bluuebunny/crossref_metadata_2025 huggingface dataset:
Neural correlates of Korean proverb processing: A functional magnetic resonance imaging study
Authors: Yi You Gyoung , Kim Dae Yul , Shim Woo Hyun , Oh Joo Young , Kim Sung Hyun , Kim Ho Sung
Published: September 2017

Introduction

The Korean language is based on a syntactic system that is different from other languages. This study investigated the processing area of the Korean proverb in comparison with the literal sentence using functional magnetic resonance imaging. In addition, the effect of opacity and transparency of proverbs on the activation pattern, when familiarity is set to the same condition, was also examined.

Methods

The experimental stimuli included 36 proverbs and 18 literal sentences. A cohort of 15 healthy participants silently read each sentence for 6 s. A total of 18 opaque proverbs, 18 transparent proverbs, and 18 literal sentences were presented pseudo‐randomly in one of three predesigned sequences.

Results

Compared with the literal sentences, a significant activation pattern was observed in the left hemisphere, including the left inferior frontal gyrus, in association with the proverbs. Compared with the transparent proverbs, opaque proverbs elicited more activation in the right supramarginal gyrus and precuneus.

Conclusions

Our study confirmed that the left inferior frontal gyrus mediates the retrieval and/or selection of semantic knowledge in the Korean language. The present findings indicated that the right precuneus and the right supramarginal gyrus may be involved in abstract language processing.
Enzymatic Addition of Alcohols to Terpenes by Squalene Hopene Cyclase Variants
Authors: Kühnel Lisa C. , Nestl Bettina M. , Hauer Bernhard
Published: September 2017

Squalene–hopene cyclases (SHCs) catalyze the polycyclization of squalene into a mixture of hopene and hopanol. Recently, amino‐acid residues lining the catalytic cavity of the SHC from Alicyclobacillus acidocaldarius were replaced by small and large hydrophobic amino acids. The alteration of leucine 607 to phenylalanine resulted in increased enzymatic activity towards the formation of an intermolecular farnesyl–farnesyl ether product from farnesol. Furthermore, the addition of small‐chain alcohols acting as nucleophiles led to the formation of non‐natural ether‐linked terpenoids and, thus, to significant alteration of the product pattern relative to that obtained with the wild type. It is proposed that the mutation of leucine at position 607 may facilitate premature quenching of the intermediate by small alcohol nucleophiles. This mutagenesis‐based study opens the field for further intermolecular bond‐forming reactions and the generation of non‐natural products.
Incidence and outcome of infective endocarditis following percutaneous versus surgical pulmonary valve replacement
Authors: Lluri Gentian , Levi Daniel S. , Miller Emily , Hageman Abbie , Sinha Sanjay , Sadeghi Soraya , Reemtsen Brian , Laks Hillel , Biniwale Reshma , Salem Morris , Fishbein Gregory A. , Aboulhosn Jamil
Published: September 2017

Objectives

To provide a comparison of the outcome of infective endocarditis (IE) in patients undergoing transcatheter pulmonary valve replacement (TPVR) versus surgical pulmonary valve replacement (SPVR).

Background

Although TPVR is thought to be associated with a higher risk of IE than SPVR, there is paucity of data to support this.

Methods

Patients who underwent TPVR or SPVR at UCLA between October 2010 and September 2016 were included and retrospectively analyzed.

Results

Three hundred forty‐two patients underwent PVR at UCLA including 134 SPVR and 208 TPVR. Patients undergoing TPVR were more likely to have had a history of endocarditis than those undergoing SPVR (5.3% vs. 0.7%, P = 0.03) and a right ventricle to pulmonary artery (RV to PA) conduit (37% vs. 17%, P = 0.0001). Two SPVR and seven TPVR patients developed IE with a 4‐year freedom from endocarditis of 94.0% in the SPVR versus 84% in the TPVR group (P = 0.13). In patients who underwent TPVR and developed endocarditis, the mean gradient across the RVOT prior to intervention was higher (28.1 ± 4.5 vs. 17.4 ± 0.6 mmHg, P = 0.02) and were more likely to have a conduit (71% vs. 36%, P = 0.049).

Conclusions

In this study, patients undergoing TPVR were not at a higher risk of IE than patients undergoing SPVR. TPVR patients were more likely to have had a prior history of IE and RV‐PA conduit. The patients at highest risk were those with stenotic RV to PA conduits who were treated with TPVR.
Organosilica Nanotube Templates: One‐Pot Synthesis of Carbon‐Modified Polymeric Carbon Nitride Nanorods for Photocatalysis
Authors: Li Mei , Wang Hua , Li Xiaobo , Zhang Shengbo , Han Jinyu , Masters Anthony F. , Maschmeyer Thomas , Liu Xiao
Published: September 2017

Polymeric carbon nitride (PCN) nanorods with surface carbon modifications were prepared in a one‐step procedure by using phenylene‐bridged organosilica nanotubes as structure‐directing templates. The carbon‐modified PCN nanorods demonstrated enhanced activity in photocatalytic hydrogen production and the degradation of methyl orange relative to conventional bulk PCN and PCN nanorod templated from pure silica nanotube. The enhancement is attributed to the nanorod structure and the formation of carbon nitride carbon heterojunctions, which facilitate photogenerated charge separation and migration.
Functionalized Ultrasmall Fluorinated Graphene with High NIR Absorbance for Controlled Delivery of Mixed Anticancer Drugs
Authors: Gong Peiwei , Zhao Qiao , Dai Dujuan , Zhang Shumiao , Tian Zhenzhen , Sun Lu , Ren Jiashuo , Liu Zhe
Published: September 2017

