bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cyclic polylactides via simultaneous ring‐opening polymerization and polycondensation catalyzed by dibutyltin mercaptides
Authors: Kricheldorf Hans R. , Weidner Steffen M. , Scheliga Felix 
Published: August 2017

ABSTRACTl‐Lactide is polymerized in bulk at 160 °C either with dibutyltin bis(benzylmercaptide) (SnSBzl), dibutyltin bis(benzothiazole 2‐mercaptide) (SnMBT), or with dibutyltin bis(pentafluorothiophenolate) (SnSPF) as catalysts. SnSBzl yields linear polylactides having benzylthio‐ester end groups in addition to cyclic polylactides, whereas SnMBT and SnSPF mainly or exclusively yield cyclic polylactides. This finding, together with model reactions, indicates that the SnS catalysts promote a combined ring‐opening polymerization and polycondensation process including end‐to‐end cyclization. SnMBT caused slight racemization (3%–5%), when used at 160 °C. With SnSPF optically pure cyclic poly(l‐lactide)s with high‐molecular weights can be prepared at 160 °C. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 3767–3775
A cross‐cultural convergent parallel mixed methods study of what makes a cancer‐related symptom or functional health problem clinically important
Authors: Giesinger Johannes M. , Aaronson Neil K. , Arraras Juan I. , Efficace Fabio , Groenvold Mogens , Kieffer Jacobien M. , Loth Fanny L. , Petersen Morten Aa. , Ramage John , Tomaszewski Krzysztof A. , Young Teresa , Holzner Bernhard ,   on behalf of the EORTC Quality of Life Group
Published: August 2017

AbstractObjectiveIn this study, we investigated what makes a symptom or functional impairment clinically important, that is, relevant for a patient to discuss with a health care professional (HCP). This is the first part of a European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Group project focusing on the development of thresholds for clinical importance for the EORTC QLQ‐C30 questionnaire and its corresponding computer‐adaptive version.MethodsWe conducted interviews with cancer patients and HCPs in 6 European countries. Participants were asked to name aspects of a symptom or problem that make it clinically important and to provide importance ratings for a predefined set of aspects (eg, need for help and limitations of daily functioning).ResultsWe conducted interviews with 83 cancer patients (mean age, 60.3 y; 50.6% men) and 67 HCPs. Participants related clinical importance to limitations of everyday life (patients, 65.1%; HCPs, 77.6%), the emotional impact of a symptom/problem (patients, 53.0%; HCPs, 64.2%), and duration/frequency (patients, 51.8%; HCPs, 49.3%). In the patient sample, importance ratings were highest for worries by partner or family, limitations in everyday life, and need for help from the medical staff. Health care professionals rated limitations in everyday life and need for help from the medical staff to be most important.ConclusionsLimitations in everyday life, need for (medical) help, and emotional impact on the patient or family/partner were found to be relevant aspects of clinical importance. Based on these findings, we will define anchor items for the development of thresholds for clinical importance for the EORTC measures in a Europe‐wide field study.
Engineered, highly reactive substrates of microbial transglutaminase enable protein labeling within various secondary structure elements
Authors: Rachel Natalie M. , Quaglia Daniela , Lévesque Éric , Charette André B. , Pelletier Joelle N. 
Published: August 2017

AbstractMicrobial transglutaminase (MTG) is a practical tool to enzymatically form isopeptide bonds between peptide or protein substrates. This natural approach to crosslinking the side‐chains of reactive glutamine and lysine residues is solidly rooted in food and textile processing. More recently, MTG's tolerance for various primary amines in lieu of lysine have revealed its potential for site‐specific protein labeling with aminated compounds, including fluorophores. Importantly, MTG can label glutamines at accessible positions in the body of a target protein, setting it apart from most labeling enzymes that react exclusively at protein termini. To expand its applicability as a labeling tool, we engineered the B1 domain of Protein G (GB1) to probe the selectivity and enhance the reactivity of MTG toward its glutamine substrate. We built a GB1 library where each variant contained a single glutamine at positions covering all secondary structure elements. The most reactive and selective variants displayed a >100‐fold increase in incorporation of a recently developed aminated benzo[a]imidazo[2,1,5‐cd]indolizine‐type fluorophore, relative to native GB1. None of the variants were destabilized. Our results demonstrate that MTG can react readily with glutamines in α‐helical, β‐sheet, and unstructured loop elements and does not favor one type of secondary structure. Introducing point mutations within MTG's active site further increased reactivity toward the most reactive substrate variant, I6Q‐GB1, enhancing MTG's capacity to fluorescently label an engineered, highly reactive glutamine substrate. This work demonstrates that MTG‐reactive glutamines can be readily introduced into a protein domain for fluorescent labeling.
An adaptive EWMA scheme‐based CUSUM accumulation error for efficient monitoring of process location
Authors: Zaman Babar , Lee Muhammad Hisyam , Riaz Muhammad , Abujiya Mu'azu Ramat 
Published: August 2017

