bluuebunny/crossref_metadata_2025_split huggingface dataset:
The SI Unit Candela
Authors: Sperling Armin , Kück Stefan 
Published: January 2019

AbstractThe history of photometry, the measurement of light—and thus also the root of the basic unit for the luminous intensity, goes back to the seventeenth century. The theoretical foundations are provided by Johann H. Lambert in his treatise on photometry around 1760. With industrialization in the nineteenth century, there is an increasing demand for stable reference light sources for the measurement of light and for an reliable definition of the unit for light. But it is not until the middle of the twentieth century that the basic prerequisites had been created to use a common, internationally recognized unit, the Candela, as a measure of the visible light. The following article describes the basics and the boundary conditions that arise for the unit candela from the revision of the SI.
All‐Optical Transmission Modulation Due to Inelastic Interactions of Ultrashort Pulses in a Disordered Resonant Medium
Authors: Novitsky Denis V. , Shalin Alexander S. 
Published: January 2019

AbstractRandom resonant media being one of the possible realizations of disordered metamaterials open a room of opportunities for achieving new fundamental effects and designing advanced nanophotonic devices. Strongly nonlinear optical properties of such media attract ever increasing attention nowadays from both theoretical and experimental points of view. Hereinafter, the case of the photonic‐crystal‐like structure with a randomly varying light–matter coupling provided by the random density of quantum particles is considered. Using numerical solution of the Maxwell–Bloch equations, the effects of the pulse collisions in the medium are studied. It is shown that disorder enables the qualitative changes of the system's response for co‐propagating pulses, whereas this is not the case for the counter‐propagating ones. The scheme for an all‐optical transmission modulation due to the disorder‐induced inelasticity of collisions of co‐propagating pulses is proposed. The ability of precise tuning the modulation via the inter‐pulse distance and background refractive index adjustment is revealed. This novel approach for light control can be utilized for some high demand applications, such as modulation and switching of a pulsed radiation.
Halogenbedingte Oberflächenbindung steuert die selektive Alkanfunktionalisierung zu Olefinen
Authors: Zichittella Guido , Scharfe Matthias , Puértolas Begoña , Paunović Vladimir , Hemberger Patrick , Bodi Andras , Szentmiklósi László , López Núria , Pérez‐Ramírez Javier 
Published: January 2019

AbstractDie Produktzusammensetzung der direkten Alkanfunktionalisierung durch Oxychlorierung hängt stark von dem verwendeten Halogen ab. Wir zeigen, dass die überragende Olefinselektivität über Eisenphosphatkatalysatoren in Oxychlorierungen eine Konsequenz einer oberflächengebundenen Reaktion ist. Im Unterschied dazu folgt die Alkanaktivierung bei der Oxybromierung einer Radikalkettenreaktion in der Gasphase, wobei ein Gemisch aus Alkylbromid, Cracking‐ und Verbrennungsprodukten entsteht. Die Katalysatoroberflächenchlorierung und die Identifikation von Gasphasenradikalen werden unter Operando‐Bedingungen durch Einsatz verschiedener Methoden mit der katalytischen Leistung korreliert, der es erlaubt, kinetische Untersuchungen mit fortschrittlichen Charakterisierungstechniken, z. B. Prompt‐Gamma‐Aktivierungsanalyse und Photoelektronen‐Photoion‐Koinzidenzspektroskopie, zu vereinen. Die gleichzeitige Erklärung der Gasphasen‐ und Oberflächenanteile durch Dichtefunktionaltheorie zeigt, dass die molekularen Auswirkungen von Chlor entscheidend für die starken Selektivitätsunterschiede sind. Diese Ergebnisse liefern eine Strategie, die es ermöglicht, ein detailliertes mechanistisches Bild eines komplexen Reaktionsnetzwerks zu zeichnen.
A Light‐Activated Polymer Composite Enables On‐Demand Photocontrolled Motion: Transportation at the Liquid/Air Interface
Authors: Ma Shudeng , Li Xiao , Huang Shuai , Hu Jing , Yu Haifeng 
Published: January 2019

