bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fine Chemical Synthesis – Homogeneous
Authors: de Vries Johannes G. 
Published: December 2022

AbstractUse of homogeneous catalysis for fine chemical production is rapidly expanding. Advantages of its use are high chemo‐, regio‐, and enantioselectivity, which can be tuned by ligand design. Use of catalysis also leads to cleaner production processes. A third adavantage are the mild conditions that are often possible, which allows the application of homogeneous catalysis as a late step in a total synthesis. Often protective groups are unnecessary.While in the past homogeneous catalysis was mainly used for second‐generation processes of rather large products, it is now increasingly used in the first production processes. This is related to an increased availability of catalysts with sufficient rate and stability. In addition, high throughput experimentation allows rapid screening of these catalysts.While several hundred reactions are known that are catalyzed by homogeneous transition metal catalysts, only a limited number of these are applied for fine chemical production. They can be subdivided into four main classes: hydrogenation, carbon–carbon bond formation, carbon–heteroatom bond formation, and isomerization reactions. Important requirements are rate of the reaction, expressed as turnover frequency (TOF) and catalyst stability, expressed as turnover number (TON). Examples are given of many processes on scales varying from 1 to 10,000 ton/year.Recycle of catalysts is rarely practiced in fine chemical production, as the extra unit operations involved does not outweigh the gains of a reuse of the catalyst. Immobilization of homogeneous transition metal catalysts often leads to loss of activity and selectivity. In addition catalyst deactivation makes this an unattractive option. Emphasis is on the development of very fast catalysts. The metal is usually sent to the producer for reclaiming and refining. Two‐phase catalysis might be a viable option for catalyst recycle.Double digit growth is expected in the coming years for the application of homogeneous catalysis in the production of fine chemicals.
Heteropolyacids
Authors: Misono Makoto 
Published: December 2022

AbstractCatalytic properties of heteropoly compounds as well as their syntheses, structures, and fundamental chemical properties are described. The term heteropoly compounds are used here for heteropolyacids (HPAs) and their derivatives, and these are also called polyoxometalates and metal–oxygen clusters. Since the chemical properties such as acidic and redox properties can be controlled in a wide range by choosing the constituting elements of polyanions and the polyanion structures, these compounds are valuable materials for the design of practical catalysts and also fundamental studies of catalysis. As for the solid HPA catalysts, the hierarchical structure (primary, secondary, and tertiary structures) and the presence of three types of catalyses, (1) surface‐type, (2) bulk‐type (I) or pseudoliquid, and (3) bulk‐type (II)) catalysis, are important for understanding the catalysis of HPA and catalyst design based on HPA.There are already several industrial processes utilizing these compounds as catalysts for oxidation and acid‐catalyzed reactions both in liquid phase and in gas–solid phase. Most widely used HPAs are of Keggin‐type, e.g., H3PMo12O40and H3PW12O40. In addition, the promising future opportunities of HPA catalysts such as bifunctional catalysts like a combination of HPA with noble metal, hydrophobic HPA catalysts, shape‐selective HPA catalysts, and HPA having novel polyanion structures and compositions are described.
Hydrodenitrogenation – Homogeneous
Authors: Fish Richard H. , Bianchini Claudio 
Published: December 2022

AbstractThe industrial hydrodenitrogenation (HDN) process entails the removal of nitrogen from heteroaromatic nitrogen compounds in petroleum feedstocks under very high temperatures (400–600°C) and high pressures (200 bar) of hydrogen gas. In order to understand the various steps associated with this complicated HDN reaction, organometallic chemists have attempted to define each important reaction utilizing a homogeneous catalysis approach. Therefore, studies on the modeling of the HDN process, with an emphasis on the synthetic and mechanistic aspects of the homogeneous catalytic hydrogenation of model petroleum, heteroaromatic nitrogen compounds with organometallic complexes as catalysts, at low temperature and low pressures of hydrogen gas, will be reviewed in this article. A comparison of the regioselectivities under various hydrogenation conditions for these compounds will be discussed for a wide variety of transition‐metal complexes with regard to the role of substrate binding at the metal ion center. The polynuclear heteroaromatic nitrogen compounds appear to hydrogenate more readily, under similar reaction conditions, in comparison with model petroleum compounds with mononuclear ring systems, e.g., pyridine. The relative rates of hydrogenation of a variety of heteroaromatic nitrogen compounds as well as compounds that inhibit and enhance selective hydrogenation of the nitrogen‐containing ring will also be a focus of this review. A relatively new spectroscopic technique, high pressure nuclear magnetic resonance spectroscopy, will be shown to be a powerful tool to elucidate the mechanisms of the regioselective hydrogenation of polynuclear heteroaromatic nitrogen compounds. Finally, selected studies by other contributors to this nascent field will also be placed in perspective.
Hydrodesulfurization – Homogeneous
Authors: Sánchez‐Delgado Roberto A. 
Published: December 2022

