bluuebunny/crossref_metadata_2025 huggingface dataset:
Terminal Hydride Species in [FeFe]‐Hydrogenases Are Vibrationally Coupled to the Active Site Environment
Authors: Pham Cindy C. , Mulder David W. , Pelmenschikov Vladimir , King Paul W. , Ratzloff Michael W. , Wang Hongxin , Mishra Nakul , Alp Esen E. , Zhao Jiyong , Hu Michael Y. , Tamasaku Kenji , Yoda Yoshitaka , Cramer Stephen P.
Published: June 2018

A combination of nuclear resonance vibrational spectroscopy (NRVS), FTIR spectroscopy, and DFT calculations was used to observe and characterize Fe−H/D bending modes in CrHydA1 [FeFe]‐hydrogenase Cys‐to‐Ser variant C169S. Mutagenesis of cysteine to serine at position 169 changes the functional group adjacent to the H‐cluster from a ‐SH to ‐OH, thus altering the proton transfer pathway. The catalytic activity of C169S is significantly reduced compared to that of native CrHydA1, presumably owing to less efficient proton transfer to the H‐cluster. This mutation enabled effective capture of a hydride/deuteride intermediate and facilitated direct detection of the Fe−H/D normal modes. We observed a significant shift to higher frequency in an Fe−H bending mode of the C169S variant, as compared to previous findings with reconstituted native and oxadithiolate (ODT)‐substituted CrHydA1. On the basis of DFT calculations, we propose that this shift is caused by the stronger interaction of the ‐OH group of C169S with the bridgehead ‐NH‐ moiety of the active site, as compared to that of the ‐SH group of C169 in the native enzyme.
Engineering a Cu‐MOF Nano‐Catalyst by using Post‐Synthetic Modification for the Preparation of 5‐Substituted 1H‐Tetrazoles
Authors: Salahshournia Behrang , Hamadi Hosein , Nobakht Valiollah
Published: June 2018

A new nano scale Cu‐MOF has been obtained via post‐synthetic metalation by immersing a Zn‐MOF as a template in DMF solutions of copper(II) salts. The Cu‐MOF serves as recyclable nano‐catalyst for the preparation of 5‐substituted 1H‐tetrazoles via [3 + 2] cycloaddition reaction of various nitriles and sodium azide in a green medium (PEG). The post‐synthetic metalated MOF were characterized by FT‐IR spectroscopy, powder X‐ray diffraction (PXRD), atomic absorption spectroscopy (AAS), and energy dispersive X‐ray spectroscopy (EDX) techniques. The morphology and size of the nano‐catalyst were determined by field emission scanning electron microscopy (FE‐SEM).
Urea‐based amphiphilic porous organic polymer‐supported palladium as a reusable catalyst for Suzuki–Miyaura coupling and hydroxycarbonylation reactions in water
Authors: Lei Yizhu , Lan Guosong , Zhu Dajian , Wang Renshu , Zhou Xiao‐Yu , Li Guangxing
Published: June 2018

The development of environmentally friendly heterogeneous catalysts for organic reactions in water is becoming of growing importance for the development of sustainable processes. In this work, a porous organic polymer‐supported palladium catalyst (Pd@UPOP‐1) was successfully fabricated from 3,3′‐diaminobenzidine and methylenediphenyl diisocyanate through a facile urea‐forming condensation reaction. The structure and composition of the catalyst were characterized using several physicochemical methods. Pd@UPOP‐1 was found to possess good porous structure and excellent amphiphilicity. Under mild reaction conditions, the catalyst showed excellent catalytic activity and good substrate compatibility for the Suzuki–Miyaura coupling reaction of aryl bromides, as well as the hydroxycarbonylation reaction of aryl iodides. In addition, the catalyst could be used for several consecutive recycles in both cases.
Topoisomerase I inhibitory and photocleavage activity of non‐dppz DNA ‘light switches’ based on ruthenium complexes containing nitro group
Authors: Liu XueWen , Huang Jie , Tang YuXuan , Shen YouMing , Lu JiLin
Published: June 2018

A new polypyridyl ligand containing a nitro group and two new ruthenium complexes of it were synthesized. The two complexes exhibited non‐dppz DNA ‘light switch’ effects after interaction with calf thymus DNA. Introducing both electron‐withdrawing group (─ NO2) and electron‐donating group (─ CH3) may be the reason that the two complexes display DNA ‘light switch’ behaviors. Furthermore, one of the complexes showed higher photocleavage activity, topoisomerase I inhibition activity and DNA affinity than the other. The present work shows that the more active complex can be employed as a non‐dppz DNA ‘light switch’, DNA photocleaver and topoisomerase I inhibitor. In addition, the two complexes have no or weak cytotoxic activities against Eca‐109 and A549 cells.
Selective vapor‐phase oxidation of o‐xylene to phthalic anhydride over Co‐Mn/H3PW12O40@TiO2 using molecular oxygen as a green oxidant
Authors: Masoomi Kianoosh , Ghiaci Mehran , Botelho do Rego A.M.
Published: June 2018

