bluuebunny/crossref_metadata_2025 huggingface dataset:
In‐situ structural characterizations of electrochemical intercalation of graphite compounds
Authors: Li Na , Su Dong
Published: November 2019

Graphite carbon has been successfully used for the anode materials of secondary ion batteries due to its capability of accommodating ions between graphite layers. The intercalation dynamics intrinsically determine the performance of the batteries. In this review, we summarize recent research progresses of structural characterizations on graphite intercalation in electrochemical devices, especially on the in‐situ study on the intercalations of Li/Na/K ions, and other anions, or solvents. These techniques, including X‐ray, electron microscopy, Raman, neutron scattering, nuclear magnetic resonance, and optical microscopy provide direct information of the reaction dynamics and help to understand the factors affecting the electrochemical performances of metallic ion batteries.
Dialkylterphenyl Phosphine‐Based Palladium Precatalysts for Efficient Aryl Amination of N‐Nucleophiles
Authors: Rama Raquel J. , Maya Celia , Nicasio M. Carmen
Published: November 2019

A series of 2‐aminobiphenyl palladacycles supported by dialkylterphenyl phosphines, PR2Ar′ (R=Me, Et, iPr, Cyp (cyclopentyl), Ar′=ArDipp2, ArXyl2f, Dipp (2,6‐C6H3‐(2,6‐C6H3‐(CHMe2)2)2), Xyl=xylyl) have been prepared and structurally characterized. Neutral palladacycles were obtained with less bulky terphenyl phosphines (i.e., Me and Et substituents) whereas the largest phosphines provided cationic palladacycles in which the phosphines adopted a bidentate hemilabile k1‐P,η1‐Carene coordination mode. The influence of the ligand structure on the catalytic performance of these Pd precatalysts was evaluated in aryl amination reactions. Cationic complexes bearing the phosphines PiPr2ArXyl2 and PCyp2ArXyl2 were the most active of the series. These precatalysts have demonstrated a high versatility and efficiency in the coupling of a variety of nitrogen nucleophiles, including secondary amines, alkyl amines, anilines, and indoles, with electronically deactivated and ortho‐substituted aryl chlorides at low catalyst loadings (0.25–0.75 mol % Pd) and without excess ligand.
Time‐Resolved Dynamics of Struvite Crystallization: Insights from the Macroscopic to Molecular Scale
Authors: Kim Doyoung , Olympiou Chara , McCoy Colin P. , Irwin Nicola J. , Rimer Jeffrey D.
Published: November 2019

The crystallization of magnesium ammonium phosphate hexahydrate (struvite) often occurs under conditions of fluid flow, yet the dynamics of struvite growth under these relevant environments has not been previously reported. In this study, we use a microfluidic device to evaluate the anisotropic growth of struvite crystals at variable flow rates and solution supersaturation. We show that bulk crystallization under quiescent conditions yields irreproducible data owing to the propensity of struvite to adopt defects in its crystal lattice, as well as fluctuations in pH that markedly impact crystal growth rates. Studies in microfluidic channels allow for time‐resolved analysis of seeded growth along all three principle crystallographic directions and under highly controlled environments. After having first identified flow rates that differentiate diffusion and reaction limited growth regimes, we operated solely in the latter regime to extract the kinetic rates of struvite growth along the [100], [010], and [001] directions. In situ atomic force microscopy was used to obtain molecular level details of surface growth mechanisms. Our findings reveal a classical pathway of crystallization by monomer addition with the expected transition from growth by screw dislocations at low supersaturation to that of two‐dimensional layer generation and spreading at high supersaturation. Collectively, these studies present a platform for assessing struvite crystallization under flow conditions and demonstrate how this approach is superior to measurements under quiescent conditions.
Recent Advances of the Halogen–Zinc Exchange Reaction
Authors: Balkenhohl Moritz , Knochel Paul
Published: November 2019

For the preparation of zinc organometallics bearing highly sensitive functional groups such as ketones, aldehydes or nitro groups, especially mild halogen–zinc exchange reagents have proven to be of great potential. In this Minireview, the latest research in the area of the halogen–zinc exchange reaction is reported, with a special focus lying on novel dialkylzinc reagents complexed with lithium alkoxides. Additionally, the preparation and application of organofluorine zinc reagents and transition‐metal‐catalyzed halogen–zinc exchange reactions are reviewed.
Metal‐Metal Cooperation in Dinucleating Complexes Involving Late Transition Metals Directed towards Organic Catalysis
Authors: Xiong Ni , Zhang Guoxiang , Sun Xiaolong , Zeng Rong
Published: November 2019

Cooperatively bimetallic organic catalysis, coupling actions of two metal centers in a catalytic organic transformation via co‐activation of a single molecule or synergistic activation of two molecules, has witnessed rapid development in the last decades. This cooperative reacting mode creates new catalytic platforms to facilitate the characterization of bimetallic reaction pathways, offers remarkable improvements to some well‐established reactions, or exhibit unprecedented reactivity. Herein, we demonstrate perspectives of some significant contributions in the field of cooperatively bimetallic organic catalysis using dinucleating complexes with late transition metals. Based on different activation modes for the catalysis, the major advances are classified into: (1) bimetallic co‐activation of small molecules; (2) bimetallic co‐activation of single molecules; (3) bimetallic dual‐activation of two molecules. The mechanisms are also discussed to facilitate the understanding of the way of the metal‐metal cooperation involved in the catalytic cycles.
Enhanced Ethanol Production from CO2 Electroreduction at Micropores in Nitrogen‐Doped Mesoporous Carbon
Authors: Song Yanfang , Wang Shibin , Chen Wei , Li Shenggang , Feng Guanghui , Wei Wei , Sun Yuhan
Published: November 2019

