancing blood–brain barrier (BBB) permeability to therapeutics. To reduce off‐target effects, it is desirable to minimize the ultrasound pressures required. It has been shown that a new formulation of MBs containing lysolipids (Lyso‐MBs) can increase the cellular uptake of a model drug in vitro. The aim of this study is to investigate whether Lyso‐MBs can also enhance BBB permeability in vivo. Female BALB/c mice are injected with either Lyso‐MBs or control MBs and gadolinium‐DTPA (Gd‐DTPA) and exposed to ultrasound (500 kHz, 1 Hz pulse repetition frequency, 1 ms pulse length, peak‐negative pressures 160–480 kPa) for 2 min. BBB permeabilization is measured via magnetic resonance imaging (7.0 T) of Gd‐DTPA extravasation and subsequent histological examination of brain tissue to assess serum immunoglobulin G (IgG) extravasation (n = 8 per group). An approximately twofold enhancement in BBB permeability is produced by the Lyso‐MBs at the highest ultrasound pressure compared with the control. These findings indicate that modifying the composition of phospholipid‐shelled MBs has the potential to improve the efficiency of BBB opening, without increasing the ultrasound pressure amplitude required. This is particularly relevant for delivery of therapeutics deep within the brain.
Rational Design of Ni‐Based Electrocatalysts by Modulation of Iron Ions and Carbon Nanotubes for Enhanced Oxygen Evolution Reaction
Authors: Song Daqi , Wang Liang , Yao Mengyao , Sun Weiwei , Vajtai Robert , Ajayan Pulickel M. , Wang Yong 
Published: November 2020

AbstractAlthough Ni‐based compounds perform well as oxygen evolution reaction (OER) catalysts, several challenges hinder their potential applications, namely, complicated synthesis and pyrolysis, poor conductivity, and poor stability. Herein, a facile large‐scale synthesis strategy is designed for unique Fe‐doped Ni‐based metal‐organic polymer@carbon nanotubes (CNTs) composites that may be used as OER electrocatalysts without further treatment. The Ni1.95Fe‐MOP@CNTs deliver a small overpotential of 256 mV to achieve a current density of 10 mA cm−2, and their Tafel slope is low to 58 mV dec−1. In addition, the catalyst displays high durability after a long‐term test of 60 000 s. Introducing Fe ions and CNTs into Ni‐based compounds increases the surface area and enhances the degree of graphitization and the composite conductivity, contributing to the excellent catalytic performance. The charge transfer reaction dynamics are explored using in situ differential electrochemical mass spectrometry. Surprisingly, the Ni1.95Fe‐MOP@CNTs demonstrate a Faraday efficiency of (≈92.7%) for O2 production. These findings pave a new way for synthesizing catalysts without post‐processing for water oxidation.
Seamlessly Splicing Metallic SnxMo1−xS2 at MoS2 Edge for Enhanced Photoelectrocatalytic Performance in Microreactor
Authors: Shao Gonglei , Lu Yizhen , Hong Jinhua , Xue Xiong‐Xiong , Huang Jinqiang , Xu Zheyuan , Lu Xiangchao , Jin Yuanyuan , Liu Xiao , Li Huimin , Hu Sheng , Suenaga Kazu , Han Zheng , Jiang Ying , Li Shisheng , Feng Yexin , Pan Anlian , Lin Yung‐Chang , Cao Yang , Liu Song 
Published: November 2020

