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Reduced graphene oxide (RGO) reinforced Mg biocomposites for use as orthopedic applications: Mechanical properties, cytocompatibility and antibacterial activity

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Journal of Magnesium and Alloys 2022年第12期10卷 3612-3627页

作者： somayeh abazari Ali Shamsipur HamidRezaBakhsheshi-Rad Department of Materials and Metallurgical Engineering Amirkabir University of TechnologyTehranIran Advanced Materials Research Center Department of Materials EngineeringNajafabad BranchIslamic Azad UniversityNajafabadIran

Magnesium(Mg) has attracted wide interest in orthopedic applications as they exhibit great biodegradability and strong biocompatibility,while corrosion is the main concern for Mg that should be addressed prior to biomedical applications. In this work, ZM31(Mg-3Zn-1Mn)/x RGO(x = 0, 0.5, 1 and 1.5 wt%) biocomposites were synthesized by semi-powder metallurgy method. The results showed that the RGO acting as an effective reinforcing filler to prevent deformation and showed better compressive strength(282.3 ± 9 MPa) and revealed enhancement in failure Strain(7.8 ± 2.1%) at 1 wt% RGO concentration compared to Mg alloy(244.5 ± 9 MPa and 7.1 ± 1.5%respectively). Moreover, fracture analysis indicated a more ductile fracture of the nanocomposites after the incorporation of RGO. Crack bridging, crack deflection and crack branching are dominant mechanisms for reinforcement of Mg-based containing RGO. Mg composites containing 0.5 wt% RGO showed a low corrosion rate(2.75 mm/year), while more incorporation of RGO resulted in an increased corrosion rate(4.38 mm/year). In addition, the degradation rate of ZM31 alloy(2.57 mg·cm-2·d-1) obviously decreased with the addition of 0.5 wt%RGO(1.84 mg·cm-2·d-1) in the SBF. Besides, continuous apatite layers were created on the composites in the SBF solution. Also, the cell culture examinations showed good cell viability and adhesion on composites with 0.5 and 1 wt% RGO, which was demonstrated by the SEM and MTT assay The alkaline phosphatase(ALP) activity of the ZM3–0.5RGO composite was considerably higher than that of ZM31matrix alloy in 24 h and 48 h, implying higher osteoblastic differentiation. The antibacterial behavior toward both bacteria(E. coli and ***) exhibited that escalating RGO concentration in Mg-matrix composites leads to further inhibition of bacteria growth. These findings suggested that ZM31–0.5RGO biocomposite could be a more promising candidate for orthopedic implants.

关键词： Mg alloys Reduced graphene oxide Mechanical properties Corrosion resistance Antibacterial activity Biocompatibility

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A microemulsion method for preparation of thiol-functionalized gold nanoparticles

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Particuology 2018年第2期16卷 33-36页

作者： somayeh Tianimoghadam Alireza Salabat Department of Chemistry Faculty of Science Lorestan University 68137-1-7133 Khorramabad Iran Department of Chemistry Faculty of Science Arak University 38156-8-8349 Arak Iran Institue of Nanosciences & Nanotechnolgy Arak University 38156-8-8349 Arak Iran

A new microemulsion method using tetraoctylammonium bromide as a cationic surfactant has been formulated to fabricate thiol-functionalized gold nanoparticles, The nanoparticles were compared with those synthesized by the multistep Brust two-phase *** nanoparticle sizes and size distributions fabricated by the two methods were characterized by UV-vis ahsorbance spectroscopy and transmittance electron microscopy. The simple microemulsion method produced the same results as those obtained by the Brust method,

关键词： Gold nanoparticles Brust method Microemulsion Thiol-functionalized gold

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Exact Solutions of Five Complex Nonlinear Schr¨odinger Equations by Semi-Inverse Variational Principle

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Communications in Theoretical Physics 2014年第9期61卷 301-307页

作者： Mohammad Najafi somayeh Arbabi Medical Biology Research Center Kermanshah University of Medical SciencesKermanshah Iran

In this paper, we establish exact solutions for five complex nonlinear Schr¨odinger equations. The semiinverse variational principle(SVP) is used to construct exact soliton solutions of five complex nonlinear Schr¨odinger equations. Many new families of exact soliton solutions of five complex nonlinear Schr¨odinger equations are successfully obtained.