Efficient formation of valuable multicarbon products in CO2 electrochemical reduction is challenging, owing to the difficulty of C−C coupling. Medium micropores embedded in the channel walls of nitrogen‐doped ordered mesoporous carbon are found to capably promote ethanol production from CO2 electroreduction. By scaling up the medium micropore content, the yield of ethanol is increased to 2.3 mmol gcat−1 h−1, far outperforming previously reported state‐of‐the‐art electrocatalysts. The intrinsically higher activity is attributed to the desolvation effect induced by the medium micropores, facilitating the coupling reaction of C1 intermediates to form ethanol.
Benzoquinone‐ and Naphthoquinone‐Bearing Polymers Synthesized by Ring‐Opening Metathesis Polymerization as Cathode Materials for Lithium‐Ion Batteries
Authors: Shi Yeqing , Sun Pengfei , Yang Jixing , Xu Yunhua
Published: November 2019

Organic electrode materials have attracted great interest for next‐generation lithium‐ion batteries owing to their merits of low cost, resource sustainability, and environmental friendliness. Dissolution in organic electrolyte is one of critical factors that limit their development, and constructing corresponding polymers is an effective way to prevent it. Herein, the synthesis of benzoquinone‐ and naphthoquinone‐bearing polymers by ring‐opening metathesis polymerization of monomers with an exo‐type four‐membered ring between polymerizable norbornene and redox‐active quinone units is reported. They exhibit significantly reduced solubility and clearly enhanced electrochemical performance. In particular, a high capacity (189.7 mAh g−1 at 0.1 C, 1 C=216.1 mA g−1), stable cycling (75.6 % capacity retention after 500 cycles at 2 C), and good rate capability (retaining 80.4 % from 0.1 to 2 C) were obtained for the naphthoquinone‐bearing polymer, which stand out among naphthoquinone‐bearing polymer electrode materials. This work offers rational molecular design and a new polymerization strategy to construct high‐performance polymer electrode materials.
Safeguarding Participants in Psychiatric Genetic Research: Perspectives of Key Stakeholder Groups
Authors: Rostami Maryam , Dunn Laura B. , Kim Jane Paik , Roberts Laura Weiss
Published: November 2019

Public trust in research depends on implementation of research protections. Genetic and psychiatric research may elicit “exceptionalism,” the belief that these types of research deserve special protections. Genetic information has been viewed as different from other health information. Psychiatric research has been scrutinized based on concerns about the impact of psychiatric illness on individuals’ abilities to make decisions. This study compared four stakeholder groups’ attitudes toward research safeguards. Psychiatric genetic researchers and institutional review board chairs received structured surveys. Individuals with mental illness and family members participated in semistructured interviews. Paired sample t‐tests were used to compare mean ratings of importance of safeguard procedures for genetic versus nongenetic research on physical versus mental illnesses. All groups provided higher ratings for the importance of safeguards for genetic research and for mental illness. Individuals with mental illness and family members rated the importance of safeguards more highly than researchers and chairs did. Results of generalized linear models showed significant effects of gender and ethnicity.
Winter emissions of CO2, CH4, and N2O from temperate agricultural dams: fluxes, sources, and processes
Authors: Ollivier Quinn R. , Maher Damien T. , Pitfield Chris , Macreadie Peter I.
Published: November 2019

Through the microbial breakdown of organic matter and production of greenhouse gases (GHGs), small agricultural dams or ponds have recently been shown to make a relatively large contribution to freshwater ecosystem carbon cycling. However, current estimates of their total carbon dioxide‐equivalent (CO2‐e) emissions lack inclusion of both seasonal and diel fluctuations. In addition, the atmospheric emissions of nitrous oxide from these often eutrophic systems have yet to be established. Here, we quantified the diffusive winter emissions of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) from 12 small agricultural dams within southeast Australia over a 24‐h period. The winter CO2‐e emissions of small agricultural water bodies were ~92% lower than previous summer estimates, at 1.02 g·m−2·d−1, while N2O contributed just 3.2% of this total. We also show that diel cycles do not significantly affect winter CO2, CH4, or N2O emission rates, and we discuss the likely carbon sources to these systems, through analyses of stable carbon isotopes (δ13C). The results from this study fill key gaps in our knowledge of agricultural dam GHG production and global atmospheric emissions, aiding their inclusion into future GHG budgets.
Design, Synthesis, and Structure of Copper Dithione Complexes: Redox‐Dependent Charge Transfer
Authors: Colston Kyle J. , Dille Sara A. , Mogesa Benjamin , Astashkin Andrei V. , Brant Jacilynn A. , Zeller Matthias , Basu Partha
Published: November 2019

