bluuebunny/crossref_metadata_2025_split huggingface dataset:
Removal of titanium dioxide nanoparticles from wastewater using traditional chemical coagulants and chitosan
Authors: Punzi Vito L. , Kungne Vanessa Z. , Skaf Dorothy W. 
Published: February 2020

AbstractAlum and ferric chloride were used individually as coagulants to remove P25 TiO2 nanoparticles (NPs) from a simulated wastewater. Previous studies have addressed the use of alum, polyaluminum chloride, chitosan, and polyaluminum chloride with chitosan for coagulation of NPs. A goal of this study was to reduce chemical usage associated with wastewater treatment by examining the coagulation effectiveness of chitosan in conjunction with alum. To further reduce chemical consumption during coagulation, the initial solution pH was limited to 6 or 8. A range of alum doses removed NPs from pH 8 wastewater to achieve residual turbidity <1 NTU. NP removal from pH 6 solutions produced water with residual turbidity <2 NTU only at lower initial NP concentrations. For pH 8 solutions, ferric chloride produced treated water with residual turbidity <1 NTU but at higher doses than required for alum. While chitosan alone did not significantly reduce turbidity, the use of alum and chitosan together reduced the optimal alum dose by 10% and also reduced alum treatment acidification. Therefore, the use of chitosan in coagulation can potentially reduce chemical usage during water treatment and the energy and water consumption associated with chemical production. Use of alum with low chitosan concentrations produces faster settling floc, which can potentially reduce settling tank volume and produce an effluent containing lower aluminum concentrations.
Multi‐site aerodynamic optimization of wind turbine blades for maximum annual energy production in East Iran
Authors: Azizi Mahdi , Jahangirian Alireza 
Published: February 2020

AbstractAerodynamic optimization of a horizontal axis wind turbine blade is performed for maximizing total annual energy production in three different sites located in the east part of Iran. While most researches have focused on the optimization of wind turbine blades for a specific location or air velocity, the main objective in practical problems is to find the best single design for multiple locations giving the highest energy output. The current paper addresses this issue and shows that multi‐site optimization of wind turbine blades is the key to maximizing energy extraction at multiple sites while reducing the manufacturing costs by proposing one optimum blade for all sites. In order to achieve this goal, the known Riso wind turbine blade is used as the base geometry and is optimized using a modified blade element momentum (BEM) theory and genetic algorithm. The objective function is maximizing sum of energy production at the selected sites. Blade twist and chord length distributions are chosen as design parameters. By running various optimization cases, it is shown that the multi‐site optimum blade has the highest sum of annual energy production by 4.45% increase compared with the Riso wind turbine blade.
Evolution of mining‐induced stress in fully mechanized top‐coal caving under high horizontal stress
Authors: Huo Yuming , Song Xuanmin , Sun Zedong , Wang Zhonglun , Li Haocheng 
Published: February 2020

AbstractIn fully mechanized top‐coal caving (FMTC), the effects of coal caving are closely related to the degree of damage to the top‐coal which is determined by the stress state therein. Therefore, research into the evolution of mining‐induced stress field is key to understanding failure mechanisms of top‐coal. By taking the 12 309 FMTC face in Wangjialing Coal Mine (China) as the engineering background and using field measurement and numerical simulation, we studied the evolution of the principal stress field in FMTC under high horizontal stress. The research results demonstrated that in situ stress in Wangjialing Coal Mine was a high horizontal stress and lateral pressure coefficients in the north‐south and east‐west directions were 1.52 and 0.45, respectively. Under the influence of mining, principal stresses were concentrated in front of the coal wall, with concentration factors of 2.26, 2.24, and 2.85, respectively. The minimum principal stress in unconstrained sides of the top‐coal in the roof‐control zone was tensile. The directions of intermediate and minimum principal stresses in the top‐coal were more sensitive to the influence of mining compared to the maximum principal stress. During rotation of the principal stress direction in top‐coal, the location (19 m in front of the coal wall) where the maximum and intermediate principal stresses were equal and the location of the coal wall are key positions.
Single-Pot Method for the Collection and Preparation of Natural Water for Microplastic Analyses: Microplastics in the Mississippi River System during and after Historic Flooding
Authors: Scircle Austin , Cizdziel James V. , Missling Klara , Li Libby , Vianello Alvise 
Published: February 2020

