bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Efficient Route to Isochromene Derivatives via Cascade Radical Cyclization and Radical‐Radical Coupling
Authors: Yu Kaili , Li Minyan , Deng Guogang , Liu Chunxiang , Wang Jing , Liu Zhengfen , Zhang Hongbin , Yang Xiaodong , Walsh Patrick J. 
Published: July 2019

AbstractIsochromenes are important pharmacophores present in biologically active molecules and natural products. Their synthesis is generally limited to cyclization of phenyl propargyl ether precursors under transition metal catalyzed conditions. Herein, we present a novel disconnection that rapidly constructs isochromene derivatives through a cascade radical cyclization strategy. Generation of aryl radicals by SET reduction of 2‐iodo benzyl allenyl ethers is followed by radical cyclization to construct the isochromene core with formation of an allylic radical. The allylic radical then undergoes coupling with the azaallyl radical to give products in good to excellent yields. The elaborated 2‐iodo phenyl propargyl ether precursors can be used to construct isochromenes bearing various functional groups.magnified image
Formation of Carbon‐Carbon Double Bonds: Recent Developments via Nitrous Acid Elimination (NAE) from Aliphatic Nitro Compounds
Authors: Ballini Roberto , Palmieri Alessandro 
Published: July 2019

AbstractAliphatic nitro compounds having an acidic hydrogen in the β‐position, with respect to the nitro group, are prone to undergo the elimination of nitrous acid, mainly under basic conditions, affording a C=C double bond. Until a few decades ago, the literature reported some examples of the application of this elimination as a strategic step in the synthesis of a variety of important targets. However, mainly in the last two decades, this methodology has been largely developed and applied, thus the aim of this review is to report the most important recent improvements.magnified image
Ferromagnet/Superconductor Hybrid Magnonic Metamaterials
Authors: Golovchanskiy Igor A. , Abramov Nikolay N. , Stolyarov Vasily S. , Dzhumaev Pavel S. , Emelyanova Olga V. , Golubov Alexander A. , Ryazanov Valery V. , Ustinov Alexey V. 
Published: July 2019

AbstractIn this work, a class of metamaterials is proposed on the basis of ferromagnet/superconductor hybridization for applications in magnonics. These metamaterials comprise of a ferromagnetic magnon medium that is coupled inductively to a superconducting periodic microstructure. Spectroscopy of magnetization dynamics in such hybrid evidences formation of areas in the medium with alternating dispersions for spin wave propagation, which is the basic requirement for the development of metamaterials known as magnonic crystals. The spectrum allows for derivation of the impact of the superconducting structure on the dispersion: it takes place due to a diamagnetic response of superconductors on the external and stray magnetic fields. In addition, the spectrum displays a dependence on the superconducting critical state of the structure: the Meissner and the mixed states of a type II superconductor are distinguished. This dependence hints toward nonlinear response of hybrid metamaterials on the magnetic field. Investigation of the spin wave dispersion in hybrid metamaterials shows formation of allowed and forbidden bands for spin wave propagation. The band structures are governed by the geometry of spin wave propagation: in the backward volume geometry the band structure is conventional, while in the surface geometry the band structure is nonreciprocal and is formed by indirect band gaps.
Methyl Trifluoroacetate as a Methylation Reagent for N−H, O−H, and S−H Functionalities under Mild Conditions
Authors: Zheng Xin , Zeng Jiechun , Xiong Mindong , Huang Jiawei , Li Cuiyan , Zhou Rujin , Xiao Duoduo 
Published: July 2019

AbstractA methylation reagent for compounds bearing N−H, O−H, and S−H functionalities was developed. Methyl trifluoroacetate (MTFA) was commonly considered as trifluoroacetylating reagent or trifluoromethylating reagent. In this work, we report the methylation behavior of MTFA under mild conditions with good functional group tolerance, allowing the transformation of a wide range of substrates, including N,H‐heteroaromatic compounds, phenolic compounds, carboxylic acids, thiophenols, secondary amides and imides, in high yields. This method was preliminarily applied to the chemoselective methylation of bifunctionalized secondary amide.
Synthesis of Functionalized α‐Vinyl Aldehydes from Enaminones
Authors: Chen Jie , Guo Pan , Zhang Jianguo , Rong Jiaxin , Sun Wangbin , Jiang Yaojia , Loh Teck‐Peng 
Published: July 2019