Redox‐active ligands impart versatility in transition metal complexes, which are attractive for photosensitizers, dye sensitized solar cells, photothermal therapy, etc. Dithiolene (Dt) ligands can transition between fully reduced and fully oxidized states. Herein, we report the syntheses, characterization, crystal structures and electronic properties of four [Cu(R2Dt0)2]+/2+ (R = Me, iPr) complexes, [Cu(iPr2Dt0)2][PF6] (1a), [Cu(iPr2Dt0)2][PF6]2 (1b), and [Cu(Me2Dt0)2][PF6] (2a), [Cu(Me2Dt0)2][PF6]2 (2b), where iPr2Dt0 = N,N′‐diisopropyl‐1,2‐piperazine dithione and Me2Dt0 = N,N′‐dimethyl‐1,2‐piperazine dithione. In addition, the molecular structure of [Cu(iPr2Dt0)2][BF4]2(1c) is also reported. Complexes 1a and 2a crystallized in the triclinic, P1 space group, and 1c crystallized in the monoclinic crystal system, space group C2/c. The single‐crystal X‐ray diffraction measurements show that the Cu(I) complexes have a distorted tetrahedral geometry, whereas the Cu(II) complex exhibits a true square‐planar geometry. Cu(I) complexes exhibit a low energy charge‐transfer band (450–650 nm), which are not observed in Cu(II) complexes. Electrochemical studies of these complexes show both ligand‐ and metal‐based redox couples.
A Novel Bioelectrochemical Sensor Based on Immobilized Urease on the Surface of Nickel Oxide Nanoparticle and Polypyrrole Composite Modified Pt Electrode
Authors: Hosseinian Maliheh , Darzi Ghasem Najafpour , Rahimpour Ahmad
Published: November 2019

Nickel oxide nanoparticle (NiO−NP) and polypyrrole (PPy) composite were deposited on a Pt electrode for fabrication of a urea biosensor. To develop the sensor, a thin film of PPy−NiO composite was deposited on a Pt substrate that serves as a matrix for the immobilization of enzyme. Urease was immobilized on the surface of Pt/PPy−NiO by a physical adsorption. The response of the fabricated electrode (Pt/PPy−NiO/Urs) towards urea was analyzed by chronoamperometry and cyclic voltammetry (CV) techniques. Electrochemical response of the bio‐electrode was significantly enhanced. This is due to electron transfer between Ni2+ and Ni3+ as the electro‐catalytic group and the reaction between polypyrrole and the urease‐liberated ammonium. The fabricated electrode showed reliable and demonstrated perfectly linear response (0.7–26.7 mM of urea concentration, R2= 0.993), with high sensitivity (0.153 mA mM−1 cm−2), low detection of limit (1.6 μM), long stability (10 weeks), and low response time (∼5 s). The developed biosensor was highly selective and obtained data were repeatable and reproduced using PPy‐NiO composite loaded with immobilized urease as urea biosensors.
Smartphone‐coupled Electrochemical Analysis of Cellular Superoxide Anions Based on Mnx(PO4)y Monolayer Modified Porous Carbon
Authors: Cai Xuan , Gao Qianmei , Zuo Shaohua , Zhao Hongli , Lan Minbo
Published: November 2019

Here we established a palm‐sized electrochemical sensor for the determination of cell‐released superoxide anions (O2.−) based on a self‐developed portable potentiostat (xenSTAT) which can perform fast analysis with visual real‐time data and customizable parameters. The xenSTAT was equipped with Bluetooth and USB interfaces, thus being able to be connected with both smartphones and computers for electrochemical analysis. A novel Nanozyme based on Mnx(PO4)y monolayer modified porous carbon cubic was synthesized and used as functional material on the surface of working electrode. By using cyclic voltammetry (CV) and chronoamperometry, xenSTAT was demonstrated to exhibit satisfying sensitivity and excellent stability for real‐time monitoring of O2.− released from cancer cells. With decreased cost, customizable development, small size and convenient usage, the xenSTAT described in this work could promote the commercialization and widespread of in‐house built electrochemical sensors for the monitoring of O2.− in the future.
Effects of chitosan‐based coatings on storage quality of Chinese shrimp
Authors: Zhang Zhen , Xia Guanghui , Yang Qiang , Fan Xinwen , Lyu Shuxia
Published: November 2019

We investigated the effects of chitosan‐based coatings on the preservation quality of refrigerated Chinese shrimp for 12 days. Samples of Chinese shrimp were subjected to three different coating treatments, namely chitosan (CH), chitosan and ε‐polylysine (CH + ε‐PL), chitosan combined with ε‐polylysine and carrageenan (CH + ε‐PL + CA), and compared with a control. The bacteriological characteristics [total viable count (TVC)], chemical indexes including pH, thiobarbituric acid (TBA) value, K‐value, and total volatile basic nitrogen (TVB‐N), texture (hardness, chewiness, and elasticity), and sensory changes were assessed. The increases in TVC, pH, TBA, K‐value, and TVB‐N were observed to be delayed by preservation treatments, and the textural and sensory characteristics indicated that the treated shrimp were preserved more effectively than the control. Treatment with chitosan combined with ε‐polylysine and carrageenan was the most effective preservation method than treatment with chitosan alone or chitosan and ε‐polylysine; the shelf life was also prolonged. Therefore, treatment with chitosan combined with ε‐polylysine and carrageenan is proposed as a potential method for shelf life extension of Chinese shrimp for refrigerated storage.
Limited contribution of astroglial gap junction coupling to buffering of extracellular K+ in CA1 stratum radiatum
Authors: Breithausen Björn , Kautzmann Steffen , Boehlen Anne , Steinhäuser Christian , Henneberger Christian
Published: November 2019

