bluuebunny/crossref_metadata_2025_split huggingface dataset:
Integrated thermodynamic and kinetic model of homogeneous catalytic N‐oxidation processes
Authors: Wang Jingyao , Mannan M. Sam , Wilhite Benjamin A. 
Published: November 2019

AbstractThe homogeneous phosphotungstic acid catalyzed N‐oxidation of alkylpyridines by hydrogen peroxide has important applications in pharmaceutical and fine chemical industries. Current industry practice is to employ a semibatch reactor with gradual dosing of hydrogen peroxide into an alkylpyridine/catalyst solution under isothermal conditions. However, due to lack of understanding of reaction mechanism and thermodynamic behavior, this system is subject to significant risk of flammability, fires and explosions due to hydrogen peroxide decomposition. In this study, we conducted semibatch N‐oxidation process in an isothermal reaction calorimeter (RC1) over a wide range of temperature, catalyst amount and oxidizer dosing rates. Reactor pressure, reaction heat generation rate and in situ FTIR spectra of liquid phase species were recorded in real‐time during experiments, and final product was quantified using HPLC and GC–MS analytical tools. We developed an integrated thermodynamic and kinetics model of homogeneous N‐oxidation reaction based on experimental results and past literature findings. More specifically, Wilson excess Gibbs model was employed to estimate activity coefficients of highly nonideal liquid mixture. We found ideal gas law was satisfactory in calculating incondensable oxygen pressure. First principle reaction mechanism and kinetics parameters of (a) catalytic N‐oxidation reaction; (b) catalytic hydrogen peroxide decomposition reaction; (c) noncatalytic N‐oxidation reaction; (d) noncatalytic hydrogen peroxide decomposition reaction was derived based on experimental findings of this study and past literature. The proposed integrated thermodynamic model and kinetics model successfully predicted highly nonlinear reactor pressure, species concentration and reaction enthalpy generation rate profile of homogenous catalytic N‐oxidation and H2O2 decomposition reaction. The optimal reactions conditions with maximum N‐oxide product yield and minimum reactor pressure and catalyst usage was theoretically identified and further verified by experiments. The obtained model can be used for inherently safer reactor design and applied to other homogeneous tungstic acid catalytic hydrogen peroxide oxidation processes.
Iridium‐katalysierte Hydrochlorierung und Hydrobromierung von Alkinen durch Shuttlekatalyse
Authors: Yu Peng , Bismuto Alessandro , Morandi Bill 
Published: November 2019

AbstractHier beschreiben wir zwei verschiedene Methoden zur Synthese von Vinylhalogeniden über eine Shuttlekatalyse‐basierte Iridium‐katalysierte Transfer‐Hydrohalogenierung nichtaktivierter Alkine. Die Verwendung von 4‐Chlorbutan‐2‐on oder tert‐Butylhalogenid als Donoren von Halogenwasserstoffen hat es ermöglicht, diese Umwandlung in Abwesenheit korrosiver Reagenzien wie Halogenwasserstoff oder Säurechloriden durchzuführen. Daher verbessern diese Reaktionen die Toleranz gegenüber funktionellen Gruppen sowie Sicherheitsaspekte verglichen zum aktuellen Stand der Forschung. Dies hat den Zugang zu Alkenylhalogenidverbindungen mit säureempfindlichen Gruppen wie tertiären Alkoholen, Silylethern und Acetalen ermöglicht. Der synthetische Wert dieser Methoden wurde durch eine Synthese im Gramm‐Maßstab, die mit einer geringen Katalysatorbeladung durchgeführt werden konnte, gezeigt.
Zusammenwirken von Rutheniumkatalysatoren und elektrokatalytisch generierten, hypervalenten Iodreagenzien für die C‐H‐Oxygenierung
Authors: Massignan Leonardo , Tan Xuefeng , Meyer Tjark H. , Kuniyil Rositha , Messinis Antonis M. , Ackermann Lutz 
Published: November 2019

