bluuebunny/crossref_metadata_2025_split huggingface dataset:
Furfural and 5‐Hydroxymethylfurfural Production from Sugar Mixture Using Deep Eutectic Solvent/MIBK System
Authors: Rusanen Annu , Lappalainen Katja , Kärkkäinen Johanna , Lassi Ulla 
Published: October 2021

AbstractCholine chloride (ChCl) / glycolic acid (GA) deep eutectic solvent (DES) media with high water content but without any additional catalyst are introduced in furfural and 5‐hydroxymethylfurfural (HMF) production. The effects of water content, reaction time, and reaction temperature are investigated with two feedstocks: a glucose/xylose mixture and birch sawdust. Based on the results, 10 equivalent quantities of water (32.9 wt.%) were revealed to be beneficial for conversions without rupturing the DES structure. The optimal reaction conditions were 160 °C and 10 minutes for the sugar mixture and 170 °C and 10 minutes for birch sawdust in a microwave reactor. High furfural yields were achieved, namely 62 % from the sugar mixture and 37.5 % from birch sawdust. HMF yields were low, but since the characterization of the solid residue of sawdust, after DES treatment, was revealed to contain only cellulose (49 %) and lignin (52 %), the treatment could be potentially utilized in a biorefinery concept where the main products are obtained from the cellulose fraction. Extraction of products into the organic phase (methyl isobutyl ketone, MIBK) during the reaction enabled the recycling of the DES phase, and yields remained high for three runs of recycling.
Three reasons why expanded use of natural enemy solutions may offer sustainable control of human infections
Authors: Jones Isabel J. , Sokolow Susanne H. , De Leo Giulio A. 
Published: October 2021

Abstract

Many infectious pathogens spend a significant portion of their life cycles in the environment or in animal hosts, where ecological interactions with natural enemies may influence pathogen transmission to people. Yet, our understanding of natural enemy opportunities for human disease control is lacking, despite widespread uptake and success of natural enemy solutions for pest and parasite management in agriculture.

Here we explore three reasons why conserving, restoring or augmenting specific natural enemies in the environment could offer a promising complement to conventional clinical strategies to fight environmentally mediated pathogens and parasites. (a) Natural enemies of human infections abound in nature, largely understudied and undiscovered; (b) natural enemy solutions could provide ecological options for infectious disease control where conventional interventions are lacking; and, (c) many natural enemy solutions could provide important co‐benefits for conservation and human well‐being.

We illustrate these three arguments with a broad set of examples whereby natural enemies of human infections have been used or proposed to curb human disease burden, with some clear successes. However, the evidence base for most proposed solutions is sparse, and many opportunities likely remain undiscovered, highlighting opportunities for future research.

A free Plain Language Summary can be found within the Supporting Information of this article.
Response of grassland net primary productivity to dry and wet climatic events in four grassland types in Inner Mongolia
Authors: Hossain Md Lokman , Kabir Md Humayain , Nila Mst Umme Salma , Rubaiyat Ashik 
Published: October 2021

AbstractIncreasing frequency and intensity of climate extremes have profound impacts on grassland biodiversity functioning and stability. Using Moderate Resolution Imaging Spectroradiometer (MODIS) net primary productivity (NPP) data and standardized precipitation evapotranspiration index, we assessed the response of NPP to growing‐season and annual climate extremes and time‐lag of climatic conditions across four grassland types (meadow steppe, typical steppe, steppe desert, and desert steppe) in Inner Mongolia, China from the period 2000 to 2019. Results showed that annual NPP varied significantly across four grassland types, with the highest NPP in meadow steppe and the lowest in desert steppe. Annual NPP of all grassland types increased over the past 20 years, but NPP in meadow steppe and typical steppe decreased for the period 2012–2019. Irrespective of grassland type, the 1‐ and 2‐month time‐lag of climatic conditions showed significant effects on annual NPP. Growing‐season climate was found the better predictor of annual NPP in all grassland types than the annual climate. Compared with growing‐season normal climates, annual NPP was lowest in extreme dry events in all grasslands, while highest in extreme wet events in meadow steppe and typical steppe, and in moderate wet events in steppe desert and desert steppe. Typical steppe and steppe desert are highly vulnerable to the increasing intensity of climate extremes, as we found that the losses of NPP in these grasslands in extreme dry were almost double than that of moderate dry events. Surprisingly, for meadow steppe and desert steppe, the losses of NPP for both moderate and extreme dry events were almost the same, which highlights that a low‐intensity drought may have profound impacts on the annual NPP of these grasslands. The study provides the key insight in scientific basis to improve our understanding of the effects of climate extremes on grassland NPP, which is critical to sustainable management of grassland and maintain ecosystem stability.
Single‐point halogenation regulates supramolecular chirality in phenylalanine‐based co‐assembled systems
Authors: Zou Yunqing , Zhao Changli , Feng Chuanliang 
Published: October 2021