Abstract
We describe a simple single-pot method for collection and preparation of natural water for microplastic analyses. The method prepares samples in the same vessel (mason jars) that they are collected in right up until the microplastics are transferred onto filters or spectroscopic windows for analyses. The method minimized contamination, degradation, and losses, while increasing recoveries and throughput when compared with conventional sieving. We applied it to surface grab samples collected from the Mississippi River and its major tributaries during and after historic flooding in 2019. Microplastics (&gt;~30 µm) were quantified using Nile red fluorescence detection, and a small subset of samples were identified by micro-Fourier transform infrared imaging spectroscopy. Concentrations were lower during the flooding, likely due to dilution. Concentrations ranged from approximately 14 microplastics/L in the Tennessee River during flooding to approximately 83 microplastics/L in the Ohio River during low-flow (summer) conditions. Loads of microplastics tended to increase downriver and ranged from approximately 87 to approximately 129 trillion microplastics/d near New Orleans. Most of the microplastics (&gt;60%) were in the lower size fraction (~30–90 µm) and consisted primarily of fragments (~85%), followed by fibers (~8%) and beads (~7%), with polyester, polyethylene, polypropylene, and polyacrylate as the primary microplastic types. Overall, we demonstrate that the single-pot method is effective and versatile and, because it uses relatively inexpensive and easily assembled materials, can be adapted for microplastic surveys worldwide, especially those involving sample collection by volunteers from the community and schools. Environ Toxicol Chem 2020;39:986–995. © 2020 SETAC
Abstract
Impact of flooding on microplastics in the Mississippi River system.
Regulation and signaling of the GPR17 receptor in oligodendroglial cells
Authors: Lecca Davide , Raffaele Stefano , Abbracchio Maria P. , Fumagalli Marta 
Published: February 2020

AbstractRemyelination, namely, the formation of new myelin sheaths around denuded axons, counteracts axonal degeneration and restores neuronal function. Considerable advances have been made in understanding this regenerative process that often fails in diseases like multiple sclerosis, leaving axons demyelinated and vulnerable to damage, thus contributing to disease progression. The identification of the membrane receptor GPR17 on a subset of oligodendrocyte precursor cells (OPCs), which mediate remyelination in the adult central nervous system (CNS), has led to a huge amount of evidence that validated this receptor as a new attractive target for remyelinating therapies. Here, we summarize the role of GPR17 in OPC function, myelination and remyelination, describing its atypical pharmacology, its downstream signaling, and the genetic and epigenetic factors modulating its activity. We also highlight crucial insights into GPR17 pathophysiology coming from the demonstration that oligodendrocyte injury, associated with inflammation in chronic neurodegenerative conditions, is invariably characterized by abnormal and persistent GPR17 upregulation, which, in turn, is accompanied by a block of OPCs at immature premyelinating stages. Finally, we discuss the current literature in light of the potential exploitment of GPR17 as a therapeutic target to promote remyelination.
Interleukin‐6 signaling requires only few IL‐6 molecules: Relation to physiological concentrations of extracellular IL‐6
Authors: Hansen Morten B. 
Published: February 2020