AbstractDie katalytische Generierung von hypervalenten Iod(III)‐Reagenzien mittels anodischer Oxidation wurde genutzt, um bisher unbekannte elektrokatalytische C‐H‐Oxygenierungen an schwach koordinierenden aromatischen Amiden und Ketonen durchzuführen. Dabei ermöglichte die Kombination aus katalytischen Mengen an Iodarenen und Rutheniumkatalysatoren den raschen Zugang zu vielseitigen C‐H‐Aktivierungen an unterschiedlichen Substraten bei hoher Verträglichkeit mit unterschiedlichen funktionellen Gruppen. Umfassende mechanistische Studien belegen die bedeutende Rolle der Iodarene als elektrochemisch relevante Spezies für die C‐H‐Oxygenierung mit Strom als nachhaltigem Oxidationsmittel und molekularem Wasserstoff als einzigem Nebenprodukt. Zudem konnten para‐selektive C‐H‐Oxygenierungen ohne dirigierende Gruppen durchgeführt werden.
Advance on processing of compostable and thermally stable biodegradable polyester blends
Authors: Barletta Massimiliano , Aversa C. , Pizzi E. , Puopolo M. 
Published: November 2019

ABSTRACTFlexible and semiflexible packagings can be manufactured by cast extrusion of plastic sheet and thermoforming of containers. Thermal stability is often required as packaging items after being thermoformed can come in contact with hot food/beverage, especially during hot filling operations. In this framework, the present study deals with the design and manufacturing by thermoforming of plastic containers that are, at the same time, compostable and suitable for high‐temperature applications (~100 °C). First, extrusion compounding of Poly(l‐lactic acid) (PLLA)‐based biodegradable polyester blends was performed. In particular, the effect on the material properties of different types of nucleating agents was investigated. Combinations of micro‐lamellar talc, poly(d‐lactic acid) (PDLA), ethylene bisstearamide (EBS), and titanium dioxide (TiO2) were studied. The formulations involving EBS boast the highest crystallinity and the fastest onset of the crystalline phase on sheets produced by cast extrusion. Conversely, the formulations involving TiO2 feature the lowest degree of crystallinity and the slowest onset of the crystalline phase. Combinations of talc and PDLA exhibit an intermediate behavior. Second, thermoforming of the plastic foils was performed. A very different trend of the crystallization after thermoforming is shown. Indeed, crystallinity is the highest for the formulations involving talc and PDLA, the lowest for the ones containing EBS. In conclusion, the biodegradable polyester blends are found to be suitable for the manufacturing of compostable and thermostable packaging items by cast extrusion and thermoforming. Final crystallization of the material and the resulting thermal stability can be fine‐tuned by modulating type and amount of nucleating agents. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48722.
In‐Situ Growth and Immobilization of CdS Nanoparticles onto Functionalized MoS2: Preparation, Characterization and Fabrication of Photoelectrochemical Cells
Authors: Kagkoura Antonia , Hernandez‐Ferrer Javier , Benito Ana M. , Maser Wolfgang K. , Tagmatarchis Nikos 
Published: November 2019

AbstractA facile strategy for the controllable growth of CdS nanoparticles at the periphery of MoS2 en route the preparation of electron donor‐acceptor nanoensembles is developed. Precisely, the carboxylic group of α‐lipoic acid, as addend of the modified MoS2 obtained upon 1,2‐dithiolane functionalization, was employed as anchor site for the in situ preparation and immobilization of the CdS nanoparticles in an one‐pot two‐step process. The newly prepared MoS2/CdS hybrid material was characterized by complementary spectroscopic, thermal and microscopy imaging means. Absorption spectroscopy was employed to register the formation of MoS2/CdS, by observing a broad shoulder centered at 420 nm due to CdS nanoparticles, while the excitonic bands of MoS2 were also evident. Moreover, based on the efficient quenching of the characteristic fluorescence emission of CdS at 725 nm by the presence of MoS2, strong electronic interactions at the excited state between the two species within the ensemble were identified. Photoelectrochemical assays of MoS2/CdS thin‐film electrodes revealed a prompt, steady and reproducible anodic photoresponse during repeated on‐off cycles of illumination. A significant zero‐current photopotential of −540 mV and an anodic photocurrent of 1 μA were observed, underlining improved charge‐separation and electron transport from CdS to MoS2. The superior performance of the charge‐transfer processes in MoS2/CdS is of direct interest for the fabrication of photoelectrochemical and optoelectronic devices.
Proton‐Conductive 3D LnIII Metal–Organic Frameworks for Formic Acid Impedance Sensing
Authors: Liu Rui‐Lan , Qu Wan‐Ting , Dou Bao‐Heng , Li Zi‐Feng , Li Gang 
Published: November 2019