Fluorinated graphene (FG) possess distinctively novel properties different from graphene and is suitable for many biomedical applications. However, the hydrophobic nature and inert properties of FG limit its further application as a biological material. Here we show the preparation of nano‐sized FG (ca. 60 nm) that exhibits high NIR absorbance for photothermal therapy. In order to make it stable in physiological solutions, the FG is enriched with oxygen and followed by covalent binding with chitosan as a novel pH‐responsive nanocarrier. Furthermore, controlled loading of two anticancer drugs, doxorubicin (DOX) and camptothecin (CPT) has been realized and the functionalized ultrasmall FG shows remarkably high cytotoxicity toward Hela cancer cells compared to that loaded with either CPT or DOX only. This work established nano‐sized FG as a novel photothermal agent due to its small size and can be used a stimulus‐responsive nanocarrier for mixed drug delivery and combined therapy.
Electrocatalytic Azide Oxidation Mediated by a Rh(PNP) Pincer Complex
Authors: Rebreyend Christophe , Gloaguen Yann , Lutz Martin , van der Vlugt Jarl Ivar , Siewert Inke , Schneider Sven , de Bruin Bas
Published: September 2017

One‐electron oxidation of the rhodium(I) azido complex [Rh(N3)(PNP)] (5), bearing the neutral, pyridine‐based PNP ligand 2,6‐bis(di‐tert‐butylphosphinomethyl)pyridine, leads to instantaneous and selective formation of the mononuclear rhodium(I) dinitrogen complex [Rh(N2)(PNP)]+ (9+). Interestingly, complex 5 also acts as a catalyst for electrochemical N3− oxidation (Ep≈−0.23 V vs. Fc+/0) in the presence of excess azide. This is of potential relevance for the design of azide‐based and direct ammonia fuel cells, expelling only harmless dinitrogen as an exhaust gas.
Different and Often Opposing Forces Drive the Encapsulation and Multiple Exterior Binding of Charged Guests to a M4L6 Supramolecular Vessel in Water
Authors: Sgarlata Carmelo , Mugridge Jeffrey S. , Pluth Michael D. , Zito Valeria , Arena Giuseppe , Raymond Kenneth N.
Published: September 2017

The supramolecular assembly [Ga4L6]12− acts as a nanoscale flask to mediate the reactivity of encapsulated reactive guests and also functions as a catalyst to carry out enzyme‐like chemical transformations. The guest binding to the interior cavity and exterior of this host is difficult to untangle because multiple equilibria occur in solution, and only when refining simultaneously data obtained from different techniques, such as NMR, UV/Vis, and calorimetry, can the accurate solution thermodynamics of these host–guest systems be determined. This study reports the driving forces for the inclusion and stepwise exterior guest binding of different aliphatic quaternary ammonium guests to the [Ga4L6]12− assembly. Encapsulation into the host cavity was found to be an entropy‐driven process, whereas exterior ion association is driven either by enthalpically favorable attractive forces or by the entropy gain due to desolvation, depending on guest size and character. The analysis of the energetics of reaction may help predicting and understanding the intimate role and contribution of the transition state in those rate‐accelerated reactions involving this supramolecular assembly as an enzyme‐like molecular flask.
Functionalization of 3‐Iridacyclopentenes
Authors: Gómez Margarita , Rendón Nuria , Álvarez Eleuterio , Mereiter Kurt , Poveda Manuel L. , Paneque Margarita
Published: September 2017

Members of a series of iridacyclopentenes of composition [TpMe2Ir(k2‐C,C‐CH2CR′=CRCH2)(CO)] (TpMe2=hydrotris(3,5‐dimethylpyrazolyl)borate; R=R′=H,1; R=Me, R′=H,2; R=R′=Me,3) have been subjected to common organic chemistry procedures for hydrogenation, cyclopropanation, epoxidation, water addition through hydroboration,cis‐dihydroxylation, and ozonolysis. The stability of metallacycles1–3, imparted by the presence of the co‐ligands TpMe2and CO, directs the reactivity towards the C=C double bonds, and furthermore the stereochemistry of the products formed is strongly dictated by the steric demands of the TpMe2ligand. While the products obtained in some of the above‐mentioned reactions are the expected ones from an organic chemistry point of view, in other cases the results differ from the outcomes of similar reactions carried out with the all‐carbon counterparts.
Syntheses, Properties, and Catalytic Activities of Metal(II) Complexes and Free Bases of Redox‐Switchable 20π, 19π, and 18π 5,10,15,20‐Tetraaryl‐5,15‐diazaporphyrinoids
Authors: Sudoh Keisuke , Satoh Takaharu , Amaya Toru , Furukawa Ko , Minoura Mao , Nakano Haruyuki , Matano Yoshihiro
Published: September 2017

In spite of significant advances in redox‐active porphyrin‐based materials and catalysts, little attention has been paid to 20π and 19π porphyrins because of their instability in air. Here we report the meso‐modification of 5,10,15,20‐tetraarylporphyrin with two nitrogen atoms, which led to redox‐switchable 20π, 19π, and 18π 5,10,15,20‐tetraaryl‐5,15‐diazaporphyrinoids (TADAPs). Three kinds of metal(II) complexes and free bases of TADAP were prepared by the metal‐templated annulation of the corresponding metal‐bis(dipyrrin) complexes. The inductive and resonance effects of the meso‐nitrogen atoms on the aromatic, optical, electrochemical, and magnetic properties of the entire TADAP π‐systems were assessed by using various spectroscopic measurements and density functional theory calculations. The aromaticity and π–π* electronic transition energies of the TADAPs varied considerably, and were shown to be dependent on the oxidation states of the π‐systems. In contrast to the isoelectronic 5,10,15,20‐tetraarylporphyrin derivatives, the 20π and 19π TADAPs were chemically stable under air. In particular, the 19π TADAP radical cations were extremely stable towards dioxygen, moisture, and silica gel. This reflected the low‐lying singly occupied molecular orbitals of their π‐systems and the efficient delocalization of their unshared electron spin. The capability of MgTADAP to catalyze aerobic biaryl formation from aryl Grignard reagents was demonstrated, which presumably involved a 19π/20π redox cycle.
Highly K+‐Selective Fluorescent Probes for Lifetime Sensing of K+ in Living Cells
Authors: Schwarze Thomas , Mertens Monique , Müller Peter , Riemer Janine , Wessig Pablo , Holdt Hans‐Jürgen
Published: September 2017

