bluuebunny/crossref_metadata_2025 huggingface dataset:
Extending the Tunable Plasma Wavelength in III–V Semiconductors from the Mid‐Infrared to the Short‐Wave Infrared by Embedding Self‐Assembled ErAs Nanostructures in GaAs
Authors: Wang Yuejing , Wei Dongxia , Sohr Patrick , Zide Joshua M. O. , Law Stephanie
Published: January 2020

The group III–V semiconductor photonic system is attractive to photonics engineers because it provides a complete set of photonic components. A plasmonic material that can be epitaxially integrated with the group III–V photonic system will potentially lead to many applications leveraging plasmonics and metamaterials. In this work, the shortest plasma wavelength ever reported in a III–V‐based material is demonstrated by epitaxially embedding ErAs into GaAs. This composite material acts as a tunable plasmonic material across the technologically important 2.68–6 µm infrared window. The growth window of this material is demonstrated to be much wider than other current heavily doped III–V plasmonic materials. Additionally, it is shown that the scattering rate can be reduced by increasing the growth temperature. The wide growth temperature range, designer plasmonic response, and the ease of epitaxial integration with other III–V semiconductor devices demonstrate the potential of ErAs:GaAs nanocomposites for the creation of a new type of metamaterial and other novel optoelectronic and nanophotonic applications.
Strong Dispersive Propagation of Terahertz Wave: Time‐Domain Self‐Consistent Modeling of Metallic Wall Losses
Authors: Gao Zi‐Chao , Du Chao‐Hai , Li Fan‐Hong , Pan Shi , Zhang Zi‐Wen , Liu Pu‐Kun
Published: January 2020

The dispersion characteristics of electromagnetic waves have led to a wide range of applications, such as pulse compression, superluminal propagation, wave tunneling effect, and electron–wave interaction. The near‐cutoff wave inside a guiding system is strong dispersive. When the wave frequency reaches the terahertz band, this strong dispersive property is extremely sensitive to the losses induced by the limited conductivity of the component. This phenomenon is traditionally investigated through perturbation of boundary conditions in the frequency domain, which does not deal well with broad‐spectrum signals. Two simple and efficient time‐domain schemes to study the strong dispersive propagation of terahertz waves are proposed. One is based on relatively concise principles, called the constant frequency method. The second is the recursive convolution method, which is suitable for dealing with a wave with wider spectrum range. The reliability of both approaches is verified by the comparison of the dispersion curves. Using the proposed methods, the pulse compression of terahertz wave inside a strong dispersive waveguide is verified in principle.
Adult Tissue Extracellular Matrix Determines Tissue Specification of Human iPSC‐Derived Embryonic Stage Mesodermal Precursor Cells
Authors: Ullah Imran , Busch Jonas Felix , Rabien Anja , Ergün Bettina , Stamm Christof , Knosalla Christoph , Hippenstiel Stefan , Reinke Petra , Kurtz Andreas
Published: January 2020

The selection of pluripotent stem cell (PSC)‐derived cells for tissue modeling and cell therapy will be influenced by their response to the tissue environment, including the extracellular matrix (ECM). Whether and how instructive memory is imprinted in adult ECM and able to impact on the tissue specific determination of human PSC‐derived developmentally fetal mesodermal precursor (P‐meso) cells is investigated. Decellularized ECM (dECM) is generated from human heart, kidney, and lung tissues and recellularized with P‐meso cells in a medium not containing any differentiation inducing components. While P‐meso cells on kidney dECM differentiate exclusively into nephronal cells, only beating clusters containing mature and immature cardiac cells form on heart dECM. No tissue‐specific differentiation of P‐meso cells is observed on endoderm‐derived lung dECM. P‐meso‐derived endothelial cells, however, are found on all dECM preparations independent of tissue origin. Clearance of heparan‐sulfate proteoglycans (HSPG) from dECM abolishes induction of tissue‐specific differentiation. It is concluded that HSPG‐bound factors on adult tissue‐derived ECM are essential and sufficient to induce tissue‐specific specification of uncommitted fetal stage precursor cells.
An Enzyme‐Mimicking Single‐Atom Catalyst as an Efficient Multiple Reactive Oxygen and Nitrogen Species Scavenger for Sepsis Management
Authors: Cao Fangfang , Zhang Lu , You Yawen , Zheng Lirong , Ren Jinsong , Qu Xiaogang
Published: January 2020

Sepsis, characterized by immoderate production of multiple reactive oxygen and nitrogen species (RONS), causes high morbidity and mortality. Despite progress made with nanozymes, efficient antioxidant therapy to eliminate these RONS remains challenging, owing largely to the specificity and low activity of exploited nanozymes. Herein, an enzyme‐mimicking single‐atom catalyst, Co/PMCS, features atomically dispersed coordinatively unsaturated active Co‐porphyrin centers, which can rapidly obliterate multiple RONS to alleviate sepsis. Co/PMCS can eliminate O2.− and H2O2 by mimicking superoxide dismutase, catalase, and glutathione peroxidase, while removing .OH via the oxidative‐reduction cycle, with markedly higher activity than nanozymes. It can also scavenge .NO through formation of a nitrosyl–metal complex. Eventually, it can reduce proinflammatory cytokine levels, protect organs from damage, and confer a distinct survival advantage to the infected sepsis mice.
Controllable Synthesis of Graphdiyne Nanoribbons
Authors: Zhou Weixiang , Shen Han , Zeng Yan , Yi Yuanping , Zuo Zicheng , Li Yongjun , Li Yuliang
Published: January 2020

