bluuebunny/crossref_metadata_2025_split huggingface dataset:
Carbon Dots with Dual‐Emissive, Robust, and Aggregation‐Induced Room‐Temperature Phosphorescence Characteristics
Authors: Jiang Kai , Gao Xiaolu , Feng Xiangyu , Wang Yuhui , Li Zhongjun , Lin Hengwei 
Published: November 2019

AbstractCarbon dots (CDs) with dual‐emissive, robust, and aggregation‐induced RTP characteristics are reported for the first time. The TA‐CDs are prepared via hydrothermal treatment of trimellitic acid and exhibit unique white prompt and yellow RTP emissions in solid state under UV excitation (365 nm) on and off, respectively. The yellow RTP emission of TA‐CDs powder should be resulted from the formation of a new excited triplet state due to their aggregation, and the white prompt emission is due to their blue fluorescence and yellow RTP dual‐emissive nature. The RTP emission of TA‐CDs powder was highly stable under grinding, which is very rare amongst traditional pure organic RTP materials. To employ the unique characteristics of TA‐CDs, advanced anti‐counterfeiting and information encryption methodologies (water‐stimuli‐response producing RTP) were preliminarily investigated.
Tunable Thermoelastic Anisotropy in Hybrid Bragg Stacks with Extreme Polymer Confinement
Authors: Wang Zuyuan , Rolle Konrad , Schilling Theresa , Hummel Patrick , Philipp Alexandra , Kopera Bernd A. F. , Lechner Anna M. , Retsch Markus , Breu Josef , Fytas George 
Published: November 2019

AbstractControlling thermomechanical anisotropy is important for emerging heat management applications such as thermal interface and electronic packaging materials. Whereas many studies report on thermal transport in anisotropic nanocomposite materials, a fundamental understanding of the interplay between mechanical and thermal properties is missing, due to the lack of measurements of direction‐dependent mechanical properties. In this work, exceptionally coherent and transparent hybrid Bragg stacks made of strictly alternating mica‐type nanosheets (synthetic hectorite) and polymer layers (polyvinylpyrrolidone) were fabricated at large scale. Distinct from ordinary nanocomposites, these stacks display long‐range periodicity, which is tunable down to angstrom precision. A large thermal transport anisotropy (up to 38) is consequently observed, with the high in‐plane thermal conductivity (up to 5.7 W m−1 K−1) exhibiting an effective medium behavior. The unique hybrid material combined with advanced characterization techniques allows correlating the full elastic tensors to the direction‐dependent thermal conductivities. We, therefore, provide a first analysis on how the direction‐dependent Young's and shear moduli influence the flow of heat.
Carbazole‐Based Tetrapodal Anchor Groups for Gold Surfaces: Synthesis and Conductance Properties
Authors: O'Driscoll Luke J. , Wang Xintai , Jay Michael , Batsanov Andrei S. , Sadeghi Hatef , Lambert Colin J. , Robinson Benjamin J. , Bryce Martin R. 
Published: November 2019

AbstractAs the field of molecular‐scale electronics matures and the prospect of devices incorporating molecular wires becomes more feasible, it is necessary to progress from the simple anchor groups used in fundamental conductance studies to more elaborate anchors designed with device stability in mind. This study presents a series of oligo(phenylene‐ethynylene) wires with one tetrapodal anchor and a phenyl or pyridyl head group. The new anchors are designed to bind strongly to gold surfaces without disrupting the conductance pathway of the wires. Conductive probe atomic force microscopy (cAFM) was used to determine the conductance of self‐assembled monolayers (SAMs) of the wires in Au–SAM–Pt and Au–SAM–graphene junctions, from which the conductance per molecule was derived. For tolane‐type wires, mean conductances per molecule of up to 10−4.37 G0 (Pt) and 10−3.78 G0 (graphene) were measured, despite limited electronic coupling to the Au electrode, demonstrating the potential of this approach. Computational studies of the surface binding geometry and transport properties rationalise and support the experimental results.
Structure and Properties of Violet Phosphorus and Its Phosphorene Exfoliation
Authors: Zhang Lihui , Huang Hongyang , Zhang Bo , Gu Mengyue , Zhao Dan , Zhao Xuewen , Li Longren , Zhou Jun , Wu Kai , Cheng Yonghong , Zhang Jinying 
Published: November 2019

