bluuebunny/crossref_metadata_2025 huggingface dataset:
One‐Step Selective Adhesive Transfer Printing for Scalable Fabrication of Stretchable Electronics
Authors: Peng Peng , Wu Kang , Lv Liangxiong , Guo Chuan Fei , Wu Zhigang
Published: January 2018

Transferring patterned thin foil structures onto an elastic substrate is one important process for realizing heterogeneous integration and high‐performance stretchable electronics. Usually, specific equipment and long learning curve are necessary for transferring fragile micro/nanostructures. In this work, a one‐step selective transfer printing technique can selectively transfer fine metal structure from a donor substrate to a sticky polydimethylsiloxane receiver by tuning its adhesion force and hence corresponded energy release rate (G). The method greatly simplifies the transferring process compared with traditional ones. The selective transferring lies in the fact that a wider line requires a higher energy release rate, based on experimental and numerical analysis. With the selective adhesive transferring technique, a few simple stretchable devices and structures are fabricated, where a device does not exhibit any fatigue after stretching for 10 000 cycles under a 40% strain. Further, this method does not use any new specific equipment and is believed to be a reliable and cost‐effective technique for potential mass production of stretchable electronics.
Fast Prototyping of Silica Glass Microfluidic Chips: The Sol–Gel Route
Authors: Levant Michael , Château Denis , Parola Stephane , Bartolo Denis
Published: January 2018

A combination of material, patterning, and sealing method is introduced to replicate and assemble monolithic microfluidic chips made of hybrid silica glass (HSG). First, it is shown how to prepare sols suited to the replication of complex geometries out of range of conventional etching methods. Second, it is shown how to tailor the surface properties of HSG devices. The performances and the simplicity of this fast prototyping method are demonstrated using quantitative mechanical, optical, and physicochemical characterization techniques and benchmark microfluidic experiments. Finally, the high potential of HSG microfluidics to oil‐recovery and chemistry applications in benchmark experiments on crude oils is established.
Adaptable Microcontact Printing via Photochromic Optical‐Saturable Lithography
Authors: Pariani Giorgio , Castagna Rossella , Oggioni Luca , Colella Letizia , Nardi Andrea , Anzani Stefano , Bertarelli Chiara , Bianco Andrea
Published: January 2018

A versatile and easily customizable mold platform for the microcontact printing of 1D and 2D patterns of dyes is developed. The mold is obtained by optical‐saturable lithography, which is optimized to give a fast process on millimeter size areas. Supported by a kinetic and an electro–magnetic model, 1D and 2D patterns are designed and successfully transferred on the photoresist layer and copied with polydimethylsiloxane (PDMS) to fabricate stamps that are to be used in the printing process. Fluorescence patterning, by means of these PDMS stamp, is validated and compared with the stamp structure.
Room‐Temperature Plasma‐Assisted Inkjet Printing of Highly Conductive Silver on Paper
Authors: Knapp Caroline E. , Chemin Jean‐Baptiste , Douglas Samuel P. , Ondo Dominique Abessolo , Guillot Jérôme , Choquet Patrick , Boscher Nicolas D.
Published: January 2018

For the first time, the plasma‐assisted inkjet printing of metal‐organic decomposition (MOD) inks is demonstrated to provide an easily up‐scalable method toward the deposition of highly conductive silver features on paper. Atmospheric plasma sintering methods provide a fast and effective alternative to thermal treatment. This high‐speed, room‐temperature approach ensures the immediate conversion of the MOD inks after printing and thus overcomes wetting issues typically encountered in porous substrates—a mechanical solution to a chemical problem.
Spectroscopy and Biosensing with Optically Resonant Dielectric Nanostructures
Authors: Krasnok Alex , Caldarola Martín , Bonod Nicolas , Alú Andrea
Published: January 2018

Resonant dielectric nanoparticles made of materials with large positive dielectric permittivity, such as Si, GaP, GaAs, have become a powerful platform for modern light science, enabling various fascinating applications in nanophotonics and quantum optics. In addition to light localization at the nanoscale, dielectric nanostructures provide electric and magnetic resonant responses throughout the visible and infrared spectrum, low dissipative losses and optical heating, low doping effect, and absence of quenching, which are interesting for spectroscopy and biosensing applications. This review presents state‐of‐the‐art applications of optically resonant high‐index dielectric nanostructures as a multifunctional platform for light–matter interactions. Nanoscale control of quantum emitters and applications for enhanced spectroscopy including fluorescence spectroscopy, surface‐enhanced Raman scattering, biosensing, and lab‐on‐a‐chip technology are surveyed. The theoretical background underlying these effects is described, realizations of specific resonant dielectric nanostructures and hybrid excitonic systems are overviewed, and an outlook of the challenges in this field, which remain open to future research, is provided.
Synthesis of Iron Phosphate and Their Composites for Lithium/Sodium Ion Batteries
Authors: Shao Jinying , Li Xinran , Wei Jilei , Pang Huan , Chen Changyun
Published: January 2018

