bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the Gold‐Catalyzed Generation of Vinyl Cations from 1,5‐Diynes
Authors: Wurm Thomas , Bucher Janina , Duckworth Sarah B. , Rudolph Matthias , Rominger Frank , Hashmi A. Stephen K. 
Published: February 2017

AbstractConjugated 1,5‐diynes bearing two aromatic units at the alkyne termini were converted in the presence of a gold catalyst. Under mild conditions, aryl‐substituted dibenzopentalenes were generated. Calculations predict that aurated vinyl cations are key intermediates of the reaction. A bidirectional approach provided selective access to the angular annulated product in high yield, which was explained by calculations.
Surface molecularly imprinted polymer microspheres based on nano‐TiO2 for selective recognition of kaempferol
Authors: Huang Zejun , Zhang Zhimiao , Xia Qiang , Li Chunli , Yun Yanbin 
Published: February 2017

ABSTRACTThe molecular imprinting technique is a new method for preparing molecularly imprinted polymers (MIPs) with specific molecular recognition sites for certain target molecules. In this study, a novel, facile preparation method was presented, called “seed precipitation polymerization,” for the synthesis of MIPs via surface imprinting and a support matrix. In the polymerization process, kaempferol was used as the template molecule, methacrylic acid as the functional monomer, nano‐TiO2 as the support, azodiisobutyronitrile as the initiator, and ethylene glycol dimethacrylate as the crosslinker in acetonitrile solvent. The synthesized T‐MIP and MIP were analyzed by infrared spectroscopy and scanning electron microscopy. In addition, the obtained polymers were evaluated by adsorption isotherms and dynamic curves for their selective recognition properties for kaempferol. The results show that T‐MIP shows regular spherical particles; the adsorption dynamic curves of T‐MIP show that the adsorption capacity increases with time and reaches a maximum value and then finally reaches equilibrium, and the T‐MIP exhibits a higher affinity for kaempferol than does the MIP. The adsorption follows pseudo‐second‐order kinetics, the Freundlich adsorption equation fits the experimental data well, and there is strong evidence for multiple‐layer adsorption. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44888.
A reinvestigation of a colorimetric method aimed at quantifying minute amounts of carboxylic acids present in polystyrene and poly(n‐alkyl methacrylate)s
Authors: Kerloc'h Brendan , Brissault Blandine , Penelle Jacques , Atvars Teresa Dib Zambon 
Published: February 2017

ABSTRACTA reinvestigation of a method (Christoff, M.; Yamaki, S. B.; de Oliveira, M. G.; Atvars, T. D. Z. J. Appl. Polym. Sci. 2004, 92, 830–838) aimed at quantitatively determining trace amounts of residual carboxylic acid functional groups in polymethacrylates and polystyrene has been carried out. The original technique was based on the monitoring of an absorption band in the UV–visible region (610 nm) that appears after known amounts of polymer are added to a benzene solution containing the basic form of the Nile Blue A dye. It is shown here that the assumption upon which the methodology is based, that is, the occurrence of a 1:1 stoichiometric and complete proton transfer of the carboxylic acid to the dye, is invalid and yields greatly underestimated values for the COOH contents, possibly by 2–3 orders of magnitude. In addition, temperature strongly influences the equilibrium constant for the acid‐base reaction. Lastly, preparation and storage of the analytical solution was found to be problematic, supporting earlier claims that hydrolysis of Nile Blue A base does occur when preparing the benzene solution and/or over storage, yielding Nile Red dye whose absorption in the visible part of the spectrum significantly overlaps. Based on the above results, further use of this technique, at least in its quantitative version, should be discouraged. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44931.
Morphologic Patterns Formed by the Anomalous Fibers Occurring Along the Anterior Capsule of the Crystalline Lens in People With the Long Anterior Zonule Trait
Authors: Roberts Daniel K. , Yang Yongyi , Morettin Christina E. , Newman Tricia L. , Roberts Mary F. , Wilensky Jacob T. 
Published: February 2017

