bluuebunny/crossref_metadata_2025 huggingface dataset:
Direct Power Generation from Low Concentration Coal‐Bed Gas by a Catalyst‐Modified Solid Oxide Fuel Cell
Authors: Chen Huili , Wu Yufang , Yang Guangming , Shi Jing , Zhou Wei , Bai Jianping , Li Si‐Dian , Shao Zongping
Published: March 2018

Clear utilization of low‐concentration coal‐bed gas (LC‐CBG) would save energy, mitigate greenhouse gas emissions, and reduce explosion accidents during a coal‐mining process. In this paper, a novel catalyst Ni/BaO/CeO2 (NBC) is developed for CH4 partial oxidation and is used as an independent catalyst layer of a Ni cermet anode. LC‐CBG with composition of 30 % methane and 70 % air is directly fed to the catalyst‐modified SOFC to generate electricity. Operated on 30 % LC‐CBG, the NBC‐modified cell shows better performance and discharge stability than the conventional cell without the catalyst layer. Gas chromatography (GC) analysis on effluent gases extracted from the operating catalyst‐modified cells also indicates a higher CH4 conversion when the cell is fed with 30 % LC‐CBG than when fed with 3 % H2O‐humidified methane. Post‐mortem microstructures of cell surface were analyzed. The NBC‐modified cell has a potential application for fuels containing low concentration methane and air.
Large Oblate Hemispheroidal Ruthenium Particles Supported on Calcium Amide as Efficient Catalysts for Ammonia Decomposition
Authors: Kishida Kazuhisa , Kitano Masaaki , Inoue Yasunori , Sasase Masato , Nakao Takuya , Tada Tomofumi , Abe Hitoshi , Niwa Yasuhiro , Yokoyama Toshiharu , Hara Michikazu , Hosono Hideo
Published: March 2018

Ammonia decomposition is an important technology for extracting hydrogen from ammonia toward the realization of a hydrogen economy. Herein, it is reported that large oblate hemispheroidal Ru particles on Ca(NH2)2 function as efficient catalysts for ammonia decomposition. The turnover frequency of Ru/Ca(NH2)2 increased by two orders of magnitude when the Ru particle size was increased from 1.5 to 8.4 nm. More than 90 % ammonia decomposition was achieved over Ru/Ca(NH2)2 with large oblate hemispheroidal Ru particles at 360 °C, which is comparable to that of alkali‐promoted Ru catalysts with small Ru particle sizes. XAFS analyses revealed that Ru particles are immobilized on Ca(NH2)2 by Ru−N bonds formed at the metal/support interface, which lead to oblate hemispheroidal Ru particles. Such a strong metal–support interaction in Ru/Ca(NH2)2 is also substantiated by DFT calculations. The high activity of Ru/Ca(NH2)2 with large Ru particles primarily originates from the shape and appropriate size of the Ru particles with a high density of active sites rather than the electron‐donating ability of Ca(NH2)2.
Phenoxyaluminum(salophen) Scaffolds: Synthesis, Electrochemical Properties, and Self‐Assembly at Surfaces of Multifunctional Systems
Authors: Mengozzi Luca , El Garah Mohamed , Gualandi Andrea , Iurlo Matteo , Fiorani Andrea , Ciesielski Artur , Marcaccio Massimo , Paolucci Francesco , Samorì Paolo , Cozzi Pier Giorgio
Published: March 2018

Salophens and Salens are Schiff bases generated through the condensation of two equivalents of salicylaldehyde with either 1,2‐phenylenediamines or aliphatic diamines, respectively. Both ligands have been extensively exploited as key building blocks in coordination chemistry and catalysis. In particular, their metal complexes have been widely used for various catalytical transformations with high yield and selectivity. Through the modification of the phenol unit it is possible to tune the steric hindrance and electronic properties of Salophen and Salen. The introduction of long aliphatic chains in salicylaldehydes can be used to promote their self‐assembly into ordered supramolecular structures on solid surfaces. Herein, we report a novel method towards the facile synthesis of robust and air‐stable [Al(Salophen)] derivatives capable of undergoing spontaneous self‐assembly at the graphite/solution interface forming highly‐ordered nanopatterns. The new synthetic approach relies on the use of [MeAlIII(Salophen)] as a building unit to introduce, via a simple acid/base reaction with functionalized acidic phenol derivatives, selected frameworks integrating multiple functions for efficient surface decoration. STM imaging at the solid/liquid interface made it possible to monitor the formation of ordered supramolecular structures. In addition, the redox properties of the Salophen derivatives functionalized with ferrocene units in solution and on surface were unraveled by cyclic voltammetry. The use of a five‐coordinate aluminum alkyl Salophen precursor enables the tailoring of new Salophen molecules capable of undergoing controlled self‐assembly on HOPG, and thereby it can be exploited to introduce multiple functionalities with subnanometer precision at surfaces, ultimately forming ordered functional patterns.
Cleavage of Two Hydrogen Molecules by Boryldisilenes
Authors: Kosai Tomoyuki , Iwamoto Takeaki
Published: March 2018

Activation of H2 by compounds of main‐group elements has received considerable attention. Herein, we report synthesis of novel monoboryl‐ and monoamino‐substituted disilenes and their characterization by a combination of NMR spectroscopy and single‐crystal X‐ray diffraction analysis. The monoboryldisilene reacts with two molecules of H2 to provide the corresponding trihydridodisilane and hydroborane, whereas the aminodisilene does not react with H2 under the same conditions. The present results together with our previous results indicate that the presence of the boryl‐substituent on the Si=Si double bond is essential to activate the H2 molecule. The low lying empty 2p orbital on the boron atom that interacts effectively with the π*(Si=Si) orbital could be responsible for the activation of H2.
Stable Immobilization of Size‐Controlled Bimetallic Nanoparticles in Photonic Crystal Fiber Microreactor
Authors: Ponce Sebastian , Munoz Macarena , Cubillas Ana M. , Euser Tijmen G. , Zhang Gui‐Rong , Russell Philip St. J. , Wasserscheid Peter , Etzold Bastian J. M.
Published: March 2018

