bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of S‐Adenosyl‐L‐Methionine Analogs with Extended Transferable Groups for Methyltransferase‐Directed Labeling of DNA and RNA
Authors: Masevičius Viktoras , Nainytė Milda , Klimašauskas Saulius 
Published: March 2016

Abstract
S‐Adenosyl‐L‐methionine (AdoMet) is a ubiquitous methyl donor for a variety of biological methylation reactions catalyzed by methyltransferases (MTases). AdoMet analogs with extended propargylic chains replacing the sulfonium‐bound methyl group can serve as surrogate cofactors for many DNA and RNA MTases enabling covalent deposition of these linear chains to their cognate targets sites in DNA or RNA. Here we describe synthetic procedures for the preparation of two representative examples of AdoMet analogs with a transferable hex‐2‐ynyl group carrying a terminal azide or amine functionality. Our approach is based on direct chemoselective alkylation of S‐adenosyl‐L‐homocysteine at sulfur with corresponding nosylates under acidic conditions. We also describe synthetic routes to 6‐substituted hex‐2‐yn‐1‐ols and their conversion to the corresponding nosylates. Using these protocols, synthetic AdoMet analogs can be prepared within 1 to 2 weeks. © 2016 by John Wiley & Sons, Inc.
Preparation of High‐Density Fibrillar Collagen Matrices That Mimic Desmoplastic Tumor Stroma
Authors: Artym Vira V. 
Published: March 2016

AbstractThe stroma of invasive tumors becomes enriched in dense fibrillar collagen as a result of the desmoplastic reaction. This desmoplastic collagen exerts profound effects on tumor and normal cells. In view of these findings, it is important to develop novel in vitro cell systems that mimic this desmoplastic extracellular matrix in order to permit cell studies under in vivo−like conditions. This unit provides a protocol and troubleshooting guide for preparation of high‐density fibrillar collagen (HDFC) matrices that closely model the desmoplastic collagenous matrix of malignant tumors. It then describes the use of this matrix for in vitro cell studies of invadopodia formation and function in extracellular matrix invasion. In addition, it provides a detailed protocol for immunolabeling of invadopodial proteins and detection of HDFC matrix degradation associated with invadopodia to permit visualization of invadopodia using fluorescence microscopy. © 2016 by John Wiley & Sons, Inc.
Seasonality of photochemical dissolved organic carbon mineralization and its relative contribution to pelagic CO2 production in northern lakes
Authors: Vachon Dominic , Lapierre Jean‐François , del Giorgio Paul A. 
Published: March 2016

AbstractBoreal and northern temperate lakes (hereinafter referred to as northern lakes) are sites of intense processing of dissolved organic carbon (DOC), which is reflected in part in the persistent CO2 supersaturation of their surface waters. These ecosystems are subject to strong seasonal fluctuations in both irradiance and DOC amount and quality, which in turn should result in temporal shifts in the magnitude of DOC photodegradation. Here we explore the temporal patterns in the magnitude of water column DOC photomineralization and its potential contribution to pelagic CO2 production in three northern lakes of different DOC content. We performed laboratory DOC photodegradation incubations and combined the resulting rates with field measurements and modeling to reconstruct the annual cycle in depth‐integrated DOC photomineralization. We found that areal rates of DOC photomineralization were driven by both irradiance and intrinsic DOC photoreactivity, both of which showed seasonality. Over an annual cycle, depth‐integrated DOC photomineralization rates were remarkably similar across lakes, averaging 4.4 (SD = 0.7) g C m−2 yr−1 and daily rates followed an apparent seasonal pattern. The contribution of DOC photomineralization to total pelagic CO2 production (as the sum of respiration and DOC photomineralization) peaked after ice melt (up to 49%), averaging 14% for the entire open water season. Our study identifies potential hot periods of photochemical activity that result from the interplay between DOC properties and environmental conditions, which should be incorporated into models of lake functioning.
Commentary on “Atmospheric ionization by high‐fluence, hard‐spectrum solar proton events and their probable appearance in the ice core archive” by A.L. Melott et al. and “Nitrate ion spikes in ice cores not suitable as proxies for solar proton events” by K.A. Duderstadt et al.
Authors: Sinnhuber M. 
Published: March 2016