AbstractThe construction of chiral materials with precise chirality is of vital importance in biology and chemistry. Despite numerous chiral materials having been fabricated, it still remains a fundamental challenge to understand the chiral propensity with subtle changes of building blocks. Here, the chirality properties of an assembly from chiral phenylalanine gelators and achiral naphthalimide (NI) derivatives were successfully regulated, showing that a minimal difference on the fourth site of the halogenated NI induced great changes of the chirality characteristics of the assembly. The results suggested that hydrogen bonds and π–π stacking interactions are the driving forces of the assemblies, whereas different halogenations indeed lead to the subtle variety of hydrogen bonding interactions and stacking mode between the two molecules. This study provides feasible strategies for precisely modulating supramolecular chirality through single‐point halogenation. © 2021 Society of Industrial Chemistry.
Synthesis and optical properties of π‐conjugated polymers and oligomers bearing hexaphenylbenzene and tetraphenyl ethene units
Authors: Yamaguchi Isao , Fukumoto Daiki , Wang Aohan 
Published: October 2021

Abstractπ‐Conjugated polymers (CPs) and oligomers (COs) bearing hexaphenylbenzene (HPB) and tetraphenyl ethene (TPE) units were synthesized by Sonogashira and Suzuki–Miyaura coupling reactions. The optical properties of the CPs and COs were investigated by UV–vis, photoluminescence (PL), and fluorescence lifetime (τ) measurements. The PL intensities of the solutions of the CPs and COs synthesized by Sonogashira coupling were reduced upon addition of poor solvent like water, which is attributed to aggregation‐caused quenching. In contrast, the CP and COs bearing the TPE unit synthesized by Suzuki–Miyaura coupling exhibited aggregation‐induced emission enhancement in solution. This difference in fluorescence behavior is discussed herein in terms of the molecular sizes, conformations in solution, and τ values of the CPs and COs.
Is ResonantAcoustic Mixing® (RAM) a Game Changer for Manufacturing Solid Composite Rocket Propellants?
Authors: Wright Christopher J. , Wilkinson Peter J. , Gaulter Sally E. , Fossey Donald , Burn Andrew O. , Gill Philip P. 
Published: October 2021

AbstractThis study is a structured literature review of published ResonantAcoustic® Mixing (RAM) literature, considering the benefits and constraints of using RAM. Focussing on how this will affect the future production of rubbery composite rocket propellants. The main benefits of RAM were found to be shorter mixing time, versatility of mixing and ability to mix higher viscosities than conventional mixers. Facilitating the next generation of composite propellants with improved performance and mechanical properties. Mixed in‐situ RAM overcomes viscosity limitations by removing the casting process and has safety and environmental benefits, but does need to be tested at larger production scales. The implications of RAM production on the energetics qualification process was considered. A new framework was discussed based on understanding the entire product development process including ingredient properties, manufacturing processes, and linking this to product performance; through adoption of a digital twin approach with in‐situ monitoring. Future R&D focuses on process and material control through a validated model of the mixing mechanisms, linked to material properties and output performance. Validation with scaled up comparative studies and continuous in‐situ monitoring. A full list is provided in the conclusions. Overall RAM offers numerous benefits to mixing existing and new materials with large savings in time, cost, improved safety and is more environmentally friendly.
Neural‐network‐based control for discrete‐time nonlinear systems with denial‐of‐service attack: The adaptive event‐triggered case
Authors: Wang Xueli , Ding Derui , Ge Xiaohua , Han Qing‐Long 
Published: October 2021

