bluuebunny/crossref_metadata_2025_split huggingface dataset:
Applications of Polymer Bioconjugates
Authors: Opsteen Joost A. , Abdelmohsen Loai K.E.A. , van Hest Jan C.M. 
Published: March 2022

Abstract
Inspired by natural functional polymers, which are often very well‐defined and bear high‐level of information, scientists have undertaken to develop synthetic replicas based on polymer bioconjugates, that can be harnessed for diverse applications. In this regard, excellent strategies that provide the necessary scope for the synthesis and utility of polymer bioconjugates have been developed. Detailed evaluation to determine the influence of chemical factors that impact polymers' synthesis, alongside physical aspects necessary for their utility have been carried out. In this chapter, we discuss the current methodologies that allow for controlled synthesis of polymer bioconjugates, as their application in the biomedical field.
Control of Polycondensation
Authors: Yokozawa Tsutomu , Ohta Yoshihiro 
Published: March 2022

Abstract
Polycondensation is an important method of polymerization that affords polymers containing functional groups and/or aromatic rings in the backbone, which serve as fibers, engineering plastics, electrical materials, and so on by virtue of their strong intermolecular forces. Most research had been centered on how to increase the molecular weight of polymers and how to synthesize a variety of condensation polymers. Lately, however, polycondensation has developed in many controlled ways. This article describes (i) stoichiometric‐imbalanced polycondensation, in which high‐molecular‐weight polymers are obtained even when one of the two monomers are used in excess, (s) sequence control of monomer units in the backbone, (ii) molecular weight and dispersity control in polycondensation which proceeds in chain‐growth polymerization manner like living polymerization to afford aromatic polyamides, π‐conjugated polymers, and so on, (iii) chain topology control for linear, cyclic, and hyperbranched polymers, and (iv) architectures containing condensation polymer such as block copolymer, star polymer, and graft copolymer from a combination of controlled polycondensation and another polymerization method.
Statistical, Alternating, and Gradient Copolymers
Authors: Klumperman Bert , Pfukwa Rueben , Lederer Albena 
Published: March 2022

AbstractStatistical and alternating copolymers are very common materials that have been investigated extensively over many decades. In this contribution, an overview of the synthesis, characterization, and application of such polymers is provided. In more recent times, with the advent of reversible deactivation radical polymerization, gradient copolymers have gained significant attention. Similarities and differences between the conventional copolymers and their gradient counterparts are discussed. Also here, the emphasis is on synthesis, characterization, and application of the materials.
Ionic and Coordination Ring‐Opening Polymerization
Authors: Penczek Stanislaw , Biela Tadeusz , Cypryk Marek , Duda Andrzej , Lapienis Grzegorz , Kubisa Przemyslaw , Pretula Julia , Slomkowski Stanislaw , Szymanski Ryszard 
Published: March 2022

AbstractThis article provides the up‐to‐date and comprehensive review (over 700 citations) of all the important subjects of the ring‐opening polymerization (ROP) methods of polymers syntheses. This is the method of synthesis of several important classes of polymers that cannot be prepared in a different way (e.g., polyethers). It also complements known methods of polycondensation and ROP often is the method of choice. ROP is particularly important in syntheses of the biodegradable polymers‐polylactide and poly(ε‐caprolactone), discussed in details. Applications of these polymers, as well as polysiloxanes in biomedical applications are irreplaceable in the modern medicine. Either as bulk polymers or as nano‐ and microspheres, described In this article separately.There are sections in the present version that were not presented in the previous editions. This is description of polyoxazolines, polymers with phosphorus atoms in the chains, as well as mentioned above polysiloxanes an microspheres. We introduced also section describing novel analytical methods, particularly useful in studies of polymers with various architectures (star shape, multibranched etc.).Besides the synthetic aspects of ROP, this article describes thermodynamics and kinetic features of the living/controlled polymerizations, particularly by activated monomer mechanism and importance of dormant polymers in precision syntheses of desired structures.
Determination of Bulk and Solution Morphologies by Transmission Electron Microscopy
Authors: Abetz Volker , Jinnai Hiroshi , Spontak Richard J. , Talmon Yeshayahu 
Published: March 2022

