bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparative characterization of biochars produced at three selected pyrolysis temperatures from common woody and herbaceous waste streams
Authors: Askeland Matthew , Clarke Bradley , Paz-Ferreiro Jorge 
Published: April 2019

Biochar, the product of biomass pyrolysis, has been explored as a soil amendment and carbon capture vessel. Recent literature has aligned biochar as a novel sorbent for a host of environmental contaminants. Through the variation of pyrolysis conditions, biochars can be engineered to have qualities desirable in sorbents whilst maintaining their agronomic benefits. This study focuses on identifying the effects that feedstock type and process temperature have on biochar characteristics which may in turn shed light on their potential environmental applications. Using this approach, six biochars were created from two waste biomasses. The biochars exhibited wide ranges of pH (5.6–11.1), surface area (16.2–397.4 m2/g), electrical conductivity (19–2,826 µS/cm), fixed carbon (72–97%), heavy metal and polycyclic aromatic hydrocarbons (PAHs). Statistically significant trends (P < 0.05) in biochar characteristics dependent upon increasing pyrolysis temperature and feedstock type were identified. Arsenic (>13 mg/kg), chromium (>93 mg/kg), copper (>143 mg/kg) and PAH (>6 mg/kg) concentrations presented themselves as obstacles to land application in a small number of biochars with respects to International Biochar Initiative (IBI) guidelines. However, it was demonstrated that these could be eliminated through employing pyrolysis processes which encompass higher temperatures (>500 °C) and ensuring the use of contaminant-free feedstocks. The variation in surface areas, carbonized fractions and surface functional groups achieved suggest that using the correct feedstock and process, biochar could be produced in Victoria (Australia) from common organic waste streams to the ends of acting as a sorbent, soil enhancer, and a waste management strategy.
Highly Uniform Resistive Switching in HfO2 Films Embedded with Ordered Metal Nanoisland Arrays
Authors: Wang Jiaying , Li Linze , Huyan Huaixun , Pan Xiaoqing , Nonnenmann Stephen S. 
Published: April 2019

AbstractMemristors enter a critical developmental stage where emerging large‐scale integration methods face major challenges with severe switching instabilities in the oxide layer. Here, the superior uniformity is achieved within HfO2 films by embedding highly ordered metal nanoisland (NI) arrays. Embedded films exhibit a significant reduction in both SET and RESET while displaying enhanced uniformity in operating voltages and resistance states. This behavior is attributed to the concentration of electric fields along Pt and Ti NIs and their interactions with the surrounding oxide film matrix environment, which induce separate and distinct filamentary formation mechanisms that affect the stability. A method is reported to further optimize the uniformity of the SET voltage by translating the NI array position down the film‐thickness dimension towards the bottom electrode. A comparison of the density and distribution of the oxygen vacancies responsible for the formation/dissolution of conducting filaments is made via combined electrostatic force microscopy and conductive atomic force microscopy (c‐AFM) studies. Finally, complete observation of the morphological evolution of conducting filaments produced by Pt and Ti is enabled by 3D c‐AFM nanotomography and cross‐sectional scanning transmission electron microscopy–energy dispersive spectroscopy to provide direct correlations between NI‐oxide interactions and overall switching performance.
Porous Silicon Nanostructures as Effective Faradaic Electrochemical Sensing Platforms
Authors: Guo Keying , Sharma Apoorva , Toh Rou Jun , Alvárez de Eulate Eva , Gengenbach Thomas R. , Cetó Xavier , Voelcker Nicolas H. , Prieto‐Simón Beatriz 
Published: April 2019

