bluuebunny/crossref_metadata_2025_split huggingface dataset:
Removal of Cu2+, Zn2+ and Pb2+ ions using a graphene-containing nanocomposite: a kinetic study
Authors: Babkin A , Burakova I , Burakov A , Kurnosov D , Galunin E , Tkachev A , Ali I 
Published: November 2019

Abstract
In the present paper, the urgent issue of removing heavy metal ions from aqueous solutions is considered by the example of extraction of Cu2+, Zn2+ and Pb2+ ions using an innovative sorbent - polyhydroquinone/graphene nanocomposite. Kinetics of the metal sorption on this material was studied. Moreover, the effect of solution pH on the sorption capacity of the nanocomposite was estimated. Besides, to elucidate mechanisms of kinetic removal and determine process parameters, experimental data were fitted to kinetic (pseudo-first- and pseudo-second-order, and Elovich) and diffusion (intraparticle and Boyd) models. The kinetic experiments showed that equilibrium is reached within 60 min. The effective diffusion coefficient values calculated according to the Boyd model were found to increase in the following sequence: Pb2+ (1.26 10-13 m2 s-1) < Zn2+ (3.74 10-13m2 s-1) < Cu2+ (4.24 10-13 m2 s-1). Finally, it was established that the metal sorption process is controlled by the internal diffusion of the sorbate into the bulk (volume) of the sorbent.
Rheological properties of “Vaseline – Carbon nanoparticles” model systems under conditions of non-destructive deformations”
Authors: Shilov M , Smirnova A , Gvozdev A , Rozhkova N , Dyachkova T , Burkov A , Stolbov D , Savilov S , Usol’tseva N 
Published: November 2019

Abstract
The paper presents experimental data on the rheological properties of “Vaseline – Carbon Nanoparticles” systems, which were obtained through oscillation tests. The nanoparticles used are multi-layered oxidized graphene (Gr), single- (SWCNTs) and multi-walled (MWCNTs) carbon nanotubes, as well as shungite nanocarbon (Sh). It was demonstrated that when carbon nanoparticles were added to the Vaseline (VM) at concentrations from 0.5 to 1.5 wt.%, the elasticity of the systems increased as compared with the pure VM, wherein the system containing 1.0 wt. % of MWCNTs was characterized by the greatest elasticity. All the studied carbon nanoparticles proved to be rheomodifiers. However, Gr, SWCNTs and MWCNTs acted essentially depending on their concentration in the vaseline system, resulting in both shortening and lengthening of the relaxation time. The natural shungite nanocarbon always led to the decrease of the relaxation time within the studied concentration range. The obtained results form an experimental basis for the development of scientific approaches to the production of lubricants operating in various friction modes
Kinetic of the dyes adsorption on a polyhydroquinone/graphene nanocomposite under dynamic conditions
Authors: Mkrtchyan E , Neskoromnaya E , Burakova I , Kurnosov D , Burakov A , Tkachev A , Ali I 
Published: November 2019

Abstract
Conducting adsorption experiments in a dynamic mode makes it possible to simulate process parameters as close to real conditions as possible. In the present work, the kinetics of the adsorption of some organic dyes (methylene blue, alizarin red S, and malachite green) on a novel polyhydroquinone/graphene nanocomposite, developed by the authors, were studied.It was established that the equilibrium of the adsorption system is achieved within 40, 120 and 57 min for methylene blue, alizarin red S and malachite green, respectively. Data processing using kinetic models showed that chemical interactions take place between the dye molecules and the active sites of the adsorbent during the adsorption. Besides, the contribution of the diffusion through the film on the adsorbent surface was also marked. The maximum adsorption capacity of the adsorbent was found to increase in the following sequence: malachite green (688.1 mg g-1) < methylene blue (2.610 mg g-1) < alizarin red S (2.923 mg g-1).
Impact of plasma treatment in CH4/N2 on the properties of reduced graphene oxide
Authors: Neustroev E P , Prokopiev A R , Timofeev V B , Popov V I , Kurkina I I , Davydova Z Y , Alekseev A A , Semenov S O 
Published: November 2019