Abstract
This chapter presents electron microscopy with a focus on transmission electron microscopy (TEM) and its application to polymer systems. After an introduction, some background about the method is given before different techniques are presented in detail. These include the investigations of solid bulk systems and liquid phases together with the specific procedures of sample preparation, as well as 3‐dimensional tomography for the study of complex morphologies and analytical electron microscopy to visualize the spatial distribution of different chemical elements. Examples are given for all techniques with an emphasis on block copolymers or block copolymer‐containing systems, as this class of polymers exhibits structural features that are very well suited for studies by transmission electron microscopy.
Polymer Composites as Ablative Materials
Authors: Kumar Colonel Vijay , Gharde Swaroop , Kandasubramanian Balasubramanian 
Published: March 2022

Abstract
Ablative composites are highly endothermic sacrificial materials, which undergo ablation wherein the outer surface of the material degrades to form a carbonaceous layer, which isolates the underlying material from intense thermal‐heat‐flux environs. Successful utilization of thermosetting resins modified with varied inorganic fillers to tailor ablative polymer composites for thermal protection systems has accelerated extensive research for the development of new contemporary materials for vast space and defense applications. This article discusses various types of ablative materials, polymer composite‐based ablative materials, ablation mechanism, and applications of ablative materials. Resorcinol formaldehyde (RF) resins, which have a similar chemical backbone to the phenolic formaldehyde (PF) resins, possess several advantages which make it a contender for the next generation of ablative materials. The synthesis, testing, and characterization of RF resin‐based ablative polymer nanocomposites have also been presented in this article.
Synthetic Polymers with Finely Regulated Monomer Sequences: Properties and Emerging Applications
Authors: Laurent Eline , Szweda Roza , Lutz Jean‐François 
Published: March 2022

AbstractThe design of synthetic polymers with controlled monomer sequences is an important emerging trend in polymer science. This new field of research is bio‐inspired by sequence‐defined biopolymers such as proteins and nucleic acids. The chemical synthesis of nonnatural sequence‐controlled polymers (SCPs) has been described in several reviews. However, there is currently little information about the properties and applications of these polymers. In this context, the aim of this article is to give a comprehensive view on these aspects. After a general introduction and a short section about the synthesis of SCPs, the physicochemical properties of these synthetic macromolecules are described in detail. For instance, emphasis is put on the bulk and solution self‐assembly of SCPs. In the last part of this article, potential applications are reviewed and discussed. Overall, SCPs, which are more time‐consuming to synthesize than regular commodity polymers, are not meant to be used in high‐scale applications but more in specialty technologies with high‐added value. For instance, application areas such as data storage, anti‐counterfeiting technologies, catalysis, and photovoltaics are described in this article.
Synthetic Strategies Towards Cyclic Polymers
Authors: Jiang Yu , Ntetsikas Konstantinos , Polymeropoulos George , Zapsas George , Feng Xiaoshuang , Gnanou Yves , Hadjichristidis Nikos 
Published: March 2022

Abstract
Cyclic polymers have attracted considerable interest for their different physical properties compared to the corresponding linear polymers due to the lack of chain ends. The synthesis of cyclic macromolecules has always been a challenge for polymer scientists, mainly due to the difficulties in connecting the ends of the chain. In general, cyclic polymers are synthesized by ring‐closure or ‐expansion techniques, but the main challenge with both methods is the production of highly pure cyclic polymers. In the past two decades, significant developments have been reported, thanks to the advent of controlled polymerizations and efficient coupling reactions in organic chemistry. This article aims to provide a concise overview of the most critical and important synthetic contributions in this field of both ring‐closure and ‐expansion strategies.
Electron Redistributed S‐Doped Nickel Iron Phosphides Derived from One‐Step Phosphatization of MOFs for Significantly Boosting Electrochemical Water Splitting
Authors: Li Songsong , Wang Lu , Su Hui , Hong Anh N. , Wang Yanxiang , Yang Huajun , Ge Lei , Song Weiyu , Liu Jian , Ma Tianyi , Bu Xianhui , Feng Pingyun 
Published: March 2022