Astrocytes form large networks, in which individual cells are connected via gap junctions. It is thought that this astroglial gap junction coupling contributes to the buffering of extracellular K+ increases. However, it is largely unknown how the control of extracellular K+ by astroglial gap junction coupling depends on the underlying activity patterns and on the magnitude of extracellular K+ increases. We explored this dependency in acute hippocampal slices (CA1, stratum radiatum) by direct K+‐sensitive microelectrode recordings and acute pharmacological inhibition of gap junctions. K+ transients evoked by synaptic and axonal activity were largely unaffected by acute astroglial uncoupling in slices obtained from young and adult rats. Iontophoretic K+‐application enabled us to generate K+ gradients with defined spatial properties and magnitude. By varying the K+‐iontophoresis position and protocol, we found that acute pharmacological uncoupling increases the amplitude of K+ transients once their initial amplitude exceeded ~10 mM. Our experiments demonstrate that the contribution of gap junction coupling to buffering of extracellular K+ gradients is limited to large and localized K+ increases.
Curved multiplanar reformatting provides improved visualization of hippocampal anatomy
Authors: Gross Donald William , Misaghi Ehsan , Steve Trevor A. , Wilman Alan H. , Beaulieu Christian
Published: November 2019

There is a growing body of literature studying changes in hippocampal subfields in a variety of different neurological conditions, but this work has mainly focused on the hippocampal body given challenges in visualization of hippocampal anatomy in the head and tail when sectioned in the typical coronal image plane. Curved multiplanar reformatting (CMPR) is an image reconstruction method that can improve visualization of complex three‐dimensional structures. The objective of this study was to determine whether CMPR could facilitate visualization of the human hippocampal anatomy along the entire caudal–rostral axis. CMPR was applied to high‐resolution magnetic resonance imaging acquired ex vivo on four cadaveric hippocampal specimens at 4.7 T (T2‐weighted, 0.2 × 0.2 × 0.5 mm3). CMPR provided clear visualization of the classic “interlocking C” appearance of the dentate gyrus and cornu ammonis along the entire caudal–rostral axis including the head and tail, which otherwise show complex anatomy on the standard coronal slices. CMPR facilitated visualization of hippocampal anatomy providing the impetus to develop simplified approaches to delineate subfields along the entire hippocampus including the usually neglected head and tail.
Associations between sleep and episodic memory updating
Authors: Bryant Natalie B. , Nadel Lynn , Gómez Rebecca L.
Published: November 2019

Prior research shows that contextual reminders can reactivate hippocampal links to previously consolidated memories, rendering them susceptible to being updated with new information which then is reconsolidated. Studies implicate sleep in the reconsolidation of reactivated memories, but it is unknown what role sleep plays in updating of a previously consolidated trace with new information. We tracked participants' sleep during an episodic reconsolidation paradigm, first with actigraphy (Experiment 1) then with polysomnography (Experiment 2). Our paradigm involved two learning sessions and a retrieval session, each separated by 48 hr. We reminded participants of the first learning experience immediately prior to the second, which led them to update the earlier memory with elements of the later experience. In Experiment 1, less sleep after Session 1 and more sleep after Session 2 are associated with increased updating. In Experiment 2, N2 sleep spindles (SSs) after the reminder and new learning are associated with more updating, but primarily when spindle activity after Session 1 is low. Thus, total sleep time and N2 SSs contribute to sleep‐dependent updating of episodic memory. This outcome is consistent with other work connecting SS activity to the integration of novel information into existing knowledge structures, extended here with the study of how variations in sleep over successive nights contribute to this process. We discuss some possible roles of spindles in the decontextualization of hippocampal memory over time. Although much work addresses the role of sleep in the consolidation of new memories, this work uniquely addresses the contribution of sleep to the updating of a previously consolidated trace with new information.
Assessing vertical diffusion in a stratified lake using a three‐dimensional hydrodynamic model
Authors: Dong Fei , Mi Chenxi , Hupfer Michael , Lindenschmidt Karl‐Erich , Peng Wenqi , Liu Xiaobo , Rinke Karsten
Published: November 2019

Vertical turbulent diffusivity (Kz), which can be estimated from water temperature, is a key factor in the evolution of water quality in lentic waters. In this study, we analysed the capability of a three‐dimensional hydrodynamic model (EFDC) to capture water temperature and vertical diffusivity in Lake Arendsee in the Northern German plain. Of particular interest to us is to evaluate the model performance for capturing the diffusion minimum within the metalimnion and analyse the response of the metalimnetic Kz to meteorological forcing, namely changing wind speed and warming. The comparison confirmed that the calibrated model could reproduce both stratification dynamics and vertical diffusion profiles in the lake. The model was also shown to be able to capture the duration and vertical extent of the metalimnetic diffusion minimum. The scenario results illustrate that, compared to air temperature, wind velocity appeared to be the more influential meteorological variable on the vertical exchange within the metalimnion. While increasing wind velocities mostly affected the minimum values of Kz in the metalimnion and thus led to intensified vertical exchange, the reduction of wind velocity mostly affected the depth of minimal Kz, but not its absolute value.
Layer‐by‐layer assembled PLGA nanoparticles carrying miR‐34a cargo inhibit the proliferation and cell cycle progression of triple‐negative breast cancer cells
Authors: Kapadia Chintan H. , Ioele Stephen A. , Day Emily S.
Published: November 2019

