bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fractal Coding Metamaterials
Authors: Moeini Samaneh , Cui Tie Jun 
Published: December 2018

AbstractThe concept of fractal coding metamaterials is proposed here, which can be used to design reflective metasurfaces with self‐similar pseudo‐random phase responses based on the coding strategy utilizing fractal interpolation functions (FIF). The class of fractals whose FIF is formed by a contraction mapping on the y‐coordinate and an arbitrary linear function of the x‐coordinate is considered. This formulation is used in deriving the theoretical model and in the experimental realization. An analytical relation between the reflection phase distribution in the form of the above‐mentioned FIF and the far‐field radiation pattern of the structure is derived. In the numerical example, a reflecting metasurface formed by slotted metallic patches of varying sizes is considered. A number of full wave scattering simulations for such a metamaterial reflectarray are performed and the optimal designs which make the response of the structure more accurate as compared with the analytical predictions are identified. Following the simulation results, the array is built and a number of measurements are performed. The results of this work may find applications in phased antenna array design and beam forming.
Constraining Exotic Interactions
Authors: Ficek Filip , Budker Dmitry 
Published: December 2018

AbstractBeyond‐the‐standard‐model interactions mediated by an exchange of virtual “new” bosons result in a finite set of possible effective interaction potentials between standard‐model particles such as electrons and nucleons. The classification of such potentials is discussed and recent experiments searching for such exotic interactions at spatial scales from sub‐nanometers to tens of thousand kilometers are briefly reviewed.
The Planck Constant for the Definition and Realization of the Kilogram
Authors: Wood Barry , Bettin Horst 
Published: December 2018

AbstractOn May 20, 2019 the values of the Planck, h, and Avogadro, NA, constants will be fixed, revising our measurement system, the International System of Units (SI), and providing a new way to get mass traceability. While the famous energy relations mc2 and hf may remind many that the Planck constant is indeed related to mass, it is less recognized how this is also true for the Avogadro constant. These concepts are reviewed in the context of the upcoming revision of the SI. How the fixed values were chosen and how mass traceability will be maintained with the smallest uncertainty are also discussed.
Gasotransmitter Regulation of Phosphatase Activity in Live Cells Studied by Three‐Channel Imaging Correlation
Authors: Ou Pan , Zhang Ruilong , Liu Zhengjie , Tian Xiaohe , Han Guangmei , Liu Bianhua , Hu Zhangjun , Zhang Zhongping 
Published: December 2018

AbstractEnzyme activity in live cells is dynamically regulated by small‐molecule transmitters for maintaining normal physiological functions. A few probes have been devised to measure intracellular enzyme activities by fluorescent imaging, but the study of the regulation of enzyme activity via gasotransmitters in situ remains a long‐standing challenge. Herein, we report a three‐channel imaging correlation by a single dual‐reactive fluorescent probe to measure the dependence of phosphatase activity on the H2S level in cells. The two sites of the probe reactive to H2S and phosphatase individually produce blue and green fluorescent responses, respectively, and resonance energy transfer can be triggered by their coexistence. Fluorescent analysis based on the three‐channel imaging correlation shows that cells have an ideal level of H2S to promote phosphatase activity up to its maximum. Significantly, a slight deviation from this H2S level leads to a sharp decrease of phosphatase activity. The discovery further strengthens our understanding of the importance of H2S in cellular signaling and in various human diseases.
Kontrolle über Kettenvernetzung und Einzelkettenverknüpfung durch zwei Farben des sichtbaren Lichts
Authors: Frisch Hendrik , Bloesser Fabian R. , Barner‐Kowollik Christopher 
Published: December 2018

AbstractWährend photochemische Synthese den Zugang zu orts‐ und zeitaufgelöster Reaktionskontrolle ermöglicht, ist ihr Potential spezifische Reaktionen mit einer bestimmten Farbe des Lichts auszulösen durch omnipräsente spektrale Überlappe der reaktiven Gruppen limitiert. Nachfolgend wird ein neues Konzept vorgestellt, das aktiv eine von zwei Ligationsreaktionen unterdrückt, indem die Cycloreversion der [2+2]‐Cycloaddition des Styrylpyrens induziert wird. Die Kombination dieser photoreversiblen Chemie und der [4+4]‐Cycloaddition des 9‐Triazolylanthracens ermöglicht es zuerst eine Kettenkupplung unter Verwendung von UV‐Licht zu initiieren und anschließend den daraus hervorgehenden Einzelketten‐Nanopartikel (single chain nanoparticle, SCNP) mit einer zweiten Polymerkette unter Verwendung von blauem Licht zu ligieren. Durch erstmals erreichte sequenzunabhängige λ‐orthogonale Reaktivität konnte dieselbe makromolekulare Architektur in der umgekehrten Bestrahlungssequenz erhalten werden, indem zuerst mit blauem Licht und darauffolgend mit violettem Licht bestrahlt wurde – ohne jegliche Verwendung von harschem UV‐Licht.
Dissoziation schwacher Säuren über den gesamten Molenbruchbereich
Authors: Blasius Jan , Ingenmey Johannes , Perlt Eva , von Domaros Michael , Hollóczki Oldamur , Kirchner Barbara 
Published: December 2018