The new K+‐selective fluorescent probes 1 and 2 were obtained by CuI‐catalyzed 1,3‐dipolar azide alkyne cycloaddition (CuAAC) reactions of an alkyne‐substituted [1,3]dioxolo[4,5‐f][1,3]benzodioxole (DBD) ester fluorophore with azido‐functionalized N‐phenylaza‐18‐crown‐6 ether and N‐(o‐isopropoxy) phenylaza‐18‐crown‐6 ether, respectively. Probes 1 and 2 allow the detection of K+ in the presence of Na+ in water by fluorescence enhancement (2.2 for 1 at 2000 mm K+ and 2.5 for 2 at 160 mm K+). Fluorescence lifetime measurements in the absence and presence of K+ revealed bi‐exponential decay kinetics with similar lifetimes, however with different proportions changing the averaged fluorescence decay times (τf(av)). For 1 a decrease of τf(av) from 12.4 to 9.3 ns and for 2 an increase from 17.8 to 21.8 ns was observed. Variation of the substituent in ortho position of the aniline unit of the N‐phenylaza‐18‐crown‐6 host permits the modulation of the Kd value for a certain K+ concentration. For example, substitution of H in 1 by the isopropoxy group (2) decreased the Kd value from >300 mm to 10 mm. 2 was chosen for studying the efflux of K+ from human red blood cells (RBC). Upon addition of the Ca2+ ionophor ionomycin to a RBC suspension in a buffer containing Ca2+, the fluorescence of 2 slightly rose within 10 min, however, after 120 min a significant increase was observed.
Dichloro‐Cycloazatriphosphane: The Missing Link between N2P2 and P4 Ring Systems in the Systematic Development of NP Chemistry
Authors: Bresien Jonas , Hinz Alexander , Schulz Axel , Suhrbier Tim , Thomas Max , Villinger Alexander
Published: September 2017

A dichloro‐cycloazatriphosphane that incorporates a cyclic NP3 backbone could be synthesized using knowledge gained from the chemistry of N2P2 and P4 ring systems. It fills the gap between the congeneric compounds [ClP(μ‐NR)]2 and [ClP(μ‐PR)]2 (R=sterically demanding substituent), and thus contributes to the systematic development of nitrogen–phosphorus chemistry in general. The title compound was studied with respect to its formation via a labile aminodiphosphene, which readily underwent different rearrangement reactions depending on the solvent. All compounds were fully characterized by experimental and computational methods.
Evaluating the networking characteristics of the Cray XC‐40 Intel Knights Landing‐based Cori supercomputer at NERSC
Authors: Doerfler Douglas , Austin Brian , Cook Brandon , Deslippe Jack , Kandalla Krishna , Mendygral Peter
Published: September 2017

There are many potential issues associated with deploying the Intel Xeon PhiTM (code named Knights Landing [KNL]) manycore processor in a large‐scale supercomputer. One in particular is the ability to fully utilize the high‐speed communications network, given that the serial performance of a Xeon PhiTM core is a fraction of a Xeon®core. In this paper, we take a look at the trade‐offs associated with allocating enough cores to fully utilize the Aries high‐speed network versus cores dedicated to computation, eg, the trade‐off between MPI and OpenMP. In addition, we evaluate new features of Cray MPI in support of KNL, such as internode optimizations. We also evaluate one‐sided programming models such as Unified Parallel C. We quantify the impact of the above trade‐offs and features using a suite of National Energy Research Scientific Computing Center applications.
Interaction of Ester‐Functionalized Ionic Liquids with Atomically‐Defined Cobalt Oxides Surfaces: Adsorption, Reaction and Thermal Stability
Authors: Xu Tao , Waehler Tobias , Vecchietti Julia , Bonivardi Adrian , Bauer Tanja , Schwegler Johannes , Schulz Peter S. , Wasserscheid Peter , Libuda Joerg
Published: September 2017

Hybrid materials consisting of ionic liquid (ILs) films on supported oxides hold a great potential for applications in electronic and energy materials. In this work, we have performed surface science model studies scrutinizing the interaction of ester‐functionalized ILs with atomically defined Co3O4(111) and CoO(100) surfaces. Both supports are prepared under ultra‐high vacuum (UHV) conditions in form of thin films on Ir(100) single crystals. Subsequently, thin films of three ILs, 3‐butyl‐1‐methyl imidazolium bis(trifluoromethyl‐sulfonyl) imide ([BMIM][NTf2]), 3‐(4‐methoxyl‐4‐oxobutyl)‐1‐methylimidazolium bis(trifluoromethyl‐sulfonyl) imide ([MBMIM][NTf2]), and 3‐(4‐isopropoxy‐4‐oxobutyl)‐1‐methylimidazolium bis(trifluoromethyl‐sulfonyl) imide ([IPBMIM][NTf2]), were deposited on these surfaces by physical vapor deposition (PVD). Time‐resolved and temperature‐programmed infrared reflection absorption spectroscopy (TR‐IRAS, TP‐IRAS) were applied to monitor in situ the adsorption, film growth, and thermally induced desorption. By TP‐IRAS, we determined the multilayer desorption temperature of [BMIM][NTf2] (360±5 K), [MBMIM][NTf2] (380 K) and [IPBMIM][NTf2] (380 K). Upon deposition below the multilayer desorption temperature, all three ILs physisorb on both cobalt oxide surfaces. However, strong orientation effects are observed in the first monolayer, where the [NTf2]− ion interacts with the surface through the SO2 groups and the CF3 groups point towards the vacuum. For the two functionalized ILs, the [MBMIM]+ and [IPBMIM]+ interact with the surface Co2+ ions of both surfaces via the CO group of their ester function. A very different behavior is found, if the ILs are deposited above the multilayer desorption temperature (400 K). While for [BMIM][NTf2] and [MBMIM][NTf2] a molecularly adsorbed monolayer film is formed, [IPBMIM][NTf2] undergoes a chemical transformation on the CoO(100) surface. Here, the ester group is cleaved and the cation is chemically linked to the surface by formation of a surface carboxylate. The IL‐derived species in the monolayer desorb at temperatures around 500 to 550 K.
Rational Development of Neutral Aqueous Electrolytes for Zinc–Air Batteries
Authors: Clark Simon , Latz Arnulf , Horstmann Birger
Published: September 2017

