bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enantioselective Synthesis of Arene cis‐Dihydrodiols from 2‐Pyrones
Authors: Liang Xiao‐Wei , Zhao Yunlong , Si Xu‐Ge , Xu Meng‐Meng , Tan Jia‐Hao , Zhang Zhi‐Mao , Zheng Cheng‐Gong , Zheng Chao , Cai Quan 
Published: July 2019

AbstractAn enantioselective chemical synthesis of arene cis‐dihydrodiols has been realized from 2‐pyrones through sequential ytterbium‐catalyzed asymmetric inverse‐electron‐demand Diels–Alder (IEDDA) reaction of 2‐pyrones and retro‐Diels–Alder extrusion of CO2. By using this strategy, a series of substituted arene cis‐dihydrodiols can be obtained efficiently with high enantioselectivity (>99 % ee in many cases). Based on this strategy, efficient and concise asymmetric total syntheses of (+)‐MK7607 and 1‐epi‐(+)‐MK7607 were accomplished.
Flame retardancy of ceramic‐based rigid polyurethane foam composites
Authors: Agrawal Anuja , Kaur Raminder , Singh Walia Ravinderjit 
Published: July 2019

ABSTRACTIn this work, ceramic fillers zirconia and alumina powder were incorporated in the rigid polyurethane foams derived from modified castor oil and their impact on the mechanical, thermal, and fire performances of composite foams have been analyzed. It was observed that the addition of ceramic filler showed improved mechanical and thermal properties and best properties were shown by 6% zirconia with compressive strength of 6.61 MPa and flexural strength of 5.72 MPa. Zirconia also demonstrated an increase in T5% up to 260 °C. Cone calorimetry shows a decrease in peak of heat release from 118 to 84 kW m−2 and 94 kW m−2 by the incorporation of alumina and zirconia powder, respectively. Furthermore, total heat release (THR), smoke production rate (SPR), and total smoke release (TSR) were also found to decrease remarkably on the incorporation of ceramic fillers. So, these fillers have a great potential as an additive to incorporate good mechanical, thermal, and fire properties in bio‐based rigid PU foams. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48250.
3D‐printable thermochromic acrylic resin with excellent mechanical performance
Authors: Duan A. , Li Y. , Li B. , Zhu P. 
Published: July 2019

ABSTRACTThis study demonstrated the feasibility of printing three‐dimensional (3D) hybrid objects based on acrylic photocurable formulations, with an additional function of thermochromic (TC) performance. In fact, directly mixing TC pigments into an acrylic resin (AR), led to a decrease of the mechanical properties like tensile strength and elongation. In order to address this problem, TC was modified by γ‐methacryloxypropyltrimethoxysilane before added into an AR (modified thermochromic [mTC] pigment). Compared with pure AR and TC/resin composite structures (TC/AR), the final mTC/acrylic resin (mTC/AR) exhibited a better performance of tensile strength and Young's modulus. Besides, they could be successfully fabricated into 3D structures by stereolithography method. More interestingly, mTC/AR 3D composite structures demonstrated a unique tunable TC property, which could be responsive to external temperature fields reversely. Thus, their TC property could find novel applications in smart temperature sensor technology, and other related technological applications. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48277.
Sulfonylpiperazines based on a flavone as antioxidant and cytotoxic agents
Authors: Patel Rahul V. , Mistry Bhupendra M. , Syed Riyaz , Parekh Nikhil M. , Shin Han‐Seung 
Published: July 2019

