bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lipidic Aminoglycoside Derivatives: A New Class of Immunomodulators Inducing a Potent Innate Immune Stimulation
Authors: Colombani Thibault , Haudebourg Thomas , Decossas Marion , Lambert Olivier , Ada Da Silva Grace , Altare Frederic , Pitard Bruno 
Published: July 2019

AbstractDevelopment of simple and fully characterized immunomodulatory molecules is an active area of research to enhance current immunotherapies. Monophosphoryl lipid A (MPL), a nontoxic lipidic derivative from bacteria, is the first and currently only adjuvant approved in humans. However, its capacity to induce a potent response against weak immunogenic tumoral‐associated antigens remains limited. Herein, a new generation of lipidic immunomodulators to conduct a structure–activity relationship study to determine the minimal structural elements conferring immunomodulatory properties is introduced. Two lead molecules characterized by a short succinyl linker between two oleyl chains and a polar headgroup consisting of either naturally occurring tobramycin (DOST) or kanamycin (DOSK) are identified. These two lipoaminoglycosides self‐assemble in very small vesicles. In a wide variety of cells including 3D human cell culture, DOST and DOSK induce the upregulation of proinflammatory cytokines and interferon‐inducible proteins in a dose and time‐dependent manner via a caveolae‐dependent proinflammatory mechanism and phosphatidylinositol phospholipase C activation. Furthermore, after intratumoral administration, these lipoaminoglycosides induce an efficient immune response leading to significant antitumor activity in a mouse breast cancer model. Altogether, these findings indicate that DOST and DOSK are two groundbreaking synthetic lipid immunostimulators that can be used as adjuvants to enhance current immunotherapeutic treatments.
Efficient Red/Near‐Infrared‐Emissive Carbon Nanodots with Multiphoton Excited Upconversion Fluorescence
Authors: Liu Kai‐Kai , Song Shi‐Yu , Sui Lai‐Zhi , Wu Si‐Xuan , Jing Peng‐Tao , Wang Ruo‐Qiu , Li Qing‐Yi , Wu Guo‐Rong , Zhang Zhen‐Zhong , Yuan Kai‐Jun , Shan Chong‐Xin 
Published: July 2019

AbstractRed/near‐infrared (NIR) emissive carbon nanodots (CNDs) with photoluminescence (PL) quantum yield (QY) of 57% are prepared via an in situ solvent‐free carbonization strategy for the first time. 1‐Photon and 2‐photon cellular imaging is demonstrated by using the CNDs as red/NIR fluorescence agent due to the high PL QY and low biotoxicity. Further study shows that the red/NIR CNDs exhibit multiphoton excited (MPE) upconversion fluorescence under excitation of 800–2000 nm, which involves three NIR windows (NIR‐I, 650–950 nm; NIR‐II, 1100–1350; NIR‐III, 1600–1870 nm). 2‐Photon, 3‐photon, and 4‐photon excited fluorescence of the CNDs under excitation of different wavelengths is achieved. This study develops an in situ solvent‐free carbonization method for efficient red/NIR emissive CNDs with MPE upconversion fluorescence, which may push forward the application of the CNDs in bioimaging.
Multifunctional Magnetocontrollable Superwettable‐Microcilia Surface for Directional Droplet Manipulation
Authors: Ben Shuang , Zhou Tiantian , Ma Han , Yao Jinjia , Ning Yuzhen , Tian Dongliang , Liu Kesong , Jiang Lei 
Published: July 2019

AbstractIn nature, fluid manipulations are ubiquitous in organisms, and they are crucial for many of their vital activities. Therefore, this process has also attracted widescale research attention. However, despite significant advances in fluid transportation research over the past few decades, it is still hugely challenging to achieve efficient and nondestructive droplet transportation owing to contamination effects and controllability problems in liquid transportation applications. To this end, inspired by the motile microcilia of micro‐organisms, the superhydrophobicity of lotus leaves, the underwater superoleophobicity of filefish skin, and pigeons' migration behavior, a novel manipulation strategy is developed for droplets motion. Specifically, herein, a superwettable magnetic microcilia array surface with a structure that is switchable by an external magnetic field is constructed for droplet manipulation. It is found that under external magnetic fields, the superhydrophobic magnetic microcilia array surface can continuously and directionally manipulate the water droplets in air and that the underwater superoleophobic magnetic microcilia array surface can control the oil droplets underwater. This work demonstrates that the nondestructive droplet transportation mechanism can be used for liquid transportation, droplet reactions, and micropipeline transmission, thus opening up an avenue for practical applications of droplet manipulation using intelligent microstructure surfaces.
Quantifying the Nongeminate Recombination Dynamics in Nonfullerene Bulk Heterojunction Organic Solar Cells
Authors: Vollbrecht Joachim , Brus Viktor V. , Ko Seo‐Jin , Lee Jaewon , Karki Akchheta , Cao David Xi , Cho Kilwon , Bazan Guillermo C. , Nguyen Thuc‐Quyen 
Published: July 2019

