bluuebunny/crossref_metadata_2025 huggingface dataset:
Proliferating cell nuclear antigen restores the enzymatic activity of a DNA ligase I deficient in DNA binding
Authors: Trasviña‐Arenas Carlos H. , Cardona‐Felix Cesar S. , Azuara‐Liceaga Elisa , Díaz‐Quezada Corina , Brieba Luis G.
Published: February 2017

Proliferating cell nuclear antigen (PCNA) coordinates multienzymatic reactions by interacting with a variety of protein partners. Family I DNA ligases are multidomain proteins involved in sealing of DNA nicks during Okazaki fragment maturation and DNA repair. The interaction of DNA ligases with the interdomain connector loop (IDCL) of PCNA through its PCNA‐interacting peptide (PIP box) is well studied but the role of the interacting surface between both proteins is not well characterized. In this work, we used a minimal DNA ligase I and two N‐terminal deletions to establish that DNA binding and nick‐sealing stimulation of DNA ligase I by PCNA are not solely dependent on the PIP box–IDCL interaction. We found that a truncated DNA ligase I with a deleted PIP box is stimulated by PCNA. Furthermore, the activity of a DNA ligase defective in DNA binding is rescued upon PCNA addition. As the rate constants for single‐turnover ligation for the full‐length and truncated DNA ligases are not affected by PCNA, our data suggest that PCNA stimulation is achieved by increasing the affinity for nicked DNA substrate and not by increasing catalytic efficiency. Surprisingly C‐terminal mutants of PCNA are not able to stimulate nick‐sealing activity of Entamoeba histolytica DNA ligase I. Our data support the notion that the C‐terminal region of PCNA may be involved in promoting an allosteric transition in E. histolytica DNA ligase I from a spread‐shaped to a ring‐shaped structure. This study suggests that the ring‐shaped PCNA is a binding platform able to stabilize coevolved protein–protein interactions, in this case an interaction with DNA ligase I.
Mastering the Photothermal Effect in Liquid Crystal Networks: A General Approach for Self‐Sustained Mechanical Oscillators
Authors: Gelebart Anne Helene , Vantomme Ghislaine , Meijer E. W. , Broer Dirk J.
Published: February 2017

Chemical networks and molecular switches dominate the area of research geared toward macroscopic motion of materials. A counter‐intuitive approach to create self‐sustained oscillation by light irradiation of ordinary photostabilizers in splay‐aligned liquid‐crystalline networks made from commercial mesogens is developed. Photostabilizers or any molecules that are able to quickly dissipate the absorbed light through heat, by vibrational and/or rotational modes, can reach self‐oscillating macroscopic motion where self‐shadowing plays a critical role. The mechanical self‐oscillation is linked to temperature oscillations and the asymmetric response over the film thickness. Only a localized responsive zone, acting as hinge, activates the oscillation of a beam‐shaped device. The outcome of this research is extended from UV to near‐IR actuation, making bulk applications to convert sunlight into mechanical work within reach.
Selective localization of organic montmorillonite nanoparticles in multilayered high‐density polyethylene/polyamide 6 composites
Authors: Xie Gaoyi , Yu Jie , Qin Shuhao , Sun Jing , Yang Zhao , Wei Liangqiang , Ji Yubi , He Wentao , Xu Guomin
Published: February 2017

To achieve a selective localization of nanoparticles in multilayered two‐component polymer blends, an intentional two‐step process, first pre‐compounding and then co‐extruding, was employed to prepare multilayered high‐density polyethylene (HDPE)/polyethylene‐grafted maleic anhydride (PE‐g‐MAH)/organic montmorillonite (OMMT)‐polyamide 6 (PA6) nanocomposites. The dispersion ofOMMTwas evaluated by transmission electron microscopy (TEM) and X‐ray diffraction (XRD). The results showed that the localization ofOMMTwas tunable with different content ofPE‐g‐MAH. By comparing the localization ofOMMTin a single‐layered nanocomposite with that in the multilayered nanocomposites, as well as by theoretically calculating wetting coefficients of the multilayered nanocomposites, the migration mechanism ofOMMTwas revealed. As demonstrated by differential scanning calorimetry (DSC), transmission rate measurement and tensile test, the selective localization ofOMMTin the multilayered nanocomposites could increase crystallinity degree of the two‐polymer components, enhancing oxygen barrier property and tensile strength of the nanocomposties.
Trends in Volunteer Mentoring in the United States: Analysis of a Decade of Census Survey Data
Authors: Raposa Elizabeth B. , Dietz Nathan , Rhodes Jean E.
Published: February 2017

Over the past decade, considerable resources have been devoted to recruiting volunteer mentors and expanding mentoring programs. It is unclear whether these efforts have helped to counter the broader national trends of declining volunteer rates. The current study uses data from the Volunteering Supplement of the Current Population Survey (CPS), sponsored by the U.S. Census Bureau and U.S. Bureau of Labor Statistics, to explore population‐level trends in mentoring over the past decade. Results suggest that mentoring rates have remained relatively stable over the past decade, but that the population of mentors has changed somewhat in terms of age, ethnicity, educational background, and region of the United States. In addition, certain sectors of the mentor population show higher rates of attrition from 1 year to the next. Findings have important implications for the development of recruitment, training, and mentor support practices within mentoring organizations, as well as policies designed to meet the needs of at‐risk youth in the U.S.
Anxiety genetics: Dispatches from the frontier
Authors: Smoller Jordan W.
Published: February 2017

