bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transforming Porous Organic Cages into Porous Ionic Liquids via a Supramolecular Complexation Strategy
Authors: Jie Kecheng , Onishi Nicole , Schott Jennifer A. , Popovs Ilja , Jiang De‐en , Mahurin Shannon , Dai Sheng 
Published: November 2019

AbstractPorous liquids are a type of porous materials that engineer permanent porosity into unique flowing liquids, exhibiting promising functionalities for a variety of applications. Here a Type I porous liquid is synthesized by transforming porous organic cages into porous ionic liquids via a supramolecular complexation strategy. Simple physical mixing of 18‐crown‐6 with task‐specific anionic porous organic cages affords a porous ionic liquid with anionic porous organic cages as the anionic parts and 18‐crown‐6/potassium ion complexes as the cationic parts. In contrast, mixing of 15‐crown‐5 and anionic porous organic cages in a 2:1 ratio gives only solids, while the addition of excess 15‐crown‐5 affords a Type II porous liquid. The permanent porosity in the cage‐based porous liquids has been also confirmed by molecular simulation, positron (e+) annihilation lifetime spectroscopy, and enhanced gas sorption capacity compared with pure crown ethers.
Enantioselective Synthesis of Multisubstituted Allenes by Cooperative Cu/Pd‐Catalyzed 1,4‐Arylboration of 1,3‐Enynes
Authors: Liao Yang , Yin Xuemei , Wang Xihong , Yu Wangzhi , Fang Dongmei , Hu Lianrui , Wang Min , Liao Jian 
Published: November 2019

AbstractA cooperative Cu/Pd‐catalyzed enantioselective synthesis of multisubstituted allenes is established. By employing chiral sulfoxide phosphine (SOP)/Cu and PdCl2(dppf) complexes as catalysts, the 1,4‐arylboration of 1,3‐enynes provides an efficient approach to trisubstituted chiral allenes with up to 92 % yield and 97:3 er. Furthermore, by using 2‐substituted 1,3‐enynes as substrates, the tetrasubstituted chiral allenes were successfully generated using this strategy. Finally, theoretical calculations indicate that the transmetallation of the allenylcopper species is the rate‐limiting step of this transformation.
Organic–Inorganic Copolymerization for a Homogenous Composite without an Interphase Boundary
Authors: Yu Yadong , Mu Zhao , Jin Biao , Liu Zhaoming , Tang Ruikang 
Published: November 2019

AbstractIonic oligomers and their crosslinking implies a possibility to produce novel organic–inorganic composites by copolymerization. Using organic acrylamide monomers and inorganic calcium phosphate oligomers as precursors, uniformly structured polyacrylamide (PAM)‐calcium phosphate copolymer is prepared by an organic–inorganic copolymerization. In contrast to the previous PAM‐based composites by mixing inorganic components into polymers, the copolymerized material has no interphase boundary owing to the homogenous incorporation of the organic and inorganic units at molecular level, resulting in a complete and continuous hybrid network. The participation of the ionic binding effect in the crosslinking process can substantially improve the mechanical strength; the copolymer can reach a modulus and hardness of 35.14±1.91 GPa and 1.34±0.09 GPa, respectively, which are far superior to any other PAM‐based composites.
Developing Luminescent Ratiometric Thermometers Based on a Covalent Organic Framework (COF)
Authors: Kaczmarek Anna M. , Liu Ying‐Ya , Kaczmarek Mariusz K. , Liu Hengshuo , Artizzu Flavia , Carlos Luís D. , Van Der Voort Pascal 
Published: November 2019

AbstractCovalent Organic Frameworks (COFs), an emerging class of crystalline porous materials, are proposed as a new type of support for grafting lanthanide ions (Ln3+) and employing these hybrid materials as ratiometric luminescent thermometers. A TpBpy‐COF—prepared from 1,3,5‐triformylphloroglucinol (Tp) and 2,2′‐bipyridine‐5,5′‐diamine (Bpy) grafted with Eu/Tb and Dy acetylacetone (acac) complexes can be successfully used as a luminescent thermometer in the 10–360 K (Eu) and 280–440 K (Tb) ranges with good sensing properties (thermal sensitivity up to 1.403 % K−1, temperature uncertainty δT<1 K above 110 K). For the Eu/Tb systems, we observe an unusual and rarely reported behavior, that is, no thermal quenching of the Tb3+ emission, a result of the absence of ion‐to‐ligand/host energy back‐transfer. The LnCOF materials proposed here could be a new class of materials employed for temperature‐sensing applications following up on the well‐known luminescent metal–organic framework thermometers.
High‐Resolution Electrochemical Mapping of the Hydrogen Evolution Reaction on Transition‐Metal Dichalcogenide Nanosheets
Authors: Takahashi Yasufumi , Kobayashi Yu , Wang Ziqian , Ito Yoshikazu , Ota Masato , Ida Hiroki , Kumatani Akichika , Miyazawa Keisuke , Fujita Takeshi , Shiku Hitoshi , Korchev Yuri E. , Miyata Yasumitsu , Fukuma Takeshi , Chen Mingwei , Matsue Tomokazu 
Published: November 2019

