bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydrogels reinforced with nanoclays with improved response rate
Authors: Djonlagic Jasna , Lancuski Anica , Nikolic Marija S. , Rogan Jelena , Ostojic Sanja , Petrovic Zoran
Published: October 2016

Two series of semiinterpenetrating networks (SIPN) based on linear hydrophilic poly(vinyl alcohol) (PVA) and thermo‐responsive poly(N‐isopropylacrylamide) (PNIPA), physically crosslinked with inorganic clay, are presented. The hydrogels with different crosslinking densities were prepared by varying the content of clay from 1 to 6 wt % and contained linear interpenetrant, PVA in the range of 0.5–1.5 wt %. The effect of clay content on swelling/deswelling behavior and phase transition in PNIPA gels, as well as the feasibility of reinforcing the gels with high molecular weight PVA, were analyzed. The thermal response of hydrogels, followed by DSC, confirmed that the insertion of hydrophilic PVA did not have a significant effect on the onset of the volume phase transition temperature, while the response was faster. The equilibrium degree of swelling of SIPNs and PNIPA hydrogels was in the range of 9–79 and decreased with increasing content of clay. The internal morphology and surface wettability of the hydrogels were investigated by scanning electron microscope analysis and contact angle measurements, respectively. The network structural parameters of the PNIPA and SIPN nanocomposites hydrogels, such as the average molecular weight between crosslinks, Mc, and effective crosslinking density, Ne, were determined by dynamic mechanical analysis. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44535.
Resolving some chronological problems at Nombe rock shelter in the highlands of Papua New Guinea
Authors: DENHAM TIM , MOUNTAIN MARY‐JANE
Published: October 2016

New AMS radiocarbon dating at Nombe rock shelter in Simbu Province, Papua New Guinea confirms human use from c.25500–19600 calBP and corroborates previous chronostratigraphic interpretations for four major periods of cultural deposition. The original conventional radiocarbon dating program was largely undertaken on bone and flowstones, due to the limitations of dating small charcoal fragments in the 1970s and 1980s before the advent of, and widespread access to, AMS dating. Here, 18 new AMS dates on small fragments of charcoal hand‐picked from previously collected sediment samples enable an evaluation that largely confirms previous dating. These findings are significant because they indicate that the chronostratigraphy, at least for the portion of the site redated thus far, is comparatively robust. Primarily, the new dating results indicate the chronostratigraphy for the early and mid‐Holocene, a period crucial for understanding the emergence of agriculture in the highlands, is well preserved at the site.
Amplifying the impact of open access: Wikipedia and the diffusion of science
Authors: Teplitskiy Misha , Lu Grace , Duede Eamon
Published: October 2016

With the rise of Wikipedia as a first‐stop source for scientific information, it is important to understand whether Wikipedia draws upon the research that scientists value most. Here we identify the 250 most heavily used journals in each of 26 research fields (4,721 journals, 19.4M articles) indexed by the Scopus database, and test whether topic, academic status, and accessibility make articles from these journals more or less likely to be referenced on Wikipedia. We find that a journal's academic status (impact factor) and accessibility (open access policy) both strongly increase the probability of it being referenced on Wikipedia. Controlling for field and impact factor, the odds that an open access journal is referenced on the English Wikipedia are 47% higher compared to paywall journals. These findings provide evidence is that a major consequence of open access policies is to significantly amplify the diffusion of science, through an intermediary like Wikipedia, to a broad audience.
Synthesis, Structures, Resolution, and Chiroptical Properties of 1,16‐Diaryl‐Substituted Benzo[5]helicene Derivatives
Authors: Lin Wei‐Bin , Li Meng , Fang Lei , Shen Yun , Chen Chuan‐Feng
Published: October 2016

An efficient route to the synthesis of benzo[5]helicene derivatives functionalized on the interior side of the helix was developed, and resulted in a series of 1,16‐diaryl‐substituted benzo[5]helicene derivatives starting from easily available 7‐methoxytetralone. X‐ray crystal structures showed that the benzo[5]helicene derivatives had highly helical, twisted structures, and could all create hierarchical packing architectures with alternating P and M layers in the solid state. Moreover, seven pairs of enantiomers based on 1,16‐diaryl‐substituted benzo[5]helicene derivatives were also obtained by efficient resolution through HPLC with semipreparative chiral columns. The enantiomers all showed clear mirror‐image circular dichroism (CD) spectra and high specific optical rotations, and their absolute configurations were determined by X‐ray crystallography. Interestingly, a helical nanotubular structure was formed by the self‐assembly of one enantiomer through halogen bonding. Furthermore, the enantiomers were found to have high racemization barriers and thermostability, which might be caused by the introduction of aryl substituents at the C1(C16) position.
Different long‐term trends of extra‐tropical cyclones and windstorms in ERA‐20C and NOAA‐20CR reanalyses
Authors: Befort Daniel J. , Wild Simon , Kruschke Tim , Ulbrich Uwe , Leckebusch Gregor C.
Published: October 2016

NOAA 20th century and ERA‐20C reanalysis datasets are evaluated regarding the representation of extra‐tropical cyclones and windstorms over the Northern and Southern Hemisphere during the respective 6‐month winter seasons. The results indicate substantial differences in low‐frequency variability between the two datasets – especially in the first half of the 20th century – expressed in different signs and/or magnitudes of long‐term trends. This is hampering a reliable analysis of real long‐term trends of cyclone and windstorm activity. However, higher‐frequency variability is in good agreement between both datasets especially for the Northern Hemisphere.
Deriving cloud microphysics from radiometric measurements in the Amazon Basin
Authors: Correia Alexandre L. , Catandi Patricia B.
Published: October 2016