The possibility of immobilizing ex situ‐synthesized colloidal bimetallic nanoparticles (NPs) of well‐defined characteristics inside hollow core photonic crystal fiber (HC‐PCF) microreactors is demonstrated. With the developed method, PtNi clusters remain strongly attached to the fiber core and can be used as active catalysts for the hydrogenation of an azobenzene dye. The study revealed that optical transmission exhibits a size‐dependent behavior, i.e., smaller NPs bring in less optical signal loss. Sufficient light transmission was achieved for all particle sizes. Furthermore, with these catalytic PCF microreactors, kinetic data can be obtained with a much lower amount of precious metals compared to a conventional batch reactor, opening a new pathway for in situ catalyst screening.
Which Dimension of Corporate Social Responsibility is a Value Driver in the Oil and Gas Industry?
Authors: Chowdhury Reza H. , Choi Sungchul , Ennis Simon , Chung Dongseop
Published: March 2018

The oil and gas (O&G) industry suffers from a negative perception of poor sustainability. O&G companies are therefore engaged in several socially sustainable activities related to community development and environmental protection. This article determines whether the social, environmental, and economic dimensions of corporate social responsibility (CSR) are equally value‐additive to O&G companies. We measure the company‐specific level of CSR activities from the information provided in the annual financial reports of O&G companies and determine the effects of CSR dimensions on firm value. We find that CSR enhances firm value of O&G companies. While social activities such as employee well‐being and community development are key value‐drivers, environmental and economic sustainable activities have an insignificant impact on the market value of O&G companies. Copyright © 2018 ASAC. Published by John Wiley & Sons, Ltd
Ultrasound assisted wet stirred media mill of high concentration LiFePO4 and catalysts
Authors: Li He , Rostamizadeh Mohammad , Mameri Kahina , Boffito Daria C. , Saadatkhah Nooshin , Rigamonti Marco Giulio , Patience Gregory S.
Published: March 2018

Wet media mills grind solids to the nanometric size and the performance of the mills depends on solids loading, particle morphology, surfactant concentration, and material characteristics. As the particle size decreases, they tend to form clusters that reduce the grinding efficiency. Ultrasound deagglomerates these clusters thereby increasing efficiency but, surprisingly, it can operate at higher solids concentrations. We processed suspensions of (LFP) with a yttria stabilized zirconia media with a size from 0.3 mm to 0.4 mm, and surfactant‐to‐LFP mass ratio 0.008. The combined method ground the particle size from 35 m down to 0.2 m in 90 min with a throughput of 0.68 /h. We also tested the improved wet media milling on two catalysts: ( and vanadyl pyrophosphate (VPP) precursor) to confirm the trends. We adopt a model for the steady state and repeatable micronizing process with ultrasonic assistance. According to TEM imaging the catalyst primary particles (20 nm) are much smaller than the agglomerated ones measured by laser diffraction (470 nm). VPP precursor slurry is normally an unstable suspension that is hard to mill. It formed agglomerates with recrystallized silica and VPP flocculation. The ultrasound‐assisted wet milling technique produced nanometer scale particles (180 nm), which is otherwise impossible. We developed and updated the steady state micronizing process with ultrasonic assistance using a simplified population balance model. The model accounts for of the variance in the experimental data.
CFD modelling of gas flow characteristics for the gas‐heating holder in environmental transmission electron microscope
Authors: Zhao Zhijian , Wang Zhiyong , Wang Dan , Wang Jie‐Xin , Pu Yuan , Chen Jian‐Feng
Published: March 2018

The environmental transmission electron microscope (ETEM) is an effective tool for understanding the behaviour of materials at an atomic level. In the present work, we have characterized the dynamics of gas flow in ETEM using computational fluid dynamic (CFD) simulations. The gas pressure drop, pressure distribution, and gas flow of different inlet pressures for a gas chamber are investigated. Based on the detailed CFD simulations, the hydrodynamics for the gas‐heating holder are carried out. Also, an attempt has been made to optimize the structure, and it is proposed that the triangle shaped inlet tube is more suitable. The results presented are useful for understanding the dynamics of gas flow in a gas chamber and provide a basis for further structure optimizations.
Energie für Chemie oder Chemie für Energie?
Authors: Wagner Tom , Flint Alfred
Published: March 2018

Als transdisziplinärer Knotenpunkt zwischen den Naturwissenschaften ist das Energie‐Konzept des Schulunterrichts auf einfache, leicht verständliche Definitionen angewiesen, die in den Fächern Chemie, Physik und Biologie gleichermaßen Gültigkeit besitzen. Auf Grundlage empirisch nachgewiesener (Fehl‐)Vorstellungen wird eine Definition für die Energie im Schulunterricht vorgeschlagen. Außerdem wird eine Möglichkeit aufgezeigt, auf den wissenschaftlich nicht haltbaren Begriff der chemischen Energie zu verzichten und stattdessen bereits im Chemieanfangsunterricht die Enthalpie einzuführen. Dazu werden einfache Experimente zu unterschiedlichen Aspekten des Themas „Energie“ in der Sekundarstufe I und die dazu passenden Enthalpie‐Diagramme vorgestellt
Prognostic relevance of subclinical coronary and carotid atherosclerosis in a diabetic and nondiabetic asymptomatic population
Authors: Guaricci Andrea Igoren , Lorenzoni Valentina , Guglielmo Marco , Mushtaq Saima , Muscogiuri Giuseppe , Cademartiri Filippo , Rabbat Mark , Andreini Daniele , Serviddio Gaetano , Gaibazzi Nicola , Pepi Mauro , Pontone Gianluca
Published: March 2018

Background

We sought to evaluate the incremental prognostic benefit of carotid artery disease and subclinical coronary artery disease (CAD) features in addition to clinical evaluation in an asymptomatic population.