High‐performance electric energy storage material has recently developed due to the attention for sustainable development. As ecofriendly energy storage device, lithium ion batteries and sodium ion batteries deserve more concern today. FePO4 and NaFePO4 share similar advantages such as easy preparation, abundant, and inexpensive, so they can be ideal materials for lithium/sodium ion batteries. This review is focused on recent progresses in nanostructured FePO4/NaFePO4‐based nanomaterial as cathode materials for lithium/sodium ion batteries. FePO4‐based materials contain crystalline and amorphous pure FePO4 nanomaterial, FePO4/C compounds, and other novel materials with unique morphologies. NaFePO4‐based materials contain olivine NaFePO4, Na4FeP2O7, and so on. They own unique properties, including preferable energy density, cycling performance, electrical conductivity, and charge/discharge stability. This review is designed to summarize the synthesis, morphology, and electrochemical property and application of FePO4‐based and NaFePO4‐based nanomaterials. There exist relations among the structure, property, and storage, which is also introduced. Furthermore, this review assesses the challenges and outlooks of FePO4/NaFePO4‐based nanomaterial for future development; it also sheds light on appropriate development direction of advanced rechargeable batteries with a focus on FePO4/NaFePO4‐based nanomaterial.
Manifestation of accelerator type and vulcanization system on the properties of silica‐reinforced SBR/devulcanize SBR blend vulcanizates
Authors: Ghosh Joyeeta , Ghorai Soumyajit , Jalan Arun K. , Roy Madhusudan , De Debapriya
Published: January 2018

Mechanochemically devulcanized styrene‐butadiene rubber, prepared by bis[3‐(triethoxysilyl)propyl]‐tetrasulfide, was blended with fresh styrene‐butadiene rubber. The ultimate properties of the blend vulcanizate depend on a three‐dimensional network structure formed during vulcanization which relies mainly on the accelerator and the vulcanizing system used during compounding. The effect of monosulfide, disulfide, and poly sulfide cross‐links, which primarily gets controlled by different accelerators such as N‐cyclohexyl‐benzothiazyl‐sulfenamide (CBS), tetramethylthiuram disulfide, 2‐mercaptobenzothiazol, and N‐tert‐butyl‐2‐benzothiazyl‐sulfonamide on mechanical, thermal, and dielectric behavior of the blend vulcanizates, was studied. The results indicate that the semi‐efficient CBS vulcanizate has superior mechanical and thermal properties. Therefore, the effect of accelerator to sulfur ratio, that is, (accelerator/sulfur) on the properties of the blend vulcanizates was determined. It is to highlight that a distinctive correlation is observed between the cross‐link types and the fraction of immobilized polymer chains of the blend vulcanizates. Further, the effect of cross‐link types on segmental dynamics of the blend vulcanizates was studied through broadband dielectric spectroscopy. The SEM micrographs indicate the homogeneity of the blend vulcanizates.
Cassava starch‐graft‐poly(acrylonitrile)‐coated urea fertilizer with sustained release and water retention properties
Authors: Jyothi Alummoottil N. , Pillai Swetha S. , Aravind Mancharyamkunnath , Salim Salma A. , Kuzhivilayil Susan John
Published: January 2018

Cassava starch‐graft‐poly(acrylonitrile) samples were synthesized by a free radical‐initiated polymerization reaction, and urea fertilizer was coated with these grafted starches to obtain the dual benefit of sustained release and water retention properties. A response surface design was used to optimize the synthetic conditions of starch‐graft‐copolymers to maximize the slow nutrient release and water absorbency. The FT‐IR analysis confirmed the grafting reaction, and scanning electron micrographs revealed the ultrastructure of polymer coating. The release of nitrogen in soil from coated urea was more sustained than that from uncoated urea and it varied with grafting level of the polymer. The uncoated urea showed almost complete release of nitrogen by 1 month, whereas %N release was in the range of 69.8%–78.3% from the grafted starch‐coated urea even after 108 days of incubation. The water retention capacity of the coated urea ranged from 74.2% to 426.6% and it decreased with increase in % grafting of the coating material.
Aluminum Chloride‐Graphite Batteries with Flexible Current Collectors Prepared from Earth‐Abundant Elements
Authors: Wang Shutao , Kravchyk Kostiantyn V. , Filippin Alejandro N. , Müller Ulrich , Tiwari Ayodhya N. , Buecheler Stephan , Bodnarchuk Maryna I. , Kovalenko Maksym V.
Published: January 2018

In the search for low‐cost and large‐scale stationary storage of electricity, nonaqueous aluminum chloride‐graphite batteries (AlCl3‐GBs) have received much attention due to the high natural abundances of their primary constituents, facile manufacturing, and high energy densities. Much research has focused on the judicious selection of graphite cathode materials, leading to the most notable recent advances in the performance of AlCl3‐GBs. However, the major obstacle to commercializing this technology is the lack of oxidatively stable, inexpensive current collectors that can operate in chloroaluminate ionic liquids and are composed of earth‐abundant elements. This study presents the use of titanium nitride (TiN) as a compelling material for this purpose. Flexible current collectors can be fabricated by coating TiN on stainless steel or flexible polyimide substrates by low‐cost, rapid, scalable methods such as magnetron sputtering. When these current collectors are used in AlCl3‐GB coin or pouch cells, stable cathodic operation is observed at voltages of up to 2.5 V versus Al3+/Al. Furthermore, these batteries have a high coulombic efficiency of 99.5%, power density of 4500 W kg−1, and cyclability of at least 500 cycles.
On the Molecular Origin of Charge Separation at the Donor–Acceptor Interface
Authors: Sini Gjergji , Schubert Marcel , Risko Chad , Roland Steffen , Lee Olivia P. , Chen Zhihua , Richter Thomas V. , Dolfen Daniel , Coropceanu Veaceslav , Ludwigs Sabine , Scherf Ullrich , Facchetti Antonio , Fréchet Jean M. J. , Neher Dieter
Published: January 2018