Graphdiyne nanoribbons with high chemical precision are of great significance for further understanding of the intrinsic properties of graphdiyne and the relationship between structure and properties. However, the reliable synthesis of graphdiyne nanoribbons with chemical precision remains a significant challenge. A facile method is now presented for fabrication of graphdiyne nanoribbons with uniform width through stepwise inter‐ and intramolecular Glaser–Hay coupling reaction of ethynyl groups. The synthetic ribbons were interwoven into nanotextiles by π–π stacking and were applied for protective coating of Li‐electrode in Li‐ion batteries, which efficiently suppressed the growth of the Li dendrites during cycling and prolonged the life span of Li‐metal batteries.
An unprecedented transformation mode in aluminium oxazoline‐amido‐phenolate complexes
Authors: Chen Ming‐Tsz , Chen Yu‐Yang , Li Guan‐Lin , Chou Kai‐Wen , Hu Ching‐Han , Huang Guo‐Cyuan , Chen Chi‐Tien
Published: January 2020

This paper describes the effect of solvent‐induced synthetic routes of aluminium pendant oxazoline‐amido‐phenolate complexes. Treatment of ligand precursor L with AlMe3 in a 1:1 ratio in diethyl ether yielded the four‐coordinated complex (LAlMe)2. Reaction of ligand precursor L with AlMe3 in a 1:2 ratio in hexane generated the four‐coordinated complex L(AlMe2)2. A novel transformation mode occurred from L(AlMe2)2 to (LAlMe)2 when using diethyl ether or tetrahydrofuran as solvent. A density functional theory computational study also supports a plausible mechanism. All results were supported by spectroscopic data and in agreement with single‐crystal X‐ray diffraction structural analysis.
Dinuclear Zn(II) and tetranuclear Co(II) complexes of a tetradentate N2O2 Schiff base ligand: Synthesis, crystal structure, characterization, DFT studies, cytotoxicity evaluation, and catalytic activity toward benzyl alcohol oxidation
Authors: Sanatkar Tahereh Hosseinzadeh , Khorshidi Alireza , Janczak Jan
Published: January 2020

Two novel dinuclear Zn(II) and tetranuclear Co(II) complexes of a tetradentate N2O2 Schiff base ligand (H2L = N,N′‐bis‐(4‐hydroxysalicylidene)‐1,3‐diaminopropane) were prepared. The structures of the H2L ligand, [4(Zn2L(μ‐O2CCH3)(O2CCH3)(H2O))]⋅4CH3OH⋅3H2O (complex 1) and [Co4L2(μ‐O2CCH3)2(O2CCH3)2]⋅2H2O (complex 2) were unambiguously characterized by elemental analysis, mass spectrometry, Fourier‐transform infrared spectroscopy (FT‐IR), 1H nuclear magnetic resonance (NMR), and UV–Vis spectroscopy. Single crystal X‐ray diffraction studies revealed that two Zn(II) nuclei of 1 were connected through μ‐phenolato and μ‐acetato bridges and had distorted square pyramidal and distorted octahedral coordination geometries. Four Co(II) nuclei of 2, on the contrary, showed a Co4O4 cubane‐like configuration in which Co(II) cations and O atoms were located at alternating corners of a distorted cube. Density functional theory studies at the B3LYP/6–31 G(d) level were carried out to gain an insight into the thermodynamic stability of the complexes. in vitro cytotoxicity of the ligand and the complexes were evaluated using the MTT assay against breast cancer MCF7 cells, melanoma cancer A375 cells, and prostate cancer PC3 cells as representative human cancer cell lines. Complex 1 showed a remarkable activity against A375 and PC3 cancer cell lines. In addition, 1 and 2 were used as precursors to produce zinc and cobalt oxide nanoparticles via pyrolysis technique. The resulting ZnO and Co3O4 nanoparticles were characterized using FT‐IR spectroscopy, UV–Vis diffuse reflectance spectroscopy, powder X‐ray diffraction, and field emission scanning electron microscopy. Then, these nanoparticles were used as heterogeneous catalysts in the oxidation of benzyl alcohol with hydrogen peroxide at room temperature. Both catalysts showed good recyclability with a negligible decrease in their efficiency during four catalytic cycles. The results of theoretical calculations showed that the most stable product was benzaldehyde, which is in good agreement with the obtained experimental results.
Structure and electrically conductive properties of porous PAN‐based nanocomposites prepared by Pickering emulsion template method
Authors: Wang Baichen , Dou Shuo , Gao Yu , Li Wei
Published: January 2020

A carbon nanohybrid Pickering stabilizer was synthesized by the hydrothermal reaction of 2‐ethyl‐4‐methylimidazole (EMI), graphene oxide (GO), and carbon nanotubes (CNTs). A water‐in‐oil (w/o) type Pickering emulsion was achieved using the mixed carbon nanohybrids/Span 80 to form a porous and conductive polyacrylonitrile (PAN) nanocomposites after polymerization. Contact angle and X‐ray photoelectron spectroscopy (XPS) results show that the carbon nanohybrid stabilizer is amphiphilic. The effects of the composition and concentration of stabilizers were investigated. When the concentration of the carbon nanohybrid stabilizer is 4 mg ml−1, the conductivity of the resulting material is 2.31 × 10−9 S m−1, which is six orders of magnitude higher than that of porous PAN composites without carbon nanohybrid stabilizer. At the mass ratio of 6GO:1CNTs, the conductivity of porous PAN‐based composites reaches 2.47 × 10−8 S m−1. The significantly increased conductivity is the evidence for the three dimensional conductive network constructed by carbon nanohybrid stabilizer at the oil/water interface.
Polymers of vinylphosphonic acid, acrylonitrile, and methyl acrylate and their nanofibers
Authors: Yılmaz Mustafa , Akar Ahmet , Köken Nesrin , Kızılcan Nilgün
Published: January 2020