Methods

Over a 6‐year period, 10‐year Framingham risk score together with carotid ultrasound and coronary computed tomography angiography were evaluated for prediction of major adverse cardiac events (MACE).

Results

We enrolled 517 consecutive asymptomatic patients (63% male, mean age 64 ±10 years; 17.6% with diabetes). Median (interquartile range) coronary artery calcium score (CACS) was 34 (0–100). Over a median follow‐up of 4.4 (3.4–5.1) years, there were 53 MACE (10%). Patients experiencing MACE had higher CACS, incidence of carotid disease, presence of CAD ≥50%, and remodeled plaque as compared with patients without MACE. At multivariable analyses, presence of CAD ≥50% (HR: 5.14, 95% CI: 2.1–12.4) and percentage of segments with remodeled plaque (HR: 1.04, 95% CI: 1.03–1.06) independently predicted MACE (P < 0.001). Models adding CAD ≥50% or percentage of segments with remodeled plaque resulted in higher discrimination and reclassification ability compared with a model based on 10‐year FRS, carotid disease, and CACS. Specifically, the C‐statistic improved to 0.75 with addition of CAD and 0.84 when adding percentage of segments with remodeled plaque, whereas net reclassification improvement indices were 0.86 and 0.92, respectively.

Conclusions

In an asymptomatic population, CAD and plaque positive remodeling increase MACE prediction compared with a model based on 10‐year FRS, carotid disease, and CACS estimation. In the diabetes subgroup, percentage of segments with remodeled plaque was the only predictor of MACE.
Electrocardiographic left ventricular hypertrophy predicts recurrence of atrial arrhythmias after catheter ablation of paroxysmal atrial fibrillation
Authors: Li Song‐Nan , Wang Lu , Dong Jian‐Zeng , Yu Rong‐Hui , Long De‐Yong , Tang Ri‐Bo , Sang Cai‐Hua , Jiang Chen‐Xi , Liu Nian , Bai Rong , Du Xin , Ma Chang‐Sheng
Published: March 2018

Background

Left ventricular hypertrophy (LVH) is an independent predictor of new‐onset atrial fibrillation. Whether LVH can predict the recurrence of arrhythmia after radiofrequency catheter ablation (RFCA) in patients with paroxysmal atrial fibrillation (PAF) remains unclear.

Hypothesis

PAF patients with baseline‐electrocardiographic LVH has a higher recurrence rate after RFCA procedure compared with those without LVH.

Methods

A total of 436 patients with PAF undergoing first RFCA were consecutively enrolled and clustered into 2 groups based on electrocardiogram (ECG) findings: non‐ECG LVH (218 patients) and ECG LVH (218 patients). LVH was characterized by the Romhilt‐Estes point score system; the score ≥5points were defined as LVH.

Results

At 42 months' (interquartile range, 18.0–60.0 months) follow‐up after RFCA, 151 (69.3%) patients in the non‐ECG LVH group and 108 (49.5%) patients in the ECG LVH group maintained sinus rhythm without using antiarrhythmic drugs (P < 0.001). Patients with ECG LVH tended to experience a much higher prevalence of stroke and recurrence of atrial arrhythmia episodes compared with those without ECG LVH (log‐rank P < 0.001). Multivariate analysis found the presence of ECG LVH and left atrial diameter to be independent risk factors for recurrence after adjusting for confounding factors.

Conclusions

The presence of ECG LVH was a strong and independent predictor of recurrence in patients with PAF following RFCA.
The role of whole‐brain radiation therapy in patients with cerebral metastases
Authors: Trifiletti Daniel M. , Brown Paul D.
Published: March 2018

In general, the role of whole‐brain radiation therapy (WBRT) in patients with cerebral metastases is evolving in favor of focused, radiosurgery‐alone approaches. Despite this, there still is a role for WBRT in many patients, and improvements in patient selection, advanced radiotherapy techniques, and novel medical and cellular therapies will continue to improve the therapeutic ratio of WBRT.
CapsidMesh: Atomic‐detail structured mesh representation of icosahedral viral capsids and the study of their mechanical properties
Authors: Alonzo‐Velázquez José Luis , Botello‐Rionda Salvador , Herrera‐Guzmán Rafael , Carrillo‐Tripp Mauricio
Published: March 2018

Viruses are the most abundant pathogens affecting all forms of life. A major component of a virus is a protein shell, known as the viral capsid, that encapsulates the genomic material. The fundamental functions of the capsid are to protect and transport the viral genome and recognize the host cell. Descriptions of this macromolecular complex have been proposed at different scales of approximation. Here, we introduce a methodology to generate a structured volumetric mesh of icosahedral viral capsids (CapsidMesh) based on the atomic positions of their constituents. Material properties of the capsid proteins can be set on every mesh element individually. Hence, we have control over all levels of protein structure (atoms, amino acids, subunits, oligomers, and capsid). The CapsidMesh models are suitable for numerical simulations and analysis of a physical process using a third‐party package. In particular, we used our methodology to generate a CapsidMesh of several capsids previously characterized by atomic force microscopy experiments and then simulated the mechanical nanoindentation through the finite element method. By fitting to the experimental linear elastic response, we estimated the elastic modulus and mechanical stresses produced on the capsids. Our results show that the atomic detail of the CapsidMesh is sufficient to reproduce anisotropic properties of the particle.
Density Functional Theory Calculations of the Quantum Capacitance of Graphene Oxide as a Supercapacitor Electrode
Authors: Song Ce , Wang Jinyan , Meng Zhaoliang , Hu Fangyuan , Jian Xigao
Published: March 2018

