bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impact of tetramerization on the ligand recognition of N1 influenza neuraminidase via MMGBSA approach
Authors: Bello Martiniano 
Published: December 2018

AbstractInfluenza virus neuraminidase (NA) is a homotetrameric surface protein that, in contrast to other non‐influenza NAs, requires a quaternary assembly to exhibit enzymatic activity, suggesting that the oligomeric state significantly impacts the active site of influenza NA. Nevertheless, most structure‐based drug design studies have been reported by employing the monomeric state in the closed or open‐loop due to the computational cost of employing the tetrameric NA. In this work, we present MD simulations coupled to the MMGBSA approach of avian N1 type NA in its monomeric and tetrameric closed and open‐loop state both with and without the inhibitor oseltamivir and its natural substrate, sialic acid. Structural and energetic analyses revealed that the tetrameric state impacts flexibility as well as the map of interactions participating in stabilizing the protein–ligand complexes with respect to the monomeric state. It was observed that the tetrameric state exerts dissimilar effects in binding affinity, characteristic of positive and negative cooperativity for oseltamivir and sialic acid, respectively. Based on our results, to perform a confident structure‐based drug design, as well as to evaluate the impact of key mutations through MD simulations, it is important to consider the tetrameric state closed‐loop state.
Smart Design of Small‐Molecule Libraries: When Organic Synthesis Meets Cheminformatics
Authors: Lenci Elena , Trabocchi Andrea 
Published: December 2018

AbstractSynthetic chemists are always looking for new methods to maximize the diversity and complexity of small‐molecule libraries. Diversity‐oriented synthesis can give access to new chemotypes with high chemical diversity, exploiting complexity‐generating reactions and divergent approaches. However, there is a need for new tools to drive synthetic efforts towards unexplored and biologically relevant regions of chemical space. Because the number of publicly accessible biological data will increase in the years to come, cheminformatics can represent a real opportunity to develop better chemical libraries. This minireview focuses on novel cheminformatics approaches used to design molecular scaffolds, as well as to analyze their quality, giving a perspective of them in the field of chemical biology and drug discovery through some selected case studies.
Identifying the Biosynthetic Gene Cluster for Triacsins with an N‐Hydroxytriazene Moiety
Authors: Twigg Frederick F. , Cai Wenlong , Huang Wei , Liu Joyce , Sato Michio , Perez Tynan J. , Geng Jiaxin , Dror Moriel J. , Montanez Ismael , Tong Tate L. , Lee Hyunsu , Zhang Wenjun 
Published: December 2018

AbstractTriacsins are a family of natural products having in common an N‐hydroxytriazene moiety not found in any other known secondary metabolites. Though many studies have examined the biological activity of triacsins in lipid metabolism, their biosynthesis has remained unknown. Here we report the identification of the triacsin biosynthetic gene cluster in Streptomyces aureofaciens ATCC 31442. Bioinformatic analysis of the gene cluster led to the discovery of the tacrolimus producer Streptomyces tsukubaensis NRRL 18488 as a new triacsin producer. In addition to targeted gene disruption to identify necessary genes for triacsin production, stable isotope feeding was performed in vivo to advance the understanding of N‐hydroxytriazene biosynthesis.
Sintering and Coke Resistant Core/Yolk Shell Catalyst for Hydrocarbon Reforming
Authors: Li Ziwei , Wang Zhigang , Kawi Sibudjing 
Published: December 2018

AbstractSyngas/hydrogen production via hydrocarbon reforming reactions is crucial. Whereas, they need high reaction temperature to obtain economically feasible hydrocarbon conversions, which renders the active and cheap transition metal based catalysts easy to be sintered, leading to the high carbon deposition rate and gradual degradation of catalytic performance. Therefore, developing sintering and carbon resistant catalysts becomes one of the most important issues for these reforming reactions to be industrially applied. Designing catalysts with core/yolk shell structure turns out to be one of the most effective strategies to solve this issue. Herein, recent progress which has been made in the synthesis method for core/yolk shell catalysts with different shell materials such as SiO2, zeolite, CeO2 and Al2O3 is summarized. Additionally, specific applications of these core/yolk catalysts for various hydrocarbon reforming reactions such as dry reforming, steam reforming and methane oxidation are reviewed with the emphasis on revealing the reasons leading to their outstanding catalytic performance. Lastly, possible research directions in core/yolk shell catalysts are proposed.
Enhanced Oxygen Reduction Activity on Carbon Supported Pd Nanoparticles Via SiO2
Authors: Bao Zhikang , Zhou Hu , Song Xin , Gao Yijing , Zhuang Guilin , Deng Shengwei , Wei Zhongzhe , Zhong Xing , Wang Jianguo 
Published: December 2018

