bluuebunny/crossref_metadata_2025_split huggingface dataset:
Atomic Layer Deposition Assisted Encapsulation of Quantum Dot Luminescent Microspheres toward Display Applications
Authors: Fang Fan , Liu Mengjia , Chen Wei , Yang Hongcheng , Liu Yizun , Li Xiang , Hao Junjie , Xu Bing , Wu Dan , Cao Kun , Lei Wei , Müller‐Buschbaum Peter , Sun Xiao Wei , Chen Rong , Wang Kai 
Published: April 2020

AbstractQuantum dots (QDs) are promising for being used in advanced displays due to their outstanding emission properties. Herein, a novel encapsulation method for QDs is reported and ultra‐stable QDs@SiO2@Al2O3 luminescent microspheres (QLuMiS) are obtained by combining a sol–gel method for the intermediate SiO2 layer with a fluidized powder atomic layer deposition (ALD) for the outer Al2O3 layer. The rich hydroxyl coverage on the QDs@SiO2 surface provides abundant chemisorption sites, which are beneficial for the deposition of Al2O3 in the ALD process. Simultaneously, the water‐oxygen channels in the SiO2 layer are blocked by the Al2O3 layer, which protects the QDs against deterioration. Consequently, the QLuMiS exhibit an excellent stability with 86% of the initial light conversion efficiency after 1000 h of blue light aging under a light power density of 2000 mW cm−2. Such stability is significantly better than that of QDs@Al2O3 and QDs@SiO2 samples. Moreover, under this strong irradiation aging condition with blue light, the extrapolated lifetime (L50) of QLuMiS is 4969 h, which is ten times longer than that of QDs@SiO2 and is the best record as far as is known. Finally, a prototype of a QLuMiS‐based cellphone screen with a wide color gamut of 115% NTSC is demonstrated.
Growth trajectories of wheat–maize intercropping with straw and plastic management in arid conditions
Authors: Yin Wen , Yu Aizhong , Guo Yao , Fan Hong , Hu Falong , Fan Zhilong , Zhao Cai , Chai Qiang , Coulter Jeffrey A. 
Published: April 2020

AbstractInterspecific interactions in intercropping can affect the yield of component crops, but little attention has been given to the dynamics of interspecific competition based on biomass accumulation in various management practices. A field experiment with wheat (Triticum aestivumL.)–maize (Zea maysL.) intercropping was conducted to evaluate the interspecific competition with four types of straw management for wheat (no‐tillage with straw standing or mulched soil and conventional tillage with straw incorporation or no straw retained) and two methods of plastic mulching for maize (no‐tillage with residual plastic mulching [i.e., new at the beginning of the previous crop, old plastic mulched in season] and conventional tillage with annual new plastic mulching). Aboveground biomass of intercrops was sampled throughout the growing season and fit to a logistic growth model. Compared with sole‐cropping, intercropping significantly increased maximum biomass and maximum growth rate of wheat but suppressed vegetative and maximum growth rates of maize. Maize growth recovered after wheat was harvested when maize was blister kernel stage (R2). Straw mulching in wheat strips and residual plastic mulching in maize strips produced greater maximum biomass amount or rates of wheat and maize than that with conventional intercropping (conventional tillage with no straw retention in wheat strips and annual new plastic mulching in maize strips). Straw mulching in wheat strips and residual plastic mulching in maize strips enhanced total grain yields by 14.9% compared with conventional intercropping. Straw mulching in wheat strips and residual plastic mulch in maize strips are suitable for coordinating interspecies interactions and increasing the productivity of wheat–maize intercropping.
The health of restaurant work: A historical and social context to the occupational health of food service
Authors: Lippert Julia , Rosing Howard , Tendick‐Matesanz Felipe 
Published: April 2020

AbstractThe United States currently has over one million restaurants, making food service one of the largest workforces and industry sectors in the nation's economy. Historically, concern for the health of early restaurant workers was tied largely to the hygiene of the food and thus the wellbeing of the customer rather than the individuals preparing the food. The landscape of occupational illness and injury that resulted is fraught with some of the starkest health disparities in wages, discrimination, benefits, injuries, and illness seen among US laborers. These disparities have consistently been associated with social class and economic position. Conditions identified during the early years of restaurant work, before the introduction of occupational safety and health protections, persist today largely due to tipped wages, dependence on customer discretion, and the management structure. Research and intervention efforts to control occupational health hazards should be directed toward the socioeconomic and structural roots of health problems among food service workers in the United States. Such efforts have important implications for enhancing worker protections, improving wages, and restructuring working conditions for restaurant and food service workers. They also suggest opportunities for occupational health practitioners and researchers to contribute to system‐level change analysis to address centuries‐old occupational health challenges still facing one of the largest sectors of workers in the country.
Cryogenic Correlative Single‐Particle Photoluminescence Spectroscopy and Electron Tomography for Investigation of Nanomaterials
Authors: Dahlberg Peter D. , Perez Davis , Su Zhaoming , Chiu Wah , Moerner W. E. 
Published: April 2020