Graphene oxide has become an attractive electrode‐material candidate for supercapacitors thanks to its higher specific capacitance compared to graphene. The quantum capacitance makes relative contributions to the specific capacitance, which is considered as the major limitation of graphene electrodes, while the quantum capacitance of graphene oxide is rarely concerned. This study explores the quantum capacitance of graphene oxide, which bears epoxy and hydroxyl groups on its basal plane, by employing density functional theory (DFT) calculations. The results demonstrate that the total density of states near the Fermi level is significantly enhanced by introducing oxygen‐containing groups, which is beneficial for the improvement of the quantum capacitance. Moreover, the quantum capacitances of the graphene oxide with different concentrations of these two oxygen‐containing groups are compared, revealing that more epoxy and hydroxyl groups result in a higher quantum capacitance. Notably, the hydroxyl concentration has a considerable effect on the capacitive behavior.
The Antimicrobial Activity of Mononuclear Ruthenium(II) Complexes Containing the dppz Ligand
Authors: Liu Xuewen , Sun Biyun , Kell Ruby E. M. , Southam Hannah M. , Butler Jonathan A. , Li Xin , Poole Robert K. , Keene F. Richard , Collins J. Grant
Published: March 2018

The cis‐α isomer of [Ru(bb7)(dppz)]2+ (dppz=dipyrido[3,2‐a:2′,3′‐c]phenazine; bb7=bis[4(4′‐methyl‐2,2′‐bipyridyl)]‐1,7‐alkane) has been synthesised. The minimum inhibitory concentrations and the minimum bactericidal concentrations of [Ru(bb7)(dppz)]2+ and its parent complex [Ru(phen)2(dppz)]2+ (phen=1,10‐phenanthroline) were determined against a range of bacteria. The results showed that both ruthenium complexes exhibited good activity against Gram‐positive bacteria, but [Ru(bb7)(dppz)]2+ showed at least eightfold better activity against the Gram‐negative bacteria than [Ru(phen)2(dppz)]2+. Luminescence assays demonstrated that [Ru(bb7)(dppz)]2+ accumulated in a Gram‐negative bacterium to the same degree as in a Gram‐positive species, and assays with liposomes showed that [Ru(bb7)(dppz)]2+ interacted more strongly with membranes than the parent [Ru(phen)2(dppz)]2+ complex. The DNA binding affinity for [Ru(bb7)(dppz)]2+ was determined to be 6.7 × 106 m−1. Although more toxic to eukaryotic cells than [Ru(phen)2(dppz)]2+, [Ru(bb7)(dppz)]2+ exhibited greater activity against bacteria than eukaryotic cells.
Facile Synthesis of a Ternary Metal Hydroxide with Acid Treatment as an Effective and Durable Electrocatalyst in Water Oxidation
Authors: Wu Xiujuan , Xing Tongyu , Zhao Yimeng , Lee Husileng , Zhang Peili
Published: March 2018

Developing low‐cost, effective, and durable oxygen‐evolution catalysts (OECs) is still a huge challenge owing to the uphill thermodynamic reaction and the involvement of a four‐electron and four‐proton kinetics process. Herein, a facilely prepared NiCoFe(OH)x/NiOOH/NF electrode affords current densities of 10 and 100 mA cm−2 at overpotentials of 223 and 254 mV, respectively, and a Tafel slope as low as 33.5 mV dec−1 in 1 m KOH, which is superior to NiCoFe(OH)x/NF electrodes electrodeposited with a traditional method. This electrode also displays surprisingly high durability at a current density of 50 mA cm−2 for over 50 hours under alkaline conditions. Component analysis and an electrochemical study revealed that the catalytic activity enhancement of this newly prepared electrode is mainly attributed to the formation of the electrically conductive NiOOH interlayer.
One‐Step Rapid and Scalable Flame Synthesis of Efficient WO3 Photoanodes for Water Splitting
Authors: Chen Hongjun , Bo Renheng , Tran‐Phu Thanh , Liu Guanyu , Tricoli Antonio
Published: March 2018

Photoelectrochemical water splitting is a promising approach for the carbon‐free production of hydrogen using sunlight. Here, robust and efficient WO3 photoanodes for water oxidation were synthesized by the scalable one‐step flame synthesis of nanoparticle aerosols and direct gas‐phase deposition. Nanostructured WO3 films with tunable thickness and band gap and controllable porosity were fabricated by controlling the aerosol deposition time, concentration, and temperature. Optimal WO3 films demonstrate superior water oxidation performance, reaching a current density of 0.91 mA at 1.24 V vs. reversible hydrogen electrode (RHE) and an incident photon‐to‐current conversion efficiency (IPCE) of ca. 61 % at 360 nm in 0.1 m H2SO4. Notably, it is found that the excellent performance of these WO3 nanostructures arises from the high in situ restructuring temperature (ca. 1000 °C), which increases oxygen vacancies and decreases charge recombination at the WO3/electrolyte interface. These findings provide a scalable approach for the fabrication of efficient photoelectrodes based on WO3 and other metal oxides for light‐driven water splitting.
Opioid Guidelines Are a Necessary Response to the Opioid Crisis
Authors: Ballantyne Jane C. , Murinova Natalia , Krashin Daniel L.
Published: March 2018

Guidelines for opioid prescribing in noncancer pain have proliferated since the opioid crisis in the United States became widely recognized. The recently published Centers for Disease Control (CDC) guidelines for opioid prescribing have been controversial. Many of these concerns arise from underestimation of the scale of the opioid crisis, as well as misunderstanding what the guidelines actually say. Strict guidelines should be welcomed as a constructive approach to managing a thorny public health issue.
Model‐Informed Drug Development and Review for Generic Products: Summary of FDA Public Workshop
Authors: Fang Lanyan , Kim Myong‐Jin , Li Zhichuan , Wang Yaning , DiLiberti Charles E. , Au Jessie , Hooker Andrew , Ducharme Murray P. , Lionberger Robert , Zhao Liang
Published: March 2018