AbstractThe examination of product characteristics using a statistical tool is an important step in a manufacturing environment to ensure product quality. Several methods are employed for maintaining product quality assurance. Quality control charts, which utilize statistical methods, are normally used to detect special causes. Shewhart control charts are popular; their only limitation is that they are effective in handling only large shifts. For handling small shifts, the cumulative sum (CUSUM) and the exponential weighted moving average (EWMA) are more practical. For handling both small and large shifts, adaptive control charts are used. In this study, we proposed a new adaptive EWMA scheme. This scheme is based on CUSUM accumulation error for detection of wide range of shifts in the process location. The CUSUM features in the proposed scheme help with identification of prior shifts. The proposed scheme uses Huber and Tukey bisquare functions for an efficient shift detection. We have used average run length (ARL) as performance indicator for comparison, and our proposed scheme outperformed some of the existing schemes. An example that uses real‐life data is also provided to demonstrate the implementation of the proposed scheme.
Theoretical assessing on the coordination mode and bonding in heteronuclear group‐13 dimetallocene
Authors: Lu Feifei , Yang Lihua , Dang Yaru , Li Qingzhong , Li Xiaoyan 
Published: August 2017

AbstractIn this article, the coordination mode, the nature of metal–ligand interaction and dimetallic bonding in heteronuclear group‐13 dimetallocene (CpMM′CpI2; Cp = C5H5, M/M′=B, Al, Ga, In, and Tl) have been investigated within the framework of the atoms in molecules theory, electron localization function, and energy decomposition analysis. The calculated results show that the symmetries of the title compounds, the coordination modes between the metal and ligand, the strength and nature of M‐ligand interaction and MM′ bond are well correlated with the periodicity changing of group‐13 metal atom going from the lighter to the heavier (B, Al, Ga, In, and Tl). The heavier group 13 metal atom is corresponding to the higher symmetry, stronger metal–ligand interaction, and weaker dimetallic bond. The covalent characters of both metal–ligand interaction and dimetallic bond are decreasing in the sequence of M′=Al, Ga, In, and Tl, for the same M atom.
Direct analysis of volatile organic compounds in foods by headspace extraction atmospheric pressure chemical ionisation mass spectrometry
Authors: Perez‐Hurtado P. , Palmer E. , Owen T. , Aldcroft C. , Allen M.H. , Jones J. , Creaser C.S. , Lindley M.R. , Turner M.A. , Reynolds J.C. 
Published: August 2017

RationaleThe rapid screening of volatile organic compounds (VOCs) by direct analysis has potential applications in the areas of food and flavour science. Currently, the technique of choice for VOC analysis is gas chromatography/mass spectrometry (GC/MS). However, the long chromatographic run times and elaborate sample preparation associated with this technique have led a movement towards direct analysis techniques, such as selected ion flow tube mass spectrometry (SIFT‐MS), proton transfer reaction mass spectrometry (PTR‐MS) and electronic noses. The work presented here describes the design and construction of a Venturi jet‐pump‐based modification for a compact mass spectrometer which enables the direct introduction of volatiles for qualitative and quantitative analysis.MethodsVolatile organic compounds were extracted from the headspace of heated vials into the atmospheric pressure chemical ionization source of a quadrupole mass spectrometer using a Venturi pump. Samples were analysed directly with no prior sample preparation. Principal component analysis (PCA) was used to differentiate between different classes of samples.ResultsThe interface is shown to be able to routinely detect problem analytes such as fatty acids and biogenic amines without the requirement of a derivatisation step, and is shown to be able to discriminate between four different varieties of cheese with good intra and inter‐day reproducibility using an unsupervised PCA model. Quantitative analysis is demonstrated using indole standards with limits of detection and quantification of 0.395 μg/mL and 1.316 μg/mL, respectively.ConclusionsThe described methodology can routinely detect highly reactive analytes such as volatile fatty acids and diamines without the need for a derivatisation step or lengthy chromatographic separations. The capability of the system was demonstrated by discriminating between different varieties of cheese and monitoring the spoilage of meats.
Event‐triggered adaptive backstepping control for parametric strict‐feedback nonlinear systems
Authors: Li Yuan‐Xin , Yang Guang‐Hong 
Published: August 2017