A prototype suite comprised of calibrated radiometric cameras was developed to derive estimates of key cloud properties such as brightness temperature and droplet effective radius, with high spatial and temporal resolution. The system was assembled aboard an airplane to measure shortwave radiation scattered by clouds, and longwave infrared radiation emitted by clouds. This allowed deriving cloud droplet radii in shallow cumuli, with values ranging from about 6 to 14 µm. The measured longwave radiance was inverted using Planck's equation to derive the brightness temperature, with results ranging between −18 °C and +15 °C.
The Functional Independence of Skinner's Verbal Operants: Conceptual and Applied Implications
Authors: Fryling Mitch J.
Published: October 2016

Much has been said about B. F. Skinner's analysis of verbal behavior. This commentary specifically focuses on the functional independence of B. F. Skinner's verbal operants. While researchers have long been interested in this topic, the research literature on this topic has produced mixed results; it has shown that the verbal operants may be both functionally independent and functionally interdependent. This commentary considers the conceptual and applied implications of these mixed findings. The distinction between constructs and events is highlighted, with specific attention to how this distinction relates to the consideration of the verbal operants in behavior analysis. The value of further research on the functional independence of the verbal operants is considered, as well as the type of research studies that might be useful toward developing interventions for individuals with language delays. Copyright © 2016 John Wiley & Sons, Ltd.
Parallel online multi‐wavelength (2D) fluorescence spectroscopy in each well of a continuously shaken microtiter plate
Authors: Ladner Tobias , Beckers Mario , Hitzmann Bernd , Büchs Jochen
Published: October 2016

Small‐scale high‐throughput screening devices are becoming increasingly important in bioprocess development. Conventional dipping probes for process monitoring are often too large to be used in these devices. Thus, optical measurements are often the method of choice. Even some parameters that cannot directly be measured by fluorescence become accessible via sensitive fluorescence dyes. However, not all compounds of interest are measurable by this technique. Recent studies applying multi‐wavelength (2D) fluorescence spectroscopy in combination with chemometrics have shown that information on numerous analytes is obscured by the fluorescence data. Hitherto, this measurement technique has only been available on the scale of stirred tank fermenters. This work introduces a new device for multi‐wavelength (2D) fluorescence spectroscopy in each well of a continuously shaken microtiter plate. Using a combination of spectrograph and CCD detector, the required time per measurement cycle in a 48‐well microtiter plate was 0.5 h. Cultures of Hansenula polymorpha and Escherichia coli are monitored. The concentrations of glycerol, glucose and acetate as well as pH are determined using partial least square (PLS) models. Because a pH‐sensitive fluorescence dye was not required, no dependency of the pKa of a fluorescence dye exists, and measurements in the low pH range can be obtained.
Peptide‐based supramolecular hydrogels for delivery of biologics
Authors: Li Yi , Wang Feihu , Cui Honggang
Published: October 2016

The demand for therapeutic biologics has rapidly grown over recent decades, creating a dramatic shift in the pharmaceutical industry from small molecule drugs to biological macromolecular therapeutics. As a result of their large size and innate instability, the systemic, topical, and local delivery of biologic drugs remains a highly challenging task. Although there exist many types of delivery vehicles, peptides and peptide conjugates have received continuously increasing interest as molecular blocks to create a great diversity of supramolecular nanostructures and hydrogels for the effective delivery of biologics, due to their inherent biocompatibility, tunable biodegradability, and responsiveness to various biological stimuli. In this context, we discuss the design principles of supramolecular hydrogels using small molecule peptides and peptide conjugates as molecular building units, and review the recent effort in using these materials for protein delivery and gene delivery.
DNA‐Templated Synthesis of Perylenediimide Stacks Utilizing Abasic Sites as Binding Pockets and Reactive Sites
Authors: Takada Tadao , Ido Misa , Ashida Akane , Nakamura Mitsunobu , Yamana Kazushige
Published: October 2016

DNA is considered to be a promising biomolecule as a template and scaffold for arranging and organizing functional molecules on the nanoscale. The construction and evaluation of DNAs containing multiple functional molecules that are useful for optoelectronic devices and sensors has been studied. In this paper we report the efficient incorporation of perylenediimide (PDI) units into DNA by using abasic sites both as binding sites and as reactive sites and the construction of PDI stacks within the DNA structure, accomplished through the preorganization of the PDI units in the hydrophobic pocket within the DNA. Our approach could become a valuable method for construction of DNA/chromophore hybrid structures potentially useful for the design of DNA‐based devices and biosensors.
Switch in Cofactor Specificity of a Baeyer–Villiger Monooxygenase
Authors: Beier Andy , Bordewick Sven , Genz Maika , Schmidt Sandy , van den Bergh Tom , Peters Christin , Joosten Henk‐Jan , Bornscheuer Uwe T.
Published: October 2016

Baeyer–Villiger monooxygenases (BVMOs) catalyze the oxidation of ketones to esters or lactones by using molecular oxygen and a cofactor. Type I BVMOs display a strong preference for NADPH. However, for industrial purposes NADH is the preferred cofactor, as it is ten times cheaper and more stable. Thus, we created a variant of the cyclohexanone monooxygenase from Acinetobacter sp. NCIMB 9871 (CHMOAcineto); this used NADH 4200‐fold better than NADPH. By combining structure analysis, sequence alignment, and literature data, 21 residues in proximity of the cofactor were identified and targeted for mutagenesis. Two combinatorial variants bearing three or four mutations showed higher conversions of cyclohexanone with NADH (79 %) compared to NADPH (58 %) as well as specificity. The structural reasons for this switch in cofactor specificity of a type I BVMO are especially a hydrogen‐bond network coordinating the two hydroxy groups of NADH through direct interactions and bridging water molecules.
Sorption‐Enhanced Steam Reforming of Glycerol over Ni–hydrotalcite: Effect of Promotion with Pt
Authors: Dewoolkar Karan D. , Vaidya Prakash D.
Published: October 2016