AbstractThis article investigates a neural network (NN)‐based control problem for unknown discrete‐time nonlinear systems with a denial‐of‐service (DoS) attack and an adaptive event‐triggered mechanism (ETM). The considered DoS attacks are described by the occurrence frequency and durations and hence more general in comparison with existing stochastic models. To the addressed problem, a novel adaptive rule adjusting the triggering threshold of ETM is constructed to govern the communication schedule, and an NN‐based observer is designed to identify the system dynamics where a piecewise update rule of NN weights is adopted to handle the challenge of the complex time series coming from both ETM and DoS attacks. In light of this kind of protocol‐ and attack‐induced switched systems, a sufficient condition dependent on the occurrence frequency and durations of DoS attacks is elaborately established via the analysis of input‐to‐state stability. Furthermore, an iteration adaptive dynamic programming approach is proposed to handle the addressed control issue, and the boundedness is discussed to both the estimation errors of the Luenberger‐type observer and the identified errors of NN weights of observer networks as well as actor‐critic networks with the help of the Lyapunov theory. Finally, a simulation example is utilized to illustrate the usefulness of the proposed controller design scheme.
Microstructural, Thermal and Electrical Properties of Methyl Methacrylate and 1‐Hexene Copolymers Made by Dinuclear Ni‐Based Catalysts
Authors: Ahmed Zainab Zahid , Ahmadzadeh Hossein , Zohuri Gholam Hossein 
Published: October 2021

AbstractHerein, we investigate the dinuclearity effect of α‐diimine Ni‐based catalysts, N1and N2bearing different backbone on methyl methacrylate/1‐hexene (MM‐1H) copolymerization and characterize the copolymers microstructures using FT‐IR and NMR. The monomer reactivity ratio (r) is calculated using three different methods, a high reactivity ratio for MM (r1=9.9611), whereas a low reactivity ratio is obtained for 1H (r2=−0.0226). As determined by NMR analyses, up to 96 % of the MM incorporated into the main chain. Thermal copolymer properties are studied by DSC and TGA analyses, and the results are compared with those of Poly (methyl methacrylate) (PMMA). The higher content of MM in the copolymer backbone and the higher Tgfor the copolymer samples (95.5 to 105.6 °C) were obtained. TGA shows that the degradation temperature of copolymers with higher 1H content progression reduced by about 10 % weight‐loss for N1(327 to 240 °C) and N2(325 to 236 °C). We are using a novel method with a low‐cost and speedy determination of polymer conductivity in both solid and liquid phases, which indicates the semi‐conductivity property of poly(MM‐1H) using corona discharges under the air atmosphere. Synthesized graphene‐poly(MM‐1H) nanocomposite shows the electrical conductivity augment from 3.45 μS of the poly(MM‐1H) to 30.42 μS for its nanocomposite.
An Overview of Iridium‐Catalyzed Allylic Amination Reactions
Authors: Biya Elsa , Neetha Mohan , Anilkumar Gopinathan 
Published: October 2021

AbstractAmination reactions plays a paramount role as it finds wide applications in pharmaceuticals, production of natural compounds and in drug synthesis. Considering the wide tool chest of procedures, it is one of the key approaches to C−N bond construction. In recent years, substantial headway has been observed in reactions of these type and have progressed into vital assistance for building molecules in modern synthetic chemistry. Concerning the catalytic activity of Iridium complexes which are suitable for many organic transformations including amination reactions, studies on amination of allylic systems by Iridium catalysts are significant. This review concisely compiles information on Iridium‐catalyzed allylic amination, casing literature up to 2020.
Power Dependent Hot Carrier Cooling Dynamics in Trioctylphosphine Capped CsPbBr3 Perovskite Quantum Dots Using Ultrafast Spectroscopy
Authors: Kumar Virendra , Nagal Vandana , Srivastava Shubhda , Kumar Mahesh , Gupta Bipin K. , Hafiz Aurangzeb K. , Singh Kedar 
Published: October 2021

