bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Nigerian Education Milieu in the SDG Era: The Roles, Values, Challenges and Prospects of ODL and Lifelong Learning
Authors: Osunwusi Adeyinka Olumuyiwa 
Published: March 2020

National governments are under increasing pressures to address issues surrounding sustainable development. Interestingly, considerable attention is shifting towards education, which has been widely recognized not only as a fundamental human right but also as a catalyst for sustainable development and a vehicle for confronting the challenges facing societies in terms of profound shifts in demographics as well as socio-economic, environmental and ecological realities. As a corollary, ODL and lifelong learning have equally been identified as constituting a force contributing to social and economic development. As a member of the United Nations, Nigeria is committed to achieving not only the human rights enshrined in the Universal Declaration of Human Rights of 1948 but also the Global Goals, especially SDG 4 on equitable quality education. This paper examines the UNESCO Sustainable Development Goals and explores, based on a review of extant literature, the conceptual and theoretical dimensions of ODL and lifelong learning in the context of their role, values, challenges and opportunities. The paper also outlines current trends in the context of the Nigerian education system and suggests policy, strategy and institutional considerations for mainstreaming ODL and lifelong learning for the purpose of achieving SDG 4. The review of related literature included a search of both published and conference papers and deployed systematic procedures for an exploration of perspectives and ideologies on the key issues of the Global Goals, sustainable development, education for sustainable development (ESD), ODL, and lifelong learning. The study revealed that while the Global Goals are enjoying increasing buy-ins, progress towards achieving the SDGs – particularly Goal 4 – has been unimpressive in many countries, particularly in sub-Saharan Africa. The study also identified trends, challenges and opportunities for integrating ESD in education, ODL and lifelong learning in Africa in general and Nigeria in particular. Based on an evaluation and analysis of perspectives, the study concluded that Nigeria is still a long way to achieving the SDGs. A number of suggestions were made towards a reasonable achievement of sustainable development goal 4, including the importance of: strengthening relevant constitutional framework on education; providing supportive policy and institutional frameworks; and integrating the philosophies of sustainable development in education and training at all levels.
The Origin of Tel Dor Hacksilver and the Westward Expansion of the Phoenicians in the Early Iron Age: The Cypriot Connection
Authors: Wood Jonathan R. , Bell Carol , Montero-Ruiz Ignacio 
Published: March 2020

Abstract
A recent reanalysis of compositional and lead isotope legacy data from the early silver hoards of the southern Levant (ca. twelfth–ninth centuries BCE) identified that not only was most of this hacksilver mixed but that it probably derived from the Pyritic belt of southern Iberia, the Taurus mountains in Anatolia, and a third unknown source. We propose that the unknown component of Tel Dor's hacksilver was silver potentially derived from ores mined at Kalavasos on Cyprus. The presence of Cypriot silver in the southern Levant complements finds of Phoenician pottery on Cyprus, supporting that there was continuity of trade from the end of the Bronze Age to the beginning of the Iron Age between Cyprus and the Levant. Furthermore, our findings suggest that the technology required to smelt and cupellate argentiferous jarosite ores was first practiced on Cyprus prior to risky and costly ventures to Iberia.
Hybrid Materials from Ultrahigh‐Inorganic‐Content Mineral Plastic Hydrogels: Arbitrarily Shapeable, Strong, and Tough
Authors: Zhang Xiaotong , Wu Baohu , Sun Shengtong , Wu Peiyi 
Published: March 2020