Sorption‐enhanced steam reforming of glycerol (SESRG) is a promising method for the sustainable production of hydrogen (H2). In this work, composites of Ni and cationic‐modified hydrotalcite (HTlc) were promoted with Pt, thus resulting in two novel hybrid materials Pt‐NiMgHTlc and Pt‐NiCuHTlc. Activity trials for SESRG were performed in a fixed‐bed reactor in the range 673–873 K and it was found that the promotion with Pt improved H2 purity and multi‐cycle durability. The best results were achieved when Pt‐NiCuHTlc was employed at T=823 K: a H2 concentration of 98.7 mol % and adsorption capacity of 1.34 mol CO2/kg sorbent was achieved. When the multi‐cycle performance was tested for 20 cycles, it was found that NiMgHTlc, NiCuHTlc, Pt‐NiMgHTlc, and Pt‐NiCuHTlc were stable for 5, 8, 13, and 18 cycles. Finally, a likely reaction pathway for SESRG over the investigated multifunctional materials was proposed.
Tyrosine‐Based Ionic Liquid Crystals: Switching from a Smectic A to a Columnar Mesophase by Exchange of the Spherical Counterion
Authors: Neidhardt Manuel M. , Wolfrum Manpreet , Beardsworth Stuart , Wöhrle Tobias , Frey Wolfgang , Baro Angelika , Stubenrauch Cosima , Giesselmann Frank , Laschat Sabine
Published: October 2016

Synthetic strategies were developed to prepare l‐tyrosine‐based ionic liquid crystals with structural variations at the carboxylic and phenolic OH groups as well as the amino functionality. Salt metathesis additionally led to counterion variation. The liquid‐crystalline properties were investigated by differential scanning calorimetry (DSC), polarizing optical microscopy (POM) and X‐ray diffraction (WAXS, SAXS). The symmetrical ILC chlorides bearing the same alkyl chain at both the ester and ether but either an acyclic or cyclic guanidinium group displayed enantiotropic SmA2 mesophases with phase widths of 31–88 K irrespective of the head group. It was particularly the replacement of chloride in the acyclic guanidinium ILC by hexafluorophosphate that induced a phase change from SmA2 to Colr. This phase change was attributed to a higher curvature of the interface due to the larger anion, which increased the effective head group cross‐sectional area of the amphiphilic ILC. The unsymmetrical acyclic guanidinium chlorides, bearing a constant C14 ester and variable alkyl chains on the phenolic position, formed enantiotropic SmA2 phases. The derivative with the largest difference in chain lengths, however, displayed a Colr phase, resulting from discoid aggregates of the cone‐shaped guanidinium chloride. The results are discussed in terms of the packing parameters, which indicate that the phase behaviour of the thermotropic tyrosine‐based ILCs shows analogies to those of lyotropic liquid crystals.
Metal‐Free Reaction of ortho‐Carbonylated Alkynyl‐Substituted Arylaldehydes with Common Amines: Selective Access to Functionalized Isoindolinone and Indenamine Derivatives
Authors: Cao Ziping , Zhu Hongbo , Meng Xin , Guan Jun , Zhang Qiang , Tian Laijin , Sun Xuejun , Chen Guang , You Jinmao
Published: October 2016

Herein we describe a reaction of ortho‐carbonylated alkynyl‐substituted arylaldehydes with common primary amines that can provide functionalized isoindolinone and 3‐hydroxylindenamine products in high yields. Depending on the substituent size of primary amines, two distinct reaction pathways were exploited selectively, that are, an initial aza‐conjugate addition followed by hydrogen transfer to access isoindolinone framework and a unique oxa‐conjugate addition followed by Petasis–Ferrier rearrangement to afford indenamine derivatives. In the presence of Et3N, the reaction property of small primary amines was changed, proceeding to afford 3‐hydroxylindenamine derivatives efficiently. These products contain interesting substructures that exist in many natural products and bioactive molecules. The reaction features contain the use of transition‐metal‐free catalysts, simple operation, broad substrate scope, and product diversity.
Arylimido‐Bridged Dinuclear Ti(μ‐NAr)2Ti Scaffold for Alkyne Insertion into the ortho‐C−H Bond of Arylimido Ligands
Authors: Nagae Haruki , Hato Wataru , Kawakita Kento , Tsurugi Hayato , Mashima Kazushi
Published: October 2016

Dinuclear titanium dialkyl complexes bridged by two μ‐arylimido ligands, [CpTi(CH2SiMe3)(μ‐NAr)]2 (Cp=cyclopentadienyl) activated an ortho‐aryl C−H bond of an μ‐arylimido ligand to form a four‐membered titanacycle. The subsequent insertion reaction of 1‐(trimethylsilyl)propyne into a metal–carbon bond of the four‐membered titanacycle yielded the corresponding six‐membered titanacycle. Further ortho‐C−H bond activation of the other μ‐arylimido ligand and an insertion reaction proceeded to give dinuclear titanium complexes with two six‐membered titanacycles. An Eyring plot in the temperature range 130–150 °C revealed activation parameters for the alkenylation reaction, and deuterium‐labeling experiments showed that the C−H bond activation step is the rate determining step. Relative Gibbs free energies of the starting complexes, reaction intermediates, and transition states were calculated by using DFT calculations.
Synthesis and Self‐Assembly of Cyclic 2,7‐Anthrylene Ethynylene 1,3‐Phenylene Ethynylene Trimer with a Planar Conformation
Authors: Takaki Yuta , Ozawa Ryota , Kajitani Takashi , Fukushima Takanori , Mitsui Masaaki , Kobayashi Kenji
Published: October 2016