关键词： two-dimensional Schr¨odinger equation three-dimensional Schr¨odinger equation unstable Schr¨odinger equation

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Dependence of Nitrogen/Argon Reaction Gas Amount on Structural,Mechanical and Optical Properties of Thin WNx Films

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Chinese Physics Letters 2017年第12期34卷 56-60页

作者： somayeh Asgary Amir Hoshang Ramezani Department of Physics West Tehran BranchIslamic Azad UniversityTehranIran

WNxfilms are deposited by reactive chemical vapor deposition at different amounts of nitrogen in gas *** data demonstrate that nitrogen amount has a strong effect on microstructure, phase formation,texture morphology, mechanical and optical properties of the WNxfilms. With increasing nitrogen a phase transition from a single WNxphase with low crystallinity structure to a well-mixed crystallized hexagonal WNxand face-centered-cubic W2N phases appears. Relatively smooth morphology at lower N2concentration changes to a really smooth morphology and then granular with coarse surface at higher N2concentration. The SEM observation clearly shows a columnar structure at lower N2concentration and a dense nanoplates one for higher nitrogen content. The hardness of WNxthin films mainly depends on the film microstructure. The absorbance peak position shifts to shorter wavelength continuously with increasing nitrogen amount and decreasing particle size.

关键词： SEM Mechanical and Optical Properties of Thin WN_x Films Dependence of Nitrogen/Argon Reaction Gas Amount on Structural

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Differences in nano-topography and tribochemistry of ZDDP tribofilms from variations in contact configuration with steel and DLC surfaces

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Friction 2022年第2期10卷 296-315页

作者： Lucija COGA somayeh AKBARI Janez KOVA Mitjan KALIN NanoSciTec GmbH Munich 80687Germany Department of Surface Engineering and Optoelectronics Jo?ef Stefan InstituteLjubljana 1000Slovenia Laboratory for Tribology and Interface Nanotechnology Faculty of Mechanical EngineeringUniversity of LjubljanaLjubljana 1000Slovenia

In this work,we evaluated the effect of the counter-body material(the same or dissimilar)and contact configuration(moving or stationary body),at similar contact tribological conditions,on the tribochemical and nanotopography characteristics of adsorbed surface *** dialkyldithiophosphate(ZDDP),the best performing anti-wear additive,was used in self-mated steel/steel and DLC/DLC contacts,which were compared with mixed steel/DLC and DLC/steel contacts in 1-h and 6-h sliding *** macroscale(tribometer)and nanoscale(atomic force microscopy)friction,thickness,topography,and chemical(attenuated total reflection-Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy)properties of the tribofilms were *** results revealed unexpectedly large differences in all the studied tribofilm parameters;this is because all the tribofilms are completely different;this includes the chemical composition,which is known to have a crucial effect on the nano-and macro-scale tribological *** results clearly demonstrate that the surface material,additives,and common contact operating parameters,that is,pressure,velocity,and temperature,crucially affect the ZDDP tribofilm as well as the position of the moving or stationary surface within the contact,and the material of the moving/stationary bodies.

关键词： dithiophosphate(ZDDP) diamond-like carbon(DLC) steel tribofilm tribochemistry nano-friction thickness topography

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Numerical Solutions of Fractional Differential Equations by Using Fractional Taylor Basis

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IEEE/CAA Journal of Automatica Sinica 2017年第1期4卷 98-106页

作者： Vidhya Saraswathy Krishnasamy somayeh Mashayekhi Mohsen Razzaghi Department of Mathematics and Statistics Mississippi State University Department of Mathematics Florida State University

In this paper, a new numerical method for solving fractional differential equations(FDEs) is presented. The method is based upon the fractional Taylor basis approximations. The operational matrix of the fractional integration for the fractional Taylor basis is introduced. This matrix is then utilized to reduce the solution of the fractional differential equations to a system of algebraic equations. Illustrative examples are included to demonstrate the validity and applicability of this technique.

关键词： Caputo derivative fractional differential equations(FEDs) fractional Taylor basis operational matrix Riemann-Liouville fractional integral operator

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Perovskites for Laser and Detector Applications

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Energy & Environmental Materials 2019年第2期2卷 146-153页

作者： Saunak Das somayeh Gholipour Michael Saliba Institute of Physical Chemistry(IPC) Friedrich Schiller University JenaHelmholtzweg 4Jena 07743Germany Leibniz Institute of Photonic Technology(IPHT) Albert-Einstein-Str.907745Jena Germany Adolphe Merkle Institute University of Fribourg CH 1700Switzerland Institute of Materials Science Technical University of DarmstadtD-64287Germany

Perovskite materials have triggered a renewed interest in photovoltaic research in the recent *** display crystal forms with 0D,1D and 2D,3D motifs,and several chemical forms,namely inorganic(titanates,rubidiates,nobiates,tantalates etc.),organic/inorganic metal halides with single to multiple cations,and even organic polymer or quantum dot-infused *** crystal type and chemical form are endowed with specific physicochemical,optical,electronic,and morphological *** unique properties render them suitable for targeted applications,namely photovoltaics,LEDs,photocatalysis/electrolysis/solar fuels/solar and Li-ion batteries,gas-sensors,ferroelectrics,capacitors,transistors and memristors,photodetectors,and lasers,for advanced quantum cryptography and outer space *** first,the crystal and material types,and physicochemical,morphological,and optoelectronic properties of perovskite materials are ***,we focus on those properties which cumulatively contribute to their application in the abovementioned ***,a comprehensive discussion about the advances in each field is ***/property/application relationships with key advances demonstrate the versatility of perovskites in modern optoelectronic technologies.