AbstractWir präsentieren am Beispiel von in Wasser gelöster Ameisensäure und Essigsäure, dass der Ansatz der binären Quantum‐Cluster‐Equilibrium‐(bQCE)‐Theorie die Säurestärke über den gesamten Konzentrationsbereich vorhersagen kann. Wir zeigen über einen Molenbruchbereich von 0 bis 0.7, dass die molenbruchabhängige Säurestärke nicht mit simplen Annahmen beschrieben werden kann. Hierin spiegelt sich das komplexe Zusammenspiel verfügbarer dissoziierter Ionen oder konjugierter Basen mit vorhandenen Säure‐ und Wassermolekülen wider. Zusätzlich können unsere berechneten Ionenkonzentrationen das experimentelle Leitfähigkeitsmaximum der Essigsäure mit hervorragender, das der Ameisensäure mit zufriedenstellender Genauigkeit beschreiben. Da für die Ergebnisse nur eine geringe Anzahl an einfachen, quantenchemischen Berechnungen notwendig ist, eignet sich die bQCE‐Theorie als neuer und nützlicher Ansatz, um Eigenschaften nichtwässriger Lösungen vorherzusagen. Die Methode ist außerdem in der Lage, Ionisationsprozesse in hochkonzentrierten Lösungen zu beschreiben, die sowohl für chemische und biologische Systeme wie auch für technologische Prozesse von großer Relevanz sind.
Introducing the Petasis Reaction for Late‐Stage Multicomponent Diversification, Labeling, and Stapling of Peptides
Authors: Ricardo Manuel G. , Llanes Dayma , Wessjohann Ludger A. , Rivera Daniel G. 
Published: December 2018

AbstractFor the first time, the Petasis (borono‐Mannich) reaction is employed for the multicomponent labeling and stapling of peptides. The report includes the solid‐phase derivatization of peptides at the N‐terminus, Lys, and Nϵ‐MeLys side‐chains by an on‐resin Petasis reaction with variation of the carbonyl and boronic acid components. Peptides were simultaneously functionalized with aryl/vinyl substituents bearing fluorescent/affinity tags and oxo components such as dihydroxyacetone, glyceraldehyde, glyoxylic acid, and aldoses, thus encompassing a powerful complexity‐generating approach without changing the charge of the peptides. The multicomponent stapling was conducted in solution by linking Nϵ‐MeLys or Orn side‐chains, positioned at i, i+7 and i, i+4, with aryl tethers, while hydroxy carbonyl moieties were introduced as exocyclic fragments. The good efficiency and diversity oriented character of these methods show prospects for peptide drug discovery and chemical biology.
Controlling Chain Coupling and Single‐Chain Ligation by Two Colours of Visible Light
Authors: Frisch Hendrik , Bloesser Fabian R. , Barner‐Kowollik Christopher 
Published: December 2018

AbstractWhile photochemical synthesis offers access to spatiotemporal reaction control, its potential to selectively address specific reactions by the colour of light is usually limited by ubiquitous spectral absorption overlaps of the reactive groups. Herein, a new concept is introduced that actively suppresses one ligation reaction by triggering the cycloreversion of the [2+2] cycloaddition of styrylpyrene. Combination of the photoreversible styrylpyrene chemistry with the [4+4] cycloaddition of 9‐triazolylanthracene makes it possible to initially induce chain coupling using UV light and to subsequently ligate the formed single‐chain nanoparticle (SCNP) with a second polymer chain using blue light. Seizing upon the first sequence‐independent λ‐orthogonal reactivity established here, the same macromolecular architecture was obtained in reverse irradiation sequence, by blue and subsequent violet light irradiation—completely foregoing high‐energy UV light.
Predicting Mole‐Fraction‐Dependent Dissociation for Weak Acids
Authors: Blasius Jan , Ingenmey Johannes , Perlt Eva , von Domaros Michael , Hollóczki Oldamur , Kirchner Barbara 
Published: December 2018