Fullerene‐based acceptors have dominated organic solar cells for almost two decades. It is only within the last few years that alternative acceptors rival their dominance, introducing much more flexibility in the optoelectronic properties of these material blends. However, a fundamental physical understanding of the processes that drive charge separation at organic heterojunctions is still missing, but urgently needed to direct further material improvements. Here a combined experimental and theoretical approach is used to understand the intimate mechanisms by which molecular structure contributes to exciton dissociation, charge separation, and charge recombination at the donor–acceptor (D–A) interface. Model systems comprised of polythiophene‐based donor and rylene diimide‐based acceptor polymers are used and a detailed density functional theory (DFT) investigation is performed. The results point to the roles that geometric deformations and direct‐contact intermolecular polarization play in establishing a driving force (energy gradient) for the optoelectronic processes taking place at the interface. A substantial impact for this driving force is found to stem from polymer deformations at the interface, a finding that can clearly lead to new design approaches in the development of the next generation of conjugated polymers and small molecules.
Hybrid Dye‐Titania Nanoparticles for Superior Low‐Temperature Dye‐Sensitized Solar Cells
Authors: Kunzmann Andreas , Valero Silvia , Sepúlveda Ángel E. , Rico‐Santacruz Marisa , Lalinde Elena , Berenguer Jesús R. , García‐Martínez Javier , Guldi Dirk M. , Serrano Elena , Costa Rubén D.
Published: January 2018

In this work, a new strategy to design low‐temperature (≤200 °C) sintered dye‐sensitized solar cells (lt‐DSSC) is reported to enhance charge collection efficiencies (ηcoll), photoconversion efficiencies (η), and stabilities under continuous operation conditions. Realization of lt‐DSSC is enabled by the integration of hybrid nanoparticles based on TiO2‐Ru(II) complex (TiO2_Ru_IS)—obtained by in situ bottom‐up construction of Ru(II) N3 dye‐sensitized titania—into the photoelectrode. Incentives for the use of TiO2_Ru_IS are i) dye stability due to its integration into the TiO2 anatase network and ii) enhanced charge collection yield due to its significant resistance toward electron recombination with electrolytes. It is demonstrated that devices with single‐layer photoelectrodes featuring blends of P25 and TiO2_Ru_IS give rise to a 60% ηcoll relative to a 46% ηcoll for devices with P25‐based photoelectrodes. Responsible for this trend is a better charge transport and a reduced electron recombination. When using a multilayered photoelectrode architecture with a top layer based only on TiO2_Ru_IS, devices with an even higher ηcoll (74%) featuring a η of around 8.75% and stabilities of 600 h are achieved. This represents the highest values reported for lt‐DSSC to date.
How Methylammonium Cations and Chlorine Dopants Heal Defects in Lead Iodide Perovskites
Authors: Nan Guangjun , Zhang Xu , Abdi‐Jalebi Mojtaba , Andaji‐Garmaroudi Zahra , Stranks Samuel D. , Lu Gang , Beljonne David
Published: January 2018

Lead tri‐iodide methylammonium (MAPbI3) perovskite polycrystalline materials show complex optoelectronic behavior, largely because their 3D semiconducting inorganic framework is strongly perturbed by the organic cations and ubiquitous structural or chemical inhomogeneities. Here, a newly developed time‐dependent density functional theory‐based theoretical formalism is taken advantage of. It treats electron–hole and electron–nuclei interactions on the same footing to assess the many‐body excited states of MAPbI3 perovskites in their pristine state and in the presence of point chemical defects. It is shown that lead and iodine vacancies yield deep trap states that can be healed by dynamic effects, namely rotation of the methylammonium cations in response to point charges, or through slight changes in chemical composition, namely by introducing a tiny amount of chlorine dopants in the defective MAPbI3. The theoretical results are supported by photoluminescence experiments on MAPbI3−mClm and pave the way toward the design of defect‐free perovskite materials with optoelectronic performance approaching the theoretical limits.
High Activity Hydrogen Evolution Catalysis by Uniquely Designed Amorphous/Metal Interface of Core–shell Phosphosulfide/N‐Doped CNTs
Authors: Li Dong Jun , Kang Joonhee , Lee Ho Jin , Choi Dong Sung , Koo Sung Hwan , Han Byungchan , Kim Sang Ouk
Published: January 2018

A cost effective hydrogen evolution reaction (HER) catalyst that does not use precious metallic elements is a crucial demand for environment‐benign energy production. The family of earth‐abundant transition metal compounds of nitrides, carbides, chalcogenides, and phosphides is one of the promising candidates for such a purpose, particularly in acidic conditions. However, its catalytic performance is still needed to be enhanced through novel material designs and crystalline engineering. Herein, a chemically and electronically coupled transition metal phosphosulfide/N‐doped carbon nanotubes (NCNT) hybrid electrocatalyst is fabricated via a two‐step synthesis. The uniquely designed synthesis leads to the material morphology featuring a core–shell structure, in which the crystalline metal phosphide core is surrounded by an amorphous phosphosulfide nanoshell. Notably, due to the favorable modification of chemical composition and surface properties, core–shell CoP@PS/NCNT exhibits the noticeable HER activity of approximately −80 mV @ −10 mA cm−2 with excellent durability, which is one of the highest active nonnoble metal electrocatalysts ever reported thus far.
Electrochemical Activity of Hematite Phase in Full‐Cell Li‐ion Assemblies
Authors: Aravindan Vanchiappan , Lee Yun‐Sung
Published: January 2018

