bluuebunny/crossref_metadata_2025 huggingface dataset:
Clicking Azides and Alkynes with Poly(pyrazolyl)borate-Copper(I) Catalysts: An Experimental and Computational Study
Authors: Bahsis Lahoucine , Ben El Ayouchia Hicham , Anane Hafid , Ramirez de Arellano Carmen , Bentama Abdeslem , El Hadrami El , Julve Miguel , Domingo Luis , Stiriba Salah-Eddine
Published: August 2019

The synthesis of 1,4-disubstituted-1,2,3-triazoles under a copper(I)-catalyzed azide–alkyne cycloaddition (CuAAC) regime was accomplished in high yields and a regioselective manner by using two homoscorpionate poly(pyrazolyl)borate anions: tris(pyrazolyl)hydroborate (HB(pz)3−) and bis(pyrazolyl)hydroborate (H2B(pz)2−), which stabilized in situ the catalytically active copper (I) center. The [3+2] cycloaddition (32CA) reactions took place under strict click conditions, including room temperature and a mixture of environmentally benign solvents such as water/ethanol in a 1:1 (v/v) ratio. These click chemistry conditions were applied to form complex 1,2,3-triazoles-containing sugar moieties, which are potentially relevant from a biological point of view. Computational modeling carried out by DFT methodologies at the B3LYP/6-31G(d) level showed that the coordination of poly(pyrazolyl)borate-copper(I) to alkyne groups produced relevant changes in terms of generating a high polar copper(I)-acetylide intermediates. The analysis of the global and local reactivity indices explains correctly the role of poly(pyrazolyl)borate ligands in the stabilization and activation of the copper(I) catalyst in the studied 32CA reactions.
Ni/CeO2 Structured Catalysts for Solar Reforming of Spent Solvents
Authors: Landi Gianluca , Di Benedetto Almerinda
Published: August 2019

Spent solvents of the packaging industry are disposed of, thus representing economic, safety, and environmental issues. Steam reforming of these solvent streams can be an alternative, allowing their valorization to syngas. In this work, ceria supported nickel catalysts were deposed onto silicon carbide (SiC) honeycomb monoliths; these structured catalysts can be potentially used in solar steam reforming. Catalysts were characterized by SEM/EDS and tested in a lab-scale rig under conventional heating. Two spent solvent streams, coming from the distillation plant of the packaging industry Icimendue, were used as fuels. Catalytic tests have been carried out by changing the steam/carbon ratio, oxygen/carbon ratio, operating pressure, and fuel. The effect of the Ni content and the type of ceria were also studied. The best performances were obtained at low Ni content and by using micrometric rather than nanometric ceria as support. The structured catalysts showed good coking resistance, especially at H2O/C > 2, with oxygen addition furnishing a marginal improvement. On the contrary, oxygen feeding reduced the gas yield due to the formation of by-products being less reactive in reforming reactions. Performing the reforming process at high pressure the gas yield increased due to faster kinetics (higher reactants concentrations), higher contact times (slower flow rates), and process intensification. These results suggest that the proposed structured catalysts could be successfully applied in the solar reforming of spent solvents.
The Effects of Catalyst Support and Temperature on the Hydrotreating of Waste Cooking Oil (WCO) over CoMo Sulfided Catalysts
Authors: Wang Hui , Rogers Kyle , Zhang Haiping , Li Guoliang , Pu Jianglong , Zheng Haoxuan , Lin Hongfei , Zheng Ying , Ng Siauw
Published: August 2019

Waste cooking oil (WCO) hydrotreating to produce green diesel is good for both the environmental protection and energy recovery problems. The roles of catalyst support and reaction temperature on reactions during WCO hydrotreating process were evaluated over an unsupported and a commercial sulfided cobalt and molybdenum (CoMoS) catalyst supported by a mixture of Al2O3, TiO2, and SiO2. The presence of catalyst support helped to improve the dispersion and enlarge the surface area of CoMoS, and was found to be a key factor in reducing reaction temperature, in enhancing the hydrodeoxygenation (HDO) and hydrogenation capabilities, and in decreasing polymerization capability. The increase of reaction temperature strongly improved the deoxygenation, hydrogenation, and cracking reaction activities. Compared to the unsupported CoMoS, the supported one exhibited good deoxygenation and hydrogenation capabilities at 340 °C in WCO hydrotreating to produce diesel fraction; however, high temperature operation needs to be carefully controlled because it may cause overcracking and dehydrogenation.
Cerium- and Iron-Oxide-Based Nanozymes in Tissue Engineering and Regenerative Medicine
Authors: Jansman Michelle M. T. , Hosta-Rigau Leticia
Published: August 2019

Nanoparticulate materials displaying enzyme-like properties, so-called nanozymes, are explored as substitutes for natural enzymes in several industrial, energy-related, and biomedical applications. Outstanding high stability, enhanced catalytic activities, low cost, and availability at industrial scale are some of the fascinating features of nanozymes. Furthermore, nanozymes can also be equipped with the unique attributes of nanomaterials such as magnetic or optical properties. Due to the impressive development of nanozymes during the last decade, their potential in the context of tissue engineering and regenerative medicine also started to be explored. To highlight the progress, in this review, we discuss the two most representative nanozymes, namely, cerium- and iron-oxide nanomaterials, since they are the most widely studied. Special focus is placed on their applications ranging from cardioprotection to therapeutic angiogenesis, bone tissue engineering, and wound healing. Finally, current challenges and future directions are discussed.
Core-Shell Fe3O4@NCS-Mn Derived from Chitosan-Schiff Based Mn Complex with Enhanced Catalytic Activity for Oxygen Reduction Reaction
Authors: Tong Jinhui , Li Yuliang , Bo Lili , Wang Wenhui , Li Tao , Zhang Qi
Published: August 2019