SummaryThis paper proposes a novel adaptive backstepping control method for parametric strict‐feedback nonlinear systems with event‐sampled state and input vectors via impulsive dynamical systems tools. In the design procedure, both the parameter estimator and the controller are aperiodically updated only at the event‐sampled instants. An adaptive event sampling condition is designed to determine the event sampling instants. A positive lower bound on the minimal intersample time is provided to avoid Zeno behavior. The closed‐loop stability of the adaptive event‐triggered control system is rigorously proved via Lyapunov analysis for both the continuous and jump dynamics. Compared with the periodic updates in the traditional adaptive backstepping design, the proposed method can reduce the computation and the transmission cost. The effectiveness of the proposed method is illustrated using 2 simulation examples.
Output consensus for heterogeneous multiagent systems with Markovian switching network topologies
Authors: Meng Min , Liu Lu , Feng Gang 
Published: August 2017

SummaryThis paper investigates the output consensus problem of heterogeneous continuous‐time multiagent systems under randomly switching communication topologies. The switching mechanism is governed by a time‐homogeneous Markov process, whose states correspond to all possible communication topologies among agents. A novel dynamic consensus controller is proposed. The controller gains are designed based on the information of the expectation graph and the solutions to regulator equations. Furthermore, a necessary and sufficient condition is presented for output consensus of the controlled multiagent system in mean square sense. Finally, a simulation example is provided to corroborate the effectiveness of the proposed controller.
Size‐Selective Silver‐Induced Evolution of Mn3O4−Ag Nanocomposites for Effective Ethanol Sensing
Authors: Rahaman Hasimur , Kundu Susmita , Ghosh Sujit Kumar 
Published: August 2017

AbstractTrimanganese tetraoxide (Mn3O4)−silver (Ag) nanocomposites have been synthesized by seed‐mediated growth of manganese oxide by alkaline hydrolysis of manganese precursor on preformed silver nanoparticles at water/n‐heptane interface. The morphology of the nanocomposites has been varied by individual addition of five size‐selective silver nanoparticles for the evolution of the manganese components. Varieties of spectroscopic and microscopic techniques have been used to characterize these materials. Now, the efficacy of these as‐synthesized nanocomposites has been demonstrated towards the sensing of various hazardous volatile organic compounds, exhibiting high sensitivity to ethanol compared to other components. Moreover, the structure‐function relationship of the Mn3O4−Ag nanocomposites upon variation of the size of silver particles towards the sensory activity of ethanol has been elucidated.
In Situ Growth of 3D Nano‐array Ni0.85Se/NF Structure Supercapattery Electrode with Excellent Cyclic Stability and Superior Energy Density
Authors: An Weidan , Gao Yanfang , Liu Jinrong 
Published: August 2017

AbstractThe growth of three‐dimensional(3D) nano‐array Ni0.85Se structure on Ni foam (Ni0.85Se/NF) in situ by hydrothermal treatment using Na2SeO3⋅5H2O as Se source is presented in this article. Moreover, when fabricated as binder‐free supercapattery electrode, the 3D nano‐array Ni0.85Se/NF structure demonstrates an excellent specific capacitance of 1344 and 686.50 F⋅g−1 at current densities of 0.5 and 5 A⋅g−1, which was calculated by 4 mg active mass of Ni0.85Se. Impressively, the areal capacitance of 5.38 and 2.75 F⋅cm−2 can be got at the current densities of 2 and 20 mA⋅cm−2. Furthermore, the supercapattery electrode exhibits a superior cyclic stability with 70.1 % capacity retention after 5000 cycles, which is notable for a selenide based supercapacitor. When assembled into Ni0.85Se//AC asymmetric supercapacitor, the operating voltage was expanded to 1.6 V, a good specific capacitance of 184.70 C⋅g−1 at 0.5 A⋅g−1 and remains 35.33 C⋅g−1 at 4 A⋅g−1 is achieved. The supercapattery electrode demonstrates an outstanding rate performance as a coin type asymmetric device, obtaining a great energy density of 38.48 Wh⋅kg−1 at the power density of 375 W⋅kg−1. The aforementioned results suggested that the 3D nano‐array Ni0.85Se structure may a potential electrode for next generation supercapacitors.
Ammonia‐Treated Ordered Mesoporous Carbons with Hierarchical Porosity and Nitrogen‐Doping for Lithium‐Sulfur Batteries
Authors: Liu Dan , Li Yabo , Zheng Dong , Wang Gongwei , Qu Deyu , Xie Zhi‐zhong , Li Chunlei , Lei Jiaheng , Qu Deyang 
Published: August 2017

