bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multistage nonlinear model predictive control for pumping treatment in hydraulic fracturing
Authors: Lin Kuan‐Han , Eason John P. , Biegler Lorenz T. 
Published: December 2021

AbstractHydraulic fracturing has gained increasing attention as it allows the constrained natural gas and crude oil to flow out of low‐permeability shale formations and significantly increase production. Perilous operating states of extremely high pressure also raise some safety concerns, requiring us to formulate an appropriate dynamic model, and provide a careful engineering control to ensure safe operating conditions. Moreover, uncertainties due to spatially varying rock properties increase the difficulties in control of the fracturing process. In this work, we formulate a first‐principles model by considering the fracture evolution, mass transport of substances in the slurry, changing fluid properties, and the monitored operating pressure on the ground level. Next, we implement nonlinear model predictive control (NMPC) to control the process under a set of final requirements and process constraints. Our results show that the performance of standard NMPC degrades when the rock uncertainty causes the parameter mismatch between the process and the predictive model in the controller. With standard NMPC, designed with a nominal model, the process fails to meet the terminal requirements of fracture geometry, and pressure is violated in one of the parameter mismatch cases. Therefore, we resort to multistage NMPC, which considers uncertainty evolution in a scenario tree with separate control sequences to address constraint violations. We demonstrate that multistage NMPC presents good performance by showing constraint satisfaction whether the uncertain rock parameter realization is time‐invariant or time‐variant. We also simulate the process with multistage NMPC including different numbers of scenarios and compare their control performance. Our investigation demonstrates that multistage NMPC effectively manages parametric uncertainties attributed to non‐homogeneous rock formation, and provides a promising control strategy for the hydraulic fracturing process.
A generalized reduced fluid dynamic model for flow fields and electrodes in redox flow batteries
Authors: Cheng Ziqiang , Tenny Kevin M. , Pizzolato Alberto , Forner‐Cuenca Antoni , Verda Vittorio , Chiang Yet‐Ming , Brushett Fikile R. , Behrou Reza 
Published: December 2021

AbstractHigh‐dimensional models typically require a large computational overhead for multiphysics applications, which hamper their use for broad‐sweeping domain interrogation. Herein, we develop a modeling framework to capture the through‐plane fluid dynamic response of electrodes and flow fields in a redox flow cell, generating a computationally inexpensive two‐dimensional (2D) model. We leverage a depth‐averaging approach that also accounts for variations in out‐of‐plane fluid motion and departures from Darcy's law that arise from averaging across three‐dimensions (3D). Our resulting depth‐averaged 2D model successfully predicts the fluid dynamic response of arbitrary in‐plane flow field geometries, with discrepancies of <5% for both maximum velocity and pressure drop. This corresponds to reduced computational expense, as compared to 3D representations (<1% of duration and 10% of RAM usage), providing a platform to screen and optimize a diverse set of cell geometries.
Palladium‐Catalyzed Selective Hydroamination of Aliphatic Alkenes with Hydrazides
Authors: Xia Lanlan , Wu Yundan , Lin Cong , Gao Fei , Shen Liang 
Published: December 2021

AbstractThe first facile and efficient palladium‐catalyzed selective hydroamination of aliphatic alkenes with hydrazides as nitrogen‐based reaction partners has been described. This method provides a divergent and regioselective access to a variety of γ‐ and δ‐hydrazide substituted amide derivatives. The 8‐aminoquinolyl directing group could be readily removed to afford the corresponding γ‐ and δ‐hydrazide substituted carboxylic acid derivatives that are commonly seen in drug molecules and other bioactive compounds.
Spinal Cord Atrophy Predicts Progressive Disease in Relapsing Multiple Sclerosis
Authors: Bischof Antje , Papinutto Nico , Keshavan Anisha , Rajesh Anand , Kirkish Gina , Zhang Xinheng , Mallott Jacob M. , Asteggiano Carlo , Sacco Simone , Gundel Tristan J. , Zhao Chao , Stern William A. , Caverzasi Eduardo , Zhou Yifan , Gomez Refujia , Ragan Nicholas R. , Santaniello Adam , Zhu Alyssa H. , Juwono Jeremy , Bevan Carolyn J. , Bove Riley M. , Crabtree Elizabeth , Gelfand Jeffrey M. , Goodin Douglas S. , Graves Jennifer S. , Green Ari J. , Oksenberg Jorge R. , Waubant Emmanuelle , Wilson Michael R. , Zamvil Scott S. ,   University of California, San Francisco MS‐EPIC Team, Cree Bruce A. C. , Hauser Stephen L. , Henry Roland G. 
Published: December 2021