AbstractIntroductionThe aim of this study was to give quantitative insight into the number of cytokine molecules needed to activate a target cell and relate this to the physiological consequences of the amounts of cytokines typically detectable in humans. As a model system blood interleukin‐6 (IL‐6) was chosen since this cytokine is one of the most studied and clinically monitored cytokines, and because of the tools for the present investigations such as fully bioactive iodinated recombinant IL‐6, cellular cytokine binding assays, and bioassays have been thoroughly validated.MethodsThe key intermediates of the basic equilibrium principles that govern cytokine binding and exchange were deduced and applied on concrete estimations of cellular and extracellular IL‐6 binding in the bloodstream based on experimental binding data and data from the literature. In parallel, in vitro cellular IL‐6 binding data was substantiated by paired measurements of IL‐6 bioactivity on IL‐6 sensitive B9 hybridoma cells.ResultsBlood leucocytes and B9 cells expressed 50 to 300, 10 to 20 picomolar affinity, IL‐6 binding sites per cell and at physiological concentrations of IL‐6 less than 10 IL‐6 molecules seemed to be bound to blood cells. Nonetheless, binding off as few as four IL‐6 molecules per cell seemed to result in statistically significant bioactivity, whereas binding of 16 IL‐6 molecules triggered extensive cellular responses.ConclusionTogether, the estimations and the measurements support the notion that target cells with more than 100 bioactive cytokine receptors per cell, such as T cells and hepatocytes, are likely to be under steady and substantial cytokine‐induced endocrine activation.
In vivo evaluation of an electrospun and 3D printed cellular delivery device for dermal wound healing
Authors: Clohessy Ryan M. , Cohen David J. , Stumbraite Karolina , Boyan Barbara D. , Schwartz Zvi 
Published: February 2020

AbstractBurns and chronic wounds are especially challenging wounds to heal. In efforts to heal these wounds, physicians often use autologous skin grafts to help restore mechanical and barrier functionality to the wound area. These grafts are, by nature, limited in availability. In an effort to provide an alternative, we have developed an electrospun wound dressing designed to incorporate into the wound with the option to deliver a cellular payload. Here, a blend of poly(glycolic acid) and poly(ethylene glycol) was electrospun as part of a custom fabrication method that incorporated 3D printed poly(vinyl alcohol) sacrificial elements. This preparation is unique compared to traditional electrospinning as sacrificial elements provide an internal void space for an injectable payload to be delivered to the wound site. When the construct was tested in vivo (full thickness excisional skin wounds), wound closure was slightly delayed by the presence of the scaffold in both normal and challenged wounds. Quality of healing was improved in normal wounds as measured by histomorphometrics when treated with the construct and exhibited increased neovascularization. Our results demonstrate that the extracellular matrix‐like scaffold developed in this study is beneficial to healing of full thickness skin defects and may benefit challenged wounds.
Heparin‐induced lipoprotein precipitation apheresis in dyslipidemic patients: A multiparametric assessment
Authors: Merolle Lucia , Marraccini Chiara , Latorrata Alessia , Quartieri Eleonora , Farioli Daniela , Scarano Luca , Fasano Tommaso , Bergamini Stefania , Bellei Elisa , Monari Emanuela , Tomasi Aldo , Di Bartolomeo Erminia , Baricchi Roberto , Pertinhez Thelma A. 
Published: February 2020

AbstractLow‐density lipoprotein (LDL) apheresis (LA) selectively eliminates lipoproteins containing apolipoprotein B 100 (ApoB100) on patients affected by severe dyslipidemia. In addition to lowering lipids, LA is thought to exert pleiotropic effects altering a number of other compounds associated with atherosclerosis, such as pro‐ and anti‐inflammatory cytokines or pro‐thrombotic factors. More knowledge needs to be gathered on the effects of LA, and particularly on its ability to modify blood components other than lipids. We performed a multiparametric assessment of the inflammatory, metabolic and proteomic profile changes after Heparin‐induced lipoprotein precipitation (H.E.L.P.) apheresis on serum samples from nine dyslipidemic patients evaluating cholesterol and lipoproteins, plasma viscosity and density, metabolites, cytokines, PCSK9 levels and other proteins selectively removed after the treatment. Our results show that H.E.L.P. apheresis is effective in lowering lipoprotein and PCSK9 levels. Although not significantly, complement and inflammation‐related proteins are also affected, indicating a possible transient epiphenomenon induced by the extracorporeal procedure.
Iodine substituted phosphorus corrole complexes as possible photosensitizers in photodynamic therapy: Insights from theory
Authors: Alberto Marta Erminia , De Simone Bruna Clara , Liuzzi Simona , Marino Tiziana , Russo Nino , Toscano Marirosa 
Published: February 2020