The oxidation of o‐xylene to phthalic anhydride over Co‐Mn/H3PW12O40@TiO2 was investigated. The experimental results demonstrated that the prepared catalyst effectively catalyzed the oxidation of o‐xylene to phthalic anhydride. Also, the synergistic effect between three metals plays vital roles in this reaction. From a green chemistry point of view, this method is environmentally friendly due to carrying out the oxidation in a fixed‐bed reactor under solvent‐free condition and using molecular oxygen as a green and cheap oxidizing agent. The resulting solid catalysts were characterized by FT‐IR, XRD, XPS, ICP‐OES, FESEM, TEM, EDX, DR‐UV spectroscopy, BET and thermogravimetric analysis. The oxidation of o‐xylene yields four products: o‐tolualdehyde, phthaldialdehyde, phthalide and finally phthalic anhydride as the main product. The reaction conditions for oxidation of o‐xylene were optimized by varying the temperature, weight hourly space velocity and oxygen flow rate (contact time). The optimum weight percentage of phosphotungstic acid (HPW) and Co/Mn for phthalic anhydride production were 15 wt % and 2 wt%, respectively. The best Co/Mn ratio was found to be 10/1. Oxygen flow rate was very important on the phthalic anhydride formation. The optimum conditions for oxidation of o‐xylene were T = 370 °C, WHSV = 0.5 h−1 and oxygen flow rate = 10 mL min−1. Under optimized conditions, a maximum of 88.2% conversion and 75.5% selectivity to phthalic anhydride was achieved with the fresh catalyst. Moreover, reusability of the catalyst was studied and catalytic activity remained unchanged after at least five cycles.
A Glass Darkly
Authors: San Roque Craig
Published: June 2018

This paper is based upon the images and thinking of two central Australian men, Andrew Spencer Japaljarri and Rod Moss, both embedded in the arduous and localized circumstances of pragmatic intercultural recognition. Their paintings are philosophical meditations on the state of relations in this part of the country. The author emphasizes that authentic constitutional recognition depends upon authentic interpersonal relationships. This is hard to achieve and hard to sustain.
Hyperporous‐Carbon‐Supported Nonprecious Metal Electrocatalysts for the Oxygen Reduction Reaction
Authors: Zhai Tian‐Long , Xuan Cuijuan , Xu Jincheng , Ban Li , Cheng Zhiming , Wang Shaolei , Wang Deli , Tan Bien , Zhang Chun
Published: June 2018

Highly porous carbonaceous nonprecious metal catalysts for the oxygen reduction reaction are prepared by carbonization of low‐cost metalloporphyrin‐based hyper‐crosslinked polymers (MPH‐X). With high surface area (2768 m2 g−1), hierarchical porous structure, and high metal loading (9.97 wt %), the obtained hyperporous carbon MPH‐Fe/C catalyst exhibits high oxygen reduction reaction (ORR) activity with a half‐wave potential (0.816 V) that is comparable to the 0.819 V of commercial Pt/C. Stability tests reveal that MPH‐Fe/C also exhibits outstanding long‐term durability and methanol tolerance. Our findings may offer an alternative approach to produce nonprecious metal ORR catalysts on a large scale owing to the low‐cost MPH‐X precursors with diverse metal types.
Decoupling control for wastewater treatment process based on recurrent fuzzy neural network
Authors: Qiao Jun‐Fei , Han Gai‐Tang , Han Hong‐Gui , Yang Cui‐Li , Li Wei
Published: June 2018

Due to the characteristics of strong coupling and high nonlinearity in the control process, an intelligent decoupling control strategy based on recurrent fuzzy neural network (RFNN) is proposed in this paper to control the wastewater treatment process (WWTP). Firstly, the architecture of the RFNN controller is designed with a mechanism analysis of WWTP. Secondly, a decoupling strategy in combination with a gradient descent search algorithm is used to decouple the control loop of dissolved oxygen (DO) concentration and nitrate nitrogen (SNO) concentration. Finally, stability analysis based on a Lyapunov function is investigated. The proposed approach has been applied to the WWTP simulation model. Compared to model predictive control, echo state network‐based HDP (E‐HDP), conventional RFNN, and neural network on‐line modelling and controlling methods, the proposed method has better control performance.
Formation of the Solid Electrolyte Interphase at Constant Potentials: A Model Study on Highly Oriented Pyrolytic Graphite
Authors: Antonopoulos Byron K. , Maglia Filippo , Schmidt‐Stein Felix , Schmidt Jan P. , Hoster Harry E.
Published: June 2018

The solid electrolyte interphase (SEI) on graphite anodes is a key enabler for rechargeable lithium‐ion batteries (LIBs). It ensures that only Li+ ions and no damaging electrolyte components enter the anode and hinders electrolyte decomposition. Its growth should be confined to the initial SEI formation process and stop once the battery is in operation to avoid capacity/power loss. In technical LIB cells, the SEI is formed at constant current, with the potential of the graphite anode slowly drifting from higher to lower voltages. SEI formation rate, composition, and structure depend on the potential and on the chemical properties of the anode surface. Here, we characterize SEIs formed at constant potentials on the chemically inactive basal plane of highly oriented pyrolytic graphite (HOPG). X‐ray photoemission spectroscopy (XPS) detects carbonate species only at lower formation potentials. Cyclic voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS) with Fc/Fc+ as an electrochemical probe demonstrate how the formation potential influences ion transport and electrochemical kinetics to and at the anode surface, respectively. Breaking the EIS data down to a Distribution of Relaxation Times (DRT) reveals distinct kinetics and transport related peaks with varying Arrhenius‐type temperature dependencies. We discuss our findings in the context of previous electrochemical studies and existing SEI models and of SEI formation protocols suitable for industry.
Remotely controlled compressed air spring—Design and implementation for distance education
Authors: Reljić Vule , Milenković Ivana , Bajči Brajan , Šešlija Dragan , Šulc Jovan
Published: June 2018

Developing and using innovative teaching methods might be challenging for designers, teachers, and students. Current work covers the theory, simulation, and remote operation of a mechanical spring. Mechanical spring is presented as a mechatronic device that includes two pneumatic cylinders and accompanying equipment, and supporting software for remote control. This remote experiment enables simulation of different types of springs. The experiment was evaluated by three independent groups: Students, teachers, and independent evaluators. The results point out that developed remote experiment have a positive influence on the learning process.
Survival benefit of sphingosin‐1‐phosphate and receptors expressions in breast cancer patients
Authors: Lei Fu‐Ju , Cheng Bi‐Hua , Liao Pei‐Yin , Wang Hsiao‐Ching , Chang Wei‐Chun , Lai Hsueh‐Chou , Yang Juan‐Cheng , Wu Yang‐Chang , Chu Li‐Ching , Ma Wen‐Lung
Published: June 2018