In this study, a small amount of vinylphosphonic acid was used to produce fire‐retardant copolymers and terpolymers from acrylonitrile and methyl acrylate. The structures of copolymer and terpolymers were elucidated by 1H‐NMR and phosphorous analysis. Thermal decomposition of vinylphosphonic acid‐containing copolymers and terpolymers started at lower temperatures than of poly(acrylonitrile‐co‐methyl acrylate). Methyl acrylate contributes to the thermal resistance of the terpolymers. Poly(acrylonitrile‐co‐methyl acrylate‐co‐vinylphosphonic acid) with a phosphorous content about 0.25% burned at a slower rate and emitted less smoke compared to poly(acrylonitrile‐co‐methyl acrylate). The burning tests showed that both copolymer and terpolymers containing vinylphosphonic acid behaved as a fire‐retardant polymer. The phosphonate and phosphonic acid groups in the copolymer and terpolymers accelerate the cyclization of nitrile groups and inhibit the fire in the gas phase. Nanofibers were successfully produced by the electrospinning method from the copolymers and terpolymers containing vinylphosphonic acid moiety.
The diving behaviour of little penguins in Western Australia predisposes them to risk of injury by watercraft
Authors: Cannell Belinda , Ropert‐Coudert Yan , Radford Ben , Kato Akiko
Published: January 2020

The most western little penguin colony globally, and the most northern in Western Australia (WA) is found on Penguin Island, WA. The penguins use coastal bays that are also used extensively by recreational watercraft. These penguins have been found to either dive predominantly to shallow depths of 1–5 m or to depths >8 m. It is thus hypothesized that (a) both the shallow and deeper diving penguins can potentially be disturbed or injured by these watercraft but that the risk will differ between the two diving strategies, and (b) that risk of injury for both is greater during the summer and autumn, when people are more likely to use watercraft.

This was tested by attaching data loggers to little penguins during chick rearing and by investigating necropsy records. Diving activity was studied for the very shallow and relatively deeper diving penguins separately, and we considered the penguins were vulnerable to interactions with watercraft when they were within the top 2 m of the water column or at the surface.

Shallow‐diving penguins executed >1,200 dives per day, 64% of dives occurred within the top 2 m, and they were vulnerable for approximately two‐thirds of their time at sea. The deeper diving penguins executed fewer dives. Almost half of dives were to ≥10 m, yet they were vulnerable for almost one‐third of their time at sea. Their post‐dive recovery was also longer. Thus, the risk of interaction from watercraft differs depending on the diving behaviour.

This study highlights the potential impact to little penguins throughout Australia and New Zealand.
The Yığma Tepe of Pergamon: stratigraphic construction of a monumental tumulus from seismic refraction measurements
Authors: Mecking Rebekka , Meinecke Matthias , Erkul Ercan , Driehaus Birte , Bolten Andreas , Pirson Felix , Rabbel Wolfgang
Published: January 2020

The monumental tumulus Yığma Tepe is an important part of the cityscape of the ancient city of Pergamon. The tumulus construction is estimated in the Hellenistic period, the internal structure and exact purpose have been unknown so far. Its height of 32 m and diameter of 158 m make the deep interior of the tumulus practically inaccessible for excavations. Therefore, we applied a combination of geophysical measurements and archaeological sondages to explore the structure of the Yığma Tepe. The investigations centre on P‐wave refraction soundings. They were carried out to clarify the stratigraphic structure and soil composition as a prerequisite for a better understanding of construction techniques, building history and soil deposition. Interactive seismic raytracing, traveltime tomography and visco‐elastic forward modelling were applied to derive a three‐dimensional seismic velocity model, which was validated by excavations and soil analysis, historical records and additional geoelectric measurements. Our results reveal that the tumulus is composed of three layers, each about 10 m thick, separated by first‐order seismic discontinuities which were locally verified. These layers form a stack of conical disks, the interfaces of which define two internal plateaus. The analysis of soil samples showed that the seismic velocity increase at the interfaces is likely to be caused by anthropogenic compaction applied to soils showing increased fractions of silt and clay. By combining topographic data with results from seismic and geoelectric sounding on the tumulus, the surrounding trench and the unaltered surrounding area, we show that the tumulus was built almost completely from the surrounding soils and that 17% of its original volume was displaced by destruction and erosion. Based on this mass balance the strongly destroyed and eroded original surface of the tumulus and its surrounding trench is reconstructed.
The Incredible Years Autism Spectrum and Language Delays Parent Program: A Pragmatic, Feasibility Randomized Controlled Trial
Authors: Williams Margiad E. , Hastings Richard P. , Hutchings Judy
Published: January 2020

Behavior problems in children with autism spectrum disorders (ASD) are common and particularly stressful for parents. This study aimed to examine the feasibility of delivering a parenting program in existing services, and the feasibility of conducting a future large‐scale Randomized Controlled Trial evaluation of the effectiveness of the intervention. Parents of children aged 3–8 years with a diagnosis of ASD, or strongly suspected ASD were eligible to participate. A multicenter, pragmatic, feasibility randomized controlled trial was conducted in four specialist children's services in Wales. Families were randomly assigned to receive the Incredible Years® Autism Spectrum and Language Delays (IY‐ASLD) parent program immediately or to a wait‐list, treatment as usual control condition. IY‐ASLD sessions were delivered once a week for 12 weeks. The primary outcomes related to feasibility (recruitment, retention, fidelity, and acceptability). Preliminary outcome analyses were conducted using covariance models controlling for study site and baseline scores. From October 5 to December 19, 2016, 58 families were randomized, 29 to IY‐ASLD and 29 to control. Three parents did not attend any sessions while 19 (73%) completed the program. Fidelity of delivery was high (88%), as was satisfaction with the program. Fifty‐three (91%) completed the follow‐up measures. All 95% CIs for effect sizes included zero in exploratory outcome analyses. This study supports the feasibility of delivering the IY‐ASLD in existing services with good levels of acceptability and fidelity evident. A larger randomized controlled trial is required to examine the effectiveness of the program. Autism Res 2020, 13: 1011‐1022. © 2020 International Society for Autism Research, Wiley Periodicals, Inc.