On October 2nd and 3rd, 2017, the US Food and Drug Administration (FDA) hosted a public workshop titled “Leveraging Quantitative Methods and Modeling to Modernize Generic Drug Development and Review.”1 This report summarizes Session 2 of the public workshop: “Model Informed Drug Development and Review for Generic Products.” The session focused on the application of quantitative methods and modeling in modernizing the generic drug development and review.
Functionalization and Properties of Tetrahydronaphtho[2,1‐a]azulene Photoswitches
Authors: Sonne Kirstine , Lindbæk Broman Søren , Drøhse Kilde Martin , Ugleholdt Petersen Anne , Brøndsted Nielsen Mogen
Published: March 2018

The front cover artwork is provided by the group of Prof. Mogens Brøndsted Nielsen at the Department of Chemistry, University of Copenhagen (Denmark). This image shows the conversion between arylated tetrahydronaphtho[2,1‐a]azulenes and their ring‐opened isomers. Read the full text of the Article at 10.1002/cptc.201700213.
Diamine‐Functionalization of a Metal–Organic Framework Adsorbent for Superb Carbon Dioxide Adsorption and Desorption Properties
Authors: Lee Woo Ram , Kim Jeong Eun , Lee Sung Jin , Kang Minjung , Kang Dong Won , Lee Hwa Young , Hiremath Vishwanath , Seo Jeong Gil , Jin Hailian , Moon Dohyun , Cho Moses , Jung Yousung , Hong Chang Seop
Published: March 2018

For real‐world postcombustion applications in the mitigation of CO2 emissions using dry sorbents, adsorption and desorption behaviors should be controlled to design and fabricate prospective materials with optimal CO2 performances. Herein, we prepared diamine‐functionalized Mg2(dobpdc) (H4dobpdc=4,4′‐dihydroxy‐(1,1′‐biphenyl)‐3,3′‐dicarboxylic acid). (1‐diamine) with ethylenediamine (en), primary–secondary (N‐ethylethylenediamine—een and N‐isopropylethylenediamine—ipen), primary–tertiary, and secondary–secondary diamines. A slight alteration of the number of alkyl substituents on the diamines and their alkyl chain length dictates the desorption temperature (Tdes) at 100 % CO2, desorption characteristics, and ΔT systematically to result in the tuning of the working capacity. The existence of bulky substituents on the diamines improves the framework stability upon exposure to O2, SO2, and water vapor, relevant to real flue‐gas conditions. Bulky substituents are also responsible for an interesting two‐step behavior observed for the ipen case, as revealed by DFT calculations. Among the diamine‐appended metal–organic frameworks, 1‐een, which has the required adsorption and desorption properties, is a promising material for sorbent‐based CO2 capture processes. Hence, CO2 performance and framework durability can be tailored by the judicial selection of the diamine structure, which enables property design at will and facilitates the development of desirable CO2‐capture materials.
Photo‐Initiated Reduction of CO2 by H2 on Silica Surface
Authors: Liu Chao , Notestein Justin M. , Weitz Eric , Gray Kimberly A.
Published: March 2018

Invited for this month's cover is the group of Prof. Kimberly Gray at Northwestern University. The Cover picture depicts a strategy to convert CO2 to CO selectively by vacuum UV photolysis via a chain radical mechanism. The Full Paper itself is available at 10.1002/cssc.201702341.
Joint server and network optimization toward load‐balanced service chaining
Authors: Thai Minh‐Tuan , Lin Ying‐Dar , Lai Yuan‐Cheng
Published: March 2018

Prior service chaining systems address server and network load balancing issues individually, which may not ensure efficient system performance. To this end, in this paper, we study the design, implementation, complexity analysis, and evaluation of Nearest First and Local‐Global Transformation algorithm, which jointly supports server and network load balancing for chaining virtualized network functions (VNFs) in data center environment. The algorithm firstly constructs service chains by a greedy strategy, which both considers server and network latency. Then a searching technique, which replaces a selected VNF with another candidate and swaps the order of VNFs in service chains, is applied to improve the solutions. We have implemented the algorithm using Software‐defined networking and OpenFlow concepts. The numerical results indicate that, compared with a sequential approach, Nearest First and Local‐Global Transformation increases the system bandwidth utilization up to 45%. The results also show that it is worth applying the second phase of our algorithm since it considerably enhances the system performance by 20%.
Improving secret key generation for wireless communications in FDD mode
Authors: Allam Ali M.
Published: March 2018

Most recent research on channel‐based key generation oriented to time division duplex system because the channel reciprocity feature is applied directly for secret key generation. Most of commercial cellular systems depend on frequency division duplex (FDD) systems. In this paper, we investigate the impact of uplink and downlink of FDD systems for the generation of shared secret keys between two parties in the presents of passive eavesdropper. In addition, we are considering improving the rate of the secret key for wireless communication in FDD mode. The main idea is to use the fading coefficient of the channels between the relay and other parties as an additional random common source for the secret key generation. Also, explore the using of channel estimation techniques to reduce the channel training sequence and study its effect on the generation of shared key for wireless communications in FDD mode. We derive the upper bound of the generated shared key rate for four scenarios and give numerical examples to reveal the performance of our suggested improvement approaches.
Regulation of C. elegans L4 cuticle collagen genes by the heterochronic protein LIN‐29
Authors: Abete‐Luzi Patricia , Eisenmann David M.
Published: March 2018