Exploring negative electrodes for high‐performance Li‐ion power packs and related issues that are hampering their commercialization is a particularly important topic of research. This study investigates the electrochemical activity of low‐cost and typical conversion‐type hematite (α‐Fe2O3) anodes in practical assemblies, namely, full‐cell configurations. Numerous studies have reported improvements in the electrochemical activity of α‐Fe2O3 in half cells with Li by tuning the morphology or formulating composites with carbonaceous materials. However, these studies are not sufficient to market them for practical assemblies with conventional cathodes like LiCoO2, LiMn2O4, LiFePO4 and its derivatives, mainly because of large polarization problems, such as, hysteresis, irreversible capacity loss, volume variation, and capacity fading. Eliminating these issues in the fabrication of full cells is necessary, and this study reviews relevant research activities and discusses future prospects in the field.
A New Perspective on the Role of A‐Site Cations in Perovskite Solar Cells
Authors: Myung Chang Woo , Yun Jeonghun , Lee Geunsik , Kim Kwang S.
Published: January 2018

As the race toward higher efficiency for inorganic/organic hybrid perovskite solar cells (PSCs) is becoming highly competitive, a design scheme to maximize carrier transport toward higher power efficiency has been urgently demanded. In this study, a hidden role of A‐site cations of PSCs in carrier transport, which has been largely neglected is unraveled, i.e., tuning the Fröhlich electron–phonon (e–ph) coupling of longitudinal optical (LO) phonon by A‐site cations. The key for steering Fröhlich polaron is to control the interaction strength and the number of proton (or lithium) coordination to halide ions. The coordination to I− alleviates electron–phonon scattering by either decreasing the Born effective charge or absorbing the LO motion of I. This novel principle discloses low electron–phonon coupling in several promising organic cations including hydroxyl–ammonium cation (NH3OH+), hydrazinium cation (NH3NH2+) and possibly Li+ solvating methylamine (Li+∙∙∙NH2CH3), on a par with methyl–ammonium cations. A new perspective on the role of A‐site cations could help in improving power efficiency and accelerating the application of PSCs.
Multistate Luminescent Solar Concentrator “Smart” Windows
Authors: Sol Jeroen A. H. P. , Timmermans Gilles H. , van Breugel Abraham J. , Schenning Albertus P. H. J. , Debije Michael G.
Published: January 2018

A supertwist liquid crystalline luminescent solar concentrator (LSC) “smart” window is fabricated which can be switched electrically between three states: one designed for increased light absorption and electrical generation (the “dark” state), one for transparency (the “light” state), and one for enhanced haziness (“scattering” state). In the scattering state, the absorption and edge emissions decrease while the face emissions are enhanced. This new LSC “smart” window state can find application as a privacy feature in housing, but could also allow for a new “smart” window application as a diffuse glazing to increase plant growth in horticultural applications.
Bioinspired Surface Layer for the Cathode Material of High‐Energy‐Density Sodium‐Ion Batteries
Authors: Jo Chang‐Heum , Jo Jae‐Hyeon , Yashiro Hitoshi , Kim Sun‐Jae , Sun Yang‐Kook , Myung Seung‐Taek
Published: January 2018

Cathode materials are usually active in the range of 2–4.3 V, but the decomposition of the electrolytic salt above 4 V versus Na+/Na is common. Arguably, the greatest concern is the formation of HF after the reaction of the salts with water molecules, which are present as an impurity in the electrolyte. This HF ceaselessly attacks the active materials and gradually causes the failure of the electrode via electric isolation of the active materials. In this study, a bioinspired β‐NaCaPO4 nanolayer is reported on a P2‐type layered Na2/3[Ni1/3Mn2/3]O2 cathode material. The coating layers successfully scavenge HF and H2O, and excellent capacity retention is achieved with the β‐NaCaPO4‐coated Na2/3[Ni1/3Mn2/3]O2 electrode. This retention is possible because a less acidic environment is produced in the Na cells during prolonged cycling. The intrinsic stability of the coating layer also assists in delaying the exothermic decomposition reaction of the desodiated electrodes. Formation and reaction mechanisms are suggested for the coating layers responsible for the excellent electrode performance. The suggested technology is promising for use with cathode materials in rechargeable sodium batteries to mitigate the effects of acidic conditions in Na cells.
New Strategy for Two‐Step Sequential Deposition: Incorporation of Hydrophilic Fullerene in Second Precursor for High‐Performance p‐i‐n Planar Perovskite Solar Cells
Authors: Xu Guiying , Xue Rongming , Chen Weijie , Zhang Jingwen , Zhang Moyao , Chen Haiyang , Cui Chaohua , Li Hongkun , Li Yaowen , Li Yongfang
Published: January 2018