Abstract
The effect of the two-step process on the properties of graphene oxide (GO) is studied. At the first stage, CH4 (or CH2+N2) plasma treatment was performed. The second one was heat treated at a temperature of 650° C. The formation of thin polycrystalline carbon films on the surface of graphene oxide was detected. The ratio of carbon to oxygen concentration corresponds to graphene oxide. Smooth surfaces of the films were detected by an atomic force microscope. Films have lower sheet resistance and higher carrier mobility than reduced GO (rGO) during the same heat treatment. An analysis of the Raman spectra shows that the formed films have larger graphene domains than the rGO. The presence of nitrogen in methane plasma leads to a decrease in the resistance and mobility of carriers in the carbon film.
Electromagnetic characteristics of coatings based on graphene oxide- and multi-walled carbon nanotubes Taunit-M in a wide range of frequencies
Authors: Suslyaev V , Tkachev A , Korovin E , Stolyarov R , Dorozhkin K , Chapaksov N , Dyachkova T , Blokhin A , Korshunov A 
Published: November 2019

Abstract
The frequency dependences of the reflection, transmission, and absorption coefficients of samples of materials based on graphene oxide and Taunit-M multi-walled carbon nanotubes were measured. Graphene oxide and carbon nanotubes are glued with acrylic adhesive to a double-sided sheet of plastic. The method of free space is used to measure in the frequency range 35 - 260 GHz. It is shown that the addition of MWCNT of 30 weight percent reduces the transmission coefficient by more than ten times.
Adsorption of Cu2+, Zn2+and Pb2+ ions on a novel graphene-containing nanocomposite: An isotherm study
Authors: Babkin A , Burakova I , Burakov A , Kurnosov D , Galunin E , Tkachev A , Ali I 
Published: November 2019

Abstract
The present research is dedicated to the problem of adsorption purification of aquatic media from toxic heavy metal ions. To extract some of these species (Cu2+, Zn2+, and Pb2+) from aqueous solutions, a novel material - polyhydroquinone/graphene nanocomposite – was used as adsorbent. Its adsorption/desorption performance was assessed through isotherm studies. The following process parameters were determined: equilibrium metal concentrations in solution, metal distribution coefficients, percentage desorption, and adjusted metal distribution coefficients. Besides, based on experimental data, adsorption isotherms were constructed, from which it was possible to determine the maximum adsorption capacity of the nanocomposite regarding each heavy metal ion (Pb2+ - 1350 mg-1; Cu2+ - 800 mg g-1, and Zn2+ -300 mg g-1). In order to elucidate adsorption-desorption mechanisms occurring in the considered adsorbate/adsorbent systems and the process nature, the data were fitted to different isotherm models: empirical (Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich), and combined (single- and dual-site Langmuir-Freundlich). All the models provided satisfactory fits to the data, thereby making it possible to assume heterogeneity of adsorption sites on the adsorption surface, and the irreversibility of the adsorption process.
Enhancing the efficiency of dye-sensitized solar cell by increasing the light trapping and decreasing the electron-hole recombination rate due to Ag@TiO2 core-shell photoanode structure
Authors: Fallah Milad , Maleki Iraj , Zamani-Meymian Mohammad-Reza , Abdi Yaser 
Published: November 2019

Abstract
In this research, efficiency enhancement of dye-sensitized solar cell (DSSC) with Ag doped TiO2 core-shell (C–S) as plasmonic photoanode structure, abbreviated as Ag@TiO2, was investigated using Sol-Gel- Dr Blade method. Different amount of Ag in two different thick of photoanode were applied to enhance the light absorption for high-performance DSSCs. The localized surface plasmonic resonance (LSPR) effect of Ag@TiO2 showed an improvement in light trapping and power conversion efficiency (PCE) of developed DSSCs. Conforming to the conclusions under AM 1.5 spectrum, the prepared plasmonic solar cells exhibited 21.9% and 41.46% increase in PCE for 13 μm and 8.4 μm thick of photoanode, respectively.
RETRACTED: Green synthesis of Cefadroxil loaded chitosan/PVA nanofibers by freeze drying
Authors: Iqbal Haroon , Mahar Faraz Khan , Razzaq Anam , Kamal Robia , Khan Naveed Ullah , Ullah Kifayat , Iqbal Shahid 
Published: November 2019

Abstract
Freeze drying (lyophilization) is a simple method of nanofibers preparation which has been extensively used in the biological application as well as in pharmaceutical production to improve the mean life of labile drug. Cefadroxil drug loaded chitosan/PVA nanofibers (CFX-CPNFs) were successfully fabricated by freeze drying method. The maximum loading capacity (%) and entrapment efficiency (%) of drug were achieved up to 12.3% and 45% respectively. The release profile of drug was studied within 6 h. The drug release profile was analyzed by Korsmeyer-Peppas and Higuchi’s models, the drug delivery system best fitted to Korsmeyer-Peppas model. The antimicrobial activity of CFX-CPNFs was analyzed against 16 strains of staphylococcus bacteria, which showed excellent results and the zone of inhibition was twice than CFX drug.
Synthesis of SCMNPs@imine/SO3H magnetic nanocatalyst by chlorosulfonic acid as sulfonating agents and their application for the preparation of 12-aryl-8,9,10,12-tetrahydrobenzo[a]xanthen-11-one and 1,8-dioxooctahydroxanthene derivatives
Authors: Zhou Ji , Liu Dan , Wu Fengshou , Xiong Yun , Ashraf Muhammad Aqeel 
Published: November 2019

