bluuebunny/crossref_metadata_2025 huggingface dataset:
Scale‐up analysis of autothermal operation of methane oxidative coupling with La2O3/CaO catalyst
Authors: Sun Zhe , West David H. , Gautam Pankaj , Balakotaiah Vemuri
Published: February 2020

The exothermicity of oxidative coupling of methane (OCM) renders a cooled packed‐bed reactor impractical or impossible. Recently, we proposed an adiabatic autothermal reactor as a solution to this problem and reported the first results for stable autothermal operation (AO) with feed at ambient temperature. AO on the ignited branch is possible only in the region of steady‐state multiplicity. High per‐pass conversion and productivity requirements demand a stable ignited branch at the lowest possible feed temperature and high flow rate. To achieve OCM scale‐up, many conditions must be satisfied simultaneously. Using a kinetic model for La2O3/CaO catalyst, we examine the impact of space time, feed methane to oxygen ratio, feed temperature, particle size, inter‐phase heat and mass transfer gradients, pore‐diffusion, bed scale heat/mass dispersion on the region of AO for large scale adiabatic packed‐bed reactors. We show that while it is possible to achieve CH4 conversion of about 20% and C2 selectivity of about 80% in scaled‐up reactors, these values are sensitive to the design and operating parameters.
A Bayesian State‐Space Approach for Invasive Species Management: The Case of Spotted Wing Drosophila
Authors: Fan Xiaoli , Gómez Miguel I. , Atallah Shady S. , Conrad Jon M.
Published: February 2020

Spotted wing drosophila (SWD) is an invasive pest with devastating effects on soft‐skinned fruit crops. Due to its high economic impacts, current SWD management strategies usually focus on preventive calendar‐based insecticide sprays. The industry is calling for adoption of monitoring‐based integrated pest management (IPM) strategies to reduce unnecessary insecticide applications. However, because traps are costly and do not provide perfect observations of the population size, most growers do not monitor. We develop a Bayesian state‐space bioeconomic framework to inform the optimal SWD management strategy when observational uncertainty exists. We use Bayesian inference via the Markov Chain Monte Carlo method to generate the posterior distribution of population model parameters, which we then use to simulate the economic performance of alternative SWD management strategies. We find that one of the monitoring‐based IPM strategies has a slightly lower total cost than the calendar‐based spray strategy. We also find evidence of misalignments between public and private incentives in the adoption of IPM strategies. Profit‐maximizing growers who ignore the negative externalities of insecticide spray have little incentive to adopt the IPM strategies. However, for environmentally conscious growers who take into account the external costs of insecticide sprays, IPM strategies are superior to calendar‐based spray strategy. Our results indicate that IPM strategies become more appealing to both types of growers as the trapping efficiency improves. Extension efforts, support for research to improve trapping efficiency, and monetary incentives can be used to encourage grower adoption of monitoring‐based IPM strategies to control SWD infestation.
Topological Phase Transition and Phase Diagrams in a Two‐Leg Kitaev Ladder System
Authors: Yan Yu , Qi Lu , Wang Dong‐Yang , Xing Yan , Wang Hong‐Fu , Zhang Shou
Published: February 2020

A scheme to investigate the topological properties in a two‐leg Kitaev ladder system composed of two Kitaev chains is proposed. In the case of two identical Kitaev chains, it is found that the interchain hopping amplitude plays a significant role in the separation of the energy spectrum and in inducing a topologically nontrivial phase, while the interchain pairing strength only affects the size of the energy gap. Moreover, another situation that the system consists of two non‐identical Kitaev chains is also investigated and the corresponding phase diagram is calculated. It is found that two pairs of degenerate nonzero edge modes will, respectively, appear in the upper and lower energy gaps when the interchain hopping amplitude or the interchain pairing strength is large enough. Furthermore, it is pointed out that the winding number is quantitatively equivalent to half of the number of zero energy edge modes in our system.
π‐Interactions between Cyclic Carbocations and Aromatics Cause Zeolite Deactivation in Methanol‐to‐Hydrocarbon Conversion
Authors: Wang Chao , Hu Min , Chu Yueying , Zhou Xue , Wang Qiang , Qi Guodong , Li Shenhui , Xu Jun , Deng Feng
Published: February 2020

The understanding of catalyst deactivation represents one of the major challenges for the methanol‐to‐hydrocarbon (MTH) reaction over acidic zeolites. Here we report the critical role of intermolecular π‐interactions in catalyst deactivation in the MTH reaction on zeolites H‐SSZ‐13 and H‐ZSM‐5. π‐interaction‐induced spatial proximities between cyclopentenyl cations and aromatics in the confined channels and/or cages of zeolites are revealed by two‐dimensional solid‐state NMR spectroscopy. The formation of naphtalene as a precursor to coke species is favored due to the reaction of aromatics with the nearby cyclopentenyl cations and correlates with both acid density and zeolite topology.
Orthogonal Cationic and Radical RAFT Polymerizations to Prepare Bottlebrush Polymers
Authors: Tanaka Joji , Häkkinen Satu , Boeck Parker T. , Cong Yidan , Perrier Sébastien , Sheiko Sergei S. , You Wei
Published: February 2020