Key Points

Comment on Duderstadt et al. and Melott et al.
Both come to different conclusions, though they agree in key points
The main reason for the disagreement seems to be different assumptions made
Generating Mouse Models Using CRISPR‐Cas9‐Mediated Genome Editing
Authors: Qin Wenning , Kutny Peter M. , Maser Richard S. , Dion Stephanie L. , Lamont Jeffrey D. , Zhang Yingfan , Perry Greggory A. , Wang Haoyi 
Published: March 2016

AbstractThe CRISPR‐Cas9 system in bacteria and archaea has recently been exploited for genome editing in various model organisms, including mice. The CRISPR‐Cas9 reagents can be delivered directly into the mouse zygote to derive a mutant animal carrying targeted genetic modifications. The major components of the system include the guide RNA, which provides target specificity, the Cas9 nuclease that creates the DNA double‐strand break, and the donor oligonucleotide or plasmid carrying the intended mutation flanked by sequences homologous to the target site. Here we describe the general considerations and experimental protocols for creating genetically modified mice using the CRISPR‐Cas9 system. © 2016 by John Wiley & Sons, Inc.
Heterogeneous Preferences for Domestic Fresh Produce: Evidence from German and Italian Early Potato Markets
Authors: Colantuoni Francesca , Cicia Gianni , Del Giudice Teresa , Lass Daniel , Caracciolo Francesco , Lombardi Pasquale 
Published: March 2016

ABSTRACTIn this research, we explore the market potential of a domestic agricultural product, the early potato, in two countries, Italy and Germany. We conducted two parallel marketing studies aimed at revealing the most desirable characteristics for the commercialization of this product in each of the two markets, and made comparisons among consumers’ attitudes for several attributes (country of origin, carbon footprint, production method, ethical certification and packaging). Motivation for this study is the declining market share of the domestic early potato, considered an important crop in both countries, due to the competition from abroad. A focal aspect of this research is the recent public interest for social justice, traditionally reserved for products imported from developing countries, with respect to ethical products made in developed countries. The possibility for Italian and German early potatoes to regain important market shares depends on the ability to differentiate their potatoes from potatoes supplied by competing extra‐European countries. [JEL Classifications: Q13; Q18].
More than metabolic: Considering the broader paleoepidemiological impact of vitamin D deficiency in bioarchaeology
Authors: Snoddy Anne Marie E , Buckley Hallie R , Halcrow Siân E 
Published: March 2016

ABSTRACTVitamin D deficiency has traditionally been viewed as a metabolic bone disease by bioarchaeologists and considered primarily in terms of the development of specific musculoskeletal changes used for diagnosis in paleopathological research. These skeletal manifestations are usually interpreted as representing general ill‐health. Clinical research shows that vitamin D is also integral to a number of extra‐skeletal physiological processes including immunoregulation, blood pressure homeostasis, cell division, and programmed cell death. Vitamin D deficiency and sub‐clinical insufficiency are thought to be risk factors for infectious and autoimmune diseases, as well as certain cancers and cardiovascular diseases. Epidemiological work indicates that the skeletal manifestations of vitamin D deficiency represent the extreme end of a spectrum of morbidity associated with negative health outcomes, including increased risk for secondary tuberculosis. This article provides a review of clinical research on the extra‐skeletal roles of vitamin D and the pathological consequences of poor vitamin D status. Additionally, it presents an interpretive model for bioarchaeological analyses of rickets and osteomalacia for consideration of the whole‐body impact of poor vitamin D nutriture and possible comorbidities that may have affected the wider population. Am J Phys Anthropol 160:183–196, 2016. © 2016 Wiley Periodicals, Inc.
Outcome and recurrence 1 year after pediatric arterial ischemic stroke in a population‐based cohort
Authors: Mallick Andrew A. , Ganesan Vijeya , Kirkham Fenella J. , Fallon Penny , Hedderly Tammy , McShane Tony , Parker Alasdair P. , Wassmer Evangeline , Wraige Elizabeth , Amin Sam , Edwards Hannah B. , Cortina‐Borja Mario , O'Callaghan Finbar J. 
Published: March 2016