AbstractNatural mineralized structural materials such as nacre and bone possess a unique hierarchical structure comprising both hard and soft phases, which can achieve the perfect balance between mechanical strength and shape controllability. Nevertheless, it remains a great challenge to control the complex and predesigned shapes of artificial organic–inorganic hybrid materials at ambient conditions. Inspired by the plasticity of polymer‐induced liquid precursor phases that can penetrate and solidify in porous organic frameworks for biomineral formation, here a mineral plastic hydrogel is shown with ultrahigh silica content (≈95 wt%) that can be similarly hybridized into a porous delignified wood scaffold, and the resultant composite hydrogels can be manually made into arbitrary shapes. Subsequent air drying well preserves the designed shapes and produces fire‐retardant, ultrastrong, and tough structural organic–inorganic hybrids. The proposed mineral plastic hydrogel strategy opens an easy and eco‐friendly way for fabricating bioinspired structural materials that compromise both precise shape control and high mechanical strength.
Harnessing Heterogeneous Wrinkles in Metal/Polydimethylsiloxane Film System by Combination of Mechanical Loading and Heat Treatment
Authors: Lu Chenxi , Yu Senjiang , Li Huihua , Zhou Hong , Jiao Zhiwei , Li Lingwei 
Published: March 2020

AbstractSpontaneous wrinkled surfaces in nature usually possess unique physical and chemical properties. Inspired by nature and stimulated by practical application, artificial wrinkle patterns have received increasing interest recently. Here, the controllable heterogeneous wrinkles in metal films deposited on polydimethylsiloxane substrates by combination of mechanical loading and heat treatment is reported. It is found that the wrinkles are spontaneously localized at small strain condition due to the uneven distribution of wrinkle amplitudes on the film surface. The morphological features and underlying mechanisms of such wrinkles are investigated based on the strain theory. The friction property is found to be well controlled by the aspect ratio and orientation of the wrinkle patterns. Complex 2D wrinkle array is also achieved by applying heat treatment and mechanical compression in sequence. This study may broaden the knowledge of spontaneous heterogeneous wrinkles in film‐substrate system and provide a novel way to tailor various wrinkle patterns via independently tuning annealing temperature and mechanical strain.
Early season vigor in peanuts is dependent on leaf area responses to temperature
Authors: Virk Gurpreet , Pilon Cristiane , Snider John L. , Tubbs R. Scott 
Published: March 2020

AbstractWhole‐crop growth at early season in peanuts (Arachis hypogaea L.) can be influenced by genotype, management, and environmental conditions such as soil and air temperatures. To determine the effect of different planting conditions on peanut growth and vigor in the early season, modern peanut cultivars were planted in two growing seasons on 17 April, 10 May, and 5 June in 2017 and 25 April, 14 May, and 11 June in 2018 season, targeted to generate differences in temperature during early growth. Field measurements included emergence assessments and destructive harvest at 21 and 35 days after planting to quantify plant density, height, leaf area, and dry matter accumulation. Additionally, crop growth indices were calculated. Results showed that planting date and cultivar significantly affected plant growth parameters and derived growth indices. Planting in June resulted in greater growth parameters, crop growth rate, and leaf area index compared to April and May for both seasons. However, net assimilation rate was highest for May in 2017 and for June in 2018. Comparing cultivars, Georgia‐06G and TifNV‐high O/L were more vigorous than Georgia‐14N. Average soil and air temperatures were the highest with June planting and produced more vigorous seedling growth and greater crop growth rates than planting in April and May. Furthermore, our results suggest that the differences in the early season crop growth of modern peanut cultivars were more strongly and closely associated with leaf area development rather than specific leaf activity, that is, net assimilation rate of the canopy.
Kristalle in Minutenschnelle: Sofortige Mikrokristallisation verschiedenster Varianten der CYP102A1‐(P450BM3)‐Hämdomäne
Authors: Stanfield Joshua Kyle , Omura Keita , Matsumoto Ayaka , Kasai Chie , Sugimoto Hiroshi , Shiro Yoshitsugu , Watanabe Yoshihito , Shoji Osami 
Published: March 2020