Neutral aqueous electrolytes have been shown to extend both the calendar life and cycling stability of secondary zinc–air batteries (ZABs). Despite this promise, there are currently no modeling studies investigating the performance of neutral ZABs. Traditional continuum models are numerically insufficient to simulate the dynamic behavior of these complex systems because of the rapid, orders‐of‐magnitude concentration shifts that occur. In this work, we present a novel framework for modeling the cell‐level performance of pH‐buffered aqueous electrolytes. We apply our model to conduct the first continuum‐scale simulation of secondary ZABs using aqueous ZnCl2–NH4Cl as electrolyte. We first use our model to interpret the results of two recent experimental studies of neutral ZABs, showing that the stability of the pH value is a significant factor in cell performance. We then optimize the composition of the electrolyte and the design of the cell considering factors including pH stability, final discharge product, and overall energy density. Our simulations predict that the effectiveness of the pH buffer is limited by slow mass transport and that chlorine‐containing solids may precipitate in addition to ZnO.
Pulmonary blastoma in a child: Report of a case with cytological findings
Authors: Das Mou , Maity Chaudhuri Priyanka , Bandyopadhyay Anis , Chatterjee Uttara
Published: September 2017

Pulmonary blastoma is an uncommon tumour. It constitutes <0.1% of all resected lung cancers. It is even more rare in children with only a few case reports describing this entity in them. Pulmonary blastoma should not be confused with pleuropulmonary blastoma which is a paediatric lung tumour with different morphology and better outcome. Here we take the opportunity of describing pulmonary blastoma in a 3 years old child along with its cytological findings.
Ruthenium and Osmium Germyl Complexes Derived from the Reactions of MXCl(PPh3)3 (M = Ru, Os; X = Cl, H) with Terphenylchlorogermylene (C6H3‐2,6‐Trip2)GeCl (Trip = 2,4,6‐iPr3C6H2)
Authors: Nie Peng , Yu Qian , Zhu Hongping , Wen Ting‐Bin
Published: September 2017

The reactions of MXCl(PPh3)3 (M = Ru, Os; X = Cl, H) with (C6H3‐2,6‐Trip2)GeCl (Trip = 2,4,6‐iPr3C6H2) have been investigated. Teatment of MXCl(PPh3)3 with (C6H3‐2,6‐Trip2)GeCl led to the formation of dichlorogermyl chloro or hydrido ruthenium/osmium complexes (PPh3)XMGeCl2(C6H3‐2‐{η6‐Trip}‐6‐Trip) (M = Ru, X = Cl, 1; M = Os, X = Cl, 2; M = Ru, X = H, 3; M = Os, X = H, 4) through insertion of the germylene into the M–Cl bond followed by η6‐coordination of one of the Trip groups of the terphenyl to the Ru/Os center with concomitant dissociation of PPh3 ligands. Noteworthily, the reaction on OsHCl(PPh3)3 also led to the formation of an unexpected minor product Os(H)(PPh2C6H4)GeCl(C6H3‐2‐{η6‐Trip}‐6‐Trip) (5) containing a diphenylphosphinophenyl‐germyl ligand, which is presumably formed by orthometalation of the PPh3 ligand through dehydrochorination in the germylidene intermediate followed by migration of the metalated phenyl group to germanium. Reaction of 1 with PMe3 or treatment of 1 with DMSO in the presence of CuCl as the phosphine scavenger produced the PMe3‐ or DMSO‐substituted derivatives (L)ClRuGeCl2(C6H3‐2‐{η6‐Trip}‐6‐Trip) (L = PMe3, 6; L = DMSO, 7). The reaction of 1 with LiHBEt3 afforded hydrido ruthenium complex 3, while treatment of 3 with PhCH2MgCl led to benzylation at Ge to give hydrido ruthenium–dibenzylgermyl complex (PPh3)(H)RuGe(CH2Ph)2(C6H3‐2‐{η6‐Trip}‐6‐Trip) (8).
An Efficient Synthetic Approach to Calix[n]furan[4‐n]pyrroles and the Calix[n]tetrahydrofuran[4‐n]pyrrolidines
Authors: Maupillier William , Journot Guillaume , Stoeckli‐Evans Helen , Neier Reinhard
Published: September 2017