AbstractSwimmers at liquid/air interfaces have drawn enormous attention because of their potential applications. Described herein is one novel light‐driven swimmer based on a bimorph composite structure of a photoresponsive liquid‐crystalline polymer network and a commercially available polyimide (Kapton). The motion of the swimmer can be controlled by photoirradiation. The bilayer‐structured film shows quickly photoinduced bending towards the Kapton side upon exposure to UV light, and recovers immediately after removal of light. When placed on a liquid surface, the swimmer propels itself continually though rhythmic beating the liquid like a dolphin moving forward with its tail fin. Besides, light‐powered rotation of the swimmer is successfully achieved by simply changing the length‐width ratio and the irradiation site, mimicking the function of a dolphin's pectoral fin. Combining the forward movement and rotation motion together, on‐demand directional control of the photo‐driven swimmer can be readily obtained at room temperature, showing promise for miniaturized units for transportation.
Synthesis of Plasmonic Group‐4 Nitride Nanocrystals by Solid‐State Metathesis
Authors: Karaballi Reem A. , Humagain Govinda , Fleischman Benjamin R. A. , Dasog Mita 
Published: January 2019

AbstractCeramic nanoparticles that exhibit a plasmonic response are promising next‐generation photonic materials. In this contribution, a solid‐state metathesis method has been reported for the synthesis of Group 4 nitride (TiN, ZrN, and HfN) nanocrystals. A high‐temperature (1000 °C) reaction between Group 4 metal oxide (TiO2, ZrO2, and HfO2) nanoparticles and magnesium nitride powder yielded nitride nanocrystals that were dispersible in water. A localized surface plasmonic resonance was observed in the near‐infrared region for TiN and in the visible region of light for ZrN and HfN nanocrystals. The frequency of the plasmon resonance was dependent on the refractive index of the solvent and the nanocrystal size.
Thermal decomposition kinetics of dynamically vulcanized polyamide 6–acrylonitrile butadiene rubber–halloysite nanotube nanocomposites
Authors: Paran Seyed Mohammad Reza , Vahabi Henri , Jouyandeh Maryam , Ducos Franck , Formela Krzysztof , Saeb Mohammad Reza 
Published: January 2019

ABSTRACTThermally stable thermoplastic elastomer nanocomposites based on polyamide 6 (PA6), acrylonitrile butadiene rubber (NBR), and halloysite nanotubes (HNTs) were dynamically vulcanized, and their nonisothermal decomposition kinetics were examined. The Friedman, Kissinger–Akahira–Sunose (KAS), Ozawa–Wall–Flynn (FWO), and modified Coats–Redfern (m‐CR) isoconversional models were used to obtain information about the kinetics of the thermal decomposition of PA6–NBR–HNTs in terms of the activation energy per partial mass loss monitored through thermogravimetric analyses performed at different heating rates. An erratic trend was due to the Friedman model, especially for systems having higher HNT loadings, whereas the KAS, FWO, and m‐CR models revealed very similar meaningful thermal decomposition kinetics. A relatively high activation energy corroborating a reliable thermal stability was obtained by the addition of HNTs to PA6–NBR, and the resistance against decomposition was higher for systems containing more HNT. This signified the role of the HNTs as thermal stability modifiers. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47483.
Phosphorylated cardanol prepolymer‐grafted carboxylated styrene–butadiene rubber for better processing with enhancing silica filler dispersion
Authors: Prabhavale Onkar , Mahata Denial , Nando Golok B. 
Published: January 2019

ABSTRACTCardanol is a byproduct of cashew industry of semiforest origin. It is cheap and available in humongous amount and acts as a multifunctional additive in rubber compounds. It can be oligomerized with orthophosphoric acid to make phosphorylated cardanol prepolymer (PCP). Hence, cardanol has been chemically grafted on to the backbone chain of carboxylated styrene–butadiene rubber (XSBR) by employing melt grafting technique in presence of peroxide initiator to include multifunctional properties. The PCP‐grafted XSBR (PCP‐g‐XSBR) was characterized by using Fourier transform infrared spectroscopy and 1H‐NMR techniques and optimize the grafting conditions such as percent of grafting and grafting efficiency by using Taguchi methodology. PCP‐g‐XSBR was compounded with silica filler for a comparative study in terms of processing behavior with XSBR. The cure characteristics such as the cure rate and the optimum cure time of the unfilled PCP‐g‐XSBR compounds were determined by oscillating disc rheometer. The thermal analysis of PCP‐g‐XSBR vulcanizate exhibits slightly better thermal stability as well as plasticization effect. Morphological behaviors also display the less cracked and filled fracture surfaces with better filler dispersion in PCP‐g‐XSBR vulcanizate. The mechanical properties of the compounded PCP‐g‐XSBR vulcanizates also improve compare to XSBR vulcanizates. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47528.
Isoselective Ring‐Opening Polymerization of rac‐Lactide Catalyzed by Sodium/potassium Tetradentate Aminobisphenolate Ion‐paired Complexes
Authors: Li Xinlei , Jia Zhaowei , Pan Xiaobo , Wu Jincai 
Published: January 2019