In p‐i‐n planar perovskite solar cells (pero‐SCs) based on methylammonium lead iodide (MAPbI3) perovskite, high‐quality MAPbI3 film, perfect interfacial band alignment and efficient charge extracting ability are critical for high photovoltaic performance. In this work, a hydrophilic fullerene derivative [6,6]‐phenyl‐C61‐butyric acid‐(3,4,5‐tris(2‐(2‐(2‐methoxyethoxy)ethoxy)ethoxy)phenyl)methanol ester (PCBB‐OEG) is introduced as additive in the methylammonium iodide precursor solution in the preparation of MAPbI3 perovskite film by two‐step sequential deposition method, and obtained a top‐down gradient distribution with an ultrathin top layer of PCBB‐OEG. Meanwhile, a high‐quality perovskite film with high crystallinity, less trap‐states, and dense‐grained uniform morphology can well grow on both hydrophilic (poly(3,4‐ethylenedioxythiophene)/poly(styrenesulfonic acid)) and hydrophobic (polytriarylamine, PTAA) hole transport layers. When the PCBB‐OEG‐containing perovskite film (pero‐0.1) is prepared in a p‐i‐n planar pero‐SC with the configuration of ITO/PTAA/pero‐0.1/[6,6]‐phenyl‐C61‐butyric acid methyl ester/Al, the device delivers a promising power conversion efficiency (PCE) of 20.2% without hysteresis, which is one of the few PCE over 20% for the p‐i‐n planar pero‐SCs. Importantly, the pero‐0.1‐based device shows an excellent stability that can retain 98.4% of its initial PCE after being exposed for 300 h under ambient atmosphere with a high humidity, and the flexible pero‐SCs based on pero‐0.1 also demonstrate a promising PCE of 18.1%.
Atomic layer deposition fabricating of ceramic nanofiltration membranes for efficient separation of dyes from water
Authors: Chen He , Wu Shanshan , Jia Xiaojuan , Xiong Sen , Wang Yong
Published: January 2018

To meet the strong need for highly efficient and controllable manufacturing methods to ceramic nanofiltration (NF) membranes, we use atomic layer deposition (ALD) to prepare NF membranes by tightening ultrafiltration (UF) membranes. We confine the ALD deposition of TiO2 to the near‐surface region of substrate UF membranes. The pores (∼5 nm) in the selective layers are progressively reduced, thus transforming the original UF membranes to NF ones at acceptable expense of permeability. A molecular‐weight‐cut‐off (MWCO) down to 890 Da is obtained after merely 40 cycles and the water permeability remains as high as 32 L·m−2·h−1·bar−1. MWCOs can be flexibly tuned by altering ALD cycles, which is lowered down to 410 Da with 60 ALD cycles. The deposited membranes are used to remove dyes from water and they show significantly enhanced rejection to negatively charged dyes. © 2018 American Institute of Chemical Engineers AIChE J, 64: 2670–2678, 2018
Real‐time multivariable model predictive control for steam‐assisted gravity drainage
Authors: Purkayastha Sagar N. , Gates Ian D. , Trifkovic Milana
Published: January 2018

Thermal recovery techniques, such as steam‐assisted gravity drainage (SAGD), are used to recover the majority of the crude bitumen, in Western Canada. However, suboptimal production techniques have led to a large carbon footprint and a subsequent search for more efficient extraction techniques, than open loop manual control. This article summarizes research on the comparison of performance of a novel multi‐input multioutput (MIMO) model predictive controller (MPC) with steam trap and oil rate controls with a multi‐input single output (MISO) MPC with only steam trap control. An appropriate system identification technique was also used for periodic model update in compliance with changing system behavior. The real‐time control study was made possible by establishing a bidirectional communication between computer modeling group STARSTM (virtual reservoir) and MATLAB (onsite controller) software. The results show a 171% improvement in oil recovery for the novel MIMO MPC over the MISO MPC. © 2018 American Institute of Chemical Engineers AIChE J, 64: 3034–3041, 2018
Skeletal muscle mass in human athletes: What is the upper limit?
Authors: Abe Takashi , Buckner Samuel L. , Dankel Scott J. , Jessee Matthew B. , Mattocks Kevin T. , Mouser J. Grant , Loenneke Jeremy P.
Published: January 2018

Objectives

To examine the amount of absolute and relative skeletal muscle mass (SM) in large sized athletes to investigate the potential upper limit of whole body muscle mass accumulation in the human body.

Methods

Ninety‐five large‐sized male athletes and 48 recreationally active males (control) had muscle thickness measured by ultrasound at nine sites on the anterior and posterior aspects of the body. SM was estimated from an ultrasound‐derived prediction equation. Body density was estimated by hydrostatic weighing technique, and then body fat percentage and fat‐free mass (FFM) were calculated. We used the SM index and FFM index to adjust for the influence of standing height (ie, divided by height squared).

Results

Ten of the athletes had more than 100 kg of FFM, including the largest who had 120.2 kg, while seven of the athletes had more than 50 kg of SM, including the largest who had 59.3 kg. FFM index and SM index were higher in athletes compared to controls and the percentage differences between the two groups were 44% and 56%, respectively. The FFM index increased linearly up to 90 kg of body mass, and then the values leveled off in those of increasing body mass. Similarly, the SM index increased in a parabolic fashion reaching a plateau (approximately 17 kg/m2) beyond 120 kg body mass.

