bluuebunny/crossref_metadata_2025 huggingface dataset:
Mini‐Metagenomics and Nucleotide Composition Aid the Identification and Host Association of Novel Bacteriophage Sequences
Authors: Deaton Jonathan , Yu Feiqiao Brian , Quake Stephen R.
Published: August 2019

A broad spectrum of metagenomic and single cell sequencing techniques have become popular for dissecting environmental microbial diversity, leading to the characterization of thousands of novel microbial lineages. In addition to recovering bacterial and archaeal genomes, metagenomic assembly can also produce genomes of viruses that infect microbial cells. Because of their diversity, lack of marker genes, and small genome size, identifying novel bacteriophage sequences from metagenomic data is often challenging, especially when the objective is to establish phage–host relationships. The present work describes a computational approach that uses supervised learning to classify metagenomic contigs as phage or non‐phage as well as assigning phage taxonomy based on tetranucleotide frequencies. Furthermore, the method assigns phage–host relationships using co‐occurrence statistics derived from a recently developed mini‐metagenomic experimental technique. This work evaluates method performance at identifying viral contigs and predicting taxonomic classification using publicly available references. Then, using two mini‐metagenomic datasets, over 100 novel phage contigs from hot spring samples of Yellowstone National Park are identified and assigned to putative microbial hosts. Results of this work demonstrate the value of combining viral sequence identification with mini‐metagenomic experimental methods to understand the microbial ecosystem.
Energy Transfer Induced by Dye Encapsulation in a Hybrid Nanoparticle‐Purple Membrane Reversible Assembly
Authors: de Q. Silveira Gleiciani , Chen Zhaowei , Barry Edward F. , Diroll Benjamin T. , Lee Byeongdu , Rajh Tijana , Rozhkova Elena A. , Laible Philip D. , Fry H. Christopher
Published: August 2019

The purple membrane (PM) isolated from the bacteria Halobacterium salinarum (H. salinarum) arranges the transmembrane proton pump bacteriorhodopsin (bR) in a 2D hexagonal crystalline lattice. Here, PM sheets containing native bR bend into tube‐like structures with open edges under acidic pH conditions. When decorated with gold nanoparticles (AuNPs), these same PM sheets yield a sealed tube assembly. Upon Rhodamine B (Rh B) sequestration inside the sealed tube, a dramatic decrease in Rh B fluorescence lifetime (τf) from 1.5 ns (unencapsulated) to 14 ps (encapsulated) is observed. The dramatic decrease in lifetime is attributed to energy transfer between AuNPs and Rh B. Subsequent release from the AuNP–PM capsules triggered by an increase in pH shows that 93% of Rh B is recovered (τ = 14 min) due to the capsules' unfolding. The hybrid AuNP–PM material highlights the utility of multicomponent ensembles (i.e., lipid bilayer, protein array, and NPs) by demonstrating that complex, multistimuli 3D responses can lead to multiplexed functions such as controlling energy transfer in the confined, encapsulated state and breaking the energy pair via molecular release in response to a change in pH.
Heterotypic Scaffold Design Orchestrates Primary Cell Organization and Phenotypes in Cocultured Small Diameter Vascular Grafts
Authors: Jungst Tomasz , Pennings Iris , Schmitz Michael , Rosenberg Antoine J. W. P. , Groll Jürgen , Gawlitta Debby
Published: August 2019

To facilitate true regeneration, a vascular graft should direct the evolution of a neovessel to obtain the function of a native vessel. For this, scaffolds have to permit the formation of an intraluminal endothelial cell monolayer, mimicking the tunica intima. In addition, when attempting to mimic a tunica media‐like outer layer, the stacking and orientation of vascular smooth muscle cells (vSMCs) should be recapitulated. An integral scaffold design that facilitates this has so far remained a challenge. A hybrid fabrication approach is introduced by combining solution electrospinning and melt electrowriting. This allows a tissue‐structure mimetic, hierarchically bilayered tubular scaffold, comprising an inner layer of randomly oriented dense fiber mesh and an outer layer of microfibers with controlled orientation. The scaffold supports the organization of a continuous luminal endothelial monolayer and oriented layers of vSM‐like cells in the media, thus facilitating control over specific and tissue‐mimetic cellular differentiation and support of the phenotypic morphology in the respective layers. Neither soluble factors nor a surface bioactivation of the scaffold is needed with this approach, demonstrating that heterotypic scaffold design can direct physiological tissue‐like cell organization and differentiation.
Microstructural and Interfacial Designs of Oxygen‐Permeable Membranes for Oxygen Separation and Reaction–Separation Coupling
Authors: Zhu Xuefeng , Yang Weishen
Published: August 2019

Mixed ionic–electronic conducting oxygen‐permeable membranes can rapidly separate oxygen from air with 100% selectivity and low energy consumption. Combining reaction and separation in an oxygen‐permeable membrane reactor significantly simplifies the technological scheme and reduces the process energy consumption. Recently, materials design and mechanism investigations have provided insight into the microstructural and interfacial effects. The microstructures of the membrane surfaces and bulk are closely related to the interfacial oxygen exchange kinetics and bulk diffusion kinetics. Therefore, the permeability and stability of oxygen‐permeable membranes with a single‐phase structure and a dual‐phase structure can be adjusted through their microstructural and interfacial designs. Here, recent advances in the development of oxygen permeation models that provide a deep understanding of the microstructural and interfacial effects, and strategies to simultaneously improve the permeability and stability through microstructural and interfacial design are discussed in detail. Then, based on the developed high‐performance membranes, highly effective membrane reactors for process intensification and new technology developments are highlighted. The new membrane reactors will trigger innovations in natural gas conversion, ammonia synthesis, and hydrogen‐related clean energy technologies. Future opportunities and challenges in the development of oxygen‐permeable membranes for oxygen separation and reaction–separation coupling are also explored.
Ceria Nanoparticles Meet Hepatic Ischemia‐Reperfusion Injury: The Perfect Imperfection
Authors: Ni Dalong , Wei Hao , Chen Weiyu , Bao Qunqun , Rosenkrans Zachary T. , Barnhart Todd E. , Ferreira Carolina A. , Wang Yanpu , Yao Heliang , Sun Tuanwei , Jiang Dawei , Li Shiyong , Cao Tianye , Liu Zhaofei , Engle Jonathan W. , Hu Ping , Lan Xiaoli , Cai Weibo
Published: August 2019