A core-shell type of Fe3O4/NCS-Mn composite was prepared by pyrolyzing a precursor fabricated by coating a chitosan-Schiff base Mn complex on Fe3O4 cores. For comparison purposes, the Fe3O4@NCS sample in the absence of Mn and the Fe3O4@NC sample derived from just chitosan coating Fe3O4 were also prepared. Among the three catalysts, Fe3O4@NCS-Mn demonstrates the best electrocatalytic activity compared to commercial Pt/C (20%) for oxygen reduction reaction (ORR). The average of the transferred electron number (n) approached 3.6 in the range of −0.3 to −0.8 V (vs. Ag/AgCl). Moreover, the catalyst exhibited high stability and durability against methanol and may potentially be a promising ORR catalyst for fuel cells.
Fast Method for Testing the Photocatalytic Performance of Modified Gypsum
Authors: Janus Magdalena , Zając Kamila , Ehm Clemens , Stephan Dietmar
Published: August 2019

The measurement of the photocatalytic activity of building materials is quite time-consuming. Up until now, researchers have mainly used the equipment described in ISO 22197-1 to ISO 22197-4 for the determination of air purification activity, although other apparatus such as colorimeters, UV-Vis/DR spectroscopes and equipment for contact angle measurements have also been used. Usually, photocatalytic activity measurements take from one hour up to several hours. In this study, we present a very fast method for the measurement of the photocatalytic activity of gypsum. A specially designed printer with a modified bubblejet cartridge was used to apply a special ink on the surface of gypsum plates. Then the surface was irradiated by UV-A light and every 3 s a picture of the surface was taken. The results showed that the discoloration of the dye occurs after a few seconds of irradiation and the time depends on the amount of photocatalyst used as well as the number of printed ink layers. It was concluded that it is possible to use this method for a quick comparison of the photocatalytic activity of different types of modified gypsum materials.
Loss of Peter Pan (PPAN) Affects Mitochondrial Homeostasis and Autophagic Flux
Authors: Dannheisig David P. , Beck Eileen , Calzia Enrico , Walther Paul , Behrends Christian , Pfister Astrid S.
Published: August 2019

Nucleolar stress is a cellular response to inhibition of ribosome biogenesis or nucleolar disruption leading to cell cycle arrest and/or apoptosis. Emerging evidence points to a tight connection between nucleolar stress and autophagy as a mechanism underlying various diseases such as neurodegeneration and treatment of cancer. Peter Pan (PPAN) functions as a key regulator of ribosome biogenesis. We previously showed that human PPAN localizes to nucleoli and mitochondria and that PPAN knockdown triggers a p53-independent nucleolar stress response culminating in mitochondrial apoptosis. Here, we demonstrate a novel role of PPAN in the regulation of mitochondrial homeostasis and autophagy. Our present study characterizes PPAN as a factor required for maintaining mitochondrial integrity and respiration-coupled ATP production. PPAN interacts with cardiolipin, a lipid of the inner mitochondrial membrane. Down-regulation of PPAN enhances autophagic flux in cancer cells. PPAN knockdown promotes recruitment of the E3-ubiquitin ligase Parkin to damaged mitochondria. Moreover, we provide evidence that PPAN knockdown decreases mitochondrial mass in Parkin-expressing cells. In summary, our study uncovers that PPAN knockdown is linked to mitochondrial damage and stimulates autophagy.
Therapeutic Targeting of the IGF Axis
Authors: Osher Eliot , Macaulay Valentine M.
Published: August 2019

The insulin like growth factor (IGF) axis plays a fundamental role in normal growth and development, and when deregulated makes an important contribution to disease. Here, we review the functions mediated by ligand-induced IGF axis activation, and discuss the evidence for the involvement of IGF signaling in the pathogenesis of cancer, endocrine disorders including acromegaly, diabetes and thyroid eye disease, skin diseases such as acne and psoriasis, and the frailty that accompanies aging. We discuss the use of IGF axis inhibitors, focusing on the different approaches that have been taken to develop effective and tolerable ways to block this important signaling pathway. We outline the advantages and disadvantages of each approach, and discuss progress in evaluating these agents, including factors that contributed to the failure of many of these novel therapeutics in early phase cancer trials. Finally, we summarize grounds for cautious optimism for ongoing and future studies of IGF blockade in cancer and non-malignant disorders including thyroid eye disease and aging.
Gap Junction Intercellular Communication in the Carcinogenesis Hallmarks: Is This a Phenomenon or Epiphenomenon?
Authors: Zefferino Roberto , Piccoli Claudia , Di Gioia Sante , Capitanio Nazzareno , Conese Massimo
Published: August 2019