AbstractAn efficient RhII‐catalyzed synthesis of functionalized α‐vinyl aldehydes with high E/Z stereoselectivity was developed. The reaction mediates the cyclopropanation of enaminones with vinyl carbenoids that are generated from cyclopropenes in situ to give the aminocyclopropane intermediates. Selective C−C bond cleavage of the cyclopropane intermediates leads to formation of α‐vinyl aldehyde derivatives with high E/Z selectivity. This method proceeds at room temperature under very mild reaction conditions and works with a broad substrate scope.
Organic Semiconducting Pro‐nanostimulants for Near‐Infrared Photoactivatable Cancer Immunotherapy
Authors: Li Jingchao , Cui Dong , Huang Jiaguo , He Shasha , Yang Zebin , Zhang Yan , Luo Yu , Pu Kanyi 
Published: July 2019

AbstractIn this study, an organic semiconducting pro‐nanostimulant (OSPS) with a near‐infrared (NIR) photoactivatable immunotherapeutic action for synergetic cancer therapy is presented. OSPS comprises a semiconducting polymer nanoparticle (SPN) core and an immunostimulant conjugated through a singlet oxygen (1O2) cleavable linkers. Upon NIR laser irradiation, OSPS generates both heat and 1O2 to exert combinational phototherapy not only to ablate tumors but also to produce tumor‐associated antigens. More importantly, NIR irradiation triggers the cleavage of 1O2‐cleavable linkers, triggering the remote release of the immunostimulants from OSPS to modulate the immunosuppressive tumor microenvironment. Thus, the released tumor‐associated antigens in conjunction with activated immunostimulants induce a synergistic antitumor immune response after OSPS‐mediated phototherapy, resulting in the inhibited growth of both primary/distant tumors and lung metastasis in a mouse xenograft model, which is not observed for sole phototherapy.
Stereochemical Dichotomy in Two Competing Cascade Processes: Total Syntheses of Both Enantiomers of Spiroxin A
Authors: Ando Yoshio , Tanaka Daisuke , Sasaki Ryota , Ohmori Ken , Suzuki Keisuke 
Published: July 2019

AbstractThe first total synthesis of the marine antibiotic spiroxin A has been achieved for both enantiomeric forms. The discovery of two competing cascade processes triggered by two orthogonal stimuli, photo‐irradiation or acid/base treatment, enabled the divergent conversion of a single chiral, nonracemic bis‐quinone into both enantiomers of an advanced intermediate en route to both (−)‐ and (+)‐spiroxin A. The mechanism of the enantiodivergence is discussed.
Preserved in a Shell: High‐Performance Graphene‐Confined Ruthenium Nanoparticles in Acetylene Hydrochlorination
Authors: Kaiser Selina K. , Lin Ronghe , Krumeich Frank , Safonova Olga V. , Pérez‐Ramírez Javier 
Published: July 2019

AbstractThe potential implementation of ruthenium‐based catalysts in polyvinyl chloride production via acetylene hydrochlorination is hindered by their inferior activity and stability compared to gold‐based systems, despite their 4‐fold lower price. Combining in‐depth characterization and kinetic analysis we reveal the superior activity of ruthenium nanoparticles with an optimal size of 1.5 nm hosted on nitrogen‐doped carbon (NC) and identify their deactivation modes: 1) nanoparticle redispersion into inactive single atoms and 2) coke formation at the metal sites. Tuning the density of the NC carrier enables a catalytic encapsulation of the ruthenium nanoparticles into single layer graphene shells at 1073 K that prevent the undesired metal redispersion. Finally, we show that feeding O2 during acetylene hydrochlorination limits coke formation over the nanodesigned ruthenium catalyst, while the graphene layer is preserved, resulting in a stability increase of 20 times, thus rivalling the performance of gold‐based systems.
From modeling to virtual laboratory development of a continuous binary distillation column for engineering education using MATLAB and LabVIEW
Authors: Szávuly Miklós István , Tóos Áron , Barabás Réka , Szilágyi Botond 
Published: July 2019