ObjectiveA major challenge in multiple sclerosis (MS) research is the understanding of silent progression and Progressive MS. Using a novel method to accurately capture upper cervical cord area from legacy brain MRI scans we aimed to study the role of spinal cord and brain atrophy for silent progression and conversion to secondary progressive disease (SPMS).MethodsFrom a single‐center observational study, all RRMS (n = 360) and SPMS (n = 47) patients and 80 matched controls were evaluated. RRMS patient subsets who converted to SPMS (n = 54) or silently progressed (n = 159), respectively, during the 12‐year observation period were compared to clinically matched RRMS patients remaining RRMS (n = 54) or stable (n = 147), respectively. From brain MRI, we assessed the value of brain and spinal cord measures to predict silent progression and SPMS conversion.ResultsPatients who developed SPMS showed faster cord atrophy rates (−2.19%/yr) at least 4 years before conversion compared to their RRMS matches (−0.88%/yr, p < 0.001). Spinal cord atrophy rates decelerated after conversion (−1.63%/yr, p = 0.010) towards those of SPMS patients from study entry (−1.04%). Each 1% faster spinal cord atrophy rate was associated with 69% (p < 0.0001) and 53% (p < 0.0001) shorter time to silent progression and SPMS conversion, respectively.InterpretationSilent progression and conversion to secondary progressive disease are predominantly related to cervical cord atrophy. This atrophy is often present from the earliest disease stages and predicts the speed of silent progression and conversion to Progressive MS. Diagnosis of SPMS is rather a late recognition of this neurodegenerative process than a distinct disease phase. ANN NEUROL 2022;91:268–281
Cathespin B‐Initiated Cypate Nanoparticle Formation for Tumor Photoacoustic Imaging
Authors: Wang Chenchen , Du Wei , Wu Chenfan , Dan Shan , Sun Miao , Zhang Tong , Wang Bin , Yuan Yue , Liang Gaolin 
Published: December 2021

AbstractCathepsin B (CTSB) is a lysosomal protease that is overexpressed in the early stage of many cancer types. Precise evaluation of CTSB expression in vivo may provide a promising method for the early diagnosis of cancers. By virtue of the high‐resolution PA imaging modality, a “smart” photoacoustic (PA) probe Cypate‐CBT, which can self‐assemble to cypate‐containing nanoparticles in response to abundant GSH and CTSB inside tumor cells, was developed for the sensitive and specific detection of CTSB activity. Compared with unmodified Cypate, our probe Cypate‐CBT exhibited a 4.9‐fold or 4.7‐fold PA signal enhancement in CTSB‐overexpressing MDA‐MB‐231 cancer cells or tumors, respectively, revealing intracellular accumulation of the probe after CTSB‐initiated self‐assembly. We expect Cypate‐CBT to be employed as an effective PA imaging agent for clinical diagnosis of cancer at early stages.
Electrochemical Desaturative β‐Acylation of Cyclic N‐Aryl Amines
Authors: Feng Tian , Wang Siyi , Liu Yin , Liu Shouzhuo , Qiu Youai 
Published: December 2021