An orthogonal combination of cationic and radical RAFT polymerizations is used to synthesize bottlebrush polymers using two distinct RAFT agents. Selective consumption of the first RAFT agent is used to control the cationic RAFT polymerization of a vinyl ether monomer bearing a secondary dormant RAFT agent, which subsequently allows side‐chain polymers to be grafted from the pendant RAFT agent by a radical‐mediated RAFT polymerization of a different monomer, thus completing the synthesis of bottlebrush polymers. The high efficiency and selectivity of the cationic and radical RAFT polymerizations allow both polymerizations to be conducted in one‐pot tandem without intermediate purification.
Construction of Various Bridged Polycyclic Skeletons by Palladium‐Catalyzed Dearomatization
Authors: Mu Xingye , Yu Hanxiao , Peng Henian , Xiong Wenrui , Wu Ting , Tang Wenjun
Published: February 2020

A powerful palladium‐catalyzed dearomative cyclization was developed that provides facile access to eight types of bridged tetracyclic skeletons bearing various ring sizes and heterocycles. With this method, several skeletons or analogues of natural products, including tubingensin B and dracaenones, were synthesized. Asymmetric dearomative cyclization enables the construction of various enantiomerically enriched bridged polycyclic systems with up to 99 %eeby employing a chiral palladium catalyst.
Deep insight into interaction mechanisms between ESBR and silica modified by different silane coupling agents
Authors: Wang Chen , Li Ai , Kong Miqiu , Yang Qi , Lv Yadong , Huang Yajiang , Li Guangxian
Published: February 2020

In this study, the interaction mechanisms of different silane coupling agents on the mechanical properties, dynamic viscoelastic properties, and rheological properties of emulsion styrene‐butadiene rubber (ESBR)/silica composites were investigated. It is found that the comprehensive performances are improved by the addition of silane coupling agents and the optimal performance is exhibited in ESBR filled with 50 phr modified silica. Moreover, with the addition of the bis‐(3‐triethoxysilylpropyl)‐tetrasulfide modified silica, the wet skid resistance of composites is significantly enhanced by 14.0%, whereas by the addition of 3‐octanoylthio‐1‐propyltriethoxysilane modified silica, the rolling resistance is remarkably reduced by 19.6% and the processing safety is improved. It can be attributed to the increased bound rubber contents induced by the enhanced interactions between the modified silica and rubber matrix characterized by rheological properties. Furthermore, it is pointed out that the second layer bound rubber plays a dominant role in the improved properties of the composites.
Optical biosensor for catechol determination based on laccase‐immobilized anionic polyamide 6 microparticles
Authors: Cano‐Raya Clara , Dencheva Nadya V. , Braz Joana F. , Malfois Marc , Denchev Zlatan Z.
Published: February 2020

This work presents the preparation, optimization, and testing of an enzyme‐based optical biosensor for catechol determination. The sensing area is attached to a glass support and contains: anionic polyamide 6 (PA6) porous microparticles supporting laccase from Trametes Versicolor, embedded in a Pebax® MH1657 polymer binder that contains the optical indicator dye 3‐methyl‐2‐benzothiazolinone hydrazone (MBTH), responsible for the optical transduction. The catechol analyte, after its enzymatic oxidation, forms o‐benzoquinone that can be detected by oxidative coupling with MBTH giving rise to a colored product. The latter can be quantified measuring the UV/VIS absorbance at 500 nm. The PA6 microparticles performed as useful laccase carriers reaching high immobilization yields of up to 99.8% and preserving the enzyme catalytic activity. This permitted the preparation of a new biosensor presenting a detection limit of 11 μM and responding linearly to up to 118 μM of catechol. Biosensor applicability was tested in spiked natural water samples from river and spring. The recovery rates observed were in the range of 97–108% that proves the good accuracy of the proposed biosensor.
Mechanical, thermal, and structural properties of uniaxially drawn polylactic acid/halloysite nanocomposites
Authors: Bagheri Ehsan , Mosaddegh Peiman , Behzad Tayebeh
Published: February 2020

The effect of solid‐state drawing at different conditions including drawing ratio (DR), drawing temperature (DT), and drawing speed (DS) on mechanical, thermal, and structural properties of polylactic acid (PLA)/halloysite nanotubes (HNTs) composites were studied. PLA/HNTs composite films were prepared by melt mixing process followed by compression molding. Subsequently, drawing was performed using a tensile testing machine. Field emission scanning electron microscopy confirmed alignment and orientation of polymer chains and HNTs after stretching. Thermal and mechanical analysis of the drawn films revealed that glass transition temperature, crystallinity, ultimate tensile strength, and Young's modulus were enhanced by increasing DR, DT, and DS. However, toughness was decreased by increasing DR and DS and increased by increasing DT. In addition, the drawn nanocomposites showed superior mechanical and thermal properties compared to the drawn neat PLA films indicating the high efficiency of solid‐state drawing and positive effect of HNTs. Therefore, this study could be helpful to introduce an approach to enhance the properties of biopolymers and renewable polymers by uniaxial drawing.
Inexpensive throughfall exclusion experiment for single large trees
Authors: Cranston Benjamin M. , Powers Breanna F. , Macinnis‐Ng Cate
Published: February 2020

Premise

Drought‐induced tree mortality is an emergent threat to forests worldwide, particularly to large trees. Drought‐manipulation experiments involving throughfall exclusion (TFE) tend to focus on large plots that can be expensive to establish and maintain and may be unsuitable for large trees or indigenous forests. We set out to establish a relatively inexpensive TFE method in a natural forest with large trees.