AbstractThe search for new dyes to be used as photosensitizers in photodynamic therapy (PDT) is a field of great interest from both experimental and theoretical viewpoints. In this study, the main photophysical properties (excitation energies, singlet‐triplet energy gap, and spin orbit coupling matrix elements) of some unsubstituted and iodine substituted phosphorus corrole complexes have been determined by using density functional theory and its time‐dependent formulation. Results show that these compounds can be proposed as photosensitizers in PDT. The heavy atom effects have been rationalized on the basis of El‐Sayed rules.
The Cascade C─H functionalization with sequential hydroxylation and oxidation through heterogeneous BINAP‐copper on hydrotalcite
Authors: Zhang Qiaohong , Wang Huibin , Hu Wenkang , Xu Xiaqing , Xu Zhaojun , Chen Chen , Wang Dawei 
Published: February 2020

AbstractBACKGROUNDAromatic thioether derivatives exist widely in natural products and have significant applications in modern synthesis and the pharmaceutical industry; for example, 2‐sulfanylphenols and arylthioquinones are important intermediates in the processing of anticancer, antibiotic, antivirus and antimalarial drugs. Direct C─H hydroxylation was considered as one of the efficient methods for the synthesis of these compounds. Homogeneous transition metal catalysts usually were used through a cross‐coupling of halogen‐substituted phenols with thiophenols. However, from the perspectives of sustainable development and easy recovery, it is necessary to develop an efficient and recoverable catalytic system to realize the synthesis of aromatic thioether derivatives with good efficiency and recyclability.RESULTSThe heterogeneous catalyst [Cu(binap)I]2@HT in the present work showed good catalytic activity for the C─H hydroxylation of benzenethiol and phenylboronic acid. The catalytic system was tolerant to various substituents including alkyl, alkoxy, ester, halogen or trifluoromethyl on the phenyl ring of the thiophenols or arylboric acids. In addition to electron‐donating groups, the products with strong electron‐withdrawing groups, such as methyl formylate and trifluoromethyl also were achieved with good yields at 90 °C for 12 h (68% and 66%, respectively). Repeated experiment results showed that the catalyst could be reused at least five times without obvious decrease in catalytic activity.CONCLUSIONA BINAP‐Cu complex supported on hydrotalcite was prepared and used as a heterogeneous catalyst for the C─H activation of thiophenol under mild reaction conditions. Through a cascade C─H hydroxylation and further oxidation process, 2‐Sulfanylphenols and arylthioquinones could be obtained with moderate‐to‐good yields for a series of 2‐(phenylthio)phenol derivatives using the heterogeneous catalyst [Cu(binap)I]2@HT. In addition, this heterogeneous catalyst showed good recylbility. © 2020 Society of Chemical Industry
On the Role of DGAT1 in Seed Glycerolipid Metabolic Network and Critical Stages of Plant Development in Arabidopsis
Authors: Wang Liping , Li Qiang , Xia Qun , Shen Wenyun , Selvaraj Gopalan , Zou Jitao 
Published: February 2020

AbstractStudies on the model plant Arabidopsis thaliana have uncovered the identities of most enzymatic components involved in seed storage lipid biosynthesis. However, much remains to be learned on how pathway interactions operate in the seed metabolic network. In this study, we dissected seed glycerolipid molecular compositional changes in the Arabidopsis mutant deficient in diacylglycerol acyltransferase 1 (DGAT1). Our results indicate that metabolic adjustments occurred in both phosphatidylcholine synthesis and deacylation in developing seeds. Ultrastructural changes of perturbed oil and protein bodies were also evident in cotyledon parenchyma cells. To unmask the physiological and developmental role associated with DGAT1‐mediated neutral lipid biosynthesis, we attempted to combine dgat1 mutation with lpcat2 that harbors a defect in lysophosphatidylcholine acyltransferase 2 (LPCAT2). Disruption in both DGAT1 and LPCAT2 led to an apparent defect in pollen development that manifested as pollen sterility. Collectively, our results highlight a role of DGAT1 in both storage lipid synthesis and plant development.
Effect of number of layers on erosion, corrosion, and wear resistance of multilayer Cr–N/Cr–Al–N coatings on AISI 630 stainless steel
Authors: Olia H. , Ghobadi M. , Danaee Iman , Onsori S. 
Published: February 2020