AbstractThe electrochemical performance of porous silicon (pSi) stabilized via thermal decomposition of acetylene gas is investigated for the first time. In this study, pSi undergoes two thermal treatments at either 525 or 800 °C, which result in hydrogen‐terminated thermally hydrocarbonized pSi (THCpSi) and hydroxyl‐terminated thermally carbonized pSi (TCpSi), respectively, the latter upon dipping in hydrofluoric acid to activate the surface termination. Electrochemical characterization, using cyclic voltammetry, chronocoulometry, and electrochemical impedance spectroscopy in the presence of several redox pairs, [Fe(CN)6]3/4−, [Ru(NH3)6]2/3+, and hydroquinone/quinone, is used to demonstrate the versatility and high stability to degradation of carbon‐stabilized pSi nanostructures and their excellent electrochemical performance. Added to the large surface area, adjustable pore morphology and tailorable surface chemistry of THCpSi and TCpSi, these nanostructures demonstrate fast electron‐transfer kinetics, providing key advantages over conventional carbon electrodes. The versatile surface chemistry of THCpSi and TCpSi offer various possibilities to introduce multiple functional groups depending on the nature of the bioreceptor to be immobilized. For proof of principle, the use of a THCpSi‐based immunosensor to detect MS2 bacteriophage is demonstrated by means of electrochemical impedance spectroscopy, showing a detection limit of 4.9 pfu mL−1. Carbon‐stabilized pSi structures represent a new class of nanostructured electrodes for biosensing applications.
Electro–Chemo–Mechanical Issues at the Interfaces in Solid‐State Lithium Metal Batteries
Authors: Wang Peng , Qu Wenjie , Song Wei‐Li , Chen Haosen , Chen Renjie , Fang Daining 
Published: April 2019

AbstractEffective solid‐state interfacial contact of both the cathode and lithium metal anode with the solid electrolyte (SE) are required to improve the performance of solid‐state lithium metal batteries (SSBs). Electro–chemo–mechanical coupling (ECMC) strongly affects the interfacial stability of SSBs. On one hand, mechanical stress strongly influences interfacial contact and causes side reactions. On the other hand, electrochemical reactions such as lithium deposition cause mechanical deformation and stress at electrode/SE interfaces. To solve the degradation/failure problems of interfaces and provide guidelines to construct high‐performance SSBs, the ECMC at electrode/SE interfaces should be comprehensively investigated. In this review, the problems associated with ECMC at electrode/SE interfaces are summarized. The interfacial degradation/failure mechanisms, including the contact and electrochemical stability of interfaces, are introduced. Mechanical factors affecting interfacial contact and lithium deposition are highlighted. Experimental observation and computational analysis methods for electrode/SE interfaces are then summarized. Strategies to construct stable electrode/SE interfaces, such as assembling stress and wetting layers to improve interfacial contact, 3D SE structure, and plating stress relief to suppress lithium dendrite formation, are reviewed. The remaining challenges to better understanding ECMC and related solutions to aid SSB development are discussed.
Facile and Efficient Construction of Water‐Soluble Biomaterials with Tunable Mesoscopic Structures Using All‐Natural Edible Proteins
Authors: Wang Tao , Chen Xianfu , Zhong Qixin , Chen Zhengxing , Wang Ren , Patel Ashok R. 
Published: April 2019

AbstractDeveloping biomaterials with tunable chemical and physical properties using natural molecules is central to a wide range of applications, yet the manipulation of biomacromolecular structures toward tailorable architectures remains limited. Herein, for the first time, a set of all‐natural, ubiquitous edible protein‐based nanostructures with fascinating tunability in their mesostructures easily transformed from 3D nanonet to 2D thin sheet and to nanoparticles is presented. This is achieved by simply dissolving casein micelles and various amounts of rice proteins in an alkaline solution (pH 12), followed by neutralization to form mesoscale protein composites. The structural transitions as a result of tuning the two protein ratio are confirmed by atomic force microscopy, cryo‐transmission electron microscopy, and X‐ray diffraction. When loaded with a hydrophobic model drug, apigenin (also a food‐sourced molecule), the mesoscopic structure determines the in vivo anti‐tumor activity of apigenin. The availability and biocompatibility of the studied materials, plus simple preparation and easy manipulation of the mesostructures, have promise in designing on‐demand biochemical‐carrying materials with numerous applications.
Multiphotoluminescence from a Triphenylamine Derivative and Its Application in White Organic Light‐Emitting Diodes Based on a Single Emissive Layer
Authors: Li Xiaomeng , Cui Jieshun , Ba Qiankai , Zhang Zhe , Chen Shaoqing , Yin Guoxin , Wang Yu , Li Bobo , Xiang Guohong , Kim Kwang Soo , Xu Hu , Zhang Zhaoyu , Wang Hsing‐Lin 
Published: April 2019