If occupational tumors are excluded, cancer causes are largely unknown. Therefore, it appeared useful to work out a theory explaining the complexity of this disease. More than fifty years ago the first demonstration that cells communicate with each other by exchanging ions or small molecules through the participation of connexins (Cxs) forming Gap Junctions (GJs) occurred. Then the involvement of GJ Intercellular Communication (GJIC) in numerous physiological cellular functions, especially in proliferation control, was proven and accounts for the growing attention elicited in the field of carcinogenesis. The aim of the present paper is to verify and discuss the role of Cxs, GJs, and GJIC in cancer hallmarks, pointing on the different involved mechanisms in the context of the multi-step theory of carcinogenesis. Functional GJIC acts both as a tumor suppressor and as a tumor enhancer in the metastatic stage. On the contrary, lost or non-functional GJs allow the uncontrolled proliferation of stem/progenitor initiated cells. Thus, GJIC plays a key role in many biological phenomena or epiphenomena related to cancer. Depending on this complexity, GJIC can be considered a tumor suppressor in controlling cell proliferation or a cancer ally, with possible preventive or therapeutic implications in both cases.
Parkin-Dependent Mitophagy Is Required for the Inhibition of ATF4 on NLRP3 Inflammasome Activation in Cerebral Ischemia-Reperfusion Injury in Rats
Authors: He Qi , Li Zhenyu , Meng Changchang , Wu Jingxian , Zhao Yong , Zhao Jing
Published: August 2019

Background: Nod-like receptor protein 3 (NLRP3) inflammasome is a crucial contributor in the inflammatory process during cerebral ischemia/reperfusion (I/R) injury. ATF4 plays a pivotal role in the pathogenesis of cerebral I/R injury, however, its function and underlying mechanism are not fully characterized yet. In the current study, we examined whether ATF4 ameliorates cerebral I/R injury by inhibiting NLRP3 inflammasome activation and whether mitophagy is involved in this process. In addition, we explored the role of parkin in ATF4-mediated protective effects. Method: To address these issues, healthy male adult Sprague-Dawley rats were exposed to middle cerebral artery occlusion for 1 h followed by 24 h reperfusion. Adeno-associated virus (AAV) and siRNA were injected into rats to overexpress and knockdown ATF4 expression, respectively. After pretreatment with AAV, mdivi-1(mitochondrial division inhibitor-1) was injected into rats to block mitophagy activity. Parkin expression was knockdown using specific siRNA after AAV pretreatment. Result: Data showed that ATF4 overexpression induced by AAV was protective against cerebral I/R injury, as evidenced by reduced cerebral infraction volume, decreased neurological scores and improved outcomes of HE and Nissl staining. In addition, overexpression of ATF4 gene was able to up-regulate Parkin expression, enhance mitophagy activity and inhibit NLRP3 inflammasome-mediated inflammatory response. ATF4 knockdown induced by siRNA resulted in the opposite effects. Furthermore, ATF4-mediated inhibition of NLRP3 inflammasome activation was strongly affected by mitophagy blockage upon mdivi-1 injection. Besides, ATF4-mediated increase of mitophagy activity and inhibition of NLRP3 inflammasome activation were effectively reversed by Parkin knockdown using siRNA. Conclusion: Our study demonstrated that ATF4 is able to alleviate cerebral I/R injury by suppressing NLRP3 inflammasome activation through parkin-dependent mitophagy activity. These results may provide a new strategy to relieve cerebral I/R injury by modulating mitophagy-NLRP3 inflammasome axis.
Low Stability of Integrin-Binding Deficient Mutant of FGF1 Restricts Its Biological Activity
Authors: Szlachcic Anna , Sochacka Martyna , Czyrek Aleksandra , Opalinski Lukasz , Krowarsch Daniel , Otlewski Jacek , Zakrzewska Malgorzata
Published: August 2019

Fibroblast growth factor 1 (FGF1) has been shown to interact with integrin αvβ3 through a specific binding site, involving Arg35 residue. The FGF1 mutant (R35E) with impaired integrin binding was found to be defective in its proliferative response, although it was still able to interact with FGF receptors (FGFR) and heparin and induce the activation of downstream signaling pathways. Here, we demonstrate that the lack of mitogenic potential of R35E mutant is directly caused by its decreased thermodynamic stability and susceptibility to proteolytic degradation. Introduction of three stabilizing mutations into R35E variant compensated the effect of destabilizing R35E mutation and restored the proliferation potential of FGF1. Moreover, the stabilized R35E variant regained both anti-apoptotic and wound healing activities, while remaining defective in binding to integrin αvβ3. Our results suggest that the thermodynamic stability and resistance to degradation, rather than the interaction with integrin are required for mitogenic response of FGF1.
Zebrafish in Inflammasome Research
Authors: Forn-Cuní Gabriel , Meijer Annemarie H. , Varela Monica
Published: August 2019

Inflammasomes are cytosolic multiprotein complexes that regulate inflammatory responses to danger stimuli and infection, and their dysregulation is associated with an increasing number of autoinflammatory diseases. In recent years, zebrafish models of human pathologies to study inflammasome function in vivo have started to emerge. Here, we discuss inflammasome research in zebrafish in light of current knowledge about mammalian inflammasomes. We summarize the evolutionary conservation of inflammasome components between zebrafish and mammals, highlighting the similarities and possible divergence in functions of these components. We present new insights into the evolution of the caspase-1 family in the teleost lineage, and how its evolutionary origin may help contextualize its functions. We also review existing infectious and non-infectious models in zebrafish in which inflammasomes have been directly implicated. Finally, we discuss the advantages of zebrafish larvae for intravital imaging of inflammasome activation and summarize available tools that will help to advance inflammasome research.
Genome-Wide Identification and Characterization of Long Noncoding RNAs of Brown to White Adipose Tissue Transformation in Goats
Authors: Wang Linjie , Yang Xin , Zhu Yuehua , Zhan Siyuan , Chao Zhe , Zhong Tao , Guo Jiazhong , Wang Yan , Li Li , Zhang Hongping
Published: August 2019