Cyclic arylene ethynylene hexamer 1, composed of alternating 2,7‐anthrylene ethynylene units and meta‐phenylene ethynylene units, was synthesized. It shows C3 symmetry and possesses a flat and rigid conformation with a large equilateral triangle‐like cavity. Macrocycle 1 self‐associates through π–π stacking interactions between the anthracene‐containing macrocyclic aromatic cores with indefinite‐association constant KE=6980 m−1 in CDCl3 at 303 K. Macrocycle 1 also self‐assembles into π‐stacked nanofibers in the drop‐cast film.
Nanocomposites through the Chemistry of Single‐Source Precursors: Understanding the Role of Chemistry behind the Design of Monolith‐Type Nanostructured Titanium Nitride/Silicon Nitride
Authors: Bechelany Mirna Chaker , Proust Vanessa , Lale Abhijeet , Miele Philippe , Malo Sylvie , Gervais Christel , Bernard Samuel
Published: October 2016

Monolith‐type titanium nitride/silicon nitride nanocomposites, denoted as TiN/Si3N4, have been prepared by a reaction of polysilazanes with a titanium amide precursor, warm pressing of the resultant polytitanosilazanes, and subsequent pyrolysis of the green bodies at 1400 °C. Initially, a series of polytitanosilazanes was synthesized and the role of the chemistry behind their synthesis was studied in detail by using solid‐state NMR spectroscopy, elemental analysis, and molecular‐weight measurements. The intimate relationship between the chemistry and the processability of these precursors is discussed. Polytitanosilazanes display the appropriate requirements for facile processing in solution and as a melt, but they must be treated with liquid ammonia to be adapted for solid‐state processing, that is, warm‐pressing, to design dense and mechanically stable structures after pyrolysis. We provide a comprehensive mechanistic study of the nanocomposite conversion based on solid‐state NMR spectroscopy coupled with thermogravimetric experiments. HRTEM images coupled with XRD and Raman spectroscopy confirmed the unique nanostructural features of the nanocomposites, which appear to be a result of the molecular origin of the materials. The as‐obtained samples are composed of an amorphous Si3N4 matrix, in which TiN nanocrystals are homogeneously formed in situ in the matrix during the process. The hardness and Young moduli were measured and are discussed.
Synthesis of Multivalent Organotellurium Chain‐Transfer Agents by Post‐modification and Their Applications in Living Radical Polymerization
Authors: Fan Weijia , Nakamura Yasuyuki , Yamago Shigeru
Published: October 2016

Functionalized or multivalent organotellurium chain‐transfer agents (CTAs) for living radical polymerization were synthesized by post‐modification, which involved the condensation between a carboxylic‐acid‐functionalized CTA and various amines in excellent yields without affecting the reactive tellurium moiety. The CTAs exhibited high synthetic versatility for radical polymerization and gave structurally well‐controlled polymers, such as multiarmed polymers, from various monomers. Because all new CTAs are easily available on a large scale by simple purification, the current method significantly facilitates macromolecular engineering based on organotellurium‐mediated radical polymerization (TERP).
Development of Axially Chiral Cyclo‐Biaryldiol Ligands with Adjustable Dihedral Angles
Authors: Zhang Pengxiang , Yu Jipan , Peng Fei , Wu Xudong , Jie Jiyang , Liu Can , Tian Hua , Yang Haijun , Fu Hua
Published: October 2016

A new type of axially chiral cyclo‐[1,1′‐biphenyl]‐2,2′‐diol (CYCNOL) ligands with adjustable dihedral angles have been developed by varying the bridge chain length. Eight‐, nine‐ and ten‐membered cyclo‐ligands were prepared and evaluated by using two representative examples: enantioselective additions of diethylzinc to aldehydes and organometallic reagents to enones. The results revealed that the fine regulation of dihedral angles through variation of the bridge chain length was effective in the asymmetric synthesis.
Solving the Hydrogen and Lithium Substructure of Poly(triazine imide)/LiCl Using NMR Crystallography
Authors: Mesch Maria B. , Bärwinkel Kilian , Krysiak Yaşar , Martineau Charlotte , Taulelle Francis , Neder Reinhard B. , Kolb Ute , Senker Jürgen
Published: October 2016

Poly(triazine imide) with incorporated lithium chloride has recently attracted substantial attention due to its photocatalytic activity for water splitting. However, an apparent H/Li disorder prevents the delineation of structure–property relationships, for example, with respect to band‐gap tuning. Herein, we show that through a combination of one‐ and two‐dimensional, multinuclear solid‐state NMR spectroscopy, chemical modelling, automated electron diffraction tomography, and an analysis based on X‐ray pair distribution functions, it is finally possible to resolve the H/Li substructure. In each cavity, one hydrogen atom is bound to a bridging nitrogen atom, while a second one protonates a triazine ring. The two lithium ions within each cavity are positioned between two nitrogen atoms of neighbouring triazine rings. The thereby induced local dipole moments cause slight buckling of the framework and lateral displacements of the Cl− ions at a coherence length below 2 nm. Nevertheless, the average structure conforms to space group P212121. In this way, we demonstrate that, in particular, the above‐mentioned techniques allow for smart interplay in delineating the real structure of PTI/LiCl.
Dioxoiodane Compounds as Versatile Sources for Iodine(I) Chemistry
Authors: Muñiz Kilian , García Belén , Martínez Claudio , Piccinelli Alessandro
Published: October 2016