Sphingosine‐1‐phosphate (S1P) is a bioactive lipid that exerts various pathophysiological functions through binding to its receptor family (S1PRs). Since first report of the breast cancer (BCA) promoting function by S1P production (through the function of sphingosine kinases) and S1P/S1PR signaling, their antagonists have never been successfully progress to clinics after three decades. Taking advantage of bioinformatics linking to gene expression to disease prognosis, we examined the impact of associated genes in BCA patients. We found high gene expressions involved in S1P anabolism suppressed disease progression of patients who are basal cell type BCA or receiving adjuvant therapy. In addition, S1PRs expression also suppressed disease progress of multiple categories of BCA patient progression. This result is contradictory to tumor promoter role of S1P/S1PRs which revealed in the literature. Further examination by directly adding S1P in BCA cells found a cell growth suppression function, which act via the expression of S1PR1. In conclusion, our study is the first evidence claiming a survival benefit function of S1P/S1PR signaling in BCA patients, which might explain the obstacle of relative antagonist apply in clinics.
Identification of differential expressed lncRNAs in human thyroid cancer by a genome‐wide analyses
Authors: Lu Wei , Xu Yongcan , Xu Jiewei , Wang Zhong , Ye Guochao
Published: June 2018

Recently, a growing number of evidence has revealed that long noncoding RNAs (lncRNAs) act as key regulators in various cellular biologic processes, and dysregulation of lncRNAs involves in tumorigenesis and cancer progression. However, the expression pattern, clinical relevance, and biologic function of most lncRNAs in human thyroid cancer remain unclear. To identify more thyroid‐cancer‐associated lncRNAs, we analyzed the expression profile of lncRNAs in thyroid cancer tissues and adjacent normal or non‐tumor tissues using RNA sequencing data and gene microarray data from The Cancer Genome Atlas and Gene Expression Omnibus. Annotation and analyses of these data revealed that hundreds of lncRNAs are differentially expressed in thyroid cancer tissues when compared with normal tissues. By copy number variation analyses, we identified that some of those dysregulated lncRNAs genome locus are accompanied with the copy number amplification or deletion. Moreover, some lncRNAs expression levels are significantly associated with thyroid cancer patients overall or recurrence‐free survival time, such as RUNDC3A‐AS1, FOXD2‐AS1, PAX8‐AS1, and CRYM‐AS1. Furthermore, we validated an lncRNA termed LINC00704 in thyroid cancer cells by performing loss of function assays. Downregulation of LINC00704 could significantly impair thyroid cancer cells proliferation, colony formation, inhibit cell‐cycle progression and cell invasion, and induce cell apoptosis. Taken together, our findings reveal that lots of lncRNAs are dysregulated and may play critical roles in thyroid cancer, and this study could provide useful resource for identification and investigation of novel lncRNA candidates for thyroid cancer.
A case of Extrapulmonary intrathoracic hydatidosis with pseudochylothorax
Authors: Amini Shahideh , Kahramfar Zohreh , Rahimi Besharat
Published: June 2018

Key Clinical Message

Echinococcus is a great re‐emerging public health issue. Intrathoracic and extra pulmonary hydatid cysts with pseudochylothorax are rare. There is no standard treatment in case of hydatidosis with pseudochylothorax. Pharmacotherapy approaches may be an option in case of long duration of disease and high risk for surgery.
Breast metastasis from EGFR‐mutated lung adenocarcinoma: A case report and review of the literature
Authors: Ota Takayo , Hasegawa Yoshikazu , Okimura Akira , Sakashita Katsuya , Sunami Takeshi , Yukimoto Kiyotaka , Sawada Ryugo , Sakamoto Kazutsugu , Fukuoka Masahiro
Published: June 2018

Key Clinical Message

Although lung cancer rarely metastasizes to the breast, we report a case of breast metastasis from lung adenocarcinoma harboring an epidermal growth factor receptor mutation. This breast metastasis was initially considered recurrent breast cancer and was later diagnosed based on histopathological and molecular examinations as metastasis from lung cancer.
Palladium Nanoparticles Supported on Nitrogen‐rich Containing Melamine‐based Microporous Covalent Triazine Polymers as Efficient Heterogeneous Catalyst for C−Se Coupling Reactions
Authors: Sadhasivam Velu , Balasaravanan Rajendiran , Chithiraikumar Chinnadurai , Siva Ayyanar
Published: June 2018

In the present work, microporous nitrogen containing covalent triazine polymers (CTPs) TATAM was synthesized from condensation of 4,4′4′′‐(1,3,5‐triazine‐2,4,6‐triyl) tribenzaldehyde (TATA) and melamine under solvothermal conditions to obtain nitrogen‐ rich triazine containing polymeric supported materials (TATAM). Further, palladium nanoparticles (Pd NPs) were supported on TATAM polymeric networks (Pd@TATAM). The synthesized Pd@TATAM CTPs material was thoroughly characterized by FT‐IR, UV‐DRS, solid state 13C‐CPMAS, XPS, powder X‐ray diffraction, TGA, SEM, TEM. In addition, the characterized Pd@TATAM CTPs were applied to check the catalytic application. The Pd@TATAM was shown to be an efficient and reusable heterogeneous solid catalyst for the formation of C−Se bond through coupling of aryl halide and elemental selenium, dimethyl sulfoxide as a solvent at 100 °C for about 6 h. Besides the absence of metal leaching for catalytic system, it is also observed that the catalyst can be reused for three consecutive cycles with a minimal decrease in its activity.
Template‐free Scalable Synthesis of Flower‐like Co3‐xMnxO4 Spinel Catalysts for Toluene Oxidation
Authors: Wang Yuan , Arandiyan Hamidreza , Liu Yuxi , Liang Yijing , Peng Yue , Bartlett Stuart , Dai Hongxing , Rostamnia Sadegh , Li Junhua
Published: June 2018