AbstractIn this study, a comprehensive analytical model to quantify the total nongeminate recombination losses, originating from bimolecular as well as bulk and surface trap‐assisted recombination mechanisms in nonfullerene‐based bulk heterojunction organic solar cells is developed. This proposed model is successfully employed to obtain the different contributions to the recombination current of the investigated solar cells under different illumination intensities. Additionally, the model quantitatively describes the experimentally measured open‐circuit voltage versus light intensity dependence. Most importantly, it is possible to calculate the experimental results with the same fitting parameter values from the presented model. The validity of this model is also proven by a combination of other independent, steady‐state, and transient experimental techniques. This new powerful analytical tool will enable researchers in the photovoltaic community to take into account the synergetic contribution from all relevant types of nongeminate recombination losses in different optoelectronic systems and target their analysis of recombination dynamics at any operating voltage.
Preparation and photocatalytic activity of carbon dot/Ag/AgCl
Authors: Song Limin , Zhao Xiaofei , Zhang Shujuan 
Published: July 2019

CD (carbon dot)/Ag/AgCl compound photocatalysts with different compounding degrees were prepared via a precipitation method, and their physiochemical properties were characterized by X‐ray diffraction, FE‐SEM, UV–vis and the like. Through the degradation experiment of methyl orange (MO), the effects of different compounding amount and methyl orange concentration on photocatalytic degradation were investigated to find the best ratio. It was found the photocatalytic activity of CD/Ag/AgCl was significantly higher than Ag/AgCl, and the best compounding dosage was 6 mg/l carbon dot. The degradation rate of CD/Ag/AgCl was lower when the initial MO concentration was higher. Five repeated experiments were conducted to test the stability of the catalysts, and showed the MO degradation rates were all above 85%, indicating the CD/Ag/AgCl compound photocatalysts all showed high stability and repeatability. The reaction mechanism of CD/Ag/AgCl photocatalyst was studied by electrochemical experiments and ESR experiments. The results show that the doping of CD effectively improves the photocatalytic degradation ability of MO.
Isothermal Curing Kinetics of Epoxidized Fatty Acid Methyl Esters and Triacylglycerols
Authors: Li Yonghui , Li Cong , Sun Xiuzhi Susan 
Published: July 2019

AbstractPlant oil triacylglycerols are attractive renewable resources for biobased epoxy resins. We investigated the curing kinetics of three model epoxidized fatty acid methyl esters and representative epoxidized triacylglycerols with varied epoxide functionalities and distributions in the presence of a latent cationic initiator. Isothermal differential scanning calorimetry (DSC) was used to analyze the curing kinetics of the epoxy systems, and kinetic parameters (i.e., rate constants, reaction orders) were determined. Both epoxidized fatty esters and triacylglycerols followed the autocatalytic curing mechanism, and the DSC data were analyzed according to the Kamal autocatalytic model. Epoxidized methyl linoleate (EMLO) had the highest maximum curing rate, followed by epoxidized methyl linolenate (EMLON), and epoxidized methyl oleate (EMO) had the lowest maximum curing rate. We conclude that EMLO with two epoxide groups has the highest reactivity in this curing system, while the EMO with one epoxide group has the lowest reactivity. For epoxidized triacylglycerols, epoxidized camelina oil had the highest curing reactivity at higher temperatures, followed by epoxidized linseed oil and soybean oil.
Multiple imputation in the presence of an incomplete binary variable created from an underlying continuous variable
Authors: Grobler Anneke C. , Lee Katherine 
Published: July 2019