The general synthesis, isolation and characterization of electrophilic iodine reagents of the general formula R4N[I(O2CAr)2] is reported. These compounds are air‐ and moisture‐stable iodine(I) reagents, which were characterized including X‐ray analysis. They represent conceptually new iodine(I) reagents with anions as stabilizers. These compounds display the expected performance as electrophilic reagents upon interaction with electron‐rich substrates. The performance of these compounds in a total of 47 different reactions of vicinal iodooxygenation of alkenes is studied and some key features on the reagents are revealed.
Copper‐Aβ Peptides and Oxidation of Catecholic Substrates: Reactivity and Endogenous Peptide Damage
Authors: Pirota Valentina , Dell'Acqua Simone , Monzani Enrico , Nicolis Stefania , Casella Luigi
Published: October 2016

The oxidative reactivity of copper complexes with Aβ peptides 1–16 and 1–28 (Aβ16 and Aβ28) against dopamine and related catechols under physiological conditions has been investigated in parallel with the competitive oxidative modification undergone by the peptides. It was found that both Aβ16 and Aβ28 markedly increase the oxidative reactivity of copper(II) towards the catechol compounds, up to a molar ratio of about 4:1 of peptide/copper(II). Copper redox cycling during the catalytic activity induces the competitive modification of the peptide at selected amino acid residues. The main modifications consist of oxidation of His13/14 to 2‐oxohistidine and Phe19/20 to ortho‐tyrosine, and the formation of a covalent His6‐catechol adduct. Competition by the endogenous peptide is rather efficient, as approximately one peptide molecule is oxidized every 10 molecules of 4‐methylcatechol.
D3h‐Symmetrical Shape‐Persistent Macrocycles Consisting of Pyridine–Acetylene–Phenol Conjugates as an Efficient Host Architecture for Saccharide Recognition
Authors: Abe Hajime , Yoneda Tetsuhiro , Ohishi Yuki , Inouye Masahiko
Published: October 2016

Hexagonal shape‐persistent macrocycles (SPMs) consisting of three pyridine and three phenol rings linked with acetylene bonds were developed as a preorganized host for saccharide recognition by push–pull‐type hydrogen bonding. Three tert‐butyl or 2,4,6‐triisopropylphenyl substituents were introduced on the host to suppress self‐aggregation by steric hindrance. In spite of the simple architecture, association constants Ka of the host with alkyl glycoside guests reached the order of 106 m−1 on the basis of UV/Vis titration experiments. This glycoside recognition was much stronger than that in the cases of acyclic equivalent hosts because of the entropic advantage brought by preorganization of the hydrogen‐bonding sites. Solid–liquid extraction and liquid–liquid transport through a liquid membrane were demonstrated by using native saccharides, and much preference to mannose was observed.
Total Synthesis and Functional Evaluation of Fourteen Derivatives of Lysocin E: Importance of Cationic, Hydrophobic, and Aromatic Moieties for Antibacterial Activity
Authors: Kaji Takuya , Murai Motoki , Itoh Hiroaki , Yasukawa Jyunichiro , Hamamoto Hiroshi , Sekimizu Kazuhisa , Inoue Masayuki
Published: October 2016

Lysocin E (1) is a structurally complex 37‐membered depsipeptide comprising 12 amino‐acid residues with an N‐methylated amide and an ester linkage. Compound 1 binds to menaquinone (MK) in the bacterial membrane to exert its potent bactericidal activity. To decipher the biologically important functionalities within this unique antibiotic, we performed a comprehensive structure‐activity relationship (SAR) study by systematically changing the side‐chain structures of l‐Thr‐1, d‐Arg‐2, N‐Me‐d‐Phe‐5, d‐Arg‐7, l‐Glu‐8, and d‐Trp‐10. First, we achieved total synthesis of the 14 new side‐chain analogues of 1 by employing a solid‐phase strategy. We then evaluated the MK‐dependent liposomal disruption and antimicrobial activity against Staphylococcus aureus by 1 and its analogues. Correlating data between the liposome and bacteria experiments revealed that membrane lysis was mainly responsible for the antibacterial functions. Altering the cationic guanidine moiety of d‐Arg‐2/7 to a neutral amide, and the C7‐acyl group of l‐Thr‐1 to the C2 or C11 counterpart decreased the antimicrobial activities four‐ or eight‐fold. More drastically, chemical mutation of d‐Trp‐10 to d‐Ala‐10 totally abolished the bioactivities. These important findings led us to propose the biological roles of the side‐chain functionalities.
Green, Multi‐Gram One‐Step Synthesis of Core–Shell Nanocomposites in Water and Their Catalytic Application to Chemoselective Hydrogenations
Authors: Urayama Teppei , Mitsudome Takato , Maeno Zen , Mizugaki Tomoo , Jitsukawa Koichiro , Kaneda Kiyotomi
Published: October 2016

We devise a new and green route for the multi‐gram synthesis of core–shell nanoparticles (NPs) in one step under organic‐free and pH‐neutral conditions. Simply mixing core and shell metal precursors in the presence of solid metal oxides in water allowed for the facile fabrication of small CeO2‐covered Au and Ag nanoparticles dispersed on metal oxides in one step. The CeO2‐covered Au nanoparticles acted as a highly efficient and reusable catalyst for a series of chemoselective hydrogenations, while retaining C=C bonds in diverse substrates. Consequently, higher environmental compatibility and more efficient energy savings were achieved across the entire process, including catalyst preparation, reaction, separation, and reuse.
State of Bioremediation in Bangladesh: Current Concept and Implementation Compared to Global Approaches
Authors: Noor Rashed , Ahmed Tasnia , Munshi Saurab Kishore
Published: October 2016