AbstractWe demonstrate for formic and acetic acid dissolved in water as examples that the binary quantum cluster equilibrium (bQCE) approach can predict acid strengths over the whole range of acid concentrations. The acid strength increases in a complex rather than a simple way with increasing mole fraction of the acid from 0 to 0.7, reflecting the complex interplay between the dissociated ions or conjugate bases available as compared to the acid and water molecules. Furthermore, our calculated ion concentrations meet the experimental maximum of the conductivity with excellent agreement for acetic acid and satisfactorily for the formic acid/water mixture. As only a limited number of simple quantum‐chemical calculations are required for the prediction, bQCE is clearly a valuable approach to access these quantities also in non‐aqueous solutions. It is a highly valuable asset for predicting ionization processes in highly concentrated solutions, which are relevant for biological and chemical systems, as well as technological processes.
DNA methyltransferase BmDnmt1 and BmDnmt2 in silkworm (Bombyx mori) and the regulation of silkworm embryonic development
Authors: Li Bing , Hu Pei , Zhang Shang‐Zhi , Toufeeq Shahzad , Wang Jie , Zhao Kang , Xu Xin , Xu Jia‐Ping , Huang Shou‐Jun 
Published: December 2018

AbstractDNA methylation is one of the most widespread epigenetic marks and has been linked to insect development, especially influencing embryonic development. However, the regulation of DNA methylation in silkworm embryonic development and diapause remain to investigate. In this study, reverse‐transcription quantitative polymerase chain reaction was performed to identify the expression level of Bombyx mori DNA methyltransferases (BmDNMTs) 1 and 2 (
BmDnmt1 and
BmDnmt2) in different tissues, different embryonic developmental stages, and different strains of the silkworm. The results showed that
BmDNMTs were the most highly expressed during embryonic development, especially at early embryonic stages. In particular, the expression of BmDNMTs was significantly upregulated in diapause‐terminated eggs by HCl treatment. Moreover, tissue distribution showed that
BmDnmt2 was highly expressed in testis and ovary, and
BmDnmt1 was highly expressed in testis. This study contributes to understanding the correlation of DNA methylation occurs with embryogenesis and gametogenesis in insect, meanwhile, it provides a research orientation to further analyze the role of DNA methylation in diapause initiation and termination in insect embryonic development.
Purification and characterization of phenoloxidase from the hemolymph of healthy and diseasedAntheraea assamensisHelfer (Lepidoptera: Saturniidae): Effects of certain biological components and chemical agents on enzyme activity
Authors: Baruah Gayatri Sarma , Sarma Hridip Kumar , Bardoloi Sunayan , Bora Dipsikha 
Published: December 2018

AbstractIn the current study, a dimeric phenoloxidase (PO) from the hemolymph of healthy and diseased (pebrine infected) larvae ofAntheraea assamensisHelfer was extracted and purified. The protein was subjected to purification using Sephacryl S‐100 and CM Sepharose chromatography. The enzyme comprised of two subunits of ~76.8 and 76 kDa that showed PO activity in 6 mMl‐3,4‐dihydroxyphenylalanine (L‐DOPA) and 8 mM catechol but not in hydroquinone. Optimum temperature for PO activity was 30°C inl‐DOPA and 37°C in catechol. Optimum pH ranged from 6.8 to 7.0 inL‐DOPA and 7.0–7.2 in catechol. Specific activity of the purified PO from healthy larvae was 53.9 µM/min per mg of protein per ml inL‐DOPA and 50.77 µM/min per mg of protein per ml in catechol. Specific activity of PO from diseased larvae was 30.0 µM/min per mg of protein per ml inL‐DOPA and 28.55 µM/min per mg of protein per ml in catechol. Purification fold was 3.27–4.21 for healthy and 2.38–2.56 for diseased fractions. The enzyme showed the Michaelis constant (Km) of 2.46–2.85 mM for healthy and diseased fractions inL‐DOPA. In catecholKmof 9.23–17.71 mM was observed. Peptidoglycan was the best activator of purified PO from both healthy and diseased fractions. Interactions between controls and activators appeared statistically significant (F = 767.5;df = 3;P < 0.0001). Na+, K+, and Cu2+increased, whereas Ca2+, Zn2+, Mg2+, and Co2+decreased PO activity. The overall interactions appeared highly significant (F = 217.0;df = 27;P < 0.0001). Kojic acid, dithiothreitol, thiourea, phenylthiourea, carbendazim,N‐bromosuccinimide,N,N,N′,N′‐tetraacetic acid, and diethyldithiocarbamate inhibited PO activity.
Light/Palladium‐Promoted Benzylic C−H Acylation Using a Benzoyl Group as the Photo‐Directing Group
Authors: Masuda Yusuke , Ishida Naoki , Murakami Masahiro 
Published: December 2018