The mononuclear phagocyte system (MPS, e.g., liver, spleen) is often treated as a “blackbox” by nanoresearchers in translating nanomedicines. Often, most of the injected nanomaterials are sequestered by the MPS, preventing their delivery to the desired disease areas. Here, this imperfection is exploited by applying nano‐antioxidants with preferential liver uptake to directly prevent hepatic ischemia‐reperfusion injury (IRI), which is a reactive oxygen species (ROS)‐related disease. Ceria nanoparticles (NPs) are selected as a representative nano‐antioxidant and the detailed mechanism of preventing IRI is investigated. It is found that ceria NPs effectively alleviate the clinical symptoms of hepatic IRI by scavenging ROS, inhibiting activation of Kupffer cells and monocyte/macrophage cells. The released pro‐inflammatory cytokines are then significantly reduced and the recruitment and infiltration of neutrophils are minimized, which suppress subsequent inflammatory reaction involved in the liver. The protective effect of nano‐antioxidants against hepatic IRI in living animals and the revealed mechanism herein suggests their future use for the treatment of hepatic IRI in the clinic.
Efficient Synthesis of 12‐Oxochenodeoxycholic Acid Using a 12α‐Hydroxysteroid Dehydrogenase from Rhodococcus ruber
Authors: Shi Shou‐Cheng , You Zhi‐Neng , Zhou Ke , Chen Qi , Pan Jiang , Qian Xiao‐Long , Xu Jian‐He , Li Chun‐Xiu
Published: August 2019

12α‐Hydroxysteroid dehydrogenase (12α‐HSDH) has the potential to convert cheap and readily available cholic acid (CA) to 12‐oxochenodeoxycholic acid (12‐oxo‐CDCA), a key precursor for chemoenzymatic synthesis of the therapeutic bile acid ursodeoxycholic acid (UDCA). In this work, a native nicotinamide adenine dinucleotide (NAD+)‐dependent 12α‐hydroxysteroid dehydrogenase (Rr12α‐HSDH) from Rhodococcus ruber was identified using a structure‐guided genome mining (SSGM) approach, which is based on the structure of cofactor pocket and the conserved nicotinamide cofactor binding motif alignment. Rr12α‐HSDH was heterologously overexpressed in Escherichia coli BL21 (DE3), purified and characterized. The purified Rr12α‐HSDH showed a high oxidative activity of 290 U mg−1protein toward CA, with a catalytic efficiency (kcat/KM) of 5.10×103 mM−1 s−1. In a preparative biotransformation (100 mL), CA (200 mM, 80 g L−1) was efficiently converted to 12‐oxo‐CDCA in 1 h, with a 85% isolated yield and a space‐time yield (STY) of up to 1632 g L−1 d−1. Furthermore, Rr12α‐HSDH was shown to be able to catalyze the oxidation of other 12α‐hydroxysteroids at high substrate loads (up to 200 mM), giving the corresponding 12‐oxo‐hydroxysteroids in 71%–85% yields, indicating the great potential of Rr12α‐HSDH as a promising biocatalyst for the synthesis of various therapeutic bile acids.

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Spray‐flame synthesis of La(Fe, Co)O3 nano‐perovskites from metal nitrates
Authors: Angel Steven , Neises Julian , Dreyer Maik , Friedel Ortega Klaus , Behrens Malte , Wang Yuan , Arandiyan Hamidreza , Schulz Christof , Wiggers Hartmut
Published: August 2019

Nano‐sized perovskites were synthesized in a spray flame from nitrate precursors dissolved in ethanol and in ethanol/2‐ethylhexanoic acid (2‐EHA) mixtures. Experiments with ethanol led to a broad particle‐size distribution and to the formation of undesired phases such as La2CoO4, La2O3, and Co3O4. The addition of 2‐EHA can initiate micro explosions of the burning droplets and has been systematically investigated toward the formation of single‐phase, high‐surface‐area LaCoO3 and LaFeO3 with a narrow size distribution. To investigate the effect of 2‐EHA, temperature‐dependent changes of the chemical composition of the precursor solutions were analyzed with ATR‐FTIR between 23 and 70°C. In all cases, the formation of esters was identified while in the solutions containing iron, additional formation of carboxylates was observed. The synthesized materials were characterized by BET SSA, XRD, SAED and EDX‐TEM and their catalytic activity was analyzed, reaching 50% CO conversion at temperatures below 160 and 300°C for LaCoO3 and LaFeO3, respectively.
Liquid Metal Gallium Micromachines Speed Up in Confining Channels
Authors: Wang Daolin , Lin Zhihua , Zhou Chang , Gao Changyong , He Qiang
Published: August 2019

