bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cobalt(II) Porphyrin Catalyzed Cascade Reaction of Pyrrolyl Ketones for Construction of Polysubstituted Pyrrolizidines and Pyrrolizines
Authors: Hao Fei , Reddy Annapureddy Rajasekar , Zhou Cong‐Ying , Che Chi‐Ming 
Published: January 2018

AbstractWe developed an efficient method for the synthesis of polysubstituted 3H‐pyrrolizines and pyrrolizidines via a cobalt(II) porphyrin catalyzed intramolecular cyclopropanation/ring opening cascade reaction of hydrazones derived from pyrrolyl ketones. With CoII(F20TPP) as catalyst, a variety of pyrrolyl ketones underwent condensation, intramolecular cyclopropanation/ring opening cascade reaction and subsequent oxidation or reduction to give 3H‐pyrrolizines or pyrrolizidines in good yields. This Co(II) catalyzed cascade reaction provides a rapid access to polysubstituted 3H‐pyrrolizines and pyrrolizidines from readily accessible starting materials.magnified image
Nonspiro, Fluorene‐Based, Amorphous Hole Transporting Materials for Efficient and Stable Perovskite Solar Cells
Authors: Daškevičiū tė Šarūnė , Sakai Nobuya , Franckevičius Marius , Daškevičienė Marytė , Magomedov Artiom , Jankauskas Vygintas , Snaith Henry J. , Getautis Vytautas 
Published: January 2018

AbstractNovel nonspiro, fluorene‐based, small‐molecule hole transporting materials (HTMs) V1050 and V1061 are designed and synthesized using a facile three‐step synthetic route. The synthesized compounds exhibit amorphous nature with a high glass transition temperature, a good solubility, and decent thermal stability. The planar perovskite solar cells (PSCs) employing V1050 generated an excellent power conversion efficiency of 18.3%, which is comparable to 18.9% obtained with the state‐of‐the‐art Spiro‐OMeTAD. Importantly, the devices based on V1050 and V1061 show better stability compared to devices based on Spiro‐OMeTAD when aged without any encapsulation under uncontrolled humidity conditions (relative humidity around 60%) in the dark and under continuous full sun illumination.
Ultrathin Organic Solar Cells with a Power Conversion Efficiency of Over ≈13.0%, Based on the Spatial Corrugation of the Metal Electrode–Cathode Fabry–Perot Cavity
Authors: In Sungjun , Park Namkyoo 
Published: January 2018

AbstractThe application of nanophotonic structures for organic solar cells (OSCs) is quite popular and successful, and has led to increased optical absorption, better spectral overlap with solar irradiances, and improved charge collection. Significant improvements in the power conversion efficiency (PCE) have also been reported, exceeding 11%. Nonetheless, with the given material properties of OSCs with low optical absorption, narrow spectrum, short transport length of carriers, and nonuniform photocarrier generations resulting from the nanophotonic structure, the PCE of single‐junction OSCs has been stagnant over the past few years, at a barrier of 12%. Here, an ultrathin inverted OSC structure with the highest efficiency of ≈13.0%, while being made from widely used organic materials, is demonstrated. By introducing a smooth spatial corrugation to the vertical plasmonic cavity enclosing the active layer, in‐plane propagation modes and hybridized Fabry–Perot cavity modes inside the corrugated cavity are derived to achieve an ultralow Q, uniform coverage of optical absorption, in addition to uniform photocarrier generation and transport. As the first demonstration of ultra‐broadband absorption with the introduction of spatial corrugation to the ultrathin metal film electrode–cathode Fabry–Perot cavity, future applications of the same concept in other light‐harvesting devices utilizing different materials and structures are expected.
La2/3Sr1/3VO3 Thin Films: A New p‐Type Transparent Conducting Oxide with Very High Figure of Merit
Authors: Hu Ling , Wei Renhuai , Yan Jian , Wang Dong , Tang Xianwu , Luo Xuan , Song Wenhai , Dai Jianmin , Zhu Xuebin , Zhang Changjin , Sun Yuping 
Published: January 2018