AbstractChrysin‐based sulfonylpiperazines 7a‐k were synthesized and investigated for their in vitro free radical scavenging potential as well as cytotoxic efficacies against selected cancer cell lines. Cytotoxicity of the new compounds toward noncancer cells was confirmed using the SRB assay against Madin–Darby Canine Kidney cells. Reaction of piperazine with different substituted benzenesulfonyl chlorides in triethylamine furnished sulfonylpiperazines (3a‐k), which were then allowed to react with 7‐(4‐bromobutoxy)‐5‐hydroxy‐2‐phenyl‐4H‐chromen‐4‐one (6) prepared reacting chrysin with 1,4‐dibromobutane to give the final derivatives 7a‐k. The results concluded that chrysin‐sulfonylpiperazines exerted better antioxidant and anticancer efficacies than previously studied chrysin‐piperazine precursors. For example, compounds 7h, 7j, and 7k with 4‐OCF3, 4‐OCH3, and 2,4‐diOCH3 groups exhibited the best antioxidant potential against 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) and 2,2′‐azino‐bis‐3‐ethylbenzothiazoline‐6‐sulfonic acid (ABTS) radicals. Moreover, halogenated analogues (7b, 7c, 7g, and 7h) demonstrated promising anticancer potential against SK‐OV3, HeLa, and HT‐29 cell lines, whereas those bearing a methoxy functional group (7j and 7k) had beneficial effects against the cell lines A‐549 and HT‐29. Thus, it can be confirmed from the bioassay results that the overall structural design as well as proper substitution is crucial to deliver the anticipated biological effects. Spectroscopic techniques such as FT‐IR, 1H NMR, 13C NMR, mass and elemental analysis (CHN) were carried out to confirm the final structures.
Synthesis and mycobacterial evaluation of 5‐substituted‐6‐acetyl‐2‐amino‐7‐methyl‐5,8‐dihydropyrido‐[2,3‐d]pyrimidin‐4(3H)‐one derivatives
Authors: Agre Neha , Degani Mariam , Gupta Antima , Bhakta Sanjib , Ray Mukti Kanta 
Published: July 2019

Abstract5‐Substituted‐6‐acetyl‐2‐amino‐7‐methyl‐5,8‐dihydropyrido[2,3‐d]pyrimidin‐4(3H)‐one derivatives were synthesized and evaluated against Mycobacterium tuberculosis H37Rv, Mycobacterium aurum, Escherichia coli, and Staphylococcus aureus as well as a human monocyte‐derived macrophage (THP‐1), and murine macrophage (RAW 264.7) cell lines to assess their antibacterial and cytotoxic potential, respectively. The compounds showed activity in the range of 1.95–125 µg/ml against M. tuberculosis but showed no activity against M. aurum, E. coli, and S. aureus, indicating selectivity towards slow‐growing mycobacterial pathogens. The compounds exhibited very low to no cytotoxicity up to 500 µg/ml concentration against eukaryotic cell lines. The most potent molecule, 2l, showed a minimum inhibitory concentration of 1.95 µg/ml against M. tuberculosis H37Rv and a selectivity index of >250 against both the eukaryotic cell lines. Furthermore, 2l showed moderate inhibition of whole‐cell mycobacterial drug‐efflux pumps when compared to verapamil, a known potent inhibitor of efflux pumps. Thus, derivative 2l was identified as an antituberculosis hit molecule, which could be used to yield more potent lead molecules.
Activated M2 Macrophages Contribute to the Pathogenesis of IgG4‐Related Disease via Toll‐like Receptor 7/Interleukin‐33 Signaling
Authors: Ishiguro Noriko , Moriyama Masafumi , Furusho Katsuhiro , Furukawa Sachiko , Shibata Takuma , Murakami Yusuke , Chinju Akira , Haque A. S. M. Rafiul , Gion Yuka , Ohta Miho , Maehara Takashi , Tanaka Akihiko , Yamauchi Masaki , Sakamoto Mizuki , Mochizuki Keita , Ono Yuko , Hayashida Jun‐Nosuke , Sato Yasuharu , Kiyoshima Tamotsu , Yamamoto Hidetaka , Miyake Kensuke , Nakamura Seiji 
Published: July 2019