AbstractDeveloped porosity and high‐level heteroatom‐doping are necessary to acquire the advanced carbon materials as sulfur hosts for lithium‐sulfur batteries with high sulfur loading. We herein demonstrated that hierarchical ordered micro/mesoporous carbons with controllable porosity and nitrogen functionality could be prepared via two scalable steps which are based on aqueous self‐assembly and ammonia activation processes. The effects of porosity and nitrogen doping upon the electrochemical performances of the carbon/sulfur hybrids as the cathodes in lithium‐sulfur batteries were investigated. It demonstrated that the carbon materials with balanced porosity and nitrogen‐doping level could effectively increase the conductivity of sulfur and alleviate the “shuttle effect” and exhibit high specific capacity, good rate performance, and superior cycling stability.
Fabrication of Nano‐CuO@ZnO for the Synthesis of Functionalized β‐Enaminone Derivatives from β‐Nitrostyrenes, Aliphatic/Aromatic Amines and 1,3‐Dicarbonyl/4‐Hydroxy Coumarin
Authors: Saha Arijit , Payra Soumen , Akhtar Sohel , Banerjee Subhash 
Published: August 2017

AbstractHere, we have reported synthesis, characterization of CuO doped ZnO nanoparticles (CuO@ZnO NPs) and its applications for the synthesis of functionalized β‐enaminone derivatives via one‐pot three component reactions of β‐nitrostyrenes, aliphatic/aromatic amines or alcohols and 5,5‐dimethylcyclohexane‐1,3‐dione/4‐hydroxycoumarin. The present CuO@ZnO NPs‐catalyzed sustainable protocol has enabled access to variety of β‐enaminone derivatives in moderate to excellent yields (61‐96%) in comparatively short reaction time periods (2‐3 h). The catalyst was found to be very stable under the reaction conditions and easily recovered from reaction mixture by filtration and recycled for at least ten times without significant loss in its catalytic efficiency.
Oxidation Decomposition Mechanism of Fluoroethylene Carbonate‐Based Electrolytes for High‐Voltage Lithium Ion Batteries: A DFT Calculation and Experimental Study
Authors: Xia Lan , Tang Bencan , Yao Linbin , Wang Kai , Cheris Anastasia , Pan Yueyang , Lee Saixi , Xia Yonggao , Chen George Z. , Liu Zhaoping 
Published: August 2017

AbstractThe oxidative decomposition mechanism of fluoroethylene carbonate (FEC) used in high‐voltage batteries is investigated by using density functional theory (DFT). Radical cation FEC•+ is formed from FEC by transferring one electron to electrode and the most likely decomposition products are CO2 and 2‐fluoroacetaldehyde radical cation. Other possible products are CO, formaldehyde and formyl fluoride radical cations. These radical cations are surrounded by much FEC solvent and their radical center may attack the carbonyl carbon of FEC to form aldehyde and oligomers of alkyl carbonates, which is similar with the oxidative decomposition of EC. Then, our experimental result reveals that FEC‐based electrolyte has rather high anodic stability. It can form a robust SEI film on the positive electrode surface, which can inhibit unwanted electrolyte solvent and LiPF6 salts decomposition, alleviate Mn/Ni dissolution and therefore, improve the coulombic efficiency and the cycling stability of high voltage LiNi0.5Mn1.5O4 positive electrodes. This work displays that FEC‐based electrolyte systems have considerable potential replacement of the EC‐based electrolyte for the applications in 5 V Li‐ion batteries.
Modulation of Protolytic Equilibrium of Bichromophoric Coumarin‐30 Dye with Cucurbit[8]uril Encapsulation
Authors: Barooah Nilotpal , Khurana Raman , Mohanty Jyotirmayee , Bhasikuttan Achikanath C. 
Published: August 2017