Lay Summary

This study examined the feasibility and acceptability of delivering a parenting program for parents of children aged 3–8 years with Autism Spectrum Disorder in existing child services. Recruitment and retention in the study were good and parents rated all aspects of the program positively. Practitioners were able to deliver the program as intended and the measures used for program outcomes were appropriate. A larger study to examine program effectiveness would be feasible.
Rational application of targeted therapeutics in mucinous colon/appendix cancers with positive predictive factors
Authors: Dilly Ashokkumar , Honick Brendon D. , Lee Yong J. , Bartlett David L. , Choudry Haroon A.
Published: January 2020

Molecular‐targeted therapies have demonstrated disappointing results against most advanced solid cancers. This may largey be attributed to irrational drug use against unselected cancers. We investigated the efficacy of dual MEK‐PI3K drug therapy against KRAS mutated mucin 2 (MUC2)‐secreting LS174T cells and patient‐derived ex vivo and in vivo models of KRAS mutated mucinous colon/appendix cancers. These tumors demonstrate unique phenotypic and genotypic features that likely predict sensitivity to this targeted co‐therapy. Co‐treatment with MEK inhibitor (trametinib) and PI3K inhibitor (pictilisib)‐induced synergistic cytotoxicity and intrinsic mitochondrial‐mediated apoptosis in LS174T cells and tumor explants in vitro. Dual drug therapy also induced endoplasmic reticulum stress (ERS)‐associated proteins (GRP78/BiP, ATF4, and CHOP). However, CHOP knock‐down assays demonstrated that mitochondrial‐mediated apoptosis in LS174T cells was not ERS‐dependent. Dual drug therapy also significantly decreased MUC2 expression, MUC2 post‐translational modification (palmitoylation) and secretion in LS174T cells, suggesting a simultaneous cytotoxic and mucin suppressive mechanism of action. We also demonstrated effective mucinous tumor growth suppression in ex vivo epithelial organoid (colonoid) cultures and in in vivo intraperitoneal patient‐derived xenograft models derived from mucinous colon/appendix cancer. These promising preclinical data support a role for dual MEK‐PI3K inhibitor therapy in mucinous colon/appendix cancers. We postulate that mucinous KRAS mutated cancers are especially vulnerable to this co‐treatment based on their unique phenotypic and genotypic characteristics.
Selective Hydrogenation of Xylose to Xylitol over Co/SiO2 Catalysts
Authors: Audemar Maïté , Ramdani Wahiba , Junhui Tang , Raluca Ifrim Andreea , Ungureanu Adrian , Jérôme François , Royer Sébastien , de Oliveira Vigier Karine
Published: January 2020

Xylose can be selectively converted to xylitol in water, with an optimized yield of 98 %, in the presence of a simple silica supported monometallic cobalt – Co/SiO2 – catalyst. This catalyst displays initial outstanding catalytic properties in a proper solvent, the best results being obtained in pure water. Recyclability studies show a moderate deactivation of the catalyst, while selectivity to xylitol remains almost unchanged after 4 cycles, confirming that this catalyst formulation is very promising for the xylitol production process.
The Route from the Folded to the Amyloid State: Exploring the Potential Energy Surface of a Drug‐Like Miniprotein
Authors: Taricska Nóra , Horváth Dániel , Menyhárd Dóra K. , Ákontz‐Kiss Hanna , Noji Masahiro , So Masatomo , Goto Yuji , Fujiwara Toshimichi , Perczel András
Published: January 2020

Invited for the cover of this issue is the group of András Perczel at Eötvös Loránd University, Budapest, Hungary and colleagues from Osaka University, Japan. The image depicts the amyloid buildup of an Exenatide derivate miniprotein (E5) monitored on a simplified hyperspace. Read the full text of the article at 10.1002/chem.201903826.
Do all mammals dream?
Authors: Manger Paul R. , Siegel Jerome M.
Published: January 2020

The presence of dreams in human sleep, especially in REM sleep, and the detection of physiologically similar states in mammals has led many to ponder whether animals experience similar sleep mentation. Recent advances in our understanding of the anatomical and physiological correlates of sleep stages, and thus dreaming, allow a better understanding of the possibility of dream mentation in nonhuman mammals. Here, we explore the potential for dream mentation, in both non‐REM and REM sleep across mammals. If we take a hard‐stance, that dream mentation only occurs during REM sleep, we conclude that it is unlikely that monotremes, cetaceans, and otariid seals while at sea, have the potential to experience dream mentation. Atypical REM sleep in other species, such as African elephants and Arabian oryx, may alter their potential to experience REM dream mentation. Alternatively, evidence that dream mentation occurs during both non‐REM and REM sleep, indicates that all mammals have the potential to experience dream mentation. This non‐REM dream mentation may be different in the species where non‐REM is atypical, such as during unihemispheric sleep in aquatic mammals (cetaceans, sirens, and Otariid seals). In both scenarios, the cetaceans are the least likely mammalian group to experience vivid dream mentation due to the morphophysiological independence of their cerebral hemispheres. The application of techniques revealing dream mentation in humans to other mammals, specifically those that exhibit unusual sleep states, may lead to advances in our understanding of the neural underpinnings of dreams and conscious experiences.
Psychological interventions for depression and anxiety in pregnant Latina and Black women in the United States: A systematic review
Authors: Ponting Carolyn , Mahrer Nicole E. , Zelcer Hannah , Dunkel Schetter Christine , Chavira Denise A.
Published: January 2020