ObjectiveArterial ischemic stroke (AIS) is an important cause of acquired brain injury in children. Few prospective population‐based studies of childhood AIS have been completed. We aimed to investigate the outcome of childhood AIS 12 months after the event in a population‐based cohort.MethodsChildren aged 29 days to < 16 years with radiologically confirmed AIS occurring over a 1‐year period residing in southern England (population = 5.99 million children) were eligible for inclusion. Outcome was assessed during a home visit using the Pediatric Stroke Outcome Measure (PSOM). Parental impressions of recovery were assessed using the Pediatric Stroke Recurrence and Recovery Questionnaire. PSOM score was estimated via telephone interview or clinician interview whenever home visit was not possible.ResultsNinety‐six children with AIS were identified. Two children were lost to follow‐up. Nine of 94 (10%) children died before the 12‐month follow‐up. One child had an AIS recurrence. PSOM scores were available for 78 of 85 living children at follow‐up. Thirty‐nine of 78 (50%) had a good outcome (total PSOM score < 1), and 39 of 78 (50%) had a poor outcome. Seizures at onset of AIS were associated with a poor outcome (odds ratio = 3.5, 95% confidence interval = 1.16–10.6). Twenty‐eight of 73 (38%) children were judged by their carers to have fully recovered. Ten of 84 (12%) children had recurrent seizures, and 17 of 84 (20%) reported recurrent headaches.InterpretationAIS carries a significant risk of mortality and long‐term neurological deficit. However, the rates of mortality, recurrence, and neurological impairment were markedly lower in this study than previously published figures in the United Kingdom. Ann Neurol 2016;79:784–793
Use of Three‐Dimensional Arterial Models To Predict the In Vivo Behavior of Nanoparticles for Drug Delivery
Authors: Chetprayoon Paninee , Matsusaki Michiya , Yokoyama Utako , Tejima Takanori , Ishikawa Yoshihiro , Akashi Mitsuru 
Published: March 2016

AbstractNanomaterials have been widely used for applications in biomedical fields and could become indispensable in the near future. However, since it is difficult to optimize in vivo biological behavior in a 3D environment by using a single cell in vitro, there have been many failures in animal models. In vitro prediction systems using 3D human‐tissue models reflecting the 3D location of cell types may be useful to better understand the biological characteristics of nanomaterials for optimization of their function. Herein we demonstrate the potential ability of 3D engineered human‐arterial models for in vitro prediction of the in vivo behavior of nanoparticles for drug delivery. These models enabled optimization of the composition and size of the nanoparticles for targeting and treatment efficacy for atherosclerosis. In vivo experiments with atherosclerotic mice suggested excellent biological characteristics and potential treatment effects of the nanoparticles optimized in vitro.
Facile Conversion of Red Phosphorus into Soluble Polyphosphide Anions by Reaction with Potassium Ethoxide
Authors: Dragulescu‐Andrasi Alina , Miller L. Zane , Chen Banghao , McQuade D. Tyler , Shatruk Michael 
Published: March 2016

AbstractSoluble polyphosphide anions were successfully generated in a number of organic solvents by the reaction between shelf‐stable red phosphorus and potassium ethoxide. The species were identified by 31P NMR spectroscopy in solution and by X‐ray crystal‐structure determination of (Bu4N)2P16 in the solid state. The reaction was scaled up to gram quantities by using a flow‐chemistry process.
Chemoreactive Natural Products that Afford Resistance Against Disparate Antibiotics and Toxins
Authors: Du Lin , You Jianlan , Nicholas Kenneth M. , Cichewicz Robert H. 
Published: March 2016

AbstractMicroorganisms use chemical inactivation strategies to circumvent toxicity caused by many types of antibiotics. Yet in all reported cases, this approach is limited to enzymatically facilitated mechanisms that each target narrow ranges of chemically related scaffolds. The fungus‐derived shikimate analogues, pericoxide and pericosine A, were identified as chemoreactive natural products that attenuate the antagonistic effects of several synthetic and naturally derived antifungal agents. Experimental and computational studies suggest that pericoxide and pericosine A readily react via SN2′ mechanisms against a variety of nucleophilic substances under both in vitro aqueous and in situ co‐culture conditions. Many of the substitution products from this reaction were highly stable and exhibited diminished toxicities against environmental fungal isolates, including the Tolypocladium sp. strain that produced pericoxide and pericosine A.
Synthesis of Aryldifluoroamides by Copper‐Catalyzed Cross‐Coupling
Authors: Arlow Sophie I. , Hartwig John F. 
Published: March 2016