AbstractTo improve Pd‐based catalysts activity and stability is still challenge although Pd‐based catalysts have attracted attention for oxygen reduction reaction (ORR) during recent years. In this study, we have prepared supported Pd on SiO2, in which conductive carbon was used by coprecipitation method Pd/SiO2@C or physically mixed Pd/SiO2.Pd/SiO2@C (10 wt%) owned more outstanding catalytic activity, preferable durability, and stronger methanol tolerance capability in alkaline solution for ORR, which compared with commercial Pt/C (20 wt%) and Pd/C catalysts. We analyzed the morphology and electronic properties of the catalyst by SEM, TEM, XRD and XPS. It was found that the introduction of SiO2 changed the electronic structure of palladium, resulting in the production of electron‐rich Pd NPs, which was further confirmed by density functional theory calculations. Therefore, the introducing a small amount of SiO2 plays a vital role in facilitating the ORR activity of Pd‐based catalysts, which may be a new strategy to design new ORR catalysts and replace Pt‐based catalysts in fuel.
Electrochemical Abatement of Analgesic Antipyretic 4‐Aminophenazone using Conductive Boron‐Doped Diamond and Sub‐Stoichiometric Titanium Oxide Anodes: Kinetics, Mineralization and Toxicity Assessment
Authors: Ganiyu Soliu O. , Oturan Nihal , Trellu Clément , Raffy Stéphane , Cretin Marc , Causserand Christel , Oturan Mehmet A. 
Published: December 2018

AbstractThe oxidation ability of two prominent eco‐friendly electrochemical advanced oxidation processes (EAOPs), namely anodic oxidation with H2O2 generation (AO‐H2O2) and electro‐Fenton (EF) for complete abatement of acidic solution of 4‐aminophenazone (4‐APZ) has been investigated using conductive boron‐doped diamond (BDD) and sub‐stoichiometric titanium oxide (Ti4O7) anodes and carbon‐felt cathode. The higher performance of EF compared to AO‐H2O2 with either anode was demonstrated. In all trials, 4‐APZ was completely destroyed, following pseudo first‐order kinetics with the rate constant values increasing with applied current and higher values attained with BDD compared to Ti4O7 anode at similar conditions. The absolute rate constant for the reaction between 4‐APZ and hydroxyl radicals was found to be 3.9±0.2×109 L mol−1 s−1. Complete mineralization could be attained with BDD anode, whereas Ti4O7 anode only showed excellent mineralization up to 94 % TOC removal. Therefore, Ti4O7 anode can constitutes a promising anode material thanks to its lower manufacturing cost. Inorganic ions like NO3− and HCO3− at concentration up to 25 mM has no effect on mineralization efficiency during AO‐H2O2, but the presence of Cl− even at lower concentration of 10 mM significantly reduced the TOC removal efficiency. The toxicity of the solution sharply increased at initial stage of treatment, corresponding to the formation of cyclic by‐products but their conversion to carboxylic acids due to longer treatment time involved a sharp toxicity decrease, thus ensuring overall detoxification.
Synthesis of All Stereoisomers of RK460 and Evaluation of Their Activity and Selectivity as Abscisic Acid Receptor Antagonists
Authors: Mikame Yu , Yoshida Kazuko , Hashizume Daisuke , Hirai Go , Nagasawa Kazuo , Osada Hiroyuki , Sodeoka Mikiko 
Published: December 2018