Triple‐negative breast cancer (TNBC) accounts for 15–25% of diagnosed breast cancers, and its lack of a clinically defined therapeutic target has caused patients to suffer from earlier relapse and higher mortality rates than patients with other breast cancer subtypes. MicroRNAs (miRNAs) are small non‐coding RNAs that regulate the expression of multiple genes through RNA interference to maintain normal tissue function. The tumor suppressor miR‐34a is downregulated in TNBC, and its loss‐of‐expression correlates with worse disease outcomes. Therefore, delivering miR‐34a mimics into TNBC cells is a promising strategy to combat disease progression. To achieve this goal, we synthesized layer‐by‐layer assembled nanoparticles (LbL NPs) comprised of spherical poly(lactic‐co‐glycolic acid) cores surrounded by alternating layers of poly‐L‐lysine (PLL) and miR‐34a. TNBC cells internalized these LbL NPs to a greater extent than polyplexes comprised of PLL and miRNA, and confocal microscopy showed that LbL NPs delivered a substantial fraction of miR‐34a cargo into the cytosol. This yielded robust suppression of the miR‐34a target genes CCND‐1, Notch‐1, Bcl‐2, Survivin, and MDR‐1, which reduced TNBC cell proliferation and induced cell cycle arrest. These data validate that miR‐34a delivery can impair TNBC cell function and support continued investigation of this platform for treatment of TNBC.
Bone regeneration using β‐tricalcium phosphate (β‐TCP) block with interconnected pores made by setting reaction of β‐TCP granules
Authors: Putri Tansza S. , Hayashi Koichiro , Ishikawa Kunio
Published: November 2019

We fabricated an interconnected dual porous β‐tricalcium phosphate (β‐TCP) block via a setting reaction of β‐TCP granules. This β‐TCP block was unique because it exhibits a fully interconnected macroporous structure with micropores in the walls surrounding macropores and a roughened surface. The porosity and diametral tensile strength of the resulting product were 58.1 ± 1.7% and 1.4 ± 0.2 MPa, respectively. Rabbit distal femur bone defects were reconstructed using the porous β‐TCP block and the efficacy of the porous β‐TCP block as an artificial bone substitute was evaluated histomorphometrically. For a dense β‐TCP control, 4 weeks following implantation, only 0.2 ± 0.1% of the β‐TCP was resorbed, and the amount of newly formed bone was limited (0.1 ± 0.1%), whereas when the defect was reconstructed with porous β‐TCP, 9.2 ± 3.1% was resorbed, and the amount of new bone was 18.9 ± 5.5%. This represents an approximately 50‐fold enhancement in resorption and a 200‐fold increase in bone formation for our porous β‐TCP block. Therefore, interconnected dual porous β‐TCP made via β‐TCP granule setting has good potential as an artificial bone substitute.
Effect of Advanced Glycation End-Products (AGE) Lowering Drug ALT-711 on Biochemical, Vascular, and Bone Parameters in a Rat Model of CKD-MBD
Authors: Chen Neal X , Srinivasan Shruthi , O'Neill Kalisha , Nickolas Thomas L , Wallace Joseph M , Allen Matthew R , Metzger Corinne E , Creecy Amy , Avin Keith G , Moe Sharon M
Published: November 2019

Chronic kidney disease–mineral bone disorder (CKD-MBD) is a systemic disorder that affects blood measures of bone and mineral homeostasis, vascular calcification, and bone. We hypothesized that the accumulation of advanced glycation end-products (AGEs) in CKD may be responsible for the vascular and bone pathologies via alteration of collagen. We treated a naturally occurring model of CKD-MBD, the Cy/+ rat, with a normal and high dose of the AGE crosslink breaker alagebrium (ALT-711), or with calcium in the drinking water to mimic calcium phosphate binders for 10 weeks. These animals were compared to normal (NL) untreated animals. The results showed that CKD animals, compared to normal animals, had elevated blood urea nitrogen (BUN), PTH, FGF23 and phosphorus. Treatment with ALT-711 had no effect on kidney function or PTH, but 3 mg/kg lowered FGF23 whereas calcium lowered PTH. Vascular calcification of the aorta assessed biochemically was increased in CKD animals compared to NL, and decreased by the normal, but not high dose of ALT-711, with parallel decreases in left ventricular hypertrophy. ALT-711 (3 mg/kg) did not alter aorta AGE content, but reduced aorta expression of receptor for advanced glycation end products (RAGE) and NADPH oxidase 2 (NOX2), suggesting effects related to decreased oxidative stress at the cellular level. The elevated total bone AGE was decreased by 3 mg/kg ALT-711 and both bone AGE and cortical porosity were decreased by calcium treatment, but only calcium improved bone properties. In summary, treatment of CKD-MBD with an AGE breaker ALT-711, decreased FGF23, reduced aorta calcification, and reduced total bone AGE without improvement of bone mechanics. These results suggest little effect of ALT-711 on collagen, but potential cellular effects. The data also highlights the need to better measure specific types of AGE proteins at the tissue level in order to fully elucidate the impact of AGEs on CKD-MBD. © 2019 American Society for Bone and Mineral Research.
Simulating ion channel activation mechanisms using swarms of trajectories
Authors: Lev Bogdan , Allen Toby W.
Published: November 2019

Atomic‐level studies of protein activity represent a significant challenge as a result of the complexity of conformational changes occurring on wide‐ranging timescales, often greatly exceeding that of even the longest simulations. A prime example is the elucidation of protein allosteric mechanisms, where localized perturbations transmit throughout a large macromolecule to generate a response signal. For example, the conversion of chemical to electrical signals during synaptic neurotransmission in the brain is achieved by specialized membrane proteins called pentameric ligand‐gated ion channels. Here, the binding of a neurotransmitter results in a global conformational change to open an ion‐conducting pore across the nerve cell membrane. X‐ray crystallography has produced static structures of the open and closed states of the proton‐gated GLIC pentameric ligand‐gated ion channel protein, allowing for atomistic simulations that can uncover changes related to activation. We discuss a range of enhanced sampling approaches that could be used to explore activation mechanisms. In particular, we describe recent application of an atomistic string method, based on Roux's “swarms of trajectories” approach, to elucidate the sequence and interdependence of conformational changes during activation. We illustrate how this can be combined with transition analysis and Brownian dynamics to extract thermodynamic and kinetic information, leading to understanding of what controls ion channel function. © 2019 Wiley Periodicals, Inc.
Record Atomistic Simulation of Crystalline Silicon: Bridging Microscale Structures and Macroscale Properties
Authors: Hou Chaofeng , Zhang Chenglong , Ge Wei , Wang Lei , Han Lin , Pang Jianmin
Published: November 2019