Anxiety disorders are the most common class of psychiatric disorders and incur an enormous burden in terms of economic costs, disability and personal suffering. Despite their public health importance and documented heritability, genetic research aimed at identifying the genetic contributions to these disorders has had limited success, particularly in comparison to recent advances in the genetics of other major psychiatric disorders. The major factor contributing to this lagging progress has been a dearth of well‐powered genomic studies. As a result, the genetic basis of anxiety disorders remains a largely uncharted frontier. In this Special Issue, we bring together dispatches from this frontier, reflecting a range of strategies being pursued including genomewide common variant association studies, exome sequencing, genetic prediction of treatment response, cross‐disorder genetic epidemiology, and the prospects for dissecting underlying anxiety domains using the RDoC framework. Overall, these efforts underscore the genetic and phenotypic complexity of pathologic anxiety and the urgent need for more powerful and comprehensive analyses if we are to make real progress in advancing this important frontier. © 2017 Wiley Periodicals, Inc.
A giant among dwarfs: a new species of galago (Primates: Galagidae) from Angola
Authors: Svensson Magdalena S. , Bersacola Elena , Mills Michael S. L. , Munds Rachel A. , Nijman Vincent , Perkin Andrew , Masters Judith C. , Couette Sébastien , Nekaris K. Anne‐Isola , Bearder Simon K.
Published: February 2017

Objectives

Based on vocalization recordings of an unknown galago species, our main objectives were to compare morphology and call structure with known closely‐related taxa and describe a new species of galago.

Materials and methods

We conducted field surveys in three forest habitats along the escarpment region in western Angola (Kumbira Forest, Bimbe Area, and Northern Scarp Forest), and examined galago specimens from museums worldwide. We digitized and analyzed calls using Avisoft SASLab Pro software. We also compared museum specimens from Angola with other Galago and Galagoides specimens, and conducted comparative analyses (ANOVA and between group principle component analysis) based on a set of twelve linear measurements of skulls and teeth.

Results

We describe the new species to which we give the name Angolan dwarf galago, Galagoides kumbirensis sp. nov. The new species has a loud and characteristic crescendo call, used by other Galagoides spp. (sensu stricto) in West Africa to attract companions and repel rivals. However, this call shows species‐typical differences from its closest relatives. Galagoides kumbirensis sp. nov. is also distinguished by differences in the skull morphology, pelage color and facial markings, as well as a larger body size, similar to that of Galago moholi, which is not known to be sympatric.

Conclusion

This discovery points to the importance of Angolan forests as refuges for endemic biodiversity. These forests are under severe threat from overexploitation, and there is an urgent need to establish conservation measures and designate protected areas.
Pathogenic role of anti–signal recognition protein and anti–3‐Hydroxy‐3‐methylglutaryl‐CoA reductase antibodies in necrotizing myopathies: Myofiber atrophy and impairment of muscle regeneration in necrotizing autoimmune myopathies
Authors: Arouche‐Delaperche Louiza , Allenbach Yves , Amelin Damien , Preusse Corinna , Mouly Vincent , Mauhin Wladimir , Tchoupou Gaelle Dzangue , Drouot Laurent , Boyer Olivier , Stenzel Werner , Butler‐Browne Gillian , Benveniste Olivier
Published: February 2017

Objective

Immune‐mediated necrotizing myopathies (IMNM) may be associated with either anti–signal recognition protein (SRP) or anti–3‐hydroxy‐3‐methylglutaryl‐CoA reductase (HMGCR) antibodies (Abs), and the titer of these Abs is correlated with disease activity. We investigated whether anti‐SRP and anti‐HMGCR Abs could be involved in muscle damage.

Methods

Muscle biopsies of patients were analyzed for atrophy and regeneration by measuring fiber size and by performing immunostaining of neonatal myosin heavy chain. To further understand the role of the Abs in the pathology, we performed muscle cell coculture with the Abs. Atrophy and regeneration were evaluated based on the myotube surface area as well as gene and cytokine profiles.

Results

In muscle biopsies of patients with anti‐SRP+ and anti‐HMGCR+ Abs, a large number of small fibers corresponding to both atrophic and regenerating fibers were observed. In vitro, anti‐SRP and anti‐HMGCR Abs induced muscle fiber atrophy and increased the transcription of MAFbx and TRIM63. In addition, the muscle fiber atrophy was associated with high levels of inflammatory cytokines: tumor necrosis factor, interleukin (IL)‐6, and reactive oxygen species. In the presence of anti‐SRP or anti‐HMGCR Abs, mechanisms involved in muscle regeneration were also impaired due to a defect of myoblast fusion. This defect was associated with a decreased production of IL‐4 and IL‐13. The addition of IL‐4 and/or IL‐13 totally rescued fusion capacity.