One of the great challenges in the field of tiny machines is the capability of engineering liquid metal micromachines to autonomously move within confining channels to perform various complex tasks. Herein, liquid metal gallium micromachines that significantly increase their velocity in confining channels with adaptive deformation under exposure to an electric field are presented. The liquid metal gallium micromachines move toward the negative electrode under the propulsion of hydrogen bubbles, which is obviously different from the previous report that liquid metal gallium alloy (i.e., Galinstan) micromachines move to the positive electrode, owing to the surface tension gradient. More importantly, the liquid metal gallium micromachine can adaptively deform and accelerate in confined channels. The velocity of liquid metal gallium micromachines increases with the decrease in the width of channels. It is found that the speed‐up motion of liquid metal gallium micromachines is caused by the enhanced electro‐osmosis effect in confining channels. The findings not only help understand the role of the confinement effect on the motion of liquid metal micromachines but also provide a novel strategy to manipulate the motion velocity of liquid metal micromachines for specific applications.
Recognition and management of adults with Turner syndrome: From the transition of adolescence through the senior years
Authors: Lin Angela E. , Prakash Siddharth K. , Andersen Niels H. , Viuff Mette H. , Levitsky Lynne L. , Rivera‐Davila Michelle , Crenshaw Melissa L. , Hansen Lars , Colvin Mary K. , Hayes Frances J. , Lilly Evelyn , Snyder Emma A. , Nader‐Eftekhari Shahla , Aldrich Melissa B. , Bhatt Ami B. , Prager Laura M. , Arenivas Ana , Skakkebaek Anne , Steeves Marcie A. , Kreher Jeffrey B. , Gravholt Claus H.
Published: August 2019

Turner syndrome is recognized now as a syndrome familiar not only to pediatricians and pediatric specialists, medical geneticists, adult endocrinologists, and cardiologists, but also increasingly to primary care providers, internal medicine specialists, obstetricians, and reproductive medicine specialists. In addition, the care of women with Turner syndrome may involve social services, and various educational and neuropsychologic therapies. This article focuses on the recognition and management of Turner syndrome from adolescents in transition, through adulthood, and into another transition as older women. It can be viewed as an interpretation of recent international guidelines, complementary to those recommendations, and in some instances, an update. An attempt was made to provide an international perspective. Finally, the women and families who live with Turner syndrome and who inspired several sections, are themselves part of the broad readership that may benefit from this review.
Tight Xenon Confinement in a Crystalline Sandwich‐like Hydrogen‐Bonded Dimeric Capsule of a Cyclic Peptide
Authors: Pizzi Andrea , Ozores Haxel Lionel , Calvelo Martín , García‐Fandiño Rebeca , Amorín Manuel , Demitri Nicola , Terraneo Giancarlo , Bracco Silvia , Comotti Angiolina , Sozzani Piero , Bezuidenhout Charl X. , Metrangolo Pierangelo , Granja Juan R.
Published: August 2019

A cyclic hexapeptide with three pyridyl moieties connected to its backbone forms a hydrogen‐bonded dimer, which tightly encapsulates a single xenon atom, like a pearl in its shell. The dimer imprints its shape and symmetry to the captured xenon atom, as demonstrated by 129Xe NMR spectroscopy, single‐crystal X‐ray diffraction, and computational studies. The dimers self‐assemble hierarchically into tubular structures to form a porous supramolecular architecture, whose cavities are filled by small molecules and gases.
Self‐Stabilized Amorphous Organic Materials with Room‐Temperature Phosphorescence
Authors: Xu Wei , Yu Yaguo , Ji Xiaonan , Zhao Huarui , Chen Jinming , Fu Yanyan , Cao Huimin , He Qingguo , Cheng Jiangong
Published: August 2019

The stability of pure organic room‐temperature phosphorescent (RTP) materials in air has been a research hotspot in recent years. Without crystallization or encapsulation, a new strategy was proposed to obtain self‐stabilized organic RTP materials, based on a complete ionization of a photo‐induced charge separation system. The ionization of aromatic phenol 4‐carbazolyl salicylaldehyde (CSA) formed a stable H‐bonding anion–cation radical structure and led to the completely amorphous CSA‐I film. Phosphorescent lifetimes as long as 0.14 s at room temperature and with direct exposure to air were observed. The emission intensity was also increased by 21.5‐fold. Such an amorphous RTP material reconciled the contradiction between phosphorescence stability and vapor permeability and has been successfully utilized for peroxide vapor detection.
Eine ungewöhnliche Gerüstumlagerung in der Biosynthese des Sesquiterpens Trichobrasilenol aus Trichoderma
Authors: Murai Keiichi , Lauterbach Lukas , Teramoto Kazuya , Quan Zhiyang , Barra Lena , Yamamoto Tsuyoshi , Nonaka Kenichi , Shiomi Kazuro , Nishiyama Makoto , Kuzuyama Tomohisa , Dickschat Jeroen S.
Published: August 2019

Die Gerüste mancher Klassen von Terpenen sind ungewöhnlich, da sie eine größere Anzahl an Me‐Gruppen (oder biosynthetische Äquivalente wie olefinische Methylengruppen, Hydroxymethylgruppen, Aldehyde oder Carbonsäuren und ihre Derivate) aufweisen als durch ihren Oligoprenyldiphosphatvorläufer zur Verfügung gestellt werden. Dies resultiert manchmal aus einer oxidativen Ringöffnungsreaktion an einem von einer Terpencyclase gebildeten Molekül mit regulärer Anzahl von Me‐Gruppenäquivalenten, wie es für die Picrotoxan‐Sesquiterpene beobachtet wird. In dieser Studie wird eine Sesquiterpencyclase aus Trichoderma beschrieben, die Farnesyldiphosphat (FPP) direkt unter Beteiligung einer bemerkenswerten Gerüstumlagerung in Trichobrasilenol, ein neues Brasilan‐Sesquiterpen mit einem verglichen mit FPP zusätzlichen Me‐Gruppenäquivalent, umsetzen kann. Eine mechanistische Hypothese für die Bildung des Brasilan‐Skeletts wird durch extensive Isotopenmarkierungsstudien gestützt.
Tetravinylallene
Authors: Elgindy Cecile , Ward Jas S. , Sherburn Michael S.
Published: August 2019

