bluuebunny/crossref_metadata_2025_split huggingface dataset:
Photocatalytic properties of PMMA‐TiO2 class I and class II hybrid nanofibers obtained by electrospinning
Authors: Ohlmaier‐Delgadillo Federico , Castillo‐Ortega Maria Monica , Ramírez‐Bon Rafael , Armenta‐Villegas Lorena , Rodríguez‐Félix Dora Evelia , Santacruz‐ Ortega Hisila , del Castillo‐Castro Teresa , Santos‐Sauceda Irela 
Published: August 2016

ABSTRACTThe preparation, characterization, and photocatalytic activity evaluation of three hybrid fibrous materials composed mainly by poly(methyl methacrylate) (PMMA), methyl methacrylate (MMA): 3‐(trimethoxysilyl) propyl methacrylate (TMSPM): titanium butoxide (TBT), TiO2 nanoparticles (NPTiO2), and TiO2 nanowires (NWTiO2) is studied. Two types of fibeŕs structures were prepared, single and core‐shell structures. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis showed both structures, single and core‐shell, as well as the inorganic phase were dispersed in the hybrid fibers. Infrared spectroscopic analysis (FT‐IR) and thermal analysis showed the organic and inorganic components, as well as the weight percentage of the inorganic phase present in hybrid fibers. The photocatalytic activity of the hybrid fibers class I and II showed that the best photodegradative efficiency for methylene blue in aqueous solution (2.9 × 10−5 M) was 95%, provided by PMMA—10 wt % NPTiO2. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44334.
Room‐Temperature and Aqueous‐Phase Synthesis of Plasmonic Molybdenum Oxide Nanoparticles for Visible‐Light‐Enhanced Hydrogen Generation
Authors: Shi Jiayuan , Kuwahara Yasutaka , Wen Meicheng , Navlani‐García Miriam , Mori Kohsuke , An Taicheng , Yamashita Hiromi 
Published: August 2016

AbstractA straightforward aqueous synthesis of MoO3−x nanoparticles at room temperature was developed by using (NH4)6Mo7O24⋅4 H2O and MoCl5 as precursors in the absence of reductants, inert gas, and organic solvents. SEM and TEM images indicate the as‐prepared products are nanoparticles with diameters of 90–180 nm. The diffuse reflectance UV‐visible‐near‐IR spectra of the samples indicate localized surface plasmon resonance (LSPR) properties generated by the introduction of oxygen vacancies. Owing to its strong plasmonic absorption in the visible‐light and near‐infrared region, such nanostructures exhibit an enhancement of activity toward visible‐light catalytic hydrogen generation. MoO3−x nanoparticles synthesized with a molar ratio of MoVI/MoV 1:1 show the highest yield of H2 evolution. The cycling catalytic performance has been investigated to indicate the structural and chemical stability of the as‐prepared plasmonic MoO3−x nanoparticles, which reveals its potential application in visible‐light catalytic hydrogen production.
Simultaneous Actuator and Sensor Faults Reconstruction Based on Robust Sliding Mode Observer for a Class of Nonlinear Systems
Authors: Ben Brahim Ali , Dhahri Slim , Ben Hmida Fayçal , Sellami Anis 
Published: August 2016

AbstractThis paper proposes a new robust fault reconstruction and estimation design for a class of nonlinear system described by the Takagi‐Sugeno model with unmeasurable premise variables subject to faults affecting actuators, sensor faults, and unknown disturbances. The augmented Takagi‐Sugeno system is introduced with a new fault vector which has two origins: the first one represents actuator faults, the second one denotes faults affecting sensors. The main contribution is focused primarily to conceive a sliding mode observer with two discontinuous terms designed to compensate for fault behavior and disturbance variation from the system states estimation. In the formalism of linear matrix inequalities, we derive sufficient conditions to guarantee the state estimation error stability and to obtain the observer gains. Meanwhile, additional effort is made to achieve simultaneous faults and disturbance reconstruction. Simulation results are given to illustrate the proposed approach performances.
Structural and functional diversity among amyloid proteins: Agents of disease, building blocks of biology, and implications for molecular engineering
Authors: Bleem Alissa , Daggett Valerie 
Published: August 2016