AbstractTwo sodium/potassium tetradentate aminobisphenolate ion‐paired complexes were synthesized and structurally characterized. These ion‐paired complexes are efficient catalysts for the ring‐opening polymerization of rac‐lactide (rac‐LA) in the presence of 5 equivalents BnOH as an initiator and the side reaction of epimerization can be suppressed well at low temperatures. The polymerizations are controllable, affording polylactides with desirable molecular weights and narrow molecular weight distributions; the highest molecular weight can reach 50.1 kg mol−1 in this system, and a best isoselectivity of Pm=0.82 was achieved. Such polymerizations have rarely been reported for isoselective sodium/potassium complexes without crown ether as an auxiliary ligand. The solid structures suggest that BnOH can be activated by an interaction with the anion of sodium/potassium complex via a hydrogen bond and that the monomer is activated by coordination to sodium/potassium ion.
Development of a novel LC–MS/MS method for detection and quantification of tramadol hydrochloride in presence of some mislabeled drugs: Application to counterfeit study
Authors: Abdel‐Megied Ahmed M. , Badr El‐din Khalid M. 
Published: January 2019

AbstractCounterfeiting of pharmaceuticals has become a serious problem all over the world, particularly in developing countries. In the present work, a highly sensitive LC–MS/MS method was developed for simultaneous determination of tramadol hydrochloride in the presence of some suspected mislabeled drugs such as alprazolam, diazepam, chlorpheniramine maleate, diphenylhydramine and paracetamol. The prepared samples were analyzed on an API 4000 mass spectrometer using an Eclipse C18 column (3.5 μm, 4.6 × 100 mm). The mobile phase consisting of 0.01% formic acid, acetonitrile and methanol (60:20:20 v/v/v) was pumped with an isocratic elution at a flow rate of 0.7 mL min−1. The detection was achieved on a triple quadruple tandem mass spectrometer in multiple reaction monitoring mode. The proposed method was successfully validated according to International Conference on Harmonization guidelines with respect to accuracy, precision, linearity, limit of detection and limit of quantitation. The calibration linear range for tramadol hydrochloride, alprazolam, diazepam, chlorpheniramine maleate, diphenylhydramine and paracetamol was 5–500 ng mL−1. The results revealed that the applied method is promising for the differentiation of genuine tramadol tablets from counterfeit ones without prior separation.
Biomimetic Carbohydrate‐Binding Agents (CBAs): Binding Affinities and Biological Activities
Authors: Francesconi Oscar , Roelens Stefano 
Published: January 2019

AbstractMimicking nature in carbohydrate recognition—that is, by using noncovalent interactions exclusively—is a hot topic that has attracted the interest of many scientists in the last 30 years. Carbohydrates are challenging ligands of high biological relevance, playing central roles in several physiological and pathological processes. Carbohydrate‐binding agents (CBAs) of proteic nature, such as lectins, have been extensively used in glycobiology to target carbohydrates, but intrinsic drawbacks conferred on them by their proteic nature limit their therapeutic development. Biomimetic CBAs, artificial small molecules designed for molecular recognition of carbohydrates through noncovalent interactions, have been shown to be effective alternatives in recognising carbohydrates in physiological media, opening the way to biological applications. Herein, we describe the recent achievements in this continually developing field, focusing on those biomimetic CBAs for which biological investigations have been carried out.
Kinetics and Heat Exchanger Design for Catalytic Ortho‐Para Hydrogen Conversion during Liquefaction
Authors: Donaubauer Philipp J. , Cardella Umberto , Decker Lutz , Klein Harald 
Published: January 2019

AbstractA major challenge for hydrogen liquefaction is the required catalytic ortho‐para hydrogen conversion. Efficient liquefaction plants use catalyst‐filled plate‐fin heat exchangers for the conversion. Kinetics of the allotropic reaction are determined using raw literature data on common first‐order and a Langmuir‐Hinshelwood kinetics, including temperature and molar concentration dependencies. Evaluation and comparison of the obtained kinetics results in the first‐order approach as the most stable model. A one‐dimensional continuum reactor model of the counterflow‐cooled, catalyst‐filled plate‐fin heat exchanger is developed and tested combining correlations for heat, mass, and momentum transfer as well as a state‐of‐the‐art equation‐of‐state.
Modular‐Based Simulation of Single Process Units
Authors: Dosta Maksym 
Published: January 2019