The first chemical synthesis of tetravinylallene (3,5‐divinylhepta‐1,3,4,6‐tetraene) is reported. The final, key step of the synthesis involves a palladium‐catalyzed, Negishi‐type cross‐coupling involving 1,5‐transposition of a penta‐2‐en‐4‐yn‐1‐ol methanesulfonate. The unprecedented fundamental hydrocarbon is sufficiently stable to be purified by flash chromatography. A similar synthetic pathway grants access to the first substituted tetravinylallenes, which provide insights into the influence of substitution upon stability and reactivity. Tetravinylallenes are shown to break new ground in swift structural complexity creation, with three novel sequences reported.
Aggregation‐Induced Emission Gold Clustoluminogens for Enhanced Low‐Dose X‐ray‐Induced Photodynamic Therapy
Authors: Sun Wenjing , Luo Li , Feng Yushuo , Cai Yuting , Zhuang Yixi , Xie Rong‐Jun , Chen Xiaoyuan , Chen Hongmin
Published: August 2019

The use of gold nanoparticles as radiosensitizers is an effective way to boost the killing efficacy of radiotherapy while drastically limiting the received dose and reducing the possible damage to normal tissues. Herein, we designed aggregation‐induced emission gold clustoluminogens (AIE‐Au) to achieve efficient low‐dose X‐ray‐induced photodynamic therapy (X‐PDT) with negligible side effects. The aggregates of glutathione‐protected gold clusters (GCs) assembled through a cationic polymer enhanced the X‐ray‐excited luminescence by 5.2‐fold. Under low‐dose X‐ray irradiation, AIE‐Au strongly absorbed X‐rays and efficiently generated hydroxyl radicals, which enhanced the radiotherapy effect. Additionally, X‐ray‐induced luminescence excited the conjugated photosensitizers, resulting in a PDT effect. The in vitro and in vivo experiments demonstrated that AIE‐Au effectively triggered the generation of reactive oxygen species with an order‐of‐magnitude reduction in the X‐ray dose, enabling highly effective cancer treatment.
Dianionic Mononuclear Cyclo‐P4 Complexes of Zero‐Valent Molybdenum: Coordination of the Cyclo‐P4 Dianion in the Absence of Intramolecular Charge Transfer
Authors: Mandla Kyle A. , Neville Michael L. , Moore Curtis E. , Rheingold Arnold L. , Figueroa Joshua S.
Published: August 2019

Relative to other cyclic poly‐phosphorus species (that is, cyclo‐Pn), the planar cyclo‐P4 group is unique in its requirement of two additional electrons to achieve aromaticity. These electrons are supplied from one or more metal centers. However, the degree of charge transfer is dependent on the nature of the metal fragment. Unique examples of dianionic mononuclear η4‐P4 complexes are presented that can be viewed as the simple coordination of the [cyclo‐P4]2− dianion to a neutral metal fragment. Treatment of the neutral, molybdenum cyclo‐P4 complexes Mo(η4‐P4)I2(CO)(CNArDipp2)2 and Mo(η4‐P4)(CO)2(CNArDipp2)2 with KC8 produces the dianionic, three‐legged piano stool complexes, [Mo(η4‐P4)(CO)(CNArDipp2)2]2− and [Mo(η4‐P4)(CO)2(CNArDipp2)]2−, respectively. Structural, spectroscopic, and computational studies reveal a similarity to the classic η6‐benzene complex (η6‐C6H6)Mo(CO)3 regarding the metal‐center valence state and electronic population of the planar‐cyclic ligand π system.
Observing the Reversible Single Molecule Electrochemistry of Alexa Fluor 647 Dyes by Total Internal Reflection Fluorescence Microscopy
Authors: Fan Sanjun , Webb James E. A. , Yang Ying , Nieves Daniel J. , Gonçales Vinicius R. , Tran Jason , Hilzenrat Geva , Kahram Mohaddeseh , Tilley Richard D. , Gaus Katharina , Gooding J. Justin
Published: August 2019

Alexa Fluor 647 is a widely used fluorescent probe for cell bioimaging and super‐resolution microscopy. Herein, the reversible fluorescence switching of Alexa Fluor 647 conjugated to bovine serum albumin (BSA) and adsorbed onto indium tin oxide (ITO) electrodes under electrochemical potential control at the level of single protein molecules is reported. The modulation of the fluorescence as a function of potential was observed using total internal reflectance fluorescence (TIRF) microscopy. The fluorescence intensity of the Alexa Fluor 647 decreased, or reached background levels, at reducing potentials but returned to normal levels at oxidizing potentials. These electrochemically induced changes in fluorescence were sensitive to pH despite that BSA‐Alexa Fluor 647 fluorescence without applied potential is insensitive to pH between values of 4–10. The observed pH dependence indicated the involvement of electron and proton transfer in the fluorescence switching mechanism.
Copper‐Rich Thermoelectric Sulfides: Size‐Mismatch Effect and Chemical Disorder in the [TS4]Cu6 Complexes of Cu26T2Ge6S32 (T=Cr, Mo, W) Colusites
Authors: Pavan Kumar Ventrapati , Guélou Gabin , Lemoine Pierric , Raveau Bernard , Supka Andrew R. , Al Rahal Al Orabi Rabih , Fornari Marco , Suekuni Koichiro , Guilmeau Emmanuel
Published: August 2019