Interpretation

These data show that molecular mechanisms of atrophy and regeneration are affected and contribute to loss of muscle function occurring in IMNM. This emphasizes the potential interest of targeted therapies addressing these mechanisms. Ann Neurol 2017;81:538–548
Highly dispersed copper/ppm palladium nanoparticles as novel magnetically recoverable catalyst for Suzuki reaction under aqueous conditions at room temperature
Authors: Lamei Kamran , Eshghi Hossein , Bakavoli Mehdi , Rostamnia Sadegh
Published: February 2017

An efficient procedure based on arginine‐modified Fe3O4@carbon magnetic nanoparticles (FCA MNPs) with highly dispersed copper nanoparticles (Cu NPs) and 92.8 ppm of Pd is reported for room temperature Suzuki reaction. For enhancing the activity of this Cu‐based heterogeneous catalyst, special arginine amino acid as a ligand with high content of heteroatoms was immobilized onto the Fe3O4@carbon MNPs to increase the electron density. Cu(II) ions were then loaded on the surface of the FCA MNPs and reduced to achieve uniformly dispersed Cu NPs. An aqueous mixture of metal hydroxides such as KOH, Ba(OH)2, Ca(OH)2, Mg(OH)2 as a green, non‐toxic and basic medium was used for the Suzuki reaction at room temperature. This catalyst could also be recovered and reused with no loss of activity over six successful runs.
Miscible blends of biobased poly(lactide) with poly(methyl methacrylate): Effects of chopped glass fiber incorporation
Authors: Cousins Dylan S. , Lowe Corinne , Swan Dana , Barsotti Robert , Zhang Mingfu , Gleich Klaus , Berry Derek , Snowberg David , Dorgan John R.
Published: February 2017

Poly(lactide) (PLA) and poly(methyl methacrylate) (PMMA) are melt compounded with chopped glass fiber using laboratory scale twin‐screw extrusion. Physical properties are examined using differential scanning calorimetry (DSC), dynamic mechanical thermal analysis (DMTA), thermogravimetric analysis (TGA), tensile testing, impact testing, X‐ray computed tomography (CT) scanning, and field emission scanning electron microscopy (FE‐SEM). Molecular weight is determined using gel permeation chromatography (GPC). Miscibility of the blends is implied by the presence of a single glass transition temperature and homogeneous morphology. PLA/PMMA blends tend to show positive deviations from a simple linear mixing rule in their mechanical properties (e.g., tensile toughness, modulus, and stress at break). The addition of 40 wt % glass fiber to the system dramatically increases physical properties. Across all blend compositions, the tensile modulus increases from roughly 3 GPa to roughly 10 GPa. Estimated heat distortion temperatures (HDTs) are also greatly enhanced; the pure PLA sample HDT increases from 75 °C to 135 °C. Fiber filled polymer blends represent a sustainable class of earth abundant materials which should prove useful across a range of applications. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44868.
Hydroxypropyl cellulose‐based esters for thermal energy storage by grafting with palmitic‐stearic binary acids
Authors: Chen Weiwang , Weng Wenguo , Fu Ming
Published: February 2017

Fatty acid mixed esters (i.e., HPCMEs) with the onset phase change temperature around 32 °C were successfully synthesized by grafting palmitic‐stearic binary acids (PA‐SA) onto hydroxypropyl cellulose (HPC). The effects of reaction time, reaction temperature, initial ratio of reactants, and stirring speed on grafting ratio (GR) were explored. Characterizations by FTIR, 1H NMR, DSC, and TGA were also performed to investigate their structure, thermal storage, and decomposition behavior. The results reveal that the prepared HPCMEs as thermoplastic copolymers exhibit high enthalpies, good repeatability, and enhanced thermal resistance properties. With the introduction of HPC rigid skeletons, gradual volatilization of fatty acids during use is well solved. The prepared HPCMEs thus are expected to have wide prospects for thermal energy storage owing to their proper phase change temperatures and excellent integrated performance. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44949.
Structural changes in cartilage and collagen studied by high temperature Raman spectroscopy
Authors: Fields Mark , Spencer Nicholas , Dudhia Jayesh , McMillan Paul F.
Published: February 2017

Understanding the high temperature behavior of collagen and collagenous tissue is important for surgical procedures and biomaterials processing for the food, pharmaceutical, and cosmetics industries. One primary event for proteins is thermal denaturation that involves unfolding the polypeptide chains while maintaining the primary structure intact. Collagen in the extracellular matrix of cartilage and other connective tissue is a hierarchical material containing bundles of triple‐helical fibers associated with water and proteoglycan components. Thermal analysis of dehydrated collagen indicates irreversible denaturation at high temperature between 135°C and 200°C, with another reversible event at ∼60‐80°C for hydrated samples. We report high temperature Raman spectra for freeze‐dried cartilage samples that show an increase in laser‐excited fluorescence interpreted as conformational changes associated with denaturation above 140°C. Spectra for separated collagen and proteoglycan fractions extracted from cartilage indicate the changes are associated with collagen. The Raman data also show appearance of new features indicating peptide bond hydrolysis at high temperature implying that molecular H2O is retained within the freeze‐dried tissue. This is confirmed by thermogravimetric analysis that show 5‐7 wt% H2O remaining within freeze‐dried cartilage that is released progressively upon heating up to 200°C. Spectra obtained after exposure to high temperature and re‐hydration following recovery indicate that the capacity of the denatured collagen to re‐absorb water is reduced. Our results are important for revealing the presence of bound H2O within the collagen component of connective tissue even after freeze‐drying and its role in denaturation that is accompanied by or perhaps preceded by breakdown of the primary polypeptide structure.
microRNA‐216b inhibits cell proliferation and migration in human melanoma by targeting FOXM1 in vitro and in vivo
Authors: Sun Mengyao , Wang Xiaopeng , Tu Chen , Wang Shuang , Qu Jianqiang , Xiao Shengxiang
Published: February 2017