Long noncoding RNAs (lncRNAs) play an important role in the thermogenesis and energy storage of brown adipose tissue (BAT). However, knowledge of the cellular transition from BAT to white adipose tissue (WAT) and the potential role of lncRNAs in goat adipose tissue remains largely unknown. In this study, we analyzed the transformation from BAT to WAT using histological and uncoupling protein 1 (UCP1) gene analyses. Brown adipose tissue mainly existed within the goat perirenal fat at 1 day and there was obviously a transition from BAT to WAT from 1 day to 1 year. The RNA libraries constructed from the perirenal adipose tissues of 1 day, 30 days, and 1 year goats were sequenced. A total number of 21,232 lncRNAs from perirenal fat were identified, including 5393 intronic-lncRNAs and 3546 antisense-lncRNAs. Furthermore, a total of 548 differentially expressed lncRNAs were detected across three stages (fold change ≥ 2.0, false discovery rate (FDR) < 0.05), and six lncRNAs were validated by qPCR. Furthermore, trans analysis found lncRNAs that were transcribed close to 890 protein-coding genes. Additionally, a coexpression network suggested that 4519 lncRNAs and 5212 mRNAs were potentially in trans-regulatory relationships (r > 0.95 or r < −0.95). In addition, Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses showed that the targeted genes were involved in the biosynthesis of unsaturated fatty acids, fatty acid elongation and metabolism, the citrate cycle, oxidative phosphorylation, the mitochondrial respiratory chain complex, and AMP-activated protein kinase (AMPK) signaling pathways. The present study provides a comprehensive catalog of lncRNAs involved in the transformation from BAT to WAT and provides insight into understanding the role of lncRNAs in goat brown adipogenesis.
Solvatochromism and Selective Sorption of Volatile Organic Solvents in Pyridylbenzoate Metal-Organic Frameworks
Authors: Ndamyabera Christophe A. , Zacharias Savannah C. , Oliver Clive L. , Bourne Susan A.
Published: August 2019

Using cobalt(II) as a metal centre with different solvent systems afforded the crystallization of isomorphous metal-organic frameworks {[Co(34pba)(44pba)]·DMF}n (1) and {[Co(34pba)(44pba)]·(C3H6O)}n (2) from mixed 4-(4-pyridyl)benzoate (44pba) and 3-(4-pyridyl)benzoate (34pba) ligands. Zinc(II) under the same reaction conditions that led to the formation of 1 formed an isostructural {[Zn(34pba)(44pba)]·DMF}n framework (3). Crystal structures of all three MOFs were elucidated and their thermal stabilities were determined. The frameworks of 1, 2, and 3 were activated under vacuum to form the desolvated forms 1d, 2d, and 3d, respectively. PXRD results showed that 1d and 2d were identical, consequently, 1d and 3d were then investigated for sorption of volatile organic compounds (VOCs) containing either chloro or amine moieties. Thermogravimetric analysis (TGA) and nuclear magnetic resonance (NMR) were used to determine the sorption capacity and selectivity for the VOCs. Some sorption products of 1d with amines became amorphous, but the crystalline framework could be recovered on desorption of the amines. Investigation of the sorption of water (H2O) and ammonia (NH3) in 1d gave rise to new phases identifiable by means of a colour change (solvatochromism). The kinetics of desorption of DMF, water and ammonia from frameworks 1d and 3d were studied using non-isothermal TGA. Activation energies for both cobalt(II) and zinc(II) frameworks are in the order NH3 < H2O < DMF, with values for the 1d analogue always higher than those for 3d.
A Naphthalimide-Benzothiazole Conjugate as Colorimetric and Fluorescent Sensor for Selective Trinitrophenol Detection
Authors: D. Jawale Patil Pramod , D. Ingle Rajita , M. Wagalgave Sopan , S. Bhosale Rajesh , V. Bhosale Sidhanath , P. Pawar Rajendra , V. Bhosale Sheshanath
Published: August 2019

Although chemical structural modification of naphthalimides is widely employed for the purpose of sensing explosives, the effects of such modification have been little explored. Herein, we report the design and synthesis of a new naphthalimide-benzothiazole conjugate (1) and its ability to sense various nitrophenols by means of its colorimetric and fluorescent characteristics. Under long-range UV light (365 nm), 1 displayed a color change of its solution from bluish to colorless only upon addition of 2,4,6-trinitrophenol (TNP). Photoluminescence spectroscopy showed quantitative fluorescence quenching by TNP of the emission peaks of 1 at 398 nm and 418 nm due to donor–acceptor electron transfer. The interaction of 1 with TNP was via a cooperative, non-covalent hydrogen-bonding interaction. Receptor 1 exhibited high sensitivity and selectivity towards TNP over various aromatic nitro analytes. The binding constant (K) and Stern–Volmer constant (Ksv) between 1 and TNP were found to be 5.332 × 10−5 M and 2.271 × 106 M−1, respectively. Furthermore, the limit of detection was calculated and found to be as low as 1.613 × 10−10 M.
Land-Use/Land-Cover Changes and Their Impact on Surface Urban Heat Islands: Case Study of Kandy City, Sri Lanka
Authors: Dissanayake DMSLB , Morimoto Takehiro , Ranagalage Manjula , Murayama Yuji
Published: August 2019