AbstractThe utilization of computers in all aspects and scales of chemical engineering, from fundamental understanding to solution of large‐scale optimizations, is spreading quickly, hand‐in‐hand with access to data science and information technology. It is straightforward to involve computers and virtual laboratory tools into engineering education. This study presents the development of an interactive virtual laboratory method for a continuous binary distillation process. The three main steps, namely, mathematical modeling, model calibration, and graphical user interface (GUI) development are described and discussed in this paper. The model takes into account the specific needs of the simulator (fast run time) and limitations from the measurement system (calibration considerations). Then, it is validated based on temperature and concentration data from a lab/pilot scale continuous rectification column. The separation of an ethanol–water mixture is considered, the classroom example of distillation, which is, on the other hand, an azeotrope‐forming nonideal mixture. The objective of this paper, beyond the virtual laboratory coding description, is to provide useful guidelines for a user‐friendly and yet realistic simulator development for commonly available experimental devices in chemical engineering education. To fulfill this aim, MATLAB and LabVIEW, two routinely used programming languages by chemical and process engineers, are used.
Living with advanced cancer: Rich Pictures as a means for health care providers to explore the experiences of advanced cancer patients
Authors: Bood Zarah M. , Scherer‐Rath Michael , Sprangers Mirjam A. G. , Timmermans Liesbeth , van Wolde Ellen , Cristancho Sayra M. , Heyning Fenna , Russel Silvia , van Laarhoven Hanneke W. M. , Helmich Esther 
Published: July 2019

AbstractBackgroundTo provide holistic care to patients with advanced cancer, health care professionals need to gain insight in patients’ experiences across the different domains of health. However, describing such complex experiences verbally may be difficult for patients. The use of a visual tool, such as Rich Pictures (RPs) could be helpful. We explore the use of RPs to gain insight in the experiences of patients with advanced cancer.MethodsEighteen patients with advanced cancer were asked to draw a RP expressing how they experienced living with cancer, followed by a semi‐structured interview. Qualitative content analysis, including the examination of all elements in the drawings and their interrelationships, was used to analyze the RPs, which was further informed by the interviews.ResultsThe RPs clearly showed what was most important to an individual patient and made relations between elements visible at a glance. Themes identified included: medical aspects, the experience of loss, feelings related to loss, support from others and meaningful activities, and integration of cancer in one's life. The added value of RPs lies in the ability to represent these themes in one single snapshot.ConclusionsRPs allow for a complementary view on the experiences of advanced cancer patients, as they show and relate different aspects of patients’ lives. A RP can provide health care professionals a visual summary of the experiences of a patient. For patients, telling their story to health care professionals might be facilitated when using RPs.
TYK2 promotes malignant peripheral nerve sheath tumor progression through inhibition of cell death
Authors: Qin Wenjing , Godec Abigail , Zhang Xiaochun , Zhu Cuige , Shao Jieya , Tao Yu , Bu Xianzhang , Hirbe Angela C. 
Published: July 2019

AbstractBackgroundMalignant peripheral nerve sheath tumors (MPNSTs) are aggressive sarcomas that arise most commonly in the setting of the Neurofibromatosis Type 1 (NF1) cancer predisposition syndrome. Despite aggressive multimodality therapy, outcomes are dismal and most patients die within 5 years of diagnosis. Prior genomic studies in our laboratory identified tyrosine kinase 2 (TYK2) as a frequently mutated gene in MPNST. Herein, we explored the function of TYK2 in MPNST pathogenesis.MethodsImmunohistochemistry was utilized to examine expression of TYK2 in MPNSTs and other sarcomas. To establish a role for TYK2 in MPNST pathogenesis, murine and human TYK2 knockdown and knockout cells were established using shRNA and CRISPR/Cas9 systems, respectively.ResultsWe have demonstrated that TYK2 was highly expressed in the majority of human MPNSTs examined. Additionally, we demonstrated that knockdown of Tyk2/TYK2 in murine and human MPNST cells significantly increased cell death in vitro. These effects were accompanied by a decrease in the levels of activated Stats and Bcl‐2 as well as an increase in the levels of Cleaved Caspase‐3. In addition, Tyk2‐KD cells demonstrated impaired growth in subcutaneous and metastasis models in vivo.ConclusionTaken together, these data illustrate the importance of TYK2 in MPNST pathogenesis and suggest that the TYK2 pathway may be a potential therapeutic target for these deadly cancers.
Electrochemical Oxygen Reduction Reaction Performance Boosted by N, P Doped Carbon Layer over Manganese Dioxide Nanorod
Authors: Pei Chengang , Ding Ruifu , Yu Xu , Feng Ligang 
Published: July 2019