AbstractMultiple imputation (MI) is used to handle missing at random (MAR) data. Despite warnings from statisticians, continuous variables are often recoded into binary variables. With MI it is important that the imputation and analysis models are compatible; variables should be imputed in the same form they appear in the analysis model. With an encoded binary variable more accurate imputations may be obtained by imputing the underlying continuous variable. We conducted a simulation study to explore how best to impute a binary variable that was created from an underlying continuous variable. We generated a completely observed continuous outcome associated with an incomplete binary covariate that is a categorized version of an underlying continuous covariate, and an auxiliary variable associated with the underlying continuous covariate. We simulated data with several sample sizes, and set 25% and 50% of data in the covariate to MAR dependent on the outcome and the auxiliary variable. We compared the performance of five different imputation methods: (a) Imputation of the binary variable using logistic regression; (b) imputation of the continuous variable using linear regression, then categorizing into the binary variable; (c, d) imputation of both the continuous and binary variables using fully conditional specification (FCS) and multivariate normal imputation; (e) substantive‐model compatible (SMC) FCS. Bias and standard errors were large when the continuous variable only was imputed. The other methods performed adequately. Imputation of both the binary and continuous variables using FCS often encountered mathematical difficulties. We recommend the SMC‐FCS method as it performed best in our simulation studies.
Can adopting ambitious environmental sustainability initiatives lead to business failures? An analytical framework
Authors: Amankwah‐Amoah Joseph , Syllias Johnny 
Published: July 2019

AbstractDrawing on environmental sustainability orientation and business failure literature, we examined a thought‐provoking question: “Can adopting ambitious environmental sustainability initiatives lead to business failures and under what conditions is this more likely?” To address this question, we developed an analytical framework that provides new insights into how voluntary environmental initiatives affect the business environment and firm competitiveness. This paper also yields new insights on the features that emerge at adopting environmental initiatives–business failure nexus: from greening to growing, from greening to sustaining, from greening to constraining, and from greening to collapsing. Accordingly, the study accounts for the conditions under sustainability initiatives, and a variety of complex contextual factors are likely to culminate in closures of small and medium‐sized enterprises (SMEs). Although many top executives, entrepreneurs, and managers view implementation of environmental initiatives as tantamount to superior firm performance, the paper highlighted the effects of resource constraints and vulnerabilities of SMEs and new firms during the early stage of development, and therefore, pursuing aggressive green initiatives could minimize their life chances. Implications for scholars and practising managers are discussed.
Layer‐Wise Titania Growth Within Dimeric Organic Functional Group Viologen Periodic Mesoporous Organosilica as Efficient Photocatalyst for Oxidative Formic Acid Decomposition
Authors: Ahadi Arefeh , Alamgholiloo Hassan , Rostamnia Sadegh , Liu Xiao , Shokouhimehr Mohammadreza , Alonso Diego A. , Luque Rafael 
Published: July 2019

Abstractbridge dimeric organic functional group viologen PMOs synthesized via layer by layer growth on titania (TiO2) has been unprecedently prepared as stable periodic mesoporous organosilica using surfactant under mild acidic conditions. The layer by layer TiO2 incorporation within the prepared organic functional group viologen‐PMO could successfully develop a new type of hybrid photo‐oxidation system for the mineralization of formic acid under sunlight irradiation conditions.
Operando XAS/XRD and Raman Spectroscopic Study of Structural Changes of the Iron Molybdate Catalyst during Selective Oxidation of Methanol
Authors: Gaur Abhijeet , Schumann Max , Raun Kristian Viegaard , Stehle Matthias , Beato Pablo , Jensen Anker Degn , Grunwaldt Jan‐Dierk , Høj Martin 
Published: July 2019

AbstractThe structural changes of an iron molybdate/molybdenum oxide (Mo/Fe=2.0) catalyst for the selective oxidation of methanol to formaldehyde were studied using combined operando X‐ray absorption spectroscopy (XAS) and X‐ray diffraction (XRD) as well as operando Raman spectroscopy. Under operating conditions, the Mo K‐edge XANES spectra showed a transition from a mixture of α‐MoO3 and Fe2(MoO4)3 towards only Fe2(MoO4)3. XRD and Raman spectroscopy also showed disappearance of the α‐MoO3 phase with time on stream. The results evidenced that the α‐MoO3 component evaporated completely, while the Fe2(MoO4)3 component remained stable. This was linked to a decrease in catalytic activity. Further studies unraveled that the rate of α‐MoO3 evaporation increased with increasing MeOH concentration, decreasing O2 concentration and increasing temperature. The simultaneous measurements of catalytic activity and spectroscopy allowed to derive a structure‐activity relationship showing that α‐MoO3 evaporation needs to be prevented to optimize MoO3‐based catalysts for selective oxidation of methanol.
Effect of Empty Fruit Bunch in Calcium Oxide for Cyclic CO2 Capture
Authors: Mohamed Mustakimah , Yusup Suzana , Loy Adrian Chun Minh 
Published: July 2019