Methods

We designed a novel TFE method and installed it in the Waitākere Range of West Auckland, New Zealand, to study the southern conifer kauri (Agathis australis) under long‐term simulated drought. We measured fluxes of water (sap flow) and carbon (stem increment and litterfall) as indicators of drought effects.

Results

Throughfall was cut off to a 22.25‐m2 area around individual boles, causing reduced soil moisture and reduced sap flow in droughted trees.

Discussion

Our new TFE method centered on individual, large trees in native forest and is highly customizable to fit other forest and species types. It can be used to assess physiological responses to drought of individual trees independent of stem size.
Application work using software tools and didactic equipment of electrical machines in electrical engineering studies
Authors: Torrent Marcel , Martinez Eusebi , Perat José I.
Published: February 2020

This article describes the use of software tools and didactic equipment of electrical machines applied to the teaching in electrical engineering, specifically in the realization of an application work consisting of the characterization of the three‐phase induction motor. Several studies have explored the effectiveness of teaching activities, which encompass different learning tools in the same work, from the use of didactic materials to the use of professional computer tools. The objective is the simultaneous use of didactic equipment and the calculation methodologies through specific software of industrial applications in engineering studies. In addition, to observe whether performing application work that implementing different techniques at the same time fosters the critical spirit among students. The activities students must do in the application work proposed in the subject of rotating electrical machines is to determine all the constructive variables of an induction motor, draw it, simulate its electromagnetic behavior by finite element method with a freeware available 2D program, test the motor in the laboratory following the guidelines of the current standards and, finally, compare the results obtained from the tests and the simulation, by making a critique of the results and the calculation methodology used. The application work presented in the article has been implemented during several courses in the subject of electrical machines for electrical engineering students, with satisfactory results.
An investigation of the droplet size distributions in a cyclone reactor for liquid‐liquid heterogeneous reactions using FBRM and PVM
Authors: Zhang Mingyang , Li Xiaoyu , Zhang Linhua , Wang Zhenbo , Xiao Xue , Zhu Liyun
Published: February 2020

A multi‐element process coupled cyclone reactor for the liquid‐liquid heterogeneous reaction was proposed. This paper presents the investigation of dispersed phase droplet size distributions near the wall surface using FBRM and PVM. To translate a chord length distribution (CLD) measured by the FBRM instrument into its droplet size distribution (DSD), a CLD‐DSD transformation model was proposed. Moreover, the effects of operational parameters on the droplet size distributions were studied. The results show that the total inlet flow plays a decisive role on the dispersed phase droplet size distributions, while the influence of feed ratio is mainly reflected in inhibiting the probability of droplet coalescence. In comparison, the influence of overflow ratio on the droplet size distributions can be neglected.
Axially Chiral Cannabinols: A New Platform for Cannabinoid‐Inspired Drug Discovery
Authors: Navaratne Primali V. , Wilkerson Jenny L. , Ranasinghe Kavindri D. , Semenova Evgeniya , Felix Jasmine S. , Ghiviriga Ion , Roitberg Adrian , McMahon Lance R. , Grenning Alexander J.
Published: February 2020

Phytocannabinoids (and synthetic analogs thereof) are gaining significant attention as promising leads in modern medicine. Considering this, new directions for the design of phytocannabinoid‐inspired molecules is of immediate interest. In this regard, we have hypothesized that axially‐chiral‐cannabinols (ax‐CBNs), unnatural and unknown isomers of cannabinol (CBN) may be valuable scaffolds for cannabinoid‐inspired drug discovery. There are two main factors directing our interest to these scaffolds: (a) ax‐CBNs would have ground‐state three‐dimensionality; ligand‐receptor interactions can be more significant with complimentary 3D‐topology, and (b) ax‐CBNs at their core structure are biaryl molecules, generally attractive platforms for pharmaceutical development due to their ease of functionalization and stability. Herein we report a synthesis of ax‐CBNs, examine physical properties experimentally and computationally, and perform a comparative analysis of ax‐CBN and THC in mice behavioral studies.
Characterization of Drosophila octopamine receptor neuronal expression using MiMIC‐converted Gal4 lines
Authors: McKinney Hannah M. , Sherer Lewis M. , Williams Jessica L. , Certel Sarah J. , Stowers R. Steven
Published: February 2020

Octopamine, the invertebrate analog of norepinephrine, is known to modulate a large variety of behaviors in Drosophila including feeding initiation, locomotion, aggression, and courtship, among many others. Significantly less is known about the identity of the neurons that receive octopamine input and how they mediate octopamine‐regulated behaviors. Here, we characterize adult neuronal expression of MiMIC‐converted Trojan‐Gal4 lines for each of the five Drosophila octopamine receptors. Broad neuronal expression was observed for all five octopamine receptors, yet distinct differences among them were also apparent. Use of immunostaining for the octopamine neurotransmitter synthesis enzyme Tdc2, along with a novel genome‐edited conditional Tdc2‐LexA driver, revealed all five octopamine receptors express in Tdc2/octopamine neurons to varying degrees. This suggests autoreception may be an important circuit mechanism by which octopamine modulates behavior.
Study on the preference of city color image selection based on the logistic model: A case study of Shanghai
Authors: Wang Jiangbo , Zhang Lingyun , Gou Aiping
Published: February 2020

