bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tolerance levels of mass density for CT number calibration in photon radiation therapy
Authors: Nakao Minoru , Ozawa Shuichi , Yogo Katsunori , Miura Hideharu , Yamada Kiyoshi , Hosono Fumika , Hayata Masahiro , Miki Kentaro , Nakashima Takeo , Ochi Yusuke , Kawahara Daisuke , Morimoto Yoshiharu , Yoshizaki Toru , Nozaki Hiroshige , Habara Kosaku , Nagata Yasushi 
Published: May 2019

AbstractComputed tomography (CT) data are required to calculate the dose distribution in a patient’s body. Generally, there are two CT number calibration methods for commercial radiotherapy treatment planning system (RTPS), namely CT number‐relative electron density calibration (CT‐RED calibration) and CT number‐mass density calibration (CT‐MD calibration). In a previous study, the tolerance levels of CT‐RED calibration were established for each tissue type. The tolerance levels were established when the relative dose error to local dose reached 2%. However, the tolerance levels of CT‐MD calibration are not established yet. We established the tolerance levels of CT‐MD calibration based on the tolerance levels of CT‐RED calibration. In order to convert mass density (MD) to relative electron density (RED), the conversion factors were determined with adult reference computational phantom data available in the International Commission on Radiological Protection publication 110 (ICRP‐110). In order to validate the practicability of the conversion factor, the relative dose error and the dose linearity were validated with multiple RTPSes and dose calculation algorithms for two groups, namely, CT‐RED calibration and CT‐MD calibration. The tolerance levels of CT‐MD calibration were determined from the tolerance levels of CT‐RED calibration with conversion factors. The converted RED from MD was compared with actual RED calculated from ICRP‐110. The conversion error was within ±0.01 for most standard organs. It was assumed that the conversion error was sufficiently small. The relative dose error difference for two groups was less than 0.3% for each tissue type. Therefore, the tolerance levels for CT‐MD calibration were determined from the tolerance levels of CT‐RED calibration with the conversion factors. The MD tolerance levels for lung, adipose/muscle, and cartilage/spongy‐bone corresponded to ±0.044, ±0.022, and ±0.045 g/cm3, respectively. The tolerance levels were useful in terms of approving the CT‐MD calibration table for clinical use.
Microfluidic Fabrication of Biomimetic Helical Hydrogel Microfibers for Blood‐Vessel‐on‐a‐Chip Applications
Authors: Jia Luanluan , Han Fengxuan , Yang Huili , Turnbull Gareth , Wang Jiayuan , Clarke Jon , Shu Wenmiao , Guo Mingyu , Li Bin 
Published: May 2019

AbstractNature has created many perfect helical microstructures, including DNA, collagen fibrils, and helical blood vessels, to achieve unique physiological functions. While previous studies have developed a number of microfabrication strategies, the preparation of complex helical structures and cell‐laden helical structures for biomimetic applications remains challenging. In this study, a one‐step microfluidics‐based methodology is presented for preparing complex helical hydrogel microfibers and cell‐laden helical hydrogel microfibers. Several types of complex helical structures, including multilayer helical microfibers and superhelical hollow microfibers with helical channels, are prepared by simply tuning the flow rates or modifying the geometry of microfluidic device. With the decent perfusability, the hollow microfibers may simulate the structural characteristics of helical blood vessels and create swirling blood flow in a blood‐vessel‐on‐chip setup. Such hydrogel‐based helical microstructures may potentially be used in areas such as blood vessel tissue engineering, organ‐on‐chips, drug screening, and biological actuators.
Defect‐Tailoring Mediated Electron–Hole Separation in Single‐Unit‐Cell Bi3O4Br Nanosheets for Boosting Photocatalytic Hydrogen Evolution and Nitrogen Fixation
Authors: Di Jun , Xia Jiexiang , Chisholm Matthew F. , Zhong Jun , Chen Chao , Cao Xingzhong , Dong Fan , Chi Zhen , Chen Hailong , Weng Yu‐Xiang , Xiong Jun , Yang Shi‐Ze , Li Huaming , Liu Zheng , Dai Sheng 
Published: May 2019