AbstractTransparent conducting oxides (TCOs) are a unique series of materials combining electrical conductivity with optical transparency. Most of the commercially available TCOs are of the n‐type. The performance of p‐type TCOs, however, is far behind their n‐type TCO counterparts primarily due to the doping bottleneck and low hole mobility. Herein, a Mott–Hubbard insulator of LaVO3 is proposed as the starting point for exploring p‐type TCOs. Substitution of La3+ by Sr2+ can introduce high hole carrier concentration at the top of the valence band to overcome the doping bottleneck. Combining a modest carrier mobility with weak absorption in the visible region, La1‐xSrxVO3 compounds can serve as new p‐type TCOs and exhibit good balance of the tradeoffs between electrical conductivity and optical transparency. It is demonstrated that La2/3Sr1/3VO3 thin films exhibit a high conductivity of 742.3–872.3 S cm−1 at room temperature and a high transmission of 53.9–70.1% in the visible region, which leads to the highest figure of merit among p‐type TCOs so far.
Decoupling Hydrogen and Oxygen Production in Acidic Water Electrolysis Using a Polytriphenylamine‐Based Battery Electrode
Authors: Ma Yuanyuan , Dong Xiaoli , Wang Yonggang , Xia Yongyao 
Published: January 2018

AbstractHydrogen production through water splitting is considered a promising approach for solar energy harvesting. However, the variable and intermittent nature of solar energy and the co‐production of H2 and O2 significantly reduce the flexibility of this approach, increasing the costs of its use in practical applications. Herein, using the reversible n‐type doping/de‐doping reaction of the solid‐state polytriphenylamine‐based battery electrode, we decouple the H2 and O2 production in acid water electrolysis. In this architecture, the H2 and O2 production occur at different times, which eliminates the issue of gas mixing and adapts to the variable and intermittent nature of solar energy, facilitating the conversion of solar energy to hydrogen (STH). Furthermore, for the first time, we demonstrate a membrane‐free solar water splitting through commercial photovoltaics and the decoupled acid water electrolysis, which potentially paves the way for a new approach for solar water splitting.
Total Synthesis and Stereochemical Revision of Iriomoteolide‐2a
Authors: Sakamoto Keita , Hakamata Akihiro , Tsuda Masashi , Fuwa Haruhiko 
Published: January 2018

AbstractTotal syntheses of the proposed and correct structures of iriomoteolide‐2a, a cytotoxic marine macrolide natural product with an unusual 23‐membered macrolactone skeleton, have been accomplished for the first time. The synthesis of the correct structure involves an asymmetric epoxidation/diepoxide cyclization cascade for the construction of the bis(tetrahydrofuran) moiety, a Suzuki–Miyaura coupling for the fragment assembly, and a ring‐closing metathesis for the closure of the macrocyclic backbone. In addition, the original stereochemical assignment of iriomoteolide‐2a was revised.
Evolution of surface functional groups of coal char during coal combustion under O2/CO2 atmospheres
Authors: Yan Dawei , Gu Mingyan , Lin Yuyu , Chen Ping , He Xianhui 
Published: January 2018

AbstractIn this study, quantitative analysis was conducted to study the changes in characteristics of surface functional groups of coal char under O2/CO2 atmospheres using Fourier transform infrared analysis. A drop tube furnace was explored. Besides, the effect of the oxygen‐containing functional group on the generation characteristics of NO emission was also investigated. The results showed that CH2/CH3 is highly influenced by the process and atmosphere of coal combustion. The burning of coal increases the contents of aromatic hydrogen and aromaticity on the surface of coal char particles, and it decreases the content of lipid hydrogen. The oxygen concentration exhibits a significant effect on the oxygen‐containing functional groups in coal char, which promotes the reduction reaction of NO. There is an optimum oxygen concentration of 30% that creates the best NO reduction effect caused by the oxygen‐containing functional groups.
Advanced architectures in the design of responsive polymers for cancer nanomedicine
Authors: Wagner Angela M. , Spencer David S. , Peppas Nicholas A. 
Published: January 2018

ABSTRACTIn recent decades, nanoparticles have shown significant promise as an oncology treatment modality. Responsive polymers represent a promising class of nanoparticles that can trigger delivery through the exploitation of a specific stimuli. Response to a stimulus is one of the most basic processes found in living systems. As such, the desire to engineer dynamic and functional materials is becoming more prevalent in an effort to achieve precise control over our environment. The combination of controlled radical polymerization and high yielding chemistry strategies provide an excellent basis for the development of the next generation of drug delivery systems. The versatility of polymer chemistries available enables the synthesis of increasingly complex architectures with enhanced delivery specificity and control over the desired properties to interface with biological systems. This tutorial review highlights recent developments in polymer‐based approaches to internally responsive nanoparticles for oncology. Presented are concise overviews of the current challenges and opportunities in cancer nanomedicine, common polymer‐based architectures, and the basis for internally triggered stimuli–response relationships commonly employed in oncology applications. Examples of the chemistry used in the design of environmentally labile nanomaterials are discussed, and we outline recent advances in creating advanced bioresponsive drug delivery architectures. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46154.
Synthesis of a polymeric sensor containing an occluded pyrylium salt and its application in the colorimetric detection of trimethylamine vapors
Authors: Bustamante Fonseca Saúl E. , Rivas Bernabé L. , García Pérez José M. , Vallejos Calzada Saúl , García Félix 
Published: January 2018