AbstractA novel simulation strategy for the modular‐based calculation of models describing single unit operations is proposed. It is based on the functional decomposition of the model with further application of the waveform relaxation approach for data exchange and convergence analysis. Compared to convenient simultaneous calculation of units, the proposed approach leads to higher flexibility during model creation and allow simultaneous usage of several solvers and simulation methods. To illustrate the usability of the developed strategy and analyze its efficiency it has been applied for modeling of a fluidized‐bed spray granulator. Based on the functional decomposition, the granulator model has been decomposed into six separate submodels connected with information streams for data exchange.
Enhanced Light‐Driven Hydrogen‐Production Activity Induced by Accelerated Interfacial Charge Transfer in Donor–Acceptor Conjugated Polymers/TiO2 Hybrid
Authors: Chen Bo , Wang Xuepeng , Dong Wenbo , Zhang Xiaohu , Rao Li , Chen Hao , Huang Dekang , Xiang Yonggang 
Published: January 2019

AbstractDonor–acceptor (D–A) conjugated polymers have proved to be desired candidates to couple with inorganic semiconductors for enhanced photocatalytic activity. Herein, the matched energy levels between polymer BFB and TiO2 make them form BFB‐TiO2 composites with moderate photocatalytic H2 evolution rate (HER). To further enhance the interfacial interaction, BFB was modified with a carboxylic acid end group, which reacted with surface OH of TiO2 to form an ester bond. As a result, the functionalized BFBA‐TiO2 composites exhibited superior photocatalytic activity. Especially, HER of 4 % BFBA‐TiO2 can reach up to 228.2 μmol h−1 under visible light irradiation (λ>420 nm), which is about 2.02 times higher than that of BFB‐TiO2. The enhanced photocatalytic activity originated from the formed ester bond between polymer and TiO2, and photogenerated electrons injection from lowest unoccupied molecular orbital (LUMO) of the exited polymer to conduction band of TiO2 were accelerated. Therefore, based on an intermolecular interaction mechanism, more suitable D–A conjugated polymers with anchoring groups could be designed to couple with other semiconductors for enhancing photocatalytic activity.
Protein fractionation of Moringa oleifera Lam. seeds and functionalization with magnetic particles for the treatment of reactive black 5 solution
Authors: Reck Isabela Maria , Baptista Aline Takaoka Alves , Paixão Rebecca Manesco , Bergamasco Rosângela , Vieira Marcelo Fernandes , Vieira Angélica Marquetotti Salcedo 
Published: January 2019

AbstractIndustrial effluents are sewage from industrial processes, such as polluted cooling waters and waters used for cleaning. It is extremely important that these contaminated waters undergo treatment to allow for water reuse or safe disposal, without damage to the environment. In the present work, the efficacy of coagulating/flocculating aqueous solutions containing reactive black 5 (RB5) dye was evaluated using protein fractions derived from Moringa oleifera seeds (albumin and globulin) as natural coagulants functionalized with iron oxide magnetic nanoparticles. The application of a magnetic field during sedimentation allowed for faster settlement of the dye particles and their separation. Variations in parameters such as the protein concentration, nanoparticle concentration, solution pH, dye concentration, and the presence or absence of an alkalizing agent were assessed. Moreover, the sedimentation time was analyzed with and without the magnetic field and with the reuse of iron oxide nanoparticles. The functionalized magnetic coagulants were able to remove more than 90 % of RB5 dye within 5 min of sedimentation.
Outcome after surgical treatment of dermatofibrosarcoma protuberans: Is clinical follow‐up always indicated?
Authors: Huis in ‘t Veld Eva A. , van Coevorden Frits , Grünhagen Dirk J. , Smith Myles J. , van Akkooi Alexander C. J. , Wouters Michel W. J. M. , Hayes Andrew J. , Verhoef Cornelis , Strauss Dirk C. , van Houdt Winan J. 
Published: January 2019

BackgroundDermatofibrosarcoma protuberans (DFSP) is a rare soft tissue sarcoma for which clinical examination up to 10 years is recommended. The objective of this study was to identify prognostic factors for recurrences and metastases that can be used to evaluate the validity of follow‐up schedules after treatment for DFSP.MethodsPatients with DFSP who received treatment between 1991 and 2016 at 3 tertiary centers were included. Cox regression analyses were conducted to identify variables associated with the primary endpoints.ResultsIn total 357 patients were included, with a median age of 38 years (age range, 2‐87 years) and a median follow‐up of 60 months (interquartile range, 24‐115 months). Eighty‐one patients developed recurrent disease (22.7%), and the median time to recurrence was 55.5 months (interquartile range, 20‐90 months). Of these, 50 tumors (61.7%) were identified by patient self‐examination, whereas 3 recurrences (3.7%) were identified at clinical surveillance. For the remaining 28 tumors, no information was available on how the recurrences were identified (34.6%). Fibrosarcomatous change (hazard ratio, 21.865; P < .001), and positive resection margins (hazard ratio, 14.645; P < .001), were independent prognostic factors for recurrence. Metastases occurred in 4 patients (1.1%). All tumors were identified by imaging after patients presented with symptomatic metastases. Fibrosarcomatous change (P < .001) and tumor size >5 cm (P = .014) were associated with the development of metastases.ConclusionsDisease recurrence after resection of DFSP remains a significant issue, whereas metastases are uncommon. The majority of recurrences are identified by patient self‐examination. Consideration should be given to individualized follow‐up schedules based on risk factors for recurrences and metastases.
Expression of tachykinin3 and related reproductive markers in the brain of the African cichlid fish Astatotilapia burtoni
Authors: Butler Julie M. , Maruska Karen P. 
Published: January 2019