AbstractDie Kristallisation der Hämdomäne von CYP102A1 (P450BM3) kann nach Modifizierung eine Herausforderung sein. Dennoch sind solche Kristallstrukturen unentbehrlich für die wirksame strukturbezogene Entwicklung von P450BM3 als Biokatalysator. Es wurde gezeigt, dass das Abietanditerpenderivat N‐Abietoyl‐l‐tryptophan (AbiATrp) ein hervorragender Kristallisationsbeschleuniger ist. Die Nutzung von Kristallen der P450BM3‐Hämdomäne mit AbiATrp als Impfkristalle ermöglichte die rasche Mikrokristallisation bei der naszierende Kristalle innerhalb von Sekunden nach Impfung erschienen. Hierdurch wurde eine Auswahl an Kristallen der P450BM3‐Hämdomäne erhalten, die bisher nicht kristallisierbare Täuschmoleküle, diverse künstliche Metalloporphyrine, welche verschiedenartige Liganden binden, sowie zusätzlich stark getaggte Hämdomänevarianten enthalten (37 zusätzliche Aminosäuren). Manche der Strukturen könnten als Modellverbindungen verschiedener Stadien des katalytischen Zyklus von P450BM3 genutzt werden.
Spatiotemporal Control of CRISPR/Cas9 Function in Cells and Zebrafish using Light‐Activated Guide RNA
Authors: Zhou Wenyuan , Brown Wes , Bardhan Anirban , Delaney Michael , Ilk Amber S. , Rauen Randy R. , Kahn Shoeb I. , Tsang Michael , Deiters Alexander 
Published: March 2020

AbstractWe developed a new method for the conditional regulation of CRISPR/Cas9 activity in mammalian cells and zebrafish embryos using photochemically activated, caged guide RNAs (gRNAs). Caged gRNAs are generated by substituting four nucleobases evenly distributed throughout the 5′‐protospacer region with caged nucleobases during synthesis. Caging confers complete suppression of gRNA:dsDNA‐target hybridization and rapid restoration of CRISPR/Cas9 function upon optical activation. This tool offers simplicity and complete programmability in design, high spatiotemporal specificity in cells and zebrafish embryos, excellent off‐to‐on switching, and stability by preserving the ability to form Cas9:gRNA ribonucleoprotein complexes. Caged gRNAs are novel tools for the conditional control of gene editing, thereby enabling the investigation of spatiotemporally complex physiological events by obtaining a better understanding of dynamic gene regulation.
An Fe2+‐ and α‐Ketoglutarate‐Dependent Halogenase Acts on Nucleotide Substrates
Authors: Zhao Chunhua , Yan Shan , Li Qin , Zhu Hucheng , Zhong Zhiyu , Ye Ying , Deng Zixin , Zhang Yonghui 
Published: March 2020

AbstractWhile halogenated nucleosides are used as common anticancer and antiviral drugs, naturally occurring halogenated nucleosides are rare. Adechlorin (ade) is a 2′‐chloro nucleoside natural product first identified from Actinomadura sp. ATCC 39365. However, the installation of chlorine in the ade biosynthetic pathway remains elusive. Reported herein is a Fe2+‐α‐ketoglutarate halogenase AdeV that can install a chlorine atom at the C2′ position of 2′‐deoxyadenosine monophosphate to afford 2′‐chloro‐2′‐deoxyadenosine monophosphate. Furthermore, 2′,3′‐dideoxyadenosine‐5′‐monophosphate and 2′‐deoxyinosine‐5′‐monophosphate can also be converted, albeit 20‐fold and 2‐fold, respectively, less efficiently relative to the conversion of 2′‐deoxyadenosine monophosphate. AdeV represents the first example of a Fe2+‐α‐ketoglutarate‐dependent halogenase that converts nucleotides into chlorinated analogues.
Silicon‐Free SuFEx Reactions of Sulfonimidoyl Fluorides: Scope, Enantioselectivity, and Mechanism
Authors: Liang Dong‐Dong , Streefkerk Dieuwertje E. , Jordaan Daan , Wagemakers Jorden , Baggerman Jacob , Zuilhof Han 
Published: March 2020