Environmental pollution by various recalcitrant molecules, metals, and metalloids has increased during the decades principally due to the effluent discharges, trashes, garbage, oil spills, chemicals, sewages, etc., from the growing industries posing the major health risks along with the possibility of propagation of communicable diseases. To deal with such a vast clump of environmental pollutants, application of bioremediation has long been known as the supreme biotechnological method because of its eco‐friendly nature. However, the applicability of bioremediation is still obscure except some specific fields to many of the developing countries like Bangladesh. Nevertheless, the toxicity caused by the environmental pollutants has been chalked out to some extent in this country whereas a vast field of environmental cleanup is yet to be resolved. In the present review, the global knowledge and practice of bioremediation has been discussed and the areas of bioremediation strategies in context to Bangladesh have been focused.
A novel Tc‐99 m and fluorescence labeled peptide as a multimodal imaging agent for targeting angiogenesis in a murine tumor model
Authors: Kim Myoung Hyoun , Kim Chang Guhn , Kim Seul‐Gi , Kim Dae‐Weung
Published: October 2016

The serine–aspartic acid–valine (SDV) peptide binds specifically to integrin αVβ3. In the present study, we successfully developed a TAMRA–GHEG–ECG–SDV peptide labeled with both Tc‐99 m and TAMRA to target the integrin αVβ3 of tumor cells; furthermore, we evaluated the diagnostic performance of Tc‐99 m TAMRA–GHEG–ECG–SDV as a dual‐modality imaging agent for tumor of the murine model. TAMRA–GHEG–ECG–SDV was synthesized using Fmoc solid‐phase peptide synthesis. Radiolabeling of TAMRA–GHEG–ECG–SDV with Tc‐99 m was done using ligand exchange methods. Labeling stability and cytotoxicity studies were performed. Gamma camera imaging, biodistribution and ex vivo imaging studies were performed in murine models with HT‐1080 and HT‐29 tumors. A tumor tissue slide was prepared and analyzed using confocal microscopy. After radiolabeling procedures with Tc‐99 m, the Tc‐99 m TAMRA–GHEG–ECG–SDV complexes were prepared in high yield (>99%). In the gamma camera imaging study, a substantial uptake of Tc‐99 m TAMRA–GHEG–ECG–SDV into HT‐1080 tumor (integrin αVβ3 positive) and low uptake of Tc‐99 m TAMRA–GHEG–ECG–SDV into HT‐29 tumor (integrin αVβ3 negative) were demonstrated. A competition study revealed that HT‐1080 tumor uptake was effectively blocked by the co‐injection of an excess concentration of SDV. Specific uptake of Tc‐99 m TAMRA–GHEG–ECG–SDV was confirmed by biodistribution, ex vivo imaging and confocal microscopy studies. Our in vivo and in vitro studies revealed substantial uptake of Tc‐99 m TAMRA–GHEG–ECG–SDV in the integrin αVβ3‐positive tumor. Tc‐99 m TAMRA–GHEG–ECG–SDV could be a good candidate for a dual‐modality imaging agent targeting tumor angiogenesis. Copyright © 2016 John Wiley & Sons, Ltd.
Cancer Cytopathology: 20 years of advancing the field of pancreaticobiliary cytopathology
Authors: Pitman Martha Bishop
Published: October 2016

The past 20 years in cytopathology have demonstrated tremendous growth and evolution in the cytopathology of organs located below the diaphragm, with much of the progress centering on the pancreas. Cancer Cytopathology has been at the forefront of reporting advances in the field of pancreaticobiliary cytology, especially for the diagnosis of pancreatic cysts.
Cytohistologic correlation of recurrent urothelial carcinoma detected in urinary diversion specimens
Authors: Xing Juan , Roy Somak , Monaco Sara E. , Pantanowitz Liron
Published: October 2016

BACKGROUND

Urinary diversion specimens from patients who undergo radical cystectomy are often submitted for urine cytology to screen for recurrent urothelial carcinoma. The objective of the current study was to investigate the frequency and cytohistologic features of cancer recurrence in diversion urine specimens.

METHODS

A 10‐year retrospective review of archival urinary diversion specimens was conducted. For abnormal cytology cases, cytology slides were reviewed, and their cytomorphology and available corresponding histopathology were documented.

RESULTS

In total, 679 diversion urine cytology specimens were identified, of which 39 specimens from 25 patients (5.7 %) had abnormal cytology diagnoses. Seven of 25 patients (28%) had postcystectomy surgical follow‐up, and 5 of them manifested with local recurrence. Among the patients who had local recurrence, 3 (60%) developed lymph node and distant metastases and subsequently died. Sites of tumor recurrence included anastomoses in 4 of 5 patients and the penile urethra in 1 of 5 patients. The diversion urine cytology slides in patients who had carcinoma revealed scant, well preserved urothelial cells either alone or in clusters with high‐grade features, including eccentrically located, enlarged, hyperchromatic nuclei; irregular nuclear borders; and high nuclear‐to‐cytoplasmic ratios.