Black women and Latinas have more symptoms of depression and anxiety during pregnancy than do their non‐Latina White counterparts. Although effective interventions targeting internalizing disorders in pregnancy are available, they are primarily tested with White women. This article reviews randomized controlled trials and non‐randomized studies to better understand the effectiveness of psychological interventions for anxiety and depression during pregnancy in Latinas and Black women. Additionally, this review summarizes important characteristics of interventions such as intervention format, treatment modality, and the use of cultural adaptations. Literature searches of relevant research citation databases produced 68 studies; 13 of which were included in the final review. Most studies were excluded because their samples were not majority Latina or Black women or because they did not test an intervention. Of the included studies, three interventions outperformed a control group condition and showed statistically significant reductions in depressive symptoms. An additional two studies showed reductions in depressive symptoms from pretreatment to post‐treatment using non‐controlled designs. The remaining eight studies (seven randomized and one non‐randomized) did not show significant intervention effects. Cognitive behavioral therapy was the modality with most evidence for reducing depressive symptoms in pregnant Black and Latina women. No intervention was found to reduce anxiety symptoms, although only two of the 13 measured anxiety as an outcome. Five studies made cultural adaptations to their treatment protocols. Future studies should strive to better understand the importance of cultural modifications to improve engagement and clinical outcomes with pregnant women receiving treatment for anxiety and depression.
An efficient actor‐critic reinforcement learning for device‐to‐device communication underlaying sectored cellular network
Authors: Khuntia Pratap , Hazra Ranjay , Chong Peter
Published: January 2020

In this paper, a novel reinforcement learning (RL) approach with cell sectoring is proposed to solve the channel and power allocation issue for a device‐to‐device (D2D)‐enabled cellular network when the prior traffic information is not known to the base station (BS). Further, this paper explores an optimal policy for resource and power allocation between users intending to maximize the sum‐rate of the overall system. Since the behavior of wireless channel and traffic request of users in the system is stochastic in nature, the dynamic property of the environment allows us to employ an actor‐critic RL technique to learn the best policy through continuous interaction with the surrounding. The proposed work comprises of four phases: cell splitting, clustering, queuing model, and channel allocation and power allocation simultaneously using an actor‐critic RL. The implementation of cell splitting with novel clustering technique increases the network coverage, reduces co‐channel cell interference, and minimizes the transmission power of nodes, whereas the queuing model solves the issue of waiting time for users in a priority‐based data transmission. With the help of continuous state‐action space, the actor‐critic RL algorithm based on policy gradient improves the overall system sum‐rate as well as the D2D throughput. The actor adopts a parameter‐based stochastic policy for giving continuous action while the critic estimates the policy and criticizes the actor for the action. This reduces the high variance of the policy gradient. Through numerical simulations, the benefit of our resource sharing scheme over other existing traditional scheme is verified.
Lianas reduce biomass accumulation in early successional tropical forests
Authors: Estrada‐Villegas Sergio , Hall Jefferson S. , van Breugel Michiel , Schnitzer Stefan A.
Published: January 2020

Early successional tropical forests could mitigate climate change via rapid accumulation of atmospheric carbon. However, liana (woody vine) abundance and biomass has been increasing in many tropical forests over the past decades, which may slow the speed at which secondary forests accumulate biomass. Lianas decrease biomass accumulation in tropical forests, and may have a particularly strong effect on young forests by stalling tree growth. As forests mature, trees may outgrow or shed lianas, thus escaping some of the negative effects of lianas. Alternatively, lianas may have the strongest effect in older successional forests if the effect of lianas is commensurate with their density, which increases dramatically in the first decades of forest succession. We tested these two hypotheses using a landscape liana‐removal experiment in 30 forest stands that ranged from 10 to 35 yr old in Central Panama. We measured tree growth and biomass accumulation in the stands every year from 2014 to 2017. We found that the effect of liana removal on large trees (≥20‐cm diameter) decreased with forest age, supporting the hypothesis that lianas have the strongest negative effects on trees, and thus biomass uptake and carbon storage, in very young successional forests. Large trees accumulated more biomass in the absence of lianas in younger forests than in older forests (compared to controls) even after accounting for the effect of canopy completeness and crown illumination, implying that the detrimental effects of lianas go well beyond resource availability and crown health. There was no significant effect of lianas on small trees (1–20‐cm diameter), likely because lianas seek light and thus do not deploy their leaves on small trees that are trapped in the forest understory. Our results show that high liana density early in forest succession reduces forest biomass accumulation by negatively impacting large trees, thus decreasing the capacity of young secondary forests to mitigate climate change. Although the negative effects of lianas on forest biomass diminish as forests age, they do not disappear, and thus lianas are an important component of tropical forest carbon budgets throughout succession.
The optimization of fermentation conditions for Pichia pastoris GS115 producing recombinant xylanase
Authors: Sun Taotao , Yan Ping , Zhan Na , Zhang Licong , Chen Zhihui , Zhang Aizhong , Shan Anshan
Published: January 2020