AbstractWhite organic light‐emitting diode (WOLED) technology has attracted considerable attention because of its potential use as a next‐generation solid‐state lighting source. However, most of the reported WOLEDs that employ the combination of multi‐emissive materials to generate white emission may suffer from color instability, high material cost, and a complex fabrication procedure which can be diminished by the single‐emitter‐based WOLED. Herein, a color‐tunable material, tris(4‐(phenylethynyl)phenyl)amine (TPEPA), is reported, whose photoluminescence (PL) spectrum is altered by adjusting the thermal annealing temperature nearly encompassing the entire visible spectra. Density functional theory calculations and transmission electron microscopy results offer mechanistic understanding of the PL redshift resulting from thermally activated rotation of benzene rings and rotation of 4‐(phenylethynyl) phenyl)amine connected to the central nitrogen atom that lead to formation of ordered molecular packing which improves the π–π stacking degree and increases electronic coupling. Further, by precisely controlling the annealing time and temperature, a white‐light OLED is fabricated with the maximum external quantum efficiency of 3.4% with TPEPA as the only emissive molecule. As far as it is known, thus far, this is the best performance achieved for single small organic molecule based WOLED devices.
Double‐Site Ni–W Nanosheet for Best Alkaline HER Performance at High Current Density >500 mA cm−2
Authors: Wu Huan , Kong Lingqiao , Ji Yujin , Yan Junqing , Ding Yimin , Li Youyong , Lee Shuit‐Tong , Liu Shengzhong (Frank) 
Published: April 2019

AbstractThe efficiency of the alkaline hydrogen evolution reaction (HER) has remained limited. Herein, a bimetallic Ni–W catalyst fabricated by the rapid dehydration of W‐doped Ni(OH)2 is reported. The Ni–W surface exhibits the following merits for an enhanced alkaline HER: a greater number of vacant outer d‐orbitals, better discharge characteristics, and a more significant difference in H adsorption between W and Ni atoms. The free water molecules are adsorbed onto W sites, then dissociated into *OH and *H. While *OH is released into the solution, *H is re‐adsorbed by nearby Ni sites. The synergistic effect of the Ni–W surface sites imparts this catalyst with the highest activity and the best stability at high current density. Specifically, at a current density of 500 mA cm‐2, the Ni–W catalyst reduces the overpotential to 303 mV, compared with 409 mV for the state‐of‐the‐art Pt/C catalyst. Additionally, the Ni–W catalyst exhibits better long‐term stability than the state‐of‐the‐art Pt/C. Whereas the Pt activity decreases by 181 mA cm‐2 after 31 h of testing at 500 mA cm‐2, the Ni–W loses only 55 mA cm‐2 under the same conditions. Density functional theory (DFT) calculations confirm the synergistic mechanism, which can be useful for general alkaline HER processes.
Chemoselective Biohydrogenation of Alkenes in the Presence of Alkynes for the Homologation of 2‐Alkynals/3‐Alkyn‐2‐ones into 4‐Alkynals/Alkynols
Authors: Colombo Danilo , Brenna Elisabetta , Gatti Francesco G. , Ghezzi Maria Chiara , Monti Daniela , Parmeggiani Fabio , Tentori Francesca 
Published: April 2019

AbstractThe chemoselective hydrogenation of alkenes in the presence of alkynes is a very challenging transformation to achieve with traditional chemical methods. The development of an effective procedure to perform this transformation would enrich the tool‐kit available to organic chemists for the development of useful synthetic routes, and the creation of novel structural motifs. The reduction of activated alkene bonds by ene‐reductases (ERs) is completely chemoselective, because of the mechanism of the reaction. Thus, we investigated the use of ERs belonging to the Old Yellow Enzyme family for the reduction of α,β‐unsaturated aldehydes with a conjugated C≡C triple bond at the γ position. This reaction was exploited as the key step for the development of an effective homologation route to convert aryl and alkyl substituted propynals and butynones into 4‐alkynals and 4‐alkynols, avoiding some troublesome or hazardous steps of known synthetic routes.magnified image
Sex ratio and maternal age in a natural fertility, subsistence population: Daughters, sons, daughters
Authors: Rapaport Tomas , Villaseñor Fernando A. , Altman Rachel M. , Nepomnaschy Pablo A. 
Published: April 2019