ABSTRACTPeople with the long anterior zonule (LAZ) trait, which may have prevalence near 2%, have zonular fibers that extend more central than usual along the anterior capsule of the crystalline lens. The anomalous fibers can be observed in vivo with clinical slit lamp biomicroscopy after pharmacologic pupil dilation, and although minimally studied, the LAZ trait may have importance to glaucoma, retinal degeneration, and cataract surgery. To further characterize LAZ morphology, a custom computer program was used to trace LAZ fibers seen on retro‐illumination photos acquired during previous study at an academic, urban eye care facility in Chicago, IL. There were 59 African‐Americans (54 female; median age = 70 years, 53–91 years) included in the analysis. After initial review of the zonule tracings, we identified three basic LAZ patterns. We called one pattern (47% of right eyes) a “non‐segmental LAZ pattern,” which was predominated by fibers that could be visually traced to the dilated pupil border where they became obscured by the iris. Another pattern (35% of right eyes), the “segmental LAZ pattern,” was predominated by fibers that appeared to terminate abruptly without detectable extension to the pupil border. The third pattern (18% of right eyes), the “mixed LAZ pattern,” had a more equivalent mixture of the other two fiber morphologies. Compared to the “non‐segmental” group, the “segmental” LAZ eyes had smaller central zonule‐free zones (P < 0.0001), and they tended to exhibit fewer LAZ fibers (P = 0.07). These data improve understanding of LAZ clinical anatomy and may be helpful to future investigation. Anat Rec, 300:1336–1347, 2017. © 2017 Wiley Periodicals, Inc.
Lanthanide(III)‐Based Multicolor Luminescent Hybrid Gel for Amine Sensing
Authors: Liu Caixia , Wang Tianren , Yang Daqing , Li Zhiqiang , Li Huanrong 
Published: February 2017

AbstractBridged polysilsesquioxanes (BPs) show great potential in the development of lanthanide‐based luminescent materials, owing to their capacity to loading lanthanide complexes with high concentration and their flexible processability. A novel BP precursor, consisting of a C3‐symmetrical benzene central core moiety, capable of sensitizing the luminescence of Eu3+ and Tb3+ is reported. Tunable, full‐color luminescent gels were facilely prepared by mixing the as‐synthesized precursor and Ln3+ ions in appropriate solvents. By either changing the Eu3+/Tb3+ molar ratio or altering the excitation wavelength, the emission colors of the final gels can be finely tuned. Additionally, the yellow‐colored emissive gel with a molar ratio of Eu3+ to Tb3+ of 0.5 can be used as an effective ratiometric luminescent sensor for distinguishing amines with lower pKa (<5) from those with higher pKa (>9).
Mixing Adaptive Fault Tolerant Control of Quadrotor UAV
Authors: Büyükkabasakal Kemal , Fi̇dan Barış , Savran Aydoğan 
Published: February 2017

AbstractIn this paper, a multiple model adaptive fault tolerant control scheme is proposed based on mixing of the control signals generated by a set of linear quadratic state feedback controllers. Each of these controllers are designed considering closed loop system performance for a particular range of fault. Stability analysis of the proposed scheme is provided. The paper further presents specific design and implementation for motion control of quadrotor unmanned aerial vehicles (UAVs). The designed mixing adaptive controller is tested via real‐time experiments on Quanser Qball‐X4 UAVs. The experimental results verify the efficiency of the proposed scheme.
Association between psychological health and wound complications after surgery
Authors: Britteon P , Cullum N , Sutton M 
Published: February 2017

Abstract

Background
Surgical wound complications remain a major cause of morbidity, leading to higher costs and reduced quality of life. Although psychological health is widely considered to affect wound healing, the evidence on wound outcomes after surgery is mixed. Studies generally focus on small samples of patients undergoing a specific procedure and have limited statistical power.

Methods
This study investigated the relationship between three different measures of anxiety and/or depression and seven adverse surgical outcomes using observational data collected before and after surgery between 2009 and 2011. A wide range of confounding factors was adjusted for, including patient demographics, physical co-morbidities, health-related behaviours, month of operation, procedure complexity and treating hospital.

Results
The estimation sample included 176 827 patients undergoing 59 410 hip replacements, 64 145 knee replacements, 38 328 hernia repairs and 14 944 varicose vein operations. Patients with moderate anxiety or depression had an increased probability of wound complications after a hip replacement (odds ratio (OR) 1·17, 95 per cent c.i. 1·11 to 1·24). They were more likely to be readmitted for a wound complication (OR 1·20, 1·02 to 1·41) and had an increased duration of hospital stay by 0·19 (95 per cent c.i. 0·15 to 0·24) days. Estimated associations were consistent across all four types of operation and for each measure of anxiety and/or depression.