An urban heat island (UHI) is a phenomenon that shows a higher temperature in urban areas compared to surrounding rural areas due to the impact of impervious surface (IS) density, and other anthropogenic activities including changes of land use/land cover (LULC). The purpose of this research is to examine the spatiotemporal land-use/land-cover changes and their impact on the surface UHI (SUHI) in Kandy City, Sri Lanka, using Landsat data and geospatial techniques. LULC classification was made by using a pixel-oriented supervised classification method, and LULC changes were computed by using a cross-cover comparison. The SUHI effect was discussed mainly through the variation of land-surface temperature (LST) over persistent IS and newly added IS. The study showed the dynamics of each LULC and its role in the SUHI. The results showed that IS areas expanded from 529 to 1514 ha (2.3% to 6.7% of the total land area) between 1996 and 2006, and to 5833 ha (23.9% of the total land area) in 2017, with an annual growth rate of 11.1% per year from 1996 to 2006 and 12.2% per year from 2006 to 2017. A gradually declining trend was observed in forest areas. Persistent IS reported the highest mean LST areas compared to newly added IS. The mean LST difference between persistent IS and newly added IS was 1.43 °C over the study period. This is because areas of persistent IS are typically surrounded by IS even in their neighborhoods, whereas areas of newly added IS occur at the edges of the city and are, therefore, cooled by the surrounding nonurban surfaces. This calls for appropriate green-oriented landscape-management methods to mitigate the impact of the SUHI in Kandy City. The findings of the study showed that LULC changes and their effect on the SUHI from 1996 to 2017 made a significant contribution to long records of change dynamics.
Fused Deposition Modelling as a Potential Tool for Antimicrobial Dialysis Catheters Manufacturing: New Trends vs. Conventional Approaches
Authors: Mathew Essyrose , Domínguez-Robles Juan , Larrañeta Eneko , Lamprou Dimitrios A.
Published: August 2019

The rising rate of individuals with chronic kidney disease (CKD) and ineffective treatment methods for catheter-associated infections in dialysis patients has led to the need for a novel approach to the manufacturing of catheters. The current process requires moulding, which is time consuming, and coated catheters used currently increase the risk of bacterial resistance, toxicity, and added expense. Three-dimensional (3D) printing has gained a lot of attention in recent years and offers the opportunity to rapidly manufacture catheters, matched to patients through imaging and at a lower cost. Fused deposition modelling (FDM) in particular allows thermoplastic polymers to be printed into the desired devices from a model made using computer aided design (CAD). Limitations to FDM include the small range of thermoplastic polymers that are compatible with this form of printing and the high degradation temperature required for drugs to be extruded with the polymer. Hot-melt extrusion (HME) allows the potential for antimicrobial drugs to be added to the polymer to create catheters with antimicrobial activity, therefore being able to overcome the issue of increased rates of infection. This review will cover the area of dialysis and catheter-related infections, current manufacturing processes of catheters and methods to prevent infection, limitations of current processes of catheter manufacture, future directions into the manufacture of catheters, and how drugs can be incorporated into the polymers to help prevent infection.
The Formation of Microcrystal in Helium Ion Irradiated Aluminum Alloy
Authors: Wan Hao , Zhao Shuai , Jin Qi , Yang Tingyi , Si Naichao
Published: August 2019

A microstructure variation in Al-1060 alloy after helium ion irradiation was revealed by a transmission electron microscope (TEM). The result shows that ion irradiation produced dislocations, dislocation loops, cavities and microcrystals in the irradiated layer. Dislocation-defect interactions were portrayed, especially the pinning effect of a dislocation loop and cavity on moving dislocation. Irradiation-induced stress was recognized as the main factor which impacted on the interaction of defect. Based on the dislocation inhibited with irradiation defects, the mechanism of microcrystal formation was proposed.
Relationship between Oxygen Defects and Properties of Scandium Oxide Films Prepared by Ion-Beam Sputtering
Authors: Kong Pengfei , Pu Yunti , Ma Ping , Zhu Jiliang
Published: August 2019

Scandium oxide (Sc2O3) thin films with different numbers of oxygen defects were prepared by ion-beam sputtering under different oxygen flow rates. The results showed that the oxygen defects heavily affected crystal phases, optical properties, laser-induced damage threshold (LIDT) and surface quality of Sc2O3 films. The thin film under 0 standard-state cubic centimeter per minute (sccm) oxygen flow rate had the largest number of oxygen defects, which resulted in the lowest transmittance, LIDT and the worst surface quality. In addition, the refractive index of 0 sccm Sc2O3 film could not be measured in the same way. When the oxygen flow rate was 15 sccm, the Sc2O3 film possessed the best transmittance, refractive index, LIDT and surface roughness due to the lowest number of oxygen defects. This work elucidated the relationship between oxygen defects and properties of Sc2O3 films. Controlling oxygen flow rate was an important step of limiting the number of oxygen defects, which is of great significance for industrial production.
Characterization of Biofilm Formation and Coating Degradation by Electrochemical Impedance Spectroscopy
Authors: Permeh Samanbar , Lau Kingsley , Duncan Matthew
Published: August 2019

Recent findings showed severe localized corrosion of submerged steel bridge piles in a Florida bridge and was associated with microbial activity in the presence of marine foulers. Microbiologically influenced corrosion (MIC) can cause severe degradation of submerged steel infrastructure with the presence of biofilm associated with microorganisms such as sulfate reducing bacteria (SRB). Coatings have been developed to mitigate MIC and marine fouling. Coating degradation and disbondment can occur as a result of microbial attack due to the production of metabolites that degrade coating chemical and physical properties. In the work described here, electrochemical impedance spectroscopy (EIS) was conducted to identify microbial activity and degradation of an antifouling coating exposed to SRB-inoculated modified Postgate B solution. The measurements resulted in complicated impedance with multiple loops in the Nyquist diagram associated with the coating material, development of surface layers (biofilm), and the steel interface. Deconvolution of the impedance results and fitting to equivalent circuit analogs were made to identify coating characteristics and surface layer formation. EIS test results revealed coating degradation and subsequent formation of surface layers associated with SRB due to coating self-polishing and depletion of biocide components.
Tribomechanical Behaviour of TiAlN and CrAlN Coatings Deposited onto AISI H11 with Different Pre-Treatments
Authors: Tillmann Wolfgang , Grisales Diego , Stangier Dominic , Butzke Timo
Published: August 2019