AbstractIn spite of the large‐scale industrial applications of the hydrodesulfurization (HDS) process, and of the large number of studies of this reaction on heterogeneous catalysts, some aspects of the mechanisms involved are not yet fully understood. This article summarizes the most striking aspects of coordination and organometallic chemistry that are pertinent to the activation, hydrogenation, and desulfurization of thiophenes, in a systematic way, and inasmuch as possible in connection with the common knowledge and beliefs of the mechanisms of heterogeneous HDS catalysis. The binding of thiophenes to transition metals in molecular complexes, as well as the reactivity of such complexes in solution, is described in detail, with particular emphasis on reaction mechanisms. The examples presented are excellent molecular analogues of the species and reactions that are known or thought to intervene in heterogeneous catalysis, and thus this organometallic approach constitutes a good complement to surface and solid‐state chemistry studies and contributes to the understanding of this important reaction.
Magnesium Enzymes and Models
Authors: Cowan J. A. 
Published: December 2022

AbstractMost enzymes used in nucleic acid biochemistry, and many enzymes involved in general metabolism, require divalent magnesium as an essential activator. The selection of magnesium reflects the relatively high intracellular abundance of this ion, and its mechanism of action is tuned to the specific physicochemical properties that characterize its solution chemistry. In turn, this has required refinement of the protein environment to bind Mg2+efficiently, and in a manner that preserves its catalytic integrity. This review summarizes what is known concerning the role of divalent magnesium as a mediator of enzymatic activity, and discusses this role in the context of the unique chemical properties of this metal cofactor. Mechanistic models and approaches that have been developed to understand these biological reactions are summarized, and a comparison is made with the catalytic mechanism demonstrated by metal complex mimics of magnesium‐promoted reactions.
Micelles/Micellar Catalysis
Authors: Oehme Guenther 
Published: December 2022

AbstractThe contribution gives a survey of the aggregation of surfactants in aqueous and organic media and the reactivity control in such self‐organized systems. Several examples of micellar catalysis in aqueous surfactant assemblies are discussed for solvolytic reactions, oxidation reactions, reductions, carbon–carbon coupling reactions, and spontaneous unimolecular reactions. The influence of surfactant assemblies can be an alteration of the reaction rate (activity), the selectivity (chemo‐, regio‐, and stereoselectivity) of chemical and photophysical pathways, and of quantum efficiency and ionization potentials. Reverse micelles are formed by surfactants in organic solvents with a low content of water and are of interest in an entrapment of enzymes. Comparable are microemulsions as surfactant‐initiated multiphase systems with water as component. They are reaction media with a high variety of polarity and a relatively high mass capacity. Organized media have a practical importance for polymerization reactions because of the regularity of the hydrophobic interior. Artificial enzymes with amphiphilic properties were developed in analogy to natural membrane systems. A typical membrane‐mimetic adaption is also the use of surfactant aggregates as photochemical microreactors. New trends are mentioned to give developments of practical importance, e.g., reactions in immobilized amphiphiles, micellar phase‐transfer catalysis, and micellar autocatalysis.
Oxidative Carbonylation – Homogeneous
Authors: Temkin Oleg N. , Bruk Lev G. 
Published: December 2022

AbstractThe most interesting types of oxidative carbonylation reactions are considered. The catalytic systems, conditions, and activity characteristics for alkynes, alcohols, arenes, and alkanes as substrates are presented. The main types of mechanisms for oxidative carbonylation reactions are formulated and discussed.
Zinc Enzymes and Models
Authors: Bertini Ivano , Luchinat Claudio , Sola Marco 
Published: December 2022