AbstractHerein, heteroatoms of N and P doped carbon layer over MnO2 nanorods surface was fabricated by an in situ anile polymerization reaction based on aniline and phytic acid (MnO2@PANI) following thermal annealing. A core‐shell structure with manganese oxide as the core and N, P‐doped carbon layer as the shell was revealed by structure and morphology analysis. Temperature dependence of phase structure and ORR activity was found by a series of physical and electrochemical studies for MnO2@PANI sample obtained at different annealing temperatures. The MnO2@PANI obtained at 800 °C exhibited the best catalytic performance, close to Pt/C for ORR; Specifically, the onset potential and half‐wave potential were 0.92 and 0.76 V respectively, outperforming their counterparts of MnO2 and N, P−C alone. The improved catalytic performance can be attributed to the conductivity improvement and the synergistic effect of the intrinsic activity of manganese oxide and N, P‐doped carbon layer. The current work demonstrated an efficient approach to boost the catalytic performance for ORR catalyzed by manganese oxide.
The Special “Morse Code” between Solvent Polarity and Morphology Flexibility in a POSS–Dendrimer Supramolecular System
Authors: Shan Tianyu , Gao Liang , Tong Xiaoqian , Du Qinqing , An Zhihang , He Huiwen , Lin Jiaping , Chen Si , Wang Xu 
Published: July 2019

AbstractAn amazing phenomenon of the relative magnitude of modulus of two liquid‐crystal (LC) gels is found inverted under/above their phase transition temperature TLC‐iso, which is further proved to be caused by their diverse morphology flexibility. By testing the polarity of two LCs, gelator POSS‐G1‐Boc (POSS=polyhedral oligomeric silsesquioxane) was discovered to self‐assemble into more flexible structures in a relatively low polar LC, whereas more rigid ones are formed in higher polar LC. Hence, a fitting function to connect morphology flexibility with solvent polarity was established, which can even be generalized to a number of common solvents. Experimental observations and coarse‐grained molecular dynamics simulations revealed that solvent polarity mirrors a “Morse code”, with each “code” corresponding to a specific morphology flexibility.
Selective Recognition of Phenazine by 2,6‐Dibutoxylnaphthalene‐Based Tetralactam Macrocycle
Authors: Wang Li‐Li , Tu Yi‐Kuan , Valkonen Arto , Rissanen Kari , Jiang Wei 
Published: July 2019

Summary of main observation and conclusionA 2,6‐dibutoxylnaphthalene‐based tetralactam macrocycle was designed and synthesized. This macrocycle shows highly selective recognition to phenazine – a well‐known secondary metabolite in bacteria and an emerging disinfection byproduct in drinking water. In contrast, the macrocycle shows no binding to the structurally similar dibenzo‐1,4‐dioxin. It was revealed that hydrogen bonding, π‐π and σ‐π interactions are the major driving forces between phenazine and the new tetralactam macrocycle. A perfect complementarity in electrostatic potential surfaces may explain the high selectivity. In addition, the macrocycle shows fluorescent response to phenazine, demonstrating its potential in fluorescent detection of phenazine.
Crosslinking actin networks produces compressive force
Authors: Ma Rui , Berro Julien 
Published: July 2019

AbstractActin has been shown to be essential for clathrin‐mediated endocytosis in yeast. However, actin polymerization alone is likely insufficient to produce enough force to deform the membrane against the huge turgor pressure of yeast cells. In this paper, we used Brownian dynamics simulations to demonstrate that crosslinking of a meshwork of nonpolymerizing actin filaments is able to produce compressive forces. We show that the force can be up to several thousand pico‐Newtons if the crosslinker has a high stiffness. The force decays over time as a result of crosslinker turnover, and is a result of converting chemical binding energy into elastic energy.
Methyl Ketones from Municipal Solid Waste Blends by One‐Pot Ionic‐Liquid Pretreatment, Saccharification, and Fermentation
Authors: Yan Jipeng , Liang Ling , He Qian , Li Chenlin , Xu Feng , Sun Jian , Goh Ee‐Been , Konda N. V. S. N. Murthy , Beller Harry R. , Simmons Blake A. , Pray Todd R. , Thompson Vicki S. , Singh Seema , Sun Ning 
Published: July 2019