ABSTRACTAmyloids have long been associated with protein dysfunction and neurodegenerative diseases, but recent research has demonstrated that some organisms utilize the unique properties of the amyloid fold to create functional structures with important roles in biological processes. Additionally, new engineering approaches have taken advantage of amyloid structures for implementation in a wide variety of materials and devices. In this review, the role of amyloid in human disease is discussed and compared to the functional amyloids, which serve a largely structural purpose. We then consider the use of amyloid constructs in engineering applications, including their utility as building blocks for synthetic biology and molecular engineering. Biotechnol. Bioeng. 2017;114: 7–20. © 2016 Wiley Periodicals, Inc.
East Meets West – Joint Meeting of European and Asian Pacific Chapters at LIDA Conference
Authors: Levine Emil , Krtalić Maja 
Published: August 2016

EDITOR'S SUMMARYThe 2016 Libraries in the Digital Age (LIDA) Conference in Croatia provided an opportunity for ASIS&T's European and Asian Pacific Chapters to come together for events and discussion of professional issues, with 43 members attending. ASIS&T dignitaries, including past presidents Tefko Saracevic and Diane Sonnenwald, led discussions about how professional associations can aid graduate students starting their careers through networking, academic opportunities and other resources. A Ph.D. forum drew about 60 participants, including LIDA attendees. Special announcements included the winners of top study projects and the LIDA poster contest, earning free ASIS&T membership or a cash award, and a new anonymous donor program for student memberships. The meeting was a valuable channel to promote ASIS&T membership and discuss the Association's broad and local strategic goals.
Activation of an exonic splice‐donor site in exon 30 of CDK5RAP2 in a patient with severe microcephaly and pigmentary abnormalities
Authors: Pagnamenta Alistair T. , Howard Malcolm F. , Knight Samantha J. L. , Keays David A. , Quaghebeur Gerardine , Taylor Jenny C. , Kini Usha 
Published: August 2016

Key Clinical MessageThis report constitutes the first report of a cryptic exonic splice‐donor site in CDK5RAP2, highlights the importance of evaluating novel splice mutations, and suggests that the phenotypic range associated with CDK5RAP2 mutations may include skin pigmentary abnormalities.
Hydroformylation of 2‐Alkynylanilines: Toward an Alternative Methodology for the Synthesis of 3‐Substituted Indoles
Authors: Holzapfel Cedric , Dasilva Etelinda , Den Drijver Laetitia , Bredenkamp Tyler 
Published: August 2016

AbstractA potentially viable route for the synthesis of 3‐substituted indoles is presented herein. The methodology is based on a regioselective Rh‐catalysed hydroformylation of prepared 2‐alkyn‐1‐ylanilines. The requisite 2‐alkynylaniline substrates were prepared in high yields (>85 %) using the Pd‐catalysed Sonogashira reaction. A catalyst complex that comprises RhI(CO)(PPh3)3 and 1,2‐bis(diphenylphosphino)ethane as the ligand allowed the quantitative conversions of the alkynyl substrates with selectivities >75 % for the desired 3‐substituted indoles.
Branched Diol Monomers from the Sequential Hydrogenation of Renewable Carboxylic Acids
Authors: Spanjers Charles S. , Schneiderman Deborah K. , Wang Jay Z. , Wang Jingyu , Hillmyer Marc A. , Zhang Kechun , Dauenhauer Paul J. 
Published: August 2016

AbstractA prominent challenge in replacing petrochemical polymers with bioderived alternatives is the efficient transformation of biomass into useful monomers. In this work, we demonstrate a practical process for the synthesis of multifunctional alcohols from five‐ and six‐carbon acids using heterogeneous catalysts in aqueous media. Design of this process was guided by thermodynamic calculations, which indicate the need for two sequential high‐pressure hydrogenations: one, reduction of the acid to a lactone at high temperature; two, further reduction of the lactone to the corresponding diol or triol at low temperature. For example, the conversion of mesaconic acid into (α or β)‐methyl‐γ‐butyrolactone was achieved with 95 % selectivity at a turnover frequency of 1.2 min−1 over Pd/C at 240 °C. Subsequent conversion of (α or β)‐methyl‐γ‐butyrolactone into 2‐methyl‐1,4‐butanediol was achieved with a yield of 80 % with Ru/C at 100 °C. This process is an efficient method for the production of lactones, diols, and triols, all valuable monomers for the synthesis of bioderived branched polyesters.
Syndiotactic Polymer of Allylcyclopentane by a Metallocene Catalyst
Authors: Wang Wei , Hou Liping , Sheng Jianfang 
Published: August 2016