AbstractSuFEx reactions, in which an S−F moiety reacts with a silyl‐protected phenol, have been developed as powerful click reactions. In the current paper we open up the potential of SuFEx reactions as enantioselective reactions, analyze the role of Si and outline the mechanism of this reaction. As a result, fast, high‐yielding, “Si‐free” and enantiospecific SuFEx reactions of sulfonimidoyl fluorides have been developed, and their mechanism shown, by both experimental and theoretical methods, to yield chiral products.
Two‐Photon Absorption Enhancement by the Inclusion of a Tropone Ring in Distorted Nanographene Ribbons
Authors: Castro‐Fernández Silvia , Cruz Carlos M. , Mariz Inês F. A. , Márquez Irene R. , Jiménez Vicente G. , Palomino‐Ruiz Lucía , Cuerva Juan M. , Maçôas Ermelinda , Campaña Araceli G. 
Published: March 2020

AbstractA new family of distorted ribbon‐shaped nanographenes was designed, synthesized, and their optical and electrochemical properties were evaluated, pointing out an unprecedented correlation between their structural characteristics and the two‐photon absorption (TPA) responses and electrochemical band gaps. Three nanographene ribbons have been prepared: a seven‐membered‐ring‐containing nanographene presenting a tropone moiety at the edge, its full‐carbon analogue, and a purely hexagonal one. We have found that the TPA cross‐sections and the electrochemical band gaps of the seven‐membered‐ring‐containing compounds are higher and lower, respectively, than those of the fully hexagonal polycyclic aromatic hydrocarbon (PAH). Interestingly, the inclusion of additional curvature has a positive effect in terms of non‐linear optical properties of those ribbons.
Phenanthrene‐Fused‐Quinoxaline as a Key Building Block for Highly Efficient and Stable Sensitizers in Copper‐Electrolyte‐Based Dye‐Sensitized Solar Cells
Authors: Jiang Huiyun , Ren Yameng , Zhang Weiwei , Wu Yongzhen , Socie Etienne Christophe , Carlsen Brian Irving , Moser Jacques‐E. , Tian He , Zakeeruddin Shaik Mohammed , Zhu Wei‐Hong , Grätzel Michael 
Published: March 2020

AbstractDye‐sensitized solar cells (DSSCs) based on CuII/I bipyridyl or phenanthroline complexes as redox shuttles have achieved very high open‐circuit voltages (VOC, more than 1 V). However, their short‐circuit photocurrent density (JSC) has remained modest. Increasing the JSC is expected to extend the spectral response of sensitizers to the red or NIR region while maintaining efficient electron injection in the mesoscopic TiO2 film and fast regeneration by the CuI complex. Herein, we report two new D‐A‐π‐A‐featured sensitizers termed HY63 and HY64, which employ benzothiadiazole (BT) or phenanthrene‐fused‐quinoxaline (PFQ), respectively, as the auxiliary electron‐withdrawing acceptor moiety. Despite their very similar energy levels and absorption onsets, HY64‐based DSSCs outperform their HY63 counterparts, achieving a power conversion efficiency (PCE) of 12.5 %. PFQ is superior to BT in reducing charge recombination resulting in the near‐quantitative collection of photogenerated charge carriers.
Stimuli‐Responsive Particle‐Based Amphiphiles as Active Colloids Prepared by Anisotropic Click Chemistry
Authors: Lanz Cornelia , Schlötter Moritz , Klinkenberg Nele , Besirske Patricia , Polarz Sebastian 
Published: March 2020