AbstractObjectiveTo evaluate putative links between birth sex ratios (BSR = male:female births) and maternal age in a traditional, agricultural, natural fertility population. Metabolic energy, social support, and the costs and benefits associated with producing sons versus daughters can affect BSR. These variables fluctuate with maternal age. Most studies evaluating links between maternal age and BSR have been based on industrialized populations, which differ importantly from traditional indigenous communities in terms of the aforementioned socio‐ecological variables.Materials and methodsWe analyze data from 108 mothers and their 603 children living in an agricultural, pronatalist, Kakchiquel Mayan community.ResultsA logistic regression model, including linear and quadratic maternal age terms and women‐specific random effects, shows a nonmonotonic (p = .028) relationship between log BSR and maternal age. For maternal age ≤ 22, the upper bound of the 95% confidence interval (CI) for BSR is <1, suggesting a bias toward girls. The probability of birthing a son increased early during the average mother's reproductive career, peaked at age 31.3 (approximately 95% CI = 27.1, 35.5), and decreased as she approached her perimenopausal period (p = .014).DiscussionNo changes in mating system, population sex ratio, mortality patterns, natural disasters, social risk, or toxic exposures were observed and thus are unlikely to explain our results. At this point, age‐related changes in metabolic energy, social support, and costs and benefits associated with offspring sex cannot be excluded as possible explanations. BSR can affect growth, morbidity, and mortality. Thus, our results are relevant to numerous fields, including anthropology, ecology, demography, and public health.
Nasal cavity and maxillary sinuses form variation among modern humans of Asian descent
Authors: Evteev Andrej A. , Grosheva Alexandra N. 
Published: April 2019

AbstractObjectivesThis study explores variation, covariation, and ecogeographic pattern of the nasal cavity, maxillary sinuses, and external midfacial skeleton across 15 populations of east Asian origin inhabiting the Far East, Siberia, Alaska and Greenland.Materials and MethodsWe have collected linear measurements of the internal nasal cavity, maxillary sinus and external midfacial skeleton as well as volumes and surface areas of three‐dimensional models of the cavity. A set of seven climatic variables, mtDNA and Y‐chromosome genetic matrices and a matrix of geographic distances were also utilized.ResultsA strong association between form of the nasal cavity and climate was found, whereby all north Asian groups display increased volumes, areas and lengths of the cavity, and surface area to volume ratios (SA/V). Most of Siberian groups exhibit not only large and long, but also wide and tall nasal cavity. The Eskimo‐Aleutian speaking groups possess cavities that are vertically short and narrow but of a high SA/V ratio. The sinuses exhibit an exceptionally high level of within‐ and between‐group variation which supports the views on the sinus as an architectural byproduct. Both volume and area of the nasal cavity can be reliably estimated based on a set of simple and repeatable linear measurements.DiscussionWhile the nasal cavity and maxillary sinus are both larger in a larger facial skeleton, there is a strong inverse relationship between them at a given facial size. Our results do not support the notion that the shape of the internal nasal cavity is more strongly associated with climate compared to the external midfacial morphology.
Soybean Oil Fatty Acid Ester Estolides as Potential Plasticizers
Authors: Stolp Lucas J. , Gronlund Patrick J. , Kodali Dharma R. 
Published: April 2019

AbstractFatty acid ester estolides were synthesized from soybean oil and evaluated for plasticizer functionality in poly(vinyl chloride) (PVC). The plasticization ability of the fatty acid ester estolides depends upon the molecular features such as polarity, molecular weight, and branching. The structure of the fatty acid derivatives was modified at the ester head group with various alcohols and the estolide branch was created at the site of unsaturation. Soy fatty acid esters of methanol, iso‐butanol, 2‐ethylhexanol, and glycerol were prepared to vary the size and polarity at the ester head group. Estolides of these fatty acid esters were prepared using two synthetic routes. In the first route, the fatty acid ester was condensed with an aliphatic acid at the site of unsaturation in the presence of a strong mineral acid. In the second route, the fatty acid ester double bonds were converted to epoxy groups, which were ring opened and acetylated to form acetate estolides. The first synthetic route resulted in low‐average estolide content per fatty acid chain while the second route resulted in a higher estolide content per fatty acid chain. The fatty acid ester estolides compounded with PVC showed good plasticizer properties as evidenced by the rheological properties and reduction in glass transition temperature. The fatty acid ester estolides with a higher estolide content had better plasticizer functionality, comparable to commercial controls.
Temperature stimuli‐responsive nanoparticles from chitosan‐graft‐poly(N‐vinylcaprolactam) as a drug delivery system
Authors: Fernández‐Quiroz Daniel , Loya‐Duarte Jorge , Silva‐Campa Erika , Argüelles‐Monal Waldo , Sarabia‐Sainz Andre‐í , Lucero‐Acuña Armando , del Castillo‐Castro Teresa , San Román Julio , Lizardi‐Mendoza Jaime , Burgara‐Estrella Alexel J. , Castaneda Beatriz , Soto‐Puebla Diego , Pedroza‐Montero Martín 
Published: April 2019