AbstractSyndiospecific (co)polymerization of some higher α‐olefins was performed by using a metallocene catalyst. Homopolymers of allylcyclopentane, 4‐methyl‐1‐pentene, and allylcyclohexane are highly syndiotactic. The results of the copolymerization of allylcyclopentane with 1‐hexene, 1‐octene, or 1‐decene showed that the incorporation of a linear higher α‐olefin interfered with the syndiospecificity of the catalyst, and the melting point of the resulting copolymer decreased with the incorporation of the comonomer. In contrast, the copolymer of allylcyclopentane with 4‐methyl‐1‐pentene or allylcyclohexane maintained the high syndiotacticity, and the melting point also remained almost unchanged no matter how much the comonomer was incorporated. It followed that the “shape” of the monomer had a significant influence on the structure of the copolymer. The monomers employed in copolymerization with a similar “shape” gave a copolymer with a similar microstructure.
Aromaticity‐Controlled Energy Storage Capacity of the Dihydroazulene‐Vinylheptafulvene Photochromic System
Authors: Skov Anders B. , Broman Søren Lindbæk , Gertsen Anders S. , Elm Jonas , Jevric Martyn , Cacciarini Martina , Kadziola Anders , Mikkelsen Kurt V. , Nielsen Mogens Brøndsted 
Published: August 2016

AbstractPhotochemical conversion of molecules into high‐energy isomers that, after a stimulus, return to the original isomer presents a closed‐cycle of light‐harvesting, energy storage, and release. One challenge is to achieve a sufficiently high energy storage capacity. Here, we present efforts to tune the dihydroazulene/vinylheptafulvene (DHA/VHF) couple through loss/gain of aromaticity. Two derivatives were prepared, one with aromatic stabilization of DHA and the second of VHF. The consequences for the switching properties were elucidated. For the first type, sigmatropic rearrangements of DHA occurred upon irradiation. Formation of a VHF complex could be induced by a Lewis acid, but addition of H2O resulted in immediate regeneration of DHA. For the second type, the VHF was too stable to convert into DHA. Calculations support the results and provide new targets. We predict that by removing one of the two CN groups at C‐1 of the aromatic DHA, the heat storage capacity will be further increased, as will the life‐time of the VHF. Calculations also reveal that a CN group at the fulvene ring retards the back‐reaction, and we show synthetically that it can be introduced regioselectively.
Nucleophilic Aromatic Substitution on Pentafluorophenyl‐Substituted Dipyrranes and Tetrapyrroles as a Route to Multifunctionalized Chromophores for Potential Application in Photodynamic Therapy
Authors: Gutsche Claudia S. , Ortwerth Marlene , Gräfe Susanna , Flanagan Keith J. , Senge Mathias O. , Reissig Hans‐Ulrich , Kulak Nora , Wiehe Arno 
Published: August 2016

AbstractThe application of porphyrinoids in biomedical fields, such as photodynamic therapy (PDT), requires the introduction of functional groups to tune their solubility for the biological environment and to allow a coupling to other active moieties or carrier systems. A valuable motif in this regard is the pentafluorophenyl (PFP) substituent, which can easily undergo a regiospecific nucleophilic replacement (SNAr) of its para‐fluorine atom by a number of nucleophiles. Here, it is shown that, instead of amino‐substitution on the final porphyrinoid or BODIPY (boron dipyrromethene), the precursor 5‐(PFP)‐dipyrrane can be modified with amines (or alcohols). These dipyrranes were transformed into amino‐substituted BODIPYs. Condensation of these dipyrranes with aldehydes gave access to trans‐A2B2‐porphyrins and trans‐A2B‐corroles. By using pentafluorobenzaldehyde, it was possible to introduce another para‐fluorine atom, which enabled the synthesis of multifunctionalized tetrapyrroles. Furthermore, alkoxy‐ and amino‐substituted dipyrranes were applied to the synthesis of A3B3‐hexaphyrins. The polar porphyrins that were prepared by using this method exhibited in vitro PDT activity against several tumor cell lines.
Quenching of pH‐Responsive Luminescence of a Benzoindolizine Sensor by an Ultrafast Hydrogen Shift
Authors: Zhou Jiawang , Outlaw Victor K. , Townsend Craig A. , Bragg Arthur E. 
Published: August 2016