A scalable synthesis of calix[n]furan[4‐n]pyrroles and their fully reduced analogues, calix[n]tetrahydrofuran[4‐n]pyrrolidines obtained by hydrogenation of their aromatic relatives, was developed and optimized. The hydrogenation reaction was studied at several selected pressures (P = 100, 50 and 15 bars) and high diastereoselectivity was observed for the four possible calix[n]tetrahydrofuran[4‐n]pyrrolidines. Moreover, two of the saturated macrocycles were obtained with good overall yields starting from easily accessible calix[4]furan. The conformation of the eight macrocycles was analyzed by X‐ray diffraction and although a classical 1,3‐alternate conformation of this type of compound was observed for the aromatic macrocycles, two distinct types of conformation were observed with the calix[n]tetrahydrofuran[4‐n]pyrrolidines.
Silver‐Catalyzed Decarboxylative Radical Addition/Cyclization of α,α‐Difluoroarylacetic Acids with Acrylamides To Synthesize Difluorinated Oxindoles
Authors: Li Yin‐Long , Wang Ji‐Bo , Wang Xue‐Lin , Cao Yang , Deng Jun
Published: September 2017

A facile silver‐catalyzed decarboxylative radical addition/cyclization reaction of α,α‐difluoroarylacetic acids and acrylamides has been disclosed. The method provides a highly attractive approach to synthesize a series of difluorinated oxindoles that contain various functional groups in moderate to good yields under mild conditions. Moreover, experimental studies reveal that the CF2 group of the α,α‐difluoroarylacetic acids plays a vital role in the transformation.
Regulation of fibroblast growth factor 8 (FGF8) in chicken embryonic stem cells differentiation into spermatogonial stem cells
Authors: Wang Man , Zhang Chen , Huang Chuanli , Cheng Shaoze , He Nana , Wang Yilin , Ahmed Mahmoud F. , Zhao Ruifeng , Jin Jing , Zuo Qisheng , Zhang Yani , Li Bichun
Published: September 2017

Fibroblast growth factors (FGFs) are essential in regulating the formation of spermatogonial stem cells (SSCs). Here, we explored the effect of FGF8 on chicken SSCs formation by knockdown or overexpression of FGF8 in chicken embryonic stem cells (ESCs) both in vitro and in vivo. Our results showed that knockdown of FGF8 could facilitate the differentiation of ESCs into SSCs, overexpression of FGF8 could promote PGCs self‐renewal, inhibit SSCs formation. This study further revealed the positive correlation between the expression level of FGF8 and MAPK/ERK signal. In the absence of FGF8, the expression of downstream genes such as FGFR2, GRB2, RAS, BRAF, RAF1, and MEK2 was not maintained, while overexpressing FGF8 enhances them. Thus, our study demonstrated that FGF8 can regulate germ cell fate by modulating the dynamic equilibrium between differentiation and self‐renewal, which provides a new idea for the study of germ cell regulatory network.
Enhanced heterologous expression of Trichoderma reesei Cel5A/Cel6A in Pichia pastoris with extracellular co‐expression of Vitreoscilla hemoglobin
Authors: Sun Fubao Fuelbiol , Yang Huimin , Bai Renhui , Fang Xu , Wang Fei , He Jing , Tu Maobing
Published: September 2017

BACKGROUND

The deficiency of family 5 endoglucanase (Cel5A) and family 6 cellobiohydrolase (Cel6A) has become a key limiting factor on cellulase enzymatic hydrolysis in bioprocessing of cellulosic biomass. To improve the production of Trichoderma reesei Cel5A / Cel6A, a Vitreoscilla hemoglobin (VHb) gene was tried to co‐express extracellularly for the first time with Cel5A / Cel6A in Pichia pastoris GS115.

RESULTS

Newly constructed recombinant of co‐expressing Cel5A / Cel6A extracellularly with VHb was consistent with the single expression at some key variables of culture condition, i.e. inoculum size, initial pH, culture temperature and methanol concentration. Comparing their single expression, the CMCase activity of co‐expressed Cel5A and Cel6A enzymes enhanced by 40% and 30%, respectively. With high‐cell‐density fed‐batch (HCDFB) fermentation, the co‐expressed Cel5A enzyme activity was 366.8 U mL‐1 with 4.3 g L‐1 protein content and the Cel6A enzyme activity reached 1.3 U mL‐1 with 2.23 g L‐1 protein content. The two co‐expressed enzyme activities were enhanced by 35% and 20%, respectively, compared with the single expression.

CONCLUSION

VHb protein capable of binding oxygen can be successfully co‐expressed extracellularly with other target proteins. The co‐expression of VHb with recombinant Cel5A / Cel6A is efficient at improving oxygen‐limited condition and thus enzyme production in both shake‐flask and HCDFB fermentation. © 2017 Society of Chemical Industry
An Euler‐genus approach to the calculation of the crosscap‐number polynomial
Authors: Chen Yichao , Gross Jonathan L.
Published: September 2017

In 1994, J. Chen, J. Gross, and R. Rieper demonstrated how to use the rank of Mohar's overlap matrix to calculate the crosscap‐number distribution, that is, the distribution of the embeddings of a graph in the nonorientable surfaces. That has ever since been by far the most frequent way that these distributions have been calculated. This article introduces a way to calculate the Euler‐genus polynomial of a graph, which combines the orientable and the nonorientable embeddings, without using the overlap matrix. The crosscap‐number polynomial for the nonorientable embeddings is then easily calculated from the Euler‐genus polynomial and the genus polynomial.
The Effect of Child's School Entry on Maternal Employment: Regression Discontinuity Evidence from South Korea
Authors: Choi Jaehee , Jung Haeil
Published: September 2017

Public school is a form of highly subsidized, universal childcare and thus an important aspect of childcare policies. We examine the impact of a child's school entry on maternal employment in South Korea where mothers have been inactive in the labour force. We utilize a natural experiment where the school‐age eligibility requirement in South Korea generates an exogenous variation in the cost of childcare and lends itself to a regression discontinuity design. Our findings suggest that for women with low levels of own or spouse's education, enrolling their children in school leads to a sizeable increase in labour force participation. Copyright © 2017 John Wiley & Sons, Ltd.
Protein surface roughness accounts for binding free energy of Plasmepsin II‐ligand complexes
Authors: Valdés‐Tresanco Mario E. , Valdés‐Tresanco Mario S. , Valiente Pedro A. , Cocho Germinal , Mansilla Ricardo , Nieto‐Villar J.M.
Published: September 2017