AbstractBlack phosphorene has attracted much attention as a semiconducting two‐dimensional material. Violet phosphorus is another layered semiconducting phosphorus allotrope with unique electronic and optoelectronic properties. However, no confirmed violet crystals or reliable lattice structure of violet phosphorus had been obtained. Now, violet phosphorus single crystals were produced and the lattice structure has been obtained by single‐crystal x‐ray diffraction to be monoclinic with space group of P2/n (13) (a=9.210, b=9.128, c=21.893 Å, β=97.776°). The lattice structure obtained was confirmed to be reliable and stable. The optical band gap of violet phosphorus is around 1.7 eV, which is slightly larger than the calculated value. The thermal decomposition temperature was 52 °C higher than its black phosphorus counterpart, which was assumed to be the most stable form. Violet phosphorene was easily obtained by both mechanical and solution exfoliation under ambient conditions.
Enantioselective Alkynylation of Trifluoromethyl Ketones Catalyzed by Cation‐Binding Salen Nickel Complexes
Authors: Park Dongseong , Jette Carina I. , Kim Jiyun , Jung Woo‐Ok , Lee Yongmin , Park Jongwoo , Kang Seungyoon , Han Min Su , Stoltz Brian M. , Hong Sukwon 
Published: November 2019

AbstractCation‐binding salen nickel catalysts were developed for the enantioselective alkynylation of trifluoromethyl ketones in high yield (up to 99 %) and high enantioselectivity (up to 97 % ee). The reaction proceeds with substoichiometric quantities of base (10–20 mol % KOt‐Bu) and open to air. In the case of trifluoromethyl vinyl ketones, excellent chemo‐selectivity was observed, generating 1,2‐addition products exclusively over 1,4‐addition products. UV‐vis analysis revealed the pendant oligo‐ether group of the catalyst strongly binds to the potassium cation (K+) with 1:1 binding stoichiometry (Ka=6.6×105 m−1).
Photochemical Carbopyridylation of Alkenes UsingN‐Alkenoxypyridinium Salts as Bifunctional Reagents
Authors: Mathi Gangadhar Rao , Jeong Yujin , Moon Yonghoon , Hong Sungwoo 
Published: November 2019

AbstractN‐Alkenoxypyridinium salts have been used as synthons for the umpolung reaction of enolates for the preparation of α‐functionalized carbonyl compounds. In contrast, we found that the photoreduction of N‐alkenoxypyridinium salts generates α‐carbonyl radicals after cleavage of the N−O bond, thereby allowing simultaneous incorporation of α‐keto and pyridyl groups across unactivated alkenes. In the process, the formed α‐carbonyl radicals engage unactivated alkenes to afford alkyl radical intermediates poised for subsequent addition to pyridinium salts, which ultimately affords a variety of γ‐pyridyl ketones under mild reaction conditions. This transformation is characterized by a broad substrate scope and good functional‐group compatibility, and the utility of this transformation was further demonstrated by the late‐stage functionalization of complex biorelevant molecules.
Prospect of Sulfurized Pyrolyzed Poly(acrylonitrile) (S@pPAN) Cathode Materials for Rechargeable Lithium Batteries
Authors: Yang Huijun , Chen Jiahang , Yang Jun , Wang Jiulin 
Published: November 2019

AbstractLithium–sulfur (Li–S) batteries are one of the most promising next‐generation batteries owing to their ultra‐high theoretical energy density and that sulfur is an abundant resource. During the past 20 years, various sulfur materials have been reported. As a molecular‐scale sulfur‐composite cathode, sulfurized pyrolyzed poly(acrylonitrile) (S@pPAN) exhibits several competitive advantages in terms of its electrochemical behavior. Although it was first reported in 2002 S@pPAN is currently attracting increasing attention. In this Minireview, we summarize its molecular model and explore the correlation between its structure and its exceptional electrochemical performance. We classify the modification strategies into three types, including material improvement, binder, and electrolyte screening. Several research and development directions are also suggested.
One‐Step Synthesis of 2,5‐Diaminoimidazoles and Total Synthesis of Methylglyoxal‐Derived Imidazolium Crosslink (MODIC)
Authors: Sabbasani Venkata R. , Wang Kung‐Pern , Streeter Matthew D. , Spiegel David A. 
Published: November 2019