AbstractThe conversion of municipal solid waste (MSW) and lignocellulosic biomass blends to methyl ketones (MKs) was investigated by using bioderived ionic liquid (bionic liquid)‐based hydrolysates followed by fermentation with an engineered Escherichia coli strain. The hydrolysates were produced by a one‐pot process using six types of MSW–biomass blends, choline‐based bionic liquids, and commercial enzymes. Based on the sugar yields, one blend (corn stover/MSW=95:5, w/w) and two bionic liquids {cholinium lysinate ([Ch][Lys]) and cholinium aspartate ([Ch]2[Asp])} were selected for scale‐up studies. Maximum yields of 82.3 % glucose and 54.4 % xylose were obtained from the selected blend in the scale‐up studies (6 L), which was comparable with 83.6 % glucose and 52.8 % xylose obtained at a smaller scale (0.2 L). Comparable or higher yields of medium‐chain (C11–C17) MKs were achieved by using the MSW–biomass blend‐derived hydrolysates, relative to the sugar controls (glucose and xylose) with similar sugar feeding concentrations. Up to 1145 mg L−1 of MKs was produced by using MSW–biomass‐derived hydrolysates, and the MK titer decreased to 300 mg L−1 when the bionic‐liquid concentration in the hydrolysate increased from 1 to 2 %, indicative of bionic‐liquid inhibition. Technoeconomic analysis was conducted to investigate the economic potential of using the selected MSW–biomass blend as a feedstock to produce MKs.
A Facile Direct Route to N‐(Un)substituted Lactams by Cycloamination of Oxocarboxylic Acids without External Hydrogen
Authors: Li Hu , Wu Hongguo , Zhang Heng , Su Yaqiong , Yang Song , Hensen Emiel J. M. 
Published: July 2019

AbstractLactams are privileged in bioactive natural products and pharmaceutical agents and widely featured in functional materials. This study presents a novel versatile approach to the direct synthesis of lactams from oxocarboxylic acids without catalyst or external hydrogen. The method involves the in situ release of formic acid from formamides induced by water to facilitate efficient cycloamination. Water also suppresses the formation of byproducts. This unconventional pathway is elucidated by a combination of model experiments and density functional theory calculations, whereby cyclic imines (5‐methyl‐3,4‐dihydro‐2‐pyrrolone and its tautomeric structures) are found to be favorable intermediates toward lactam formation, in contrast to the conventional approach encompassing cascade reductive amination and cyclization. This sustainable and simple protocol is broadly applicable for the efficient production of various N‐unsubstituted and N‐substituted lactams.
Enhanced generation of intraluminal vesicles in neuronal late endosomes in the brain of a Down syndrome mouse model with endosomal dysfunction
Authors: D'Acunzo Pasquale , Hargash Tal , Pawlik Monika , Goulbourne Chris N. , Pérez‐González Rocío , Levy Efrat 
Published: July 2019

AbstractDown syndrome (DS) is a human genetic disease caused by trisomy of chromosome 21 and characterized by early developmental brain abnormalities. Dysfunctional endosomal pathway in neurons is an early event of DS and Alzheimer's disease. Recently, we have demonstrated that exosome secretion is upregulated in human DS postmortem brains, in the brain of the trisomic mouse model Ts[Rb(12.1716)]2Cje (Ts2) and by DS fibroblasts as compared with disomic controls. High levels of the tetraspanin CD63, a regulator of exosome biogenesis, were observed in DS brains. Partially blocking exosome secretion by DS fibroblasts exacerbated a pre‐existing early endosomal pathology. We thus hypothesized that enhanced CD63 expression induces generation of intraluminal vesicles (ILVs) in late endosomes/multivesicular bodies (MVBs), increasing exosome release as an endogenous mechanism to mitigate endosomal abnormalities in DS. Herein, we show a high‐resolution electron microscopy analysis of MVBs in neurons of the frontal cortex of 12‐month‐old Ts2 mice and littermate diploid controls. Our quantitative analysis revealed that Ts2 MVBs are larger, more abundant, and contain a higher number of ILVs per neuron compared to controls. These findings were further corroborated biochemically by Western blot analysis of purified endosomal fractions showing higher levels of ILVs proteins in the same fractions containing endosomal markers in the brain of Ts2 mice compared to controls. These data suggest that upregulation of ILVs production may be a key homeostatic mechanism to alleviate endosomal dysregulation via the endosomal–exosomal pathway.