Conclusions

SM index may be a valuable indicator for determining skeletal muscle mass in athletes. A SM index of approximately 17 kg/m2 may serve as the potential upper limit in humans.
Maternal breast and body symmetry in pregnancy and offspring condition
Authors: Żelaźniewicz Agnieszka , Pawłowski Bogusław
Published: January 2018

Objectives

Fluctuating asymmetry (FA) is hypothesized to reflect the level of an individual's developmental instability, and therefore genetic quality. As a potential signal of biological condition, female body (including breast) symmetry was shown to be perceived as more attractive in mate choice context. If symmetry reflects a woman's genetic quality, it is possible that FA, similarly to other maternal anthropometric cues of biological condition (e.g., body height or waist‐to‐hip ratio), may be also related to her offspring condition.

Materials and Methods

To test this, breast and body asymmetry was measured in 93 pregnant women in the 1st, 2nd, and 3rd pregnancy trimester. Child's birth weight, length, chest and head circumference, information on the Apgar score, congenital malformations, and birth complications was taken from hospital records. The relationships between offspring birth characteristics and maternal breast FA and body FA were analyzed separately, controlled for a child's sex and maternal weight in pregnancy.

Results

Breast asymmetry was not a predictor of a child's neonatal condition assessed from morphological parameters at birth. Asymmetry of maternal non‐ornamental body characteristcs, commonly used to assess body FA, correlated negatively with a child's weight, head and chest circumference at birth.

Discussion

A composite asymmetry index of eight body traits, non‐sexually selected characteristics, seems to be a better predictor of a woman's ability to invest in fetus during pregnancy than breast asymmetry, sexual ornamentation that is perceived as a signal of a woman's attractiveness and biological condition.
Let's talk about stress, baby! Infant‐feeding practices and stress in the ancient Atacama desert, Northern Chile
Authors: King Charlotte L. , Halcrow Siân E. , Millard Andrew R. , Gröcke Darren R. , Standen Vivien G. , Portilla Marco , Arriaza Bernardo T.
Published: January 2018

Aims and objectives

The transition to an agricultural economy is often presumed to involve an increase in female fertility related to changes in weaning practice. In particular, the availability of staple crops as complementary foods is hypothesized to allow earlier weaning in agricultural populations. In this study, our primary aim is to explore whether this model fits the agricultural transition in the Atacama Desert using incremental isotopic analysis. A secondary aim of this study is to identify isotopic patterns relating to weaning, and assess how these may be differentiated from those relating to early life stress.

Materials and methods

We use incremental isotopic analysis of dentine to examine changes in δ15N and δ13C values from infancy and childhood in sites of the Arica region (n = 30). We compare individuals from pre‐agricultural and agricultural phases to establish isotopic patterns and relate these patterns to maternal diet, weaning trajectory and physiological stress.

Results

We find that there is no evidence for systematic temporal or geographic variation in incremental isotopic results. Instead, results from all time periods are highly variable, with weaning completed between 1.5 and 3.5 years. Characteristics of the incremental profiles indicate that bothin uteroand postnatal stress were a common part of the infant experience in the Atacama.

Discussion

In the Atacama Desert it appears that the arrival of agricultural crops did not result in uniform shifts in weaning behavior. Instead, infant and child diet seems to have been dictated by the broad‐spectrum diets of the mothers, perhaps as a way of mitigating the stresses of the harsh desert environment.
Monitoring Dissociation Kinetics during Electrophoretic Focusing to Enable High‐Specificity Nucleic Acid Detection
Authors: Zeidman Kalman Tal , Khalandovsky Rebecca , Tenenbaum Gonikman Elena , Bercovici Moran
Published: January 2018

A wide range of medical conditions can be diagnosed through sequence‐specific analysis of nucleic acids. However, a major challenge remains in detecting a specific target in samples containing a high concentration of mismatching sequences. A single‐step kinetic homogenous (free solution) assay is presented in which free sequence‐specific probes are continuously separated from probe–target hybrids during electrophoretic sample focusing, allowing monitoring of dissociation kinetics. Under these conditions, the different kinetics of targets versus mismatches result in distinct patterns of the signal (for example, linear increase for target versus exponential decay for mismatch), allowing the detection of desired sequences even in the presence of high background nucleic acid content. Additionally, an analytical model provides insight into the underlying dynamics, and allows design of assays based on this mechanism.
Densely Packed, Ultra Small SnO Nanoparticles for Enhanced Activity and Selectivity in Electrochemical CO2 Reduction
Authors: Gu Jun , Héroguel Florent , Luterbacher Jeremy , Hu Xile
Published: January 2018

Controlling the selectivity in electrochemical CO2 reduction is an unsolved challenge. While tin (Sn) has emerged as a promising non‐precious catalyst for CO2 electroreduction, most Sn‐based catalysts produce formate as the major product, which is less desirable than CO in terms of separation and further use. Tin monoxide (SnO) nanoparticles supported on carbon black were synthesized and assembled and their application in CO2 reduction was studied. Remarkably high selectivity and partial current densities for CO formation were obtained using these SnO nanoparticles compared to other Sn catalysts. The high activity is attributed to the ultra‐small size of the nanoparticles (2.6 nm), while the high selectivity is attributed to a local pH effect arising from the dense packing of nanoparticles in the conductive carbon black matrix.
Amipurimycin: Total Synthesis of the Proposed Structures and Diastereoisomers
Authors: Wang Shengyang , Sun Jiansong , Zhang Qingju , Cao Xin , Zhao Yachen , Tang Gongli , Yu Biao
Published: January 2018