AbstractAccurate design of the 2D metal–semiconductor (M–S) heterostructure via the covalent combination of appropriate metallic and semiconducting materials is urgently needed for fabricating high‐performance nanodevices and enhancing catalytic performance. Hence, the lateral epitaxial growth of M–S SnxMo1−xS2/MoS2 heterostructure is precisely prepared with in situ growth of metallic SnxMo1−xS2 by doping Sn atoms at semiconductor MoS2 edge via one‐step chemical vapor deposition. The atomically sharp interface of this heterostructure exhibits clearly distinguished performance based on a series of characterizations. The oxygen evolution photoelectrocatalytic performance of the epitaxial M–S heterostructure is 2.5 times higher than that of pure MoS2 in microreactor, attributed to the efficient electron–hole separation and rapid charge transfer. This growth method provides a general strategy for fabricating seamless M–S lateral heterostructures by controllable doping heteroatoms. The M–S heterostructures show increased carrier migration rate and eliminated Fermi level pinning effect, contributing to their potential in devices and catalytic system.
London Dispersion Interactions Rather than Steric Hindrance Determine the Enantioselectivity of the Corey–Bakshi–Shibata Reduction
Authors: Eschmann Christian , Song Lijuan , Schreiner Peter R. 
Published: November 2020

AbstractThe well‐known Corey–Bakshi–Shibata (CBS) reduction is a powerful method for the asymmetric synthesis of alcohols from prochiral ketones, often featuring high yields and excellent selectivities. While steric repulsion has been regarded as the key director of the observed high enantioselectivity for many years, we show that London dispersion (LD) interactions are at least as important for enantiodiscrimination. We exemplify this through a combination of detailed computational and experimental studies for a series of modified CBS catalysts equipped with dispersion energy donors (DEDs) in the catalysts and the substrates. Our results demonstrate that attractive LD interactions between the catalyst and the substrate, rather than steric repulsion, determine the selectivity. As a key outcome of our study, we were able to improve the catalyst design for some challenging CBS reductions.
Functional expression of eukaryotic cytochrome P450s in yeast
Authors: Jiang Lihong , Huang Lei , Cai Jin , Xu Zhinan , Lian Jiazhang 
Published: November 2020

AbstractCytochrome P450 enzymes (P450s) are a superfamily of heme‐thiolate proteins widely existing in various organisms. Due to their key roles in secondary metabolism, degradation of xenobiotics, and carcinogenesis, there is a great demand to heterologously express and obtain a sufficient amount of active eukaryotic P450s. However, most eukaryotic P450s are endoplasmic reticulum‐localized membrane proteins, which is the biggest challenge for functional expression to high levels. Furthermore, the functions of P450s require the cooperation of cytochrome P450 reductases for electron transfer. Great efforts have been devoted to the heterologous expression of eukaryotic P450s, and yeasts, particularly Saccharomyces cerevisiae are frequently considered as the first expression systems to be tested for this challenging purpose. This review discusses the strategies for improving the expression and activity of eukaryotic P450s in yeasts, followed by examples of P450s involved in biosynthetic pathway engineering.
Ten‐year‐old boy with atypical COVID‐19 symptom presentation: A case report
Authors: Houshmand Hamidreza , Abounoori Mahdi , Ghaemi Reza , Bayat Sara , Houshmand Gholamreza 
Published: November 2020

AbstractSince reactive arthritis (ReA) and urticaria could be seen in this age group along with atypical COVID‐19 symptom presentation, pediatrics should be familiar with urticarial rashes and ReA in COVID‐19 to enable early diagnoses of infected individuals.
Interfacial Engineering in a Cathode Composite Based on Garnet‐Type Solid‐State Li‐Ion Battery with High Voltage Cycling
Authors: Balasubramaniam Ramkumar , Nam Chan‐Woo , Aravindan Vanchiappan , Eum Donggun , Kang Kisuk , Lee Yun‐Sung 
Published: November 2020