The cuticle, the outer covering of the nematode C. elegans, is synthesized five times during the worm's life by the underlying hypodermis. Cuticle collagens, the major cuticle component, are encoded by a large family of col genes and, interestingly, many of these genes express predominantly at a single developmental stage. This temporal preference motivated us to investigate the mechanisms underlying col gene expression and here we focus on a subset of col genes expressed in the L4 stage. We identified minimal promoter regions of <300 bp for col‐38, col‐49, and col‐63. In these regions, we predicted cis‐regulatory sequences and evaluated their function in vivo via mutagenesis of a col‐38p::yfp reporter. We used RNAi to study the requirement for candidate transcription regulators ELT‐1 and ELT‐3, LIN‐29, and the LIN‐29 co‐factor MAB‐10, and found LIN‐29 to be necessary for the expression of four L4‐specific genes (col‐38, col‐49, col‐63, and col‐138). Temporal misexpression of LIN‐29 was also sufficient to activate these genes at a different developmental stage. The LIN‐29 DNA‐binding domain bound the col‐38, col‐49, and col‐63 minimal promoters in vitro. For col‐38 we showed that the LIN‐29 sites necessary for reporter expression in vivo are also bound in vitro: this is the first identification of specific binding sites for LIN‐29 necessary for in vivo target gene expression.
Biodiversity matters in feedbacks between climate change and air quality: a study using an individual‐based model
Authors: Wang Bin , Shuman Jacquelyn , Shugart Herman H. , Lerdau Manuel T.
Published: March 2018

Air quality is closely associated with climate change via the biosphere because plants release large quantities of volatile organic compounds (VOC) that mediate both gaseous pollutants and aerosol dynamics. Earlier studies, which considered only leaf physiology and simply scale up from leaf‐level enhancements of emissions, suggest that climate warming enhances whole forestVOCemissions, and these increasedVOCemissions aggravate ozone pollution and secondary organic aerosol formation. Using an individual‐based forestVOCemissions model,UVAFME‐VOC, that simulates system‐level emissions by explicitly simulating forest community dynamics to the individual tree level, ecological competition among the individuals of differing size and age, and radiative transfer and leaf function through the canopy, we find that climate warming only sometimes stimulates isoprene emissions (the single largest source of non‐methane hydrocarbon) in a southeasternU.S.forest. These complex patterns result from the combination of higher temperatures’ stimulating emissions at the leaf level but decreasing the abundance of isoprene‐emitting taxa at the community level by causing a decline in the abundance of isoprene‐emitting species (Quercusspp.). This ecological effect eventually outweighs the physiological one, thus reducing overall emissions. Such reduced emissions have far‐reaching implications for the climate–air‐quality relationships that have been established on the paradigm of warming‐enhancementVOCemissions from vegetation. This local scale modeling study suggests that community ecology rather than only individual physiology should be integrated into future studies of biosphere–climate–chemistry interactions.
Fish assemblage changes over half a century in the Yellow River, China
Authors: Xie Jia Yan , Tang Wen Jia , Yang Yu Hui
Published: March 2018

Riverine environments have been threatened by anthropogenic perturbations worldwide, whereby their fish assemblages have been modified by habitat changes and nonendemic species invasions. We assessed changes in fish assemblages by comparing the species presence in historical and contemporary fish data in the Yellow River from 1965 to 2015. The temporal change in species assemblages was found with increased nonendemic species and fewer natives. Fish species richness of the river declined 35.4% over the past fifty years. Moreover, the decreased mean Bray–Curtis dissimilarity among reaches suggested that the fish assemblages of different reaches in the Yellow River were becoming more similar over time. However, temporal patterns of fish assemblages varied among reaches. In the upper Yellow River, higher species richness and more invasive species were found than those in the historical record, while the lower reaches experienced significant species loss. Dam constructions, exotic fish invasions, and flow reductions played the vital role in structuring the temporal fish assemblages in the Yellow River. It is suggested that river basins which experienced different types and levels of stressors by anthropogenic perturbations can produce varied effects on their temporal trends of species assemblages.
An in vitro evaluation of browser and grazer fermentation efficiency and microbiota using European moose spring and summer foods
Authors: Krizsan Sophie J. , Mateos‐Rivera Alejandro , Bertilsson Stefan , Felton Annika , Anttila Anne , Ramin Mohammad , Vaga Merko , Gidlund Helena , Huhtanen Pekka
Published: March 2018

Evolutionary morphological and physiological differences between browsers and grazers contribute to species‐specific digestion efficiency of food resources. Rumen microbial community structure of browsers is supposedly adapted to characteristic nutrient composition of the diet source. If this assumption is correct, domesticated ruminants, or grazers, are poor model animals for assessing the nutritional value of food consumed by browsing game species. In this study, typical spring and summer foods of the European moose (Alces alces) were combined with rumen fluid collected from both dairy cows (Bos taurus) and from moose, with the aim of comparing fermentation efficiency and microbial community composition. The nutritional value of the food resources was characterized by chemical analysis and advanced in vitro measurements. The study also addressed whether or not feed evaluation based on in vitro techniques with cattle rumen fluid as inoculum could be a practical alternative when evaluating the nutritional value of plants consumed by wild browsers. Our results suggest that the fermentation characteristics of moose spring and summer food are partly host‐specific and related to the contribution of the bacterial phyla Firmicutes and Bacteriodetes to the rumen microbial community. Host‐specific adaptations of the ruminal microbial community structure could be explained from the evolutionary adaptations related to feeding habitats and morphophysiological differences between browsers and grazers. However, the observed overall differences in microbial community structure could not be related to ruminal digestion parameters measured in vitro. The in vitro evaluation of digestion efficiency reveals that equal amounts of methane were produced across all feed samples regardless of whether the ruminal fluid was from moose or dairy cow. The results of this study suggested that the nutritional value of browsers' spring and summer food can be predicted using rumen fluid from domesticated grazers as inoculum in in vitro assessments of extent of digestion when excluding samples of the white water lily root, but not of fermentation characteristics as indicated by the proportions of individual fermentation fatty acids to the total of volatile fatty acids.
Tropical herbivorous phasmids, but not litter snails, alter decomposition rates by modifying litter bacteria
Authors: Prather Chelse M. , Belovsky Gary E. , Cantrell Sharon A. , González Grizelle
Published: March 2018