AbstractHigh‐resolution scanning electrochemical cell microscopy (SECCM) is used to image and quantitatively analyze the hydrogen evolution reaction (HER) catalytically active sites of 1H‐MoS2 nanosheets, MoS2, and WS2 heteronanosheets. Using a 20 nm radius nanopipette and hopping mode scanning, the resolution of SECCM was beyond the optical microscopy limit and visualized a small triangular MoS2 nanosheet with a side length of ca. 130 nm. The electrochemical cell provides local cyclic voltammograms with a nanoscale spatial resolution for visualizing HER active sites as electrochemical images. The HER activity difference of edge, terrace, and heterojunction of MoS2 and WS2 were revealed. The SECCM imaging directly visualized the relationship of HER activity and number of MoS2 nanosheet layers and unveiled the heterogeneous aging state of MoS2 nanosheets. SECCM can be used for improving local HER activities by producing sulfur vacancies using electrochemical reaction at the selected region.
Yellow Circularly Polarized Luminescence from C1‐Symmetrical Copper(I) Complexes
Authors: Deng Min , Mukthar Nishya F. M. , Schley Nathan D. , Ung Gaël 
Published: November 2019

AbstractThe synthesis of chiral C1‐symmetrical copper(I) complexes supported by chiral carbene ligands is described. These complexes are yellow emitters with modest quantum yields. Circularly polarized luminescence (CPL) spectra show a polarized emission band with dissymmetry factors |glum|=1.2×10−3. These complexes are the first reported examples of molecular copper(I) complexes exhibiting circularly polarized luminescence. In contrast with most CPL‐emitting molecules, which possess either helical or axial chirality, the results presented show that simple chiral architectures are suitable for CPL emission and unlock new synthetic possibilities.
Polydimethylsiloxane/monomer casting nylon copolymers: Preparation, flame‐retardant properties, and wear‐resistant properties
Authors: Song Ling , Yang Haiyang , Li Duxin , Jiang Qibin , Zeng Dan 
Published: November 2019

ABSTRACTIn order to improve the toughness, wear resistance, and combustion properties of the monomer casting nylon (MC nylon) materials, the polydimethylsiloxane (PDMS) segment is bonded to the nylon molecular chain by copolymerization. PDMS/MC nylon copolymers are prepared via in situ anionic polymerization with macro‐activator based on PDMS terminated with hexamethylene diisocyanate. The effects of different macro‐activator content on the mechanical properties, water absorption, thermal stability, friction and wear properties, and combustion properties of the copolymers are characterized. The results show that the impact strength of the copolymer improves significantly (optimally increases by 2.6 times) and the water absorption rate decreases with the increase of PDMS content. The introduction of the silicon–oxygen structure reduces the peak heat release rate of copolymer materials (optimally decreases about 28.7%), while it promotes the decomposition of the system, resulting in a slight decrease in the thermal stability of the materials. Adding 5 wt % PDMS can decrease the wear loss of MC nylon from 6.2 mg of pure nylon to 1.6 mg. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48753.
The stability and antiapoptotic activity of Bm30K‐3 can be improved by lysine acetylation in the silkworm, Bombyx mori
Authors: Ma Yafei , Wu Chengcheng , Liu Jiahan , Liu Yue , Lv Jiao , Sun Zihan , Wang Dan , Jiang Caiying , Sheng Qing , You Zhengying , Nie Zuoming 
Published: November 2019