AbstractGarnet‐type solid electrolyte is a promising candidate for the fabrication of high energy all‐solid‐state Li‐ion batteries (ASSLIBs), but its use is hampered by a large interfacial resistance. Herein, we propose a surface modification and subsequent sintering to enhance the interfacial connection between the cathode and the solid electrolyte. The ASSLIB prepared by this method delivered an initial discharge capacity of ∼66 mAh g−1 (80 °C) at a rate of 0.1 C. However, the poor contact between the cathode and electrolyte triggered the increase of the interfacial resistance, which caused severe capacity decay upon cycling. The encapsulation of LiCoO2 particles with LiBO2 using a single‐step sintering process dramatically increased the interfacial contact, resulting in a higher discharge capacity of 116 mAh g−1 with good cycling behavior. Therefore, surface modification of the cathode offers a reduction of resistance and promotes efficient Li‐ion transfer pathways across the cathode/solid‐electrolyte interface.
Carbon Nanodots in Electrochemical Sensors and Biosensors: A Review
Authors: Hassanvand Zahra , Jalali Fahimeh , Nazari Maryam , Parnianchi Fatemeh , Santoro Carlo 
Published: November 2020

AbstractThis Review presents the latest advances in designing electrochemical sensors by using carbon nanodots (CNDs), carbon dots (CDs), and graphene quantum dots (GQDs), as a new class of photoluminescent nanomaterials, which can be employed in a vast number applications, such as biomedicine, biosensing, optical sensing, catalysis, solar cells, imaging, and electrochemical sensing. Recently, the application of CDs and GQDs in electrochemical sensing has increased significantly because of their unique features such as quantum size, excellent biocompatibility, enzyme‐like activity, high active area, and abundance of hydrophilic groups, such as hydroxyl, carboxyl, or amine functionalities. The applications of CDs and GQDs for the electrochemical sensing of hydrogen peroxide, glucose, other organic molecules, as well as metal ions are presented. The utilization of CDs and GQDs for immunosensing and aptasensing is also reported.
Facile Synthesis of Size‐Controlled Nitrogen‐Doped Mesoporous Carbon Nanosphere Supported Ultrafine Ru Nanoparticles for Selective Hydrogenation of Quinolines
Authors: Tian Zhengbin , Jiang Haibin , Huang Minghua , Wang Guang‐Hui 
Published: November 2020

AbstractNitrogen‐doped mesoporous carbon nanosphere (NMCS) with tunable sizes and uniform mesoporosity was synthesized by a facile soft‐templating method. During the synthesis, F127 (PEO–PPO–PEO triblock copolymer) could be used not only as a soft template to generate the mesostructure but also as a size‐control agent to tailor the size of NMCS in a relatively wide range of 100 to 700 nm. In addition, the synthesis process was simple and suitable for large‐scale production. Moreover, the NMCS was used as support of ultrafine Ru nanoparticles (Ru/NMCS), which exhibited good catalytic performances for selective hydrogenation of quinolones. It is expected that the simple synthetic strategy for the NMCS can generate extensive interest in many catalysis and sorption applications.
Aromatic Aza‐Claisen Rearrangement of Arylpropargylammonium Salts Generated in situ from Arynes and Tertiary Propargylamines
Authors: Han Lu , Li Sheng‐Jun , Zhang Xue‐Ting , Tian Shi‐Kai 
Published: November 2020

AbstractThe charge‐accelerated aza‐Claisen rearrangement of ammonium salts serves as a key step in the construction of complex nitrogen‐containing molecules. However, much less attention has been paid to the aromatic aza‐Claisen rearrangement than to the aliphatic one. Herein, we report an unprecedented aromatic aza‐Claisen rearrangement of arylpropargylammonium salts, generated in situ from arynes and tertiary propargylamines, delivering structurally diverse 2‐propargylanilines in moderate to good yields with high regioselectivity. This rearrangement proceeds in the absence of strong bases or transition metals, is compatible with moisture and air, tolerates a wide variety of functional groups, and is amenable to forming 11‐ to 13‐membered heterocycles with a triple bond. The 2‐propargylaniline products were treated with aluminum chloride in ethanol to afford multisubstituted indoles in moderate to excellent yields. Finally, a series of deuterium‐labeling experiments was performed to elucidate the reaction mechanism.
The Aggregation Pattern of Aβ1–40 is Altered by the Presence of N‐Truncated Aβ4–40 and/or CuII in a Similar Way through Ionic Interactions
Authors: Stefaniak Ewelina , Atrian‐Blasco Elena , Goch Wojciech , Sabater Laurent , Hureau Christelle , Bal Wojciech 
Published: November 2020