MicroRNAs (miRNAs) play an increasingly important role in cancer growth by coordinately suppressing genes that control cell migration, proliferation, and invasion. The above results can be achieved through the regulation of gene expression by miRNAs by suppressing translation or the direct sequence‐specific degradation of the targeted mRNA. In the present study, we indicate that the expression of miR‐216b could be effectively repressed both in human melanoma tissues through a comparison with primary melanoma and in human melanoma cell lines through a comparison with a normal human keratinocyte line. Moreover, miR‐216b induced a clear decrease in melanoma cell proliferation and migration in vitro. Forkhead box M1 (FOXM1) was confirmed as a target gene of miR‐216b, and the overexpression of miR‐216b markedly repressed the luciferase activity of reporter plasmids containing the FOXM1 3′‐UTR (untranslated region). Furthermore, miR‐216b suppressed melanoma cell growth in nude mice in vivo, with the effects of miR‐216b overexpression on melanoma cell growth and proliferation reversed by FOXM1 overexpression. The results demonstrated that miR‐216b is a tumor suppressor in melanoma, identified the FOXM1 signaling pathway as a target of miR‐216b action, and suggested a potential therapeutic role for miR‐216b in melanoma.
The Influence of Alcohols in Driving the Morphology of Magnesium Chloride Nanocrystals
Authors: Thushara K. S. , D'Amore Maddalena , Piovano Alessandro , Bordiga Silvia , Groppo Elena
Published: February 2017

MgCl2 nanocrystals prepared in the presence of methanol and ethanol were characterized by complementing surface‐science tools with a systematic quantum‐mechanical investigation of the stability order (in terms of Gibbs free energy) of different MgCl2 surfaces in the presence of the two alcohols. Both alcohols drastically change the overall stability and the stability order of the exposed surfaces, mainly as a consequence of the entropic contribution to the Gibbs free energy, hence inhibiting or promoting crystal growth in certain directions. The environment‐dependent occurrence of the MgCl2 surfaces may influence the structure and properties of the supported TixCl4−x sites in the MgCl2/TiCl4 precatalyst, which has important implications in the design of morphologically controlled Ziegler–Natta catalysts.
Nb‐Doped Rutile TiO2 Mesocrystals with Enhanced Lithium Storage Properties for Lithium Ion Battery
Authors: Lan Tongbin , Zhang Weifeng , Wu Nae‐Lih , Wei Mingdeng
Published: February 2017

A homogeneous Nb‐doped rutile TiO2 mesocrystal material was synthesized successfully through a facile hydrothermal route. The incorporation of Nb5+ not only promotes the crystallization of the building subunits of the rutile TiO2 mesocrystal, but also improves the electrochemical performance at higher current rates. A capacity of 96.3 mAh g−1 at a current density as high as 40 C and an excellent long‐term cycling stability with a capacity loss of approximately 0.006 % per cycle at 5 C could be achieved when an appropriate amount of Nb5+ was doped into rutile TiO2 mesocrystal. The reasons for the improvement of rate capability may be attributed to the enhancement of electronic conductivity, Li‐ion diffusion kinetics, and the surface storage property for the Nb‐doped rutile TiO2 mesocrystal.
Orthogonal Click Postfunctionalization of Alternating Copolymers Prepared by Nitroxide‐Mediated Polymerization
Authors: Tesch Matthias , Kudruk Sergej , Letzel Matthias , Studer Armido
Published: February 2017

Nitroxide‐mediated polymerization (NMP) was applied to prepare alternating copolymers using 1,1,1,3,3,3‐hexafluoroisopropyl acrylate (HFIPA) 1 and ((6‐trimethylsilyl)‐hex‐5‐yn‐1‐yl)vinyl ether (THVE) 2 as monomers. The alternating sequence of the resulting poly(HFIPA‐alt‐THVE) 3 was proved by using tandem mass spectrometry (MS/MS) and further supported by 1H NMR spectroscopy. Alternating alkyne and activated ester moieties of copolymer 3 were further functionalized with organic azides and amines using sequential Cu‐catalyzed azide–alkyne click (CuAAC) and amidation reactions, providing dually functionalized poly(acrylamide‐alt‐triazole) polymers 5. Water‐soluble alternating poly(acrylic acid‐alt‐triazole) copolymers 9 were obtained by saponification of HFIP esters. 1H and 19F NMR spectroscopy, IR spectroscopy as well as gel permeation chromatography (GPC) were used to characterize the polymers before and after functionalization.
Carbazole‐Linked Near‐Infrared Aza‐BODIPY Dyes as Triplet Sensitizers and Photoacoustic Contrast Agents for Deep‐Tissue Imaging
Authors: Gawale Yogesh , Adarsh Nagappanpillai , Kalva Sandeep Kumar , Joseph Joshy , Pramanik Manojit , Ramaiah Danaboyina , Sekar Nagaiyan
Published: February 2017