AbstractMetal‐organic frameworks (MOFs) as new classes of proton‐conducting materials have been highlighted in recent years. Nevertheless, the exploration of proton‐conducting MOFs as formic acid sensors is extremely lacking. Herein, we prepared two highly stable 3D isostructural lanthanide(III) MOFs, {(M(μ3‐HPhIDC)(μ2‐C2O4)0.5(H2O))⋅2 H2O}n (M=Tb (ZZU‐1); Eu (ZZU‐2)) (H3PhIDC=2‐phenyl‐1H‐imidazole‐4,5‐dicarboxylic acid), in which the coordinated and uncoordinated water molecules and uncoordinated imidazole N atoms play decisive roles for the high‐performance proton conduction and recognition ability for formic acid. Both ZZU‐1 and ZZU‐2 show temperature‐ and humidity‐dependent proton‐conducting characteristics with high conductivities of 8.95×10−4 and 4.63×10−4 S cm‐1 at 98 % RH and 100 °C, respectively. Importantly, the impedance values of the two MOF‐based sensors decrease upon exposure to formic acid vapor generated from formic aqueous solutions at 25 °C with good reproducibility. By comparing the changes of impedance values, we can indirectly determine the concentration of HCOOH in aqueous solution. The results showed that the lowest detectable concentrations of formic acid aqueous solutions are 1.2×10−2 mol L−1 by ZZU‐1 and 2.0×10−2 mol L−1 by ZZU‐2. Furthermore, the two sensors can distinguish formic acid vapor from interfering vapors including MeOH, N‐hexane, benzene, toluene, EtOH, acetone, acetic acid and butane. Our research provides a new platform of proton‐conductive MOFs‐based sensors for detecting formic acid.
Vibration activates the actin/NF‐κB axis and upregulates IL‐6 and IL‐8 expression in human periodontal ligament cells
Authors: Phusuntornsakul Pussadee , Jitpukdeebodintra Suwanna , Pavasant Prasit , Leethanakul Chidchanok 
Published: November 2019

AbstractWe previously reported that mechanical vibration‐induced proinflammatory cytokines, interleukin‐6 (IL‐6) and IL‐8, expression in human periodontal ligament (hPDL) cells, however, the underlying mechanism remained unclear. Mechanical stimuli are able to activate cellular responses by inducing the activation of several signaling pathways including cytoskeletal changes and inflammation. The actin cytoskeleton is a highly dynamic network and plays many important roles in intracellular events. Here, we aimed to investigate the involvement of a pivotal mediator of inflammatory responses, nuclear factor‐κB (NF‐κB), and actin polymerization in vibration‐induced upregulation of IL‐6 and IL‐8 expression in hPDL cells. hPDL cells were pretreated with the NF‐κB inhibitor BAY 11‐7082 or cytochalasin D, respectively, before exposure to vibration. IL‐6 and IL‐8 messenger RNA (mRNA) and protein expression were quantified by quantitative polymerase chain reaction and enzyme‐linked immunosorbent assays, respectively. Subcellular localization of the NF‐κB p65 subunit was visualized by immunofluorescent staining. We found an increase in NF‐κB nuclear translocation in vibrated cells compared with control cells. Pretreatment with BAY 11‐7082 significantly inhibited vibration‐induced IL‐6 and IL‐8 mRNA and protein expression in hPDL cells. Moreover, pretreatment with cytochalasin D inhibited NF‐κB nuclear translocation and attenuated upregulation of IL‐6 and IL‐8 mRNA and protein in vibrated cells. Therefore, modulation of actin cytoskeletal polymerization in response to vibration may activate the NF‐κB signaling pathway and subsequently upregulate IL‐6 and IL‐8 expression in hPDL cells.
LUCAT1 contributes to MYRF‐dependent smooth muscle cell apoptosis and may facilitate aneurysm formation via the sequestration of miR‐199a‐5p
Authors: Xia Qian , Zhang Liwei , Yan Hao , Yu Long , Shan Wei , Jiang Hong 
Published: November 2019