AbstractHere we describe a general method for the synthesis of 2,5‐diaminoimidazoles, which involves a thermal reaction between α‐aminoketones and substituted guanylhydrazines without the need for additives. As one of the few known ways to access the 2,5‐diaminoimidazole motif, our method greatly expands the number of reported diaminoimidazoles and further supports our previous observations that these compounds spontaneously adopt the non‐aromatic 4(H) tautomer. The reaction works successfully on both cyclic and acyclic amino ketone starting materials, as well as a range of substituted guanylhydrazines. Following optimization, the method was applied to the efficient synthesis of the advanced glycation end product (AGE) methylglyoxal‐derived imidazolium crosslink (MODIC). We expect that this method will enable rapid access to a variety of biologically important 2,5‐diaminoimidazole‐containing products.
Negative Charge as a Lens for Concentrating Antiaromaticity: Using a Pentagonal “Defect” and Helicene Strain for Cyclizations
Authors: Zhou Zheng , Kawade Rahul Kisan , Wei Zheng , Kuriakose Febin , Üngör Ökten , Jo Minyoung , Shatruk Michael , Gershoni‐Poranne Renana , Petrukhina Marina A. , Alabugin Igor V. 
Published: November 2019

AbstractIncorporation of a five‐membered ring into a helicene framework disrupts aromatic conjugation and provides a site for selective deprotonation. The deprotonation creates an anionic cyclopentadienyl unit, switches on conjugation, leads to a >200 nm red‐shift in the absorbance spectrum and injects a charge into a helical conjugated π‐system without injecting a spin. Structural consequences of deprotonation were revealed via analysis of a monoanionic helicene co‐crystallized with {K+(18‐crown‐6)(THF)} and {Cs+2(18‐crown‐6)3}. UV/Vis‐monitoring of these systems shows a time‐dependent formation of mono‐ and dianionic species, and the latter was isolated and crystallographically characterized. The ability of the twisted helicene frame to delocalize the negative charge was probed as a perturbation of aromaticity using NICS scans. Relief of strain, avoidance of antiaromaticity, and increase in charge delocalization assist in the additional dehydrogenative ring closures that yield a new planarized decacyclic dianion.
Tandem Use of Optical Sensing and Machine Learning for the Determination of Absolute Configuration, Enantiomeric and Diastereomeric Ratios, and Concentration of Chiral Samples
Authors: De los Santos Zeus A. , MacAvaney Sean , Russell Katina , Wolf Christian 
Published: November 2019

AbstractWe have developed an optical method for accurate concentration, er, and dr analysis of amino alcohols based on a simple mix‐and‐measure workflow that is fully adaptable to multiwell plate technology and microscale analysis. The conversion of the four aminoindanol stereoisomers with salicylaldehyde to the corresponding Schiff base allows analysis of the dr based on a change in the UV maximum at 420 nm that is very different for the homo‐ and heterochiral diastereomers and of the concentration of the sample using a hypsochromic shift of another absorption band around 340 nm that is independent of the analyte stereochemistry. Subsequent in situ formation of CuII assemblies in the absence and presence of base enables quantification of the er values for each diastereomeric pair by CD analysis. Applying a linear programming method and a parameter sweep algorithm, we determined the concentration and relative amounts of each of the four stereoisomers in 20 samples of vastly different stereoisomeric compositions with an averaged absolute percent error of 1.7 %.
Comparison in composite performance after thermooxidative aging of injection molded polyamide 6 with glass fiber, talc, and a sustainable biocarbon filler
Authors: Jubinville Dylan , Abdelwahab Mohamed , Mohanty Amar K. , Misra Manjusri 
Published: November 2019

ABSTRACTDegradation is an unavoidable part of a material's life making it important to both monitor and control the aging behavior of plastics. This study compares thermooxidative degraded composites of a novel bio‐based and sustainable filler, Biocarbon (MBc), against that of traditional and commercially available fillers (glass fiber and talc) used in the automotive industry. The influence of thermooxidative degradation on the composites was studied under accelerated heat aging for 1000 h at 140°C. The mechanical properties of the composites were evaluated using notched Izod impact as well as both tensile and flexural tests. Morphological structure of the composites was investigated using a scanning electron microscopy. Dynamic mechanical analysis and differential scanning calorimetry were used to evaluate the physical transitions both before and after aging. The glass‐filled composites displayed the best performance; while, both the talc and biocarbon composites possessed similar strength and ductility performances. Advantageously, the biocarbon composites experienced an 11% reduction in density as compared to talc‐filled composites with similar weight content. After aging, all composites exhibited reduced tensile and flexural strengths ranging from 5 to 67% partly due to chain scission. Whereas, the modulus of all composites increased with a range of 1–24% due to an annealing effect. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2020,137, 48618.
Amphiphilic PLGA‐PEG‐PLGA triblock copolymer nanogels varying in gelation temperature and modulus for the extended and controlled release of hyaluronic acid
Authors: Osorno Laura L. , Maldonado Daniel E. , Whitener Ricky J. , Brandley Alyssa N. , Yiantsos Alex , Medina Jamie D. R. , Byrne Mark E. 
Published: November 2019