Four new N‐ethylcarbazole‐linked aza‐boron‐dipyrromethene (aza‐BODIPY) dyes (8 a,b and 9 a,b) were synthesized and characterized. The presence of the N‐ethylcarbazole moiety shifts their absorption and fluorescence spectra to the near‐infrared region, λ≈650–730 nm, of the electromagnetic spectrum. These dyes possess strong molar absorptivity in the range of 3–4×104 m−1 cm−1 with low fluorescence quantum yields. The triplet excited state and singlet oxygen generation of these dyes were enhanced upon iodination at the core position. The core‐iodinated dyes 9 a,b showed excellent triplet quantum yields of about 90 and 75 %, with singlet oxygen generation efficiency of about 70 and 60 % relative to that of the parent dyes. Derivatives 8 a,b showed dual absorption profiles, in contrast to dyes 9 a,b, which had the characteristic absorption band of aza‐BODIPY dyes. DFT calculations revealed that the electron density was spread over the iodine and dipyrromethene plane of 9 a,b, whereas in 8 a,b the electron density was distributed on the carbazole group and dipyrromethene plane of aza‐BODIPY. The uniqueness of these aza‐BODIPY systems is that they exhibit efficient triplet‐state quantum yields, high singlet oxygen generation yields, and good photostability. Furthermore, the photoacoustic (PA) characteristics of these aza‐BODIPY dyes was explored, and efficient PA signals for 8 a were observed relative to blood serum with in vitro deep‐tissue imaging, thereby confirming its use as a promising PA contrast agent.
Weak Supramolecular Interactions Governing Parallel and Antiparallel DNA Quadruplexes: Insights from Large‐Scale Quantum Mechanics Analysis of Experimentally Derived Models
Authors: Yurenko Yevgen P. , Novotný Jan , Marek Radek
Published: February 2017

The topology and energetics of guanine (G) quadruplexes is governed by supramolecular interactions within their strands. In this work, an extensive quantum mechanical (QM) study has been performed to analyze supramolecular interactions that shape the stems of (4+0) parallel (P) and (2+2) antiparallel (AP) quadruplex systems. The large‐scale (≈400 atoms) models ofPandAPwere constructed from high‐quality experimental structures. The results provide evidence that each of thePandAPstructures is shaped by a distinct network of supramolecular interactions. Analysis of electron topological characteristics of hydrogen bonds inPandAPsystems indicates that thePmodel benefits from stronger intratetrad hydrogen bonding. For intertetrad stacking interactions, both noncovalent interaction plot and energy decomposition analysis approaches suggest that the stem of thePquadruplex benefits more from stacking than that of theAPstem; the difference in energetic stabilization for the two topologies is about 10 %. Stronger hydrogen‐bonding and stacking interactions in the stem of thePquadruplex, relative to those in theAPsystem, can be an important indicator to explain the experimental observations that guanine‐rich oligonucleotides tend to form all‐parallel stems with anall‐antiorientation of nucleobases. However, in addition to intrinsic stabilization, partial desolvation effects, which affect the energetics and dynamics of the G‐quadruplex folding process, call for further investigations.
Effective Access to Multivalent Inhibitors of Carbonic Anhydrases Promoted by Peptide Bioconjugation
Authors: Kanfar Nasreddine , Tanc Muhammet , Dumy Pascal , Supuran Claudiu T. , Ulrich Sébastien , Winum Jean‐Yves
Published: February 2017

Multivalency has impressive effects on (bio)molecular recognition, through the simultaneous presentation of multiple copies of a ligand, which can change a weak millimolar binder into a potent nanomolar one. The implementation of multivalency in enzyme inhibition is rather recent, being exemplified by few serendipitous discoveries, and hitherto relying on the random exploration of new multivalent structures as potential enzyme inhibitors. Here, a straightforward and versatile method is reported that enables the construction of multivalent systems for the inhibition of carbonic anhydrases (CA), widespread enzymes that catalyze a fundamental biochemical reaction. Oxime and hydrazone click‐type bioconjugation techniques were successfully used for the preparation of tetravalent peptide conjugates tethered with sulfonamide CA inhibitors. The enzyme inhibition assays show that multivalent effects were present with these novel compounds, but also reveal various structural effects provided by the scaffolds. The versatility of this approach may facilitate the exploration of structure–activity relationships for other types of enzyme inhibitors.
First Insertions of Carbene Ligands into Ge−N and Si−N Bonds
Authors: Álvarez‐Rodríguez Lucía , Cabeza Javier A. , García‐Álvarez Pablo , Gómez‐Gallego Mar , Merinero Alba D. , Sierra Miguel A.
Published: February 2017

The insertion of carbene ligands into Ge−N (three examples) and Si−N (one example) bonds has been achieved for the first time by treating Fischer carbene complexes (M=W, Cr) with bulky amidinatotetrylenes (E=Ge, Si). These reactions, which start with a nucleophilic attack of the amidinatotetrylene heavier group 14 atom to the carbene C atom, proceed through a stereoselective insertion of the carbene fragment into an E−N bond of the amidinatotetrylene ENCN four‐membered ring, leading to [M(CO)5L] derivatives in which L belongs to a novel family of tetrylene ligands comprising an ECNCN five‐membered ring.
Functionalization of Cyclohexane Derivatives via Oxidative Radical Pathway
Authors: Teng Fan , Cheng Jiang
Published: February 2017

The straightforward functionalization of simple alkanes (simple alkanes refer particularly to cyclohexane derivatives) has been a challenging subject in modern chemistry. However, with the development of oxidative radical reaction, it provided an available and alternative approach to meet the requirement of activating these compounds. In the review, we summarized the recent advances in this field, and the review mainly contained the following four parts: (1) the formation of C—C bonds; (2) the formation of C—N bonds; (3) the formation of C—S bonds and (4) the formation of C—O bonds.
An efficient multistage algorithm for full calibration of the hemodynamic model from BOLD signal responses
Authors: Zambri Brian , Djellouli Rabia , Laleg‐Kirati Taous‐Meriem
Published: February 2017