Herein, we investigate the Mo and W substitution for Cr in synthetic colusite, Cu26Cr2Ge6S32. Primarily, we elucidate the origin of extremely low electrical resistivity which does not compromise the Seebeck coefficient and leads to outstanding power factors of 1.94 mW m−1 K−2 at 700 K in Cu26Cr2Ge6S32. We demonstrate that the abnormally long iono‐covalent T–S bonds competing with short metallic Cu–T interactions govern the electronic transport properties of the conductive “Cu26S32” framework. We address the key role of the cationic size‐mismatch at the core of the mixed tetrahedral–octahedral complex over the transport properties. Two essential effects are identified: 1) only the tetrahedra that are directly bonded to the [TS4]Cu6 complex are significantly distorted upon substitution and 2) the major contribution to the disorder is localized at the central position of the mixed tetrahedral–octahedral complex, and is maximized for x=1, i.e. for the highest cationic size‐variance, σ2.
Scaled‐Up Synthesis of Amorphous NiFeMo Oxides and Their Rapid Surface Reconstruction for Superior Oxygen Evolution Catalysis
Authors: Duan Yu , Yu Zi‐You , Hu Shao‐Jin , Zheng Xu‐Sheng , Zhang Chu‐Tian , Ding Hong‐He , Hu Bi‐Cheng , Fu Qi‐Qi , Yu Zhi‐Long , Zheng Xiao , Zhu Jun‐Fa , Gao Min‐Rui , Yu Shu‐Hong
Published: August 2019

The anode oxygen evolution reaction (OER) is known to largely limit the efficiency of electrolyzers owing to its sluggish kinetics. While crystalline metal oxides are promising as OER catalysts, their amorphous phases also show high activities. Efforts to produce amorphous metal oxides have progressed slowly, and how an amorphous structure benefits the catalytic performances remains elusive. Now the first scalable synthesis of amorphous NiFeMo oxide (up to 515 g in one batch) is presented with homogeneous elemental distribution via a facile supersaturated co‐precipitation method. In contrast to its crystalline counterpart, amorphous NiFeMo oxide undergoes a faster surface self‐reconstruction process during OER, forming a metal oxy(hydroxide) active layer with rich oxygen vacancies, leading to superior OER activity (280 mV overpotential at 10 mA cm−2 in 0.1 m KOH). This opens up the potential of fast, facile, and scale‐up production of amorphous metal oxides for high‐performance OER catalysts.
DGEBA‐polyaminoamide as effective anti‐corrosive material for 15CDV6 steel in NaCl medium: Computational and experimental studies
Authors: Dagdag Omar , Berisha Avni , Safi Zaki , Hamed Othman , Jodeh Shehdeh , Verma Chandrabhan , Ebenso E. E. , El Harfi Ahmed
Published: August 2019

The present study is focusing on evaluating theoretically and experimentally stability and type of interactions between the epoxy resin bisphenol A diglycidyl ether (DGEBA)‐polyaminoamide anticorrosive coating and high strength low alloy steel surface 15CDV6. The coated steel samples were subjected to a harsh environment of an electrolyte solution of 3 wt % NaCl to simulate the corrosive marine environment. The performance of the epoxy coating was investigated using electrochemical impedance spectroscopy (EIS). The EIS results revealed the occurrence of some deterioration in the film after subjecting it to a harsh environment for 4392 h, because the impedance of the coating dropped by about 1.4 kΩ.cm2. Surface morphological study of metallic specimens before and after exposing to the simulated marine environment (3 wt % NaCl) was carried out using scanning electron microscopy, energy dispersive spectroscopy (EDS), and optical microscope (OM) methods. The interactions between DGEBA‐polyaminoamide and the metallic surface were further carried out using computation modeling such as density functional theory (DFT)‐based quantum chemical calculations, Monte Carlo (MC), and molecular dynamics (MD) simulations. Results showed that DGEBA‐polyaminoamide possesses a strong tendency to adhere and inhibits the corrosive dissolution of 15CDV6 steel surface in the stimulated marine environment. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48402.
Preparation, characterization, and antibacterial activity of cationic nanopolystyrenes
Authors: Wen Qing , Xu Lijuan , Xiao Xiansen , Wang Zhenghui
Published: August 2019

Cationic nanopolystyrenes (CNPSs) were prepared by the polymerization of styrene with a cationic polymerizable emulsifier, N‐(2‐(methacryloyloxy)ethyl)‐N,N‐dimethyltetradecane‐1‐ammonium bromide (MDTB), in the presence of 2,2′‐azobis(2‐methylpropionamidine) dihydrochloride (APPH). The polymerization kinetics was investigated through monomer conversion versus polymerization time. 1H NMR spectra and FTIR spectra were used to confirm the structures of MDTB and nanopolymers. The particle size, ζ‐potential, molecular weight, and thermal stability were also investigated by Zetasizer, gel permeation chromatography, and thermogravimetric analysis, respectively. The antibacterial activities of the obtained products were evaluated by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against Staphylococcus aureus ATCC 29913 (S. aureus, a Gram‐positive bacterium) and Escherichia coli ATCC 25922 (E. coli, a Gram‐negative bacterium). The results indicated that the polymerization has the characteristics of microemulsion polymerization, all nanopolystyrenes are cationic and can be stored in the form of a microemulsion in aqueous phase, CNPSs present stable chemical structure at 190 °C, and their MIC and MBC reach 0.0625 and 0.125 mg mL−1 for E. coli, 0.0325 and 0.0625 mg mL−1 for S. aureus, respectively. Therefore, CNPSs are a promising new type of polymer antimicrobial agent, which can be used in the development of antimicrobial polymer materials and their products. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48405.
Geochemical sourcing of volcanic materials imported into Teti'aroa Atoll shows multiple long‐distance interactions in the Windward Society Islands, French Polynesia
Authors: HERMANN AYMERIC , MOLLE GUILLAUME , MAURY RENÉ , LIORZOU CÉLINE , MCALISTER ANDREW
Published: August 2019