AbstractNonprecious transition metal‐organic frameworks (MOFs) are one of the most promising precursors for developing electrocatalysts with high porosity and structural rigidity. This study reports the synthesis of high efficiency electrocatalysts based on S‐doped NiFeP. MOF‐derived S‐doped NiFeP structure is synthesized by a one‐step phosphorization process with using S‐doped MOFs as the precursor, which is more convenient and environment friendly, and also helps retain the samples’ framework. The oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) performance of the NiFeP catalysts can be improved after partially replacing P by S due to the tunable electronic structure. The optimized CCS‐NiFeP‐10 reaches a current density of 10 mA cm–2 for OER with an overpotential of 201 mV and outperforms most NiFe‐based catalysts. The S doping plays an important role in tuning the ΔG values for intermediates formation in Ni atoms to a suitable value and exhibits a pronouncedly improved the OER performance. CCS‐NiFeP‐20 sample presents excellent HER performance due to the d‐band center downshifting from the Fermi level. When the voltage of the electrolytic cell is 1.50 V, a current density of 10 mA cm–2 can be obtained. This strategy paves the way for designing highly active none‐noble metal catalysts.
A Fully Solution‐Printed Photosynaptic Transistor Array with Ultralow Energy Consumption for Artificial‐Vision Neural Networks
Authors: Shi Jialin , Jie Jiansheng , Deng Wei , Luo Gan , Fang Xiaochen , Xiao Yanling , Zhang Yujian , Zhang Xiujuan , Zhang Xiaohong 
Published: March 2022

AbstractPhotosynaptic organic field‐effect transistors (OFETs) represent a viable pathway to develop bionic optoelectronics. However, the high operating voltage and current of traditional photosynaptic OFETs lead to huge energy consumption greater than that of the real biological synapses, hindering their further development in new‐generation visual prosthetics and artificial perception systems. Here, a fully solution‐printed photosynaptic OFET (FSP‐OFET) with substantial energy consumption reduction is reported, where a source Schottky barrier is introduced to regulate charge‐carrier injection, and which operates with a fundamentally different mechanism from traditional devices. The FSP‐OFET not only significantly lowers the working voltage and current but also provides extraordinary neuromorphic light‐perception capabilities. Consequently, the FSP‐OFET successfully emulates visual nervous responses to external light stimuli with ultralow energy consumption of 0.07–34 fJ per spike in short‐term plasticity and 0.41–19.87 fJ per spike in long‐term plasticity, both approaching the energy efficiency of biological synapses (1–100 fJ). Moreover, an artificial optic‐neural network made from an 8 × 8 FSP‐OFET array on a flexible substrate shows excellent image recognition and reinforcement abilities at a low energy cost. The designed FSP‐OFET offers an opportunity to realize photonic neuromorphic functionality with extremely low energy consumption dissipation.
Engineered Living Hydrogels
Authors: Liu Xinyue , Inda Maria Eugenia , Lai Yong , Lu Timothy K. , Zhao Xuanhe 
Published: March 2022

AbstractLiving biological systems, ranging from single cells to whole organisms, can sense, process information, and actuate in response to changing environmental conditions. Inspired by living biological systems, engineered living cells and nonliving matrices are brought together, which gives rise to the technology of engineered living materials. By designing the functionalities of living cells and the structures of nonliving matrices, engineered living materials can be created to detect variability in the surrounding environment and to adjust their functions accordingly, thereby enabling applications in health monitoring, disease treatment, and environmental remediation. Hydrogels, a class of soft, wet, and biocompatible materials, have been widely used as matrices for engineered living cells, leading to the nascent field of engineered living hydrogels. Here, the interactions between hydrogel matrices and engineered living cells are described, focusing on how hydrogels influence cell behaviors and how cells affect hydrogel properties. The interactions between engineered living hydrogels and their environments, and how these interactions enable versatile applications, are also discussed. Finally, current challenges facing the field of engineered living hydrogels for their applications in clinical and environmental settings are highlighted.
Phenotypic and molecular characterization of five patients with PIK3CA‐related overgrowth spectrum (PROS)
Authors: Gökpınar İli Ezgi , Taşdelen Elifcan , Durmaz Ceren Damla , Altıner Şule , Tuncalı Timur , Martinez‐Glez Victor , Karabulut Halil Gürhan , Vural Seçil , Ceylaner Serdar , Acar Mustafa Oğuz , Ilgın Ruhi Hatice 
Published: March 2022