AbstractHerein, a strategy has been executed to reduce the trap states in as‐synthesized CsPbBr3 perovskite quantum dots (PQDs) by using the capping of trioctylphosphine (TOP) which is further evident by the ultrafast spectroscopic technique. Moreover, the excitation source powers and unvarying excitation energy‐dependent studies were carried out to compare the hot carrier (HC) cooling dynamics in the PQDs and TOP‐capped CsPbBr3 PQDs (TOP‐PQDs) to explain the diminution of trap states in TOP‐PQDs. The HC cooling time has been calculated and found that 469.2 fs for PQDs whereas 394.8 fs is for TOP‐PQDs, respectively. From these HC cooling times, it can be concluded that TOP‐PQDs is more capable to intensify the process of HC relaxation from the higher energy states to the conduction band and contribute to suppress the charge trappings that supports the radiative recombination, which demonstrates the enhancement in the PL intensity and PLQY (i. e., 98.8 %). Likewise, and simultaneously at the excitation wavelength e.g.,
, TOP‐PQDs show an improved ground state bleaching (GSB) intensity signal than PQDs at three excitation source powers
in the following order: TOP‐PQDs
PQDs
, TOP‐PQDs
PQDs
, and TOP‐PQDs
PQDs
, respectively.
Preparation and Research on the Optical Temperature Sensing Properties of Ho3+ doped NaY(MoO4)2 Phosphors
Authors: Tian Ye , Meng Qingyu , Zhang Liying , Sun Wenjun , Wang Changwen 
Published: October 2021

AbstractIn this work, NaY(MoO4)2: 5 % Ho3+ were synthesized successfully with sodium citrate as chelating agent by hydrothermal method. As X‐ray diffraction graphs showed, the samples were body‐centered quadrilateral structure. The Field‐emission Scanning Electron Microscope pictures demonstrated the morphology of the experimental samples changed with different amounts of sodium citrate. The temperature‐dependent emission spectra (293‐563 K) revealed different thermal quenching trends of the emission peaks from different energy levels (5F4/5S2→5I7, 5F4/5S2→5I8 and 5F5→5I8). The two groups of fluorescence intensity ratios (FIR) could be applied to temperature measurement (5F4/5S2→5I8 to 5F5→5I8 and 5F4/5S2→5I7 to 5F5→5I8). As sodium citrate content increased, the maximum values of relative sensitivity of the samples increased, among which the greatest one was 0.316 % K−1 (Cit3−/Re3+=2). In addition, the FIR had good repeatability in heating, cooling and heating again process that indicated the temperature sensing properties of the sample were steady. Since it was possible to characterize temperature with two sets of FIR, the samples could play a self‐calibrating character. Summing up the above, the NaY(MoO4)2 : 5 % Ho3+ phosphors were promising optical temperature sensing materials.
Adsorption of Iodine on Adamantane‐Based Covalent Organic Frameworks
Authors: Wu Zhineng , Wei Wei , Ma Jianguo , Luo Jianqiang , Zhou Yueming , Zhou Zhiyi , Liu Shujuan 
Published: October 2021

AbstractRadioactive iodine is severely hazardous to human health and the environment because of its high specific activity and environmental mobility. In this article, three covalent organic frameworks (COFs) (named as DbTd‐COF, DpTd‐COF, and DaTd‐COF) were prepared for the removal of iodine in both gas and solution states. The COFs were obtained by the solvothermal reaction of 1,3,5,7‐tetrakis (4‐formylphenyl) adamantane (TFPA) with benzidine, 2,5‐diaminopyridine, and p‐phenylenediamine, respectively. The obtained samples were characterized by SEM, FT‐IR, TGA, and nitrogen adsorption‐desorption analysis. The rigid linker of phenzyl chains helps to improve the stability of the polymer. DbTd‐COF and DaTd‐COF show excellent thermomechanical stability with a decomposition temperature of over 400 °C. DbTd‐COF and DaTd‐COF show good uptake capacities of 4.93 and 4.48 g g−1 for iodine vapor capture, respectively. DpTd‐COF shows a slightly smaller iodine uptake of 3.43 g g−1. XPS results indicated that iodine was captured in the form of its polyiodide anions. A better recyclability can be obtained after four cycle runs. In addition, DaTd‐COF shows good removal of iodine (concentration: 500 mg L−1) from cyclohexane solution with an adsorption capacity of 666.79 mg g−1.
An Alkoxy Modified N‐Heterocyclic Carbene‐Palladacycle: Synthesis, Characterization and Application towards Buchwald‐Hartwig and Suzuki‐Miyaura Coupling Reactions
Authors: Zuo Bin , Shao Han , Qu Erdong , Ma Yunhua , Li Wanfang , Huang Mingxian , Deng Qinyue 
Published: October 2021