With the continuous progress of urbanization, China's urban color planning has begun to receive attention, but there are still many problems in the quality of color environment. In order to clarify further the urban color positioning of our country, the detailed urban color planning objectives are set up, and the opinions of residents with different attributes are included in the consideration scope of urban color planning objectives, so as to guide the future urban color planning scientifically. From the perspective of urban residents' preference, this article takes Shanghai as an example to analyze the difference of residents' preference for urban color selection with different attributes. In this article, the logistic regression model was used to analyze the results of residents' choice, so as to conclude that the significant factors influencing residents' preference for city color image include age, monthly income, current city of residence, frequency of coming to Shanghai and whether they have been to other countries. Therefore, paying attention to the above significant attributes of residents and carrying out in‐depth research can provide reference value for the status of the city's future color image.
Chief executive officer narcissism and firm value: The mediating role of corporate social responsibility in the South Korean context
Authors: Yook Keun‐Hyo , Lee Su‐Yol
Published: February 2020

This study analyzes whether narcissism in chief executive officers (CEOs) affects firm value through the promotion of corporate social responsibility (CSR) initiatives. Employing the upper‐echelons perspective, we present a research framework for the relationship between CEO narcissism and firm performance with CSR as the mediation variable. The results of the regression analysis of 265 firm‐year South Korean samples from 2010 to 2016 indicate that CEO narcissism promotes CSR initiatives and CSR enhances firm value in the capital market. However, the results do not provide evidence that CSR mediates the link between CEO narcissism and desirable organizational outcomes. The findings of this study build a better theoretical and practical understanding of the antecedents and consequences of CSR from the CEO's psychological personality perspective.
Biomass‐Derived Carbons for Sodium‐Ion Batteries and Sodium‐Ion Capacitors
Authors: Zhu Jianhui , Roscow James , Chandrasekaran Sundaram , Deng Libo , Zhang Peixin , He Tingshu , Wang Kuo , Huang Licong
Published: February 2020

In the past decade, the rapid development of portable electronic devices, electric vehicles, and electrical devices has stimulated extensive interest in fundamental research and the commercialization of electrochemical energy‐storage systems. Biomass‐derived carbon has garnered significant research attention as an efficient, inexpensive, and eco‐friendly active material for energy‐storage systems. Therefore, high‐performance carbonaceous materials, derived from renewable sources, have been utilized as electrode materials in sodium‐ion batteries and sodium‐ion capacitors. Herein, the charge‐storage mechanism and utilization of biomass‐derived carbon for sodium storage in batteries and capacitors are summarized. In particular, the structure–performance relationship of biomass‐derived carbon for sodium storage in the form of batteries and capacitors is discussed. Despite the fact that further research is required to optimize the process and application of biomass‐derived carbon in energy‐storage devices, the current review demonstrates the potential of carbonaceous materials for next‐generation sodium‐related energy‐storage applications.
Insight into the Superior Lithium Storage Properties of Ultrafine CoO Nanoparticles Confined in a 3 D Bimodal Ordered Mesoporous Carbon CMK‐9 Anode
Authors: Saikia Diganta , Deka Juti Rani , Lin Cheng‐Wei , Lai Yuan‐Hung , Zeng Yu‐Hao , Chen Po‐Hung , Kao Hsien‐Ming , Yang Yung‐Chin
Published: February 2020

Ultrafine CoO particles immobilized into the mesopores of three‐dimensional cubic bimodal ordered mesoporous carbon CMK‐9 is successfully prepared by using a combination of nanocasting and wet‐impregnation methods. It is found that the cubic bimodal interconnected mesoporous framework of CMK‐9 plays a crucial role in achieving the excellent electrochemical performances by assisting the rapid mass and charge transfer. Among the prepared nanocomposites, CoO(10)@CMK‐9 delivers a discharge capacity of 830 mAh g−1 after 200 cycles at a current density of 100 mA g−1 in lithium‐ion batteries. At a higher current density of 1000 mA g−1, the anode presents an outstanding discharge capacity of 636 mAh g−1 after 200 cycles. In sodium‐ion batteries, the anode provides a discharge capacity of 296 mAh g−1 after 250 cycles at a current density of 100 mA g−1. The remarkable performances of CoO(10)@CMK‐9 demonstrate the promising potentials of the nanocomposite as the anode for rechargeable batteries.
C2–H Arylation of Indoles Catalyzed by Palladium‐Containing Metal‐Organic‐Framework in γ‐Valerolactone
Authors: Anastasiou Ioannis , Van Velthoven Niels , Tomarelli Elena , Lombi Aurora , Lanari Daniela , Liu Pei , Bals Sara , De Vos Dirk E. , Vaccaro Luigi
Published: February 2020