AbstractEmpty fruit bunch (EFB) is utilized to increase the CO2 capture capacity and cyclic stability of calcium oxide (CaO) prepared from cockle shells (CS). The cyclic reaction of calcination and carbonation reaction was performed in pure N2 environment and in the presence of CO2 in N2, respectively. The EFB in CS modified the pore structural properties, morphology, and composition of the pristine CaO. Higher EFB loading in CS reduced the CaO composition but improved the CO2 capture capacity and cyclic stability during cyclic CO2 capture.
Modeling of Slug Velocity and Pressure Drop in Gas‐Liquid‐Liquid Slug Flow
Authors: Hellmann David , Agar David W. 
Published: July 2019

AbstractGas‐liquid‐liquid slug flow in a capillary reactor is a promising new concept that allows one to incorporate gas‐liquid reaction, liquid‐liquid extraction, and facile catalyst separation in a single unit. In order to assess the performance of a gas‐liquid‐liquid slug flow reactor, it is necessary to predict the slug velocity and pressure drop to ascertain residence times and reaction rates. New empirical models for velocity and pressure drop were developed based on existing models for two‐phase gas‐liquid and liquid‐liquid slug flows, and these were validated experimentally.
Exploring the Steady Operation of a Continuous Pilot Plant for the Di‐Nitration Reaction
Authors: Sharma Mrityunjay , Acharya Roopashree B. , Kulkarni Amol A. 
Published: July 2019

AbstractContinuous‐flow synthesis of the selective herbicide pendimethalin was demonstrated in both a laboratory‐scale and a pilot‐scale reactor using only concentrated nitric acid as nitrating agent. The di‐nitration reaction follows second‐order kinetics where the reaction is first order with respect to both reactant and nitric acid. The pinched‐tube reactor was chosen for pilot‐scale reactor fabrication due to its excellent mixing and mass transfer characteristics compared to a straight‐tube reactor. The estimated mass transfer coefficient showed similar nature in the laboratory‐scale and the pilot‐scale pinched‐tube reactor, ensuring similar performance at the pilot scale. Di‐nitration in continuous flow, inline quenching, extraction, and phase separation are some of the salient features of the developed pilot plant. The importance of the start‐up time for achieving steady state in the flow system at the large scale is highlighted.
Light‐Induced Dimerization Approaches to Control Cellular Processes
Authors: Klewer Laura , Wu Yao‐Wen 
Published: July 2019

AbstractLight‐inducible approaches provide a means to control biological systems with spatial and temporal resolution that is unmatched by traditional genetic perturbations. Recent developments of optogenetic and chemo‐optogenetic systems for induced proximity in cells facilitate rapid and reversible manipulation of highly dynamic cellular processes and have become valuable tools in diverse biological applications. New expansions of the toolbox facilitate control of signal transduction, genome editing, “painting” patterns of active molecules onto cellular membranes, and light‐induced cell cycle control. A combination of light‐ and chemically induced dimerization approaches have also seen interesting progress. Herein, an overview of optogenetic systems and emerging chemo‐optogenetic systems is provided, and recent applications in tackling complex biological problems are discussed.
Computational Investigations of Heme Carbenes and Heme Carbene Transfer Reactions
Authors: Zhang Yong 
Published: July 2019

AbstractEngineered heme proteins and biomimetic iron porphyrins have been found to possess excellent catalytic properties for numerous carbene transfer reactions. Computational studies, including the use of DFT calculations and molecular dynamics simulations, have been employed to help understand some important mechanistic aspects of heme carbene transfer reactions. This review summarizes advances in the computational results published in the following two areas: 1) the electronic and geometric structures of heme carbenes; spectroscopic properties; and effects of carbene substituent, porphyrin substituent, axial ligand, and spin state on heme carbene formation; and 2) mechanisms of heme carbenoid X−H (X=C, Si, B, N, S) insertions and cyclopropanation, including effects of heme carbene structural components and protein environment, as well as oxidation state and spin state. A brief outlook of future development is also addressed.
Solid–Gas Phase Synthesis of Coordination Networks by Using Redox‐Active Ligands and Elucidation of Their Oxidation Reaction
Authors: Den Taizen , Usov Pavel M. , Kim Jaejun , Hashizume Daisuke , Ohtsu Hiroyoshi , Kawano Masaki 
Published: July 2019