AbstractAlzheimer's disease (AD) is one of the most common of the multifactorial diseases and is characterized by a range of abnormal molecular processes, such as the accumulation of extracellular plaques containing the amyloid‐β (Aβ) peptides and dyshomeostasis of copper in the brain. In this study, we have investigated the effect of CuII on the aggregation of Aβ1–40 and Aβ4–40, representing the two most prevalent families of Aβ peptides, that is, the full length and N‐truncated peptides. Both families are similarly abundant in healthy and AD brains. For either of the studied peptides, substoichiometric CuII concentrations accelerated aggregation, whereas superstoichiometric CuII inhibited fibril formation, likely by stabilizing the oligomers. The addition of either Aβ4–40 or substoichiometric CuII affected the aggregation profile of Aβ1–40, by yielding shorter and thicker fibrils; amorphous aggregates were formed in the presence of a molar excess of CuII. The similarity of these two effects can be attributed to the increase in the positive charge on the Aβ N terminus, caused both by CuII complexation and N truncation at position 4. Our findings provide a better understanding of the biological Aβ aggregation process as these two Aβ species and CuII coexist and interact under physiological conditions.
Construction of Helical Structures with Multiple Fused Anthracenes: Structures and Properties of Long Expanded Helicenes
Authors: Fujise Kei , Tsurumaki Eiji , Wakamatsu Kan , Toyota Shinji 
Published: November 2020

AbstractPolycyclic aromatic compounds consisting of four or five fused anthracene units were synthesized by PtCl2‐catalyzed cycloisomerization as novel long expanded helicenes. These compounds have helical structures with significant stacking of the terminal anthracene moieties at 0.33 nm interlayer distance. In the UV‐vis and fluorescence spectra, the absorption and emission bands were red‐shifted as the number of fused anthracene units was increased. The characteristic broad and long‐lived emission bands of the long analogues are explained by the excimer‐like stabilization of the excited state. These photophysical data as well as their cyclic voltammetric data are discussed on the basis of the π‐conjugation and interlayer π⋅⋅⋅π interactions in the molecular structures and the molecular orbitals. The barrier and mechanism of helical inversion are also reported.
Enantioseparation of ketoconazole and miconazole by capillary electrophoresis and a study on their inclusion interactions with β‐cyclodextrin and derivatives
Authors: Azhari Nurul Raihana , Yahaya Noorfatimah , Mohd Suah Faiz Bukhari M. , Prabu Samikannu , Yih Hui Boon , Shahriman Mohamad Shariff , Mohamad Zain Nur Nadhirah , Raoov Muggundha 
Published: November 2020

AbstractA chiral separation method coupled with capillary electrophoresis (CE) analysis for ketoconazole and miconazole enantiomers using chiral selectors such as β‐cyclodextrin (β‐CD) and hydroxypropyl‐β‐CD (HP‐β‐CD) was developed in this study, which included the optimisation, validation and application of the method on the antifungal cream samples. The formation of inclusion complex between the hosts (β‐CD and HP‐β‐CD) and guests (ketoconazole and miconazole) were compared and analysed using ultraviolet–visible spectrophotometry, nuclear magnetic resonance (NMR) spectroscopy and molecular docking methods. Results from the study showed that in a concentration that ranged between 0.25 and 50 mg L−1, the linear calibration curves of each enantiomer had a high coefficient of regression (R2 > 0.999), low limit of detection (0.075 mg L−1) and low limit of quantification (0.25 mg L−1). The relative standard deviation (RSD) of the intraday and interday analyses ranged from 0.79% to 8.01% and 3.30% to 11.43%, respectively, while the recoveries ranged from 82.0% to 105.7% (RSD < 7%, n = 3). The most probable structure of the inclusion complexes was proposed based on the findings from the molecular docking studies conducted using the PatchDock server.