Abstract
In this survey, new recoverable sulfonated magnetic nanocatalysts (SCMNPs@imine/SO3H) was synthesized by covalent attachment of a Schiff base ligand on the surface of SCMNPs@APTES/sucanh through reaction with 4-[(Pyridin-2-ylmethylene)-amino]-phenol and subsequent reaction with chlorosulfonic acid. The synthesized nanocatalyst was characterized by several techniques such as FTIR, TGA, VSM, XRD, UV–vis and EDX analysis. The nanocatalyst was evaluated in the preparation of 12-aryl-8,9,10,12-tetrahydrobenzo[a]xanthen-11-one and 1,8-dioxooctahydroxanthene derivatives with pharmacologically and biologically remarkable activity. 12-aryl-8,9,10,12-tetrahydrobenzo[a]xanthen-11-one and 1,8-dioxooctahydroxanthene derivatives were respectively prepared via one-pot, three-component reactions of 2-naphthol, dimedone and aldehydes, as well as the reaction between dimedone and aldehydes in the presence of SCMNPs@imine/SO3H under solvent-free conditions. The merits of this synthesis are high-to-excellent yields, short reaction time, mild basic conditions and high catalytic activity. Also, the SCMNPs@imine/SO3H with suitable magnetic strength can be easily separated from the reaction solution using an external magnetic field.
Effect of Mg addition on microstructure and mechanical properties of Al-Si-Cu-Fe alloy with squeeze casting
Authors: Jiang Bo , Xu Song , Xu Hong-Yu , Hu Mao-Liang , He Ying-Jie , Ji Ze-Sheng 
Published: November 2019

Abstract
In this work, the Al-10Si-2.5Cu-0.8Fe alloy was used as the base alloy to squeeze casting with different content Mg-10Al master alloy addition. The effects of microstructure and mechanical properties were investigated by XRD, OM, SEM, and tensile test analysis. The results show that with the increase of Mg addition, the morphology of eutectic Si in the alloy changes from strip to fiber and the size is obviously reduced. Al8Mg3FeSi6 phase in the microstructure gradually grows, and the splitting effect on the matrix structure is increased. The tensile strength and elongation of the alloy increased first and then decreased with the increase of Mg content. When the Mg content is 1.38%, the tensile strength of the alloy reached a maximum of 289 MPa and the elongation is 2.24%. The hardness of the alloy gradually increases. When the Mg content is 2.51%, the hardness reaches 121.8 HV. The cleavage surface in the fracture becomes fine with the increase of Mg content, the number of dimples increases, and the fracture mode transitions from quasi-cleavage fracture to brittle fracture.
Facile development and structural investigations of HAp and HAp/Ta nanostructures: Photocatalytic activity against Turq blue GL dye
Authors: Manoj Murugesan , Mangalaraj Devanesan , Meena Palaniappan , Yuan Aihua 
Published: November 2019

Abstract
The rising awareness of the need for a healthy environment for living systems has led to an increasing demand for suitable catalyst materials for wastewater treatment. In this connection, in the present work, the catalyst materials Hydroxyapatite and Hydroxyapatite/Tantalum (HAp/Ta) core–shell nanostructured particles were prepared through a facile nanoprecipitation method without a surfactant, chelating agents and/or ligands. The prepared nanostructured particles were characterised with the help of several analytical techniques namely XRD, FESEM, TEM, EDS, FTIR, Raman, XPS and BET. The calculated average crystallite size of HAp was found to be 26 nm and the core–shell nanorod morphology was corroborated through FESEM and TEM technique. The average length and width were found to be 44 and 16 nm respectively. The specific surface area (SSA), microporous nature and pore volume were investigated through the N2 adsorption isotherm method. The photocatalytic activity of the prepared HAp and HAp/Ta core–shell nanostructured particles was investigated on frequently used dyeing industrial dyes Turq blue GL under UV irradiation. The recorded results evince that the HAp/Ta core–shell nanorods have more catalytic activity than pure HAp and can be used as a nanophotocatalyst for industrial waste water treatment process to curb water pollution and to protect the environment.
Structural and electronic properties of the iron pnictide compound EuFe2As2 from first principles
Authors: Omboga N K , Otieno C O 
Published: November 2019