AbstractSolar photocatalysis is a potential solution to satisfying energy demand and its resulting environmental impact. However, the low electron–hole separation efficiency in semiconductors has slowed the development of this technology. The effect of defects on electron–hole separation is not always clear. A model atomically thin structure of single‐unit‐cell Bi3O4Br nanosheets with surface defects is proposed to boost photocatalytic efficiency by simultaneously promoting bulk‐ and surface‐charge separation. Defect‐rich single‐unit‐cell Bi3O4Br displays 4.9 and 30.9 times enhanced photocatalytic hydrogen evolution and nitrogen fixation activity, respectively, than bulk Bi3O4Br. After the preparation of single‐unit‐cell structure, the bismuth defects are controlled to tune the oxygen defects. Benefiting from the unique single‐unit‐cell architecture and defects, the local atomic arrangement and electronic structure are tuned so as to greatly increase the charge separation efficiency and subsequently boost photocatalytic activity. This strategy provides an accessible pathway for next‐generation photocatalysts.
Giant Enhancement in the Supercapacitance of NiFe–Graphene Nanocomposites Induced by a Magnetic Field
Authors: Romero Jorge , Prima‐Garcia Helena , Varela Maria , Miralles Sara G. , Oestreicher Víctor , Abellán Gonzalo , Coronado Eugenio 
Published: May 2019

AbstractThe rapid rise in energy demand in the past years has prompted a search for low‐cost alternatives for energy storage, supercapacitors being one of the most important devices. It is shown that a dramatic enhancement (≈1100%, from 155 to 1850 F g−1) of the specific capacitance of a hybrid stimuli‐responsive FeNi3–graphene electrode material can be achieved when the charge/discharge cycling is performed in the presence of an applied magnetic field of 4000 G. This result is related to an unprecedented magnetic‐field‐induced metal segregation of the FeNi3 nanoparticles during the cycling, which results in the appearance of small Ni clusters (<5 nm) and, consequently, in an increase in pseudocapacitive sites. The results open the door to a systematic improvement of the capacitance values of hybrid supercapacitors, while moving the research in this area towards the development of magnetically addressable energy‐storage devices.
Current Status and Future Prospects of Metal–Sulfur Batteries
Authors: Chung Sheng‐Heng , Manthiram Arumugam 
Published: May 2019

AbstractLithium–sulfur batteries are a major focus of academic and industrial energy‐storage research due to their high theoretical energy density and the use of low‐cost materials. The high energy density results from the conversion mechanism that lithium–sulfur cells utilize. The sulfur cathode, being naturally abundant and environmentally friendly, makes lithium–sulfur batteries a potential next‐generation energy‐storage technology. The current state of the research indicates that lithium–sulfur cells are now at the point of transitioning from laboratory‐scale devices to a more practical energy‐storage application. Based on similar electrochemical conversion reactions, the low‐cost sulfur cathode can be coupled with a wide range of metallic anodes, such as sodium, potassium, magnesium, calcium, and aluminum. These new “metal–sulfur” systems exhibit great potential in either lowering the production cost or producing high energy density. Inspired by the rapid development of lithium–sulfur batteries and the prospect of metal–sulfur cells, here, over 450 research articles are summarized to analyze the research progress and explore the electrochemical characteristics, cell‐assembly parameters, cell‐testing conditions, and materials design. In addition to highlighting the current research progress, the possible future areas of research which are needed to bring conversion‐type lithium–sulfur and other metal–sulfur batteries into the market are also discussed.
Functionalization of 2D Materials with Photosensitive Molecules: From Light‐Responsive Hybrid Systems to Multifunctional Devices
Authors: Zhao Yuda , Ippolito Stefano , Samorì Paolo 
Published: May 2019

Abstract2D materials possess exceptional physical and chemical properties that render them appealing components for numerous potential applications in (opto)electronics, energy storage, sensing, and biomedicine. However, such unique properties are hardly tunable or modifiable. The functionalization of 2D crystals with molecules constitutes a powerful strategy to adjust and modulate their properties, by also imparting them new functions. In this framework, the combination of 2D materials with photosensitive molecules is a viable route for harnessing their light‐responsive nature. The latter takes full advantage of the extremely high sensitivity of 2D materials to subtle changes in the local environment and the capacity of photosensitive molecules to modify their intrinsic properties when exposed to electromagnetic fields. The hybrid molecule–2D materials can preserve the unique optical and electrical properties of 2D layers and can exhibit additional light‐tunable features. In this Progress Report, the protocols that can be pursued for the 2D material functionalization and switching mechanisms in photosensitive systems are reviewed, followed by an in‐depth discussion on their tunable optical properties and their exploitation when integrated in novel photoswitchable electronic devices. The opportunities and associated challenges to be tackled for the development of unprecedented and high‐performance light‐responsive devices are discussed.
Giant Nonlinear Optical Response in 2D Perovskite Heterostructures
Authors: Wang Jun , Mi Yang , Gao Xian , Li Junzi , Li Junze , Lan Shangui , Fang Chen , Shen Hongzhi , Wen Xinglin , Chen Rui , Liu Xinfeng , He Tingchao , Li Dehui 
Published: May 2019