The rational design of low‐cost transition metal catalysts that exhibit high activity and selectivity may be the most significantly investigated in heterogeneous catalysis. In this study, Co3‐xMnxO4 (x=0.75, 1.0, and 1.5) mixed metal oxides were successfully synthesized by a controlled template‐free autoclave strategy and studied for toluene oxidation. It is found that the Co‐rich sample showed markedly enhanced activity and the 3D dandelion‐like Co2.25Mn0.75O4 catalyst exhibited in the highest toluene oxidation rate (8.9 μmol/(gcats)) and a 100 % toluene conversion at 239 °C. In situ DRIFTS study indicates that toluene was sequentially oxidized to benzyl radical, benzaldehyde, benzene, oxalic acid, and finally to CO2 and H2O. The interaction between Co and Mn, in conjunction with the high concentration of surface oxygen species and rich surface oxygen vacancies, reasonably explains the elevated catalytic activity and thermal stability for toluene oxidation over 3D flower‐like Co3‐xMnxO4 spinel catalysts.
Tailoring Sensitivity in Electrochemical Nucleic Acid Hybridization Biosensing: Role of Surface Chemistry and Labeling Strategies
Authors: Campuzano Susana , Yáñez‐Sedeño Paloma , Pingarrón José Manuel
Published: June 2018

Electrochemical nucleic acid hybridization biosensors have become a mainstay to detect DNA or RNA targets of interest in clinical diagnostics, environmental monitoring and food quality control. Despite the great progress they demonstrated during the last years, there is a constant demand to improve their performance, mainly in terms of sensitivity, simplicity of protocols and easy implementation in routine and decentralized determinations. Within this context, the tremendous possibilities offered by both, a judicious interfacing of the electrode surface, and the use of innovative labeling strategies not requiring nanomaterials or nucleic acid amplification, is discussed critically in this review.
Mono‐ and Bivalent 14‐3‐3 Inhibitors for Characterizing Supramolecular “Lysine Wrapping” of Oligoethylene Glycol (OEG) Moieties in Proteins
Authors: Yilmaz Elvan , Bier David , Guillory Xavier , Briels Jeroen , Ruiz‐Blanco Yasser B. , Sanchez‐Garcia Elsa , Ottmann Christian , Kaiser Markus
Published: June 2018

Previous studies have indicated the presence of defined interactions between oligo or poly(ethylene glycol) (OEG or PEG) and lysine residues. In these interactions, the OEG or PEG residues “wrap around” the lysine amino group, thereby enabling complexation of the amino group by the ether oxygen residues. The resulting biochemical binding affinity and thus biological relevance of this supramolecular interaction however remains unclear so far. Here, we report that OEG‐containing phosphophenol ether inhibitors of 14‐3‐3 proteins also display such a “lysine‐wrapping” binding mode. For better investigating the biochemical relevance of this binding mode, we made use of the dimeric nature of 14‐3‐3 proteins and designed as well as synthesized a set of bivalent 14‐3‐3 inhibitors for biochemical and X‐ray crystallography‐based structural studies. We found that all synthesized derivatives adapted the “lysine‐wrapping” binding mode in the crystal structures; in solution, a different binding mode is however observed, most probably as the “lysine‐wrapping” binding mode turned out to be a rather weak interaction. Accordingly, our studies demonstrate that structural studies of OEG‐lysine interactions are difficult to interpret and their presence in structural studies may not automatically be correlated with a relevant interaction also in solution but requires further biochemical studies.
Active‐Phase Formation and Stability of Gd/Pt(111) Electrocatalysts for Oxygen Reduction: An In Situ Grazing Incidence X‐Ray Diffraction Study
Authors: Escudero‐Escribano María , Pedersen Anders F. , Ulrikkeholm Elisabeth T. , Jensen Kim D. , Hansen Martin H. , Rossmeisl Jan , Stephens Ifan E. L. , Chorkendorff Ib
Published: June 2018

Alloys of platinum and gadolinium present significant activity enhancement over pure Pt for the oxygen reduction reaction (ORR), both in the form of extended electrode surfaces and nanoparticulate catalysts. The active phase consists of a compressed Pt overlayer formed on Pt5Gd electrodes upon exposure to the electrolyte by acid leaching. Here, we investigate the formation, strain and correlation lengths of the active Pt overlayer by using in situ synchrotron grazing incidence X‐ray diffraction on Gd/Pt(111) single‐crystalline electrodes. The overlayer forms upon exposure to electrolyte under open circuit conditions; the compressive strain relaxes slightly upon repeated electrochemical cycling in the potential range 0.6 to 1.0 V versus the reversible hydrogen electrode (RHE). In addition, the strain relaxes strongly when exposing the electrode to 1.2 V versus RHE, and the thickness of the crystalline portion of the overlayer increases with potential above 1.3 V versus RHE.
Mechanistic Study of Highly Efficient Direct 1,2‐Carboboration of Alkynes with 9‐Borafluorenes
Authors: Shoji Yoshiaki , Shigeno Naoki , Takenouchi Kumiko , Sugimoto Manabu , Fukushima Takanori
Published: June 2018