The proposed diastereoisomers (1 a–d) together with their C8′‐epimers (1 e–h) of amipurimycin, a unique antifungal peptidyl nucleoside antibiotic, have been synthesized for the first time. The synthetic approach is efficient and stereodivergent, and features a stereoselective aldol condensation to build the branched C9 sugar amino acid skeleton and a regio‐ and stereocontrolled gold(I)‐catalyzed N‐glycosylation to furnish the purine nucleoside. Analysis of the NMR data suggests that the previously assigned configuration of the tertiary C3′ in amipurimycin should be of opposite configuration.
Catalytic Gas‐Phase Production of Lactide from Renewable Alkyl Lactates
Authors: De Clercq Rik , Dusselier Michiel , Makshina Ekaterina , Sels Bert F.
Published: January 2018

A new route to lactide, which is a key building block of the bioplastic polylactic acid, is proposed involving a continuous catalytic gas‐phase transesterification of renewable alkyl lactates in a scalable fixed‐bed setup. Supported TiO2/SiO2 catalysts are highly selective to lactide, with only minimal lactide racemization. The solvent‐free process allows for easy product separation and recycling of unconverted alkyl lactates and recyclable lactyl intermediates. The catalytic activity of TiO2/SiO2 catalysts was strongly correlated to their optical properties by DR UV/Vis spectroscopy. Catalysts with high band‐gap energy of the supported TiO2 phase, indicative of a high surface spreading of isolated Ti centers, show the highest turnover frequency per Ti site.
A Three‐Component Organometallic Tyrosine Bioconjugation
Authors: Ohata Jun , Miller Mary K. , Mountain Courtney M. , Vohidov Farrukh , Ball Zachary T.
Published: January 2018

Metal‐based bioconjugation linkages represent a little‐studied approach to protein functionalization that provides novel reactivity, stability, and function. Described is an organometallic bioconjugation, employing rhodium(III) salts, to link boronic acids with tyrosine residues by an arene complex. Both peptides and proteins are amenable to the mild bioconjugation in aqueous media, allowing incorporation of useful functionalities, such as affinity handles or fluorophores. Because of the metastability of the inorganic linkage, the conjugates are susceptible to cleavage by nucleophilic redox mediators but are stable toward typical biological conditions.
Palladium‐Catalyzed Oxygenative Cross‐Coupling of Ynamides and Benzyl Bromides by Carbene Migratory Insertion
Authors: Gao Yunpeng , Wu Guojiao , Zhou Qi , Wang Jianbo
Published: January 2018

A palladium‐catalyzed oxygenative cross‐coupling of ynamides and benzyl bromides has been developed. After subsequent hydrogenation, α,α‐disubstituted amide derivatives were obtained in good yields. Migratory insertion of α‐oxo palladium carbene species, generated by intermolecular oxidation, is proposed as the key step in this reaction. The study demonstrates the potential of ynamides to serve as carbene precursors in palladium‐catalyzed C−C bond‐forming cross‐coupling reactions.
Confined Self‐Assembly in Two‐Dimensional Interlayer Space: Monolayered Mesoporous Carbon Nanosheets with In‐Plane Orderly Arranged Mesopores and a Highly Graphitized Framework
Authors: Wang Jie , Xu Yunling , Ding Bing , Chang Zhi , Zhang Xiaogang , Yamauchi Yusuke , Wu Kevin C.‐W.
Published: January 2018

Although two‐dimensional (2D) carbon materials are widely investigated, a well‐defined 2D carbon nanosheet with an ordered mesostructure has rarely been realized. Monolayer‐ordered mesoporous carbon nanosheets (OMCNS) were prepared through confinement assembly of resol and F127 in the interlayer of montmorillonite (MONT). The nanoscale distance of the interlayer space of MONT only allow the assembly of resol and F127 in the same plane, leading to ordered mesopores perpendicular to carbon nanosheets, and favor the formation of sp2 carbon, resulting in a high degree of graphitization. The mesopores on the carbon nanosheets provide efficient ion diffusion, and the high degree of graphitization provides a fast electron‐transport route, enabling OMCNS as excellent electrode materials for electric double layer capacitors.
Preparation of submicrometer mesoporous iron–tin oxide hydroxide and its flame‐retardant and smoke‐suppressant properties on flexible poly(vinyl chloride)
Authors: Wu Jing , Sun Jianhong , Jiao Yunhong , Hu Weidong , Xu Jianzhong
Published: January 2018

A submicrometer mesoporous structured iron–tin oxide hydroxide [FeSnO(OH)5] was synthesized via a hydrothermal method and characterized by X‐ray diffraction, scanning electron microscopy, transmission electron microscopy, and the Brunauer–Emmett–Teller method. Blank poly(vinyl chloride) (PVC) and a flexible PVC treated with FeSnO(OH)5were investigated by limiting oxygen index (LOI) testing, cone calorimetry testing (CONE), tensile properties testing, and thermogravimetric analysis (TGA)–differential scanning calorimetry. The PVC sample treated with 5 phr FeSnO(OH)5(PVC5) showed the best integration properties among the studied samples. Compared with those of the untreated PVC sample, the LOI value of PVC5 increased 5.6%, and its tensile strength also improved; the average heat‐release rate, average specific extinction area, and total smoke production of PVC5 decreased about 13.4, 28.0, and 48.8%, respectively. The char residue of PVC5 after CONE contained oxides and chlorides and was dense; this reduced the release of hydrogen chloride. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2018,135, 46218.
A gross anatomy flipped classroom effects performance, retention, and higher‐level thinking in lower performing students
Authors: Day Leslie J.
Published: January 2018