AbstractCryogenic single‐particle photoluminescence (PL) spectroscopy has been used with great success to directly observe the heterogeneous photophysical states present in a population of luminescent particles. Cryogenic electron tomography provides complementary nanometer scale structural information to PL spectroscopy, but the two techniques have not been correlated due to technical challenges. Here, we present a method for correlating single‐particle information from these two powerful microscopy modalities. We simultaneously observe PL brightness, emission spectrum, and in‐plane excitation dipole orientation of CdSSe/ZnS quantum dots suspended in vitreous ice. Stable and fluctuating emitters were observed, as well as a surprising splitting of the PL spectrum into two bands with an average energy separation of 80 meV. In some cases, the onset of the splitting corresponded to changes in the in‐plane excitation dipole orientation. These dynamics were assigned to structures of individual quantum dots and the excitation dipoles were visualized in the context of structural features.
Progress of Organic Electrodes in Aqueous Electrolyte for Energy Storage and Conversion
Authors: Huang Jianhang , Dong Xiaoli , Guo Zhaowei , Wang Yonggang 
Published: April 2020

AbstractAqueous batteries using inorganic compounds as electrode materials are considered a promising solution for grid‐scale energy storage, while wide application is limited by the short life and/or high cost of electrodes. Organics with carbonyl groups are being investigated as the alternative to inorganic electrode materials because they offer the advantages of tunable structures, renewability, and they are environmentally benign. Furthermore, the wide internal space of such organic materials enables flexible storage of various charged ions (for example, H+, Li+, Na+, K+, Zn2+, Mg2+, and Ca2+, and so on). We offer a comprehensive overview of the progress of organics containing carbonyls for energy storage and conversion in aqueous electrolytes, including applications in aqueous batteries as solid‐state electrodes, in flow batteries as soluble redox species, and in water electrolysis as redox buffer electrodes. The advantages of organic electrodes are summarized, with a discussion of the challenges remaining for their practical application.
CoII Complexes as Liposomal CEST Agents
Authors: Abozeid Samira M. , Asik Didar , Sokolow Gregory E. , Lovell Jonathan F. , Nazarenko Alexander Y. , Morrow Janet R. 
Published: April 2020

AbstractThree paramagnetic CoII macrocyclic complexes containing 2‐hydroxypropyl pendant groups, 1,1′,1′′,1′′′‐(1,4,8,11‐tetraazacyclotetradecane‐1,4,8,11‐tetrayl)tetrakis‐ (propan‐2‐ol) ([Co(L1)]2+, 1,1′‐(4,11‐dibenzyl‐1,4,8,11‐tetraazacyclotetradecane‐1,8‐diyl)bis(propan‐2‐ol) ([Co(L2)]2+), and 1,1′‐(4,11‐dibenzyl‐1,4,8,11‐tetraazacyclotetradecane‐1,8‐diyl)bis(octadecan‐2‐ol) ([Co(L3)]2+) were synthesized to prepare transition metal liposomal chemical exchange saturation transfer (lipoCEST) agents. In solution, ([Co(L1)]2+) forms two isomers as shown by 1H NMR spectroscopy. X‐ray crystallographic studies show one isomer with 1,8‐pendants in cis‐configuration and a second isomer with 1,4‐pendants in trans‐configuration. The [Co(L2)]2+ complex has 1,8‐pendants in a cis‐configuration. Remarkably, the paramagnetic‐induced shift of water 1H NMR resonances in the presence of the [Co(L1)]2+ complex is as large as that observed for one of the most effective LnIII water proton shift agents. Incorporation of [Co(L1)]2+ into the liposome aqueous core, followed by dialysis against a solution of 300 mOsm L−1 produces a CEST peak at 3.5 ppm. Incorporation of the amphiphilic [Co(L3)]2+ complex into the liposome bilayer produces a more highly shifted CEST peak at −13 ppm. Taken together, these data demonstrate the feasibility of preparing CoII lipoCEST agents.
Incorporating Rare‐Earth Terbium(III) Ions into Cs2AgInCl6:Bi Nanocrystals toward Tunable Photoluminescence
Authors: Liu Ying , Rong Ximing , Li Mingze , Molokeev Maxim S. , Zhao Jing , Xia Zhiguo 
Published: April 2020