Abstract2D layered halide perovskites have attracted significant attention. Apart from the linear optical properties, it is also intriguing to explore the nonlinear optics of 2D layered halide perovskites and their heterostructures. Previous nonlinear optical (NLO) studies of 2D perovskites primarily focus on the thin films or microplates. Herein, the NLO properties of (n‐C4H9NH3)2PbI4/(n‐C4H9NH3)2(CH3NH3)Pb2I7 heterostructures with centimeter size are systematically studied. The NLO properties can be continuously tuned by changing the thickness. A giant two‐photon absorption (2PA) coefficient up to 44 cm MW−1 is obtained for the heterostructures with a total thickness of 20 µm based on the nonlinear transmittance measurement. Additionally, strong multiphoton‐induced photoluminescence is observed in the heterostructures. It is proposed that the giant 2PA coefficient might arise from the small thickness (≈1 µm) of (n‐C4H9NH3)2(CH3NH3)Pb2I7 layer and possibly the nonradiative energy transfer between the different constituting layers within the heterostructures through an antenna‐like effect. Finally, benefiting from the giant 2PA coefficient, direct detection of 980 nm light is demonstrated with a responsivity of 10−7 A W−1 in the heterostructures. The findings suggest the promising applications of 2D perovskite heterostructures in the infrared photodetection and some other nonlinear absorption related optoelectronic devices.
Electrochemical Techniques in Battery Research: A Tutorial for Nonelectrochemists
Authors: Yang Xuming , Rogach Andrey L. 
Published: May 2019

AbstractMany researchers who are now active in the flourishing field of battery research are coming from backgrounds other than electrochemistry, and might not be in possession of a systematic electrochemical training before they start the journey of “building better batteries.” With this specific audience in mind, the authors review electrochemical techniques commonly used in battery research. Starting from an introduction of the basic electrochemistry concepts, the authors offer a detailed discussion of potential, galvanic, and impedance measurement techniques, providing practical details and useful comments on performing both the data acquisition and analysis. One aim of this essay is to emphasize the importance of standard evaluation of the battery performance.
Atomic Layer Deposition as a General Method Turns any 3D‐Printed Electrode into a Desired Catalyst: Case Study in Photoelectrochemisty
Authors: Browne Michelle P. , Plutnar Jan , Pourrahimi Amir Masoud , Sofer Zdenek , Pumera Martin 
Published: May 2019

Abstract3D‐printing technologies have begun to revolutionize many manufacturing processes, however, there are still significant limitations that are yet to be overcome. In particular, the material from which the products are fabricated is limited by the 3D‐printing material precursor. Particularly, for photoelectrochemical (PEC) energy applications, the as‐printed electrodes can be used as is, or modified by postfabrication processes, e.g., electrochemical deposition or anodization, to create active layers on the 3D‐printed electrodes. However, the as‐printed electrodes are relatively inert for various PEC energy applications, and the aforementioned postfabrication processing techniques do not offer layer conformity or control at the Ångström/nano level. Herein, for the first time, atomic layer deposition (ALD) is utilized in conjunction with metal 3D‐printing to create active electrodes. To illustrate the proof‐of‐concept, TiO2 is deposited by ALD onto stainless steel 3D‐printed electrodes and subsequently investigated as a photoanode for PEC water oxidation. Furthermore, by tuning the TiO2 thickness by ALD, the activity can be optimized. By combining 3D‐printing and ALD, instead of other metal deposition techniques, i.e., sputtering, rapid prototyping of electrodes with controllable thickness of the desired material onto an as‐printed electrodes with any porosity can be achieved that can benefit a multitude of energy applications.
Asymmetric Nonfullerene Small Molecule Acceptors for Organic Solar Cells
Authors: Li Chao , Fu Huiting , Xia Tian , Sun Yanming 
Published: May 2019