Abstract
We report results of the electronic and mechanical structure properties of the iron pnictide compound EuFe2As2, at zero pressure. The open source computer code Quantum Espresso, which incorporates the Density Functional Theory (DFT), Pseudo Potentials (PP) and the Plane Wave (PW) were used to perform calculations from first principles. Projector-Augmented Wave (PAW) Pseudo Potentials were used in these calculations. The Density of States exhibits a sizeable superconducting gap and the band structure has no bandgap. Calculations were performed from scratch.
Impact of H2 gas on disruptive birefringence optical fibers with embedded Palladium particles for developing robust sensors
Authors: Aazi Mohamed , Kudinova Maryna , Kinet Damien , Auguste Jean-Louis , Delépine-Lesoille Sylvie , Mégret Patrice , Humbert Georges 
Published: November 2019

Abstract
Optical fiber sensors of hydrogen gas (H2) are conventionally based on the reaction of a sensitive material deposited on the surface of a fiber. Long-term applications of H2 monitoring require more robust configurations, less sensitive to the degradations of the sensitive layer. To overcome this issue, we develop disruptive polarisation-maintaining optical fibers composed of a sensitive material (Palladium, Pd) integrated into the silica cladding. We present the development of two Panda-type optical fibers with or without embedded Pd particles. These fibers have been fabricated for evaluating, through the measurement of the birefringence, the contribution of Pd particles on the detection of H2 gas. We have specially developed a gas chamber for measuring on-line the detection of H2 during its diffusion into the fiber. Dynamic comparisons between both fibers demonstrate the contribution of Pd particles resulting in a faster response time (of about 20 h for our experimental conditions). These results pave the way to the realization of robust optical fibers with enhanced sensitivity to H2 gas for developing sensing systems compatible with long-term hydrogen monitoring applications in extreme and harsh environments, such as radioactive waste repositories.
CRISPR/Cas9 technology: towards a new generation of improved CAR-T cells for anticancer therapies
Authors: Ureña-Bailén Guillermo , Lamsfus-Calle Andrés , Daniel-Moreno Alberto , Raju Janani , Schlegel Patrick , Seitz Christian , Atar Daniel , Antony Justin S , Handgretinger Rupert , Mezger Markus 
Published: November 2019

AbstractChimeric antigen receptor (CAR)-modified T cells have raised among other immunotherapies for cancer treatment, being implemented against B-cell malignancies. Despite the promising outcomes of this innovative technology, CAR-T cells are not exempt from limitations that must yet to be overcome in order to provide reliable and more efficient treatments against other types of cancer. The purpose of this review is to shed light on the field of CAR-T cell gene editing for therapy universalization and further enhancement of antitumor function. Several studies have proven that the disruption of certain key genes is essential to boost immunosuppressive resistance, prevention of fratricide, and clinical safety. Due to its unparalleled simplicity, feasibility to edit multiple gene targets simultaneously, and affordability, CRISPR/CRISPR-associated protein 9 system has been proposed in different clinical trials for such CAR-T cell improvement. The combination of such powerful technologies is expected to provide a new generation of CAR-T cell-based immunotherapies for clinical application.
Midget retinal ganglion cell dendritic and mitochondrial degeneration is an early feature of human glaucoma
Authors: Tribble James R , Vasalauskaite Asta , Redmond Tony , Young Robert D , Hassan Shoaib , Fautsch Michael P , Sengpiel Frank , Williams Pete A , Morgan James E 
Published: November 2019

AbstractGlaucoma is characterized by the progressive dysfunction and loss of retinal ganglion cells. However, the earliest degenerative events that occur in human glaucoma are relatively unknown. Work in animal models has demonstrated that retinal ganglion cell dendrites remodel and atrophy prior to the loss of the cell soma. Whether this occurs in human glaucoma has yet to be elucidated. Serial block face scanning electron microscopy is well established as a method to determine neuronal connectivity at high resolution but so far has only been performed in normal retina from animal models. To assess the structure–function relationship of early human glaucomatous neurodegeneration, regions of inner retina assessed to have none-to-moderate loss of retinal ganglion cell number were processed using serial block face scanning electron microscopy (n = 4 normal retinas, n = 4 glaucoma retinas). This allowed detailed 3D reconstruction of retinal ganglion cells and their intracellular components at a nanometre scale. In our datasets, retinal ganglion cell dendrites degenerate early in human glaucoma, with remodelling and redistribution of the mitochondria. We assessed the relationship between visual sensitivity and retinal ganglion cell density and discovered that this only partially conformed to predicted models of structure–function relationships, which may be affected by these early neurodegenerative changes. In this study, human glaucomatous retinal ganglion cells demonstrate compartmentalized degenerative changes as observed in animal models. Importantly, in these models, many of these changes have been demonstrated to be reversible, increasing the likelihood of translation to viable therapies for human glaucoma.
Antipneumococcal Seroprotection Years After Vaccination in Allogeneic Hematopoietic Cell Transplant Recipients
Authors: Robin Christine , Bahuaud Mathilde , Redjoul Rabah , Jeljeli Mohamed , Leclerc Mathieu , Cabanne Ludovic , Beckerich Florence , Pautas Cécile , Maury Sébastien , Cordonnier Catherine 
Published: November 2019