We propose a computational strategy that falls into the category of prediction/correction iterative‐type approaches, for calibrating the hemodynamic model. The proposed method is used to estimate consecutively the values of the two sets of model parameters. Numerical results corresponding to both synthetic and real functional magnetic resonance imaging measurements for a single stimulus as well as for multiple stimuli are reported to highlight the capability of this computational methodology to fully calibrate the considered hemodynamic model.
Pathways into psychopathology: Modeling the effects of trait emotional intelligence, mindfulness, and irrational beliefs in a clinical sample
Authors: Petrides K. V. , Gómez María G. , Pérez‐González Juan‐Carlos
Published: February 2017

We investigated possible pathways into mental illness via the combined effects of trait emotional intelligence (trait EI), mindfulness, and irrational beliefs. The sample comprised 121 psychiatric outpatients (64.5% males, mean age = 38.8 years) with a variety of formal clinical diagnoses. Psychopathology was operationalized by means of 3 distinct indicators from the Millon Clinical Multi‐Axial Inventory (mild pathology, severe pathology, and clinical symptomatology). A structural equation model confirmed significant direct trait EI and mindfulness effects on irrational beliefs and psychopathology. Trait EI also had a significant indirect effect on psychopathology via mindfulness. Together, the 3 constructs accounted for 44% of the variance in psychopathology. A series of hierarchical regressions demonstrated that trait EI is a stronger predictor of psychopathology than mindfulness and irrational beliefs combined. We conclude that the identified pathways can provide the basis for the development of safe and effective responses to the ongoing mental health and overmedication crises.

Key Practitioners Messages

Self‐perception constructs concerning one's beliefs about oneself have a major impact on the likelihood of developing psychopathological symptoms.

Emotional perceptions captured by trait emotional intelligence were stronger predictors of psychopathology than either or both mindfulness and irrational beliefs in a clinical sample of adults.

If the seed factors of psychopathology are mainly psychological, rather than mainly biological, and given that psychological constructs, like trait emotional intelligence, mindfulness, and irrational beliefs, are amenable to training and optimization, the findings herein provide the impetus for a much needed shift of emphasis from pharmacological to psychological treatments.
Fine needle aspiration cytology of the papillary thyroid carcinoma with a solid component: A cytological and clinical correlation
Authors: Ohashi Ryuji , Murase Yukihiro , Matsubara Miyuki , Watarai Yasuhiko , Igarashi Takehito , Sugitani Iwao , Naito Zenya
Published: February 2017

Background

Solid variant of papillary thyroid carcinoma is a rare subtype of papillary thyroid carcinoma (PTC) containing a solid component (SC), and thus its cytological and clinicopathological features remain elusive. We examined fine needle aspiration (FNA) cytological features of PTC with variable degrees of SC (20‐80% of the tumor)(PTCSC) in comparison to well‐differentiated PTC (WPTC).

Methods

Twenty‐six cases of PTCSC were histologically stratified into major‐SC (SC >50% of the tumor) and minor‐SC (<49%) groups. Pre‐operative FNA smears were compared between major‐SC (n = 11) and minor‐SC (n = 15) groups, and between PTCSC and WPTC (n = 39) groups.

Results

In FNA smears of PTCSC, the presence of cohesive solid nests, trabecular patterns, overlapping, enlarged nuclei, pleomorphism, and distinct nucleolus, and the absence of colloid and psammoma bodies were noted more often than in WPTC, while classical cytological features of PTC, such as nuclear grooves and/or pseudo‐nuclear inclusions, were preserved. There was no significant difference in FNA findings between the major‐SC and minor‐SC groups. The presence of either solid nests or trabecular patterns, and overlapping in FNA smears of PTCSC was associated with a higher recurrence rate of the tumor (P = 0.007 and P < 0.001, respectively).

Conclusion

PTCSC may pre‐operatively be identified by detecting its characteristic cytological features in FNA smears, regardless of the proportion of SC within the tumor. Because clinical outcomes of PTCSC remain undetermined, it is imperative to postulate PTCSC as a differential diagnosis, even when classical nuclear features of PTC are present. Diagn. Cytopathol. 2017;45:391–398. © 2017 Wiley Periodicals, Inc.
Which metal represents the greatest risk to freshwater ecosystem in bohai region of china?
Authors: Su Chao , Lu Yonglong , Johnson Andrew C. , Shi Yajuan , Zhang Meng , Zhang Yueqing , Juergens Monika D. , Jin Xiaowei
Published: February 2017

Metals discharged from industrial effluents, agricultural wastewater, and sewage runoff by rapid urbanization are of concern as contaminants of freshwater ecosystem because of their persistence and high toxicity to aquatic organisms. This study attempted to identify which metal posed the greatest risk to freshwater ecosystem in the Bohai Region, China. The metals arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), zinc (Zn), lead (Pb), nickel (Ni), mercury (Hg), iron (Fe), and manganese (Mn) were compared against norfloxacin and gamma‐hexachlorocyclohexane (lindane). By comparing the median reported environmental and ecotoxicity concentrations, it showed that Cu, Fe, Zn, Mn, and Cr were the top five metals of concern. Of these, Cu was deemed to represent the highest risk and Hg the lowest risk. The risks for all metals were higher than those for norfloxacin and lindane. Almost all the metals except Hg had water concentrations that exceeded levels where ecotoxicity effects had been recorded in the literature. A comparison with the measurements across the rivers suggested that all metals examined had water concentrations about 5‐ to 10‐fold higher than the median values except for Cu, Fe, Cd, and Pb. The Fuyang River, a tributary of the Haihe River Basin, seemed to be the location with the highest metal concentrations. However, comparing the post‐2010 period to 2000–2009, concentrations of all the metals had fallen except for Fe and Mn, so risks have decreased over the last 7 yr with the greatest improvements for Cd and Pb. While metals still pose high risks to freshwater ecosystem in this region, there is encouragement that some control measures are taken into effect.
Surface Defects as a Tool to Solubilize and Functionalize WS2 Nanotubes
Authors: Spetter Dmitri , Hoshyargar Faegheh , Sahoo Jugal Kishore , Tahir Muhammad Nawaz , Branscheid Robert , Barton Bastian , Panthöfer Martin , Kolb Ute , Tremel Wolfgang
Published: February 2017