Conclusion
Preoperative psychological health is a significant risk factor for adverse wound outcomes after surgery for four of the procedures most commonly performed in England.
Chemical Characteristics, Antimicrobial, and Cytotoxic Activities of the Essential Oil of Egyptian Cinnamomum glanduliferum Bark
Authors: Taha AlShaimaa M. , Eldahshan Omayma A. 
Published: February 2017

The essential oil isolated from the bark of Cinnamomum glanduliferum (Wall) Meissn grown in Egypt was screened for its composition as well as its biological activity for the first time. The chemical composition was analyzed by GC and GC/MS. The antimicrobial activity of the oil was assessed using agar‐well diffusion method toward representatives for each of Gram‐positive bacteria, Gram‐negative bacteria, and fungi. The cytotoxic activity was checked using three human cancer cell lines. Twenty seven compounds were identified, representing 99.07% of the total detected components. The major constituents were eucalyptol (65.87%), terpinen‐4‐ol (7.57%), α‐terpineol (7.39%). The essential oil possessed strong antimicrobial activities against Escherichia coli, with an activity index of one and minimum inhibitory concentration (MIC) equaling to 0.49 μg/ml. The essential oil possessed good antimicrobial activities against methicillin‐resistant Staphylococcus aureus, Geotrichum candidum, Pseudomonas aeruginosa, Bacillus subtilis, Helicobacter pylori, Aspergillus fumigatus (MIC: 7.81, 1.95, 7.81, 0.98, 31.25, and 32.5 μg/ml, respectively). A considerable activity was reported against S. aureus and Mycobacterium tuberculosis (MIC; 32.5 and 31.25 μg/ml, respectively). The extracted oil was cytotoxic to colon (HCT‐116), liver (HepG2), and breast (MCF‐7) carcinoma cell lines with IC50 of 9.1, 42.4, and 57.3 μg/ml, respectively. These results revealed that Egyptian Cinnamomum glanduliferum bark oil exerts antimicrobial and cytotoxic activities mainly due to eucalyptol and other major compounds.
Construction of Acid–Base Synergetic Sites on Mg‐bearing BEA Zeolites Triggers the Unexpected Low‐Temperature Alkylation of Phenol
Authors: Xie Jingyan , Zhuang Wenxia , Zhang Wei , Yan Ning , Zhou Yu , Wang Jun 
Published: February 2017

AbstractNovel Mg‐bearing BEA zeolites are synthesized to simultaneously endow significantly enhanced basicity without compromising acidity over the zeolite framework. Serving as efficient solid acid–base bifunctional catalysts, they achieve the liquid‐phase selective methylation of phenol with methanol to produce o‐ and p‐cresol (o/p=2) under mild conditions. The method is readily extendable to the alkylation of phenols with various alcohols. Stereo‐ and regioselectivity (>95 % for p‐product) was attained on the alkylation of phenol with bulky tert‐butyl alcohol, rendering the first acid–base cooperative shape‐selective catalysis relying on the basicity of zeolites. A preliminary mechanistic analysis reveals that the remarkable activity and shape‐selectivity come from the superior special acidic–basic synergetic catalytic sites on the uniform microporous channels of the BEA zeolite.
Application of chemometric methods for multi‐elemental characterization of fruit juices and nectars analysed in the Portuguese Total Diet Studies pilot study
Authors: Coelho Inês , Rego Andreia , Gueifão Sandra , Nascimento Ana Claudia , Castanheira Isabel 
Published: February 2017

Multivariate analysis was applied to test the adequacy of pooling samples versus single units as a sampling strategy to estimate dietary intake and risk assessment of chemical elements in nonalcoholic beverages. The contents of 18 minerals and trace elements (Cr, Mn, Cu, Zn, As, Se, Mo, Sr, Co, Cd, Sn, Pb Fe, Mg, Ca, P, Na, and K) in fruit juices and nectars were determined by inductively coupled plasma–optical emission spectrometry and inductively coupled plasma–mass spectrometry. Arsenic speciation was done with high‐performance liquid chromatographer‐inductively coupled plasma–mass spectrometry. The data obtained in pooled samples and single units were then studied by analysis of variance and least significant difference tests, Spearman's correlation, principal component analysis, and cluster analysis. Analysis of variance and least significant difference tests were used to evaluate analytical data from pooled samples and single units. Values of individual units and pooled samples were statistically different with the exception of Se (P < .05), illustrating pooling as an inadequate strategy. Spearman's correlation displayed significant correlations between the following pairs: P‐K (0.924), Mo‐K (0.888), Mo‐P (0.876), and Ca‐Mg (0.846), indicating that chemical elements could be from the same source, having a natural occurrence, or the same exposure sources. By applying principal component analysis and cluster analysis, it was possible to classify juices and nectars by fruit type and geographical origin. It was observed that 2 principal components accounted for 59% of the total variance in the data. Cluster analysis classified samples into 5 clusters. Combined chemometric tools are suited to select appropriate laboratory sampling strategies for risk assessment. Application of chemometric methods to analytical data may be useful to group samples by similar characteristics for the purpose of Total Diet Studies.
Towards Monodisperse Star‐Shaped Ladder‐Type Conjugated Systems: Design, Synthesis, Stabilized Blue Electroluminescence, and Amplified Spontaneous Emission
Authors: Jiang Yi , Fang Mei , Chang Si‐Ju , Huang Jin‐Jin , Chu Shuang‐Quan , Hu Shan‐Ming , Liu Cheng‐Fang , Lai Wen‐Yong , Huang Wei 
Published: February 2017

