bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Annulative Synthetic Strategy for Building Triphenylene Frameworks by Multiple C−H Bond Activations
Authors: Mathew Bijoy P. , Yang Hyun Ji , Kim Joohee , Lee Jae Bin , Kim Yun‐Tae , Lee Sungmin , Lee Chang Young , Choe Wonyoung , Myung Kyungjae , Park Jang‐Ung , Hong Sung You 
Published: March 2017

AbstractC−H activation is a versatile tool for appending aryl groups to aromatic systems. However, heavy demands on multiple catalytic cycle operations and site‐selectivity have limited its use for graphene segment synthesis. A Pd‐catal‐ yzed one‐step synthesis of functionalized triphenylene frameworks is disclosed, which proceeds by 2‐ or 4‐fold C−H arylation of unactivated benzene derivatives. A Pd2(dibenzylideneacetone)3 catalytic system, using cyclic diaryliodonium salts as π‐extending agents, leads to site‐selective inter‐ and intramolecular tandem arylation sequences. Moreover, N‐substituted triphenylenes are applied to a field‐effect transistor sensor for rapid, sensitive, and reversible alcohol vapor detection.
Struktur und Biosynthese der Isatropolone, bioaktiver und Amin‐reaktiver fluoreszierender Naturstoffe aus Streptomyces Gö66
Authors: Cai Xiaofeng , Shi Yi‐Ming , Pöhlmann Nicole , Revermann Ole , Bahner Isabel , Pidot Sacha J. , Wesche Frank , Lackner Helmut , Büchel Claudia , Kaiser Marcel , Richter Christian , Schwalbe Harald , Stinear Timothy P. , Zeeck Axel , Bode Helge B. 
Published: March 2017

AbstractDie Naturstoffe Isatropolon A–C (1–3) wurden aus Streptomyces Gö66 reisoliert, und insbesondere 1 und 3 zeigen sehr gute Aktivität gegen Leishmania donovani. Sie tragen einen ungewöhnlichen Tropolonring, der über einen Typ‐II‐Polyketid‐Biosyntheseweg aufgebaut wird. Ihre Biosynthese wurde mithilfe von Markierungsexperimenten, einer Analyse des Biosynthese‐Genclusters, heterologer Expression des Hauptteils des Genclusters und strukturelle Charakterisierung verschiedener Intermediate aufgeklärt. Aufgrund eines 1,5‐Diketon‐Strukturelementes können die Isatropolone mit Ammoniak und Aminen und insbesondere Lysin sowie Lysin‐tragenden Peptiden und Proteinen reagieren und einen Pyridinring bilden. Dabei ändern sich die Fluoreszenz‐Eigenschaften so deutlich, dass die so markierten Peptide und Proteine sehr einfach sichtbar gemacht werden können.
Formation of an Isolable Divinylborinium Ion through Twofold 1,2‐Carboboration between a Diarylborinium Ion and Diphenylacetylene
Authors: Tanaka Naoki , Shoji Yoshiaki , Hashizume Daisuke , Sugimoto Manabu , Fukushima Takanori 
Published: March 2017

AbstractBorinium ions, that is, two‐coordinate boron cations, are the most electron‐deficient isolable boron compounds. As borinium ions have only four formal valence electrons on boron, they should show a strong tendency to accept electron pairs on the boron atom to fill its valence shell. Thus chemical reactions of borinium ions are expected to give products in which the coordination number of boron is increased from two to three or four. However, contrary to this expectation, we found that the dimesitylborinium ion (Mes2B+) undergoes twofold 1,2‐carboboration reactions with two equivalents of diphenylacetylene to yield an unprecedented borinium ion (1+) with two substituted vinyl groups on the boron center. NMR spectroscopy and X‐ray diffraction analysis of 1+, together with electronic‐structure calculations, revealed that the positive charge is delocalized over the entire π‐conjugated system. The fact that the chemical transformation of a borinium ion gives rise to a different borinium ion without a change in the coordination number is remarkable and should provide new insight into the chemistry of the Group 13 elements.
Structure and Biosynthesis of Isatropolones, Bioactive Amine‐Scavenging Fluorescent Natural Products from Streptomyces Gö66
Authors: Cai Xiaofeng , Shi Yi‐Ming , Pöhlmann Nicole , Revermann Ole , Bahner Isabel , Pidot Sacha J. , Wesche Frank , Lackner Helmut , Büchel Claudia , Kaiser Marcel , Richter Christian , Schwalbe Harald , Stinear Timothy P. , Zeeck Axel , Bode Helge B. 
Published: March 2017