AbstractAcetylation is an important, highly conserved, and reversible post‐translational modification of proteins. Previously, we showed by nano‐HPLC/MS/MS that many nutrient storage proteins in the silkworm are acetylated. Among these proteins, most of the known 30K proteins were shown to be acetylated, including 23 acetylated 30K proteins containing 49 acetylated sites (Kac), indicating the importance of the acetylation of 30K proteins in silkworm. In this study, Bm30K‐3, a 30K protein containing three Kac sites, was further assessed in functional studies of its acetylation. Increasing the level of Bm30K‐3 acetylation by adding the deacetylase inhibitor trichostatin A (TSA) increased the levels of this protein and further inhibited cellular apoptosis induced by H2O2. In contrast, decreasing the level of acetylation by adding the acetylase inhibitor C646 could reduce the level of Bm30K‐3 and increase H2O2‐induced apoptosis. Subsequently, BmN cells were treated with CHX and MG132, and increasing the acetylation level using TSA was shown to inhibit protein degradation and improve the stability of Bm30K‐3. Furthermore, the acetylation of Bm30K‐3 could compete with its ability to be ubiquitinated, suggesting that acetylation could inhibit the ubiquitin‐mediated proteasome degradation pathway, improving the stability and accumulation of proteins in cells. These results further indicate that acetylation might regulate nutrition storage and utilization in Bombyx mori, which requires further study.
Thermosetting Shape Memory Polymers and Composites Based on Polybenzoxazine Blends, Alloys and Copolymers
Authors: Mora Phattarin , Schäfer Hannes , Jubsilp Chanchira , Rimdusit Sarawut , Koschek Katharina 
Published: November 2019

AbstractWhen dealing with smart polymers, in particular with shape memory polymers, the polymer type and composition specify the overall material properties and in particular the extent of the shape memory effect. Polybenzoxazines as a polymer with high potential for structural applications represent a promising component for materials with both shape memory effect and structurally interesting material properties. This minireview gives insight into how the shape memory effect, in particular the shape recovery event, is influenced by internal factors such as polymer structure, morphology and external factors such as filler addition.
Regulated Single‐Axis Rotations of a Carbonaceous Guest in a van der Waals Complex with an Entropy Cost
Authors: Matsuno Taisuke , Nakai Yusuke , Maniwa Yutaka , Someya Maki , Sato Sota , Isobe Hiroyuki 
Published: November 2019

AbstractIn a tight host–guest complex assembled solely by nondirectional van der Waals forces, unique motions of the guest, such as solid‐state inertial rotations, emerge. The regulation of dynamic motions is an important element to be explored for novel functions of such complexes, which may be seemingly difficult to achieve because of the nondirectionality of the assembling forces. A regulated, single‐axis rotation was made possible by choosing an appropriate shape of the guest in the tubular host. Specifically, an ellipsoidal guest was made to stand along a cylinder axis of the host, which consequently resulted in single‐axis rotations of the guest in the solid. The rotational frequency was considerably high for solid‐state rotations but was suppressed to 10 GHz, which was 1/20 of the isotropic rotation of a spherical guest. In‐depth kinetic analyses quantitatively revealed that the entropy cost was a determining factor that regulated the dynamics.
A tutorial on dynamic risk prediction of a binary outcome based on a longitudinal biomarker
Authors: Dandis Rana , Teerenstra Steven , Massuger Leon , Sweep Fred , Eysbouts Yalck , IntHout Joanna 
Published: November 2019

AbstractDynamic risk predictions based on all available information are useful in timely identification of high‐risk patients. However, in contrast with time to event outcomes, there is still a lack of studies that clearly demonstrate how to obtain and update predictions for a future binary outcome using a repeatedly measured biomarker. The aim of this study is to give an illustrative overview of four approaches to obtain such predictions: likelihood based two‐stage method (2SMLE), likelihood based joint model (JMMLE), Bayesian two‐stage method (2SB), and Bayesian joint model (JMB). We applied the approaches to provide weekly updated predictions of post–molar gestational trophoblastic neoplasia (GTN) based on age and repeated measurements of human chorionic gonadotropin (hCG). Discrimination and calibration measures were used to compare the accuracy of the weekly predictions. Internal validation of the models was conducted using bootstrapping. The four approaches resulted in the same predictive and discriminative performance in predicting GTN. A simulation study showed that the joint models outperform the two‐stage methods when we increase the within‐ and the between‐patients variability of the biomarker. The applicability of these models to produce dynamic predictions has been illustrated through a comprehensive explanation and accompanying syntax (R and SAS®).
How individuals change during internet‐based interventions for depression: A randomized controlled trial comparing standardized and individualized feedback
Authors: Zagorscak Pavle , Heinrich Manuel , Bohn Johannes , Stein Jana , Knaevelsrud Christine 
Published: November 2019