AbstractSomatic and germline PI3K‐AKT‐mTOR pathway pathogenic variants are involved in several segmental overgrowth phenotypes such as the PIK3CA‐related overgrowth spectrum (PROS), Proteus syndrome, and PTEN hamartoma tumor syndrome. In this study, we describe five patients with PROS. We identified by high‐throughput sequencing four different somatic PIK3CA pathogenic variants in five individuals. The Glu726Lys variant, which was previously reported in megalencephaly‐capillary malformation‐polymicrogyria (MCAP) syndrome, was identified in two patients with unclassified PROS. The Cys420Arg substitution, which was previously reported in CLOVES, was found in a patient with fibroadipose hyperplasia. Additionally, relatively rare pathogenic variants, His1047Tyr and Tyr1021Cys, were detected in two patients with MCAP. Therefore, we suggest performing deep sequencing of PIK3CA in all patients with suspected PROS, instead of targeted polymerase chain reaction for hotspot pathogenic variants.
Activation of CO Using a 1,2‐Disilylene: Facile Synthesis of an Abnormal N‐Heterocyclic Silylene
Authors: Garg Palak , Carpentier Ambre , Douair Iskander , Dange Deepak , Jiang Yixiao , Yuvaraj K. , Maron Laurent , Jones Cameron 
Published: March 2022

AbstractReaction of the 1,2‐disilylene, [{ArC(NDip)2}Si]2 1 (Dip=2,6‐diisopropylphenyl, Ar=4‐C6H4But), with CO proceeds via insertion of CO into one Si−N bond, and Si−Si bond cleavage, to cleanly give the bis(silylene), {ArC(NDip)2}Si(:)O
Ar 2, under ambient conditions. The reaction can be partially reversed when solutions of 2 are subjected to UV irradiation. The five‐membered heterocyclic fragment of 2 represents the first silicon analogue of an “abnormal” N‐heterocyclic carbene (aNHC), a view which is substantiated by a computational analysis of the compound. Reaction of 2 with [Mo(CO)6] under UV light affords the chelate complex, [Mo(CO)4(κ2‐Si,Si‐2)] 3, while reaction with [Fe(CO)5] gives the unusual silyleneyl bridged complex, [{Fe2(CO)6}{μ‐Si[(NDip)2CAr]}2] 4. The same coordination complexes can be accessed by reaction of 1 with [Mo(CO)6] or [Fe(CO)5] under UV light. As is the case for aNHCs, d‐block metal complexes of bis(silylene) 2 could prove useful as bespoke catalysts for organic transformations.
Gold(I)‐Catalyzed Nucleophilic Allylation of Azinium Ions with Allylboronates
Authors: O'Brien Luke , Argent Stephen P. , Ermanis Kristaps , Lam Hon Wai 
Published: March 2022

AbstractGold(I)‐catalyzed nucleophilic allylations of pyridinium and quinolinium ions with various allyl pinacolboronates are reported. The reactions are completely selective with respect to the site of the azinium ion that is attacked, to give various functionalized 1,4‐dihydropyridines and 1,4‐dihydroquinolines. Evidence suggests that the reactions proceed through nucleophilic allylgold(I) intermediates formed by transmetalation from allylboronates. Density functional theory (DFT) calculations provided mechanistic insight.
Time‐of‐flight secondary ion mass spectrometric analysis of polymer surfaces: A review
Authors: Prasad Ananthu , Salim Nisa V. , Mozetič Miran , Kailas Lekshmi , Thomas Sabu 
Published: March 2022

AbstractTime of flight‐secondary ion mass spectrometry (ToF‐SIMS) is a SIMS based surface sensitive technique that provide specific compound identification of surface molecules. Recently, the importance of ToF‐SIMS has grown for the characterization and utilization of polymers, pharmaceuticals, semi‐conductors. The compound specificity of ToF‐SIMS distinguishes it from other surface characterization techniques such as X‐ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), and so forth, making it a preferred tool for the effective surface analysis of polymers. The purpose of this review is to elucidate the capability of ToF‐SIMS technique to effectively analyze the surface chemistry of polymer materials.
Disturbance observer‐based tracking control with prescribed performance specifications for a class of nonlinear systems subject to mismatched disturbances
Authors: Zhou Chengqian , Dai Chen , Yang Jun , Li Shihua 
Published: March 2022