AbstractA copper‐catalyzed coupling of aryl, heteroaryl, and vinyl iodides with α‐silyldifluoroamides is reported. The reaction forms α,α‐difluoro‐α‐aryl amides from electron‐rich, electron‐poor, and sterically hindered aryl iodides in high yield and tolerates a variety of functional groups. The aryldifluoroamide products can be transformed further to provide access to a diverse array of difluoroalkylarenes, including compounds of potential biological interest.
Towards Truly Sustainable Polymers: A Metal‐Free Recyclable Polyester from Biorenewable Non‐Strained γ‐Butyrolactone
Authors: Hong Miao , Chen Eugene Y.‐X. 
Published: March 2016

AbstractThe first effective organopolymerization of the biorenewable “non‐polymerizable” γ‐butyrolactone (γ‐BL) to a high‐molecular‐weight metal‐free recyclable polyester is reported. The superbase tert‐Bu‐P4 is found to directly initiate this polymerization through deprotonation of γ‐BL to generate reactive enolate species. When combined with a suitable alcohol, the tert‐Bu‐P4‐based system rapidly converts γ‐BL into polyesters with high monomer conversions (up to 90 %), high molecular weights (Mn up to 26.7 kg mol−1), and complete recyclability (quantitative γ‐BL recovery).
Direct‐current conductivity at a cryogenically low temperature for polymer/carbon composites: Applicability of different theoretical models
Authors: Aldalbahi Ali , Rahaman Mostafizur , Kumar Chaki Tapan , Khastgir Dipak 
Published: March 2016

ABSTRACTIn this study, we focused on the behavior of the direct‐current (dc) conductivity/resistivity in a cryogenically low temperature region (10–300 K) for ethylene vinyl acetate copolymer, acrylonitrile butadiene copolymer, and their 50/50 blend composites filled with different conductive carbons. The composites were prepared through a melt‐mixing technique. Different behaviors of the dc resistivity/relative resistivity for the composites were observed; these behaviors depended on the nature of the polymers, the filler types, and the filler concentration when plotted with respect to the temperature. The results of dc conductivity were fitted with some existing theoretical models, including Arrhenius, Kivelson, and Mott's variable range hopping, to check their applicability for these composite systems. We observed that none of the models was applicable within the entire range of measurement temperatures but were confined within limited temperature ranges. The reason behind the nonapplicability of the models is discussed with consideration of their drawbacks and limitations. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43541.
Synthesis, Isolation and Structure of Trifluoromethylated Fullerene D3‐C78, C78(1)(CF3)10−18
Authors: Kosaya Maria P. , Fritz Maria A. , Brotsman Victor A. , Tamm Nadezhda B. , Ignat'eva Daria V. , Troyanov Sergey I. 
Published: March 2016

AbstractHigh‐temperature trifluoromethylation of fullerene C78 followed by HPLC separation of C78(CF3)n derivatives resulted in the isolation and X‐ray structural characterization of 15 compounds, that is, two C78(1)(CF3)10, three C78(1)(CF3)12, four C78(1)(CF3)14, and five C78(1)(CF3)16 isomers as well as one isomer of C78(1)(CF3)18. The addition patterns of the C78(1)(CF3)n molecules are discussed in terms of trifluoromethylation pathways and relative formation energies.
Efficient Synthesis of the Disialylated Tetrasaccharide Motif in N‐Glycans through an Amide‐Protection Strategy
Authors: Zhou Jiazhou , Manabe Yoshiyuki , Tanaka Katsunori , Fukase Koichi 
Published: March 2016

AbstractA disialylated tetrasaccharide, Neu5Ac(α2,3)Gal(β1,3)[Neu5Ac(α2,6)]GlcNAc (1), which is found at the termini of some N‐glycans, has been synthesized. Compound 1 was obtained through an α‐sialylation reaction between a sialic acid donor and a trisaccharide that was synthesized from the glycosylation of a sialylated disaccharide with a glucosaminyl donor. This synthetic route enabled the synthesis of the as‐described disialylated structure. A more‐convergent route based on the glycosylation of two sialylated disaccharides was also established to scale up the synthesis. Protection of the amide groups in the sialic acid residues significantly increased the yield of the glycosylation reaction between the two sialylated disaccharides, thus suggesting that the presence of hydrogen bonds on the sialic acid residues diminished their reactivity.
CTK‐II & RTK: The CCD‐cameras operated at the auxiiary telescopes of the University Observatory Jena
Authors: Mugrauer M. 
Published: March 2016