In the metalworking industry, different processes and applications require the utilisation of custom designed tools. The selection of the appropriated substrate material and its pre-treatment as well as the protective coating are of great importance in the performance and life time of forming tools, dies, punches and coated parts in general. TiAlN and CrAlN coatings have been deposited onto the hot work tool steel AISI H11 by means of Direct Current Magnetron Sputtering. Prior to the deposition, the steel substrate was modified by the implementation of three different pre-treatments: nitriding of the annealed substrate [Nitr.], heat treatment of the steel (quenching and double tempering) [HT] and nitridation subsequent to a heat treatment of the substrate [HT + Nitr.]. The purpose of this research is to obtain valuable information on the microstructural properties and tribomechanical behaviour of two of the most promising ternary transition metal nitride coatings, TiAlN and CrAlN, when deposited on the AISI H11 steel with different initial properties. The different pre-treatments performed to the steel prior to the deposition favour the tailoring during the design and construction of tools for specific applications. The microstructure, the adhesion and the wear resistance of TiAlN coatings were highly influenced by the substrate preparation. Contrarily, CrAlN results were more independent of the substrate preparation and no high influences were found. For instance, the adhesion of the TiAlN coating varied from 17 to 43 N for the coating deposited onto the HT + Nitr. substrate and the HT substrate respectively, while the lowest and highest adhesion of the CrAlN coating varied between 42 and 53 N for the HT and the HT + Nitr. respectively. Likewise, the wear coefficient of the CrAlN were ten times smaller than those found for the TiAlN coatings, presumably due to the presence of hex-AlN phases and the small differences on the Young´s Modulus of the substrate and the CrAlN coatings.
Review of CdTe1−xSex Thin Films in Solar Cell Applications
Authors: Lingg Martina , Buecheler Stephan , Tiwari Ayodhya N.
Published: August 2019

Recent improvements in CdTe thin film solar cells have been achieved by using CdTe1−xSex as a part of the absorber layer. This review summarizes the published literature concerning the material properties of CdTe1−xSex and its application in current thin film CdTe photovoltaics. One of the important properties of CdTe1−xSex is its band gap bowing, which facilitates a lowering of the CdTe band gap towards the optimum band gap for highest theoretical efficiency. In practice, a CdTe1−xSex gradient is introduced to the front of CdTe, which induces a band gap gradient and allows for the fabrication of solar cells with enhanced short-circuit current while maintaining a high open-circuit voltage. In some device structures, the addition of CdTe1−xSex also allows for a reduction in CdS thickness or its complete elimination, reducing parasitic absorption of low wavelength photons.
Multilingual Ranking of Wikipedia Articles with Quality and Popularity Assessment in Different Topics
Authors: Lewoniewski Włodzimierz , Węcel Krzysztof , Abramowicz Witold
Published: August 2019

On Wikipedia, articles about various topics can be created and edited independently in each language version. Therefore, the quality of information about the same topic depends on the language. Any interested user can improve an article and that improvement may depend on the popularity of the article. The goal of this study is to show what topics are best represented in different language versions of Wikipedia using results of quality assessment for over 39 million articles in 55 languages. In this paper, we also analyze how popular selected topics are among readers and authors in various languages. We used two approaches to assign articles to various topics. First, we selected 27 main multilingual categories and analyzed all their connections with sub-categories based on information extracted from over 10 million categories in 55 language versions. To classify the articles to one of the 27 main categories, we took into account over 400 million links from articles to over 10 million categories and over 26 million links between categories. In the second approach, we used data from DBpedia and Wikidata. We also showed how the results of the study can be used to build local and global rankings of the Wikipedia content.
Quest for Compounds at the Verge of Charge Transfer Instabilities: The Case of Silver(II) Chloride †
Authors: Derzsi Mariana , Grzelak Adam , Kondratiuk Paweł , Tokár Kamil , Grochala Wojciech
Published: August 2019