AbstractHerein, we disclose a straightforward, robust, and simple route to access β‐substituted desaturated cyclic amines via an electrochemically driven desaturative β‐functionalization of cyclic amines. This transformation is based on multiple single‐electron oxidation processes using catalytic amounts of ferrocene. The reaction proceeds in the absence of stoichiometric amounts of electrolyte under mild conditions, affording the desired products with high chemo‐ and regioselectivity. The reaction was tolerant of a broad range of substrates and also enables late‐stage β‐C(sp3)−H acylation of potentially valuable products. Preliminary mechanistic studies using cyclic voltammetry reveal the key role of ferrocene as a redox mediator in the reaction.
Flame retardancy of polyurethane foams prepared from green polyols with flame retardants
Authors: Lee Pyung Soo , Jung Simon MoonGeun 
Published: December 2021

AbstractPolyurethane foams (PUFs) were synthesized using bis(2‐hydroxyethylene terephthalate) (BHET), 1,4‐cyclohexanedimethanol (CHDM), and polycaprolactone diol (PCLD), and their flame retardancies were investigated. BHET and CHDM are eco‐friendly chemicals derived from waste polyethylene terephthalate, and PCLD is a precursor monomer used for synthesizing biodegradable polymers. Expandable graphite (EG) and tris(1‐chloro‐2‐isopropyl) phosphate (TCPP) were used as flame retardants. For conventional PUFs prepared with an aliphatic polyol, thermal stability was significantly enhanced with EG and TCPP through thermogravimetric analysis (TGA) and micro‐combustion calorimetry (MCC). PUFs prepared with BHET and CHDM exhibited higher thermal stability than conventional PUFs. This is attributed to the alicyclic and aromatic ring structures, which contribute to thermally stable char formation during pyrolysis. PCLD was introduced as an additional polyol, as well as a possible flame retardant, without the addition of EG and TCPP. PUFs were successfully prepared and exhibited improved resilience to burning up to 300°C due to the intrinsic thermal stability of PCLD. The limiting oxygen index (LOI) indicated that PUFs containing BHET moiety exhibited higher LOI values, whereas PUFs prepared with PCLD showed the lowest LOI value. PCLD can be used as a polyol; however, additional flame retardants are needed to obtain high flame retardancy for PUFs.
Preparation and characterization of citric acid crosslinked chitosan‐cellulose nanofibrils composite films for packaging applications
Authors: Ponnusamy Prabaharan Graceraj , Sundaram Jaya , Mani Sudhagar 
Published: December 2021

AbstractThe inferior water vapor permeability and water resistance properties are the major challenges that hindered the development of chitosan‐CNF composites for packaging applications. In this study, the chitosan‐CNF composite films were prepared with in situ crosslinking of citric acid (CA) to reduce the percent water uptake (WU) and water vapor permeability (WVP). The composite films were produced by the solvent casting method with 10%, 15%, and 20% CNF as a reinforcement, 20%, 25%, and 30% CA as a crosslinker, and 20% glycerol as a plasticizer. The Fourier transform infrared (FTIR) spectra of composite films with a peak at 1710 cm−1 confirmed the effective crosslinking of citric acid on the chitosan‐CNF matrix. The crosslinked composite films exhibited the lowest WU of 39% and WVP of 9.99 × 10−7 g/Pa s m2 with reduced light transmittance due to CNF reinforcement. The scanning electron microscopy (SEM) study showed the smooth surface morphology of composite films. The CA crosslinking slightly decreased the tensile strength of composite films. However, the composite film with optimal CNF and CA concentration (25% and 20%, respectively) exhibited comparable tensile strength with other synthetic and biopolymer composites and can be used as a potential biopolymer composite for packaging applications.
Finteching remittances in paradise: A path to sustainable development
Authors: Hahm Hongjoo , Subhanij Tientip , Almeida Rui 
Published: December 2021