AbstractThe natural products isatropolone A–C (1–3) were reisolated from Streptomyces Gö66, with 1 and 3 showing potent activity against Leishmania donovani. They contain a rare tropolone ring derived from a type II polyketide biosynthesis pathway. Their biosynthesis was elucidated by labeling experiments, analysis of the biosynthesis gene cluster, its partial heterologous expression, and structural characterization of various intermediates. Owing to their 1,5‐diketone moiety, they can react with ammonia, amines, lysine, and lysine‐containing peptides and proteins, which results in the formation of a covalent bond and subsequent pyridine ring formation. Their fluorescence properties change upon amine binding, enabling the simple visualization of reacted amines including proteins.
A facile one‐step synthesis of flame‐retardant coatings on cotton fabric via ultrasound irradiation
Authors: Liang Tianyuan , Jiang Zhenlin , Wang Chaosheng , Liu Jialin 
Published: March 2017

ABSTRACTThis article reports a facile one‐step methodology to increase fire resistance properties of cotton fabric. The flame‐retardant coating for cotton fabric was synthesized with methyltriethoxysilane and organophosphates (M102B) through an ultrasound irradiation process. The coating structure and surface morphology of uncoated and coated fabrics were investigated by Fourier transform infrared spectroscopy and scanning electron microscope, respectively. The flame‐retardant properties, bending modulus, air permeability and thermal stability were studied by vertical burning test, cantilever method, air permeability test and thermogravimetric analysis (TGA). As a result, the cotton fabric coated with 29.2% (mass increased) of flame‐retardant coating was able to balance the flame retardant property and wearing comfort of the fabrics. The TGA results showed that the residue char of cotton was greatly enhanced after treatment with the coating, which has a high char forming effect on cellulose during testing. Furthermore, flame‐retardant property of coated fabrics did not change significantly after 10 washing cycles. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45114.
Improved cell morphology and thermal properties of expanded polypropylene beads by the addition of PP with a high melting point
Authors: Zhang Rong , Xiong Yezhi , Liu Qingting , Hu Shengfei 
Published: March 2017

ABSTRACTExpanded polypropylene (EPP) beads have attracted attention in recent years due to their potential use in fabricating complex, three dimensional structures. In this study, a small amount of polypropylene (PP) with a higher melting temperature (HPP) was blended with low melting point PP (LPP) to regulate the cell morphology and thermal behavior peaks of the resulting blends. These materials were then foamed to produce EPP beads in an autoclave with CO2 at different temperatures, producing EPP beads. The rheological, thermal, and foaming properties of the LPP/HPP blends were characterized. The melt strength and elasticity of LPP/HPP were improved because of rapid crystallization and increase in crystal number with increasing HPP content. These results were attributed to the physical crosslinks and nucleation sites provided by the HPP. These enhanced properties were leveraged to produce regular foams without through‐holes, decreased cell size, and increased cell density. Furthermore, the lower melting point decreased with increasing HPP content, producing a wider temperature range over which steam‐chest molding could occur. Thus, the addition of HPP is a facile method for regulating the cell morphology and thermal behavior of EPP. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45121.
Factors driving spatial variation in egg survival of an ecologically and culturally important forage fish
Authors: Keeling Britt , Hessing‐Lewis Margot , Housty Clark , Okamoto Daniel K. , Gregr Edward J. , Salomon Anne K. 
Published: March 2017

AbstractLow trophic‐level forage fish are experiencing global declines, influencing coupled human–ocean systems worldwide. Along the northwest coast of North America, declining trajectories of Pacific herring (Clupea pallasii) have prompted interest in improving the understanding of its population and community dynamics to better guide future conservation and management strategies.To improve future population estimates and understanding of the ecological factors governing herring egg survival, the magnitude, spatial variation and mechanisms driving herring egg loss rates were quantified. This was achieved by way of repeated observational field surveys and a predator exclusion experiment.Observational surveys revealed that regional egg loss rates (Z) were substantial and ranged from 0.101 ± 0.019 to 0.134 ± 0.028, the equivalent of 88–94% egg loss over a 21 day incubation period, or 50–60% egg loss over 6.8 days, the average time lag between spawn deposition and annual egg surveys. Furthermore, spatial variation was high, with egg loss rates varying 5‐fold among study sites. Depth, time since spawn, and spawn area were primary spatial drivers of egg loss, but predator abundance and exposure were secondarily important.Experimental evidence showed that benthic predation and habitat type were strong drivers of egg loss, suggesting that a high proportion of eggs, particularly those spawned on benthic substrates, are consumed by predators.These results have important conservation implications for managers and ecologists seeking to estimate herring biomass and to understand the environmental influences on predator–prey interactions that affect herring dynamics.
Invasive Chinese pond mussel Sinanodonta woodiana threatens native mussel reproduction by inducing cross‐resistance of host fish
Authors: Donrovich Seth W. , Douda Karel , Plechingerová Věra , Rylková Kateřina , Horký Pavel , Slavík Ondřej , Liu Huan‐Zhang , Reichard Martin , Lopes‐Lima Manuel , Sousa Ronaldo 
Published: March 2017