AbstractThis work investigates simultaneous prescribed performance tracking control and mismatched disturbance rejection problems for a class of strict‐feedback nonlinear systems. A novel control scheme combining prescribed performance control, disturbance observer technique, and backstepping method is proposed. The disturbance estimations are introduced into the design of virtual control law design in each step to compensate the mismatched disturbances. To further improve the control performance, a prescribed performance function characterizing the error convergence rate, maximum overshoot, and steady‐state error is used to construct the composite controller. The proposed controller guarantees transient and steady‐state performance specifications of tracking error and provides much better disturbance attenuation ability simultaneously. Rigorous stability analysis for the closed‐loop system is established by direct Lyapunov function method. It is shown that all the states in the resulting closed‐loop system are stable, and the tracking error evolves within the prescribed performance boundaries and asymptotically converges to zero even in the presence of mismatched external disturbances. Finally, theoretical results are illustrated and demonstrated by two simulation examples.
Distributed second‐order multi‐agent constrained optimization algorithm with time‐varying cost function
Authors: Hu Haokun , Mo Lipo , Long Fei 
Published: March 2022

AbstractThis paper mainly discusses distributed constrained optimization problem for second‐order multi‐agent system under undirected communication network. The task of all agents is to minimize the sum of the local convex functions, where each agent is individual and only accesses to one objective function. Different from the most existing results, where the objective functions are assumed to be time‐invariable, this paper considers the situation of time‐varying objective function. Besides, we don't require that the Hessian matrices are identical and the gradients are bounded. First, a novel time‐varying optimization algorithm is proposed based on the projection algorithm. Second, by using convex analysis and Lyapunov theory, it is shown that the states of all agents can reach consensus and asymptotically converge to the neighborhood of the optimal solution. Finally, some numerical examples are given to verify the effectiveness of our algorithms.
Influence of different salts of alkali and alkaline earth metals on the pyrolysis of Prosopis juliflora
Authors: Saynik Philip Bernstein , Moholkar Vijayanand S. 
Published: March 2022

AbstractThis study explores the effect of acetate, oxide and chloride salts of alkali and alkaline earth metals (AAEMs) on the pyrolysis of lignocellulosic biomass. Prosopis juliflora samples were infused using 2% acetate and chloride salts of potassium (CH3COOK, KCl) and the oxide and chloride salts of magnesium (MgO, MgCl2). Dry impregnation technique was employed for the infusion of salts into the biomass matrix. The AAEM salt‐infused biomass was pyrolyzed using a semi‐batch pyrolysis reactor, and the bio‐oils were characterized for variation in chemical composition using gas chromatography–mass spectroscopy. The AAEM salts significantly influenced the pyrolysis process by catalyzing different degradation pathways. Potassium salts catalyzed the ring fission reactions of carbohydrates, resulting in an increase in carboxylic acid yield. On the other hand, magnesium salts promoted the cyclization of the fragmented radicals of the ring fission, resulting in enhanced furan and cycloketone yield. AAEM salts were most effective in catalyzing carbohydrate degradation pathways over the lignin degradation reactions owing to their ability to easily influence polysaccharide C–C bond cleavage over those of lignin aromatic rings. This study also revealed that the anions of AAEM salts also play a major role in biomass pyrolysis. © 2022 Society of Chemical Industry and John Wiley & Sons, Ltd
Multiple gene expression in plants using MIDAS‐P, a versatile type II restriction‐based modular expression vector
Authors: Pinneh Elizabeth C. , van Dolleweerd Craig J. , Göritzer Kathrin , Drake Pascal M. W. , Ma Julian K‐C. , Teh Audrey Y‐H. 
Published: March 2022

AbstractMIDAS‐P is a plant expression vector with blue/white screening for iterative cloning of multiple, tandemly arranged transcription units (TUs). We have used the MIDAS‐P system to investigate the expression of up to five genes encoding three anti‐HIV proteins and the reporter gene DsRed in Nicotiana benthamiana plants. The anti‐HIV cocktail was made up of a broadly neutralizing monoclonal antibody (VRC01), a lectin (Griffithsin), and a single‐chain camelid nanobody (J3‐VHH). Constructs containing different combinations of 3, 4, or 5 TUs encoding different components of the anti‐HIV cocktail were assembled. Messenger RNA (mRNA) levels of the genes of interest decreased beyond two TUs. Coexpression of the RNA silencing suppressor P19 dramatically increased the overall mRNA and protein expression levels of each component. The position of individual TUs in 3 TU constructs did not affect mRNA or protein expression levels. However, their expression dropped to non‐detectable levels in constructs with four or more TUs each containing the same promoter and terminator elements, with the exception of DsRed at the first or last position in 5 TU constructs. This drop was alleviated by co‐expression of P19. In short, the MIDAS‐P system is suitable for the simultaneous expression of multiple proteins in one construct.