We recently reported a new one‐pot transformation of alkynes into 9,10‐diarylphenanthrene derivatives, which proceeds through efficient catalyst‐free 1,2‐carboboration of alkynes with 9‐chloro‐9‐borafluorene (1Cl), which yields a chlorodibenzoborepin, followed by oxidative deborylation/C−C coupling of the resultant chlorodibenzoborepin. Herein, based on new experimental observations for the catalyst‐free 1,2‐carboboration by using diphenylacetylenes and 1Br or 1OTf as well as results from theoretical investigations, we show how the substituent on the boron atom of 9‐borafluorene affects the reactivity toward alkynes. Kinetic studies indicated that the 1,2‐carboboration of diphenylacetylene with the borafluorenes can be described as a second‐order reaction. The reaction rates became larger with the increase in the acceptor numbers of the borafluorenes (1Br>1OTf>1Cl), which was evaluated by the Gutmann–Beckett method based on a Lewis acid/base complexation in solution. Interestingly, thermodynamic parameters obtained experimentally indicated that the term of activation entropy, rather than the term of activation enthalpy, largely contributes to the reaction rate. This experimental result was also supported by DFT calculations. Overall, among the borafluorenes examined, 1Br exhibited the highest reactivity toward a wide variety of substituted diarylacetylenes. Similar to the case of chlorodibenzoborepin, when the dibenzoborepin obtained from 1Br or 1OTf was oxidized by using FeCl3, an efficient deborylation/C−C coupling took place to give the corresponding 9,10‐diarylphenanthrene derivatives in high yields.
Gold Nanoparticles Functionalized with RGD‐Semipeptides: A Simple yet Highly Effective Targeting System for αVβ3 Integrins
Authors: Maggi Vito , Bianchini Francesca , Portioli Elisabetta , Peppicelli Silvia , Lulli Matteo , Bani Daniele , Del Sole Roberta , Zanardi Franca , Sartori Andrea , Fiammengo Roberto
Published: June 2018

Effective and selective targeting of the αVβ3 integrin subtype is of high relevance in cancer research for the development of therapeutic systems with improved efficacy and of diagnostic imaging probes. We report here a new class of highly selective, αVβ3‐targeted gold nanoparticles (AuNPs), which carry cyclic 4‐aminoproline‐RGD semipeptides (cAmpRGD) as the targeting moiety immobilized at low surface density on the poly(ethylene glycol) (PEG)‐based nanoparticle coating. We show that these nanoparticles are potent inhibitors of the integrin‐mediated melanoma tumor cell adhesion to vitronectin and are selectively internalized via receptor‐mediated endocytosis. Furthermore, we have developed bifunctional cAmpRGD‐functionalized AuNPs by conjugation of a fluorophore (FAM or TAMRA) to a separate set of reactive groups on the PEG‐based coating. These bifunctional AuNPs not only recapitulate the binding properties of cAmpRGD‐AuNPs but also can be visualized via confocal laser microscopy, allowing direct observation of nanoparticle internalization. The peculiar molecular design of these nanoparticles and their precisely defined architecture at the molecular level accounts for their selective integrin binding with very low nonspecific background.
Synthesis and Catalytic Applications of Multi‐Walled Carbon Nanotube–Polyamidoamine Dendrimer Hybrids
Authors: Desmecht Antonin , Steenhaut Timothy , Pennetreau Florence , Hermans Sophie , Riant Olivier
Published: June 2018

Polyamidoamine (PAMAM) dendrimers were covalently immobilized on multi‐walled carbon nanotubes (MWNT) by two “grafting to” strategies. We demonstrate the existence of non‐covalent interactions between the two components but outline the superiority of our two grafting approaches, namely xanthate and click chemistry. MWNT surfaces were functionalized with activated ester and propargylic moieties prior to their reaction with PAMAM or azido‐PAMAM dendrimers, respectively. The grafting of PAMAM generations 0 to 3 was evaluated with X‐ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), and transmission electron microscopy (TEM). The versatility of our hybrids was demonstrated by post‐functionalization sequences involving copper alkyne–azide cycloaddition (CuAAC). We synthesized homogeneous supported iridium complexes at the extremities of the dendrimers. In addition, our materials were used as templates for the encapsulation of Pd nanoparticles (NPs), validating our nanocomposites for catalytic applications. The palladium‐based catalyst was active for carbonylative coupling over five consecutive runs without loss of activity.
New RuII Scaffold for Photoinduced Ligand Release with Red Light in the Photodynamic Therapy (PDT) Window
Authors: Loftus Lauren M. , Al‐Afyouni Kathlyn F. , Turro Claudia
Published: June 2018

Four new RuII complexes, [Ru(tpy)(L)(CH3CN]+, where tpy=2,2′:6′,2“‐terpyridine and L represents a series of acetylacetonate‐based ligands, were synthesized for enhanced photoinduced ligand release with red light, λirr=655 nm. The metal‐to‐ligand charge transfer, 1MLCT, transitions of these complexes are red‐shifted and exhibit quantum yields of ligand dissociation that are five‐ to seven‐fold greater than that of [Ru(tpy)(bpy)(CH3CN)]2+ (bpy=2,2′‐bipyridine), despite the absence of additional steric distortion. This series of complexes represents a new scaffold for drug photocaging and one of the first examples of RuII photocages that can release nitriles with light in the photodynamic therapy (PDT) window required for optimal tissue penetration.
Catalytic Modification of Dehydroalanine in Peptides and Proteins by Palladium‐Mediated Cross‐Coupling
Authors: de Bruijn A. Dowine , Roelfes Gerard
Published: June 2018

Dehydroalanine (Dha) is a remarkably versatile non‐canonical amino acid often found in antimicrobial peptides. Herein, we present the catalytic modification of Dha by a palladium‐mediated cross‐coupling reaction. By using Pd(EDTA)(OAc)2 as water‐soluble catalyst, a variety of arylboronic acids was coupled to the dehydrated residues in proteins and peptides, such as Nisin. The cross‐coupling reaction gave both the Heck product, in which the sp2‐hybridisation of the α‐carbon is retained, as well as the conjugated addition product. The reaction can be performed under mild aqueous conditions, which makes this method an attractive addition to the palette of bio‐orthogonal catalytic methods.
Elektrochemische und massenspektroskopische Untersuchung von Paracetamol
Authors: Habekost Achim
Published: June 2018