An efficient and selective procedure was developed for the direct C2–H arylation of indoles using a Pd‐loaded metal–organic framework (MOF) as a heterogeneous catalyst and the nontoxic biomass‐derived solvent γ‐valerolactone (GVL) as a reaction medium. The developed method allows for excellent yields and C‐2 selectivity to be achieved and tolerates various substituents on the indole scaffold. The established conditions ensure the stability of the catalyst as well as recoverability, reusability, and low metal leaching into the solution.
Performance analysis and hardware implementation of a nearly optimal buffer management scheme for high‐performance shared‐memory switches
Authors: Zheng Ling , Pan Weitao , Li Yinghua , Gao Ya
Published: February 2020

Burst traffic is a common traffic pattern in modern IP networks, and it may lead to the unfairness problem and seriously degrade the performance of switches and routers. From the perspective of switching mechanism, the majority of commercial switches adopt the on‐chip shared‐memory switching architecture, and high‐speed packet buffer with efficient queue management is required to deal with the unfairness and congestion problem. In this paper, the performance of a shared‐private buffer management scheme is analyzed in detail. In the proposed scheme, the total memory space is split into shared area and private area. Each output port has a private memory area that cannot be used by other ports. The shared area is completely shared among all output ports. A theoretical queuing model of the proposed scheme is formulated, and closed‐form formulas for multiple performance parameters are derived. Through the numerical studies, we demonstrate that a nearly optimal buffer partition policy can be obtained by setting an equally small amount of private area for each queue. This work is validated by simulations as well as hardware experiments. Software simulations show that the proposed scheme performs better than existing methods, and packet dropping caused by burst traffic can be significantly reduced. Besides, a prototype of the buffer management module is implemented and evaluated in field programmable gate array platform. The evaluation shows that the proposed scheme can ensure the efficiency and fairness while keeping a high throughput in real workload.
Mucinous breast carcinoma metastatic to thyroid gland: Report of a case diagnosed by fine‐needle aspiration cytology
Authors: Wang Meixian , Liu Xiulan , Wei Bing , Liu Nian , Li Qiyuan , Su Xueying
Published: February 2020

Mucinous breast cancer is a slow‐growing neoplasm, which has fewer lymph node metastases and favorable prognosis compared with invasive breast cancer no special type. The hematogenous spread of breast mucinous carcinoma is very rare. Though breast cancer involving thyroid has been reported before, there is still no report about thyroid metastatic breast mucinous carcinoma in the literature. Recently by performing thyroid fine‐needle aspiration, a 58‐year‐old woman who had breast cancer 13 years ago was diagnosed as thyroid metastatic mucinous breast carcinoma, cellular variant with neuroendocrine differentiation. For this patient, the thyroid was the only involved site without widespread metastatic diseases, so thyroidectomy and the right cervical lymph nodes dissection were performed to make better survival. As a result, the patient had not shown any signs of recurrence 9 months after the thyroid surgery.
Hematocrit, blood volume, and surface area of dried blood spots – a quantitative model
Authors: Alsous Mervat M. , Hawwa Ahmed F. , McElnay James C.
Published: February 2020

The use of the dried blood spot (DBS) sampling technique has extended the scope of clinical research, particularly in children. The effects of different hematocrit levels (25–55%) and different blood volumes (7.5–30 μL) on the surface area of the blood spots were investigated using ImageJ® software. Variation in hematocrit levels between patients and inaccuracies in blood volumes applied to Guthrie cards can have a marked effect on analyte concentrations measured in DBS samples. The current study presents a validated model that links blood volume and hematocrit to the surface area of the blood spot. The final model showed that both factors affect the blood spot surface area, however, the positive effect of blood volume is higher than the negative effect of hematocrit. The measurement of surface area could be added as an additional quality control step in clinical studies that have adopted fixed volume DBS sampling for the quantification of the analytes. This approach can be used in estimating the hematocrit if this is not known for a patient or estimating the volume in spots that are visually different in size from the norm, i.e. technical error.
Space invaders: Searching for invasive Smallmouth Bass (Micropterus dolomieu) in a renowned Atlantic Salmon (Salmo salar) river
Authors: O'Sullivan Antóin M. , Samways Kurt M. , Perreault Alysse , Hernandez Cécilia , Gautreau Mark D. , Curry R. Allen , Bernatchez Louis
Published: February 2020

Humans have the ability to permanently alter aquatic ecosystems and the introduction of species is often the most serious alteration. Non‐native Smallmouth Bass (Micropterus dolomieu) were identified in Miramichi Lake c. 2008, which is a headwater tributary to the Southwest Miramichi River, a renowned Atlantic Salmon (Salmo salar) river whose salmon population is dwindling. A containment programme managed by the Department of Fisheries and Oceans, Canada (DFO) was implemented in 2009 to confine Smallmouth Bass (SMB) to the lake. We utilized environmental DNA (eDNA) as a detection tool to establish the potential escape of SMB into the Southwest Miramichi River. We sampled at 26 unique sites within Miramichi Lake, the outlet of Miramichi Lake (Lake Brook), which flows into the main stem Southwest Miramichi River, and the main stem Southwest Miramichi River between August and October 2017. We observed n = 6 positive detections located in the lake, Lake Brook, and the main stem Southwest Miramichi downstream of the lake. No detections were observed upstream of the confluence of Lake Brook and the main stem Southwest Miramichi. The spatial pattern of positive eDNA detections downstream of the lake suggests the presence of individual fish versus lake‐sourced DNA in the outlet stream discharging to the main river. Smallmouth Bass were later confirmed by visual observation during a snorkeling campaign, and angling. Our results, both eDNA and visual confirmation, definitively show Smallmouth Bass now occupy the main stem of the Southwest Miramichi.
Comparison of morphological, DNA barcoding, and metabarcoding characterizations of freshwater nematode communities
Authors: Schenk Janina , Kleinbölting Nils , Traunspurger Walter
Published: February 2020