The calculation of absolute binding affinities for protein‐inhibitor complexes remains as one of the main challenges in computational structure‐based ligand design. The present work explored the calculations of surface fractal dimension (as a measure of surface roughness) and the relationship with experimental binding free energies of Plasmepsin II complexes. Plasmepsin II is an attractive target for novel therapeutic compounds to treat malaria. However, the structural flexibility of this enzyme is a drawback when searching for specific inhibitors. Concerning that, we performed separate explicitly solvated molecular dynamics simulations using the available high‐resolution crystal structures of different Plasmepsin II complexes. Molecular dynamics simulations allowed a better approximation to systems dynamics and, therefore, a more reliable estimation of surface roughness. This constitutes a novel approximation in order to obtain more realistic values of fractal dimension, because previous works considered only x‐ray structures. Binding site fractal dimension was calculated considering the ensemble of structures generated at different simulation times. A linear relationship between binding site fractal dimension and experimental binding free energies of the complexes was observed within 20 ns. Previous studies of the subject did not uncover this relationship. Regression model, coined FD model, was built to estimate binding free energies from binding site fractal dimension values. Leave‐one‐out cross‐validation showed that our model reproduced accurately the absolute binding free energies for our training set (R2 = 0.76;
 =0.55 kcal/mol; SDerror = 0.19 kcal/mol). The fact that such a simple model may be applied raises some questions that are addressed in the article.
Testate amoeba as palaeohydrological indicators in the permafrost peatlands of north‐east European Russia and Finnish Lapland
Authors: Zhang Hui , Amesbury Matthew J. , Ronkainen Tiina , Charman Dan J. , Gallego‐Sala Angela V. , VÄliranta Minna
Published: September 2017

To explore the use of testate amoeba for investigating the impacts of climate change on permafrost peatland hydrology, we established a new modern training set from Arctic permafrost peatlands in north‐east European Russia and Finnish Lapland. Ordination analyses showed that water‐table depth (WTD) was the most important control on testate amoeba distribution. We developed a new testate amoeba‐based WTD transfer function and thoroughly tested it. We found that our transfer function had strong predictive power. The best‐performing model was based on tolerance‐downweighted weighted averaging with inverse deshrinking (R2 = 0.77, RMSEP = 5.62 cm with leave‐one‐out cross validation). The new transfer function was applied to a short peat core from Arctic Russia and revealed two major hydrological shifts, which could be validated against plant macrofossil data. We also compared our model to another two models from more temperate peatlands. Comparison of the different testate amoeba datasets suggests that testate amoeba ecohydrological relationships are similar for permafrost peatlands to those in more temperate regions, but there are some differences that suggest a need for training datasets that are fully representative of permafrost peatlands.
Cover Image, Volume 97, Issue 13
Authors: Carvalho Márcia , Lino‐Neto Teresa , Rosa Eduardo , Carnide Valdemar
Published: September 2017

The cover image, by Márcia Carvalho et al., is based on the Review Cowpea: a legume crop for a challenging environment, DOI: 10.1002/jsfa.8250. Photo Credit: Eduardo Rosa.

image
Dynamic gastric digestion of a commercial whey protein concentrate†
Authors: Miralles Beatriz , del Barrio Roberto , Cueva Carolina , Recio Isidra , Amigo Lourdes
Published: September 2017

BACKGROUND

A dynamic gastrointestinal simulator, simgi®, has been applied to assess the gastric digestion of a whey protein concentrate. Samples collected from the outlet of the stomach have been compared to those resulting from the static digestion protocol INFOGEST developed on the basis of physiologically inferred conditions.

RESULTS

Progress of digestion was followed by SDS‐PAGE and LC–MS/MS. By SDS‐PAGE, serum albumin and α‐lactalbumin were no longer detectable at 30 and 60 min, respectively. On the contrary, β‐lactoglobulin was visible up to 120 min, although in decreasing concentrations in the dynamic model due to the gastric emptying and the addition of gastric fluids. Moreover, β‐lactoglobulin was partly hydrolysed by pepsin probably due to the presence of heat‐denatured forms and the peptides released using both digestion models were similar. Under dynamic conditions, a stepwise increase in number of peptides over time was observed, while the static protocol generated a high number of peptides from the beginning of digestion.

CONCLUSION

Whey protein digestion products using a dynamic stomach are consistent with those generated with the static protocol but the kinetic behaviour of the peptide profile emphasises the effect of the sequential pepsin addition, peristaltic shaking, and gastric emptying on protein digestibility. © 2017 Society of Chemical Industry
Business and government interdependence in emerging economies: Insights from hotels in Ghana
Authors: Amankwah‐Amoah Joseph , Debrah Yaw A. , Honyenuga Ben Q. , Adzoyi Paulina N.
Published: September 2017

Although social science research is replete with scholarly works on capacity building, relatively few studies have focused on how government can induce capacity building among privately owned enterprises in emerging economies. We seek to fill the lacuna in our understanding by examining how a government can induce capacity building among privately owned enterprises. The study adopted a qualitative approach using semi‐structured interviews with hotel owners, employees, and managers, as well as government officials in Ghana to examine the issue. We identified three unique stages through which such capacity‐building initiatives unfold encompassing diagnosing, renewal, and customer centricity. The study revealed that capacity building through collaborative partnership was partly motivated by desire to overcome societal resistance to services seen as “tainted.” The concluding section outlines a number of theoretical and practical implications.
Effects of short‐term variations in sea level on dissolved oxygen in a coastal karst aquifer, Quintana Roo, Mexico
Authors: Young Caitlin , Martin Jonathan B. , Branyon Jackie , Pain Andrea , Valle‐Levinson Arnoldo , Mariño‐Tapia Ismael , Vieyra Mario Rebolledo
Published: September 2017