Abstract

Zinc acts as catalytic metal center in a large variety of enzymes belonging to all functional classes. Basically, zinc functions as a Lewis acid center that polarizes and properly orients the substrate in the catalytic cleft of the enzyme, and confers to the site the structural and electronic properties competent for catalysis. In the zinc hydrolases, which are the most important class of zinc enzymes, the metal also assists the nucleophilic attack eventually exreted on the substrate by an active site group. Indeed, such a group is most often a Zn‐bound hydroxide. This article summarizes the main structural and mechanistic features of a number of zinc enzymes whose function has been elucidated in detail through structural (X‐ray) and spectroscopic (UV–vis and NMR) techniques. The latter were most often carried out on metal‐substituted species in which Zn
2+
was replaced with another metal possessing useful electronic and magnetic properties, most often Co
2+
. Particular focus has been put on the structure–function relationships in zinc‐containing peptidases and phosphatases, which carry out the hydrolysis of the CN and PO bond in peptides and phosphate esters, respectively. Moreover, the active site structure and catalytic mechanism of carbonic anhydrase, which is an important enzyme responsible for the reversible hydration of carbon dioxide, and of superoxide dismutase and alcohol dehydrogenase, which are redox enzymes of great physiological relevance, are also described. The contributions to the comprehension of enzyme function obtained from investigations of low molecular weight coordination compounds mimicking the active site features have been highlighted.
Thermoplastic Elastomers
Authors: Kalita Uddhab , Parameswaran Bhavya , Singha Nikhil K. 
Published: December 2022

AbstractThermoplastic elastomers (TPEs) are biphasic blends of soft amorphous matrix and hard crystalline/glassy domains in which the soft matrix is physically integrated with the help of the hard phase. They possess the physical properties of thermoset rubbers, such as flexibility, softness, and resilience, but they can be processed by plastic processing techniques unlike rubbers. They can be recycled since no external cross‐linking agents are required during processing. This article delineates different synthetic methods (existing as well as the newer methods), structure–property relationship, morphology, environmental issues, health aspects, and applications of various classes of thermoplastic elastomers. Some of the new‐generation thermoplastic elastomers such as acrylate, self‐healing, silicone‐based, fluorinated, ionic, and bio‐based TPEs have been explored in industrial applications due to their attractive properties such as high performance, lower as well as upper service temperature, and high‐temperature resistance. The circular economy and sustainability aspects of the TPEs are also discussed.
Computational Fluid Dynamics
Authors: Wehinger Gregor D. 
Published: December 2022

Abstract
Computational fluid dynamics (CFD) is considered as a powerful modeling tool in the chemical technology. It can be used to gain fundamental understanding and therefore complement experiments, carry out sensitivity studies, or design highly customized reactor equipment if coupled with Computer‐Aided Design (CAD) and additive manufacturing (3D printing). CFD models in chemical engineering are challenging, since most of the problems are multiscale, multiphase, and multiphysics in nature. This article presents the fundamentals of governing equations, mesh generation, and solving with the finite volume method as well as modeling approaches for special phenomena being relevant for chemical engineering, such as heat transfer, turbulence, chemically reacting flow, and multiphase flow. Finally, the recent progress of CFD models for stirred‐tank reactors, packed‐bed reactors, and fluidized‐bed reactors is discussed.
Accelerated Life Tests: Bayesian Models
Authors: Soyer Refik , Erkanli Alaattin , Merrick Jason R. 
Published: December 2022

AbstractIn this article, we consider Bayesian models for constant‐stress, step‐stress, and competing risks' accelerated life tests. We present extensions of these models and develop Markov chain Monte Carlo methods to make Bayesian inferences from these models. We illustrate how posterior predictive distributions can be obtained for use‐stress reliability analysis based on the accelerated life test data.
Heterometallic Ferrocenyl Complexes and Their Application in the Treatment of Cancer
Authors: Lord Rianne M. , Hofmann Benjamin J. , Stringer Tameryn 
Published: December 2022