Es werden zwei verschiedene elektrochemische Verfahren (Cyclovoltammetrie und elektrogenerierte Chemilumineszenz ECL) zur qualitativen und quantitativen Analyse des Arzneimittels Paracetamol vorgestellt und mit GC‐MSD Messungen verglichen.
Methinylogation Approach in Chiral Pharmacophore Design: from Alkynyl‐ to Allenyl‐carbinol Warheads against Tumor Cells
Authors: Listunov Dymytrii , Joly Etienne , Duhayon Carine , Saffon‐Merceron Nathalie , Fabing Isabelle , Génisson Yves , Maraval Valérie , Chauvin Remi
Published: June 2018

Extension of a structure–activity relationship study of the antitumor cytotoxicity of lipidic dialkynylcarbinols (DACs) is envisaged by formal methinylogation of one of the ethyndiyl moieties of the DAC warhead into the corresponding allenylalkynylcarbinol (AllAC) counterpart. External AllACs were directly obtained by methinylation of the parent DACs with formaldehyde in either the racemic or scalemic series. Isomers containing external progargyl and propynyl motifs were also prepared. Internal AllACs were obtained as racemic statistical mixtures of stereoisomers in two steps from the key C5‐DAC rac‐TIPS‐C≡C‐CH(OH)‐C≡CH and aldehydes. Kinetic resolution of the (S)‐C5‐DAC in 97 % ee and (R)‐C5‐DAC in 99 % ee was achieved by sequential lipase‐mediated acetylation/hydrolysis using the Candida antartica lipase (Novozyme 435). The four internal AllAC stereoisomers were prepared by asymmetric methinylation with (R)‐ or (S)‐diphenylprolinol as chiral auxiliary. Cytotoxicity assays on HCT116 cancer cells showed that the most active (eutomeric) external or internal AllAC exhibits an S configuration, a fatty chain length of n=12, and a 50 % inhibitory concentration IC50≈1.0 μm.
Tuning the Properties of Periodic Mesoporous Organosilica Films for Low‐k Application by Gemini Surfactants
Authors: Redzheb Murad , Okudur Oguzhan Orkut , Bernstorff Sigrid , Juraic Krunoslav , Van Der Voort Pascal , Armini Silvia
Published: June 2018

Periodic mesoporous organosilica (PMO) thin films were synthesized by evaporation‐induced self‐assembly of 1,2‐bis(triethoxysilyl)ethane and an ionic Gemini 16‐12‐16 surfactant under acidic conditions. The films were characterized by Fourier‐transform infrared spectroscopy, grazing‐incidence small‐angle X‐ray scattering, ellipsometric porosimetry, impedance measurements, and nanoindentation. The ease of control of the packing parameter in Gemini surfactants makes the PMO film templated by a Gemini an exciting first step towards small pore size PMO films with engineered mesostructures.
High Enrichment [13C]‐Labeling of Plants Grown Hydroponically from Seed to Seed in a Controlled 13C‐Carbon Dioxide Atmosphere Enclosure
Authors: Peters Calvin P. , Evans Erin M. , Cohen Jerry D. , Hegeman Adrian D.
Published: June 2018

In vivo isotopic labeling empowers proteomic and metabolomic analyses to resolve relationships between the molecular composition, environment, and phenotype of an organism. Carbon‐13 is particularly useful for plant labeling as it can be introduced via 13CO2 gas and readily assimilated into plant metabolic systems through natural carbon fixation. While short‐term labeling experiments can be performed within a simple sealed enclosure, long‐term growth in an isolated environment raises many challenges beyond nutrient availability and buildup of metabolic waste. Viable growth conditions must be maintained by means that do not compromise the integrity of the carbon‐13 enrichment. To address these issues, an automated growth chamber equipped with countermeasures to neutralize stresses and ensure high isotopic enrichment throughout the life cycle of the plant has been developed. The following describes this growth chamber and its use in an example 130‐day growth of ten soybean plants to full maturity, achieving 100% carbon‐13 enrichment of new seed tissue. © 2018 by John Wiley & Sons, Inc.
Divergence of morphological characters in two white‐eye species (Passeriformes: Zosteropidae) in sympatry
Authors: Wijesundara Chaminda S. , Freed Leonard A.
Published: June 2018

When two ecologically similar, sympatric species compete in their zone of overlap, their traits are expected to diverge in the area of sympatry, while remaining more similar in the areas of allopatry. This reduces competition. In this study, we document divergence of some morphological characters in allopatry and sympatry in two species of white‐eye occurring in Sri Lanka, viz. the Sri Lanka white‐eye (Zosterops ceylonensis) and Oriental white‐eye (Zosterops palpebrosus). The extent of the overlap zone may be as large as 20–30 km in some areas. The study was carried out from February 2013 to July 2015. Birds were captured using mist nets in sympatric and allopatric zones of the two species, and 580 individuals belonging to both species were caught. We found that the bill length, bill width, and mass of the Sri Lanka white‐eye in the zone of overlap were significantly different from those in the allopatric zone. In general, the bill length, bill width, and mass showed an increase in the zone of overlap for the Sri Lanka white‐eye. The sympatric population of the Sri Lanka white‐eye has evolved sufficient differences to be ecologically isolated from the smaller Oriental white‐eye, thereby facilitating coexistence. The larger bill of the Sri Lanka white‐eye in sympatry enables it to be more successful in obtaining food than the other species. The trends of these changes showed that there is gradual replacement of the Oriental white‐eye in the upper elevations.
Diagnostic accuracy of ultrasound and fine‐needle aspiration in the study of thyroid nodule and multinodular goitre
Authors: Rabal Fueyo Antonio , Vilanova Serra Magdalena , Lerma Puertas Enrique , Montserrat Esplugas Enrique , Pérez García José Ignacio , Mato Matute Eugenia , De Leiva Hidalgo Alberto , Moral Duarte Antonio
Published: June 2018

Objective

Ultrasonography and cytology obtained by fine‐needle aspiration are part of the basic study of the thyroid nodule. Although they are not diagnostic in every case, they are cost‐effective methods that inform surgical treatment and its extent. The purpose of this study was to evaluate the accuracy of ultrasonography associated with fine‐needle aspiration to predict malignancy in nodular thyroid pathology.