Abstract2‐Methylphenyl ketones undergo site‐selective acylation at the benzylic position when treated with acid anhydride under UV irradiation in the presence of a palladium catalyst. The benzoyl carbonyl group serves as the photo‐directing group so that the ortho benzylic C−H bond is activated site‐selectively.
Cytoprotective, anti‐inflammatory, and antioxidant properties of high‐molecular‐weight hyaluronan enriched with red orange extract in human fibroblasts exposed to ultra violet light B irradiation
Authors: Penna Ilaria , Albanesi Ennio , Bertorelli Rosalia , Bandiera Tiziano , Russo Debora 
Published: December 2018

AbstractUltraviolet (UV) light exposure is the primary factor responsible for skin photoaging, affecting all the skin layers, mainly through the production of reactive oxygen species (ROS), activation of inflammatory responses, and apoptosis. In keeping with this evidence, exogenous supplementation with dietary antioxidants has been shown to provide photoprotective benefits. Moreover, oral administration of hyaluronic acid (HA) has been proved to reduce the signs of aged skin, such as wrinkles, and increase hydration and elasticity. The combination of different biologically active substances in order to slow down the onset of skin aging could represent a promising preventive strategy against photoaging. In the present study, we investigated the effects of a dietary supplement (IALUTEC® RED), consisting of high‐molecular‐weight HA (HMW‐HA) combined with red orange extract (ROC‐Red Orange Complex®), in human fibroblasts exposed to ultra violet light B‐induced oxidative stress. Our study suggests that, in fibroblasts exposed to UVB light, IALUTEC® RED is active in decreasing both the inflammatory response and the generation of ROS, two events that are involved in skin photoaging.
Goodness‐of‐fit tests for disorder detection in NGS experiments
Authors: Jiménez‐Otero Norman , de Uña‐Álvarez Jacobo , Pardo‐Fernández Juan Carlos 
Published: December 2018

AbstractNext‐generation sequencing (NGS) experiments are often performed in biomedical research nowadays, leading to methodological challenges related to the high‐dimensional and complex nature of the recorded data. In this work we review some of the issues that arise in disorder detection from NGS experiments, that is, when the focus is the detection of deletion and duplication disorders for homozygosity and heterozygosity in DNA sequencing. A statistical model to cope with guanine/cytosine bias and phasing and prephasing phenomena at base level is proposed, and a goodness‐of‐fit procedure for disorder detection is derived. The method combines the proper evaluation of localp‐values (one for each DNA base) with suitable corrections for multiple comparisons and the discrete nature of thep‐values. A global test for the detection of disorders in the whole DNA region is proposed too. The performance of the introduced procedures is investigated through simulations. A real data illustration is provided.
Conceptualizing businesses as social actors: A framework for understanding sustainability actions in small‐ and medium‐sized enterprises
Authors: Westman Linda , Luederitz Christopher , Kundurpi Aravind , Mercado Alexander Julian , Weber Olaf , Burch Sarah Lynne 
Published: December 2018

AbstractSmall‐ and medium‐sized enterprises (SMEs) can play a crucial role in advancing environmental and social well‐being. Yet various—often conflicting—explanations have been offered to clarify why SMEs pursue sustainability. Some arguments foreground possibilities of profit maximization, whereas others emphasize individual values and convictions. Research supporting such contradicting explanations is often biased towards large enterprises or small, innovative frontrunners. In this article, we examine the underlying drivers of social and environmental interventions of SMEs by exploring empirical data from a survey of over 1,600 Canadian SMEs and complementary in‐depth interviews. We argue that sustainability actions of SMEs can be understood by viewing these firms as social actors—organizations that are shaped by individual values, internal and external interpersonal relationships, and are embedded in a social environment. This conceptualization directs attention to the full range of factors that shape sustainability engagement of SMEs and highlights frequently overlooked forms of sustainability‐oriented actions.
Engineering the Mycomembrane of Live Mycobacteria with an Expanded Set of Trehalose Monomycolate Analogues
Authors: Fiolek Taylor J. , Banahene Nicholas , Kavunja Herbert W. , Holmes Nathan J. , Rylski Adrian K. , Pohane Amol Arunrao , Siegrist M. Sloan , Swarts Benjamin M. 
Published: December 2018