AbstractIn the present study, multilayered Cr–N/Cr–Al–N coatings were prepared by cathodic arc physical vapor deposition (PVD) with different numbers of layers and the same total thickness on AISI 630 steel in an attempt to improve the wear and erosion–corrosion resistance. Structural analysis of the coatings was performed by field scanning electron microscopy, X‐ray diffraction (XRD), and energy‐dispersive spectroscopy. Depth profiles and roughness parameters of worn surfaces were calculated after erosion and wear tests. XRD indicated that nitride compounds were formed in multilayer coatings by PVD. The Cr–N/Cr–Al–N coating exhibited superior corrosion resistance compared with AISI 630 substrate. The erosion–corrosion results revealed that the smoothest wear track with the minimum erosion rate and wear depth was obtained for five‐ and seven‐layered coatings. The failure mechanism of the bare substrate was influenced by plastic deformation via cutting and plowing, while the failure mechanism for coated samples was chipping and delamination. According to the wear results, the multilayer coatings showed a lower friction coefficient and better surface morphology that demonstrated their high ability for wear protection.
A minimalist approach to polarization resistance measurements in a reinforced concrete structure
Authors: Keßler Sylvia , Sagüés Alberto A. 
Published: February 2020

AbstractIn the curriculum of future civil engineers, electrochemical concepts are often neglected, even though this knowledge is essential to adequately maintain reinforced concrete structures in a chloride‐exposed environment. Experiments are necessary to consolidate key theoretical concepts, but laboratory experience often involves complex and expensive electronic equipment that may obscure the basic procedures at work. This paper presents a simple minimalistic electrochemical test for polarization resistance measurements by which students can learn basic concepts of corrosion electrochemistry and estimate the corrosion rate as a key parameter for estimation of the remaining service life of concrete structures. The focus is on avoiding unnecessary complications and providing an experiment that can be readily implemented for a wider student reach.
Diphasic Worsening of Freezing of Gait in Parkinson's Disease
Authors: Perez Parra Sahyli , McKay J. Lucas , Factor Stewart A. 
Published: February 2020

ABSTRACTBackgroundThe relationship between freezing of gait (FOG) and levodopa response is complex. Some patients respond, some have no response and in some patients levodopa causes FOG. We present 2 cases demonstrating a diphasic worsening of FOG after levodopa dosing.CasesTwo PD patients with FOG were examined during the practically defined off state, the transition from off to on (15 and 22 minutes postdose), and in the full on state (45 and 60 minutes postdose). FOG was measured using Movement Disorder Society–Unified Parkinson's Disease Rating Scale part III, item 11: freezing of gait. Both patients experienced worsening of FOG during the transition followed by improvement during the on state. Case 1 had serum levodopa levels measured. Videos are provided.ConclusionsTo our knowledge, this diphasic pattern of worsening of FOG has not been previously reported. The cause of this phenomenon is unknown but may relate to an inhibitory action of subthreshold levels of levodopa.
Numerical simulation of terahertz radiation in photoconductive antenna
Authors: Xiong Zhong‐gang , Deng Hu , Chen Jun‐xue , Chen Lin‐yu , Liu Quan‐chen , Guo Jin , Shang Li‐ping 
Published: February 2020

AbstractThe terahertz radiation in photoconductive antenna involves the multiple physical processes. It is a challenge to simulate the terahertz radiation in photoconductive antenna. A numerical simulation tool for the photoconductive antenna is very necessary to effectively design and optimize the terahertz radiation source. In this paper, by introducing the auxiliary equations describing the dynamic behaviors of carriers in the semiconductor into the Maxwell's equations, we use the three‐dimensional finite‐difference time‐domain method to solve these equations and obtain the time‐domain solutions in the nearfield of antenna. A near‐to‐far‐field transformation in the layered medium is adopted in order to obtain the wave pattern of terahertz radiation in the far field. Assisted by the developed simulation tool, the terahertz time‐domain waveforms and other terahertz radiation characteristics for the photoconductive antenna can be presented. By comparing with the experimental results reported in the references, the validity and reliability of these physical models and the developed simulation tool are demonstrated. More importantly, the results given in this paper will be of great significance to design and optimize the radiation performance of photoconductive antenna with different structures.