ABSTRACTA dense membrane (MS) based on vinyl polymers and containing a pyrylium salt [2,6‐diphenyl‐4(p‐methacryloyloxy)phenylpyryliumtetrafluoroborate] was prepared. The MS has hydrophilic and sensory properties that make it a good material for the selective colorimetric detection of trimethylamine (TMA) vapors, a biogenic amine of great importance in food safety. The polymeric sensor changes from yellow to an intense pink color with increasing concentrations of TMA. The material could be reused in the presence of HCl vapors for at least 10 times. The detection and quantification limits were determined by ultraviolet–visible absorption spectroscopy (4.42 and 13.40 ppm, respectively) and by the RGB parameters of digital color (3.37 and10.22 ppm, respectively). © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46185.
Synthesis of high‐solid‐content, acrylic pressure‐sensitive adhesives by solvent polymerization
Authors: Kuo Chung‐Feng Jeffrey , Chen Jiong‐Bo 
Published: January 2018

ABSTRACTIn this study, we prepared high solid content (SC), solvent‐based, acrylic pressure‐sensitive adhesives (PSAs) with n‐dodecyl mercaptan as a chain‐transfer agent (CTA) and studied the crosslinking reactions between the crosslinker and the acrylic PSAs. Acrylic PSAs were prepared from 2‐ethyl hexyl acrylate, acrylic acid (AA), and 2‐azobisisobutyronitrile with a solution polymerization process. The results show AA resulted in an effective molecular weight in the acrylic PSAs, as it improved the hydrophilicity with increasing peel strength of the acrylic PSAs. As for the high SC, the molecular weight and system viscosity decreased through the addition of CTA. At a constant AA amount, the addition of CTA decreased the molecular weight and increased the hydrophobicity of the acrylic PSAs; this decreased the peel strength of the acrylic PSAs on the glass. Furthermore, the addition of CTA decreased the molecular weight and improved the acrylic PSAs' surface morphologies and optical properties. The acrylic PSAs produced in this study could meet production needs. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46257.
Tuning of Thermoresponsivity of a Poly(2‐alkyl‐2‐oxazoline) Block Copolymer by Interaction with Surface‐Active and Chaotropic Metallacarborane Anion
Authors: Ďorďovič Vladimír , Verbraeken Bart , Hogenboom Richard , Kereïche Sami , Matějíček Pavel , Uchman Mariusz 
Published: January 2018

AbstractThermoresponsive nanoparticles based on the interaction of metallacarboranes, bulky chaotropic and surface‐active anions, and poly(2‐alkyl‐2‐oxazoline) block copolymers were prepared. Recently, the great potential of metallacarboranes have been recognized in biomedicine and many delivery nanosystems have been proposed. However, none of them are thermoresponsive. Therefore, a thermoresponsive block copolymer, poly(2‐methyl‐2‐oxazoline)‐block‐poly(2‐n‐propyl‐2‐oxazoline) (PMeOx–PPrOx), was synthesized to encapsulate metallacarboranes. Light scattering, NMR spectroscopy, isothermal titration calorimetry, and cryogenic TEM were used to characterize all solutions of the formed nanoparticles. The cloud‐point temperature (TCP) of the block copolymer was observed at 30 °C and polymeric micelles formed above this temperature. Cobalt bis(dicarbollide) anion (COSAN) interacts with both polymeric segments. Depending on the COSAN concentration, this affinity influenced the phase transition of the thermoresponsive PPrOx block. The TCP shifted to lower values at a lower COSAN content. At higher COSAN concentrations, the hybrid nanoparticles are fragmented into relatively small pieces. This system is also thermoresponsive, whereby an increase in temperature leads to higher polymer mobility and COSAN release.
A Spin‐Active, Electrochromic, Solvent‐Free Molecular Liquid Based on Double‐Decker Lutetium Phthalocyanine Bearing Long Branched Alkyl Chains
Authors: Zielinska Agnieszka , Takai Atsuro , Sakurai Hiroya , Saeki Akinori , Leonowicz Marcin , Nakanishi Takashi 
Published: January 2018