CONCLUSIONS

The current data demonstrate that abnormal cytology in urinary diversion specimens is rare but, when present, can help to detect recurrent urothelial carcinoma. Careful examination of these specimens is warranted to screen for features of high‐grade urothelial carcinoma among a degenerated cellular and sometimes inflammatory background. Cancer Cytopathol 2017;125:120–127. © 2016 American Cancer Society.
Safety, Tolerability, and Pharmacokinetics of ARC‐520 Injection, an RNA Interference‐Based Therapeutic for the Treatment of Chronic Hepatitis B Virus Infection, in Healthy Volunteers
Authors: Schluep Thomas , Lickliter Jason , Hamilton James , Lewis David L. , Lai Ching‐Lung , Lau Johnson YN , Locarnini Stephen A. , Gish Robert G. , Given Bruce D.
Published: October 2016

ARC‐520 Injection, an RNA interference drug for the treatment of hepatitis B that targets cccDNA‐derived viral mRNA transcripts with high specificity, effectively reduces the production of viral proteins and HBV DNA. In this phase 1 randomized, double‐blind, placebo‐controlled study, 54 healthy volunteers (half male, half female) received a single, intravenous dose of 0.01–4.0 mg/kg ARC‐520 Injection (n = 36) or placebo (n = 18). Assessments included safety, tolerability, pharmacokinetics, and pharmacodynamics (cytokines and complement). Pharmacokinetics of the siRNA and peptide excipient components contained in ARC‐520 Injection showed a relatively short half‐life of 3–5 and 8–10 hours, respectively. Dose exposure linearity was demonstrated within the dose range. ARC‐520 Injection was well tolerated, with adverse‐event frequency the same as placebo and no serious adverse events. ARC‐520 Injection was initially found to induce histamine release through mast cell degranulation, resulting in 2 moderate hypersensitivity reactions. However, after initiation of pretreatment with oral antihistamine, no further hypersensitivity reactions occurred. Low‐level, transient complement induction and sporadic, mild, and transient elevations of several cytokines were observed but not associated with any symptoms. ARC‐520 Injection showed a favorable tolerability profile in this single‐dose study in healthy volunteers. Oral antihistamine pretreatment is recommended in the future to offset mast cell degranulation stimulation.
Catalyst and Process Design for the Continuous Manufacture of Rare Sugar Alcohols by Epimerization–Hydrogenation of Aldoses
Authors: Lari Giacomo M. , Gröninger Olivier G. , Li Qiang , Mondelli Cecilia , López Núria , Pérez‐Ramírez Javier
Published: October 2016

Sugar alcohols are applied in the food, pharmaceutical, polymer, and fuel industries and are commonly obtained by reduction of the corresponding saccharides. In view of the rarity of some sugar substrates, epimerization of a readily available monosaccharide has been proposed as a solution, but an efficient catalytic system has not yet been identified. Herein, a molybdenum heteropolyacid‐based catalyst is developed to transform glucose, arabinose, and xylose into less‐abundant mannose, ribose, and lyxose, respectively. Adsorption of molybdic acid onto activated carbon followed by ion exchange to the cesium form limits leaching of the active phase, which greatly improves the catalyst stability over 24 h on stream. The hydrogenation of mixtures of epimers is studied over ruthenium catalysts, and it is found that the precursor to the desired polyol is advantageously converted with faster kinetics. This is explained by density functional theory on the basis of its more favorable adsorption on the metal surface and the lower energy barrier for the addition of a hydrogen atom to the primary carbon atom. Finally, different designs for a continuous process for the conversion of glucose into mannitol are studied, and it is uncovered that two reactors in series with one containing the epimerization catalyst and the other containing a mixture of the epimerization and hydrogenation catalysts increases the mannitol/sorbitol ratio to 1.5 from 1 for a single mixed‐bed reactor. This opens a prospective route to the efficient valorization of renewables to added‐value chemicals.
Performance optimization of duty‐cycled MAC in delay‐energy constrained sensor network under uniform and nonuniform traffic generation
Authors: Doudou Messaoud , Barcelo‐Ordinas Jose M. , Djenouri Djamel , Badache Nadjib , Garcia‐Vidal Jorge
Published: October 2016

Duty‐cycle at the media access control (MAC) layer plays a key role in energy savings and network lifetime extension. It consists in putting a node's radio in the sleep state as soon as it has no communication activity. Traditional wireless sensor network MAC protocols are designed with short duty‐cycles at the cost of long delays. Careful design is required for joint energy‐delay constrained applications, where the optimal parameters should be thoroughly derived. The present paper deals with this issue and mathematically derives optimal values of key MAC parameters under low data rate applications for 3 well‐known duty‐cycled MAC protocols, WiseMAC, SCP‐MAC, and LMAC as representatives of 3 MAC protocol categories, respectively, preamble‐sampling, slotted contention‐based, and frame‐based. The analysis provides also the optimum traffic sampling rate that guarantees the minimum energy consumption. It shows the role of these parameters in achieving the targeted end‐to‐end delay constraints under network models with uniform traffic generation, for ring and grid topologies. As a second contribution, the model is extended to nonuniform traffic scenarios, where a certain percentage of deployed nodes are relays whose role is to balance traffic forwarding and save the overall network energy. The results reveal that different optimal internal MAC parameters and traffic generation rates can be found for different configurations of relay nodes deployment, which achieve minimal network energy consumption while satisfying the application required end‐to‐end delay threshold.
Thalamic neuronal specification and early circuit formation
Authors: Gezelius Henrik , López‐Bendito Guillermina
Published: October 2016