Abstract

The effects of invasive alien species (IAS) on host–affiliate relationships are often subtle and remain unnoticed or insufficiently quantified. The global decline of freshwater unionid mussel species has been attributed to many causes, but little is known about the interactions of IAS, with their complex life cycle, which includes an obligatory parasitic stage (the glochidium) that develops on fishes.
The capacity of a European freshwater mussel, Anodonta anatina, to develop on its widespread fish host, Squalius cephalus was tested experimentally, after previous infestations by the IAS, Sinanodonta (Anodonta) woodiana. The initial attachment of glochidia, the length of the parasitic period, and the metamorphosis success rate of A. anatina glochidia were compared among treatments of different priming infestation intensities.
The metamorphosis success rate of the native A. anatina glochidia was strongly reduced (Wilcoxon Signed‐Rank Test, P < 0.001) and declined by 42.1 and 45.4% on fish hosts that were previously exposed to S. woodiana by single and multiple priming infestations, respectively, in comparison with the control group. Such cross‐resistance is expected to decrease significantly the quality of the host resources available to native mussels.
This study provides the first evidence of the host‐mediated adverse impact of invasive S. woodiana on native mussel species. These results also highlight the importance of potential competition for hosts between threatened groups of affiliate species and their invasive counterparts, which should be reflected in conservation strategies.
Assessing the impacts of tourism on the world's largest fish Rhincodon typus at Panaon Island, Southern Leyte, Philippines
Authors: Araujo Gonzalo , Vivier Fabien , Labaja Jessica June , Hartley Daniel , Ponzo Alessandro 
Published: March 2017

Abstract

Shark‐based tourism is a rapidly growing industry, particularly with whale sharks, as new hotspots are identified worldwide. Understanding any impacts of tourism is essential to minimize any potential detrimental effects on the target species and habitat.
In‐water behavioural observations of whale sharks were used to understand any impacts of tourism at a small site in Panaon Island, Southern Leyte, Philippines. A generalized linear mixed model was fitted to test anthropogenic and environmental variables, with interaction duration as the response variable, to assess any disturbance to the animals by the tourism activities.
Whale sharks were observed between the months of November and June between 2013 and 2016, with highly variable seasons. In total, 527 tourist‐whale shark interactions were recorded during 359 trips identifying 104 individual whale sharks, most of which were juvenile males (85%, measuring c. 5.5 m total length). Proximity of motorized vessels and interactions in deeper waters were found to significantly shorten interactions. Short‐term behavioural changes were observed in response to human events (e.g. touching). Interactions when whale sharks were feeding were significantly longer than when they were not. Individual behavioural variability was observed.
Impacts could be mitigated with small managerial changes and increased enforcement, such as limiting the number of motorized vessels and the number of people around the whale sharks. Although no long‐term impacts were recorded during this study, it is difficult to ascertain this in a long‐lived, wide‐ranging species.
This knowledge gap highlights the need to build long‐term monitoring programmes, and to apply the precautionary principle for the sustainable use of this endangered species.
Remote refrigeration system experiments for control engineering education
Authors: Rampazzo Mirco , Cervato Andrea , Beghi Alessandro 
Published: March 2017

ABSTRACTThe extension of the traditional hands‐on laboratories to the Internet, in which labs are remotely accessible to the users to perform experiments, is still a challenge for education in engineering. In this paper, we present a remote refrigeration laboratory that allows students, trainees, and engineers to get acquainted with control aspects of mechanical refrigeration systems. Thanks to a university–industry partnership, the remote lab is hosted in an industrial site and it can be accessed by means of a client–server communication and an ad‐hoc designed LabVIEW‐based user interface, that allows to monitor and control the plant. The user can conduct both open‐ and closed‐loop experiments on a typical vapor compression cycle refrigeration system, testing different control architectures that range from standard regulators to data‐driven PID controllers.© 2017 Wiley Periodicals, Inc. Comput Appl Eng Educ 25:430–440, 2017; View this article online at wileyonlinelibrary.com/journal/cae; DOI 10.1002/cae.21810
Design of a low cost remote electronic laboratory suitable for low bandwidth connection
Authors: Mostefaoui Hakima , Benachenhou Abdelhalim , Benattia Abderrahmane Adda 
Published: March 2017