ObjectiveIgG4‐related disease (IgG4‐RD) is a unique inflammatory disorder in which Th2 cytokines promote IgG4 production. In addition, recent studies have implicated the Toll‐like receptor (TLR) pathway. This study was undertaken to examine the expression of TLRs in salivary glands (SGs) from patients with IgG4‐RD.MethodsSGs from 15 patients with IgG4‐RD, 15 patients with Sjögren's syndrome (SS), 10 patients with chronic sialadenitis, and 10 healthy controls were examined histologically. TLR family gene expression (TLR‐1 through TLR‐10) was analyzed by DNA microarray in the submandibular glands (SMGs). Up‐regulation of TLRs was confirmed in SGs from patients with IgG4‐RD. Finally, the phenotype of human TLR‐7 (huTLR‐7)–transgenic C57BL/6 mice was assessed before and after stimulation with TLR agonist.ResultsIn patients with IgG4‐RD, TLR‐4, TLR‐7, TLR‐8, and TLR‐9 were overexpressed. Polymerase chain reaction validated the up‐regulation of TLR‐7 in IgG4‐RD compared with the other groups. Immunohistochemical analysis confirmed strong infiltration of TLR‐7–positive cells in the SGs of patients with IgG4‐RD. Double immunohistochemical staining showed that TLR‐7 expression colocalized with CD163+ M2 macrophages. After in vitro stimulation with a TLR‐7 agonist, CD163+ M2 macrophages produced higher levels of interleukin‐33 (IL‐33), which is a Th2‐activating cytokine. In huTLR‐7–transgenic mice, the focus and fibrosis scores in SMGs, pancreas, and lungs were significantly higher than those in wild‐type mice (P < 0.05). Moreover, the concentration of serum IgG, IgG1, and IL‐33 in huTLR‐7–transgenic mice was distinctly increased upon stimulation with a TLR‐7 agonist (P < 0.05).ConclusionTLR‐7–expressing M2 macrophages may promote the activation of Th2 immune responses via IL‐33 secretion in IgG4‐RD.
A new HPLC–MS/MS method for the simultaneous quantification of SGLT2 inhibitors and metformin in plasma and its application to a pharmacokinetic study in healthy volunteers
Authors: Dias Bruna Carolina Lui , Fachi Mariana Millan , de Campos Michel Leandro , Degaut Flávia Lada Degaut , Peccinini Rosângela Gonçalves , Pontarolo Roberto 
Published: July 2019

AbstractMonitoring the plasma concentrations of metformin and sodium‐glucose cotransporter‐2 inhibitors (canagliflozin, dapagliflozin and empagliflozin) is essential for pharmacokinetic and bioequivalence studies and therapeutic monitoring. The present work therefore aimed to develop and validate a high‐performance liquid chromatography coupled to tandem mass spectrometry (HPLC–MS/MS) method for the simultaneous quantification of these drugs in human plasma. The analyses were performed using an Agilent 1200 HPLC system coupled to an Applied Biosystems API 3200 triple quadrupole MS/MS with electrospray ionization in positive ion mode. After one‐step protein precipitation of plasma with acetonitrile containing 0.1% formic acid, chromatographic separation was achieved on an Xbridge C18 column, with a mobile phase consisting of a gradient of water and acetonitrile, both containing 1 mm ammonium formate and 0.1% formic acid. Quantification was performed in multiple reaction monitoring mode using m/z 130.1 → 71.1 for metformin, m/z 462.0 → 191.2 for canagliflozin, m/z 426.1 → 167.1 for dapagliflozin and m/z 468.0 → 354.9 for empagliflozin. The proposed method was validated and demonstrated to be adequate for the quantification of metformin, canagliflozin, dapagliflozin and empagliflozin for clinical monitoring, pharmacokinetics and bioequivalence studies.
Integrating multiple state‐of‐the‐art computer‐aided design tools in microelectronics circuit design classes
Authors: Abugharbieh Khaldoon , Marar Hazem W. 
Published: July 2019