AbstractBackgroundStandardized and individualized Internet‐based interventions (IBI) for depression yield significant symptom improvements. However, change patterns during standardized or individualized IBI are unknown. Identifying subgroups that experience different symptom courses during IBI and their characteristics is vital for improving response.MethodsMildly to moderately depressed individuals according to self‐report (N = 1,089) were randomized to receive module‐wise feedback that was either standardized or individualized by a counselor within an otherwise identical cognitive‐behavioral IBI for depression (seven modules over six weeks). Depressive symptoms were assessed at baseline and before each module (Patient Health Questionnaire; PHQ‐9). Other individual characteristics (self‐report) and the presence of an affective disorder (structured clinical interview) were assessed at baseline. Growth mixture modeling was used to identify and compare subgroups with discernable change patterns and associated client variables across conditions.ResultsModel comparisons suggest equal change patterns in both conditions. Across conditions, a group of immediate (62.5%) and a group of delayed improvers (37.5%) were identified. Immediate improvers decreased their PHQ‐9 score by 5.5 points from pre to post, with 33% of improvement occurring before treatment commenced. Delayed improvers were characterized by stable symptom severity during the first two modules and smaller overall symptom decrease (3.4 points). Higher treatment expectations, a current major depressive disorder (interview), and lower social support were associated with delayed improvement.ConclusionInternet‐based interventions for depression with individualized and with standardized feedback lead to comparable patterns of change. Expectation management and bolstering of social support are promising strategies for individuals that are at risk for delayed improvement.
Introducing Excel spreadsheet calculations and numerical simulations with professional software into an undergraduate hydraulic engineering course
Authors: Bermúdez María , Puertas Jerónimo , Cea Luis 
Published: November 2019

AbstractThis paper presents a comprehensive set of computer tools for implementing an active teaching–learning strategy on an undergraduate hydraulic engineering course, within the subject blocks of pressure flow and free surface flow. The tools comprise a number of simple Excel‐based applications, to enhance students’ understanding of basic concepts, plus a series of practical exercises using the free professional models EPANET and IBER, aimed at familiarizing students with the tools used in real practice. The application of the new methodology to a hydraulics course at the Civil Engineering School of the University of A Coruña (Spain) resulted in increased student satisfaction and engagement, as well as greater interaction with instructors and classmates. The applications and practical exercises are easily adaptable and freely available to the community to facilitate their application to other courses and/or degrees.
Melatonin reverses the oxidative stress and mitochondrial dysfunction caused by LETM1 silencing
Authors: Aral Cenk , Demirkesen Seyma , Bircan Rıfat , Yasar Sirin Duygu 
Published: November 2019

AbstractLETM1 is a mitochondrial inner‐membrane protein, which is encoded by a gene present in a locus of 4p, which, in turn, is deleted in the Wolf–Hirschhorn Syndrome, and is assumed to be related to its pathogenesis. The cellular damage caused by the deletion is presumably related to oxidative stress. Melatonin has many beneficial roles in protecting mitochondria by scavenging reactive oxygen species, maintaining membrane potential, and improving functions. The aim of this study was to investigate the effects of melatonin administration to LETM1‐silenced mouse embryonic fibroblast cells as a cellular model for LETM1 deficiency. We transfected mouse embryonic fibroblast cells with a pair of siRNA against LETM1 and monitored the oxidative stress and mitochondrial functions with or without melatonin addition. MnSOD expression and aconitase activity decreased and oxidized protein levels increased in LETM1‐silenced cells. LETM1 suppression did not alter the expression of OXPHOS complexes, but the oxygen consumption rates decreased significantly; however, this change was not related to complex I but instead involved complex IV and complex II. Melatonin supplementation effectively normalized the parameters studied, including the oxygen consumption rate. Our findings identified a novel effect of LETM1 deficiency on cellular respiration via complex II as well as a potential beneficial role of melatonin treatment. On the other hand, these effects may be specific to the cell line used and need to be verified in other cell lines.
Intravascular ultrasound radiofrequency signal analysis of blood speckles: Physiological assessment of intermediate coronary artery stenosis
Authors: Okada Kozo , Hibi Kiyoshi , Matsushita Kensuke , Yagami Hiroyuki , Tamura Kouichi , Honda Yasuhiro , Kimura Kazuo 
Published: November 2019