AbstractAmphiphiles alter the energy of surfaces, but the extent of this feature is typically constant. Smart systems with amphiphilicity as a function of an external, physical trigger are desirable. As a trigger, the exposure to a magnetic field, in particular, is attractive because it is not shielded in water. Amphiphiles like surfactants are well known, but the magnetic response of molecules is typically weak. Vice‐versa, magnetic particles with strong response to magnetic triggers are fully established in nanoscience, but they are not amphiphilic. In this work colloids with Janus architecture and ultra‐small dimensions (25 nm) have been prepared by spatial control over the thiol‐yne click modification of organosilica‐magnetite core–shell nanoparticles. The amphiphilic properties of these anisotropically modified particles are proven. Finally, a pronounced and reversible change in interfacial stabilization results from the application of a weak (<1 T) magnetic field.
Designing Silicates as Deep‐UV Nonlinear Optical (NLO) Materials using Edge‐Sharing Tetrahedra
Authors: Wu Hongping , Zhang Bingbing , Yu Hongwei , Hu Zhanggui , Wang Jiyang , Wu Yicheng , Halasyamani P. Shiv 
Published: March 2020

AbstractDiscovering new deep‐ultraviolet (DUV) nonlinear optical (NLO) materials is currently a great challenge. The reported DUV NLO materials are almost exclusively borates or phosphates. Silicates—the largest constituent of the earth's crust—are excluded owing to their weak second harmonic generation (SHG) response. We report a silicate, Li2BaSiO4, with edge‐sharing LiO4–SiO4 tetrahedra that achieves the balance between a short UV absorption edge, below 190 nm, and a large SHG response, 2.8×KDP. The SHG intensity is the largest for silicates without second‐order Jahn–Teller cations, and exceeds that of non‐isomorphic Li2SrSiO4 by more than an order of magnitude. As such Li2BaSiO4 may be seen as a promising DUV‐UV NLO material. This research indicates that edge‐sharing tetrahedra is a new design parameter for discovering new DUV NLO materials.
Lead Mixed Oxyhalides Satisfying All Fundamental Requirements for High‐Performance Mid‐Infrared Nonlinear Optical Materials
Authors: Chen Xinglong , Jo Hongil , Ok Kang Min 
Published: March 2020

AbstractTo design high‐performance mid‐infrared (mid‐IR) nonlinear optical (NLO) materials, we have focused on the combination of a heavy metal lone pair cation, Pb2+ and mixed oxyhalides. A systematic investigation in PbO‐PbCl2‐PbBr2 system led us to discover the first examples of NLO lead mixed oxyhalides, namely, Pb13O6Cl4Br10, Pb13O6Cl7Br7, and Pb13O6Cl9Br5. All the reported materials have remarkably comprehensive properties including broad IR transparency (up to 14.0 μm), qualified second harmonic generation (SHG) responses (0.6–0.9×AgGaS2), wide band gaps (3.05–3.21 eV), and ease of crystal growth. Interestingly, a centimeter‐sized single crystal (2.9×1.3×0.5 cm3) of Pb13O6Cl9Br5 revealing a wide transparent range (0.384–14.0 μm) and high laser damage threshold (LDT) (14.6×AgGaS2) has been successfully grown in an open system. The study suggests that all the reported mixed oxyhalides are outstanding candidates for mid‐IR NLO materials.
Synthese von Galaktosyl‐Queuosin und Verteilung von hypermodifizierten Q‐Nukleosiden in Mausgeweben
Authors: Thumbs Peter , Ensfelder Timm T. , Hillmeier Markus , Wagner Mirko , Heiss Matthias , Scheel Constanze , Schön Alexander , Müller Markus , Michalakis Stylianos , Kellner Stefanie , Carell Thomas 
Published: March 2020