Sea‐level rise should cause salt‐water intrusion into coastal aquifers and limit fresh submarine groundwater discharge. Pargos Spring offshore of Puerto Morelos, Quintana Roo, Mexico, intermittently discharges brackish water and allows intrusion of lagoon water with seawater salinity to the aquifer. Lagoon water intrusion occurred when sea level was > 0.08 m above mean observed values during the study period. Salt water intrusion will be permanent within a few decades at the current eustatic sea‐level rise rate of ∼ 3 mm/yr. A mixing model demonstrates that oxygen dissolved in the lagoon water is reduced as it intrudes the spring. Dissolved oxygen (DO) reduction is greater at the spring vent than at sensors ∼ 10 m inside the conduit, reflecting rapid reaction kinetics. DO reduction results from organic carbon remineralization, which also releases N and P to the water. Increased frequency of intrusion events or continuous intrusion may alter microbially mediated biogeochemical reactions, thereby increasing aquifer vulnerability to sea‐level rise.
Chirality Driven by Magnetic Dipole Response for Demultiplexing of Surface Waves
Authors: Sinev Ivan S. , Bogdanov Andrey A. , Komissarenko Filipp E. , Frizyuk Kristina S. , Petrov Mihail I. , Mukhin Ivan S. , Makarov Sergey V. , Samusev Anton K. , Lavrinenko Andrei V. , Iorsh Ivan V.
Published: September 2017

Surface electromagnetic waves are characterized by the intrinsic spin‐orbit interaction which results in the fascinating spin‐momentum locking. Therefore, directional coupling of light to surface waves can be achieved through chiral nanoantennas. Here, we show that dielectric nanoantenna provides chiral response with strong spectral dependence due to the interference of electric and magnetic dipole momenta when placed in the vicinity of the metal‐air interface. Remarkably, chiral behaviour in the proposed scheme does not require elliptical polarization of the pump beam or the geometric chirality of the nanoantenna. We show that the proposed ultracompact and simple dielectric nanoantenna allows for both directional launching of surface plasmon polaritons on a thin gold film and their demultiplexing with a high spectral resolution.
The impact of death on consumer responses to celebrity endorser misbehavior
Authors: Boeuf Benjamin
Published: September 2017

A well‐established stream of research on celebrity misbehavior suggests that negative information may have an adverse effect on an endorsed brand because of its association with a celebrity considered as blameworthy. However, the present research calls into question the generalizability of these results to fatal misbehaviors (i.e., misbehaviors that lead to the celebrity's death). Indeed, after death, a celebrity may gain spiritual meanings, and consumers may find it more difficult to blame a sacred individual. As such, the current article investigates the impact of a celebrity's death on blame attribution and consumer attitudes in the context of celebrity endorser misbehavior. The results of three experiments uncover that death favors a partial blame attribution transfer from the celebrity endorser to the brand, but only when the misbehavior implies a product related to the brand. In addition, the findings reveal a positive effect of death through celebrity sacredness on brand attitude.
Long‐Lived Supramolecular Helices Promoted by Fluorinated Photoswitches
Authors: Huang He , Orlova Tetiana , Matt Benjamin , Katsonis Nathalie
Published: September 2017

Chiral azobenzenes can be used as photoswitchable dopants to control supramolecular helices in liquid crystals. However, the lack of thermal stability of the cis‐isomer precludes envisioning the generation of long‐lived supramolecular helices with light. Here, this study demonstrates thermally stable and axially chiral azobenzene switches that can be used as chiral dopants to create supramolecular helices from (achiral) nematic liquid crystals. Their trans‐to‐cis photoisomerization leads to a variation of helical twisting power that reaches up to 60%, and the helical superstructure that is engineered with light displays a relaxation time that reaches tens of hours. These results demonstrate that combining ortho‐fluorination with axial chirality in molecular photoswitches constitutes an efficient strategy to promote long‐lived helical states. Further, this approach shows potential to design supramolecular machines that are controlled by light entirely.
Nano‐Star‐Shaped Polymers for Drug Delivery Applications
Authors: Yang Da‐Peng , Oo Ma Nwe Nwe Linn , Deen Gulam Roshan , Li Zibiao , Loh Xian Jun
Published: September 2017

With the advancement of polymer engineering, complex star‐shaped polymer architectures can be synthesized with ease, bringing about a host of unique properties and applications. The polymer arms can be functionalized with different chemical groups to fine‐tune the response behavior or be endowed with targeting ligands or stimuli responsive moieties to control its physicochemical behavior and self‐organization in solution. Rheological properties of these solutions can be modulated, which also facilitates the control of the diffusion of the drug from these star‐based nanocarriers. However, these star‐shaped polymers designed for drug delivery are still in a very early stage of development. Due to the sheer diversity of macromolecules that can take on the star architectures and the various combinations of functional groups that can be cross‐linked together, there remain many structure–property relationships which have yet to be fully established. This review aims to provide an introductory perspective on the basic synthetic methods of star‐shaped polymers, the properties which can be controlled by the unique architecture, and also recent advances in drug delivery applications related to these star candidates.
Taming Macromolecules with Light: Lessons Learned from Vibrational Spectroscopy
Authors: Vapaavuori Jaana , Bazuin C. Geraldine , Pellerin Christian
Published: September 2017