AbstractHost‐guest interaction of macrocyclic receptor, cucurbit[8]uril (CB8), with neutral bichromophoric coumarin 30 (C30) dye has been investigated using various spectroscopic tools. Absorption and fluorescence emission results along with 1H NMR data have demonstrated the existence of host‐guest complex of C30 dye with CB8 host in a 1:2 and 3:2 (CB8:C30) stoichiometries. Comparative studies with the photophysical aspects of the protonated C30 dye (at pH 3) confirmed that interaction of neutral C30 dye (at pH 7) with CB8 has led to the host assisted protonation of C30 in the CB8:C30 complex, registering an upward supramolecular pKa shift of about 3 units. The 3:2 stoichiometric complex exhibits strong excimer emission and is dictated by the structural features of C30. Due to this complexation not only we accomplish modulation in the photophysics of the dye, but also it enhances the aqueous solubility of C30, especially at pH 7. Taking advantage of CB8 assisted tunable pKa shift, currently we are pursuing the prospects of using photostable coumarin dyes for cellular imaging studies as well as their applicability as aqueous dye laser systems.
Extraction of Base from Eichhornia crassipes and Its Implication in Palladium‐Catalyzed Suzuki Cross‐Coupling Reaction
Authors: Sarmah Manashi , Dewan Anindita , Thakur Ashim J , Bora Utpal 
Published: August 2017

AbstractThe utilization of a sustainable and eco‐friendly alternative medium derived from water borne species Eichhornia crassipes (Common name: Water Hyacinth) for the Suzuki cross‐coupling reaction at room temperature was reported. The system provides an in situ basic condition via metal extraction from ash water extract of Eichhornia crassipes, which delivers a dual performance in the catalytic application. The distribution of metal contents in the ash was characterized by EDX (Energy‐dispersive X‐ray spectroscopy) analysis. The basicity of the medium may possibly be due to the formation of corresponding metal oxides or hydroxides in its water extract. The application of this ash water extract results in an effective cross‐coupling in palladium catalyzed Suzuki reaction without any external promoter or ligand. The central attraction of our reaction system is the fruitful utilization of highly abundant unwanted weeds instead of destruction of ecologically important plants or plant parts. The present system highlights an excellent green pathway that fits the global urge of sustainable development and will prevail wide application in variable synthetic studies.
Regioselective Transition‐Metal‐Free Synthesis of Diverse Benzothiazoles by Thermally Induced Cyclization of ortho‐Halobenzanilides
Authors: Jang Keun Sam , Shin Dong Seok , Song Ho Rim , Lee Byoung Se , Chi Dae Yoon 
Published: August 2017

AbstractThe highly regioselective and efficient synthesis of diverse substituted‐benzothiazoles, including heterocyclic units and amino groups, was achieved in moderate to high yields from ortho‐bromothiobenzanilides, ortho‐bromoarylthioureas, ortho‐bromobenzanilides, and ortho‐dibromobenzanilides, regardless of the electron density and substituted positions, via the prevalent carbon‐sulfur bond formation by thermally induced intramolecular cyclization reaction without using any metal sources or other additives. Polysubstituted‐benzothiazoles, particularly 2,4‐, 2,6‐disubstituted, and 2,4,6‐trisubstituted benzothiazoles, could be efficiently synthesized by a facile cascade reaction from appropriate ortho‐bromobenzanilides under general thiolation conditions. This benign reaction represents a straightforward and practical approach toward diverse substituted‐benzothiazoles. In addition, the remaining bromine substituent of the resulting products was further utilized as a functional handle for the additional diversification and exploited as a complementary solution for the adjustment of harsh reaction condition. This methodology not only allows for the elaboration of benzothiazole molecules, but also provides a new valuable synthetic tool for a range of pharmaceutical applications.
Physicochemical Characterization of Lecithin/Isopropyl Myristate Reverse Micelles
Authors: Fu Yan , Liu Yan , Fang Yu , Qi Xiaodan , Cao Deying 
Published: August 2017

AbstractReverse micelles have good thermodynamic stability, small particle size, good self‐assembly performance, and controlled drug release versus other microparticle transdermal drug delivery systems. Here, a reverse micelles solution and a gel system formed by self‐assembly of insulin aqueous solution/lecithin/isopropyl myristate (IPM) were used for transdermal delivery of insulin. The size, size distribution, morphology and rheology of the reverse micelles were characterized with dynamic light scattering (DLS), small angle x‐ray scattering (SAXS), differential scanning calorimetry (DSC), viscosity measurement, and freeze fracture transmission electron microscopy (FF‐TEM). The findings suggested that lecithin/isopropyl myristate self‐assembled reverse micelles were spherical with uniform particle sizes (< 100 nm). The water in the reverse micelle was in the form of bound water, and the diameter of the water pool was about 4 nm. The reverse micelle solution and gel appeared as a pseudo‐plastic fluid. The gel was thixotropic, which benefits transdermal delivery.