AbstractThe incorporation of impurity ions or doping is a promising method for controlling the electronic and optical properties and the structural stability of halide perovskite nanocrystals (NCs). Herein, we establish relationships between rare‐earth ions doping and intrinsic emission of lead‐free double perovskite Cs2AgInCl6 NCs to impart and tune the optical performances in the visible light region. Tb3+ ions were incorporated into Cs2AgInCl6 NCs and occupied In3+ sites as verified by both crystallographic analyses and first‐principles calculations. Trace amounts of Bi doping endowed the characteristic emission (5D4→7F6‐3) of Tb3+ ions with a new excitation peak at 368 nm rather than the single characteristic excitation at 290 nm of Tb3+. By controlling Tb3+ ions concentration, the emission colors of Bi‐doped Cs2Ag(In1−xTbx)Cl6 NCs could be continuously tuned from green to orange, through the efficient energy‐transfer channel from self‐trapped excitons to Tb3+ ions. Our study provides the salient features of the material design of lead‐free perovskite NCs and to expand their luminescence applications.
Thoughts on What Chemists Can Contribute to Fighting SARS‐CoV‐2 – A Short Note on Hand Sanitizers, Drug Candidates and Outreach
Authors: Opatz Till , Senn‐Bilfinger Joerg , Richert Clemens 
Published: April 2020

AbstractThe SARS‐CoV‐2 outbreak causing the respiratory disease COVID‐19 has left many chemists in academia without an obvious option to contribute to fighting the pandemic. Some of our recent experiences indicate that there are ways to overcome this dilemma. A three‐pronged approach is proposed.
Topology‐Templated Synthesis of Crystalline Porous Covalent Organic Frameworks
Authors: Jin Enquan , Geng Keyu , Lee Ka Hung , Jiang Weiming , Li Juan , Jiang Qiuhong , Irle Stephan , Jiang Donglin 
Published: April 2020

AbstractA strategy is presented for the synthesis of crystalline porous covalent organic frameworks via topology‐templated polymerization. The template is based on imine‐linked frameworks and their (001) facets seed the C=C bond formation reaction to constitute 2D sp2carbon‐conjugated frameworks. This strategy is applicable to templates with different topologies, enables designed synthesis of frameworks that cannot be prepared via direct polymerization, and creates a series of sp2carbon frameworks with tetragonal, hexagonal, and kagome topologies. The sp2carbon frameworks are highly luminescent even in the solid state and exhibit topology‐dependent π transmission and exciton migration; these key fundamental π functions are unique to sp2carbon‐conjugated frameworks and cannot be accessible by imine‐linked frameworks, amorphous analogues, and 1D conjugated polymers. These results demonstrate an unprecedented strategy for structural and functional designs of covalent organic frameworks.
Artificial Splitting of a Non‐Ribosomal Peptide Synthetase by Inserting Natural Docking Domains
Authors: Kegler Carsten , Bode Helge B. 
Published: April 2020

AbstractThe interaction in multisubunit non‐ribosomal peptide synthetases (NRPSs) is mediated by docking domains that ensure the correct subunit‐to‐subunit interaction. We introduced natural docking domains into the three‐module xefoampeptide synthetase (XfpS) to create two to three artificial NRPS XfpS subunits. The enzymatic performance of the split biosynthesis was measured by absolute quantification of the products by HPLC‐ESI‐MS. The connecting role of the docking domains was probed by deleting integral parts of them. The peptide production data was compared to soluble protein amounts of the NRPS using SDS‐PAGE. Reduced peptide synthesis was not a result of reduced soluble NRPS concentration but a consequence of the deletion of vital docking domain parts. Splitting the xefoampeptide biosynthesis polypeptide by introducing docking domains was feasible and resulted in higher amounts of product in one of the two tested split‐module cases compared to the full‐length wild‐type enzyme.
A Concise Total Synthesis of (+)‐Waihoensene Guided by Quaternary Center Analysis
Authors: Peng Cheng , Arya Piyush , Zhou Zhiyao , Snyder Scott A. 
Published: April 2020