AbstractA well‐defined N‐heterocyclic carbene‐palladacycles (NHC‐Pdcycle) by introducing alkoxy group was synthesized, and its structure was confirmed using single‐crystal X‐ray diffraction. The complex as catalyst exhibited high catalytic activity in Buchwald‐Hartwig and Suzuki‐Miyaura coupling reactions involving (hetero)aryl chlorides. Remarkably, the protocol with a wide range of substrate compatibility is suitable for the gram‐scale synthesis of Piribedil, a clinical drug for the treatment of Parkinson's disease, highlighting its potential applications in pharmaceutical synthesis.
Aerobic Dehydrogenative Coupling of Naphthols and Phenols with a Ru(OH)x/Al2O3 Catalyst under Continuous‐Flow Conditions
Authors: Masuda Koichiro , Chen Wenlong , Hayashi Kazushi , Shimada Shigeru , Onozawa Shun‐ya , Koumura Nagatoshi , Sato Kazuhiko , Kobayashi Shū 
Published: October 2021

AbstractDehydrogenative coupling reactions of naphthols and phenols were achieved with a heterogeneous catalyst, alumina‐supported ruthenium hydroxide (Ru(OH)x/Al2O3), using continuous‐flow conditions and aerobic oxygen as the sole oxidant. The reactions were operated continuously for more than 16 h with good reactivity and selectivity. The Ru catalyst could be recycled at least three times by a simple online washing/activation procedure without depackaging the catalyst cartridge. The reaction provided binaphthols and biphenols as valuable products for synthetic purpose and functional materials, while an over‐oxidized quinone was obtained with 2,6‐Di‐tert‐butylphenol; combining this reaction with catalytic hydrogenation under continuous‐flow conditions enabled smooth conversion of quinone to the 4,4′‐biphenol derivative, which is a member of an important class of compounds for liquid crystals, engineering plastics, and other functional materials.
Modification of Short Non‐Permeable Peptides to Increase Cellular Uptake and Cytostatic Activity of Their Conjugates
Authors: Yousef Mo'ath , Szabó Ildikó , Biri‐Kovács Beáta , Szeder Bálint , Illien Françoise , Sagan Sandrine , Bánóczi Zoltán 
Published: October 2021

AbstractCell‐penetrating peptides (CPPs) are well‐known delivery vectors, oligoarginines are an important class of CPPs, which was modified to increase the cellular uptake and change the internalization mechanism. A minimum number of four Arg residues was used and tetrarginine sequence was modified by 4‐((4‐(dimethylamino)phenyl)azo)benzoic acid (Dabcyl) and Trp(s). The Dabcyl group was attached to the N‐terminus, while peptides were different in the number and position of Trp in their sequence. Their internalization was studied on breast cancer cells (MCF‐7 and MDA‐MB‐231), and Chinese hamster ovary cells (CHO) using different fluorescence techniques. Our most active CPPs, Dabcyl‐RRWRRK and Dabcyl‐WRRRRK were conjugated to antitumor drugs, resulting in considerable cytostatic activity, especially on MDA‐MB‐231 cell lines. These newly developed cell‐penetrating tetrarginine derivatives may enter cells very efficiently, mainly by direct translocation and caveolae‐mediated endocytosis, thus they may be promising delivery vehicle. Tetragrinines are considered inefficient CPPs, but with our modifications, we rendered them effective.
Multi‐Functional Solid Additive Induced Favorable Vertical Phase Separation and Ordered Molecular Packing for Highly Efficient Layer‐by‐Layer Organic Solar Cells
Authors: Yu Runnan , Wu Guangzheng , Cui Yong , Wei Xueqi , Hong Ling , Zhang Tao , Zou Chao , Hu Siqian , Hou Jianhui , Tan Zhan'ao 
Published: October 2021

AbstractLayer‐by‐layer (LBL) deposition strategy enabling favorable vertical phase distributions has been regarded as promising candidates for constructing high‐efficient organic photovoltaic (OPV) cells. However, solid additives with the merits of good stability and reproducibility have been rarely used to fine‐tune the morphology of the LBL films for improved efficiency and stability. Herein, hierarchical morphology control in LBL OPV is achieved via a dual functional solid additive. Series of LBL devices are fabricated by introducing the solid additive individually or simultaneously to the donor or acceptor layer to clarify the functions of additives. Additive in the donor layer can facilitate the formation of preferable vertical component distribution, and that in the acceptor layer will enhance the molecular crystallinity for better charge transport properties. The optimized morphology ultimately contributed to high PCEs of 16.4% and 17.4% in the binary and quaternary LBL devices. This reported method provides an alternative way to controllably manipulate the morphology of LBL OPV cells.