ABSTRACTDifferent compositional parameters of poly(D,L‐lactic‐co‐glycolic acid)‐b‐poly(ethylene glycol) triblock copolymers (PLGA‐PEG) were varied to analyze their effect on gel formation and mechanical properties. Parameters such as hydrophilic/hydrophobic ratio (PLGA/PEG ratio), lactic acid/glycolic acid ratio (LA/GA ratio), PEG molecular weight (PEG Mw), polymer solution concentration, copolymer molecular weight (Mw), and polydispersity index (PDI) were studied in this work. For copolymers with PEG Mw of 1500 Da, gelation temperature (34–37 °C) was affected by D,L‐LA/GA ratio and Mw; while modulus was affected by LA/GA ratio, Mw, and Mn. Based on the parametric study, an injectable, thermoresponsive hyaluronic acid (HA) delivery platform was designed for ocular applications. PLGA‐PEG copolymers with D,L‐LA/GA ratio of 15/1, PLGA/PEG ratio of 2/1, PEG Mw of 1500 Da, and Mw of about 6 KDa gelled at 35 °C, were optically transparent, had a modulus less than 350 Pa and were used for HA release studies. This work also demonstrates, for the first time, an extended and controlled release of HA, beyond 2 weeks, from injectable hydrogels modified with a noncovalent interacting agent, poly(L‐lysine). Smaller PLL chains slowed down the HA release kinetics, while larger PLL chains produced a release profile similar to the nonmodified hydrogels. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48678.
Aramid pulp reinforced hydrogenated nitrile butadiene rubber composites with ionic liquid compatibilizers
Authors: Demétrio da Silva Vinícius , Barros Ítalo Ribeiro de , Conceição Débora K. Silva da , Almeida Kauana Nunes de , Schrekker Henri Stephan , Amico Sandro C. , Jacobi Marly M. 
Published: November 2019

ABSTRACTAlthough carbon black is an effective reinforcement for most rubbers, its replacement by other fillers would be beneficial. Aramid fibers are used in a range of applications in the rubber industry, providing dimensional stability prior to vulcanization and improving the mechanical properties of the elastomeric product. Nevertheless, their relatively inert surface is an obstacle in the exploitation of their full potential. In this work, two ionic liquids were investigated as compatibilizers in the preparation of hydrogenated nitrile butadiene rubber composites with aramid pulp and carbon black fillers. The materials were characterized using swelling, hardness and tensile tests, differential scanning calorimetry, thermal gravimetric analysis, and infrared spectroscopy. The carbon black‐free composite prepared from aramid pulp treated with 1.0 wt% of 1‐carboxymethyl‐3‐methylimidazolium chloride outperformed all other studied materials, presenting a higher modulus at 100% strain (7.31 MPa), while maintaining high strain at break. Thus, ionic liquids were found to potentialize the aramid reinforcement effect in these rubber composites. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2019,137, 48702.
Ertüchtigung seismisch beschädigter Rahmenknoten aus Stahlbeton mittels FRP‐Filamentbündelverbindungen
Authors: Golias Emmanuil , Lindenthal Heiko , Schlüter Franz‐Hermann , Karabinis Athanasios I. 
Published: November 2019