AbstractMycobacteria and related organisms in the Corynebacterineae suborder are characterized by a distinctive outer membrane referred to as the mycomembrane. Biosynthesis of the mycomembrane occurs through an essential process called mycoloylation, which involves antigen 85 (Ag85)‐catalyzed transfer of mycolic acids from the mycoloyl donor trehalose monomycolate (TMM) to acceptor carbohydrates and, in some organisms, proteins. We recently described an alkyne‐modified TMM analogue (O‐AlkTMM‐C7) which, in conjunction with click chemistry, acted as a chemical reporter for mycoloylation in intact cells and allowed metabolic labeling of mycoloylated components of the mycomembrane. Here, we describe the synthesis and evaluation of a toolbox of TMM‐based reporters bearing alkyne, azide, trans‐cyclooctene, and fluorescent tags. These compounds gave further insight into the substrate tolerance of mycoloyltransferases (e.g., Ag85s) in a cellular context and they provide significantly expanded experimental versatility by allowing one‐ or two‐step cell labeling, live cell labeling, and rapid cell labeling via tetrazine ligation. Such capabilities will facilitate research on mycomembrane composition, biosynthesis, and dynamics. Moreover, because TMM is exclusively metabolized by Corynebacterineae, the described probes may be valuable for the specific detection and cell‐surface engineering of Mycobacterium tuberculosis and related pathogens. We also performed experiments to establish the dependence of probe incorporation on mycoloyltransferase activity, results from which suggested that cellular labeling is a function not only of metabolic incorporation (and likely removal) pathway(s), but also accessibility across the envelope. Thus, whole‐cell labeling experiments with TMM reporters should be carefully designed and interpreted when envelope permeability may be compromised. On the other hand, this property of TMM reporters can potentially be exploited as a convenient way to probe changes in envelope integrity and permeability, facilitating drug development studies.
Breaking the Fourth Wall: Modulating Quaternary Associations for Protein Regulation and Drug Discovery
Authors: Long Marcus J. C. , Hnedzko Dziyana , Kim Bo Kyoung , Aye Yimon 
Published: December 2018

AbstractProtein–protein interactions (PPIs) are an effective means to orchestrate intricate biological processes required to sustain life. Approximately 650 000 PPIs underlie the human interactome; thus underscoring its complexity and the manifold signaling outputs altered in response to changes in specific PPIs. This minireview illustrates the growing arsenal of PPI assemblies and offers insights into how these varied PPI regulatory modalities are relevant to customized drug discovery, with a focus on cancer. First, known and emerging PPIs and PPI‐targeted drugs of both natural and synthetic origin are categorized. Building on these discussions, the merits of PPI‐guided therapeutics over traditional drug design are discussed. Finally, a compare‐and‐contrast section for different PPI blockers, with gain‐of‐function PPI interventions, such as PROTACS, is provided.
Bacterially Derived Antibody Binders as Small Adapters for DNA‐PAINT Microscopy
Authors: Schlichthaerle Thomas , Ganji Mahipal , Auer Alexander , Kimbu Wade Orsolya , Jungmann Ralf 
Published: December 2018

AbstractCurrent optical super‐resolution implementations are capable of resolving features spaced just a few nanometers apart. However, translating this spatial resolution to cellular targets is limited by the large size of traditionally employed primary and secondary antibody reagents. Recent advancements in small and efficient protein binders for super‐resolution microscopy, such as nanobodies or aptamers, provide an exciting avenue for the future; however, their widespread availability is still limited. To address this issue, here we report the combination of bacterial‐derived binders commonly used in antibody purification with DNA‐based point accumulation for imaging in nanoscale topography (DNA‐PAINT) microscopy. The small sizes of these protein binders, relative to secondary antibodies, make them an attractive labeling alternative for emerging superresolution techniques. We present here a labeling protocol for DNA conjugation of bacterially derived proteins A and G for DNA‐PAINT, having assayed their intracellular performance by targeting primary antibodies against tubulin, TOM20, and the epidermal growth factor receptor (EGFR) and quantified the increases in obtainable resolution.