Consumers can alter decomposition rates through both feces and selective feeding in many ecosystems, but these combined effects have seldom been examined in tropical ecosystems. Members of the detrital food web (litter‐feeders or microbivores) should presumably have greater effects on decomposition than herbivores, members of the green food web. Using litterbag experiments within a field enclosure experiment, we determined the relative effects of common litter snails (Megalomastoma croceum) and herbivorous walking sticks (Lamponius portoricensis) on litter composition, decomposition rates, and microbes in a Puerto Rican rainforest, and whether consumer effects were altered by canopy cover presence. Although canopy presence did not alter consumers' effects, focal organisms had unexpected influences on decomposition. Decomposition was not altered by litter snails, but herbivorous walking sticks reduced leaf decomposition by about 50% through reductions in high quality litter abundance and, consequently, lower bacterial richness and abundance. This relatively unexplored but potentially important link between tropical herbivores, detritus, and litter microbes in this forest demonstrates the need to consider autotrophic influences when examining rainforest ecosystem processes.
Lipophilicity predicts the ability of nonsulphonylurea drugs to block pancreatic beta‐cell KATP channels and stimulate insulin secretion; statins as a test case
Authors: Real Joana , Miranda Caroline , Olofsson Charlotta S. , Smith Paul A.
Published: March 2018

Aims

KATP ion channels play a key role in glucose‐stimulated insulin secretion. However, many drugs block KATP as “off targets” leading to hyperinsulinaemia and hypoglycaemia. As such drugs are often lipophilic, the aim was to examine the relationship between drug lipophilicity (P) and IC50 for KATP block and explore if the IC50's of statins could be predicted from their lipophilicity and whether this would allow one to forecast their acute action on insulin secretion.

Materials and methods

A meta‐analysis of 26 lipophilic, nonsulphonylurea, blockers of KATP was performed. From this, the IC50's for pravastatin and simvastatin were predicted and then tested experimentally by exploring their effects on KATP channel activity via patch‐clamp measurement, calcium imaging and insulin secretion in murine beta cells and islets.

Results

Nonsulphonylurea drugs inhibited KATP channels with a Log IC50 linearly related to their logP. Simvastatin blocked KATP with an IC50 of 25 nmol/L, a value independent of cytosolic factors, and within the range predicted by its lipophilicity (21‐690 nmol/L). 10 μmol/L pravastatin, predicted IC50 0.2‐12 mmol/L, was without effect on the KATP channel. At 10‐fold therapeutic levels, 100 nmol/L simvastatin depolarized the beta‐cell membrane potential and stimulated Ca2+ influx but did not affect insulin secretion; the latter could be explained by serum binding.

Conclusions

The logP of a drug can aid prediction for its ability to block beta‐cell KATP ion channels. However, although the IC50 for the block of KATP by simvastatin was predicted, the difference between this and therapeutic levels, as well as serum sequestration, explains why hypoglycaemia is unlikely to be observed with acute use of this statin.
Peripherally induced regulatory T cells contribute to the control of autoimmune diabetes in the NOD mouse model
Authors: Schuster Cornelia , Jonas Franziska , Zhao Fangzhu , Kissler Stephan
Published: March 2018

Type 1 diabetes (T1D) results from the autoimmune destruction of pancreatic beta cells and is partly caused by deficiencies in the Foxp3+ regulatory T‐cell (Treg) compartment. Conversely, therapies that increase Treg function can prevent autoimmune diabetes in animal models. The majority of Tregs develop in the thymus (tTregs), but a proportion of Foxp3+ Tregs is generated in the periphery (pTregs) from Foxp3−CD4+ T‐cell precursors. Whether pTregs play a distinct role in T1D has not yet been explored. We report here that pTregs are a key modifier of disease in the nonobese diabetic (NOD) mouse model for T1D. We generated NOD mice deficient for the Foxp3 enhancer CNS1 involved in pTreg induction. We show that CNS1 knockout decreased the frequency of pTregs and increased the risk of diabetes. Our results show that pTregs fulfill an important non‐redundant function in the prevention of beta cell autoimmunity that causes T1D.
Synthesis and Properties of Monophospha‐ and Diphosphacyclodiynes
Authors: Popp Ralf , Gleiter Rolf , Haberhauer Gebhard , Rominger Frank
Published: March 2018

This paper reports the synthesis and characterization of a number of monocyclic systems with one or two phosphorus atoms in the scaffold. The cyclic systems with one P‐atom are: 1‐phosphacyclodeca‐3,8‐diyne, 1‐phosphacycloundeca‐3,9‐diyne, 1‐phosphacyclododeca‐3,10‐diyne, 1‐phosphacyclotrideca‐3,11‐diyne, 1‐phosphacyclotetradeca‐3,12‐diyne and 1‐phosphacyclotetradeca‐4,11‐diyne. The P‐centers in the rings were further stabilized by phenyl‐ or 2,4,6‐tri‐tert‐butylphenyl rings as third ligand and sulfur or oxygen atoms as fourth ligand. The rings with two P‐atoms are 1,8‐diphospha‐cyclotetradeca‐4,11‐diyne and 1,10‐diphosphacyclooctadeca‐5,14‐diyne, with phenyl rings and oxygen at the P‐centers. For many of the products the structures and conformations in the solid state were obtained by X‐ray studies.
Design of Experiments Approach to Provide Enhanced Glucose‐oxidising Enzyme Electrode for Membrane‐less Enzymatic Fuel Cells Operating in Human Physiological Fluids
Authors: Bennett Richard , Osadebe Isioma , Kumar Rakesh , Conghaile Peter Ó , Leech Dónal
Published: March 2018