Biomonitoring approaches and investigations of many ecological questions require assessments of the biodiversity of a given habitat. Small organisms, ranging from protozoans to metazoans, are of great ecological importance and comprise a major share of the planet's biodiversity but they are extremely difficult to identify, due to their minute body sizes and indistinct structures. Thus, most biodiversity studies that include small organisms draw on several methods for species delimitation, ranging from traditional microscopy to molecular techniques. In this study, we compared the efficiency of these methods by analyzing a community of nematodes. Specifically, we evaluated the performances of traditional morphological identification, single‐specimen barcoding (Sanger sequencing), and metabarcoding in the identification of 1500 nematodes from sediment samples. The molecular approaches were based on the analysis of the 28S ribosomal large and 18S small subunits (LSU and SSU). The morphological analysis resulted in the determination of 22 nematode species. Barcoding identified a comparable number of operational taxonomic units (OTUs) based on 28S rDNA (n = 20) and fewer OTUs based on 18S rDNA (n = 12). Metabarcoding identified a higher OTU number but fewer amplicon sequence variants (AVSs) (n = 48 OTUs, n = 17 ASVs for 28S rDNA, and n = 31 OTUs, n = 6 ASVs for 18S rDNA). Between the three approaches (morphology, barcoding, and metabarcoding), only three species (13.6%) were shared. This lack of taxonomic resolution hinders reliable community identifications to the species level. Further database curation will ensure the effective use of molecular species identification.
Operant conditioning as a new mechanism of placebo effects
Authors: Bąbel Przemysław
Published: February 2020

Background and Objective

Placebo effects are considered to be learning phenomena. There is a growing body of evidence supporting the role of both classical conditioning and observational learning in the induction of placebo effects. However, the third basic learning process, operant conditioning, was not considered as a mechanism of placebo effects until very recently. Unlike classically conditioned responses, which are induced by stimuli that precede the behaviour, operant behaviours are shaped and maintained by their consequences. Thus, placebo effects may not only result from pairing an active intervention with the stimuli that accompany its administration (placebo) but also positive (e.g. the ability to perform a desired activity) or negative reinforcement (e.g. pain relief) of placebo administration may increase the frequency of taking placebos in the future. The paper reviews the evidence supporting the idea of operant conditioning as a mechanism of placebo effects and discusses it in the context of the general principles of operant conditioning, the operant conditioning account of pain modulation and research findings on the role of operant conditioning in pain modulation.

Databases and Data Treatment

This is a narrative review.

Results

Seven lines of research are proposed to study the role of operant conditioning in producing placebo effects.

Conclusions

Operant conditioning account of placebo effects has practical implications both for routine clinical practice and the placebo arms of randomized controlled trials.

Significance

The operant conditioning account of placebo effects is discussed from the theoretical perspective of the general principles of operant conditioning and the operant conditioning account of pain modulation. The paper identifies seven lines of research on the role of operant conditioning in producing placebo effects, and highlights the practical implications of the operant conditioning account of placebo effects both for routine clinical practice and the placebo arms of randomized controlled trials.
Mn2+ or Mn3+? Investigating transition metal dissolution of manganese species in lithium ion battery electrolytes by capillary electrophoresis
Authors: Hanf Lenard , Henschel Jonas , Diehl Marcel , Winter Martin , Nowak Sascha
Published: February 2020

A new CE method with ultraviolet–visible detection was developed in this study to investigate manganese dissolution in lithium ion battery electrolytes. The aqueous running buffer based on diphosphate showed excellent stabilization of labile Mn3+, even under electrophoretic conditions. The method was optimized regarding the concentration of diphosphate and modifier to obtain suitable signals for quantification. Additionally, the finally obtained method was applied on carbonate‐based electrolytes samples. Dissolution experiments of the cathode material LiNi0.5Mn1.5O4 (lithium nickel manganese oxide [LNMO]) in aqueous diphosphate buffer at defined pH were performed to investigate the effect of a transition metal‐ion‐scavenger on the oxidation state of dissolved manganese. Quantification of both Mn species revealed the formation of mainly Mn3+, which can be attributed to a comproportionation reaction of dissolved and complexed Mn2+ with Mn4+ at the surface of the LNMO structure. It was also shown that the formation of Mn3+ increased with lower pH. In contrast, dissolution experiments of LNMO in carbonate‐based electrolytes containing LIPF6 showed only dissolution of Mn2+.
Study on the discrete dielectrophoresis for particle–cell separation
Authors: Techaumnat Boonchai , Panklang Nitipong , Wisitsoraat Anurat , Suzuki Yuji
Published: February 2020