AbstractThe PYR/PYL/RCAR protein families have recently emerged as receptors of the phytohormone abscisic acid (ABA, 1), which regulates plant responses to environmental stress. These families have multiple members with different physiological actions, and so selective agonists or antagonists are needed both as tools to elucidate functional differences and as lead compounds for agrochemicals. We previously identified RK460 (rac‐3 a) as a PYR1‐selective antagonist, and showed that it possesses five stereocenters on a 6,5‐cis‐bicyclo skeleton. Here, we synthesized all the stereoisomers of RK460 and evaluated their activity towards a panel of receptors. Relative stereochemistry as well as absolute stereochemistry was important for selective action.
Covalent Surface Functionalization of Calcium Phosphate Nanoparticles with Fluorescent Dyes by Copper‐Catalysed and by Strain‐Promoted Azide‐Alkyne Click Chemistry
Authors: Rojas‐Sánchez Leonardo , Sokolova Viktoriya , Riebe Steffen , Voskuhl Jens , Epple Matthias 
Published: December 2018

AbstractSpherical calcium phosphate nanoparticles with a solid core diameter around 90 nm (from scanning electron microscopy, SEM) were coated with a silica shell and then covalently functionalized by azide groups. To these azide groups, all kinds of alkyne‐carrying molecules can be covalently attached by copper‐catalysed azide‐alkyne cycloaddition (CuAAC) and by strain‐promoted azide‐alkyne cycloaddition (SPAAC) at a very high density. This was demonstrated for a number of dyes (FAM, TAMRA, Cy5, Alexa Fluor™ 488, and an aromatic thioether with aggregation‐induced emission (AIE) properties). It was also possible to attach more than one molecule to the surface of one particle by two‐step click reaction, permitting the synthesis of multimodal nanoparticles that are stable under biological conditions. The nanoparticles have a hydrodynamic diameter of around 200 nm (from dynamic light scattering, DLS), which makes them suitable for uptake by cells. The strongly fluorescing nanoparticles were easily taken up by cells as demonstrated by fluorescence microscopy, confocal laser scanning microscopy (CLSM), and structured illuminated microscopy (SIM).
Discovering Transcriptional Regulatory Elements From Run‐On and Sequencing Data Using the Web‐Based dREG Gateway
Authors: Chu Tinyi , Wang Zhong , Chou Shao‐Pei , Danko Charles G. 
Published: December 2018

AbstractTranscription is a chromatin mark that can be used effectively to identify the location of active enhancers and promoters, collectively known as transcriptional regulatory elements (TREs). We recently introduced dREG, a tool for the identification of TREs using run‐on and sequencing (RO‐seq) assays, including global run‐on and sequencing (GRO‐seq), precision run‐on and sequencing (PRO‐seq), and chromatin run‐on and sequencing (ChRO‐seq). In this protocol, we present step‐by‐step instructions for running dREG on an arbitrary run‐on and sequencing dataset. Users provide dREG with bigWig files (in which each read is represented by a single base) representing the location of RNA polymerase in a cell or tissue sample of interest, and dREG returns a list of genomic regions that are predicted to be active TREs. Finally, we demonstrate the use of dREG regions in discovering transcription factors controlling response to a stimulus and predicting their target genes. Together, this protocol provides detailed instructions for running dREG on arbitrary run‐on and sequencing data. © 2018 by John Wiley & Sons, Inc.
Does corporate social responsibility encourage sustainable innovation adoption?Empirical evidence fromLuxembourg
Authors: Poussing Nicolas 
Published: December 2018

AbstractThis contribution explores how corporate social responsibility (CSR) might influence the adoption of sustainable innovation. Previous research reveals that CSR effects depend on the specific CSR practices considered; this study accordingly investigates different measures of CSR practices with a strategic perspective: strategic versus responsive CSR. The empirical analysis is based on a survey carried out in Luxembourg in 2008, pertaining to CSR practices in firms, combined with the Community Innovation Survey of 2012. The results gathered from a sample of 286 firms, obtained with a Heckman procedure, highlight the importance of differentiating CSR strategies. Specifically, the results show that CSR activities in general do not lead to sustainable innovation adoption, but strategic CSR can have an effect on its adoption.
Compressive spectrum sensing using chaotic matrices for cognitive radio networks
Authors: Kamel Sara H. , Abd‐el‐Malek Mina B. , El‐Khamy Said E. 
Published: December 2018