Design and patients

We collected prospective data from patients undergoing thyroidectomy by single nodule or multinodular goitre between 2006 and 2016. A total of 417 patients were included. Ultrasounds were classified as suspected of malignancy if they had 2 or more of the following characteristics: hypoechogenicity, microcalcifications, intranodular central hypervascularization, irregular margins and poorly defined edges.

Measurements

Ultrasound and fine‐needle aspiration accuracy.

Results

In the postoperative study, 40% presented malignant pathology. 33% of patients with nonsuspicious ultrasound and 73% of those with suspicious ultrasound had malignant disease. Among patients with single nodule and suspicious ultrasound, the malignancy rate reached 80%. As for cytology, 100% of BethesdaVIpatients, 88% of V, 63% ofIV, 31% ofIIIand 12% ofIIwere found to have carcinoma. The combination of the 2 tests showed a high predictive value, particularly in cases of BethesdaIVcytology.

Conclusions

Thyroid cytology provides high predictive value of the presence of carcinoma. The predictive value of ultrasound is also high, mainly in the study of isolated nodules. The combination of the 2 tests results in increased diagnostic accuracy.
Recovery of Functional Ingredients from Antarctic Krill (Euphausia superba) Using an Improved Aqueous Enzymatic Extraction Method with Soybean Oil as Co‐Solvent
Authors: Wang Lingzhao , Shen Yan , Du Yunjian , Qiu Chunjiang , Zhang Junjie , Wang Shujun
Published: June 2018

Antarctic krill are rich sources of functional ingredients, including astaxanthin, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). In this work, the functional ingredients are extracted by an improved aqueous enzymatic extraction method, where exogenous enzymes are not consumed and soybean oil is chosen as co‐solvent. The optimal conditions for oil recovery are determined to be a water addition of 30%, an initial pH of 7.5, a temperature of 43.2 °C, an autolysis time of 6 h, and a soybean oil addition ratio (g/g) of 3. Meanwhile, the oil recovery rate is 76.7%. The recovered oil contains 44.24 mg kg−1 astaxanthin and its total fatty acids contain 1.1% EPA and 0.6% DHA. The moisture and volatile matter content, acid value, and peroxide value of recovered oil are sufficient to meet the first grade requirements of soybean oil. The oxidative stability of recovered oil is close to that of soybean oil at room temperature. The recovered oil can be taken as a good source of EPA, DHA, and astaxanthin for consideration of use as an edible oil item for human consumption.

Practical Applications: Antarctic krill (Euphasia superba) are generally known as huge biomass resources, strong endogenous enzymes, and rich sources of functional ingredients including EPA, DHA, and astaxanthin. In this work, the strong endogenous enzymes are employed to extract the functional ingredients from E. superba using soybean oil as co‐solvent. Furthermore, chemical compositions, physicochemical properties, and oxidative stabilities of the recovered oil are investigated. The results are useful for the extensive utilization of E. superba in food industry.

The functional ingredients including EPA, DHA, and astaxanthin in krill are extracted by an improved aqueous enzymatic extraction method, where exogenous enzymes are not consumed and soybean oil is chosen as co‐solvent. The recovered oil can be taken as a good source of EPA, DHA, and astaxanthin for consideration of use as an edible oil item for human consumption.
A machine‐learned analysis of human gene polymorphisms modulating persisting pain points to major roles of neuroimmune processes
Authors: Kringel D. , Lippmann C. , Parnham M.J. , Kalso E. , Ultsch A. , Lötsch J.
Published: June 2018

Background

Human genetic research has implicated functional variants of more than one hundred genes in the modulation of persisting pain. Artificial intelligence and machine‐learning techniques may combine this knowledge with results of genetic research gathered in any context, which permits the identification of the key biological processes involved in chronic sensitization to pain.

Methods

Based on published evidence, a set of 110 genes carrying variants reported to be associated with modulation of the clinical phenotype of persisting pain in eight different clinical settings was submitted to unsupervised machine‐learning aimed at functional clustering. Subsequently, a mathematically supported subset of genes, comprising those most consistently involved in persisting pain, was analysed by means of computational functional genomics in the Gene Ontology knowledgebase.

Results

Clustering of genes with evidence for a modulation of persisting pain elucidated a functionally heterogeneous set. The situation cleared when the focus was narrowed to a genetic modulation consistently observed throughout several clinical settings. On this basis, two groups of biological processes, the immune system and nitric oxide signalling, emerged as major players in sensitization to persisting pain, which is biologically highly plausible and in agreement with other lines of pain research.

Conclusions

The present computational functional genomics‐based approach provided a computational systems‐biology perspective on chronic sensitization to pain. Human genetic control of persisting pain points to the immune system as a source of potential future targets for drugs directed against persisting pain. Contemporary machine‐learned methods provide innovative approaches to knowledge discovery from previous evidence.