Xylanase is a member of an important family of enzymes that has been used in many biotechnological processes. However, the overall cost of enzyme production has been the main problem in the industrial application of enzymes. To obtain maximum xylanase production, statistical approaches based on the Plackett–Burman design and response surface methodology were employed. The results of the statistical analyses demonstrated that the optimal conditions for increased xylanase production were the following: inoculum size, 3.8%; maize meal, 4.5%; histidine, 0.6%; methanol, 1%; culture volume, 20%; bean pulp, 30 g L−1; and Tween‐80, 0.8%; and pH 5.0. Verification of the optimization demonstrated that 3273 U mL−1 xylanase was observed under the optimal conditions in shake flask experiments. SDS–PAGE results showed that the size of xylanase protein was about 23 kDa. The results showed that the xylanase produced by fermentation came from Aspergillus Niger by MALDI‐TOF‐MS. The optimized medium resulted in 2.1‐ and 1.4‐fold higher the activity of xylanase compared with the unoptimized medium (the main nutrients are maize meal and bean pulp) and laboratory medium (the main nutrients are yeast extract and peptone), respectively. The optimization of fermentation conditions is an effective means to reduce production cost and improve xylanase activity.
Moving average threshold heterogeneous autoregressive (MAT‐HAR) models
Authors: Motegi Kaiji , Cai Xiaojing , Hamori Shigeyuki , Xu Haifeng
Published: January 2020

We propose moving average threshold heterogeneous autoregressive (MAT‐HAR) models as a novel combination of heterogeneous autoregression (HAR) and threshold autoregression (TAR). The MAT‐HAR has multiple groups of lags of a target series, and a threshold term can appear in each group. The threshold is a moving average of lagged target series, which guarantees time‐varying thresholds and simple estimation via least squares. We show via Monte Carlo simulations that the MAT‐HAR has sharp in‐sample and out‐of‐sample performance. An empirical application on the industrial production of Japan suggests that significant threshold effects exist, and the MAT‐HAR has a higher forecast accuracy than the HAR.
A Gap in the Armor: Spearfishing Reduces Biomass of Invasive Suckermouth Armored Catfish
Authors: Blanton Caleb S , Perkin Joshuah S , Menchaca Nick , Kollaus Kristy A
Published: January 2020

Introduced Suckermouth Armored Catfish (SAC; family Loricariidae) have invaded freshwater ecosystems globally. In the San Marcos River, Texas, control of invasive SAC includes spearfishing through public tournaments and contracted spearfishing, yet the effectiveness of these control efforts is unquantified. We used a recently developed length-based Bayesian biomass estimation method to assess spearfishing mortality relative to natural mortality and existing biomass relative to an unexploited population. During 2014–2018, 6,046 SAC were removed and measured (total length, cm) from the San Marcos River through spearfishing. Using the length-based Bayesian biomass, we found fishing pressure increased mortality 1.50- to 1.75-fold relative to natural mortality, and that relative biomass during 2016–2018 was significantly below the threshold at which stock depletion occurs. Our application of fishery stock assessment provides quantitative benchmarks for invasive species control and can be applied to other invaded systems where control methods are unassessed but length data from removed individuals are available.
Role of fucosyltransferase IV in the migration and invasion of human melanoma cells
Authors: Shan Xiu , Dong Weijie , Zhang Li , Cai Xin , Zhao Yi , Chen Qun , Yan Qiu , Liu Jiwei
Published: January 2020

Malignant melanoma is one of the most aggressive human tumor types, mainly due to its high invasion capability, metastatic properties, and the absence of effective treatments. Glycosylation serves a pivotal role in the migration and invasion of melanoma. However, differences in glycosylation between high and low metastatic melanoma cells and how these regulate migration and invasion by altering the expression of fucosyltransferases (FUTs) remain unclear. In the present study, matrix‐assisted laser desorption/ionization‐time‐of‐flight‐mass spectrometry (MALDI‐TOF‐MS) analysis revealed that the composition profiling of fucosylated N‐glycans differed between high metastatic C8161 and low metastatic A375P cells. Further analysis revealed that FUT4 expression was significantly increased in C8161 cells. Melanoma tissue arrays further demonstrated that FUT4 was overexpressed in metastatic samples. Altered FUT4 expression was accompanied by a change in the migration and invasion capacity of the cells. In addition, the migration and invasion potential of melanoma cells were decreased in C8161 and increased in A375P cells upon altering FUT4 expression levels by small interfering RNA or complementary DNA transfection. Furthermore, regulating FUT4 expression markedly modulated the activity of the phosphoinositide‐3‐kinase/Akt (PI3K/Akt) signaling pathway, which affected melanoma cell migration and invasion. In conclusion, FUT4 is a novel biomarker and regulator of the migration and invasion of melanoma cells and may serve as a therapeutic target for melanoma.
Upregulated microRNA‐194 impairs stemness of cholangiocarcinoma cells through the Rho pathway via inhibition of ECT2
Authors: Gao Jun , Dai Chao , Yu Xin , Yin Xiang‐Bao , Zhou Fan
Published: January 2020