ABSTRACTThe development of remote lab has grown during the last decade. However, almost all current laboratories use proprietary software (a Labview like software) and expensive hardware (server) to implement them. This paper presents the development of a low‐cost alternative, flexible, and reconfigurable remote lab, based on an architecture built around an Arduino Mega. Low‐bandwidth connections requirement was carried out by the use of HTML code for the development of the required graphical user interface. The usability and effectiveness of the proposed solutions were evaluated by considering a case study of two groups of students that carried out the same lab work: The first one remotely and the second one in a hands‐on lab. This test showed that the remote laboratory was well received by students: Remote students group realize their task in a shorter time and have slightly better outcomes than students group in a hands‐on laboratory. © 2017 Wiley Periodicals, Inc. Comput Appl Eng Educ 25:480–488, 2017; View this article online at wileyonlinelibrary.com/journal/cae; DOI 10.1002/cae.21815
Electrochemical Biosensors: Electrode Development, Materials, Design, and Fabrication
Authors: Abdulbari Hayder A. , Basheer Esmail A. M. 
Published: March 2017

AbstractThis paper reviews the engineering design of an electrochemical biosensor, particularly the main concepts of electrodes and the type of material selections, design, and fabrication method. Furthermore, the related theories and practical examples from existing literature are reviewed. Research is now directed toward the development of biosensors as important bioanalytical tools in the pharmaceutical, biotechnology, food, and other consumer‐oriented industries. Currently, comprehensive guidelines on the selection of electrodes for electrochemical biosensors are unavailable. Factual options are important in determining the real‐time response of biosensors. Attempts to determine the best material and design for electrodes have no results because of the complexity of fabrication and the lifespan of the material chosen for the electrodes. This paper summarizes the trends in numerous studies on developing electrochemical biosensors. A better understanding of biosensors will greatly assist in the design of new and improved biosensors.
Quantitative Evaluation of Passive Scalar Flow Mixing – A Review of Recent Developments
Authors: Xu Ben , Li Yuchun , Xu Xiankun , Xu Xinhai 
Published: March 2017

AbstractFlow mixing has always been of particular interest for chemical engineering, combustion, and energy industries as well as other related engineering applications. Mixing always plays a crucial role because of its ability to uniformly distribute the passive scalar in the flow field without dynamic influences to the flow field itself. This paper reviews studies which quantitatively evaluated passive scalar mixing in various engineering applications. On the one hand, passive scalar mixing in turbulence has been reviewed from the aspect of energy spectrum cascades and small temporal‐spatial scale analysis, mixing time, unmixedness, mixing time‐scale ratio, and relative mixing intensity ratio using DNS. Secondly, several different concepts (percentage mixing, mixing intensity and degree of mixing) to quantify the flow mixing in microfluidic systems were introduced and compared thoroughly, and it is believed that these methods can be extended to other macro fluid engineering systems. Furthermore, a CFD‐based approach using the statistics of temporal and spatial distribution of fluid particles was reviewed, but cannot be extended to engineering applications with special requirements of mixing time.
The Cell‐Surface N‐Glycome of Human Embryonic Stem Cells and Differentiated Hepatic Cells thereof
Authors: Montacir Houda , Freyer Nora , Knöspel Fanny , Urbaniak Thomas , Dedova Tereza , Berger Markus , Damm Georg , Tauber Rudolf , Zeilinger Katrin , Blanchard Véronique 
Published: March 2017

AbstractHuman embryonic stem cells (hESCs) are pluripotent stem cells that offer a wide range of applications in regenerative medicine. In addition, they have been proposed as an appropriate alternative source of hepatocytes. In this work, hESCs were differentiated into definitive endodermal cells (DECs), followed by maturation into hepatocyte‐like cells (HLCs). Their cell‐surface N‐glycome was profiled and also compared with that of primary human hepatocytes (PHHs). Undifferentiated hESCs contained large amounts of high‐mannose N‐glycans. In contrast, complex‐type N‐glycans such as asialylated or monosialylated biantennary and triantennary N‐glycans were dominant in HLCs, and fully galactosylated structures were significantly more abundant than in undifferentiated hESCs. The cell‐surface N‐glycosylation of PHHs was more biologically processed than that of HLCs, with bisialylated biantennary and trisialylated triantennary structures predominant. This is the first report of the cell surface N‐glycome of PHHs and of HLCs being directly generated from hESCs without embryoid body formation.
A Tandem Enzymatic sp2‐C‐Methylation Process: Coupling in Situ S‐Adenosyl‐l‐Methionine Formation with Methyl Transfer
Authors: Sadler Joanna C. , Humphreys Luke D. , Snajdrova Radka , Burley Glenn A. 
Published: March 2017