AbstractDemand for microelectronics products has seen a recent explosion due to their increased adaption in high‐performance data storage, networking, and Internet of Things applications. Not only such products need to provide high performance, they are often integrated in mixed signal environments that include both analog and digital circuits. This has posed a challenge to faculty who teach microelectronics design in senior undergraduate and graduate electrical engineering courses. It is becoming increasingly difficult to upgrade microelectronics curricula, so students are enabled with the proper skills to utilize design tools presently common in the industry. This study provides a mechanism to integrate five state of the art design tools in one single design project. The tools are Custom Compiler, Hewlett Simulation Program with Integrated Circuit, verilog compiler simulator, IC Validator, and Design Complier. Students, through a design project, conduct the design, layout, and simulations of an static random‐access memory array. The project utilizes both the full‐custom and the semi‐custom flows. One full design is created and integrated where students do the design and layout of transistors in specific circuits and generate synthesized circuits automatically from a high‐level description language. This study can serve as a resource for senior undergraduate students, graduate students, faculty, and practicing engineers. Finally, it can help electrical engineering programs meet Accreditation Board for Engineering and Technology students’ outcome (k) which is an ability to use the techniques, skills, and modern engineering tools necessary for engineering practice.
Effects of temperature, water activity, and fungal isolate on ochratoxin A accumulation in oat grain inoculated with Penicillium verrucosum and development of a methodology to screen oat cultivars for ochratoxin A accumulation
Authors: Dhungana Bandana , Ali Shaukat , Byamukama Emmanuel , Krishnan Padmanaban , Wu Jixiang , Caffe‐Treml Melanie 
Published: July 2019

AbstractBackground and objectivesOchratoxin A (OTA) is one of the most prevalent mycotoxins in cereal grains. In temperate climates, Penicillium verrucosum is the primary OTA producer. Our objectives were (a) to determine the effects of various factors on OTA accumulation in oat grain inoculated with P. verrucosum and (b) to develop a method to screen oat cultivars for OTA accumulation.FindingsGrain samples from three oat cultivars were inoculated with three different isolates of P. verrucosum, incubated at two water activity levels (0.85 and 0.90 aw) and two temperatures (22.5 and 27.5°C) for 4, 7, and 10 weeks. A water activity of 0.90 and a temperature of 22.5°C provided the highest level of OTA accumulation. Isolate C1136‐1 was the highest OTA producer among the isolates of P. verrucosum studied. The longer the incubation period, the higher the OTA accumulation in oat grain samples was.ConclusionsThe P. verrucosum isolate, the water activity and temperature during incubation, and the incubation period, all had an effect on the level of OTA accumulation. Inoculating grains with isolate C84‐2 and incubating at 22.5°C and 0.90 aw for 7 weeks provided adequate conditions to screen oat cultivars for OTA accumulation.Significance and noveltyA new protocol was developed that can be used for discriminating among oat cultivars for level of OTA accumulation. It would ultimately help breeders and pathologists in selecting genotypes with reduced OTA accumulation.
Scapula alata as presenting symptom of Fanconi anemia: A case for serendipity
Authors: van Adrichem Renee , de Weger Vincent , Broere Daniel , van Herrewegen Femke , Amaya Jeremy , ten Tusscher Gavin William 
Published: July 2019

AbstractFanconi anemia is a recessive genetic disorder with a wide range of presenting symptoms, from multiple congenital defects to exclusively (pan) cytopenia. Scapula alata may be a rare symptom of FA.
Direct Synthesis of Hierarchical FeCu‐ZSM‐5 Zeolite with Wide Temperature Window in Selective Catalytic Reduction of NO by NH3
Authors: Yue Yuanyuan , Liu Ben , Lv Nangui , Wang Tinghai , Bi Xiaotao , Zhu Haibo , Yuan Pei , Bai Zhengshuai , Cui Qingyan , Bao Xiaojun 
Published: July 2019