Electron-transfer processes constitute one important limiting factor governing stability of solids. One classical case is that of CuI2, which has never been prepared at ambient pressure conditions due to feasibility of charge transfer between metal and nonmetal (CuI2 → CuI + ½ I2). Sometimes, redox instabilities involve two metal centers, e.g., AgO is not an oxide of divalent silver but rather silver(I) dioxoargentate(III), Ag(I)[Ag(III)O2]. Here, we look at the particularly interesting case of a hypothetical AgCl2 where both types of redox instabilities operate simultaneously. Since standard redox potential of the Ag(II)/Ag(I) redox pair reaches some 2 V versus Normal Hydrogen Electrode (NHE), it might be expected that Ag(II) would oxidize Cl− anion with great ease (standard redox potential of the ½ Cl2/Cl− pair is + 1.36 V versus Normal Hydrogen Electrode). However, ionic Ag(II)Cl2 benefits from long-distance electrostatic stabilization to a much larger degree than Ag(I)Cl + ½ Cl2, which affects relative stability. Moreover, Ag(II) may disproportionate in its chloride, just like it does in an oxide; this is what AuCl2 does, its formula corresponding in fact to Au(I)[Au(III)Cl4]. Formation of polychloride substructure, as for organic derivatives of Cl3− anion, is yet another possibility. All that creates a very complicated potential energy surface with a few chemically distinct minima i.e., diverse polymorphic forms present. Here, results of our theoretical study for AgCl2 will be presented including outcome of evolutionary algorithm structure prediction method, and the chemical identity of the most stable form will be uncovered together with its presumed magnetic properties. Contrary to previous rough estimates suggesting substantial instability of AgCl2, we find that AgCl2 is only slightly metastable (by 52 meV per formula unit) with respect to the known AgCl and ½ Cl2, stable with respect to elements, and simultaneously dynamically (i.e., phonon) stable. Thus, our results point out to conceivable existence of AgCl2 which should be targeted via non-equilibrium approaches.
Invasive Goldenrod (Solidago gigantea) Influences Soil Microbial Activities in Forest and Grassland Ecosystems in Central Europe
Authors: Bobuľská Lenka , Demková Lenka , Čerevková Andrea , Renčo Marek
Published: August 2019

A giant goldenrod plant, Solidago gigantea, native to North America is rapidly spreading in Europe and may have serious impact on ecosystems that inhabit. There is a lack of information about the effects of this species on soil biochemical properties and distribution and activity of microbial community. We analyzed soil physicochemical properties (soil reaction, soil moisture content, organic carbon and total nitrogen content) associated with activity of microbial population (activity of fluorescein diacetate (FDA), beta-glucosidase, urease and phosphatases enzymes) between invaded and adjacent uninvaded control sites in two habitats, forest and grassland, in the lowland of southeast Slovakia during years 2016 and 2017. The results revealed that invasion of S. gigantea significantly altered several soil properties and is associated with different soil properties. Soil acidity increased, organic carbon and moisture content decreased, while total nitrogen content was not significantly affected by invasion. FDA and urease activity were significantly higher in uninvaded sites. In contrast, beta-glucosidase and alkaline phosphatase activity were enhanced by S. gigantea invasion in both ecosystems studied. Acid phosphatase was not affected by the invasion. Our study proved that S. gigantea can influence several soil microbial properties while others remained unaffected, despite its significant impact on basal soil physicochemical properties.
Genetic Diversity and Population Structure of Bermudagrass [Cynodon dactylon (L.) Pers.] along Latitudinal Gradients and the Relationship with Polyploidy Level
Authors: Zhang Jingxue , Wang Miaoli , Guo Zhipeng , Guan Yongzhuo , Liu Jianyu , Yan Xuebing , Guo Yuxia
Published: August 2019

Understanding the population genetic pattern and process of gene flow requires a detailed knowledge of how landscape characteristics structure populations. Although Cynodon dactylon (L.) Pers. (common bermudagrass) is widely distributed in the world, information on its genetic pattern and population structure along latitudinal gradients is limited. We tried to estimate the genetic diversity and genetic structure of C. dactylon along a latitudinal gradient across China. Genetic diversity among different ploidy levels was also compared in the study. The material used consisted of 296 C. dactylon individuals sampled from 16 geographic sites from 22°35′ N to 36°18′ N. Genetic diversity was estimated using 153 expressed sequence tag-derived simple sequence repeat (EST-SSR) loci. Higher within-population genetic diversity appeared at low-latitude, as well as having positive correlation with temperature and precipitation. The genetic diversity increased with the ploidy level of C. dactylon, suggesting polyploidy creates higher genetic diversity. No isolation by distance and notable admixture structure existed among populations along latitudes. Both seed dispersal (or vegetative organs) and extrinsic pollen played important roles for gene flow in shaping the spatial admixture population structure of C. dactylon along latitudes. In addition, populations were separated into three clusters according to ploidy levels. C. dactylon has many such biological characters of perennial growth, wind-pollination, polyploidy, low genetic differentiation among populations, sexual and asexual reproduction leading to higher genetic diversity, which gives it strong adaptability with its genetic patterns being very complex across all the sampled latitudes. The findings of this study are related to landscape population evolution, polyploidy speciation, preservation, and use of bermudagrass breeding.
Who Is Classified as Untestable on Brief Cognitive Screens in an Acute Stroke Setting?
Authors: Elliott Emma , Drozdowska Bogna A. , Taylor-Rowan Martin , Shaw Robert C. , Cuthbertson Gillian , Quinn Terence J.
Published: August 2019

Full completion of cognitive screening tests can be problematic in the context of a stroke. Our aim was to examine the completion of various brief cognitive screens and explore reasons for untestability. Data were collected from consecutive stroke admissions (May 2016–August 2018). The cognitive assessment was attempted during the first week of admission. Patients were classified as partially untestable (≥1 test item was incomplete) and fully untestable (where assessment was not attempted, and/or no questions answered). We assessed univariate and multivariate associations of test completion with: age (years), sex, stroke severity (National Institutes of Health Stroke Scale (NIHSS)), stroke classification, pre-morbid disability (modified Rankin Scale (mRS)), previous stroke and previous dementia diagnosis. Of 703 patients admitted (mean age: 69.4), 119 (17%) were classified as fully untestable and 58 (8%) were partially untestable. The 4A-test had 100% completion and the clock-draw task had the lowest completion (533/703, 76%). Independent associations with fully untestable status had a higher NIHSS score (odds ratio (OR): 1.18, 95% CI: 1.11–1.26), higher pre-morbid mRS (OR: 1.28, 95% CI: 1.02–1.60) and pre-stroke dementia (OR: 3.35, 95% CI: 1.53–7.32). Overall, a quarter of patients were classified as untestable on the cognitive assessment, with test incompletion related to stroke and non-stroke factors. Clinicians and researchers would benefit from guidance on how to make the best use of incomplete test data.
Development of a Highly Sensitive Technique for Capturing Renal Cell Cancer Circulating Tumor Cells
Authors: Naoe Michio , Kusaka Chiho , Ohta Mika , Hasebe Yuki , Unoki Tsutomu , Shimoyama Hideaki , Nakasato Takehiko , Oshinomi Kazuhiko , Morita Jun , Fuji Kohzo , Ogawa Yoshio , Tsukada Mana , Sunagawa Masataka , Ishii Hikaru
Published: August 2019