Graphite electrodes are modified with a redox polymer, [Os(4,4′‐dimethoxy‐2,2′‐bipyridine)2(polyvinylimidazole)10Cl]+ (E°′=−0.02 V vs Ag/AgCl (3 M KCl), crosslinked with a flavin adenine dinucleotide glucose dehydrogenase and multi‐walled carbon nanotubes for electrocatalytic oxidation of glucose. The enzyme electrodes provide 52 % higher current density, 1.22±0.10 mA cm−2 in 50 mM phosphate‐buffered saline at 37 °C containing 5 mM glucose, when component amounts are optimised using a design of experiments approach compared to one‐factor‐at‐a‐time. Current densities of 0.84±0.15 mA cm−2 were achieved in the presence of oxygen for these enzyme electrodes. Further analysis of the model allowed for altering of the electrode components while maintaining similar current densities, 0.78±0.11 mA cm−2 with 34 % less enzyme. Application of the cost‐effective anodes in membrane‐less enzymatic fuel cells is demonstrated by connection to cathodes prepared by co‐immobilisation of [Os(2,2′‐bipyridine)2(polyvinylimidazole)10Cl+] redox polymer, Myrothecium verrucaria bilirubin oxidase and multi‐walled carbon nanotubes on graphite electrodes. Power densities of up to 285 μW cm−2, 146 μW cm−2 and 60 μW cm−2 are achieved in pseudo‐physiological buffer, artificial plasma and human plasma respectively, showing promise for in vivo or ex vivo power generation under these conditions.
Regional Differences in Dopamine Release in the R6/2 Mouse Caudate Putamen
Authors: Kaplan Sam V. , Limbocker Ryan A. , Levant Beth , Johnson Michael A.
Published: March 2018

Huntington's disease (HD) is a fatal neurodegenerative disorder that is characterized by degeneration of the striatum. Here, fast‐scan cyclic voltammetry at carbon‐fiber microelectrodes was used to uncover regional differences in dopamine (DA) release in the caudate putamen of R6/2 and wild‐type control mice. We found a decreasing ventral‐to‐dorsal gradient in DA release, evoked by a single electrical stimulus pulse, in aged R6/2 mice. Moreover, under more intense stimulation conditions (120 pulses), DA release was significantly attenuated in the dorsal, but not in the ventral caudate. Autoradiography measurements using [3H] WIN 35,428 revealed that the overall density of DA transporter (DAT) protein molecules was significantly less in R6/2 mice compared to WT control mice; however, quadrants of the caudate putamen were not differentially altered in the R6/2 mice. These data collectively suggest that DA release in the dorsal caudate region is more vulnerable with age progression compared to the ventral region.
Novel Green Potentiometric Method for the Determination of Lidocaine Hydrochloride and its Metabolite 2, 6‐Dimethylaniline; Application to Pharmaceutical Dosage Form and Milk
Authors: Saad Ahmed Sayed , Alamein Amal Mahmoud Abou Al , Galal Maha Mohammed , Zaazaa Hala Elsayed
Published: March 2018

Sustainable chemistry has attracted the attention of scientists during the last decades owing to the great advantages encountered by its application. These include: waste reduction, energy conservation and substitution of hazardous substances with more eco‐friendly ones. Following this approach, a new sensitive and selective membrane sensor was developed and investigated for the determination of lidocaine hydrochloride (LD) and its carcinogenic metabolite 2,6‐dimethylaniline (DMA). Several polyvinyl chloride (PVC) based sensors were tried using different plasticizers as well as different cation exchangers. The best response was achieved upon using dioctylphthalate (DOP) as solvent mediator and phosphotungstate (PT) as cation exchanger. LD was selectively determined at pH 6 without interference from its carcinogenic metabolite, while DMA that had been reported to be the toxic inactive metabolite of LD secreted in the milk was determined in the milk at pH 2. Fast, stable Nernstian responses were achieved by the proposed sensors over a concentration range of 2.66×10−5 M to 1×10−2 M for both LD and DMA. The method was validated according to the IUPAC recommendations and was successfully applied for the determination of LD in pure form and pharmaceutical dosage form, whereas DMA was successfully determined in pure form and spiked milk samples.
Improving the Performance of a Perovskite Solar Cell by Adjusting the Dispersant for Titanium Dioxide
Authors: Jia Jinbiao , Wu Jihuai , Dong Jia , Bao Quanlin , Ge Jihua , Lan Zhang , Lin Jianming , Fan Leqing , Huang Miaoliang
Published: March 2018

The electron‐transport layer (ETL) plays an important role in the photovoltaic performance of perovskite solar cells (PSCs). In this work, titanium dioxide (TiO2) nanoparticles are synthetized by a hydrothermal method. The as‐synthesized TiO2 is dispersed into different alcoholic solvents with different lengths of the carbon chain. The TiO2 ETL is fabricated by spin‐coating TiO2 paste onto a TiO2 blocking layer/FTO. Scanning electron microscopy, atomic force microscopy, steady‐state photoluminescence, time‐resolved photoluminescence, and the photovoltaic performance of the samples and devices are investigated. The results show that the n‐pentanol dispersant can effectively reduce the pinholes and trap states of the TiO2 ETL layer, which enhances the charge carrier transport efficiency and reduces charge recombination. The device achieves an optimal power conversion efficiency of 18.16 %, which is an increase by 23.28 % compared to the common method of using ethanol as the dispersant.