AbstractThe four contiguous all‐carbon quaternary centers of waihoensene, coupled with the absence of any traditional reactive functional groups other than a single alkene, render it a particularly challenging synthetic target among angular triquinane natural products. Here, we show that its polycyclic frame can be assembled concisely by using a strategically chosen quaternary center to guide the formation of the other three through judiciously selected C−C bond formation reactions. Those events, which included a unique Conia‐ene cyclization and a challenging Pauson–Khand reaction, afforded a 17‐step synthesis of the molecule in enantioenriched form.
SLIM: A Short‐Linked, Highly Redox‐Stable Trityl Label for High‐Sensitivity In‐Cell EPR Distance Measurements
Authors: Fleck Nico , Heubach Caspar A. , Hett Tobias , Haege Florian R. , Bawol Pawel P. , Baltruschat Helmut , Schiemann Olav 
Published: April 2020

AbstractThe understanding of biomolecular function is coupled to knowledge about the structure and dynamics of these biomolecules, preferably acquired under native conditions. In this regard, pulsed dipolar EPR spectroscopy (PDS) in conjunction with site‐directed spin labeling (SDSL) is an important method in the toolbox of biophysical chemistry. However, the currently available spin labels have diverse deficiencies for in‐cell applications, for example, low radical stability or long bioconjugation linkers. In this work, a synthesis strategy is introduced for the derivatization of trityl radicals with a maleimide‐functionalized methylene group. The resulting trityl spin label, called SLIM, yields narrow distance distributions, enables highly sensitive distance measurements down to concentrations of 90 nm, and shows high stability against reduction. Using this label, the guanine‐nucleotide dissociation inhibitor (GDI) domain of Yersinia outer protein O (YopO) is shown to change its conformation within eukaryotic cells.
Metal‐Deficient Supramolecule Based on a Fivefold‐Symmetric Building Block
Authors: Schiller Jana , Peresypkina Eugenia , Virovets Alexander V. , Scheer Manfred 
Published: April 2020

AbstractAn unprecedented cationic supramolecule [(Cp′′Fe(η5‐P5))12{CuNCMe}8]8+ 2.66 nm in diameter was selectively isolated as a salt of the weakly coordinating anion [Al{OC(CF3)3}4]− for the first time and characterized by X‐ray structure analysis, PXRD, NMR spectroscopy, and mass spectrometry. Its metal‐deficient core contains the lowest possible number of Cu atoms to connect 12 pentaphosphaferrocene units, providing a supramolecule with fullerene topology which, topologically, also represents the simplest homologue in the family of metal‐deficient pentaphosphaferrocene‐based supramolecules [{CpRFe(η5‐P5)}12(CuX)20−n]. The 12 vacant metal sites between the cyclo‐P5 rings, the largest number attained to date, make this compound a facile precursor for potential inner and outer modifications of the core as well as for functionalization via the substitution of labile acetonitrile ligands.
3D numerical simulation of radionuclides atmospheric dispersion in Chinese nuclear safety regulation
Authors: Wang Xuan , Wang Yichuan , Liao Yunxuan , Wang Dezhong , Du Fenglei , Ma Yuanwei , Wang Bo 
Published: April 2020

AbstractFor increasing the regulation accuracy and efficiency, commercial computational fluid dynamics (CFD) software Fluidyn‐PANACHE was induced to assist in the analysis of typical radionuclides atmospheric diffusion for the Chinese nuclear safety regulation. The atmospheric dispersion simulation system that used three‐dimensional CFD methods, combined three‐dimensional GIS, and multiple technical methods, such as boundary values calculation, body‐fitting mesh generation, and refinement, was established to simulate and discuss the local wind field characteristics, pollutant transportation, and spatial distribution patterns under spot or constant meteorological conditions following unsteady (real time) or steady methods, respectively. This method can be used to reasonably simulate the turbulent and circumferential flow around large cooling towers in the inland nuclear power plant, compensating the shortage in subtleness of the standard Gaussian model, as well as shortage in realizing multiwind direction simulation in the calculation by the traditional CFD model. The calculation results of annual average atmospheric dispersion factor under normal operation indicated the seasonal differences, with maximum average dispersion factor in autumn, which were consistent with those suggested by Gaussian mixture model. Consequently, it is reasonable to avoid refueling overhauling in autumn to diminish pollution. The CFD numerical simulation method, which has a high agreement with the results of physical tests such as wind tunnel test, provides a new reference for the nuclear safety review of inland nuclear facilities in China.
The effects of modified zinc oxide nanoparticles on the mechanical/thermal properties of epoxy resin
Authors: Baghdadi Yasmine N. , Youssef Lucia , Bouhadir Kamal , Harb Mohammad , Mustapha Samir , Patra Digambara , Tehrani‐Bagha Ali R. 
Published: April 2020