AbstractA novel series of monodisperse star‐shaped ladder‐type oligo(p‐phenylene)s, named as TrL‐n (n=1–3), have been explored. Their thermal and electrochemical properties, fluorescence transients, photoluminescence quantum yields, density functional theory calculations, electroluminescence (EL) and amplified spontaneous emission (ASE) properties have been systematically investigated to unravel the molecular design on optoelectronic properties. The resulting materials showed excellent structural perfection, free of chemical defects, and exhibited great thermal stability (Td: 404–418 °C and Tg: 147–184 °C) and amorphous glassy morphologies. Compared with their corresponding linear counterparts FL‐m (m=1–3), TrL‐n showed only little bathochromic shifts (5–12 nm) for the absorption maxima λmax in both solution and films. The star‐shaped ladder‐type compounds exhibited enhanced optical stability and suppressed low‐energy emission. Their EL spectra exhibited excellent stability with increasing the driving voltage from 6 to 12 V. Moreover, superior low ASE thresholds were recorded for TrL‐n compared with FL‐m. Rather low ASE threshold (29 nJ per pulse or 1.60 μJ cm−2) was recorded for TrL‐3, demonstrating their promising potential as excellent gain media. This study provides a novel design concept to develop monodisperse star‐shaped ladder‐type materials with excellent structural perfection, which are vital for shedding light on exploring robust organic emitters for optoelectronic applications.
Design of Na+‐Selective Fluorescent Probes: A Systematic Study of the Na+‐Complex Stability and the Na+/K+ Selectivity in Acetonitrile and Water
Authors: Schwarze Thomas , Müller Holger , Schmidt Darya , Riemer Janine , Holdt Hans‐Jürgen 
Published: February 2017

AbstractThere is a tremendous demand for highly Na+‐selective fluoroionophores to monitor the top analyte Na+ in life science. Here, we report a systematic route to develop highly Na+/K+ selective fluorescent probes. Thus, we synthesized a set of fluoroionophores 1, 3, 4, 5, 8 and 9 (see Scheme ) to investigate the Na+/K+ selectivity and Na+‐ complex stability in CH3CN and H2O. These Na+‐probes bear different 15‐crown‐5 moieties to bind Na+ stronger than K+. In the set of the diethylaminocoumarin‐substituted fluoroionophores 1–5, the following trend of fluorescence quenching 1>3>2>4>5 in CH3CN was observed. Therefore, the flexibility of the aza‐15‐crown‐5 moieties in 1–4 determines the conjugation of the nitrogen lone pair with the aromatic ring. As a consequence, 1 showed in CH3CN the highest Na+‐induced fluorescence enhancement (FE) by a factor of 46.5 and a weaker K+ induced FE of 3.7. The Na+‐complex stability of 1–4 in CH3CN is enhanced in the following order of 2>4>3>1, assuming that the O‐atom of the methoxy group in the ortho‐position, as shown in 2, strengthened the Na+‐complex formation. Furthermore, we found for the N‐(o‐methoxyphenyl)aza‐15‐crown‐5 substituted fluoroionophores 2, 8 and 9 in H2O, an enhanced Na+‐complex stability in the following order 8>2>9 and an increased Na+/K+ selectivity in the reverse order 9>2>8. Notably, the Na+‐induced FE of 8 (FEF=10.9), 2 (FEF=5.0) and 9 (FEF=2.0) showed a similar trend associated with a decreased K+‐induced FE [8 (FEF=2.7)>2 (FEF=1.5)>9 (FEF=1.1)]. Here, the Na+‐complex stability and Na+/K+ selectivity is also influenced by the fluorophore moiety. Thus, fluorescent probe 8 (Kd=48 mm) allows high‐contrast, sensitive, and selective Na+ measurements over extracellular K+ levels. A higher Na+/K+ selectivity showed fluorescent probe 9, but also a higher Kd value of 223 mm. Therefore, 9 is a suitable tool to measure Na+ concentrations up to 300 mm at a fluorescence emission of 614 nm.
Photoswitching of Dihydroazulene Derivatives in Liquid‐Crystalline Host Systems
Authors: Petersen Anne Ugleholdt , Jevric Martyn , Mandle Richard J. , Sims Mark T. , Moore John N. , Cowling Stephen J. , Goodby John W. , Nielsen Mogens Brøndsted 
Published: February 2017