purpose: Liquid biopsy is becoming increasingly important as a guide for selecting new drugs and determining their efficacy. In urological cancer, serum markers for renal cell and urothelial cancers has made the development of liquid biopsy for these cancers strongly desirable. Liquid biopsy is less invasive than conventional tissue biopsy is, enabling frequent biopsies and, therefore, is considered effective for monitoring the treatment course. Circulating tumor cells (CTCs) are a representative liquid biopsy specimen. In the present study, we focused on developing our novel technology for capturing renal cell cancer (RCC)-CTCs using an anti-G250 antibody combined with new devices. Basic experiments of our technology showed that it was possible to detect RCC-CTC with a fairly high accuracy of about 95%. Also, RCC-CTC was identified in the peripheral blood of actual RCC patients. Additionally, during the treatment course of the RCC patient, change in the number of RCC-CTC was confirmed in one case. We believe that the technology we developed will be useful for determining the treatment efficacy and drug selection for the treatment of renal cell cancer (RCC). In order to solve issues such as thresholds setting of this technology, large-scale clinical trials are expected.
Morpho–Sedimentary Monitoring in a Coastal Area, from 1D to 2.5D, Using Airborne Drone Imagery
Authors: Mury Antoine , Collin Antoine , James Dorothée
Published: August 2019

Coastal areas are among the most endangered places in the world, due to their exposure to both marine and terrestrial hazards. Coastal areas host more than two-thirds of the world’s population, and will become increasingly affected by global changes, in particular, rising sea levels. Monitoring and protecting the coastlines have impelled scientists to develop adequate tools and methods to spatially monitor morpho-sedimentary coastal areas. This paper presents the capabilities of the aerial drone, as an “all-in-one” technology, to drive accurate morpho-sedimentary investigations in 1D, 2D and 2.5D at very high resolution. Our results show that drone-related fine-resolution, high accuracies and point density outperform the state-of-the-science manned airborne passive and active methods for shoreline position tracking, digital elevation model as well as point cloud creation. We further discuss the reduced costs per acquisition campaign, the increased spatial and temporal resolution, and demonstrate the potentialities to carry out diachronic and volumetric analyses, bringing new perspectives for coastal scientists and managers.
Multi-Sensor Assessment of the Effects of Varying Processing Parameters on UAS Product Accuracy and Quality
Authors: Pricope Narcisa G. , Mapes Kerry L. , Woodward Kyle D. , Olsen Steele F. , Baxley J. Britton
Published: August 2019

There is a growing demand for the collection of ultra-high spatial resolution imagery using unmanned aerial systems (UASs). UASs are a cost-effective solution for data collection on small scales and can fly at much lower altitudes, thus yielding spatial resolutions not previously achievable with manned aircraft or satellites. The use of commercially available software for image processing has also become commonplace due to the relative ease at which imagery can be processed and the minimal knowledge of traditional photogrammetric processes required by users. Commercially available software such as AgiSoft Photoscan and Pix4Dmapper Pro are capable of generating the high-quality data that are in demand for environmental remote sensing applications. We quantitatively assess the implications of processing parameter decision-making on UAS product accuracy and quality for orthomosaic and digital surface models for RGB and multispectral imagery. We iterated 40 processing workflows by incrementally varying two key processing parameters in Pix4Dmapper Pro, and conclude that maximizing for the highest intermediate parameters may not always translate into effective final products. We also show that multispectral imagery can effectively be leveraged to derive three-dimensional models of higher quality despite the lower resolution of sensors when compared to RGB imagery, reducing time in the field and the need for multiple flights over the same area when collecting multispectral data is a priority. We conclude that when users plan to use the highest processing parameter values, to ensure quality end-products it is important to increase initial flight coverage in advance.
The Introduction of Entropy and Information Methods to Ecology by Ramon Margalef
Authors: Sherwin William B , Prat i Fornells Narcis
Published: August 2019

In ecology and evolution, entropic methods are now used widely and increasingly frequently. Their use can be traced back to Ramon Margalef’s first attempt 70 years ago to use log-series to quantify ecological diversity, including searching for ecologically meaningful groupings within a large assemblage, which we now call the gamma level. The same year, Shannon and Weaver published a generally accessible form of Shannon’s work on information theory, including the measure that we now call Shannon–Wiener entropy. Margalef seized on that measure and soon proposed that ecologists should use the Shannon–Weiner index to evaluate diversity, including assessing local (alpha) diversity and differentiation between localities (beta). He also discussed relating this measure to environmental variables and ecosystem processes such as succession. Over the subsequent decades, he enthusiastically expanded upon his initial suggestions. Finally, 2019 also would have been Margalef’s 100th birthday.