AbstractIn this article, we report a one‐pot synthesis strategy to directly synthesize the hierarchical FeCu‐ZSM‐5 zeolite. Its physicochemical properties were studied by various characterization techniques and catalytic performance was tested in selective catalytic reduction (SCR) of NO with NH3 as reductant. The characterization results show that: compared with three reference zeolites Fe/ZSM‐5, Cu/ZSM‐5, and Fe/Cu/ZSM‐5 prepared through an incipient wetness impregnation method, the synthesized FeCu‐ZSM‐5 zeolite exhibits hierarchical micro‐mesoporous structures, more Fe3+ in zeolite framework, and larger isolated Cu2+ species. Therefore, when used as a catalyst in NH3‐SCR, the resulting hierarchical FeCu‐ZSM‐5 catalyst shows better catalytic performance (high NO conversion and N2 selectivity) in a wide temperature window and higher hydrothermal stability than the three reference catalysts. Our work provides a simple and facile route to prepare the promising NH3‐SCR catalyst for practical applications in controlling NOx emissions.
A Porous POSiSil Suited for Pressure‐Driven Reversible Confinement of Solutions: PSS‐2
Authors: Smet Sam , Verlooy Pieter , Pulinthanathu Sreeprasanth , Kirschhock Christine E. A. , Taulelle Francis , Breynaert Eric , Martens Johan A. 
Published: July 2019

AbstractPolyoligosiloxysilicone (POSiSil; designated PSS‐2) is a copolymer of double four‐ring (D4R) cyclosilicate and dimethylsiloxane. It is synthesized by linking D4R units in tetrabutylammonium cyclosilicate crystals with dimethyldichlorosilane. The structure of PSS‐2 was revealed using solid state NMR spectroscopy. In this 3D copolymer D4R units are connected systematically by short siloxane chains most likely composed of 2 to 3 dimethylsiloxane monomers. Controlling the conversion of the parent material allows for tuning the porosity of PSS‐2. Residual parent material is embedded inside PSS‐2 polymer and can be eliminated by calcination. This leaves nanovoids inside PSS‐2, which is moderately hydrophobic. Pressure‐driven intrusion–extrusion cycles of aqueous solution exhibit hysteresis, thus, PSS‐2 can be used as reversible confinement for liquids with a capacity of around 1000 mm3 g−1 in porosity.
Modified Isoindolediones as Bright Fluorescent Probes for Cell and Tissue Imaging
Authors: Vakuliuk Olena , Jun Yong Woong , Vygranenko Kateryna , Clermont Guillaume , Reo Ye Jin , Blanchard‐Desce Mireille , Ahn Kyo Han , Gryko Daniel T. 
Published: July 2019

AbstractNew L‐shaped fluorophores possessing five conjugated rings have been synthesized through a four‐step procedure involving diketopyrrolopyrrole synthesis and its double N‐alkylation, followed by trimethylsilyl bromide‐mediated rearrangement to thieno[2,3‐f]isoindole‐5,8‐dione and an intramolecular Friedel–Crafts reaction. In comparison with the parent isoindolediones and π‐expanded diketopyrrolopyrroles, these new dyes show red‐shifted absorption and emission (up to ≈630 nm). Their structural rigidity is responsible for both the observed small Stokes shifts and large fluorescence quantum yields. Tissue imaging studies revealed that these new dyes show advantageous features including minimal autofluorescence interference and pronounced solvent‐sensitive emission. Interestingly, there is a fundamental difference between a dye possessing an amino group and its analog bearing an N‐alkyl substituent. The former dye under two‐photon excitation at 900 nm gives bright images whereas its N‐alkylated counterpart does not. A new type of membrane localization has been discovered by an N‐alkylated isoindoledione possessing a benzofuryl substituent. In spite of the fact that the fluorescence quantum yield of this dye in a range of solvents is rather low, it does stain cell membranes exclusively. This new mode of cellular staining opens the door towards further development of membrane staining dyes.
15N Hyperpolarization of Dalfampridine at Natural Abundance for Magnetic Resonance Imaging
Authors: Skovpin Ivan V. , Svyatova Alexandra , Chukanov Nikita , Chekmenev Eduard Y. , Kovtunov Kirill V. , Koptyug Igor V. 
Published: July 2019