AbstractThe costs of sending remittances to Pacific small island developing states (SIDS) are among the highest in the world. Tackling this issue is crucial not only for economic and social development, but also for improving financial inclusion. This article analyses fintech adoption in remittance services, namely the adoption of alternative payment methods in transferring money by using the internet or mobile phones, in the Pacific. It introduces an original framework to assess the current landscape of fintech in the remittance sector and draws tailored policy recommendations. The framework is conceptualised through a ladder with five rungs: availability, accessibility, awareness, literacy and trust. Based on the ladder analysis, the authors observe the lack of basic digital infrastructure and digital platforms in many Pacific SIDS. Where the technological landscape is better developed, fintech services have established strong footholds, but there is a need for greater awareness to broaden its appeal and customer base. The benefits of fintech platforms are high, especially in the context of lower remittance costs which constitute an unduly large share of GDP in Pacific SIDS. The basic infrastructure needed to develop fintech services are equally important for the overall sustainable development of Pacific SIDS. The article observes fintech services in the Pacific are a means for financial inclusion of the unbanked, that can accelerate the economic and social development of the SIDS, and countries in the Pacific region are at different stages in their readiness for fintech adoption.
Haemolymph metabolomic differences in silkworms (Bombyx mori L.) under mulberry leaf and two artificial diet rearing methods
Authors: Tao Shanshan , Wang Jie , Liu Minghui , Sun Fan , Li Bing , Ye Chongjun 
Published: December 2021

AbstractThe new technology of silkworm (Bombyx mori L.) artificial feed breeding has many characteristics and advantages. This study assessed silkworm rearing with mulberry leaf at all instars (MF) as the control, and used metabolomics to explore the differences in haemolymph metabolism of fifth instar silkworms under two modes of rearing with an artificial diet at all instars (AF) and rearing with an artificial diet during first to third instars and mulberry leaf during the fourth and fifth instars (AMF). The results show that, compared with silkworms of the MF group, the amount and fold change of various metabolites were higher in the haemolymph of AF group silkworms, and the metabolism of amino acids and uric acid, carbohydrates, lipids, and vitamins were changed. These changes may be the reasons for the poor performance of the AF silkworms. However, the amount and fold change of the various metabolites of silkworms in the AMF group were lower, and some metabolic pathways were more active. The amount of material and energy supply were greater. These changes could explain the high efficiency growth of body weight of silkworms after the conversion from artificial diet rearing to mulberry leaf rearing. These findings provide an important theoretical basis for the optimisation of artificial diet rearing technology for silkworms.
A chalcone‐based fluorescent chemosensor for detecting Mg2+ and Cd2+
Authors: Park Soyoung , Suh Boeon , Kim Cheal 
Published: December 2021

AbstractSBOD (sodium (E)‐2‐(3‐[5‐bromothiophen‐2‐yl]‐3‐oxoprop‐1‐en‐1‐yl)‐4,6‐dichlorophenolate) was designed and synthesized as a chalcone‐based fluorescent turn‐on chemosensor for Mg2+ and Cd2+. SBOD selectively detected Mg2+ and Cd2+ through the increase in effective fluorescence. Detection limits of SBOD for Mg2+ and Cd2+ were calculated to be 3.8 μM and 2.9 μM, respectively. The binding modes of SBOD for Mg2+ and Cd2+ were determined to be 1:1 by ESI‐MS and Job plot. Association mechanisms for SBOD to Mg2+ and Cd2+ were illustrated by ESI‐MS, UV–vis, fluorescence spectroscopy, and calculations.
Prediction of human cytochromeP450inhibition using bio‐selectivity induced deep neural network
Authors: Park Hyejin , Brahma Rahul , Shin Jae‐Min , Cho Kwang‐Hwi 
Published: December 2021