AbstractSynthesis and characterization of a novel, multifunctional, solvent‐free room‐temperature liquid based on alkylated double‐decker lutetium(III) phthalocyanine (Pc2Lu) are described. Lowering of the melting point and viscosity of intrinsically solid Pc2Lu compounds has been achieved through the attachment of flexible, bulky, and long branched‐alkyl chains, that is, thio‐2‐octyldodecyl, to the periphery of the Pc2Lu unit. The embedded Pc2Lu unit maintains its inherent molecular functions, such as spin‐active nature and electrochromic behavior in the liquid state. Comparison of the properties with a solid‐like Pc2Lu derivative, functionalized with shorter alkyl chains, that is, thio‐2‐ethylhexyl, underlines the importance of the hampering effect on the π–π interactions of neighboring Pc2Lu molecules by bulkier and longer branched‐alkyl chains. This study could possibly pave the way for novel multifunctional liquids whose spin‐activities are associated with their rheological or optoelectronic properties.
Application of hydrocarbon and perfluorocarbon oxygen vectors to enhance heterologous production of hyaluronic acid in engineered Bacillus subtilis
Authors: Westbrook Adam W. , Ren Xiang , Moo‐Young Murray , Chou C. Perry 
Published: January 2018

AbstractIn microbial cultivations for hyaluronic acid (HA) production, oxygen can be a limiting substrate due to its poor solubility in aqueous medium and the substantial increase in culture viscosity at relatively low HA titers. Shear stress due to the high agitation and aeration rates required to overcome oxygen limitation may reduce the quality (i.e., molecular weight) of HA, and production costs associated with power consumption and supplemental oxygen may be excessive. Here, we report the application of oxygen vectors to the heterologous production of HA in engineered Bacillus subtilis, leading to significantly improved culture performance. We first derived an improved HA‐producing strain of B. subtilis through engineering of the promoter driving coexpression of seHas and tuaD, leading to high‐level HA production. Out of seven potential oxygen vectors evaluated in a preliminary screening, significant improvements to the HA titer and/or cell density were observed in cultures containing n‐heptane, n‐hexadecane, perfluoromethyldecalin, and perfluoro‐1,3‐dimethylcyclohexane. Adjustments to the vector concentration, timing of vector addition, and the agitation rate resulted in further enhancements, with the HA titer reaching up to 4.5 g/L after only 10 hr cultivation. Moreover, our results indicate that certain vectors may alter the functional expression of Class I hyaluronan synthase (HAS) in B. subtilis, and that higher shear rates may drive more carbon flux through the HA biosynthetic pathway without negatively affecting the MW. Our study demonstrates the efficacy of oxygen vectors to enhance heterologous HA production in B. subtilis, and provides valuable insight for future bioprocess development in microbial HA production.
The characteristics of cognitive impairment in subjective chronic tinnitus
Authors: Wang Yi , Zhang Jian‐Ning , Hu Wei , Li Ji‐Jun , Zhou Jia‐Xuan , Zhang Jian‐Ping , Shi Guo‐Feng , He Ping , Li Zai‐Wang , Li Ming 
Published: January 2018

AbstractIntroductionSubjective chronic tinnitus is a common medical syndrome with a high frequency of cognitive impairment; however, the characteristics of cognitive impairment in chronic tinnitus are poorly understood. Investigating the scope of cognitive impairment across the severity spectrum of tinnitus patients may shed light on the issue.MethodsA consecutive series of 207 subjective chronic tinnitus patients were classified into mild tinnitus group (n = 95) and severe tinnitus group (n = 112) by THI score (the cutoff THI scores were 37/38). These patients were assessed using the Cognitive Abilities Screening Instrument (CASI) and P300 event‐related potential.ResultsAlthough pure tone averages were not different between mild or severe tinnitus patients, severe tinnitus patients scored lower on the CASI assessment as well as almost all subdomains of CASI, particularly in items such as “short‐term memory,” “concentration or mental manipulation,” “orientation,” “abstraction and judgment,” “language abilities,” and “visual construction.” Furthermore, compared to mild tinnitus patients, severe tinnitus patients exhibited longer N2 and P3 latencies. Finally, a correlation analysis revealed that tinnitus severity was negatively correlated with CASI score and positively correlated with N2 and P3 latencies.ConclusionsThis study reveals that tinnitus patients on the severe end of the spectrum may be at risk for serious cognitive deficits, which may not be a secondary response to disease manifestations but a primary feature of the underlying disease.
Object‐oriented modeling approach of universal education software
Authors: Petković Dalibor , Jovic Srdjan , Golubovic Zoran 
Published: January 2018