AbstractA one‐pot, two‐step biocatalytic platform for the regiospecfic C‐methylation and C‐ethylation of aromatic substrates is described. The tandem process utilises SalL (Salinospora tropica) for in situ synthesis of S‐adenosyl‐l‐methionine (SAM), followed by alkylation of aromatic substrates by the C‐methyltransferase NovO (Streptomyces spheroides). The application of this methodology is demonstrated for the regiospecific labelling of aromatic substrates by the transfer of methyl, ethyl and isotopically labelled 13CH3, 13CD3 and CD3 groups from their corresponding SAM analogues formed in situ.
Indications of 5′ to 3′ Interbase Electron Transfer as the First Step of Pyrimidine Dimer Formation Probed by a Dinucleotide Analog
Authors: Jian Yajun , Maximowitsch Egle , Liu Degang , Adhikari Surya , Li Lei , Domratcheva Tatiana 
Published: March 2017

AbstractPyrimidine dimers are the most common DNA lesions generated under UV radiation. To reveal the molecular mechanisms behind their formation, it is of significance to reveal the roles of each pyrimidine residue. We thus replaced the 5′‐pyrimidine residue with a photochemically inert xylene moiety (X). The electron‐rich X can be readily oxidized but not reduced, defining the direction of interbase electron transfer (ET). Irradiation of the XpT dinucleotide under 254 nm UV light generates two major photoproducts: a pyrimidine (6‐4) pyrimidone analog (6‐4PP) and an analog of the so‐called spore photoproduct (SP). Both products are formed by reaction at C4=O of the photo‐excited 3′‐thymidine (T), which indicates that excitation of a single “driver” residue is sufficient to trigger pyrimidine dimerization. Our quantum‐chemical calculations demonstrated that photo‐excited 3′‐T accepts an electron from 5′‐X. The resulting charge‐separated radical pair lowers its energy upon formation of interbase covalent bonds, eventually yielding 6‐4PP and SP.
Gold(I)‐Catalyzed Cycloisomerization of ortho‐(Propargyloxy)arenemethylenecyclopropanes Controlled by Adjacent Substituents at Aromatic Rings
Authors: Fang Wei , Wei Yin , Tang Xiang‐Ying , Shi Min 
Published: March 2017

AbstractGold(I)‐catalyzed cycloisomerization of ortho‐(propargyloxy)arenemethylenecyclopropanes afforded two different types of products, that is, products of methylenecyclopropane migration and cycloisomerization products of the methylenecyclopropane moiety, controlled jointly by electronic and steric effects of the adjacent substituents. Furthermore, the corresponding cycloisomerization products could be also produced in an enantiomerically enriched manner.
Synthesis of Poly‐γ‐S‐2‐methylbutyl‐l‐glutamate and Poly‐γ‐S‐2‐methylbutyl‐d‐glutamate and Their Use as Enantiodiscriminating Alignment Media in NMR Spectroscopy
Authors: Hansmann Stefanie , Schmidts Volker , Thiele Christina M. 
Published: March 2017

AbstractLyotropic liquid crystalline (LLC) phases of polyglutamic acid derivatives, such as poly‐γ‐benzyl‐l‐glutamate, are suitable alignment media for organic structure elucidation by NMR spectroscopy. Their helical structure is responsible for enantiodiscrimination. As part of our ongoing investigations concerning the alignment mechanism(s) of these systems, we considered whether an additional chiral center in the side chain could improve enantiodiscrimination relative to the helical polymer with an achiral side chain. Therefore, the diastereoisomers poly‐γ‐S‐2‐methylbutyl‐l‐glutamate (PSMBLG) and poly‐γ‐S‐2‐methylbutyl‐d‐glutamate (PSMBDG) were synthesized. These two polymers were tested for their liquid crystallinity and suitability as alignment media. The spatial structure of the solutes (−)‐curcumol and isopinocampheol (IPC) were validated by the residual dipolar coupling data obtained. Additionally, enantiodiscrimination of IPC was observed in the new alignment media and compared with the enantiodiscrimination of IPC in other homopolypeptides.