AbstractSymmetry breaking provides a new material design strategy for nonfullerene small molecule acceptors (SMAs). The past 10 years have witnessed significant advances in asymmetric nonfullerene SMAs in organic solar cells (OSCs) with power conversion efficiency (PCE) increasing from ≈1% to ≈14%. In this review, the progress of asymmetric nonfullerene SMAs, including early reports of asymmetric nonfullerene SMAs, asymmetric PDI‐based nonfullerene SMAs, and asymmetric acceptor–donor–acceptor (A–D–A)‐type nonfullerene SMAs, is summarized. The structure–property relationships and the perspectives for future development of asymmetric nonfullerene SMAs are also discussed.
A functional decomposition of sex inconstancy in the dioecious, colonizing plant Mercurialis annua
Authors: Cossard Guillaume G. , Pannell John R. 
Published: May 2019

PremisePlants with separate sexes often show “inconstant” or “leaky” sex expression, with females or males producing a few flowers of the opposite sex. The frequency and degree of such inconstancy may reflect residual hermaphroditic sex allocation after an evolutionary transition from combined to separate sexes. Sex inconstancy also represents a possible first step in the breakdown of dioecy back to hermaphroditism. In the Mercurialis annua (Euphorbiaceae) species complex, monoecy and androdioecy have evolved from dioecy in polyploid populations. Here, we characterize patterns of sex inconstancy in dioecious M. annua and discuss how sex inconstancy may have contributed to the breakdown of separate sexes in the genus.MethodsWe measured sex inconstancy in three common gardens of M. annua over 2 years using a modification of Lloyd's phenotypic gender in terms of frequency and degree, with the degree calibrating inconstancy against the sex allocation of constant males and constant females, yielding a measure of gender that does not depend on the distribution of gender in the population.ResultsUnusually for dioecious plants, the frequency of sex inconstancy in M. annua was greater in females, but its degree was greater for males in the 2 years of study. We suggest that this pattern is consistent with the maintenance of inconstancy in dioecious M. annua by selection for reproductive assurance under mate limitation.ConclusionsOur study illustrates the utility of decomposing measures of sex inconstancy into its frequency and its degree and throws new light on the origin of variation in sexual systems in Mercurialis.
Controlled Assembly of Block Copolymer Coated Nanoparticles in 2D Arrays
Authors: Leffler Vanessa B. , Mayr Lina , Paciok Paul , Du Hongchu , Dunin‐Borkowski Rafal E. , Dulle Martin , Förster Stephan 
Published: May 2019

AbstractThe defined assembly of nanoparticles (NPs) in polymer matrices is an important prerequisite for next‐generation functional materials. A promising approach to control NP positions in polymer matrices at the nanometer scale is the use of block copolymers. It allows the selective deposition of NPs in nanodomains, but the final defined and ordered positioning of the NPs within the domains has not been possible. This can now be achieved by coating NPs with block copolymers. The self‐assembly of block copolymer‐coated NPs directly leads to ordered microdomains containing ordered NP arrays with exactly one NP per unit cell. By variation of the grafting density, the inter‐nanoparticle distance can be controlled from direct NP surface contact to surface separations of several nanometers, determined by the thickness of the polymer shell. The method can be applied to a wide variety of block copolymers and NPs and is thus suitable for a broad range of applications.
M−O Bonding Beyond the Oxo Wall: Spectroscopy and Reactivity of Cobalt(III)‐Oxyl and Cobalt(III)‐Oxo Complexes
Authors: Andris Erik , Navrátil Rafael , Jašík Juraj , Srnec Martin , Rodríguez Mònica , Costas Miquel , Roithová Jana 
Published: May 2019