AbstractThe overwhelming number of interrogations reveals the implication of long noncoding RNAs (lncRNAs) in diverse malignancies, little is unveiled about lncRNAs participation in the abdominal aortic aneurysm (AAA). The study aimed to monitor the role and responsible mechanism of LUCAT1 in AAA. The cellular function of LUCAT1 on smooth muscle cells (SMCs) proliferation and apoptosis were examined through the conduction of CCK‐8, EdU, TUNEL, and caspase‐3 activity assays. LUCAT1 depletion was observed to boost SMCs proliferation or suppress SMCs apoptosis. The opposite results on SMCs proliferation and apoptosis were achieved in response to LUCAT1 promotion. The abundance of LUCAT1 in the cytoplasm was ascertained by subcellular fractionation and FISH analyses on the basis of LncLocator prediction. The binding of LUCAT1 to miR‐199a‐5p predicted by DIANA and starbase was certified by luciferase reporter assay and RIP analysis. Besides, multiple prediction tools unveiled the interaction between miR‐199a‐5p and myelin regulatory factor (MYRF). Quantitative real‐time polymerase chain reaction uncovered the suppressive effect of miR‐199a‐5p and the positive regulation of LUCAT1 on MYRF expression. Rescue experiments revealed that LUCAT1 depletion pose suppression on SMCs apoptosis and MYRF elevation abrogated this suppression induced by LUCAT1 inhibition. These findings unmasked that the pro‐apoptosis impact of LUCAT1 in SMCs via directly targeting miR‐199a‐5p to elevate MYRF expression, which may provide valuable information on AAA prevention.
Neurotoxicities associated with checkpoint inhibitors: Two case reports and a review of the literature
Authors: Cordes Lisa M. , Davarpanah Nicole N. , Reoma Lauren B. , Gasmi Billel , Quezado Martha , Khan Omar I. , Nath Avindra , Apolo Andrea B. 
Published: November 2019

AbstractWe report a case of nivolumab‐induced delayed‐onset aseptic meningitis and a case of limbic encephalitis and peripheral nerve palsy with toxicity relapse 6 months after initial presentation. The atypical presentations contribute to our knowledge of these rare events and reinforce the necessity for vigilant monitoring and a multidisciplinary treatment approach.
Sandwiched NiO/β‐Mo2C/RGO as Improved Electrocatalyst for Hydrogen Evolution Reaction: Solvothermal‐Assisted Self‐Assembly and Catalytic Mechanism
Authors: Ni Jiaqi , Ruan Zhuhua , Zhu Shufang , Kan Xianwen , Lu Lilin , Liu Yi 
Published: November 2019