Teti'aroa, located 28 nautical miles (52 km) north of Tahiti, lies at the periphery of the Windward Society islands. At the end of the eighteenth century, this atoll was presumably controlled by the chiefdom of Porionu'u, which included the districts of Pare and Arue on the north coast of Tahiti. This situation is confirmed by a number of ethnohistorical accounts and oral traditions describing an intense traffic of basic resources between the atoll and Tahiti island as well as the specific function of Teti'aroa for Tahitian social elites visiting the atoll for ceremonial or recreational purposes. However, the prehistory of the atoll remains largely unknown and the time‐depth of dominance by Tahitian elites on the atoll is unclear. In this paper, we investigate potential inter‐island relationships between Teti'aroa and other islands in the archipelago and beyond. We present geochemical analyses (energy dispersive X‐ray fluorescence and inductively coupled plasma‐atomic emission spectrometry) of stone tools and elements of ceremonial architecture (marae), which were necessarily imported given the complete subsidence of the volcanic substratum of the island. Our results confirm the regional origin of a majority of artefacts, but also indicate several later long‐distance relationships maintained by Tahitian chiefs.
Phenylene‐bridged Porphyrinmeso‐Oxy Radical Dimers
Authors: Yamamoto Takayuki , Kato Kenichi , Shimizu Daiki , Tanaka Takayuki , Osuka Atsuhiro
Published: August 2019

Stablemeta‐ andpara‐phenylene bridged porphyrinmeso‐oxy radical dimers and their NiIIand ZnIIcomplexes were synthesized. All the dimers exhibited optical and electrochemical properties similar to the corresponding porphyrinmeso‐oxy radical monomers, indicating small electronic interaction between the two spins. Intramolecular spin‐spin interaction through the π‐spacer was determined to beJ/kB=−15.9 K form‐phenylene bridged ZnIIporphyrin dimer. The observed weak antiferromagnetic interaction has been attributed to less effective conjugation between the porphyrin radical and linking π‐spacer due to large dihedral angle. In the case of ZnIIcomplexes, bothpara‐ andmeta‐phenylene bridged dimers formed 1D‐chain in solutions and in the solid states through Zn‐O coordination.
Enhancing the Rate Capability of Niobium Oxide Electrode through Rare‐Earth Doping Engineering
Authors: Yin Dandan , Zhao Hongyang , Li Na , Si Rui , Sun Xiaolei , Li Xinghua , Du Yaping
Published: August 2019

Niobium oxide is considered one of the most promising electrode materials for ultrafast electrochemical energy storage devices with high energy density. In this work, we first found that trace amounts (<1 %) of Yb3+ doping remarkably enhanced the rate capability of T−Nb2O5, which was further proved to be because of the formation of a thin layer of amorphous YbNbOx. The capacity of YbNbOx‐coated Nb2O5 reached 124 mAh g−1 at 20 C, which is the highest value reported among pristine Nb2O5 electrodes. Besides, we found that doping with other rare‐earth elements such as Nd3+, Sm3+, and Gd3+ can also improve the rate capability of T−Nb2O5. It can be concluded that rare‐earth doping can be an effective and robust method to enhance the intrinsic rate performance of electrode materials without complicated modifications.
Parental choice of childcare in England: Choosing in phases and the split market
Authors: Chen Huan , Bradbury Alice
Published: August 2019

This article explores how parents choose childcare settings for their pre‐school children within a context of complex policy on eligibility for free provision and a developing market. Using data from interviews with 17 mainly middle‐class parents in England, we explore in detail how parents go about choosing a childcare setting and the different phases of this process. This adds further nuance to the existing literature on choosing practices and the dysfunction and inequalities of a neoliberal childcare market, and also updates the discussion to include recent policy developments such as the provision of ‘30 hours free childcare’ for 3 and 4‐year‐olds. We conclude that parental choosing involves a series of decisions in two or three phases, which start from practical considerations, followed by quality comparison and then back to practical constraints if a decision has not been made. The options open to parents are split between not only those able to accommodate shorter ‘free’ provision and those that require longer periods of childcare to work, but also between those with children under three and above. Contrary to previous findings in this area, this split may work to the disadvantage of some middle‐class families, whose children attend lower‐quality settings as a result.
MicroRNAs play an essential role in autophagy regulation in various disease phenotypes
Authors: Zhao Yunyi , Wang Ze , Zhang Wenhui , Zhang Linbo
Published: August 2019