AbstractFluorescent‐sensor design requires consideration of how photochemical dynamics control properties of a sensing state. Transient absorption (TA) spectroscopy reveals an ultrafast net [1,3]‐hydrogen shift following excitation of a protonated methoxy benzoindolizine (bzi) sensor in solution. These photochemical dynamics explain a quenched pH‐responsive fluorescence shift and dramatically reduced fluorescence quantum yield relative to other (e. g. methyl) bzi compounds that do not tautomerize. Calculations predict the energetic and structural feasibility for rearrangement in protonated bzi compounds, such that interaction between the pi‐network and strongly electron‐donating methoxyl must lower the barrier for suprafacial H or H+ shift across an allylic moiety. As bzi compounds broadly exhibit pH‐responsive emission shifts, chemical interactions that modulate this electronic interaction and suppress tautomerization could be used to facilitate binding‐ or surface‐specific acid‐responsive sensing.
Entropic Phase Transitions with Stable Twisted Intermediates of Bio‐Inspired Self‐Assembly
Authors: Tao Kai , Levin Aviad , Jacoby Guy , Beck Roy , Gazit Ehud 
Published: August 2016

AbstractControlling the hierarchical process and capturing the intermediate stage underlying bio‐inspired self‐assembly are pivotal for understanding their aggregation mechanism and exploring possible applications. Here, the self‐assembly of a designed minimal lipopeptide was characterized, showing it to initially self‐assemble to narrow nanotwists, which then ripen to wide nanotwists, and finally transit to hollow nanotubes. The supramolecular phase transitions were revealed to be driven by entropic hydrophobic interactions, rather than by the common mechanism of enthalpy‐related contributions. The transformation dynamics were sufficiently slow to enable detection and characterization of each stage, thus inducing the stable and extensive distributions of twisted intermediates. The findings allow an in‐depth understanding of the hierarchical self‐association of bio‐inspired building blocks and provide a new approach for the preparation of superstructures of unique morphologies.
Meta‐analysis of Vitamin D Deficiency and Risk of Atrial Fibrillation
Authors: Zhang Zhiwei , Yang Yajuan , Ng Chee Yuan , Wang Dandan , Wang Jianlong , Li Guangping , Liu Tong 
Published: August 2016

ABSTRACTBackgroundThere are accumulating studies investigating the association between vitamin D status and the risk of atrial fibrillation (AF). However, the results in these studies were inconsistent in regard to the role of vitamin D deficiency in predicting the development of AF.HypothesisVitamin D deficiency is associated increased risk of AF.MethodsUsing PubMed and Embase databases, we searched for records published before March 2016. Additionally, a manual search was conducted using all review articles on this topic. Of the 587 initially identified records, 8 studies with a total of 27 307 patients were finally analyzed.ResultsIn the categorical variable analysis, vitamin D deficiency was associated with the occurrence of AF (odds ratio: 1.31, 95% confidence interval: 1.06‐1.62, P = 0.01). In the continuous variable analysis, higher vitamin D levels appear to protect against the development of AF (odds ratio: 0.92, 95% confidence interval: 0.87‐0.97, P = 0.002). However, the association is weak on the pooled analysis of prospective cohort studies focused on new‐onset AF (P = 0.07 and 0.04), whereas the pooled analysis of case–control studies mainly assessing for chronic AF strongly support such an association (both P < 0.0001).ConclusionsVitamin D deficiency modestly increases the risk of AF. Further studies are needed to determine the if there is a direct causal relationship between vitamin D levels and AF and whether vitamin D supplements will prevent new‐onset AF.
Evidence for ecological speciation via a host shift in the holly leaf miner,Phytomyza glabricola(Diptera: Agromyzidae)
Authors: Hébert Julie B. , Scheffer Sonja J. , Hawthorne David J. 
Published: August 2016

AbstractEvolutionary radiations have been well documented in plants and insects, and natural selection may often underly these radiations. If radiations are adaptive, the diversity of species could be due to ecological speciation in these lineages. Agromyzid flies exhibit patterns of repeated host‐associated radiations. We investigated whether host‐associated population divergence and evidence of divergent selection exist in the leaf minerPhytomyza glabricolaon its sympatric host plants, the holly species,Ilex coriaceaandI. glabra. UsingAFLPs and nuclear sequence data, we found substantial genetic divergence between host‐associated populations of these flies throughout their geographic range. Genome scans using theAFLPdata identified 13 loci under divergent selection, consistent with processes of ecological speciation.EF‐1αdata suggest that I. glabrais the original host ofP. glabricolaand thatI. coriaceais the novel host, but theAFLPdata are ambiguous with regard to directionality of the host shift.
Influence of smoking with smoke flavorings on the oxidative stability of farmed sea bass fillets monitored by 1H NMR and FTIR
Authors: Vidal Natalia P. , Manzanos María J. , Goicoechea Encarnación , Guillén María D. 
Published: August 2016