Layered transition metal dichalcogenides contain a number of crystal defects that significantly change their properties and are beneficial or detrimental for a specific application. We have prepared defect‐rich multiwalled WS2 nanotubes by reductive sulfidization of W18O49 nanowires that were obtained solvothermally from tungsten chloride in different alcohols. The synthesis of the W18O49 nanowires was monitored, and their morphological characteristics (e.g., length, rigidity, and aspect ratio) are described in detail. The effect of the morphology of the nanowires on the synthesis of WS2 nanotubes was investigated in order to obtain WS2 nanotubes that are highly solvent‐dispersible. Dispersions of the WS2 nanotubes in organic solvents are very stable for several days. The nanotubes were easily functionalized with noble metal, metal oxide, and Janus‐type metal@metal oxide nanoparticles. The synthesis of nanowires and nanotubes and the immobilization of the nanoparticles were demonstrated by TEM, high‐resolution TEM (HRTEM) combined with energy‐dispersive X‐ray spectroscopy (EDX), electron diffraction (ED), XRD, and Raman spectroscopy.
Integrated process development of a reactive extraction concept for itaconic acid and application to a real fermentation broth
Authors: Gorden Jannick , Geiser Elena , Wierckx Nick , Blank Lars M. , Zeiner Tim , Brandenbusch Christoph
Published: February 2017

Itaconic acid (IA) has a high potential to be used as a bio‐based platform chemical and its biocatalytic production via fermentation has significantly improved within the last decade. Additionally downstream processing using reactive extraction (RE) was described, potentially enabling a more efficient sustainable bioprocess producing IA. The bottleneck to overcome is the connection of up‐ and downstream processing, caused by lack of biocompatibility of the RE systems and direct application to fermentation broth. Within this study, a biocompatible RE system for IA is defined (pH dependency, extraction mechanism) and used for direct application to a fermentation broth. By optimizing the biocatalyst, the production medium, and the extraction system in an integrated approach, it was possible to define critical parameters that enabled a tuning of the overall bioprocess. With an extraction yield of YIA = 0.80 ± 0.03, IA could be produced as sole carboxylic acid ( = 0.490 mol/kgaq) using a RE system consisting of ethyl oleate as organic solvent and tri‐n‐octylamine as extractant ( = 0.6 mol/kgorg). This work is a proof of concept and demonstrates that by joint consideration of up‐ and downstream processing, optimized bioprocesses can be developed.
Capacity assessment of CO2 storage in deep saline aquifers by mineral trapping and the implications for Songliao Basin, Northeast China
Authors: Jin Chao , Liu Langtao , Li Yiman , Zeng Rongshu
Published: February 2017

Sequestrating CO2 in deep saline aquifers is maybe the most effective option to mitigate CO2 emission. The storage capacity of CO2 is the key factor for site selection before a project is carried out. Most of the existing methods are for assessment of CO2 sequestered by stratigraphic and structural trapping, as well as residual trapping and solubility trapping. In this study, we used a new method that considers CO2 consumption through geochemical reactions with minerals of reservoir rocks, mainly sandstones. Contribution of storage capacity from carbonate mineral mainly refers to calcite is excluded. That is because lifetime of calcite (the whole time from reaction starting to calcite running out) is very short contrast with geological time‐scale or it is a temporary trapping. The geochemical reactions between CO2 and feldspar minerals with thousand‐year lifetime are regarded as the permanent methods for trapping CO2. CO2 consumptions by K‐feldspar, albite, and anorthite are assessed with volume method based on corresponding geochemical reactions. Storage efficiency factor is also considered as one of the most important parameters in the reaction formula and it depends on specific surface area of minerals contacting with formation water and kinetics of precipitation and dissolution of minerals. We assessed the CO2 storage capacity of mineral trapping in Baokang sedimentary system, south Songliao Basin through the detailed analysis of geological data in this area. The calculated results show the total CO2 storage capacity of mineral trapping of the study area is 457.5–5114.5 Mt and the corresponding storage efficiency factor is 1%. The CO2 consumed by albite makes up more than 60% of the total storage capacity and it is about 30% for anorthite.
Potential for the formation of respirable fibers in carbon fiber reinforced plastic materials after combustion
Authors: Eibl S.
Published: February 2017