Significance

We show that knowledge discovery in genetic databases and contemporary machine‐learned techniques can identify relevant biological processes involved in Persitent pain.
Reduced Graphene Oxide Nanocomposite Modified Electrodes for Sensitive Detection of Ciprofloxacin
Authors: Pham Tien Song Hiep , Mahon Peter J. , Lai Guosong , Yu Aimin
Published: June 2018

The synthesis of novel nanocomposites with great sensing enhancement has played an important role in analytical chemistry, especially in the electrochemical detection of drug molecules. In this work, we report a wet chemical method for the preparation of a gold nanoparticle coated β‐cyclodextrin functionalized reduced graphene oxide nanocomposite. A number of different analytical techniques including ultraviolet‐visible spectroscopy, fourier transform infrared spectroscopy, scanning electron microscope and energy dispersive X‐ray spectroscopy were employed to characterize the as‐synthesized nanocomposite. With excellent electrocatalytic properties and high supramolecular recognition ability, the as‐synthesized nanocomposite was used to modify a glassy carbon electrode surface for the sensitive determination of ciprofloxacin using voltammetric technique. The current response of ciprofloxacin on the nanocomposite modified electrode was greatly enhanced compared to that on the bare and other modified electrodes. Using differential pulse voltammetry, the oxidation peak currents increased linearly with the ciprofloxacin concentrations in the range between 0.01 to 120 μM with a detection limit of 2.7 nM. The electrochemical testing results showed good stability and reproducibility. Therefore, the nanocomposite could be a potential candidate for the development of electrochemical sensors for sensitive and selective determination of ciprofloxacin or similar drugs in the future.
Iron and zinc levels in Vigna unguiculata (L.) Walp under varying phosphorus and fixed nitrogen treatment conditions
Authors: Ayeni Deborah F. , Ikwebe Joseph , Onyezili Francis N.
Published: June 2018

Using phosphate fertilizer (particularly at high levels) to improve the phosphorus (P) level of soils during the cultivation of legumes and other cereals unfortunately has negative effect on the levels of micronutrients like zinc (Zn) in grains. This study evaluated the influence of P and nitrogen (N) fertilization on iron (Fe) and Zn levels of cowpea grains. Cowpea genotypes B301, TVu 16514, IT90K‐205‐8, UAM09‐1046‐6‐1 and TVu 1272 were grown in greenhouse pots containing barren soils (to simulate micronutrient‐deficient soils) in two stages of varied P (0, 20, 40, and 60 kg P ha−1) with and without N (i.e. P only and P v N). The effect of these interactions on Fe and Zn levels were measured. Application of P alone showed no significant (p > 0.05) negative influence on Zn and Fe content of the grains. However, a combination of N and P fertilization reduced Zn content significantly at 60P (p < 0.05). Further evaluation showed TVu 1272 as highest in terms of Fe and Zn at all P levels. Significant reduction of grain Zn was found at 60P on N and P interaction. No such negative correlation was observed for Fe. TVu 1272 (a high‐yielding genotype) is recommended as a source of high micronutrient.
The optimistic brain: Trait optimism mediates the influence of resting‐state brain activity and connectivity on anxiety in late adolescence
Authors: Wang Song , Zhao Yajun , Cheng Bochao , Wang Xiuli , Yang Xun , Chen Taolin , Suo Xueling , Gong Qiyong
Published: June 2018

As a hot research topic in the field of psychology and psychiatry, trait optimism reflects the tendency to expect positive outcomes in the future. Consistent evidence has demonstrated the role of trait optimism in reducing anxiety among different populations. However, less is known about the neural bases of trait optimism and the underlying mechanisms for how trait optimism protects against anxiety in the healthy brain. In this investigation, we examined these issues in 231 healthy adolescent students by assessing resting‐state brain activity (i.e., fractional amplitude of low‐frequency fluctuations, fALFF) and connectivity (i.e., resting‐state functional connectivity, RSFC). Whole‐brain correlation analyses revealed that higher levels of trait optimism were linked with decreased fALFF in the right orbitofrontal cortex (OFC) and increased RSFC between the right OFC and left supplementary motor cortex (SMC). Mediation analyses further showed that trait optimism mediated the influence of the right OFC activity and the OFC‐SMC connectivity on anxiety. Our results remained significant even after excluding the impact of head motion, positive and negative affect and depression. Taken together, this study reveals that fALFF and RSFC are functional neural markers of trait optimism and provides a brain‐personality‐symptom pathway for protection against anxiety in which fALFF and RSFC affect anxiety through trait optimism.
A pilot longitudinal study of anti‐Müllerian hormone levels throughout gestation in low risk pregnancy
Authors: Freeman Joshua R. , Whitcomb Brian W. , Roy Amrita , Bertone‐Johnson Elizabeth R. , Reich Nicholas G. , Healy Andrew J.
Published: June 2018

Background

Anti‐Mϋllerian hormone (AMH) plays an important role regulating ovarian sensitivity to follicle‐stimulating hormone and luteinizing hormone in folliculogenesis. Anti‐Mϋllerian hormone is well established as a biomarker of ovarian reserve but may also have utility in predicting pregnancy outcomes. Few studies have described AMH levels in pregnancy and, among those that have, most have used cross‐sectional study designs and are limited to participants seeking fertility treatment. Our aim was to analyze AMH longitudinally in low‐risk pregnancies.

Methods

We conducted a prospective cohort study at Baystate Medical Center, a large tertiary care hospital in Springfield, MA, USA. We recruited women (n = 30) with low risk, singleton pregnancies, aged 18 to 35 years, with BMI between 18 and 40 kg/m2, and without preexisting disease. Anti‐Mϋllerian hormone (pmol/L) was measured in plasma samples collected at 5 prenatal care visits throughout gestation.

Results

Anti‐Mϋllerian hormone levels varied significantly over gestation (Friedman's analysis of variance, P value < .0001). At gestational weeks 7 to 10, average AMH was 36.7 pmol/L (standard error = 8.1) and at weeks 34 to 37 was 9.5 pmol/L (standard error = 1.9). Initial AMH varied between women, and an overall significant log‐linear decline was observed.

Conclusions

Anti‐Mϋllerian hormone varies between women and declines exponentially during pregnancy. The biological mechanism of the heterogeneity of AMH decline over gestation is unclear. Future studies evaluating AMH throughout pregnancy that also assess gravid health and pregnancy outcomes are warranted.