The thalamus is a central structure of the brain, primarily recognized for the relay of incoming sensory and motor information to the cerebral cortex but also key in high order intracortical communication. It consists of glutamatergic projection neurons organized in several distinct nuclei, each having a stereotype connectivity pattern and functional roles. In the adult, these nuclei can be appreciated by architectural boundaries, although their developmental origin and specification is only recently beginning to be revealed. Here, we summarize the current knowledge on the specification of the distinct thalamic neurons and nuclei, starting from early embryonic patterning until the postnatal days when active sensory experience is initiated and the overall system connectivity is already established. We also include an overview of the guidance processes important for establishing thalamocortical connections, with emphasis on the early topographical specification. The extensively studied thalamocortical axon branching in the cortex is briefly mentioned; however, the maturation and plasticity of this connection are beyond the scope of this review. In separate chapters, additional mechanisms and/or features that influence the specification and development of thalamic neurons and their circuits are also discussed. Finally, an outlook of future directions is given. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 77: 830–843, 2017
Optimization of an online heart‐cutting multidimensional gas chromatography clean‐up step for isotopic ratio mass spectrometry and simultaneous quadrupole mass spectrometry measurements of endogenous anabolic steroid in urine
Authors: Casilli Alessandro , Piper Thomas , de Oliveira Fábio Azamor , Padilha Monica Costa , Pereira Henrique Marcelo , Thevis Mario , de Aquino Neto Francisco Radler
Published: October 2016

Measuring carbon isotope ratios (CIRs) of urinary analytes represents a cornerstone of doping control analysis and has been particularly optimized for the detection of the misuse of endogenous steroids. Isotope ratio mass spectrometry (IRMS) of appropriate quality, however, necessitates adequate purities of the investigated steroids, which requires extensive pre‐analytical sample clean‐up steps due to both the natural presence of the target analytes and the high complexity of the matrix. In order to accelerate the sample preparation and increase the automation of the process, the use of multidimensional gas chromatography (MDGC) prior to IRMS experiments, was investigated. A well‐established instrumental configuration based on two independent GC ovens and one heart‐cutting device was optimized. The first dimension (1D) separation was obtained by a non‐polar column which assured high efficiency and good loading capacity, while the second dimension (2D), based on a mid‐polar stationary phase, provided good selectivity. A flame ionization detector monitored the 1D, and the 2D was simultaneously recorded by isotope ratio and quadrupole mass spectrometry. The assembled MDGC set‐up was applied for measuring testosterone, 5α‐ and 5β‐androstanediol, androsterone, and etiocholanolone as target compounds and pregnanediol as endogenous reference compound. The urine sample were pretreated by conventional sample preparation steps comprising solid‐phase extraction, hydrolysis, and liquid‐liquid extraction. The extract obtained was acetylated and different aliquots were injected into the MDGC system. Two high performance liquid chromatography steps, conventionally adopted prior to CIR measurements, were replaced by the MDGC approach. The obtained values were consistent with the conventional ones. Copyright © 2016 John Wiley & Sons, Ltd.
Nonneuronal roles for the reelin signaling pathway
Authors: Khialeeva Elvira , Carpenter Ellen M.
Published: October 2016

The reelin signaling pathway has been established as an important regulator of cell migration during development of the central nervous system, and disruptions in reelin signaling alter the positioning of many types of neurons. Reelin is a large extracellular matrix glycoprotein and governs cell migration through activation of multiple intracellular signaling events by means of the receptors ApoE receptor 2 (ApoER2) and very low density lipoprotein receptor (VLDLR), and the intracellular adaptor protein Disabled‐1 (Dab1). Earlier studies reported expression of reelin in nonneuronal tissues, but the functions of this signaling pathway outside of the nervous system have not been studied until recently. A large body of evidence now suggests that reelin functions during development and disease of multiple nonneuronal tissues. This review addresses recent advances in the field of nonneuronal reelin signaling. Developmental Dynamics 246:217–226, 2017. © 2016 Wiley Periodicals, Inc.
Nonmotorized recreation and motorized recreation in shrub‐steppe habitats affects behavior and reproduction of golden eagles (Aquila chrysaetos)
Authors: Spaul Robert J. , Heath Julie A.
Published: October 2016

Different forms of outdoor recreation have different spatiotemporal activity patterns that may have interactive or cumulative effects on wildlife through human disturbance, physical habitat change, or both. In western North America, shrub‐steppe habitats near urban areas are popular sites for motorized recreation and nonmotorized recreation and can provide important habitat for protected species, including golden eagles. Our objective was to determine whether recreation use (i.e., number of recreationists) or recreation features (e.g., trails or campsites) predicted golden eagle territory occupancy, egg‐laying, or the probability a breeding attempt resulted in ≥1 offspring (nest survival). We monitored egg‐laying, hatching and fledging success, eagle behavior, and recreation activity within 23 eagle territories near Boise, Idaho, USA. Territories with more off‐road vehicle (ORV) use were less likely to be occupied than territories with less ORV use (β = −1.6, 85% CI: −2.8 to −0.8). At occupied territories, early season pedestrian use (β = −1.6, 85% CI: −3.8 to −0.2) and other nonmotorized use (β = −3.6, 85% CI: −10.7 to −0.3) reduced the probability of egg‐laying. At territories where eagles laid eggs, short, interval‐specific peaks in ORV use were associated with decreased nest survival (β = −0.5, 85% CI: −0.8 to −0.2). Pedestrians, who often arrived near eagle nests via motorized vehicles, were associated with reduced nest attendance (β = −11.9, 85% CI: −19.2 to −4.5), an important predictor of nest survival. Multiple forms of recreation may have cumulative effects on local populations by reducing occupancy at otherwise suitable territories, decreasing breeding attempts, and causing nesting failure. Seasonal no‐stopping zones for motorized vehicles may be an alternative to trail closures for managing disturbance. This study demonstrates the importance of considering human disturbance across different parts of the annual cycle, particularly where multiple forms of recreation have varying spatiotemporal use patterns that create human–wildlife interactions.