This paper presents the application of the discrete dielectrophoretic force to separate polystyrene particles from red blood cells. The separation process employs a simple microfluidic device that is composed of interdigitated electrodes and a microchannel. The discrete dielectrophoretic force is generated by adjusting the duty cycle of the applied voltage. The electrodes make a tilt angle with the microchannel to change the moving direction of the red blood cells. By adjusting the voltage magnitude and duty cycle, we investigate the deflection of red blood cells and the variation of cell velocity along electrode edge under positive dielectrophoresis. The experiments with polystyrene particles show that the enrichment of the particles is greater than 150 times. The maximum separation efficiency is 97% for particle‐to‐cell number ratio equal to 1:2000 in the sample having high cell concentration. Using the appropriate applied voltage magnitude and duty cycle, the discrete dielectrophoretic force can prevent the clogging of microchannel while successfully separating the particles from the cells with high enrichment and efficiency. The proposed principle can be readily applied to dielectrophoresis‐based devices for biomedical sample preparation or diagnosis such as the separation of rare or infected cells from a blood sample.
Controllable Multistep Preparation Method for High‐Efficiency Perovskite Solar Cells with Low Annealing Temperature in Glove Box
Authors: Liu DeBei , Zeng QingXin , Yao YanQing , Liang HongFei , Chen LiJia , Song QunLiang
Published: February 2020

Perovskite solar cells (PeSCs) fabricated by a two‐step method have achieved high power conversion efficiency (PCE). Although two‐step fabrication makes the formation of perovskite films much easier to control, the too fast reaction between the lead source (such as PbI2) and halogenated organic/inorganic cation (such as formamidinium iodide [FAI]) during the high‐temperature (≈150 °C for FAPbI3) annealing hinders further reaction progress, leaving a large amount of unreacted lead source. This annealing in air is a mandatory step to achieve high‐quality perovskite films and then high‐efficiency devices with the aid of moisture, which is detrimental to device stability. Herein, a multistep preparation procedure (recoating FA0.9MA0.1I solution) is proposed to obtain a well‐defined perovskite film with large crystal domain size (≈ several micrometers) and reduced grain boundary at low annealing temperature without the help of moisture (i.e., 60 °C in glove box). As a result, a device with high PCE up to 19.301% is achieved using the multistep prepared perovskite film. The high‐quality perovskite film is attributed to the dissolution–recrystallization process during the repeated FA0.9MA0.1I coating procedure. The capability of this multistep method is further demonstrated in fabricating high‐performance devices (PCE of 17.762%) without the annealing procedure.
The Subacute Toxicity of Perfluorooctane Sulfonate and/or Perfluorooctanoic Acid and Legacy Aqueous Film-Forming Foams to Japanese Quail (Coturnix japonica) Chicks
Authors: Bursian Steven J. , Link Jane E. , McCarty Michael , Simcik Matt F.
Published: February 2020

As part of an effort to develop avian ecotoxicity information for poly- and perfluoroalkyl substances (PFAS) including perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) associated with aqueous film-forming foam (AFFF) used by the Department of Defense, the subacute toxicity of PFOS, PFOA, PFOS + PFOA, 3M AFFF, and Ansul AFFF to Japanese quail (Coturnix japonica) chicks was determined. Ten-day-old Japanese quail were administered treated feed for 5 d and then fed untreated feed for 18 d. Analyzed concentrations of PFOS, PFOA, and PFOS + PFOA ranged from 62 to 1955, 162 to 1208, and 43 + 45 to 296 + 292 mg kg feed–1. Analyzed concentrations of PFOS in feed containing the 3M AFFF ranged from 73 to 1399 mg kg feed–1, and formulated concentrations of 6:2 fluorotelomer thioamido sulfonate in feed containing the Ansul AFFF ranged from 9 to 1118 mg kg feed–1. Average daily doses resulting in 50% mortality at day 5 were 38 (34–43), 68 (63–74), 55 (51–59), and 130 (103–164) mg PFOS, PFOA, PFOS + PFOA, and PFOS in 3M AFFF kg body weight–1 d–1. Ansul AFFF did not result in any mortalities. Dietary concentrations resulting in 50% mortality at day 5 were 351 (275–450), 496 (427–575), 398 (339–468), and 467 (390–559) mg PFOS, PFOA, PFOS + PFOA, and PFOS in 3M AFFF kg feed–1. Environ Toxicol Chem 2021;40:695–710. © 2020 SETAC
Mitochondrial division inhibitor 1 disrupts oligodendrocyte Ca2+ homeostasis and mitochondrial function
Authors: Ruiz Asier , Quintela‐López Tania , Sánchez‐Gómez María V. , Gaminde‐Blasco Adhara , Alberdi Elena , Matute Carlos
Published: February 2020