ABSTRACTNeurokinin B, encoded by the tachykinin3 gene, plays a crucial role in regulating reproduction in mammals via KNDy neurons and interaction with GnRH. Previous work in teleost fishes has focused on hypothalamic tac3 expression for its role in reproduction, but detailed studies on extra‐hypothalamic tac3 expression are limited. Here, we identified two tac3 genes in the social African cichlid fish Astatotilapia burtoni, only one of which produces a functional protein containing the signature tachykinin motif. In situ hybridization for tac3a mRNA identified cell populations throughout the brain. Numerous tac3a cells lie in several thalamic and hypothalamic nuclei, including periventricular nucleus of posterior tuberculum, lateral tuberal nucleus (NLT), and nucleus of the lateral recess (NRL). Scattered tac3‐expressing cells are also present in telencephalic parts, such as ventral (Vv) and supracomissural (Vs) part of ventral telencephalon. In contrast to other teleosts, tac3 expression was absent from the pituitary. Using double‐fluorescent staining, we localized tac3a‐expressing cells in relation to GnRH and kisspeptin cells. Although no GnRH‐tac3a colabeled cells were observed, dense GnRH fibers surround and potentially synapse with tac3a cells in the preoptic area. Only minimal (<5%) colabeling of tac3a was observed in kiss2 cells. Despite tac3a expression in many nodes of the mesolimbic reward system, it was absent from tyrosine hydroxylase (TH)‐expressing cells, but tac3a cells were located in areas with dense TH fibers. The presence of tac3a‐expressing cells throughout the brain, including in socially relevant brain regions, suggest more diverse functions beyond regulation of reproductive physiology that may be conserved across vertebrates.
Native Chemical Ligation of Peptides and Proteins
Authors: Cistrone Philip A. , Bird Michael J. , Flood Dillon T. , Silvestri Anthony P. , Hintzen Jordi C. J. , Thompson Darren A. , Dawson Philip E. 
Published: January 2019

AbstractFor over 20 years, native chemical ligation (NCL) has played a pivotal role in enabling total synthesis and semisynthesis of increasingly complex peptide and protein targets. Classical NCL proceeds by chemoselective reaction of two unprotected polypeptide chains in near‐neutral‐pH, aqueous solution and is made possible by the presence of a thioester moiety on the C‐terminus of the N‐terminal peptide fragment and a natural cysteine residue on the N‐terminus of the C‐terminal peptide fragment. The reaction yields an amide bond adjacent to cysteine at the ligation site, furnishing a native protein backbone in a traceless manner. This unit highlights a number of recent and powerful advances in the methodology and outlines their particular uses, facilitating application in the synthesis of challenging protein targets. © 2019 by John Wiley & Sons, Inc.
A−H…σ Hydrogen Bonds: Dihydrogen and Cycloalkanes as Proton Acceptors
Authors: Grabowski Sławomir J. 
Published: January 2019

AbstractωB97XD/aug‐cc‐pVTZ calculations were performed for complexes of dihydrogen, cyclopropane, cyclobutane and cyclopentane, with simple proton donating species such as hydrogen fluoride, hydrogen chloride, water, hydrogen cyanide and acetylene. Numerous dependencies between geometrical, energetic and topological parameters of complexes considered were found, since various theoretical approaches were applied: Quantum Theory of ‘Atoms in Molecules’ (QTAIM), Natural Bond Orbital (NBO) method and energy decomposition analysis (EDA). It was confirmed that complexes of dihydrogen and cyclopropane are linked through the A−H…σ interactions that may be classified as hydrogen bonds. In the case of complexes of cyclobutane such hydrogen bonds are rather weak. Other type and also weak A−H…C hydrogen bonds are formed for complexes with cyclopentane.