Fundamental aspects for the thermal decomposition and formation of respirable fragments of carbon fibers are investigated to assess the health hazard of carbon fiber reinforced plastic material after a fire. The influence of temperature (600°C‐900°C)/heat flux (30‐80 kW/m2), time of thermal load (up to 20 minutes), and oxygen exposure is analyzed by means of mass loss and fiber diameter of intermediate modulus and high tenacity fibers with initial diameters of 5 to 7 μm. Various types and concentrations of flame retardants were tested with respect to fiber protection. Epoxy‐based composite specimens (RTM6/G0939) additionally containing aluminum or magnesium hydroxide and/or zinc borate (1‐25 wt% per resin) were analyzed by cone calorimetry. Carbon fiber decomposition increases with combustion/irradiation time and temperature/heat flux, after a threshold temperature (ca 600°C) is exceeded. Critical fiber diameters below 3 μm are reached within minutes and are predominantly observed close to the panel surface in contact with air. Effective fiber protection is achieved by flame retardants acting beyond 600°C, forming thermally resistant layers such as zinc borate. A new field of research is opened identifying flame retardants, which protect carbon fibers in carbon fiber reinforced plastic.
Parameter Optimization for the Electrospinning of La1–xSrxCo1–yFeyO3–δ Fibers for IT‐SOFC Electrodes
Authors: Enrico A. , Aliakbarian B. , Lagazzo A. , Donazzi A. , Botter R. , Perego P. , Costamagna P.
Published: February 2017

La1–xSrxCo1–yFeyO3–δ (LSCF) fibers are synthesized through the single‐needle electrospinning method. The formation of nanofibers is a function of the operating parameters, i.e., rotational speed of the support, solution feeding rate, and operating voltage, which are investigated experimentally in this work. The results show that a rotational speed of 750 rpm, a solution feeding rate of 0.5 mL h−1, and an operating voltage of 17 kV allow to obtain tissues with an average fiber diameter of 0.590 μm and porosity around 50%. The subsequent calcination processes are investigated through thermogravimetric analysis (TGA), which shows exothermic peaks due to solvent evaporation, debinding and perovskite structure formation, and suggest to perform calcination slowly in the temperature range 520–820 K. A fiber calcination process is carried out with a heating rate of 0.3 K min−1. Calcined fibers appear unbroken and visibly shrunk (post‐calcination average diameter 0.31 μm), with a porosity of the calcined tissue of 51%. The morphological chacteristics of the LSCF calcined tissues are very promising for application in intermediate temperature solid oxide fuel cell (IT‐SOFC) electrodes.
Randomized controlled trial of a multisite speech pathology telepractice service providing swallowing and communication intervention to patients with head and neck cancer: Evaluation of service outcomes
Authors: Burns Clare L. , Ward Elizabeth C. , Hill Anne J. , Kularatna Sanjeewa , Byrnes Joshua , Kenny Lizbeth M.
Published: February 2017

Background

The purpose of this study was to present our evaluation of a new speech pathology telepractice service supporting the swallowing and communication management of patients with head and neck cancer.

Methods

A multicenter randomized controlled trial was conducted within a large public cancer service. Referrals from speech pathologists at 3 regional sites (spoke sites) were managed by a specialist clinician from a cancer center (hub site) either via standard care (phone/email support/appointments at the hub site) or a newly established telepractice service (online consultation between the hub site and spoke site).

Results

Eighty‐two referrals (39 for standard care and 43 for telepractice care) were managed. Service efficiency favoring the telepractice model was reported with a significant reduction in the number (p = .004) and duration (p = .024) of contact events required to manage the referrals. Higher consumer and clinician satisfaction was also reported for the telepractice service.

Conclusion

A speech pathology telepractice service benefits both the patient and health provider through higher service efficiency and treatment satisfaction. © 2017 Wiley Periodicals, Inc. Head Neck 39: 932–939, 2017
Prediction on dielectric strength and boiling point of gaseous molecules for replacement of SF6
Authors: Yu Xiaojuan , Hou Hua , Wang Baoshan
Published: February 2017

Developing the environment‐friendly insulation gases to replace sulfur hexafluoride (SF6) has attracted considerable experimental and theoretical attentions but without success. A computational methodology was presented herein for prediction on dielectric strength and boiling point of arbitrary gaseous molecules in the purpose of molecular design and screening. New structure–activity relationship (SAR) models have been established by combining the density‐dependent properties of the electrostatic potential surface, including surface area and the statistical variance of the surface potentials, with the molecular properties including polarizability, electronegativity, and hardness. All the descriptors in the SAR models were calculated using density functional theory. The substitution effect of SF6 by various functional groups was studied systematically. It was found that CF3 is the most effective functional group to improve the dielectric strength due to the large surface area and polarizability. However, all the substitutes exhibit higher boiling points than SF6 because the molecular hardness decreases. The balance between Er and Tb could be achieved by minimizing the local polarity of the molecules. SF5CN and SF5CFO were found to be the potent candidates to replace SF6 in view of their large dielectric strengths and low boiling points. © 2017 Wiley Periodicals, Inc.
Achromatic and Harmonious Colorings of Circulant Graphs
Authors: Dębski Michał , Lonc Zbigniew , Rzążewski Paweł
Published: February 2017

A proper vertex coloring of a graph G is achromatic (respectively harmonious) if every two colors appear together on at least one (resp. at most one) edge. The largest (resp. the smallest) number of colors in an achromatic (resp. a harmonious) coloring of G is called the achromatic (resp. harmonious chromatic) number of G and denoted by (resp. ). For a finite set of positive integers and a positive integer n, a circulant graph, denoted by , is an undirected graph on the set of vertices that has an edge if and only if either or is a member of (where substraction is computed modulo n). For any fixed set , we show that is asymptotically equal to , with the error term . We also prove that is asymptotically equal to , with the error term . As corollaries, we get results that improve, for a fixed k, the previously best estimations on the lengths of a shortest k‐radius sequence over an n‐ary alphabet (i.e., a sequence in which any two distinct elements of the alphabet occur within distance k of each other) and a longest packing k‐radius sequence over an n‐ary alphabet (which is a dual counterpart of a k‐radius sequence).