Based on the molecular dynamics software package CovalentMD 2.0, the fastest molecular dynamics simulation for covalent crystalline silicon with bond‐order potentials has been implemented on the third highest performance supercomputer “Sunway TaihuLight” in the world (before June 2019), and already obtained 16.0 Pflops (1015 floating point operation per second) in double precision for the simulation of crystalline silicon, which is recordly high for rigorous atomistic simulation of covalent materials. The simulations used up to 160,768 64‐core processors, totally nearly 10.3 million cores, to simulate more than 137 billion silicon atoms, where the parallel efficiency is over 80% on the whole machine. The running performance on a single processor reached 15.1% of its theoretical peak at highest. The longitudinal dimension of the simulated system is far beyond the range with scale‐dependent properties, while the lateral dimension significantly exceeds the experimentally measurable range. Our simulation enables virtual experiments on real‐world nanostructured materials and devices for predicting macroscale properties and behaviors from microscale structures directly, bringing about many exciting new possibilities in nanotechnology, information technology, electronics and renewable energies, etc. © 2019 Wiley Periodicals, Inc.
Silencing of long noncoding RNA SRRM2‐AS exerts suppressive effects on angiogenesis in nasopharyngeal carcinoma via activating MYLK‐mediated cGMP‐PKG signaling pathway
Authors: Chen Shaoqing , Lv Linrong , Zhan Zhengyu , Wang Xiaolang , You Zhenyu , Luo Xiao , You Haoyuan
Published: November 2019

Long noncoding RNAs (lncRNAs) play a crucial role in several malignances, involving nasopharyngeal carcinoma (NPC), a heterogeneous disease. This study investigated mechanism of serine/arginine repetitive matrix protein 2‐alternative splicing (SRRM2‐AS) in NPC cell proliferation, differentiation, and angiogenesis. Initially, differentially expressed lncRNAs were screened out via microarray analysis. Vascular endothelial growth factor (VEGF) protein positive rate and microvessel density (MVD) were determined in NPC and adjacent tissues. NPC CNE‐2 cells were treated with a series of vector and small interfering RNA to explore the effect of SRRM2‐AS in NPC. The target relationship between myosin light chain kinase (MYLK) and SRRM2‐AS was verified. Levels of SRRM2‐AS, MYLK, cGMP, PKG, VEGF, PCNA, Ki‐67, B‐cell lymphoma‐2 (Bcl‐2), Bcl‐2‐associated X protein (Bax), and Caspase 3 were determined after transfection. Finally, the effect of SRRM2‐AS on cell proliferation, colony formation, angiogenesis, cell cycle, and apoptosis in NPC was evaluated. SRRM2‐AS was highly expressed and MYLK was poorly expressed in NPC tissues. VEGF protein positive rate and MVD were elevated in NPC tissues. MYLK was confirmed to be a target gene of SRRM2‐AS. Silencing of SRRM2‐AS elevated levels of MYLK, cGMP, PKG, Bax, and Caspase 3, but decreased levels of VEGF, PCNA, Ki‐67, and Bcl‐2. Especially, silencing of SRRM2‐AS suppressed cell proliferation, colony formation and angiogenesis, blocked cell cycle, and enhanced cell apoptosis in NPC. Our results suggested that silencing of SRRM2‐AS protected against angiogenesis of NPC cells by upregulating MYLK and activating the cGMP‐PKG signaling pathway, which provides a new target for NPC treatment.
Fair trade as a social enterprise: Oversold, misunderstood or unethical?
Authors: Mohan Sushil , Upadhyay Arvind , Daskalakis Nikolaos , Durham Ridhima
Published: November 2019

Although the concept of Fair Trade blends with the concept of “social enterprises,” but a critical examination of the theory and practice of Fair Trade shows that considering Fair Trade as an obvious example of “social enterprise” would mean a dilution of the social context of “social enterprises.”
Treatment of colorectal cancer in Sub‐Saharan Africa: Results from a prospective Nigerian hospital registry
Authors: Sharma Avinash , Alatise Olusegun I. , Adisa Adewale O. , Arowolo Olukayode A. , Olasehinde Olalekan , Famurewa Olusola C. , Omisore Adeleye D. , Komolafe A. O. , Olaofe O. , Katung Aba I. , Ibikunle Ayoola D. , Egberongbe Ayoola A. , Olatoke Samuel A. , Agodirin S. O. , Adesiyun A. O. , Adeyeye Ademola , Ibrahim K. , Kolawole O. A. , Idris O. L. , Adejumobi M. O. , Ajayi Adebowale I. , Olakanmi Akinwumi O. , Constable Jeremy C. , Seier Ken , Gonen Mithat , Brennan Murray F. , Kingham T. Peter
Published: November 2019

Background

Colorectal cancer (CRC) is the third most common cancer worldwide. Mortality for CRC is improving in high income countries, but in low and middle income countries, rates of disease and death from disease are rising. In Sub‐Saharan Africa, the ratio of CRC mortality to incidence is the highest in the world. This study investigated the nature of CRC treatment currently being offered and received in Nigeria.