Abstract

Background
International guidelines recommend vaccinating allogeneic hematopoietic cell transplant (HCT) recipients at 3 months after transplant, giving 3 doses of pneumococcal conjugate vaccine (PCV) followed by either a dose of 23-valent pneumococcal polysaccharide vaccine (PSV23) or a fourth PCV dose in the case of graft-versus-host disease (GvHD). However, the long-term immunity after this regimen is unknown, and there is no recommendation from 24 months after transplant regarding boosts. Our objective was to assess the antipneumococcal antibody titers and seroprotection rates of allogeneic HCT recipients years after different schedules of vaccination.

Methods
We assessed 100 adult HCT recipients a median of 9.3 years (range: 1.7–40) after transplant. All patients had received at least one dose of PCV and were assessed for antipneumococcal immunoglobulin G (IgG) antibody titers against the 7 serotypes shared by PCV7, PCV13, and PSV23. Sixty-six percent of the patients had been vaccinated according to the current guidelines.

Results
Considering an IgG titer ≥ 0.35 µg/mL as protective for each serotype, the seroprotection rate was 50% for 7/7 serotypes and 70% for 5/7 serotypes, with no differences between the different vaccination schedules. The lack of seroprotection was associated with a transplant performed not in complete remission or from a cord-blood unit, a relapse after transplant, or chronic GvHD at assessment.

Conclusion
Because only half of the vaccinated patients had long-term protection, pending prospective studies defining the best boost program after the initial one, we recommend the assessment of specific IgG titers starting from 24 months to decide for further doses.
Genomic background of a colistin-resistant and highly virulent MCR-1-positive Escherichia coli ST6395 from a broiler chicken in Pakistan
Authors: Mohsin Mashkoor , Azam Mariya , ur Rahman Sajjad , Esposito Fernanda , Sellera Fábio P , Monte Daniel F , Cerdeira Louise , Lincopan Nilton 
Published: November 2019

ABSTRACT
The convergence of high virulence and multidrug resistance (MDR) in Gram-negative pathogens circulating at the human–animal interface is a critical public health issue. We hereby report the genomic characteristics and virulent behavior of a colistin-resistant Escherichia coli, serotype ONT:H26, belonging to ST6395, isolated from a healthy broiler in Pakistan. This strain harbored multiple antimicrobial resistance genes, including mcr-1.1 and blaCARB-2, besides cma (colicin M) and astA [heat-stable enterotoxin 1 (EAST1) toxin] virulence genes. In vivo experiments carried out with the Galleria mellonella infection model revealed that MCR-1-positive E. coli ST6395 killed 96.4% of the larvae at 18 hour post-infection. Interplay between resistance and virulence in clinically important pathogens could be a potential threat, representing a serious challenge to global public health.
A Motion of No Confidence: Leadership and Rebel Fragmentation
Authors: Doctor Austin C 
Published: November 2019

AbstractWhy do rebel organizations splinter into competing factions during civil war? To explain this outcome, I leverage variation in rebel leadership. I argue that rebel leaders draw on their pre-war experiences—i.e., their military and political experiences—to manage their organizations during conflict. These experiences bear unique patterns of rebel management and, thus, corresponding risks of fragmentation. Empirical evidence comes from a two-stage research design and original data featuring over 200 rebel leaders from 1989 to 2014. In the first stage, I estimate the probability of group fragmentation with a series of logistic regression models. In the second stage, I use Cox proportional-hazards models to estimate leadership effects on the rate of group fragmentation. Results indicate that variation in rebel leadership corresponds with unique risks of fragmentation. In particular, the results suggest that leaders with real military experience are best equipped to maintain group cohesion. This study offers insight into the processes by which rebel groups splinter into armed factions. In addition, it makes an important contribution to the broader discussion on the roles of structure and agency in shaping the dynamics of civil war.