AbstractTerminal oxo complexes of late transition metals are frequently proposed reactive intermediates. However, they are scarcely known beyond Group 8. Using mass spectrometry, we prepared and characterized two such complexes: [(N4Py)CoIII(O)]+ (1) and [(N4Py)CoIV(O)]2+ (2). Infrared photodissociation spectroscopy revealed that the Co−O bond in 1 is rather strong, in accordance with its lack of chemical reactivity. On the contrary, 2 has a very weak Co−O bond characterized by a stretching frequency of ≤659 cm−1. Accordingly, 2 can abstract hydrogen atoms from non‐activated secondary alkanes. Previously, this reactivity has only been observed in the gas phase for small, coordinatively unsaturated metal complexes. Multireference ab‐initio calculations suggest that 2, formally a cobalt(IV)‐oxo complex, is best described as cobalt(III)‐oxyl. Our results provide important data on changes to metal‐oxo bonding behind the oxo wall and show that cobalt‐oxo complexes are promising targets for developing highly active C−H oxidation catalysts.
Orbitals and the Interpretation of Photoelectron Spectroscopy and (e,2e) Ionization Experiments
Authors: Truhlar Donald G. , Hiberty Philippe C. , Shaik Sason , Gordon Mark S. , Danovich David 
Published: May 2019

AbstractElectron momentum spectroscopy, scanning tunneling microscopy, and photoelectron spectroscopy provide unique information about electronic structure, but their interpretation has been controversial. This essay discusses a framework for interpretation. Although this interpretation is not new, we believe it is important to present this framework in light of recent publications. The key point is that these experiments provide information about how the electron distribution changes upon ionization, not how electrons behave in the pre‐ionized state. Therefore, these experiments do not lead to a “selection of the correct orbitals” in chemistry and do not overturn the well‐known conclusion that both delocalized molecular orbitals and localized molecular orbitals are useful for interpreting chemical structure and dynamics. The two types of orbitals can produce identical total molecular electron densities and therefore molecular properties. Different types of orbitals are useful for different purposes.
Molecularly imprinted polymer microspheres prepared via the two‐step swelling polymerization for the separation of lincomycin
Authors: Zhang Youhong , Lu Yinan , Zhong Jiliang , Li Weipeng , Wei Qing , Wang Kean 
Published: May 2019

ABSTRACTA molecularly imprinted polymer (MIP) was synthesized via a two‐step swelling polymerization method for the purification of lincomycin. Polystyrene microspheres were prepared by the dispersion‐polymerization process and used as the substrate. Methacrylic acid was used as the functional monomer, whereas ethylene glycol dimethacrylate was the cross‐linker. The MIP was structurally characterized and examined for its separation performance at different conditions (temperature, solvents, etc.). It was found that the MIP possesses the good sphericity, porosity, monodispersity, and a high adsorption capacity of (180 μmol/g) in chloroform solution. Comparison studies showed that the MIP presents a higher capacity than the NIP (non‐imprinted polymer) in chloroform solution and a much higher capacity in the practical lincomycin fermentation solution extracts, confirming the underlining mechanisms of the MIP. Scatchard plot revealed two adsorption mechanisms on the MIP, whereas the isotherm is better described by Freundlich equation. The adsorption/elution kinetics demonstrated that the MIP possesses good elution/regeneration capabilities with the elution ratio > 93%. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47938.
Unique glucose oxidation catalysis of Gluconobacter oxydans constitutes an efficient cellulosic gluconic acid fermentation free of inhibitory compounds disturbance
Authors: Zhou Pingping , Yao Ruimiao , Zhang Hongsen , Bao Jie 
Published: May 2019

AbstractToxic inhibitory compounds from lignocellulose pretreatment are the major obstacle to achieve high bioconversion efficiency in biorefinery fermentations. This study shows a unique glucose oxidation catalysis of Gluconobacter oxydans with its gluconic acid productivity free of inhibitor disturbance. The microbial experimentations and the transcriptome analysis revealed that both the activity of the membrane‐bound glucose dehydrogenase and the transcription level of the genes in periplasmic glucose oxidation respiratory chain of G. oxydans were essentially not affected in the presence of inhibitory compounds. G. oxydans also rapidly converted furan and phenolic aldehyde inhibitors into the less toxic alcohols or acids. The synergy of the robust periplasmic glucose oxidation and the rapid inhibitor conversion of G. oxydans significantly elevated the efficiency of the oxidative fermentation in lignocellulose hydrolysate. The corresponding genes responsible for the conversion of furan and phenolic aldehyde inhibitors were also mined by DNA microarrays. The synergistic mechanism of G. oxydans provided an important option of metabolic modification for enhancing inhibitor tolerance of general fermentation strains.