Methods

Between April 2013 and October 2017, a prospective study of consecutively diagnosed cases of CRC was conducted. Patient demographics, clinical features, and treatment recommended and received was recorded for each case. Patients were followed during the study period every 3 months or until death.

Results

Three hundred patients were included in our analysis. Seventy‐one percent of patients received a recommended surgical operation. Of those that didn't undergo surgery as recommended, 37% cited cost as the main reason, 30% declined due to personal reasons, and less than 5% absconded or were lost to follow up. Approximately half of patients (50.5%) received a chemotherapy regimen when it was recommended, and 4.1% received radiotherapy when this was advised as optimal treatment. With therapy, the median overall survival for patients diagnosed with stage III and stage IV CRC was 24 and 10.5 months respectively. Overall, we found significantly better median survival for patients that received the recommended treatment (25 vs 7 months; P < .01).

Conclusions

A number of patients were unable to receive the recommended treatment, reflecting some of the burden of untreated CRC in the region. Receiving the recommended treatment was associated with a significant difference in outcome. Improved healthcare financing, literacy, training, access, and a better understanding of tumor biology will be necessary to address this discrepancy.
Best practices for emergency surgical airway: A systematic review
Authors: DeVore Elliana K. , Redmann Andrew , Howell Rebecca , Khosla Sid
Published: November 2019

Objective

In the case of an emergency surgical airway, current guidelines state that surgical cricothyrotomy is preferable to tracheotomy. However, complications associated with emergency cricothyrotomy may be more frequent and severe. We systematically reviewed the English literature on emergency surgical airway to elicit best practices.

Methods

PubMed, Embase, MEDLINE, and the Cochrane Library were searched from inception to January 2019 for studies reporting emergency cricothyrotomy and tracheotomy outcomes. All English‐language retrospective analyses, systematic reviews, and meta‐analyses were included. Case reports were excluded, as well as studies with pediatric, nonhuman, or nonliving subjects.

Results

We identified 783 articles, and 20 met inclusion criteria. Thirteen evaluated emergency cricothyrotomy and included 1,219 patients (mean age = 39.8 years); 4 evaluated emergency tracheotomy and included 342 patients (mean age = 46.0 years); 2 evaluated both procedures. The rate of complications with both cricothyrotomy and tracheotomy was comparable. The most frequent early complications were failure to obtain an airway (1.6%) and hemorrhage (5.6%) for cricothyrotomy and tracheotomy, respectively. Airway stenosis was the most common long‐term complication, occurring at low rates in both procedures (0.22–7.0%).

Conclusions

Complications associated with emergency cricothyrotomy may not occur as frequently as presumed. Tracheotomy is an effective means of securing the airway in an emergent setting, with similar risk for intraoperative and postoperative complications compared to cricothyrotomy. Ultimately, management should depend on clinician experience and patient characteristics.

Level of Evidence

IV
Response of the sea‐ice diatomFragilariopsis cylindrusto simulated polar night darkness and return to light
Authors: Morin Philippe‐Israël , Lacour Thomas , Grondin Pierre‐Luc , Bruyant Flavienne , Ferland Joannie , Forget Marie‐Hélène , Massicotte Philippe , Donaher Natalie , Campbell Douglas A. , Lavaud Johann , Babin Marcel
Published: November 2019

Arctic photoautotrophic communities must survive through polar night darkness until light returns in spring. We tracked changes in the cellular resource allocations and functional capacities of a polar sea‐ice diatom,Fragilariopsis cylindrus, to understand acclimation processes in both darkness and during the subsequent return to light. We measured parameters at specific time‐points over 3 months of darkness, and then over 6 d after a return to light. Measured parameters included cell number and size, cellular carbon and nitrogen quotas, lipid and pigment contents, concentration of key proteins of the photosynthetic system, photosynthetic parameters based on both variable fluorescence and carbon assimilation, and the level of nonphotochemical quenching. A stable functional state was reached within a few days after the transition to dark and was then maintained throughout 3 months of darkness. The dark period resulted in a decrease of lipid droplet cell quota (−6%), chlorophyllacell quota (−41%) and the maximum carbon fixation rate per cell (−98%). Return to light after 1.5 months of darkness resulted in a strong induction of nonphotochemical quenching of excitation and a fast recovery of the maximum carbon fixation rate within 1 d, followed by a rapid increase in the cell number. Return to light after 3 months of darkness showed an increase of mortality or a profound downregulation induced over longer periods of darkness.
Autophagy modulators for the treatment of oral and esophageal squamous cell carcinomas
Authors: Khan Tuhina , Relitti Nicola , Brindisi Margherita , Magnano Stefania , Zisterer Daniela , Gemma Sandra , Butini Stefania , Campiani Giuseppe
Published: November 2019