AbstractPhotoswitches and dyes in the liquid‐crystalline nematic phase have the potential for use in a wide range of applications. A large order parameter is desirable to maximize the change in properties induced by an external stimulus. A set of photochromic and nonphotochromic dyes were investigated for these applications. It was found that a bent‐shaped 7‐substituted dihydroazulene (DHA) photoswitch exhibited liquid‐crystalline properties. Further investigation demonstrated that this material actually followed two distinct reaction pathways on heating, to a deactivated form by a 1,5‐sigmatropic shift and to a linear 6‐substituted DHA. In addition, elimination of hydrogen cyanide from the photoactive DHA gave both bent and linear azulene dyes. In a nematic host that has no absorbance around 350 nm, it was found that only the linear DHA derivative has nematic properties; however, both 6‐ and 7‐substituted DHAs were found to have large order parameters. In the nematic host, ring opening of either DHA to the corresponding vinylheptafulvene resulted in a decrease in dichroic order parameter and an unusually fast back‐reaction to a mixture of both DHAs. Likewise, only the linear azulene derivative showed mesomorphic properties. In the same nematic host, large order parameters were also observed for these dyes.
Synthesis, Biological Evaluation, and Molecular Docking Studies on the DNA Binding Interactions of Platinum(II) Rollover Complexes Containing Phosphorus Donor Ligands
Authors: Fereidoonnezhad Masood , Niazi Maryam , Shahmohammadi Beni Mahnaz , Mohammadi Shima , Faghih Zeinab , Faghih Zahra , Shahsavari Hamid R. 
Published: February 2017

AbstractCyclometalated rollover complexes of the type [PtMe(κ2N,C‐bipyO‐H)(L)] [bipyO‐H=cyclometalated 2,2′‐bipyridine N‐oxide; L=tricyclohexylphosphine (PCy3, 2 a), 2‐(diphenylphosphino)pyridine (PPh2py, 2 b), P(OPh)3 (2 c)] were synthesized by treating [PtMe(κ2N,C‐bipyO‐H)(SMe2)] (1) with various monodentate phosphine and phosphite ligands. These complexes were characterized by NMR spectroscopy, and the structure of 2 a was confirmed by single‐crystal X‐ray diffraction. Complex 1 was treated with bis(diphenylphosphino)methane (dppm) at a 1:1 ratio to give the corresponding [PtMe(κ2N,C‐bipyO‐H)(κ1P‐dppm)] (3 b) complex, in which the dppm ligand acts as a monodentate pendant ligand. The biological activities of these complexes were evaluated against a panel of four standard cancer cell lines: lung carcinoma (A549), ovarian carcinoma (OV‐90 and SKOV3), and breast carcinoma (MCF‐7). Complexes 2 c and especially 3 b indicated effective potent cytotoxic activity regarding the cell lines. Electrophoresis mobility shift assays and molecular‐modeling investigations were performed to determine the specific binding mode and the binding orientation of these alkylating agents to DNA. Detection of cellular reactive oxygen species was also determined.
Engineering of Optically Encoded Microbeads with FRET‐Free Spatially Separated Quantum‐Dot Layers for Multiplexed Assays
Authors: Bilan Regina S. , Krivenkov Victor A. , Berestovoy Mikhail A. , Efimov Anton E. , Agapov Igor I. , Samokhvalov Pavel S. , Nabiev Igor , Sukhanova Alyona 
Published: February 2017

AbstractQuantum dot (QD) encoded microbeads are emerging for multiplexed analysis of biological markers. The quantitative encoding of microbeads prepared with different concentrations of QDs of different colors suffers from resonance energy transfer from the QDs fluorescing at shorter wavelengths to the QDs fluorescing at longer wavelengths. Here, we used the layer‐by‐layer deposition technique to spatially separate QDs of different colors with several polymer layers so that the distance between them would be larger than the Förster energy transfer radius. We performed fluorescence lifetime measurements to investigate and determine the conditions excluding significant resonance energy transfer between QDs within QD‐encoded microbeads. Additionally, the number of QDs adsorbed onto microbeads was systematically established and multilayer structures of the QD‐encoded microbead shells were characterized by scanning probe nanotomography. Finally, we prepared eight populations of FRET‐free microbeads encoded with QDs of three colors at two intensity levels and demonstrated that all the optical codes are excitable at a single wavelength and may be clearly identified in three channels of a flow cytometer. The developed approach for engineering QD‐encoded microbeads that are free from optical artefacts related to inter‐QD resonance energy transfer paves the way to quantitative QD‐based multiplexed assays.