AbstractQueuosin (Q) ist ein hypermodifiziertes RNA‐Nukleosid, welches in tRNAHis, tRNAAsn, tRNATyr und tRNAAsp vorkommt. Es befindet sich an der Wobble‐Position der tRNA‐Antikodonschleife und kann sowohl mit U‐ als auch mit C‐Basen interagieren, welche sich an der entsprechenden Position der passenden mRNA‐Kodons befinden. In höheren Eukaryoten, einschließlich des Menschen, wird die Q‐Base in tRNATyr und tRNAAsp aus noch unbekannten Gründen durch einen Galaktose‐ bzw. Mannoserest weiter modifiziert. Die biologische Bedeutung dieser zusätzlichen Modifikation, sowie der Stoffwechselweg, über den die Zuckermodifikation mit der Bildung und dem Einbau von Q zusammenhängt, ist unbekannt. Wir berichten hier über die erste Totalsynthese des hypermodifizierten Nukleosids Galaktosyl‐Queuosin (galQ). Unter Verwendung des von uns synthetisierten Standards konnten die absoluten Mengen der Nukleoside der Q‐Familie nicht nur in sechs verschiedenen Organen von neugeborenen und ausgewachsenen Mäusen, sondern darüber hinaus auch in menschlichen zytosolischen tRNAs bestimmt werden. Unsere Synthese erlaubt nun eine detailliertere Analyse der biologischen Funktion der Q‐Nukleosid‐Familie.
Übergangsmetallfreie oxidative Kreuzkupplung von Tetraarylboraten zu Biarylen mit organischen Oxidationsmitteln
Authors: Gerleve Carolin , Studer Armido 
Published: March 2020

AbstractLeicht zugängliche Tetraarylborate reagieren in selektiven (Kreuz‐)Kupplungen durch Oxidation mit dem Bobbitt‐Salz zu symmetrischen und unsymmetrischen Biarylen. Das organische Oxoammoniumsalz kann entweder als stöchiometrisches Oxidationsmittel oder als Katalysator in Kombination mit in situ erzeugtem NO2 und molekularem Sauerstoff als terminalem Oxidans eingesetzt werden. Für ausgesuchte Fälle ist die oxidative Kupplung auch mit NO2/O2 ohne zusätzlichem Nitroxid‐basierten Co‐Katalysator möglich. Die übergangsmetallfreie katalytische oxidative Liganden‐Kreuzkupplung von Tetraarylboraten ist bisher beispiellos und die vorgestellte Methode ermöglicht den Zugang zu verschiedenen Biarylen und Heterobiarylen.
Dramatic Enhancement of Binding Affinities Between Foldamer‐Based Receptors and Anions by Intra‐Receptor π‐Stacking
Authors: Seo Sung Beom , Lee Seungwon , Jeon Hae‐Geun , Jeong Kyu‐Sung 
Published: March 2020

AbstractAs a synthetic model for intra‐protein interactions that reinforce binding affinities between proteins and ligands, the energetic interplay of binding and folding was investigated using foldamer‐based receptors capable of adopting helical structures. The receptors were designed to have identical hydrogen‐bonding sites for anion binding but different aryl appendages that simply provide additional π‐stacking within the helical backbones without direct interactions with the bound anions. In particular, the presence of electron‐deficient aryl appendages led to dramatic enhancements in the association constant between the receptor and chloride or nitrate ions, by up to three orders of magnitude. Extended stacking within the receptor contributes to the stabilization of the entire folding structure of complexes, thereby enhancing binding affinities.
Achieving Morphological Control over Lamellar Manganese Metal‐Organic Framework through Modulated Bi‐Phase Growth
Authors: Shen Yuxia , Shan Bohan , Mu Bin , Tongay Sefaattin 
Published: March 2020

AbstractA modulated bi‐phase synthesis towards large‐scale manganese 1,4‐benzenedicarboxylate (MnBDC) MOFs with a precise control over their morphology (bulk vs. layered) is presented. Metal precursors and organic ligands are separated to reduce the kinetic reaction rates for better control over the crystallization process. Based on scanning electron microscopy (SEM), X‐ray diffraction (XRD), energy‐dispersive X‐ray spectroscopy (EDS), and Raman spectroscopy studies, the continuous ligand supply along with the presence of pyridine capping agent are highly effective in promoting the layer‐by‐layer growth and achieving large crystal sizes. Once layered MnBDC is stabilized, topotactic intercalation chemistry was used to demonstrate the feasibility of bromine intercalation on these layered materials. Bromine intercalation is possible between the MOFs layers for the first time. Bromine intercalation causes colossal reduction in layered MnBDC band gap while it has no observable effect on bulk MOFs.