Mitochondrial fission mediated by cytosolic dynamin related protein 1 (Drp1) is essential for mitochondrial quality control but may contribute to apoptosis as well. Blockade of Drp1 with mitochondrial division inhibitor 1 (mdivi‐1) provides neuroprotection in several models of neurodegeneration and cerebral ischemia and has emerged as a promising therapeutic drug. In oligodendrocytes, overactivation of AMPA‐type ionotropic glutamate receptors (AMPARs) induces intracellular Ca2+ overload and excitotoxic death that contributes to demyelinating diseases. Mitochondria are key to Ca2+ homeostasis, however it is unclear how it is disrupted during oligodendroglial excitotoxicity. In the current study, we have analyzed mitochondrial dynamics during AMPAR activation and the effects of mdivi‐1 on excitotoxicity in optic nerve‐derived oligodendrocytes. Sublethal AMPAR activation triggered Drp1‐dependent mitochondrial fission, whereas toxic AMPAR activation produced Drp1‐independent mitochondrial swelling. Accordingly, mdivi‐1 efficiently inhibited Drp1‐mediated mitochondrial fission and did not prevent oligodendrocyte excitotoxicity. Unexpectedly, mdivi‐1 also induced mitochondrial depolarization, ER Ca2+ depletion and modulation of AMPA‐induced Ca2+ signaling. These off‐target effects of mdivi‐1 sensitized oligodendrocytes to excitotoxicity and ER stress and eventually produced oxidative stress and apoptosis. Interestingly, in cultured astrocytes mdivi‐1 induced nondetrimental mitochondrial depolarization and oxidative stress that did not cause toxicity or sensitization to apoptotic stimuli. In summary, our results provide evidence of Drp1‐mediated mitochondrial fission during activation of ionotropic glutamate receptors in oligodendrocytes, and uncover a deleterious and Drp1‐independent effect of mdivi‐1 on mitochondrial and ER function in these cells. These off‐target effects of mdivi‐1 limit its therapeutic potential and should be taken into account in clinical studies.
Convergence of distinct functional networks supporting naming and semantic recognition in the left inferior frontal gyrus
Authors: Xu Zhansheng , Shen Bo , Taji Wael , Sun Pei , Naya Yuji
Published: February 2020

Naming individual objects is accompanied with semantic recognition. Previous studies examined brain‐networks responsible for these operations individually. However, it remains unclear how these brain‐networks are related. To address this problem, we examined the brain‐networks during a novel object‐naming task, requiring participants to name animals in photographs at a specific‐level (e.g., “pigeon”). When the participants could not remember specific names, they answered basic names (e.g., “bird”). After fMRI scanning during the object‐naming task, the participants rated familiarity of the animals based on their sense of knowing. Since participants tend to remember specific names for familiar objects compared with unfamiliar objects, a typical issue in an object‐naming task is an internal covariance between the naming and familiarity levels. We removed this confounding factor by adjusting the familiarity/naming level of stimuli, and demonstrated distinct brain regions related to the two operations. Among them, the left inferior frontal gyrus triangularis (IFGtri) contained object‐naming and semantic‐recognition related areas in its anterior‐ventral and posterior‐dorsal parts, respectively. Psychophysiological interaction analyses suggested that both parts show connectivity with the brain regions related to object‐naming. By examining the connectivity under control tasks requiring nonlexical semantic retrieval (e.g., animal's body color), we found that both IFGtri parts altered their targeting brain areas according to the required memory attributes, while only the posterior‐dorsal part connected the brain regions related to semantic recognition. Together, the semantic recognition may be processed by distinct brain network from those for voluntary semantic retrievals including object‐naming although all these networks are mediated by the posterior‐dorsal IFGtri.
Estrogen Acts Through Estrogen Receptor 2b to Regulate Hepatobiliary Fate During Vertebrate Development
Authors: Chaturantabut Saireudee , Shwartz Arkadi , Garnaas Maija K. , LaBella Kyle , Li Chia‐Cheng , Carroll Kelli J. , Cutting Claire C. , Budrow Nadine , Palaria Amrita , Gorelick Daniel A. , Tremblay Kimberly D. , North Trista E. , Goessling Wolfram
Published: February 2020

Background and Aims

During liver development, bipotent progenitor cells differentiate into hepatocytes and biliary epithelial cells to ensure a functional liver required to maintain organismal homeostasis. The developmental cues controlling the differentiation of committed progenitors into these cell types, however, are incompletely understood. Here, we discover an essential role for estrogenic regulation in vertebrate liver development to affect hepatobiliary fate decisions.

Approach and Results

Exposure of zebrafish embryos to 17β‐estradiol (E2) during liver development significantly decreased hepatocyte‐specific gene expression, liver size, and hepatocyte number. In contrast, pharmacological blockade of estrogen synthesis or nuclear estrogen receptor (ESR) signaling enhanced liver size and hepatocyte marker expression. Transgenic reporter fish demonstrated nuclear ESR activity in the developing liver. Chemical inhibition and morpholino knockdown of nuclear estrogen receptor 2b (esr2b) increased hepatocyte gene expression and blocked the effects of E2 exposure. esr2b−/−
mutant zebrafish exhibited significantly increased expression of hepatocyte markers with no impact on liver progenitors, other endodermal lineages, or vasculature. Significantly, E2‐stimulated Esr2b activity promoted biliary epithelial differentiation at the expense of hepatocyte fate, whereas loss of esr2b impaired biliary lineage commitment. Chemical and genetic epistasis studies identified bone morphogenetic protein (BMP) signaling as a mediator of the estrogen effects. The divergent impact of estrogen on hepatobiliary fate was confirmed in a human hepatoblast cell line, indicating the relevance of this pathway for human liver development.

Conclusions

Our studies identify E2, esr2b, and downstream BMP activity as important regulators of hepatobiliary fate decisions during vertebrate liver development. These results have significant clinical implications for liver development in infants exposed to abnormal estrogen levels or estrogenic compounds during pregnancy.