AbstractFormation of coordination networks is a complex process affected by a multitude of factors. Many synthetic strategies have been developed that attempt to control these factors and direct the structure of the final product. Coordination bond formation and structural assembly processes, however, typically take place either in the solution or solid states. In comparison, gas‐phase network synthesis remains largely unexplored. Herein, two new two‐dimensional coordination networks are obtained from the solid–gas phase reaction between ZnX2 (X=I, Br) and the redox‐active 2,5,8‐tri(4‐pyridyl)1,3‐diazaphenalene (HTPDAP) ligand. Their structures were solved by ab initio powder X‐ray diffraction analysis and feature a novel Zn halide trimeric cluster. This strategy is contrasted with a conventional solvothermal synthesis, which led to a one‐dimensional coordination polymer instead. The intrinsic electroactive properties of these materials were probed by solid‐state cyclic voltammetry measurements, which revealed the presence of HTPDAP and halide‐based processes. Chemical oxidation of the two‐dimensional networks by using NOPF6 agent, unexpectedly, led to the formation of a nitrated analog of HTPDAP, the PF6− salt of diprotonated 4,6,7,9‐tetranitro‐2,5,8‐tris(4‐pyridyl)diazaphenalene cation (denoted N‐TPDAP), which was isolated and characterized. These results provide deeper insights into the oxidation process of HTPDAP‐containing networks and uncover unique redox‐induced chemical transformations.
Tuneable Redox Chemistry and Electrochromism of Persistent Symmetric and Asymmetric Azine Radical Cations
Authors: Werr Marco , Kaifer Elisabeth , Wadepohl Hubert , Himmel Hans‐Jörg 
Published: July 2019

AbstractMolecular organic radicals have been intensively studied in the last decades, due to their interesting optical, magnetic and redox properties. Here we report the synthesis and characterisation of persistent organic radicals from one‐electron oxidation of redox‐active azines (RAAs), composed of two guanidinyl or related groups. By connecting two different groups together, asymmetric compounds result. In this way a series of compounds with varying redox potential is obtained that could be oxidised reversibly to the mono‐ and the dicationic charge states. The accessible redox states were fully determined by chemical redox reactions. The standard Gibbs free energy change for disproportionation of the radical monocation into the dication and the neutral molecule in solution, estimated from cyclovoltammetric measurements, varies between 43 and 71 kJ mol−1. While the neutral RAAs absorb predominately UV light, the radical monocations display strong absorptions covering almost the entire visible region and extending for some compounds into the NIR region. A detailed analysis of this highly reversible electrochromism is presented, and the fast switching characteristics are demonstrated in an electrochromic test device.
Persistent Digermenes with Acyl and α‐Chlorosilyl Functionalities
Authors: Klemmer Lukas , Kaiser Yvonne , Huch Volker , Zimmer Michael , Scheschkewitz David 
Published: July 2019

AbstractWe report the preparation of α‐chlorosilyl‐ and acyl‐substituted digermenes. Unlike the corresponding transient disilenes, these species with a Ge=Ge double bond show an unexpectedly low tendency for cyclization, but in turn are prone to thermal Ge=Ge bond cleavage. Triphenylsilyldigermene has been isolated as a crystalline model compound, and is the first fully characterized example of a neutral digermene with an A2GeGeAB substitution pattern. Spectroscopic and computational evidence prove the constitution of 1‐adamantoyldigermene as a first persistent species with a heavy double bond conjugated with a carbonyl moiety.
Reusable Pd@PEG Catalyst for Aerobic Dehydrogenative C−H/C−H Arylations of 1,2,3‐Triazoles
Authors: Ferlin Francesco , Yetra Santhivardhana Reddy , Warratz Svenja , Vaccaro Luigi , Ackermann Lutz 
Published: July 2019

AbstractDehydrogenative C−H arylations of 1,2,3‐triazoles were accomplished with the aid of a reusable palladium catalyst in PEG. The widely applicable oxidative palladium catalysis enabled the synthesis of fully decorated 1,2,3‐triazoles with a broad functional‐group tolerance and ample substrate scope. The sustainability of the aerobic C−H arylation was reflected by the use of PEG as green reaction medium and demonstrated by recycling studies of the catalyst and the reaction medium.