Farmed European sea bass (Dicentrarchus labrax) fillets were smoked with three commercial smoke flavorings. Unsmoked and smoked fillets were submitted to oxidative conditions to study their oxidative stability. To this aim, at regular intervals of time under oxidative conditions, their lipids were extracted and studied by Fourier transform mid‐infrared spectroscopy (FTIR) and Proton nuclear magnetic resonance (1H NMR). Both kinds of spectra provide markers referred to the beginning and extension of the lipid degradation and of the formation of new compounds resulting from the oxidation process. Obtaining these data from FTIR is easier, simpler, and quicker than it is from 1H NMR, but this latter technique provides, simultaneously, additional interesting information about the sample. The increase of the oxidative stability of sea bass fillets as a consequence of smoking is proved, as well as the influence on this increase of the concentration of certain phenolic smoke components in the fillets.Practical applications: Farmed European sea bass is widely available in the market, in some occasions the supply being greater than the demand. This study could be very interesting for the seafood industry, because smoking of sea bass fillets with smoke flavorings not only extends their shelf‐life, but also provides them with special sensory characteristics, diversifying its presence in the market as a new ready‐to‐eat product. Nevertheless, it must be taken into account that not all the smoke flavorings show the same effect on fish. This study demonstrates that the smoke flavoring composition and its application method have a great influence on the oxidative stability of smoked sea bass fillets.A study of the lipid oxidative stability of unsmoked and smoked sea bass fillets with three different commercial smoke flavorings was undertaken. To this aim, unsmoked and smoked sea bass fillets were submitted to oxidative conditions and their lipids were extracted and analyzed by Fourier transform infrared spectroscopy (FTIR) and Proton nuclear magnetic resonance (1H NMR) periodically.
Synthesis of conjugated linoleic acid by microwave‐assisted alkali isomerization using propylene glycol as solvent
Authors: Silva‐Ramírez Ana Sonia , Rocha‐Uribe Alejandro , González‐Chávez Marco Martín , González Carmen 
Published: August 2016

Conjugated linoleic acid (CLA) is a group of isomers of linoleic acid (LA) with a conjugated double‐bond system that occurs in trace amounts in natural oils. As result of the beneficial properties on the health, bioactive isomers of CLA (cis9,trans11‐CLA and trans10,cis12‐CLA) have been industrially produced by alkali isomerization of LA. A large amount of studies regarding the CLA production might be found; however, new approaches as the use of microwave irradiation have been recently suggested. Here, we develop an efficient and sustainable method to selectively produce bioactive CLA by microwave‐assisted isomerization of LA using propylene glycol as solvent. The investigated reaction variables were solvent/LA mass ratio (1:1–6:1), catalyst/LA mass ratio (0.25:1–0.6:1), temperature (160–180°C), catalyst type (KOH or NaOH), and reaction time. The results showed that: (i) KOH increased the production of conjugated trans‐trans isomers; (ii) a considerable reduction of propylene glycol on the reaction was possible using NaOH; and (iii) the reaction time was drastically reduced in comparison to conventional heating. Thus, the optimum conditions for the cis9,trans11‐CLA and trans10,cis12‐CLA production (91.21% in equimolar ratio) were: NaOH at a catalyst/LA mass ratio of 0.5:1 and solvent/LA mass ratio of 1:1 at 160°C during 4 min.Practical applications: CLA has been subject of growing interest in nutrition and the food industry due to its wide range of biological activities including anti‐carcinogenic and anti‐atherogenic properties. Here, the chemical synthesis of CLA by microwave‐assisted alkali isomerization was studied in order to lower the production costs by decreasing both, the propylene glycol content (the most expensive solvent used for this kind of reaction) and the reaction time. In comparison to conventional heating, reaction time was drastically reduced by employing microwave heating while the selective synthesis of cis9,trans11‐CLA and trans10,cis12‐CLA was achieved at low solvent conditions when the reaction conditions were optimized. In this sense, the methodology developed in this work could be used in order to obtain more efficiently and sustainably the bioactive forms of CLA, which in turn could be used in the manufacture of functional foods or dietary supplements.cis9,trans11‐CLA and trans10,cis12‐CLA were selectively synthetized through basic catalysis of linoleic acid in propylene glycol under microwave irradiation.