ABSTRACTThis work describes the preparation of thermosensitive chitosan‐graft‐poly(N‐vinylcaprolactam) nanoparticles by ionic gelation and their potential use as a controlled drug delivery system, using doxorubicin as a model drug. A systematic study of the effect of the main processing parameters on both the size and thermoresponsive behavior of nanoparticles was investigated. The size of the particles is strongly dependent on the length of the poly(N‐vinylcaprolactam) grafted chains and the concentration of the copolymer and crosslinking agent solutions. The molecular structure of the copolymer plays an essential role in the phase transition temperature of the particles, which decreases with the length of PVCL grafted chain. The system displayed proper drug‐association parameters, and the drug‐loaded nanoparticles exhibited dose‐dependent cytotoxicity. A significant increase in the doxorubicin delivery rate was observed above the phase transition temperature (40 °C). These features indicate that these nanoparticles are suitable for the development of a new thermally controlled anti‐cancer drug delivery system. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47831.
Minimum time control of large‐scale boolean control networks with constraints
Authors: Pan Jinfeng , Feng Jun‐e , Meng Min , Zhao Jianli 
Published: April 2019

AbstractThe minimum time control that steers a large‐scale Boolean control network with constraints from an initial state to a given state is investigated. This problem is studied under the partition of the large‐scale Boolean control networks. Based on that, the problem is converted to finding the minimum time control for each subnetwork. Hence, the minimum time control for small size Boolean control networks with constraints is considered firstly. Then, a method to solve the problem for large‐scale Boolean control networks with constraints is presented. Finally, a numerical example on T‐cell receptor kinetics is given to show the effectiveness of the main results.
Application of a physiologically based pharmacokinetic model for the prediction of mirabegron plasma concentrations in a population with severe renal impairment
Authors: Konishi Kentaro , Minematsu Tsuyoshi , Nagasaka Yasuhisa , Tabata Kenji 
Published: April 2019

AbstractWe previously verified a physiologically based pharmacokinetic (PBPK) model for mirabegron in healthy subjects using the Simcyp Simulator by incorporating data on the inhibitory effect on cytochrome P450 (CYP) 2D6 and a multi‐elimination pathway mediated by CYP3A4, uridine 5′‐diphosphate‐glucuronosyltransferase (UGT) 2B7 and butyrylcholinesterase (BChE). The aim of this study was to use this PBPK model to assess the magnitude of drug–drug interactions (DDIs) in an elderly population with severe renal impairment (sRI), which has not been evaluated in clinical trials. We first determined the system parameters, and meta‐analyses of literature data suggested that the abundance of UGT2B7 and the BChE activity in an elderly population with sRI was almost equivalent to and 20% lower than that in healthy young subjects, respectively. Other parameters, such as the CYP3A4 abundance, for an sRI population were used according to those built into the Simcyp Simulator. Second, we confirmed that the PBPK model reproduced the plasma concentration–time profile for mirabegron in an sRI population (simulated area under the plasma concentration–time curve (AUC) was within 1.5‐times that of the observed value). Finally, we applied the PBPK model to simulate DDIs in an sRI population. The PBPK model predicted that the AUC for mirabegron with itraconazole (a CYP3A4 inhibitor) was 4.12‐times that in healthy elderly subjects administered mirabegron alone, and predicted that the proportional change in AUC for desipramine (a CYP2D6 substrate) with mirabegron was greater than that in healthy subjects. In conclusion, the PBPK model was verified for the purpose of DDI assessment in an elderly population with sRI.