AbstractFerrocene, a stable 18‐electron metallocene, has been readily modified to include other functionalities by reactions such as Friedel–Crafts and Mannich. While ferrocene and its derivatives have many applications, for example, as fuel additives and materials chemistry, they have been heavily researched in the past three decades for their medicinal applications; namely, tamoxifen, a well‐known breast cancer drug, has been modified with ferrocene (ferrocifen) to improve breast cancer selectivity, and chloroquine, an antimalarial drug, was modified with ferrocene to improve its activity in chloroquine‐resistant malarial strains. In these two molecules, ferrocene imparts a metal‐specific effect, enhancing the therapeutic potential of these complexes. Ferrocifen and ferroquine are currently in phase II clinical trials and preclinical evaluation, respectively. No other ferrocene‐containing complexes have reached clinical trial stages. One strategy that could fast‐track these complexes to an advanced stage is to develop heterometallic complexes, as they often exhibit enhanced pharmacological properties and have different biological targets compared to their homometallic/mononuclear counterparts. In this article, we have highlighted the area of heterometallic ferrocenyl complexes and their applications in the treatment of cancer and look at the most promising complexes to date.
Methone, Pieria
Authors: Boufalis Angelos 
Published: December 2022

Abstract

Methone was a city‐state in Pieria and according to the literary tradition the earliest Greek colony in the Northern Aegean. It controlled one of the best ports and evolved into one of the busiest industrial centers in the region. Although territorially surrounded by the Macedonian kingdom, it preserved its independence through most of the Archaic and Classical period until it was destroyed in 354
bce
by Philip II because of its long‐standing alliance with the Athenians.
Caesarea Mauretaniae
Authors: Leveau Philippe 
Published: December 2022

Abstract

The city of Cherchell occupies the site of ancient
Caesarea Mauretaniae
. A first settlement named Iol was founded in the fifth century
bce
by Phoenicians. King Micipsa made it his capital in the second century. In 25, the emperor reestablished it and placed it under the authority of Juba II, the son of the king of Numidia and of Cleopatra Selene, the daughter of Cleopatra and Mark Antony. The royal couple and their son Ptolemy designed their capital on the model of Alexandria. After the annexation of the kingdom in 40
ce
,
Caesarea
was the capital of the province of
Mauretania Caesariensis
. The town was sacked by Firmus in 371/372. It was the capital of Second Mauretania during the Byzantine period.
Juveniles and adults differ in their beliefs about cues to deception and strategies during a hypothetical police interview
Authors: Bettens Talley , Warren Amye R. 
Published: December 2022

AbstractPolice officers are often trained to use the Behavior Analysis Interview (BAI) to detect deceit, but it is based on faulty indicators of lying that may be especially problematic for juveniles due to developmental immaturities. Juveniles, young adults, and adults were assigned to guilt or innocence conditions, read a criminal scenario, and self‐reported their likelihood of providing truthful and deceitful responses during a hypothetical BAI. All participants indicated they would give more truthful than deceptive responses. Guilty participants reported more use of strategies to appear innocent, while innocent participants said they would behave naturally. Juveniles were more likely to choose deceitful responses and say they would use strategies to appear innocent during a police interview but endorsed fewer stereotypical cues of deception compared to adults. Juveniles may not recognize how certain behaviors could be seen as cues to deception, which could put them at risk of being misidentified as guilty.
Adaptive fuzzy control for high‐order nonlinear systems with time‐varying full‐state constraints and input saturation
Authors: Liu Jianqin , Jiang Yan 
Published: December 2022

SummaryThe adaptive control for a class of high‐order nonlinear systems with time‐varying full‐state constraints and input saturation is investigated in this paper. To deal with time‐varying constraints, a type of high‐order barrier Lyapunov functions(BLFs) are constructed. Its performance can be guaranteed with the disappearance of constraints. By building fuzzy systems, unknown functions can be approximated. Together with adding a power integrator technique and the gain‐update law, an adaptive controller is designed. As a result, all the constraints are not breached, and the tracking error converges to an arbitrarily small zone around the origin. Finally, a practical example and a numerical example illustrate the effectiveness of the proposed method.
Nitric Oxide Generation and Endothelial Progenitor Cells Recruitment for Improving Hemocompatibility and Accelerating Endothelialization of Tissue Engineering Heart Valve
Authors: Zhou Ying , Yan Ge , Wen Shuyu , Yim Wai Yen , Wang Zihao , Chen Xing , Xu Yin , Chen Xue , Cao Hong , Bai Peng , Li Fei , Shi Jiawei , Wang Jianglin , Qiao Weihua , Dong Nianguo 
Published: December 2022