SummaryCompressive sensing is an emerging technique in cognitive radio systems, through which sub‐Nyquist sampling rates can be achieved without loss of significant information. In collaborative spectrum sensing networks with multiple secondary users, the problem is to find a reliable and fast sensing method and to secure communication between members of the same network. The method proposed in this paper provides both quick and reliable detection through compressive sensing and security through the use of deterministic chaotic sensing matrices. Deterministic matrices have an advantage over random ones since they are easier to generate and store. Moreover, it is much easier to verify whether a deterministic matrix satisfies the conditions for compressive sensing compared with random matrices, which is what makes them an interesting area of research in compressive sensing. Also, it would be a great advantage if the sensing matrices also provide inherent security, which is the motivation for using chaotic matrices in this paper, since any slight changes in the chaotic parameters result in highly uncorrelated chaotic sequences, hence entirely different sensing matrices. This makes it impossible to reconstruct the signal without proper knowledge of the parameters used to generate the sensing matrix. They can also be easily regenerated by knowing the correct initial values and parameters. Additionally, new modifications are proposed to the existing structures of chaotic matrices. The performance of chaotic sensing matrices for both existing and modified structures is compared with that of random sensing matrices.
Metastatic granular cell tumor to the breast diagnosed by fine needle aspiration cytology: A case report with review of the literature
Authors: Mir Fatima , Alnajar Hussein , Rohra Prih , Naumaan Anam , Cheng Lin , Gattuso Paolo 
Published: December 2018

AbstractGranular cell tumors (GCT) are mesenchymal neoplasms of Schwann cell/neural origin. Malignant granular cell tumors (MGCTs) represent <1‐2% of all GCT and defined as tumors demonstrating metastases or destructive local growth. Other clinical parameters suggestive of malignancy include rapid growth, size > 4 cm and necrosis. An apparently inconsistent set of histological features have been described in MGCT. Although the histologic parameters of a GCT are not always predictive of biologic behavior, the presence of atypical features may be indicative of an aggressive clinical behavior (recurrence and metastases). A preoperative estimate of features suggestive of malignancy is important for treatment and prognostication. Diagnosis and prognostication from preoperative fine needle aspiration (FNA) cytology is hampered by the fact that only a few case reports on cytologic features of malignant GCT have been published. We report a case of metastatic MGCT to breast and compare cytologic features to that of primary breast GCT and apocrine/histiocytoid variants of breast carcinoma.
An empirical investigation of botnet as a service for cyberattacks
Authors: Hammi Badis , Zeadally Sherali , Khatoun Rida 
Published: December 2018

AbstractDuring the last years, cloud computing has emerged and imposed itself as a cost‐effective solution for providing high quality Information Technology services. However, beyond a legitimate usage, the benefits of cloud computing are being exploited by attackers in nefarious ways and botnets are among the greatest beneficiaries of this malicious use. This botnet trend is a major issue because it strongly increases the power of massive distributed attacks when leveraging the capabilities of cloud service providers that do not have appropriate detection approaches in place to detect botnets exploiting cloud resources (also referred to as botclouds). We developed a free experimental intra–Cloud Service Provider (CSP) botnet that exploits CSPs' trial versions. We used this intra‐CSP botnet to execute numerous TCP SYN flood and UDP flood attacks during one week. Our empirical results demonstrate that, contrary to what CSPs claim, all the CSPs (with the exception of one) we have tested still cannot detect or issued no warnings when malicious activities were launched from their cloud computing platforms. Besides, CSP's trial versions can easily be exploited to perpetrate large scale cyberattacks. We argue that efficient, cost‐effective, scalable detection approaches that can detect botclouds need to be developed in the future to address this challenge.
Improving momentum strategies using residual returns and option‐implied information
Authors: Liu Ming‐Yu 
Published: December 2018

AbstractThis paper provides an alternative method for enhancing momentum profits by combining residual returns and option‐implied information. The results show that the main benefit of applying residual returns to construct momentum portfolios is generating stable returns. Additionally, the incorporation of implied volatility (IV) spread or IV skew into a residual momentum portfolio is found to significantly raise profits, particularly during bad times and high‐sentiment periods. This is because IV spread and IV skew can dissociate winners/losers with a price underreaction from those with a price overreaction, which suggests that informed traders who perceive price underreactions/overreactions trade in option markets.
Associative memory for conceptually unitized word pairs in mild cognitive impairment is related to the volume of the perirhinal cortex
Authors: Delhaye Emma , Mechanic‐Hamilton Dawn , Saad Laura , Das Sandhitsu R. , Wisse Laura E. M. , Yushkevich Paul A. , Wolk David A. , Bastin Christine 
Published: December 2018