AbstractSince the successful debut of AlphaGo, deep learning (DL) techniques have been applied to almost all areas of data sciences and are achieving remarkable milestones. For example, in predicting cytochrome P450 (CYP450) inhibition, DL and other machine learning techniques applied were proven significantly useful. However, currently, most models are focused on how much they can improve compared to previously published methods by using different methodologies and larger data sets without considering bio‐selectivity. This study provides a multitask classification model for five important isoforms of CYP450. Our model uses the most extensive data set of over 150 000 molecules ever used. To consider the stereoisomerism of bio‐selectivity, new descriptors have been developed. We illustrated the discriminating power of the new descriptors with some examples that demonstrated the improvement in the model's performance using three‐dimensional descriptors, which account for the stereoselectivity of drug–protein/enzymes that two‐dimensional models cannot achieve.
Synthesis of catechol‐conjugated chitosan and its application as an additive for cement mortar
Authors: Choi Hoe Young , Bae Sung‐Ho , Choi Se‐Jin , Ko Haye Min 
Published: December 2021

AbstractWe synthesized catechol‐conjugated chitosan (CCC) to study its usefulness as a construction material additive in cement mortar. The degree of catechol conjugation (DOCcat) of the synthesized CCC was determined to be approximately 14% by UV–vis and 1H NMR spectroscopy. Furthermore, the hydroxyl and amine groups in CCC could play a crucial role in hydrogen bonding, metal coordination, and cross‐linking processes via interaction with adducts from cement mortar. In this study, we observed an improvement in the compressive strength and absorption rate, suggesting that CCC is a promising candidate for high‐performance cement mortar.
Utilisation of CO2 as “Structure Modifier” of Inorganic Solids
Authors: Bennett M. J. , Dobson I. , Benoit D. M. , Francesconi M. G. 
Published: December 2021

AbstractUtilisation of CO2 as a chemical reagent is challenging, due to the molecule's inherent chemical stability. However, CO2 reacts promptly at high temperature (∼1000 °C) with alkaline‐earth oxides to form carbonates and such reactions are used towards capture and re‐utilisation. In this work, this concept is extended and CO2 is utilised as a reagent to modify the crystal structure of mixed‐metal inorganic solids. Modification of the crystal structure is a “tool” used by materials scientists to tailor the physical property of solids. CO2 gas was reacted with several isostructural mixed‐metal oxides Sr2CuO3, Sr1.8Ba0.2CuO3 and Ba2PdO3. These oxides are carefully selected to show anion vacancies in their crystal structure, to act as host sites for CO2 molecules, leading to the formation of carbonate anions, (CO3)2−. The corresponding oxide carbonates were formed successfully and the favourable formation of SrCO3 as secondary phase was minimised via an innovative, yet simple synthetic procedure involving alternating of CO2 and air. We also derived a simple model to predict the kinetics of the reactions for the cuprates, using first‐principles density functional theory and assimilating the reaction to a gas‐surface process.
Alkaline Stability of Low Oxophilicity Metallopolymer Anion‐Exchange Membranes
Authors: Aggarwal Kanika , Bsoul Saja , Douglin John C. , Li Songlin , Dekel Dario R. , Diesendruck Charles E. 
Published: December 2021

AbstractAnion‐exchange membrane fuel cells (AEMFCs) are promising energy conversion devices due to their high efficiency. Nonetheless, AEMFC operation time is currently limited by the low chemical stability of their polymeric anion‐exchange membranes. In recent years, metallopolymers, where the metal centers assume the ion transport function, have been proposed as a chemically stable alternative. Here we present a systematic study using a polymer backbone with side‐chain N‐heterocyclic carbene (NHC) ligands complexed to various metals with low oxophilicity, such as copper, zinc, nickel, and gold. The golden metallopolymer, using the metal with the lowest oxophilicity, demonstrates exceptional alkaline stability, far superior to state‐of‐the‐art quaternary ammonium cations, as well as good in situ AEMFC results. These results demonstrate that judiciously designed metallopolymers may be superior to purely organic membranes and provides a scientific base for further developments in the field.
Promoter‐Driven Overexpression in Chromobacterium vaccinii Facilitates Access to FR900359 and Yields Novel Low Abundance Analogs
Authors: Pistorius Dominik , Buntin Kathrin , Weber Eric , Richard Etienne , Bouquet Caroline , Wollbrett Séverine , Regenass Hugo , Peón Victor , Böhm Marcel , Kessler Régis , Gempeler Thomas , Haberkorn Anne , Wimmer Laurin , Lanshoeft Christian , Davis John , Hainzl Dominik , D'Alessio Joseph Anthony , Manchado Eusebio , Petersen Frank 
Published: December 2021