AbstractCharacterized by its strength, durability, and thermal properties, epoxy resin has been widely used as an adhesive, paint, and coating in many applications in the aerospace, civil and automotive industries. Despite this, the thermoset polymer resin has been known for its brittleness and low fracture resistance. This study focuses on the reinforcement of an epoxy resin system (diglycidyl ether of bisphenol A) with zinc oxide (ZnO) nanoparticles in their pristine form and a further modified form. The modification took place in two ways: coating with polydopamine (PDA) and covalently functionalizing them with (3‐aminopropyl)triethoxysilane (APTES) and (3‐glycidoxypropyl)trimethoxysilane (GPTMS). Therefore, four different types of nanoparticles were used: pristine ZnO, ZnO/PDA, ZnO/GPTMS, and ZnO/APTES aiming to improve the interfacial bonding between the polymeric matrix and the reinforcement. Thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy, and scanning electron microscopy characterization and imaging techniques were used to prove that the ZnO nanoparticles were successfully modified prior to manufacturing the epoxy composites. While tensile testing showed that using pristine ZnO increases the composite's strength by 32.14%, the fracture toughness of the resin was improved by 9.40% when reinforced with ZnO functionalized with APTES. TGA showed that the addition of functionalized nanoparticles increases the material's degradation temperature by at most 7.31 ± 4.9°C using ZnO/APTES. Differential scanning calorimetry and dynamic mechanical analysis testing proved that the addition of any type of nanoparticles increases the resin's glass transition temperature by as much as 7.83°C (ZnO/APTES).
Glycosylation as a tool for rational vaccine design
Authors: Hariharan Vivek , Kane Ravi S. 
Published: April 2020

AbstractThe discovery of broadly neutralizing antibodies that can neutralize multiple strains or subtypes of a pathogen has renewed interest in the development of broadly protective vaccines. To that end, there has been an interest in designing immunofocusing strategies to direct the immune response to specific, conserved regions on antigenic proteins. Modulation of glycosylation is one such immunofocusing strategy; extensive glycosylation is often exploited by pathogens for immune evasion. Masking epitopes on protein immunogens with “self” glycans can also shield the underlying protein surface from humoral immune surveillance. We review recent advances in applying glycosylation as an immunofocusing tool. We also highlight recent interesting work in the HIV‐1 field involving the identification and elicitation of broadly neutralizing antibodies that incorporate glycans into their binding epitopes.
The effect of positioning on maternal anatomy and hemodynamics during late pregnancy
Authors: Humphries Aimee , Thompson John M. D. , Stone Peter , Mirjalili Seyed Ali 
Published: April 2020

AbstractIntroductionSupine positioning during late pregnancy causes dramatic compression of maternal abdominal vasculature and is a risk factor for stillbirth. The azygos vein has been shown to provide collateral circulation in this scenario. There are many well‐known anatomical differences in abdominal vasculature between the left and right sides of the body. However, the effect of left and right positioning in pregnancy has not been well studied.Materials and MethodsAfter obtaining ethics approval, 10 women with uncomplicated pregnancies between 34 and 38 weeks gestation underwent magnetic resonance imaging in the left and right lateral positions. Phase contrast images were evaluated to measure blood flow through the abdominal aorta, inferior vena cava, and azygos vein.ResultsNo significant differences between left and right lateral positions were found in blood flow through the IVC at its formation (mean difference −0.15 L/min [CI −0.47, 0.18], p = .34) or through the azygos vein (mean difference 0.02 L/min [CI −0.22, 0.26], p = .87). Blood flow through the IVC just above the level of the renal veins was found to be reduced by 35% in the right lateral position when compared to the left (mean difference 1.01 L/min [CI 0.25, 1.43], p = .03). There were no significant differences in cardiac output or blood flow through the abdominal aorta.ConclusionsWhile it was noted that blood flow through the IVC immediately above the level of the renal veins was reduced in the right lateral position, this did not appear to impact significantly on maternal cardiac output or blood flow through the azygos vein.