A flipped classroom is a growing pedagogy in higher education. Many research studies on the flipped classroom have focused on student outcomes, with the results being positive or inconclusive. A few studies have analyzed confounding variables, such as student's previous achievement, or the impact of a flipped classroom on long‐term retention and knowledge transfer. In the present study, students in a Doctor of Physical Therapy program in a traditional style lecture of gross anatomy (n = 105) were compared to similar students in a flipped classroom (n = 112). Overall, students in the flipped anatomy classroom had an increase in semester average grades (P = 0.01) and performance on higher‐level analytical questions (P < 0.001). Long‐term retention and knowledge transfer was analyzed in a subsequent semester's sequenced kinesiology course, with students from the flipped anatomy classroom performing at a higher level in kinesiology (P < 0.05). Student's pre‐matriculation grade point average was also considered. Previously lower performing students, when in a flipped anatomy class, outperformed their traditional anatomy class counterparts in anatomy semester grades (P < 0.05), accuracy on higher‐level analytical anatomy multiple‐choice questions (P < 0.05) and performance in subsequent course of kinesiology (P < 0.05). This study suggests that the flipped classroom may benefit lower performing student's knowledge acquisition and transfer to a greater degree than higher performing students. Future studies should explore the underlying reasons for improvement in lower performing students.
A prospective study of fetal head growth, autistic traits and autism spectrum disorder
Authors: Blanken Laura M. E. , Dass Alena , Alvares Gail , van der Ende Jan , Schoemaker Nikita K. , El Marroun Hanan , Hickey Martha , Pennell Craig , White Scott , Maybery Murray T. , Dissanayake Cheryl , Jaddoe Vincent W. V. , Verhulst Frank C. , Tiemeier Henning , McIntosh Will , White Tonya , Whitehouse Andrew
Published: January 2018

Altered trajectories of brain growth are often reported in Autism Spectrum Disorder (ASD), particularly during the first year of life. However, less is known about prenatal head growth trajectories, and no study has examined the relation with postnatal autistic symptom severity. The current study prospectively examined the association between fetal head growth and the spectrum of autistic symptom severity in two large population‐based cohorts, including a sample of individuals with clinically diagnosed ASD. This study included 3,820 children from two longitudinal prenatal cohorts in The Netherlands and Australia, comprising 60 individuals with a confirmed diagnosis of ASD. Latent growth curve models were used to examine the relationship between fetal head circumference measured at three different time points and autistic traits measured in postnatal life using either the Social Responsiveness Scale or the Autism‐Spectrum Quotient. While lower initial prenatal HC was weakly associated with increasing autistic traits in the Dutch cohort, this relationship was not observed in the Australian cohort, nor when the two cohorts were analysed together. No differences in prenatal head growth were found between individuals with ASD and controls. This large population‐based study identified no consistent association across two cohorts between prenatal head growth and postnatal autistic traits. Our mixed findings suggest that further research in this area is needed. Autism Res 2018, 11: 602–612. © 2018 The Authors Autism Research published by International Society for Autism Research and Wiley Periodicals, Inc.

Lay Summary

It is not known whether different patterns of postnatal brain growth in Autism Spectrum Disorder (ASD) also occurs prenatally. We examined fetal head growth and autistic symptoms in two large groups from The Netherlands and Australia. Lower initial prenatal head circumference was associated with autistic traits in the Dutch, but not the Australian, group. No differences in head growth were found in individuals with ASD and controls when the data was combined. Our mixed findings suggest that more research in this area is needed.
Bidirectional influences of caregiver utterances and supported joint engagement in children with and without autism spectrum disorder
Authors: Bottema‐Beutel Kristen , Lloyd Blair , Watson Linda , Yoder Paul
Published: January 2018

This study examined sequential associations between pairs of caregiver talk and caregiver‐child joint engagement categories. Sequential associations quantify the extent to which one event (such as a particular type of caregiver talk) follows another event (such as a particular type of joint engagement) in a pre‐specified time window, while controlling for the chance occurrence of the sequence. Although unable to support strong conclusions about causality, the requirement of sequential analysis that key events occur within a close temporal sequence rules out alternative explanation for associations that summary‐level correlations cannot. We applied sequential analysis to observational data on 98 caregiver‐child dyads, fifty of which included a child with autism spectrum disorder (ASD). Groups were matched on mental age, and all were just beginning to develop spoken vocabulary. Sequential associations between supported joint engagement and caregiver follow‐in utterances were stronger in ASD dyads as compared to dyads with typically developing children. Further, sequential associations between utterances related to the child's focus of attention followed by higher order supported joint engagement (HSJE) were stronger than between utterances that related to the caregiver's focus of attention and HSJE, across both groups. Finally, sequential associations between follow‐in directives followed by HSJE were stronger than between follow‐in comments followed by HSJE, again across both groups of children. Autism Res 2018, 11: 755–765. © 2018 International Society for Autism Research, Wiley Periodicals, Inc.

Lay Summary

Our findings suggest that caregivers of children with autism spectrum disorder (ASD) may be particularly adept at timing their talk to follow moments of high‐level joint engagement, and that follow‐in directives are particularly facilitative of high‐level joint engagement. Future intervention work can capitalize on these findings to support high level caregiver‐child engagement around toys, which may promote development in children with ASD.