AbstractUnitization, that is, the encoding of an association as one integrated entity, has been shown to improve associative memory in populations presenting with associative memory deficit due to hippocampal dysfunction, such as amnesic patients with focal hippocampal lesions and healthy older adults. One reason for this benefit is that encoding of unitized associations would rely on the perirhinal cortex (PrC) and thus minimize the need for hippocampal recruitment. Mild cognitive impairment (MCI) is accompanied by a deficit in associative memory. However, unitization has never been studied to explore the potential benefit in associative memory in MCI, maybe because MCI is characterized by PrC pathology. However, the PrC may potentially still function sufficiently to allow for the successful adoption of unitization. In this study, we aimed at assessing whether unitization could attenuate MCI patients' associative memory deficit, and whether the ability to remember unitized associations would be modulated by the integrity of the PrC in MCI patients. Unitization was manipulated at a conceptual level, by encouraging participants to encode unrelated word pairs as new compound words. Participants also underwent a structural MRI exam, and measures of PrC were extracted (Brodmann Areas [BA] 35 and 36). Results showed that, contrary to healthy controls, MCI patients did not benefit from unitization. Moreover, their memory performance for unitized associations was related to the measure of PrC integrity (BA35), while it was not the case in controls. This finding thus suggests that unitization does not help to attenuate the associative deficit in MCI patients, and brings support to the literature linking unitization to the PrC function.
Different propolis samples, phenolic content, and breast cancer cell lines: Variable cytotoxicity ranging from ineffective to potent
Authors: Seyhan Mehmet Fatih , Yılmaz Eren , Timirci‐Kahraman Özlem , Saygılı Neslihan , Kısakesen Halil İbrahim , Gazioğlu Sema , Gören Ahmet C. , Eronat Allison Pınar , Begüm Ceviz A. , Öztürk Tülin , Yılmaz‐Aydoğan Hülya , Öztürk Oğuz 
Published: December 2018

ABSTRACTResearchers have started focusing on investigating the anticarcinogenic effects of natural products with the slightest side effects possible, because current breast cancer treatment approaches are unable to achieve absolute success especially on aggressive subtypes. Propolis is among these products with its antimicrobial, antifungal, anti‐inflammatory, and anticancer effects. Therefore, seven different samples were collected from different regions (Argentina, China, and Istanbul‐Turkey) and applied on nonaggressive breast cancer cell line (BCCL) MCF‐7 and aggressive cell lines SK‐BR‐3, and MDA‐MB‐231. Initially, the phenolic/flavonoid constituents of the propolis ethanol extracts were investigated by liquid chromatography‐mass spectrometry–mass spectrometry (LS‐MS/MS) and high‐performance liquid chromatography (HPLC) analyses. Then, the anticarcinogenic effects of the propolis samples on MCF‐7, SK‐BR‐3, MDA‐MB‐231 were evaluated by WST1 analysis and only selected ones on MCF‐10A and hPdLF. According to the LS‐MS/MS and HPLC analysis, Turkey originated propolis (Turkey3) were found to be richer than the other propolis samples in terms of phenolic/flavonoid compounds. Turkey propolis significantly inhibited cell proliferation in both nonaggressive and aggressive BCCL (P < 0.01). Therefore, Turkey3 propolis was selected for further evaluation using Annexin V‐PI apoptosis detection assays. In addition, selected compounds among the propolis contents such as galangin, caffeic acid, apigenin, quercetin, and ferulic acid were applied to the MCF‐7 cell line to detect cytotoxic and apoptotic effects. Galangin, caffeic acid, apigenin, and quercetin remarkably induced cell proliferation inhibition at all time intervals, whereas ferulic acid was found non efficient on the MCF‐7 cell line. Annexin V‐PI assay clarified that all cell proliferation inhibitions were markedly apoptotic. Our findings indicated that the inhibition effect of propolis on breast cancer cell proliferation was in a propolis type‐, dose‐ and time‐dependent fashion. Turkey3 propolis showed statistically significant cytotoxic effects on both the nonaggressive and aggressive BCCL. These findings were consistent with the effects of its rich phenolic and flavonoid contents, in terms of variety. © 2018 IUBMB Life, 71(5):619–631, 2019