AbstractSignal Amplification by Reversible Exchange (SABRE) is a promising method for NMR signal enhancement and production of hyperpolarized molecules. As nuclear spin relaxation times of heteronuclei are usually much longer than those of protons, SABRE‐based hyperpolarization of heteronuclei in molecules is highly important in the context of biomedical applications. In this work, we demonstrate that the SLIC‐SABRE technique can be successfully used to hyperpolarize 15N nuclei in dalfampridine. The high polarization level of ca. 8 % achieved in this work made it possible to acquire 15N MR images at natural abundance of the 15N nuclei for the first time.
Amino Acid‐Derived Sensors for Specific Zn2+ Detection Using Hyperpolarized 13C Magnetic Resonance Spectroscopy
Authors: Wang Sinan , Korenchan David E. , Perez Paola M. , Taglang Céline , Hayes Thomas R. , Sriram Renuka , Bok Robert , Hong Andrew S. , Wu Yunkou , Li Henry , Wang Zhen , Kurhanewicz John , Wilson David M. , Flavell Robert R. 
Published: July 2019

AbstractAlterations in Zn2+ concentration are seen in normal tissues and in disease states, and for this reason imaging of Zn2+ is an area of active investigation. Herein, enriched [1‐13C]cysteine and [1‐13C2]iminodiacetic acid were developed as Zn2+‐specific imaging probes using hyperpolarized 13C magnetic resonance spectroscopy. [1‐13C]cysteine was used to accurately quantify Zn2+ in complex biological mixtures. These sensors can be employed to detect Zn2+ via imaging mechanisms including changes in 13C chemical shift, resonance linewidth, or T1.
Potassium Salts of 2,5‐Bis(trimethylsilyl)‐Germolide: Switching between Aromatic and Non‐Aromatic States
Authors: Dong Zhaowen , Schmidtmann Marc , Müller Thomas 
Published: July 2019

AbstractInvited for the cover of this issue is the group of Thomas Müller at the University of Oldenburg. The image depicts the switch between aromatic and non‐aromatic states of a potassium germacyclopentadienide triggered by complexation of the potassium cation. Read the full text of the article at 10.1002/chem.201902238.
On the role played by the chirality of ligands on the aggregation of heterometallic CuII‐HgII complexes
Authors: Maxim Catalin , Muntean Dorian , Andruh Marius 
Published: July 2019

AbstractCopper(II) complexes constructed from enantiopure Schiff‐base ligands derived from o‐vanillin and methionine or from their racemic mixture have been employed as metalloligands towards mercury(II) ions. The nature of the heterometallic CuII‐HgII complexes (coordination polymers or oligonucler species), resulted from the reactions of the copper(II) complexes with HgCl2 or HgI2, is different. The enantiopure metalloligands lead to chiral coordination polymers, 1∞[{Cu(R‐/S‐valmet)(H2O)}2HgCl2]·5H2O·CH3OH and 2∞[{Cu2(R‐/S‐valmet)2(μ‐H2O)(H2O)2}HgI2]·4H2O. The reaction of the racemic mixture of the metalloligands with HgX2 affords discrete complexes: [{Cu(R,S‐valmet)(H2O)2}2HgCl2]·2H2O and [{Cu(R,S‐valmet)(H2O)(CH3OH)}2Hg2I4].
Standortplanung für die Herstellung CO2‐basierter Chemikalien am Beispiel der Olefinproduktion
Authors: Thonemann Nils , Stießel Sebastian , Maga Daniel , Hiebel Markus , Dresen Boris , Hunstock Björn , Deerberg Görge , Weidner Eckhard 
Published: July 2019

AbstractDie rohstoffliche Nutzung von CO2 gewinnt in Anbetracht des Klimaschutzes und als alternative Rohstoffbasis zunehmend an Bedeutung. Sowohl elektrochemische Direktsynthesen als auch thermochemische Verfahren zur CO2‐Konversion gehen mit einem hohen Bedarf an elektrischer Energie einher. Ein Beitrag zum Klimaschutz ist nur im Fall einer CO2‐armen Stromerzeugung möglich, wie sie z. B. durch die Nutzung von Windkraft oder Solarenergie realisiert werden kann. Vor diesem Hintergrund präsentiert der vorliegende Artikel eine Methodik zur Identifizierung von geeigneten Standorten für die CO2‐basierte Produktion von Olefinen in Deutschland.