AbstractThe Cassegrain‐Teleskop‐Kamera (CTK‐II) and the Refraktor‐Teleskop‐Kamera (RTK) are two CCD‐imagers which are operated at the 25 cm Cassegrain and 20cm refractor auxiliary telescopes of the University Observatory Jena. This article describes the main characteristics of these instruments. The properties of the CCD‐detectors, the astrometry, the image quality, and the detection limits of both CCD‐cameras, as well as some results of ongoing observing projects, carried out with these instruments, are presented. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Stability of a planet in the HD 41004 binary system
Authors: Satyal S. , Musielak Z. E. 
Published: March 2016

AbstractThe Hill stability criterion is applied to analyse the stability of a planet in the binary star system of HD 41004 AB, with the primary and secondary separated by 22 AU, and masses of 0.7 M⊙ and 0.4 M⊙, respectively. The primary hosts one planet in an S‐type orbit, and the secondary hosts a brown dwarf (18.64 MJ) on a relatively close orbit, 0.0177 AU, thereby forming another binary pair within this binary system. This star‐brown dwarf pair (HD 41004 B+Bb) is considered a single body during our numerical calculations, while the dynamics of the planet around the primary, HD 41004 Ab, is studied in different phase‐spaces. HD 41004 Ab is a 2.6 MJ planet orbiting at the distance of 1.7 AU with orbital eccentricity 0.39. For the purpose of this study, the system is reduced to a three‐body problem and is solved numerically as the elliptic restricted three‐body problem (ERTBP). The Hill stability function is used as a chaos indicator to configure and analyse the orbital stability of the planet, HD 41004 Ab. The indicator has been effective in measuring the planet's orbital perturbation due to the secondary star during its periastron passage. The calculated Hill stability time series of the planet for the coplanar case shows the stable and quasi‐periodic orbits for at least ten million years. For the reduced ERTBP the stability of the system is also studied for different values of planet's orbital inclination with the binary plane. Also, by recording the planet's ejection time from the system or collision time with a star during the integration period, stability of the system is analysed in a bigger phase‐space of the planet's orbital inclination, ≤ 90°, and its semimajor axis, 1.65–1.75 AU. Based on our analysis it is found that the system can maintain a stable configuration for the planet's orbital inclination as high as 65° relative to the binary plane. The results from the Hill stability criterion and the planet's dynamical lifetime map are found to be consistent with each other. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Mattig's relation and dynamical distance indicators
Authors: Teerikorpi P. , Baryshev Yu. V. 
Published: March 2016

AbstractWe discuss how the redshift (Mattig) method in the Friedmann cosmology relates to dynamical distance indicators based on Newton's gravity (Teerikorpi 2011). It belongs to the class of indicators where the relevant length inside the system is the distance itself (in this case the proper metric distance). As the Friedmann model has a Newtonian analogy, its use to infer distances has instructive similarities to classical dynamical distance indicators. In view of the theoretical exact linear distance‐velocity law, we emphasize that it is conceptually correct to derive the cosmological distance via the route: redshift (primarily observed) → space expansion velocity (not directly observed) → metric distance (physical length in “cm”). Important properties of the proper metric distance are summarized. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Search for transiting exoplanets and variable stars in the open cluster NGC 7243
Authors: Garai Z. , Pribulla T. , Hambálek Ľ. , Errmann R. , Adam Ch. , Buder S. , Butterley T. , Dhillon V. S. , Dincel B. , Gilbert H. , Ginski Ch. , Hardy L. K. , Kellerer A. , Kitze M. , Kundra E. , Littlefair S. P. , Mugrauer M. , Nedoroščík J. , Neuhäuser R. , Pannicke A. , Raetz S. , Schmidt J. G. , Schmidt T. O. B. , Seeliger M. , Vaňko M. , Wilson R. W. 
Published: March 2016

AbstractWe report results of the first five observing campaigns for the open stellar cluster NGC 7243 in the frame of project Young Exoplanet Transit Initiative (YETI). The project focuses on the monitoring of young and nearby stellar clusters, with the aim to detect young transiting exoplanets and to study other variability phenomena on time‐scales from minutes to years. After five observing campaigns and additional observations during 2013 and 2014, a clear and repeating transit‐like signal was detected in the light curve of J221550.6+495611. Furthermore, we detected and analysed 37 new eclipsing binary stars in the studied region. The best fit parameters and light curves of all systems are given. Finally, we detected and analysed 26 new, presumably pulsating variable stars in the studied region. The follow‐up investigation of these objects, including spectroscopic measurements of the exoplanet candidate, is currently planned. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)