AbstractAccess to the cyclic depsipeptide FR900359 (FR), a selective Gq/11 protein inhibitor of high pharmacological interest and a potential lead molecule for targeted therapy of cancers with oncogenic GNAQ or GNA11 mutations (encoding Gq and G11 respectively), has been challenging ever since its initial discovery more than three decades ago. The recent discovery of Chromobacterium vaccinii as a cultivable FR producer enables the development of approaches leading to a high‐yielding, scalable and sustainable biotechnological process for production of FR, thereby removing this bottleneck. Here we characterize different promoters in exchange of the native promoter of the FR assembly line, resulting in an overexpression mutant with significantly increased production of FR. Thereby, the isolation and structure elucidation of novel FR analogs of low abundance is enabled. Further, we explore the antiproliferative activities of fifteen chromodepsins against uveal melanoma cell lines harboring Gq/11 mutations and characterize the major metabolite of FR formed in plasma.
BBr3‐Mediated P(III)‐Directed C−H Borylation of Phosphines
Authors: Lv Jiahang , Zhang Xue‐Jun , Wang Minyan , Zhao Yue , Shi Zhuangzhi 
Published: December 2021

AbstractTransition‐metal‐catalyzed C−H borylation has been widely used in the preparation of organoboron compounds. Here, we developed a general protocol on metal‐free P(III)‐directed C−H borylation of phosphines mediated by BBr3, resulting in the formation of products bearing both phosphorus and boron. The development of the metal‐free strategy to mimic previous metallic processes has shown low cost, superior practicality, and environmental friendliness. Density functional theory (DFT) calculations demonstrate the preferred pathway for this metal‐free directed C−H borylation process.
Rhodium and Iridium Complexes of Anionic Thione and Selone Ligands Derived from Anionic N‐Heterocyclic Carbenes
Authors: Ho Luong Phong , Neitzel Angelika , Bannenberg Thomas , Tamm Matthias 
Published: December 2021

AbstractThe lithium salts of anionic N‐heterocyclic thiones and selones [{(WCA‐IDipp)E}Li(toluene)] (1: E=S; 2: E=Se; WCA=B(C6F5)3, IDipp=1,3‐bis(2,6‐diisopropylphenyl)imidazolin‐2‐ylidene), which contain a weakly coordinating anionic (WCA) borate moiety in the imidazole backbone were reacted with Me3SiCl, to furnish the silylated adducts (WCA‐IDipp)ESiMe3 (3: E=S; 4: E=Se). The reaction of the latter with [(η5‐C5Me5)MCl2]2 (M=Rh, Ir) afforded the rhodium(III) and iridium(III) half‐sandwich complexes [{(WCA‐IDipp)E}MCl(η5‐C5Me5)] (5–8). The direct reaction of the lithium salts 1 and 2 with a half or a full equivalent of [M(COD)Cl]2 (M=Rh, Ir) afforded the monometallic complexes [{(WCA‐IDipp)E}M(COD)] (9–12) or the bimetallic complexes [μ2‐{(WCA‐IDipp)E}M2(COD)2(μ2‐Cl)] (13–16), respectively. The bonding situation in these complexes has been investigated by means of density functional theory (DFT) calculations, revealing thiolate or selenolate ligand character with negligible metal‐chalcogen π‐interaction.