Exciting new applications, from large‐area nanopatterning and templating to soft light‐powered robotics, are emerging from the fundamental research on light‐triggered changes in macromolecular systems upon photoisomerization of azobenzene‐based molecular photoswitches. The understanding of how the initial molecular‐scale photoisomerization of azobenzene, a complex photochemical event in itself, is translated into the response of macromolecules and even into macroscopic‐scale motion of illuminated azomaterials is an enormous task. The focus here is on how this knowledge has advanced by applying different vibrational spectroscopy techniques that provide rich molecular insight into the photoresponse of chemically specific molecular moieties. In particular, infrared and Raman spectroscopy studies are highlighted, in the context of phototriggered perturbation of self‐assembled structures and photoinduced linear and circular anisotropy, as well as photoinduced surface patterning, with the objective of offering a perspective on how vibrational spectroscopy can help in answering an array of essential yet unsettled questions.
CO2‐Induced Morphological Transition of Co‐Assemblies from Block‐Random Segmented Polymers
Authors: Yin Hongyao , Wang Wei , Mu Meng , Feng Yujun
Published: September 2017

The co‐assembly process is an effective approach to construct hierarchically nanostructured soft materials, but morphological transition of co‐assemblies upon external stimuli, particularly the “green” trigger CO2, is not unraveled yet. Here, a segmented copolymer, poly(styrene)‐block‐poly[(4‐vinyl pyridine)–random‐((2‐(diethylamino)ethyl methacrylate)] (P1), is used to co‐assemble in the mixed solvent of dimethyl formamide and water with poly(ethylene oxide)‐block‐poly[(4‐vinyl pyridine)–random‐((2‐(diethylamino)ethyl methacrylate)] (P2) and poly(ethylene oxide)‐block‐poly(acrylic acid) (P3), respectively. It is found that Janus micelles are generated from the P1–P2 pair in the presence of ferric ion, while wormlike micelles are formed from the P1–P3 duad. Upon stimulation with CO2, Janus and wormlike aggregates are transferred into core–shell and spherical micelles, respectively.
Estimation of DIEP flap weight for breast reconstruction by the pinch test
Authors: Woo Kyong‐Je , Mun Goo‐Hyun
Published: September 2017

Background

Various methods have been introduced for estimating deep inferior epigastric artery perforator (DIEP) flap volume based on computed tomography or magnetic resonance angiographic images. However, when radiologic images cannot be obtained, estimations are subjective. The purpose of this study was to develop a prediction model for estimating DIEP flap weight using the pinch test.

Methods

The pinch test was performed at three paraumbilical sites using a skin‐fold caliper in 107 consecutive patients who underwent DIEP flap breast reconstruction. Multiple linear regression analysis was used to develop a formula to estimate flap weight. Predictor variables included body mass index (BMI, kg/m2), flap height (H, cm), flap width (W, cm), and flap thickness (mm) measured by the pinch test at the following three paraumbilical sites: 5 cm right (R), left (L), and inferior (I) of the umbilicus. The model accuracy was tested using leave‐one‐out cross‐validation.

Results

A prediction model was developed from the multiple regression analysis (R2 = 89.03%, P < .001); flap weight, g = −1308 + 24.57 × BMI + 6.80 × (R + L)/2 + 7.89 × I + 20.51 × H + 32.55 × W. The formula was implemented in a smartphone application, DIEP‐W version 2.0, for real‐time use. The mean absolute percentage error in the cross‐validation was 12.15%.

Conclusions

DIEP flap weight can be estimated by the pinch test with the developed prediction model in an easy, cost‐effective, and relatively accurate manner. This method will improve surgical planning and allow surgeons to provide better counselling for patients when radiologic images are not available.
Simultaneous double free radial forearm flaps combined with coronoidectomy and myotomy to release bilateral severe trismus: A case report
Authors: Chou Chieh , Chen Chien‐Chang , Lai Chung‐Sheng , Lin Sin‐Daw , Kuo Yur‐Ren
Published: September 2017

Oral cancers associated with submucosal fibrosis‐induced trismus are common. They may affect the patients' quality of life, cause nutritional deficits, and interfere with postoperative cancer surveillance. In such cases, locating desirable recipient vessels in the head and neck can be difficult. This report presents a 47‐year‐old man with severe trismus caused by recurrent head and neck cancer, who had received multiple free‐flap reconstructions after cancer ablation. Reconstruction was successfully achieved for the bilateral defects and releasing the trismus by using simultaneous double free radial forearm flaps as a chained flow‐through pattern with one residual recipient vessel combined with the bilateral myotomy of the medial pterygoid and masseter muscles, and coronoidectomy. Both flaps survived without any postoperative complication. The maximal mouth opening measured by interincisal distance was 38 mm intraoperative and 32 mm during the 3‐year follow‐up period. This approach may be an effective option for releasing trismus when recipient vessels are lacking.
The Varying Role of Vertebrae in Pacific Fishbone Analysis: Comparing Tropical Versus Temperate Midden Assemblages
Authors: Harris T. E. , Lilley K. A. , Walter R. K.
Published: September 2017

Archaeologists working in the tropical Pacific have demonstrated the feasibility and value of including fish vertebrae in midden analyses, and recent New Zealand studies draw similar conclusions. This work provides an illustrated guide to the identification of vertebrae from key New Zealand fish taxa and shows the effects of including vertebrae on a large fishbone assemblage from southern New Zealand. We note major differences between New Zealand and tropical Pacific assemblages resulting from the inclusion of vertebrae. Unlike the Indo‐Pacific taxa of the tropical Pacific, no New Zealand species have been shown to be sensitive to the inclusion of vertebrae. In both places, including vertebrae results in changes in relative abundance and rank order; but in New Zealand, this is a function of processing practices, not fishing behaviours. This work serves to highlight changes in the Polynesian fishing adaption following the colonisation of New Zealand. Copyright © 2017 John Wiley & Sons, Ltd.