AbstractBackgroundThis study aimed to systematically investigate feasibility of radiofrequency intravascular ultrasound (RF‐IVUS) analysis of blood signals for assessing functionally significant coronary stenosis.MethodsFirst, in‐vivo human study was performed to evaluate 83 intermediate coronary lesions from 75 patients, using 40‐MHz RF‐IVUS, fractional flow reserve (FFR) and instantaneous wave‐free ratio (iFR). Average blood integrated‐backscatter (IB) values within lumen were measured at proximal and distal segments to the stenosis; ΔIB values between the two sites were calculated. Second, bench‐test was performed to assess relationships of blood IB values to blood flow velocity and hematocrit using 40 and 60‐MHz RF‐IVUS.ResultsIn in‐vivo study, ΔIB values across the stenosis significantly correlated with both FFR (r = −.85, p < .0001) and iFR (r = −.65, p < .0001), which was confirmed in small minimum lumen area (MLA) lesions (MLA <2.0 mm2). Receiver operating characteristic curve analyses identified the best cut‐off value as 10.06 of ΔIB values for predicting FFR ≤0.8 and iFR ≤0.89 (sensitivity 76.2 and 95.5%, specificity 100 and 82.0%, positive predictive value 100 and 65.6%, negative predictive value 80.4 and 98.0%, accuracy 92.9 and 92.8% for FFR and iFR). Bench‐test study also identified that blood IB values exponentially changed as a function of blood flow velocity at any given hematocrit in both 40 and 60‐MHz RF‐IVUS.ConclusionsThis study supports the potential utility of RF‐IVUS analysis of blood signals to estimate functional ischemia, demonstrating relationships of blood ΔIB values to FFR and iFR, as well as relationships between blood IB values and flow velocity.
Flash Catalytic Pyrolysis of Polyethylene over (Alumino)silicate Materials
Authors: Klaimy Sophie , Ciotonea Carmen , Dhainaut Jérémy , Royer Sébastien , Casetta Mathilde , Duquesne Sophie , Tricot Grégory , Lamonier Jean‐François 
Published: November 2019

AbstractA series of amorphous and crystalline (alumino)silicate catalysts, with variable acidity, are evaluated for the flash pyrolysis of polyethylene (PE). Catalysts morphology, acidity as well as textural properties are influencing the process of decomposition of PE. Incomplete PE conversion and significant wax formation are obtained under the reaction condition with pure amorphous and MFI‐type silica. Complete conversion, and limited formation of wax, are observed with amorphous and MFI‐type Si−Al containing catalyst. Acidity has a significant influence on the molecule size and nature. Then, the increase of the catalyst acidity leads to the decrease of the molecular weight of pyrolysis products and the increase of the gas and the light liquid fractions. In addition, the acidity increase promotes cyclization reaction, resulting in the increase of the cycled hydrocarbon/aromatic proportion in the liquid fraction. Then, from PE catalytic pyrolysis, up to 25 wt.% of aromatics can be obtained in the liquid fraction with Si/Al ZSM‐5 zeolite, while olefins remain the major fraction with the less acidic amorphous aluminosilicate catalyst.
Vanadium Doped Nickel Phosphide Nanosheets Self‐Assembled Microspheres as a High‐Efficiency Oxygen Evolution Catalyst
Authors: Li Yao , Jiang Xiaoli , Miao Zhuang , Tang Jiaruo , Zheng Qiaoji , Xie Fengyu , Lin Dunmin 
Published: November 2019

AbstractRecently, much attention has been paid to the low‐cost, high‐efficiency and stable non‐precious metal catalysts for oxygen evolution reaction (OER). In this work, vanadium (V)‐doped nickel phosphide (Ni2P) nanosheets self‐assembled microspheres supported on nickel foam (Ni1V1P NSs/NF) were synthesized as a novel OER catalyst by combined processes of hydrothermal method and low‐temperature phosphorization. The synthesized Ni1V1P NSs/NF material shows excellent catalytic activity due to its interconnected three‐dimensional (3D) structure and synergistic effect between nickel and vanadium. When used as a catalyst electrode for OER, the synthesized Ni1V1P NSs/NF exhibits excellent electrocatalytic activity, reaching a current density of 50 mA cm−2 at the low overpotential of 250 mV in 1.0 M KOH. This material also shows superior electrochemical stability with negligible decay of the activity after continual measurement for 15 h at 50 and 100 mA cm−2 in 1.0 M KOH, respectively. This work provides a valuable method to synthesize efficient OER catalysts by doping valence‐variable metal ions and designing distinctive 3D structure.