Oral squamous cell carcinomas (OSCC) and esophageal squamous cell carcinomas (ESCC) exhibit a survival rate of less than 60% and 40%, respectively. Late‐stage diagnosis and lack of effective treatment strategies make both OSCC and ESCC a significant health burden. Autophagy, a lysosome‐dependent catabolic process, involves the degradation of intracellular components to maintain cell homeostasis. Targeting autophagy has been highlighted as a feasible therapeutic strategy with clinical utility in cancer treatment, although its associated regulatory mechanisms remain elusive. The detection of relevant biomarkers in biological fluids has been anticipated to facilitate early diagnosis and/or prognosis for these tumors. In this context, recent studies have indicated the presence of specific proteins and small RNAs, detectable in circulating plasma and serum, as biomarkers. Interestingly, the interplay between biomarkers (eg, exosomal microRNAs) and autophagic processes could be exploited in the quest for targeted and more effective therapies for OSCC and ESCC. In this review, we give an overview of the available biomarkers and innovative targeted therapeutic strategies, including the application of autophagy modulators in OSCC and ESCC. Additionally, we provide a viewpoint on the state of the art and on future therapeutic perspectives combining the early detection of relevant biomarkers with drug discovery for the treatment of OSCC and ESCC.
Energy decay and control for a system of strings elastically connected in parallel
Authors: Nunes Ruikson S.O. , Bastos Waldemar D. , Pitot João Manoel S.
Published: November 2019

In the present paper, we study energy decay and exact boundary controllability for a system of n one‐dimensional linear wave equations coupled in parallel. The control obtained is a square integrable of the Neuman type for initial data with finite energy. The controllability time is near optimal value. We treat the case of control in the whole boundary and also in part of it.
Hopf bifurcation and the centers on center manifold for a class of three‐dimensional Circuit system
Authors: Huang Wentao , Wang Qinlong , Chen Aiyong
Published: November 2019

In this paper, Hopf bifurcation and center problem for a generic three‐dimensional Chua's circuit system are studied. Applying the formal series method of computing singular point quantities to investigate the two cases of the generic circuit system, we find necessary conditions for the existence of centers on a local center manifold for the systems, then Darboux method is applied to show the sufficiency. Further, we determine the maximum number of limit cycles that can bifurcate from the corresponding equilibrium via Hopf bifurcation.
On the use of surfaces of section in the N‐body ring problem
Authors: Navarro Juan F. , Martínez–Belda M.C.
Published: November 2019

In the N‐body ring problem, we investigate the motion of a massless body interacting with N bodies of equal masses at the vertices of a regular polygon that rotates around a central mass. In this paper, we analyze the use of different surfaces of section in the numerical exploration of the escape in the N‐body ring problem in order to get some conclusions about the geometry of the basins of escape in the corresponding configuration spaces.
Clinical implementation and commissioning of the MedAustron Particle Therapy Accelerator for non‐isocentric scanned proton beam treatments
Authors: Grevillot Loïc , Osorio Moreno Jhonnatan , Letellier Virgile , Dreindl Ralf , Elia Alessio , Fuchs Hermann , Carlino Antonio , Kragl Gabriele , Palmans Hugo , Vatnitsky Stanislav , Stock Markus
Published: November 2019

Purpose

This paper describes the clinical implementation and medical commissioning of the MedAustron Particle Therapy Accelerator (MAPTA) for non‐isocentric scanned proton beam treatments.

Methods

Medical physics involvement during technical commissioning work is presented. Acceptance testing procedures, including advanced measurement methods of intra‐spill beam variations, are defined. Beam monitor calibration using two independent methods based on a dose‐area product formalism is described. Emphasis is given to the medical commissioning work and the specificities related to non‐isocentric irradiation, since a key feature of MedAustron is the routine delivery of non‐isocentric scanned proton beam treatments.

Results

Key commissioning results and beam stability trend lines for more than 2 yr of clinical operation have been provided. Intra‐spill beam range, size, and position variations were within specifications of 0.3 mm, 15%, and 0.5 mm, respectively. The agreement between two independent beam monitor calibration methods was better than 1.0%. Non‐isocentric treatment delivery allowed lateral penumbra reduction of up to about 30%. Daily QA measurements of the beam range, size, position, and dose were always within 1 mm, 10%, 1 mm, and 2% from the baseline data, respectively.

Conclusions

Non‐isocentric treatments have been successfully implemented at MedAustron for routine scanned proton beam therapy using horizontal and vertical fixed beamlines. Up to now every patient was treated in non‐isocentric conditions. The presented methodology to implement a new Scanned Ion Beam Delivery (SIBD) system into clinical routine for proton therapy may serve as a guidance for other centers.
Numerical study on the effect of rigid inclusions on existing railroads
Authors: Wang Dong , Sánchez Marcelo , Briaud Jean‐Louis
Published: November 2019

Railroad track problems have been exacerbated by the continuous increase in freight loads and train traffic. The need to implement soil improvement technique in a relatively short window‐time (ie, to minimize train‐traffic disruption) is a key aspect to be considered when adopting a convenient remedial solution to control settlements in railroads constructed on problematic subgrades. Rigid inclusions are selected in this paper because they are reliable solutions relatively easy to implement. Furthermore, they can be used in different ground conditions and are suitable for short construction times (eg, do not require a curing time, as in grouting methods). Typical (analytical) methods for the design of rigid inclusions are adopted in this paper to define an optimal distribution of piles for the case of existing railroads. The selected layout is then analyzed in detail by means of a 3‐D dynamic finite element simulator using both, elastoplastic and elastic models. The performance of rigid inclusions is studied considering different operational scenarios, with dynamic and static loads, as well as involving subgrades with different plasticity index values. It is found that the predictions from the analytical design methods for rigid inclusion tend to be unconservative when compared against the finite element results. As for the numerical solutions, the most unfavorable stress condition is associated with the dynamic elastoplastic finite element solution. It is estimated that the rigid inclusions will contribute to a reduction in the ground settlements of around 15% to 20%, depending on the subgrade plasticity index.