Autophagy is a highly conserved catabolic process and fundamental biological process in eukaryotic cells. It recycles intracellular components to provide nutrients during starvation and maintains quality control of organelles and proteins. In addition, autophagy is a well‐organized homeostatic cellular process that is responsible for the removal of damaged organelles and intracellular pathogens. Moreover, it also modulates the innate and adaptive immune systems. Micro ribonucleic acids (microRNAs) are a mature class of post‐transcriptional modulators that are widely expressed in tissues and organs. And, it can suppress gene expression by targeting messenger RNAs for translational repression or, at a lesser extent, degradation. Research indicates that microRNAs regulate autophagy through different pathways, playing an essential role in the treatment of various diseases. It is an important regulator of fundamental cellular processes such as proliferation, autophagy, and cell apoptosis. In this review article, we first review the current knowledge of autophagy and the function of microRNAs. Then, we summarize the mechanism of autophagy and the signaling pathways related to autophagy by citing at least the main proteins involved in the different phases of the process. Second, we introduce other members of RNA and report some examples in various pathologies. Finally, we review the current literature regarding microRNA‐based therapies for cancer, atherosclerosis, cardiac disease, tuberculosis, and viral diseases. MicroRNAs can cause autophagy upregulation or downregulation by targeting genes or affecting autophagy‐related signaling pathways. Therefore, the microRNAs have a huge potential in autophagy regulation, and it is the function as diagnostic and prognostic markers.
Enhancement of Mechanical Stability and Ionic Conductivity of Chitosan‐based Solid Polymer Electrolytes Using Silver Nanowires as Fillers
Authors: Kim Jae Seok , Lim Jong Kuk , Park Jin Seong
Published: August 2019

With the emergence of wearable devices and internet of things, it is expected that small flat, and flexible electrochemical devices will be required for these applications. One of the prerequisites for these devices to be applied to such fields is the development of solid polymer electrolytes with high ionic conductivity. Because most solid polymer electrolytes have low ionic conductivity, small organic molecules have been used as plasticizers to increase their ionic conductivity. Since these plasticizers can increase amorphous regions that play the role of ion channels in polymer, their ionic conductivity increases; however, their mechanical stability decreases inversely. Conventionally, to overcome this drawback, inert nanoparticles are added into solid polymer electrolytes as fillers. Herein, we show that 1‐dimensional silver nanowires can increase the mechanical stability of chitosan‐based solid polymer electrolytes as well as their ionic conductivity more than nanospheres can, and discuss a plausible mechanism for such an enhancement.
Quantitative ultra‐high‐performance liquid chromatography–tandem mass spectrometry for determination of dexmedetomidine in pediatric plasma samples: Correlation with genetic polymorphisms
Authors: Guan Yanping , Li Bilian , Wei Wei , Wang Siyi , Yuen Vivian‐min , Liu Yao , Ao Zheng , Zhou Shan , Tian Hang , Huang Min , Song Xingrong , Zhong Guoping
Published: August 2019

Dexmedetomidine is an important sedative agent administered as premedication to achieve procedural sedation in children. To describe the correlation between the genetic state and the concentration of dexmedetomidine, it is necessary to develop a specific, time‐saving and economical method for detection of dexmedetomidine in plasma samples. In this work, an ultra‐high‐performance liquid chromatography (UHPLC)–tandem mass spectrometry method has been established and validated for detection of dexmedetomidine in plasma from pediatric population. After a simple liquid–liquid extraction with an organic solution, the analytes were separated on an ACQUITY BEH C18 column (2.1 mm × 50 mm, 1.7 μm particle size) by gradient elution with the mobile phase of acetonitrile and 1‰ aqueous formic acid (flow rate 0.3 mL min−1). Mass spectrometry measurements were performed under the positive selected reaction monitoring and the mass transitions monitored were m/z 201.3 → 95.1, 204.2 → 98.0 for dexmedetomidine and deuterated medetomidine (internal standard), respectively. Validation of the method based on China Food and Drug Administration guidelines showed acceptable selectivity. The UHPLC method employed a stable isotope‐labeled internal standard, showed good specificity and was successfully used to detect dexmedetomidine in plasma samples from 260 pediatric patients. A subsequent application of this method to a pharmacogenetic study was also described. Importantly, this is the first study to report the correlation between CYP2A6 rs835309 activity and concentration of dexmedetomidine.
Computer simulations to approach surface tension by means of a simple mesoscopic mechanical model
Authors: Battaglia Onofrio R. , Agliolo Gallitto Aurelio , Fazio Claudio
Published: August 2019

A small insect can stand or walk on water surface, drops of mercury do not spread on a solid surface, and a meniscus is formed at the free surface of a liquid contained in a thin vessel. These phenomena can be seen as macroscopic manifestations of molecular interactions and can be explained macroscopically in terms of surface tension. In this study, we deal with an approach to surface tension from a mechanical point of view, presenting a simple mesoscopic mechanical model of surface tension and the results of its implementation in numerical fluid dynamics simulations. Particularly, phenomena like droplet formation without gravity and with gravity when it can drop from a narrow hole like a trickling tap, the formation of a meniscus at the free surface of a liquid contained in a vessel, the behavior of a small piece of solid on a liquid surface, and a sessile droplet are studied. Student and teachers can study the behavior of a liquid due to the surface tension by using the numeric simulations as a “tool” for analyzing several different situations.
An ontology‐based framework of assessment analytics for massive learning
Authors: Nouira Azer , Cheniti‐Belcadhi Lilia , Braham Rafik
Published: August 2019

Analyzing learning traces is presently highly required in e‐learning environment. Several communities have been developed to address this need, such as those of Learning Analytics and Educational Data Mining. The main step of performing a learning analytics process is the educational data collection.

Actually, learning environments such as Massive Open Online Course (MOOC) generate a big amount of educational data. They can be divided into assessment data, collaboration data, communication data, and so on. When we focus on assessment, we can launch a new source of data that can be analyzed and hence contribute to the improvement of learning analytics field.