Cholangiocarcinoma (CCA) is devastating for its delayed presence, difficulty in diagnosis, and high mortality. Other studies have supported the important role of microRNAs (miRNAs) in the pathogenesis of CCA, and the role of miR‐194 was investigated in several human cancers, though, the molecular mechanism of miR‐194 in CCA stem cells remains largely unknown. We aimed to identify the functional significance of miR‐194 in CCA. The microarray‐based analysis was applied to detect the epithelial cell transforming sequence 2 (ECT2) expression and predict the miRNA‐regulated ECT2, followed by the identification of relationship between ECT2 and obtained miRNA by dual‐luciferase reporter gene assay. The effects of depletion or ectopic expression of miR‐194 on Rho pathway and the biological characteristics of CCA were assessed by reverse transcription quantitative polymerase chain reaction, immunoblotting, 3‐(4,5‐dimethyl‐2‐thiazolyl)‐2,5‐diphenyl‐2‐H‐tetrazolium bromide, scratch test, Transwell, and flow cytometry. Lastly, tumor growth was assessed by xenograft tumor in nude mice. ECT2 was highly expressed while miR‐194 was poorly expressed in CCA stem cells, and the targeting relation between ECT2 and miR‐194 was proved. More important, the elevated expression of miR‐194 or ECT2 silencing inhibited the Rho pathway, and further promoted the apoptosis and suppressed the stem cell proliferation, migration, and invasion of CCA in vitro. miR‐194 inhibited the tumor growth in vivo. In a word, miR‐194 inhibits ECT2 and blocks the activation of Rho signaling pathway, thus promoting apoptosis, inhibiting proliferation and migration of CCA stem cells, and suppressing tumor growth. The mechanism can be regarded as a target for treating CCA.
RETRACTED: Reduction of nuclear Y654‐p‐β‐catenin expression through SH3GL2‐meditated downregulation of EGFR in chemotolerance TNBC: Clinical and prognostic importance
Authors: Islam Md. Saimul , Dasgupta Hemantika , Basu Mukta , Roy Anup , Alam Neyaz , Roychoudhury Susanta , Kumar Panda Chinmay
Published: January 2020

Triple negative breast cancer (TNBC) originates from a less differentiated ductal cell of breast, which is less sensitive to chemotherapy. The chemotolerance mechanism of TNBC has not yet been studied in detail. For this reason, molecular profiles (expression/genetic/epigenetic) of Y654‐p‐β‐catenin (active) and its kinase epidermal growth factor receptor (EGFR) along with SH3GL2 (regulator of EGFR homeostasis) were compared between neoadjuvant chemotherapy treated (NACT) and pretherapeutic TNBC samples. Reduced nuclear expression of Y654‐p‐β‐catenin protein with low proliferation index and CD44 prevalence showed concordance with reduced expression of EGFR/Y1045‐p‐EGFR proteins in the NACT samples than the pretherapeutic TNBC samples. Infrequent messenger RNA expression, gene amplification (10–32.5%), and mutation (1%) of EGFR were seen in the TNBC samples irrespective of therapy, suggesting the importance of EGFR protein stabilization in this tumor. The upregulation of SH3GL2 seen in the NACT samples in contrast to the pretherapeutic samples might be due to its promoter hypomethylation, as seen in the quantitative methylation assay. A similar trend of upregulation of SH3GL2 and downregulation of EGFR, Y1045‐p‐EGFR, Y654‐p‐β‐catenin were seen in the MDA‐MB‐231 cell line using antharacycline antitumor drugs (doxorubicin/nogalamycin). The NACT patients with reduced expression of Y654‐p‐β‐catenin and/or EGFR and high expression of SH3GL2 showed comparatively better prognosis than the pretherapeutic patients. Thus, our study showed that reduced nuclear expression of Y654‐p‐β‐catenin in NACT samples due to downregulation of EGFR protein through promoter hypomethylation‐mediated upregulation of SH3GL2, resulting in low proliferation index/CD44 prevalence with better prognosis of the NACT patients, might have an important role in the chemotolerance of TNBC.
α‐Mangostin attenuates stemness and enhances cisplatin‐induced cell death in cervical cancer stem‐like cells through induction of mitochondrial‐mediated apoptosis
Authors: Chien Hung‐Ju , Ying Tsung‐Ho , Hsieh Shu‐Ching , Lin Chia‐Liang , Yu Yung‐Luen , Kao Shao‐Hsuan , Hsieh Yi‐Hsien
Published: January 2020

Cancer stem cells (CSCs) exhibit specific characteristics including decontrolled self‐renewal, tumor‐initiating, promoting, and metastatic potential, abnormal stemness signaling, and chemotherapy resistance. Thus, targeting CSC is becoming an emerging cancer treatment. α‐Mangostin has been shown to have potent and multiple anticancer activities. Accordingly, we hypothesized that α‐mangostin may diminish the stemness and proliferation of CSC‐like cervical cancer cells. In our results, comparing to the parent cells, CSC‐like SiHa and HeLa cells highly expressed CSC marker Sox2, Oct4, Nanog, CK‐17, and CD49f. α‐Mangostin significantly reduced the cell viability, sphere‐forming ability, and expression of the CSC stemness makers of CSC‐like cervical cancer cells. Further investigation showed that α‐mangostin induced mitochondrial depolarization and mitochondrial apoptosis signaling, including upregulation of Bax, downregulation of Mcl‐1 and Bcl‐2, and activation of caspase‐9/3. Moreover, α‐mangostin synergically enhanced the cytotoxicity of cisplatin on CSC‐like SiHa cells by promoting mitochondrial apoptosis and inhibiting the expression of CSC markers. Consistent with in vitro findings, in vivo tumor growth assay revealed that α‐mangostin administration significantly inhibited the growth of inoculated CSC‐like SiHa cells and synergically enhanced the antitumor effect of cisplatin. Our findings indicate that α‐mangostin can reduce the stemness and proliferation of CSC‐like SiHa and HeLa cells and promote the cytotoxicity of cisplatin, which may attribute to the mitochondrial apoptosis activation. Thus, it suggests that α‐mangostin may have clinical potential to improve chemotherapy for cervical cancer by targeting cervical CSC.
Insights into the expression profiles and functions of circRNAs in a newborn hyperoxia‐induced rat bronchopulmonary dysplasia model
Authors: Cheng Hanrong , Wu Benqing , Wang Lingwei , Hu Tianyong , Deng Zhuhui , Li Dongcai
Published: January 2020

Background

Bronchopulmonary dysplasia (BPD) is a severe chronic lung disease in preterm infants. Circular RNAs (circRNAs) are key regulators of various biological processes. The present study aimed to explore the biological roles of circRNAs in BPD pathogenesis.