AbstractTissue engineering heart valve (TEHV) offers great potential to overcome the limitations of commercial artificial valves used in clinical practice as a permanent prosthetic valve. Currently, decellularized heart valve (DHV) is the most widely used scaffold for TEHV, but showed suboptimal performance due to difficulty of endothelialization. Facilitating endothelialization of DHV is indispensable for better valve performance, and excellent hemocompatibility guarantees enough time windows for endothelialization process. Herein, a dual‐functional TEHV scaffold with improving hemocompatibility and accelerating endothelialization is constructed by modifying DHV with copper ions (Cu) and growth differentiation factor 11 (GDF11). Results show the newly‐constructed scaffold successfully generates endogenous nitric oxide (NO) through catalysis of Cu, and possesses improved hemocompatibility by down‐regulating platelets activation and adhesion. Furthermore, GDF11 immobilization significantly accelerates scaffold endothelialization through facilitating recruitment, supporting growth, and alleviating apoptosis of endothelial progenitor cells . This TEHV scaffold shows favorable performance under in vivo hemodynamic environment with intact endothelial coverage and adaptive ECM remodeling, and without thrombus or calcification formation. This newly‐constructed TEHV scaffold is expected to make up for the shortcomings of currently available prosthetic valves in clinical practice and has the potential possibility of rapid translation to the clinic as a better prosthetic valve.
Intracellular Glucose‐Depriving Polymer Micelles for Antiglycolytic Cancer Treatment
Authors: Lee Jangwook , Kim Kwangmeyung , Kwon Ick Chan , Lee Kuen Yong 
Published: December 2022

AbstractA new anticancer strategy to exploit abnormal metabolism of cancer cells rather than to merely control the drug release or rearrange the tumor microenvironment is reported. An antiglycolytic amphiphilic polymer, designed considering the unique metabolism of cancer cells (Warburg effect) and aimed at the regulation of glucose metabolism, is synthesized through chemical conjugation between glycol chitosan (GC) and phenylboronic acid (PBA). GC‐PBA derivatives form stable micellar structures under physiological conditions and respond to changes in glucose concentration. Once the micelles accumulate at the tumor site, intracellular glucose capture occurs, and the resultant energy deprivation through the inhibition of aerobic glycolysis remarkably suppresses tumor growth without significant side effects in vivo. This strategy highlights the need to develop safe and effective cancer treatment without the use of conventional anticancer drugs.
A lightweight semantic‐enhanced interactive network for efficient short‐text matching
Authors: Yu Chuanming , Xue Haodong , An Lu , Li Gang 
Published: December 2022

AbstractKnowledge‐enhanced short‐text matching has been a significant task attracting much attention in recent years. However, the existing approaches cannot effectively balance effect and efficiency. Effective models usually consist of complex network structures leading to slow inference speed and the difficulties of applications in actual practice. In addition, most knowledge‐enhanced models try to link the mentions in the text to the entities of the knowledge graphs—the difficulties of entity linking decrease the generalizability among different datasets. To address these problems, we propose a lightweight Semantic‐Enhanced Interactive Network (SEIN) model for efficient short‐text matching. Unlike most current research, SEIN employs an unsupervised method to select WordNet's most appropriate paraphrase description as the external semantic knowledge. It focuses on integrating semantic information and interactive information of text while simplifying the structure of other modules. We conduct intensive experiments on four real‐world datasets, that is, Quora, Twitter‐URL, SciTail, and SICK‐E. Compared with state‐of‐the‐art methods, SEIN achieves the best performance on most datasets. The experimental results proved that introducing external knowledge could effectively improve the performance of the short‐text matching models. The research sheds light on the role of lightweight models in leveraging external knowledge to improve the effect of short‐text matching.