In this paper, we explore, investigate and compare the set of learning analytics models in the literature. Then, we study them from assessment point of view. The only current learning analytics model which can support tracking and modeling assessment data is the xAPI data model. For this reason, we study and investigate the xAPI specification from assessment point of view. Based on identified weaknesses of xAPI specification, we propose an enhancement of its data model. This is to support the assessment analytics effectively. We present an ontological model for assessment analytics inspired from the xAPI specification. To validate our approach, we focus on massive learning traces extracted from a real MOOC. Thus, we define and execute the set of proposed steps of preprocessing stage that extracts assessment data from whole learning data. Furthermore, we develop a java semantic web application to convert assessment data extracted to OWL file according to our proposed ontological model for assessment analytics.
Perceived discrimination is associated with poorer health and well‐being outcomes among Pacific peoples in New Zealand
Authors: Kapeli Sarah A. , Manuela Sam , Sibley Chris G.
Published: August 2019

Our study investigated the association between perceived discrimination and outcomes related to health and well‐being for Pacific adults in New Zealand. We examined personal and group discrimination from the 2013 wave of the New Zealand Attitudes and Values Study (n = 429 women and 196 men). Personal discrimination was associated with poorer health and well‐being outcomes (higher psychological distress and lower self‐esteem, subjective evaluation of health, satisfaction with life and personal well‐being). Group discrimination, in contrast, was associated with poorer well‐being but not health outcomes (lower subjective evaluation of health and personal well‐being). These findings corroborate previous research and highlight the corrosive effect of discrimination towards health and well‐being among Pacific communities in New Zealand.
Migrants straddling the “here” and “there”: Explorations of habitus and hybrid identities among Sri Lankan migrants in New Zealand
Authors: Cassim Shemana , Stolte Ottilie , Hodgetts Darrin
Published: August 2019

Migrant settlement is of particular interest to the field of psychology due to a notable increase in the movement of people over the past few decades. This article explores the ways in which Sri Lankan migrants in New Zealand establish a sense of continuity between the host nation and country of origin. The theoretical framework for this research is informed by elements of ethnographic and indigenous research. We provide a rich understanding of migrant experiences that foregrounds the agency and resilience of migrants, and acknowledges the complexities of the notion of identity and migrant settlement. We explore complex, fluid, and hybrid cultural identities as experienced by Sri Lankan migrants and their negotiations of space and place, material practices, and objects of significance, such as an educational institution, antique dinnerware, and furniture with colonial origins. The present research thereby, argues for the need to acknowledge both the historical and current contexts that shape migrants' sense of habitus and cultural identities.
Extraction of Natural Fragrance Ingredients: History Overview and Future Trends
Authors: Burger Pauline , Plainfossé Hortense , Brochet Xavier , Chemat Farid , Fernandez Xavier
Published: August 2019

For centuries, perfumes consisted in a combination of natural ingredients, mainly of plant origin. From the 19th century on, the advent of organic synthesis enabled the deployment of multiple synthetic olfactory notes, enriching significantly the perfumers’ portfolio. Chemistry is ever since the foundation of modern perfumery. However, sustainable‐minded consumers, massively rejecting synthetics for safety and ecological issues, engaged a global return to nature in numerous sectors, and the fragrance industry is not outdone. Sustainable extraction of natural products, making use of innovative technologies, process intensification and agro‐based solvents, constitutes the answer to develop eco‐conceived fragrant ingredients covering every olfactory family without endangering biodiversity any further. The objective of this review is to draw a clear picture of where those technological advances are today and to assess the ones that may be effectively transposed at the industrial scale tomorrow.
The CTIP‐mediated repair of TNF‐α‐induced DNA double‐strand break was impaired by miR‐130b in cervical cancer cell
Authors: Yang Lei , Yang Bin , Wang Yanli , Liu Tao , He Zhankun , Zhao Hejun , Xie Lili , Mu Hong
Published: August 2019

Chemotherapeutic drugs that induce DNA damage have the potential to kill cancer cells, but DNA repair protects cells from damage‐induced cell death. Thus, eliminating DNA repair is a potential approach to overcome cell drug resistance. In this study, we observed that the gene expression of C‐terminal binding protein interacting protein (CTIP) was promoted by TNF‐α stimulation and prevented TNF‐α‐induced double‐strand breaks (DSBs) in the genomes of cervical cancer cells. The putative miR‐130b targeted site within 3′ untranslated region (UTR) of CTIP mRNA was identified through in silico analysis and confirmed based on experimental data. By targeting the CTIP gene, miR‐130b caused the accumulation of DSBs and accelerated cell apoptosis in combination with poly ADP ribose polymerase (PARP) inhibitors. Additionally, overexpression of the CTIP gene elevated cancer cell viability by promoting proliferation while miR‐130b antagonized CTIP‐stimulated cell reproduction. Consequently, miR‐130b destruction of DNA repair should be employed as a strategy to treat cervical cancer.

Significance of the study

Cervical cancer threatens the health of women all over the world. In this study, we observed that miR‐130b was able to cause the accumulation of DNA double‐strand breaks through suppressing the gene expression of C‐terminal binding protein interacting protein and to accelerate cell apoptosis by preventing DNA damage repairs in cervical cancer cells. As far as we know, the impact of miR‐130b on the DNA double‐strand break repair and on the cell apoptosis induced by the destruction of DNA repair in cervical cancer cells was firstly documented. It is reasonable to believe that miR‐130b destruction of DNA repair may be employed as a strategy to treat cervical cancer in the future.