AbstractMolybdenum carbide is a cost‐effective alternative to Pt‐group noble metal electrocatalyst for hydrogen evolution reaction (HER), developing a facile strategy to improve the HER activity of molybdenum carbide and understanding the mechanism is of great concern and challenging. Herein, a solvothermal‐assisted self‐assembly procedure of fabricating sandwiched NiO/β‐Mo2C/RGO nanocomposite catalyst was reported. Electrochemical measurements demonstrate that the catalytic activity and durability of β‐Mo2C can be significantly improved in the sandwiched NiO/β‐Mo2C/RGO. Comparative studies between various catalysts such as β‐Mo2C, NiO/β‐Mo2C, β‐Mo2C/RGO, and NiO/β‐Mo2C/RGO have been performed to explore the mechanism underpinning their different catalytic performance. Our results revealed that hybrid of β‐Mo2C and RGO resulted in significant improvement in electrical conductivity, NiO loading modified the electron density on the surface of β‐Mo2C (101) to the electron‐rich state to generate highly active catalytic site. The synergistic effect of RGO and NiO loading would be responsible for the improved electrocatalytic performance of the NiO/β‐Mo2C/RGO catalysts. The strategy developed in this work not only provides a new pathway for improving HER activity of molybdenum carbide but also deepens fundamental understandings on the structure‐reactivity of molybdenum carbide‐based nanocomposite catalysts with higher HER activity.
Combining Ionic Liquids and Sodium Salts into Metal‐Organic Framework for High‐Performance Ionic Conduction
Authors: Xu Qiuxia , Yang Fan , Zhang Xiangping , Li Jian‐Rong , Chen Jian‐Feng , Zhang Suojiang 
Published: November 2019

AbstractDeveloping stable conductive materials with high conductivity for sodium ion (Na+) batteries attracts ever‐increasing attention. In this work, MOF‐based solid Na+‐conducting composites functionalized by ionic liquids (ILs) were explored through introducing five kinds of ILs and their corresponding sodium salts into the pores of MIL‐101‐SO3Na. The pore‐filling fraction of MIL‐101‐SO3Na was established and revealed as a key factor to enhance the ionic conductivity of the composites. Na‐salts could further improved the conductivity by increasing the number of conductive ions. Furthermore, all ILs and Na‐salts@MIL‐101‐SO3Na hybrid composites showed sharply enhanced ionic conductivity and displayed low activation energy. Particularly, as the pore‐filling faction elevating to 96.94 % with [Emim][BF4] and NaBF4 in the pores of MIL‐101‐SO3Na the ionic conductivity reached up to 1.32×10−2 S cm−1 and stabilized within 30 days at 150 °C. This study on Na+‐conduction in a MOF‐based system functionalized by ILs, providing guidance for exploring new solid ionic conducting materials.
Basic Strategies and Types of Applications in Organic Electrochemistry
Authors: Hilt Gerhard 
Published: November 2019

AbstractThe outlook of this paper is to give a short overview of the basic requirements to perform electro‐organic transformations. The aim is to explain the strategies and possible applications in organic electrochemistry as simply as possible and is directed to those scientists who are not necessarily trained electrochemists and those that intend to utilize this powerful and, nowadays, very popular tool in their research. Different types of electrolysis performed in a galvanostatic/potentiostatic/alternating current fashion will be presented and the strategies to perform divided/undivided/quasi‐divided electrolysis will be covered. The application of direct/indirect/cation‐pool electrolysis as well as several variants of paired electrolysis will be briefly explained utilizing selected examples.
Comparison of two augmented classical least squares algorithms and PLS for determining nifuroxazide and its genotoxic impurities using UV spectroscopy
Authors: Hegazy Maha A. , Abdelwahab Nada S. , Ali Nouruddin W. , Sharkawi Marco M. Z. , Abdelkawy Mohamed M. , El‐Saadi Mohammed T. 
Published: November 2019