AbstractSince learning process could be very challenging task for scholars in this article an attempt to analyze and model a universal education software (UES) was made. The software was modeled from beginning of the life cycle by object‐orientated modeling approach. In order to visually represent any research problem unified modeling language is the most appropriate and efficient tool. In this paper UES was modeled by unified modeling language diagrams which could lead to better development and understanding of the behavior and structure of the software. Modeling by unified modeling language is a new way of thinking about systems and the development process which involved object modeling. The main concept of the object modeling is the object identification within the system environment, and the relationships and interactions between the objects.
Spoon nails: still seen in today's world
Authors: Moiz Bushra 
Published: January 2018

Key Clinical MessageKoilonychia is a nail abnormality characterized by thin, brittle, and spoon‐shaped nails. It is frequently observed in chronic iron deficiency secondary to malnutrition, chronic blood loss, or malabsorption. It may also be idiopathic or related to occupation and rare systemic disorders. Presence of koilonychia should prompt investigations for iron deficiency.
Interfacial Generation of a Carbanion: The Key Step of PTC Reaction Directly Observed by Second Harmonic Generation
Authors: Hamkalo Michal , Fita Piotr , Fedorynski Michal , Makosza Mieczyslaw 
Published: January 2018

AbstractWe present the first unambiguous evidence of the interfacial mechanism of phase‐transfer catalysis (PTC) by direct observation of the formation of carbanions in the interfacial region between the aqueous and the organic phase by using a surface‐sensitive spectroscopic method known as second harmonic generation (SHG). Ion exchange of carbanions adsorbed at the surface after addition of lipophilic tetraalkylammonium salts (TAA) to organic phase and transport of the lipophilic ion‐pairs to the organic phase is observed. Results allow for the formulation of a more detailed mechanism of PTC.
Phenylene Bridged Cyclic Azaacenes: Dimers and Trimers
Authors: Hahn Sebastian , Koser Silke , Hodecker Manuel , Seete Pascal , Rominger Frank , Miljanić Ognjen Š. , Dreuw Andreas , Bunz Uwe H. F. 
Published: January 2018

AbstractThe synthesis and characterization of novel macrocyclic, phenylene‐bridged azaacenes is reported. These species were obtained either by a conventional benzoin– diamine condensation, as shown for the case of the cyclotrimers, in which the azaacene units are separated by meta‐connected phenylene bridges, or by a Buchwald–Hartwig‐type Pd‐catalyzed coupling, which employs 1,2,5,6‐tetrabromodibenzocyclooctatetraene as the substrate and bis‐TIPS‐ethynylated diaminobenzene, ‐naphthalene or ‐anthracene as the coupling partner to give the double coupling products azaacene‐annulated dibenzocyclooctatetraenes in moderate yields. The macrocycles show strong emission and light emitting diodes have been built with brightnesses exceeding 1600 cd m−2. We evaluated the optical and electronic properties and the solid‐state structures of the molecules and discuss their properties through comparison with their linear and tetrameric N‐heteroacene counterparts.
Single Ion Magnets from 3d to 5f: Developments and Strategies
Authors: Feng Min , Tong Ming‐Liang 
Published: January 2018

AbstractSingle‐ion magnets (SIMs), exhibiting slow magnetization relaxation in the absence of the magnetic field, originate from their single spin‐carrier centre. In pursuit of high‐performance magnetic properties, such as high spin‐reversal barrier and high blocking temperature, various metal centres were investigated to establish SIMs, including 3d and 5d transition metal ions, 4f lanthanide ions, and 5f actinide ions, which possess unique zero‐field splitting and magnetic properties. Therefore, proper ligand field is of great importance to different types of metals. In the given great breakthroughs since the first SIM, [Pc2Tb]− (Pc=dianion of phthalocyanine), was reported, strategies of ligand field design have emerged. In this review, the developments of SIMs with different metal centres are summarized, as well as the possible strategies.