Methods

A newborn BPD rat model was developed to construct a circRNA library; Illumina deep sequencing (Illumina, San Diego, CA, USA) was used to reveal differential expression of circRNAs in the hyperoxia‐induced BPD rat models. Sanger sequencing and a reverse transcription‐polymerase chain reaction were performed to confirm circRNAs that may be related to BPD. After miRNA binding‐site prediction, we constructed a network diagram of circRNA‐competing endogenous RNAs (ceRNAs) related to transforming growth factor (TGF)‐β and p53 pathways using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis.

Results

In total, 256 differentially expressed circRNAs were detected between the hyperoxia group and the normoxia group. Of these circRNAs, 195 were up‐regulated and 61 were down‐regulated. The differences of circRNA distribution between the two groups were analyzed and six circRNAs were validated in the tissue samples. GO analysis indicated that 6519 target genes were enriched in cell location and biological processes. KEGG pathway enrichment analysis showed that circRNAs involved in 242 KEGG pathways. A network diagram of circRNA‐ceRNA related to TGF‐β and p53 pathways was constructed.

Conclusions

CircRNAs are differentially expressed between the BPD model and control group. Many target genes of circRNAs are involved in the developmental process, which suggests that BPD may be associated with pathways including extracellular matrix–receptor interaction, vascular endothelial growth factor signaling and vascular smooth muscle contraction.
Design and synthesis of diethyl(substituted 2‐benzylbenzofuran‐3‐yl)phosphonates as antioxidant and antimicrobial agents
Authors: Gundluru Mohan , Sarva Santhisudha , Sudileti Murali , Tellamekala Sreekanth , Yakkate Subba Rao , Nemallapudi Bakthavatchala Reddy , Cirandur Suresh Reddy
Published: January 2020

In continuance of our effort to improve novel and potent synthetic approaches for various bioactive phosphorylated heterocycles via C─P bond formation, a series of diethyl substituted(2‐benzylbenzofuran‐3‐yl)phosphonate derivatives (4a‐j) was synthesized by one‐pot reaction of various diversely substituted salicylaldehydes, phenyl acetylene, and diethyl phosphite using CuO nanoparticles as catalyst in 1:1 ethanol and water under room temperature. The new compounds have been studied for their radical scavenging activity by DPPH, H2O2, and NO approaches and antimicrobial activity assay against bacteria and fungi by disk diffusion method.
Structural analogues of quinoline alkaloids: Straightforward route to [1,3]dioxolo[4,5‐c]quinolines with antibacterial properties
Authors: Horák Radim , Kořistek Kamil , Šamšulová Veronika , Slaninová Ludmila , Grepl Martin , Kvapil Lubomír , Funk Petr , Hradil Pavel , Soural Miroslav
Published: January 2020

Compounds bearing [1,3]dioxolo‐quinoline scaffolds have been found in quinoline‐based natural products; the only exception is the [1,3]dioxolo[4,5‐c]quinoline moiety with a rare occurrence in both natural and synthetic derivatives. In this article, we report the preparation of diversely substituted and functionalized [1,3]dioxolo[4,5‐c]quinolines using [1,3]dioxolo[4,5‐c]quinoline‐4‐carbaldehyde (DQC) as the common intermediate. DQC was synthesized on a large scale from anthranilic acid and chloroacetone as the starting materials, with the rearrangement of acetonyl‐anthranilate as the key step. The developed method allows for the simple preparation of [1,3]dioxolo[4,5‐c]quinolines with various C2 substituents on the quinoline scaffold. Additionally, the synthetic route was successfully applied to the preparation of 3‐hydroxyquinoline‐4(1H)‐ones. The target compounds were tested against representative Gram‐positive/negative bacteria, and two derivatives exhibited submicromolar minimum inhibitory concentrations against Micrococcus luteus.
A simple protocol for the isolation of proteorhodopsins of the dinoflagellate Oxyrrhis marina
Authors: Rhiel Erhard , Nguyen Tien , Wöhlbrand Lars , Rabus Ralf
Published: January 2020

For the first time, native proteorhodopsins of the marine dinoflagellate Oxyrrhis marina were isolated. Total cell membrane fractions were minced in a bead beater and solubilized with the detergent Triton X‐100. Subsequent sucrose density gradient centrifugation resulted in three or four red‐colored bands. Nonsolubilized, but still red colored, membranes sedimented at the bottom. For each of these bands, absorbance maxima were registered at approximately 514–516 nm with shoulders toward shorter wavelengths (470–490 nm). Sodium dodecyl sulfate‐polyacrylamide gel electrophoresis revealed that the uppermost band represented free retinal chromophore, as it contained no protein. The other bands were almost pure proteorhodopsin fractions as the banding patterns showed one major protein of 25 kDa. Tryptic, in‐gel digestion of the 25 kDa proteins and of faint protein bands above and below 25 kDa was followed by mass spectrometry, confirming these protein bands to consist, nearly exclusively, proteorhodopsins. Only single peptides of few other proteins were detected. In total, at least seven predicted proteorhodopsin protein sequences were experimentally verified.