AbstractConcentration residual augmented classical least squares (CRACLS) and spectral residual augmented classical least squares (SRACLS) are reflecting the resolving power of spectrophotometric augmented mathematical techniques. The applied multivariate calibration methods were able to determine simultaneously the quinary mixture of nifuroxazide (NIF) and its four carcinogenic impurities, and a comparative study between the proposed models and the conventional partial least squares (PLS) algorithm was also done. Regression models were built covering the range of 10.00 to 50.00 μg mL−1 for NIF, 0.05 to 0.45 μg mL−1 (for each of impurities A and B), and 0.10 to 0.90 μg mL−1 (for impurities C and D). NIF and its four genotoxic impurities were successfully determined in the prepared mixtures and dosage forms. The efficiency of the applied algorithm for resolution and quantitation of the overlapped UV signals were compared, and the advantages over PLS mode were emphasized. The obtained results were statistically compared with each other along with those of the reported method.
Synthesis of C12‐Keto Saxitoxin Derivatives with Unusual Inhibitory Activity Against Voltage‐Gated Sodium Channels
Authors: Adachi Kanna , Yamada Tomoshi , Ishizuka Hayate , Oki Mana , Tsunogae Shunsuke , Shimada Noriko , Chiba Osamu , Orihara Tatsuya , Hidaka Masafumi , Hirokawa Takatsugu , Odagi Minami , Konoki Keiichi , Yotsu‐Yamashita Mari , Nagasawa Kazuo 
Published: November 2019

AbstractA novel series of C12‐keto‐type saxitoxin (STX) derivatives bearing an unusual nonhydrated form of the ketone at C12 has been synthesized, and their NaV‐inhibitory activity has been evaluated in a cell‐based assay as well as whole‐cell patch‐clamp recording. Among these compounds, 11‐benzylidene STX (3 a) showed potent inhibitory activity against neuroblastoma Neuro 2A in both cell‐based and electrophysiological analyses, with EC50 and IC50 values of 8.5 and 30.7 nm, respectively. Interestingly, the compound showed potent inhibitory activity against tetrodotoxin‐resistant subtype of NaV1.5, with an IC50 value of 94.1 nm. Derivatives 3 a–d and 3 f showed low recovery rates from NaV1.2 subtype (ca 45–79 %) compared to natural dcSTX (2), strongly suggesting an irreversible mode of interaction. We propose an interaction model for the C12‐keto derivatives with NaV in which the enone moiety in the STX derivatives 3 works as Michael acceptor for the carboxylate of Asp1717.
Hetero Diels–Alder Reactions of Masked Dienes Containing Heavy Group 15 Elements
Authors: Kořenková Monika , Kremláček Vít , Hejda Martin , Turek Jan , Khudaverdyan Raffi , Erben Milan , Jambor Roman , Růžička Aleš , Dostál Libor 
Published: November 2019

AbstractTreatment of N,C,N‐chelated organopnictogen(I) compounds ArE (1–3) (Ar=2,6‐(RN=CH)2C6H3, E/R=As/Dmp (1), Sb/tBu (2), and Bi/tBu (3), where Dmp=2,6‐Me2C6H3) with various electron‐deficient alkynes RC≡CR′ (R/R′=CO2Me (DMAD), R/R′=H/CO2Me, or R/R′=NC5F4) affords different types of heterocyclic compounds. In these reactions, 1–3 act as hidden dienes and participate in hetero‐Diels–Alder (DA) reactions, a feature that has been only rarely reported for heavier pnictogen compounds. In this way, reactions of 1 furnished the set of 1‐arsanaphthalenes 4–6. The most likely mechanism involves two steps, that is, an arsa‐DA reaction giving a 1‐arsa‐1,4‐dihydro‐iminonaphthalene, followed by CH→NH proton migration. In contrast, this reaction sequence terminates at the first step in the case of the antimony analogue 2, thus giving the 1‐stiba‐1,4‐dihydro‐iminonaphthalenes 7 and 8. Reactions of the bismuth congener 3 gave one of two products depending on the alkyne used. Reaction of 3 with DMAD gave 1‐bisma‐1,4‐dihydro‐iminonaphthalene 9, whilst its reaction with two equivalents of HC≡C(CO2Me) gave bismacyclohexadiene (10). All compounds have been characterized by NMR, IR, and Raman spectroscopies and X‐ray diffraction analysis. The experimental data were complemented by a computational study, including a description of the reaction profiles of the hetero‐DA reactions and an assessment of the aromaticities of the heterocyclic naphthalene derivatives.