AbstractIn Gebieten mittlerer und hoher seismischer Gefährdung werden in Stahlbetonskelettkonstruktionen bei Erdbebenereignissen häufig die Rahmenknoten (Anschluss Stütze/Riegel) beschädigt und müssen anschließend für eine weitere Nutzung der Konstruktion instand gesetzt werden.Im Folgenden werden ein neues Sanierungsverfahren und experimentelle Untersuchungen hierzu vorgestellt. Prüfkörper mit zuvor erzeugter moderater Vorschädigung werden mit hochfestem Reparaturmörtel und Filamentbündelverbindungen (C‐FRP) im Knotenpunkt Stütze/Riegel verstärkt. Es werden die Versuchsergebnisse eines Prüfkörpers im Maßstab 1:1 im ungeschädigten Zustand (JA1V) sowie im nach Vorschädigung verstärkten Zustand (JA1FXb) ausgewertet und verglichen. Zur Simulation der Erdbebenwirkungen wird dabei zunächst der ungeschädigte Prüfkörper auf dem Prüfstand zyklisch belastet. Anschließend wird derselbe, durch den ersten Versuch vorgeschädigte Prüfkörper mit Filamentbündelverbindungen (C‐FRP) im Knoten und im Unterzugbereich verstärkt und auf dem Prüfstand erneut den identischen zyklischen Belastungen ausgesetzt. Die wesentlichen Messergebnisse beider Versuche werden aufgezeichnet und hinsichtlich Tragfähigkeit, Steifigkeiten und absorbierter Energie (Fähigkeit zur Energiedissipation) miteinander verglichen. Des Weiteren wird die angewendete Sanierungstechnik im Detail vorgestellt.
Novel and de novo mutation of PCDH19 in Girls Clustering Epilepsy
Authors: Yang Li , Liu Jing , Su Quanping , Li Yufen , Yang Xiaofan , Xu Liyun , Tong Lili , Li Baomin 
Published: November 2019

AbstractBackgroundPCDH19 has become the second most relevant gene in epilepsy after SCN1A. Seizures often provoked by fever.MethodsWe screened 152 children with fever‐sensitive epilepsy for gene detection. Their clinical information was followed up.ResultsWe found eight PCDH19 point mutations (four novel and four reported) and one whole gene deletion in 10 female probands (seven sporadic cases and three family cases) who also had cluster seizures. The common clinical features of 16 patients in 10 families included fever‐sensitive and cluster seizures, mainly focal or tonic‐clonic seizures, and absence of status epilepticus, normal intelligence, or mild‐to‐moderate cognitive impairment, the onset age ranges from 5 months to 20 years. Only four patients had multiple or focal transient discharges in interictal EEG. Focal seizures originating in the frontal region were recorded in four patients, two from the parietal region, and one from the occipital region.ConclusionPCDH19 mutation can be inherited or de novo. The clinical spectrum of PCDH19 mutation includes PCDH19 Girls Clustering Epilepsy with or without mental retardation, psychosis, and asymptomatic male. The onset age of PCDH19 Girls Clustering Epilepsy can range from infancy to adulthood. Sisters in the same family may be sensitive to the same antiepileptic drugs. And our report expands the mutation spectrum of PCDH19 Girls Clustering Epilepsy.
Development and pilot evaluation of a personalized decision support intervention for low risk prostate cancer patients
Authors: Belkora Jeffrey , Chan June M. , Cooperberg Matthew R. , Neuhaus John , Stupar Lauren , Weinberg Tia , Broering Jeanette M. , Tenggara Imelda , Cowan Janet E. , Rosenfeld Stan , Kenfield Stacey A. , Van Blarigan Erin L. , Simko Jeffry P. , Witte John , Carroll Peter R. 
Published: November 2019

AbstractObjectivesDevelopment and pilot evaluation of a personalized decision support intervention to help men with early‐stage prostate cancer choose among active surveillance, surgery, and radiation.MethodsWe developed a decision aid featuring long‐term survival and side effects data, based on focus group input and stakeholder endorsement. We trained premedical students to administer the intervention to newly diagnosed men with low‐risk prostate cancer seen at the University of California, San Francisco. Before the intervention, and after the consultation with a urologist, we administered the Decision Quality Instrument for Prostate Cancer (DQI‐PC). We hypothesized increases in two knowledge items from the DQI‐PC: How many men diagnosed with early‐stage prostate cancer will eventually die of prostate cancer? How much would waiting 3 months to make a treatment decision affect chances of survival? Correct answers were: “Most will die of something else” and “A little or not at all.”ResultsThe development phase involved 6 patients, 1 family member, 2 physicians, and 5 other health care providers. In our pilot test, 57 men consented, and 44 received the decision support intervention and completed knowledge surveys at both timepoints. Regarding the two knowledge items of interest, before the intervention, 35/56 (63%) answered both correctly, compared to 36/44 (82%) after the medical consultation (P = .04 by chi‐square test).ConclusionsThe intervention was associated with increased patient knowledge. Data from this pilot have guided the development of a larger scale randomized clinical trial to improve decision quality in men with prostate cancer being treated in community settings.