关键词： 2D perovskites hybrid perovskites micro-lasers X-ray detectors c-ray detectors

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On the monomorphism category of n-cluster tilting subcategories

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Science China Mathematics 2022年第7期65卷 1343-1362页

作者： Javad Asadollahi Rasool Hafezi somayeh Sadeghi Department of Pure Mathematics Faculty of Mathematics and StatisticsUniversity of IsfahanIsfahan 81746-73441Iran School of Mathematics and Statistics Nanjing University of Information Science&TechnologyNanjing 210044China

Let M be an n-cluster tilting subcategory of mod-Λ,whereΛis an Artin *** S(M)denote the full subcategory of S(Λ),the submodule category of Λ,consisting of all the monomorphisms in *** construct two functors from S(M)to mod-Λ,the category of finitely presented additive contravariant functors on the stable category of *** show that these functors are full,dense and objective and hence provide equivalences between the quotient categories of S(M)and mod-Λ.We also compare these two functors and show that they differ by the n-th syzygy functor,provided M is an n Z-cluster tilting *** functors can be considered as higher versions of the two functors studied by Ringel and Zhang(2014)in the case Λ=k[x]/and generalized later by Eiríksson(2017)to self-injective Artin *** applications are provided.

关键词： submodule categories n-abelian categories n-cluster tilting subcategories

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Kaempferol attenuates cognitive deficit via regulating oxidative stress and neuroinflammation in an ovariectomized rat model of sporadic dementia

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Neural Regeneration Research 2018年第10期13卷 1827-1832页

作者： somayeh Kouhestani Adele Jafari Parvin Babaei Cellular and Molecular Research Center Faculty of MedicineGuilan University of Medical Sciences Department of Physiology Faculty of MedicineGuilan University of Medical Sciences Neuroscience Research Center Guilan University of Medical Sciences

Alzheimer＇s disease（AD） is associated with oxidative stress, and ultimately results in cognitive deficit. Despite existing literature on the pathophysiology of AD, there is currently no cure for AD. The present study investigated the effects of kaempferol（Kmp） isolated from the extract of Mespilus germanica L.（medlar） leaves on cognitive impairment, hippocampal antioxidants, apoptosis, lipid peroxidation and neuro-inflammation markers in ovariectomized（OVX） rat models of sporadic AD. Kaempferol, as the main flavonoid of medlar extract has been previously known for anti-oxidative, anti-inflammatory and anti-neurotoxic effects. Thirty-two female Wistar rats were ovariectomized, and randomly divided into four groups： sham, OVX ＋ saline, OVX ＋ streptozotocin（STZ）＋ saline, OVX ＋ STZ ＋ Kmp. Animals received intracerebroventricular injection of STZ（3 mg/kg, twice with one day interval） to establish models of sporadic AD. Intraperitoneal injection of Kmp（10 mg/kg） for 21 days was performed in the OVX ＋ STZ ＋ Kmp group. Spatial learning and memory of rats were evaluated using a Morris water maze. Finally, brain homogenates were used for biochemical analysis by enzyme-linked immunosorbent assay. The results showed a significant improvement in spatial learning and memory as evidenced by shortened escape latency and searching distance in Morris water maze in the OVX ＋ STZ ＋ Kmp group compared with the OVX ＋ STZ group. Kmp also exhibited significant elevations in brain levels of antioxidant enzymes of superoxide dismutase and glutathione, while reduction in tumor necrosis factor-α and malondialdehyde. Our results demonstrate that Kmp is capable of alleviating STZ-induced memory impairment in OVX rats, probably by elevating endogenous hippocampal antioxidants of superoxide dismutase and glutathione, and reducing neuroinflammation. This study suggests that Kmp may be a potential neuroprotective agent against cognitive deficit in AD.

关键词： Alzheimer's disease oxidative stress neuroinflammation Mespilus germanica L. Kaempferol neural regeneration

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Geochemistry of platinum-group elements in the podiform chromitites and associated peridotites of the Nain ophiolites,Central Iran:Implications for geotectonic setting

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Acta Geochimica 2021年第5期40卷 752-772页

作者： Batoul Taghipour somayeh Shabani Alireza K Somarin Department of Earth Sciences Faculty of SciencesShiraz UniversityShirazIran Department of Geology Brandon UniversityBrandonMBCanada

The Nain ophiolite complex with an extent of[600 km2 is a part of the Central Iranian ophiolite,which is related to the opening and subsequent closure of the Neo-Tethys *** and serpentinized harzburgite in the Nain area host podiform chromitites that occur as three(eastern Hajhossein,western Hajhossein,and Soheil Pakuh)schlieren-type tabular and aligned massive lenses with various *** most common chromitite ore textures are massive,nodular,disseminated,and banded,reflecting crystal settling *** Cr#[Cr/(Cr+Al)]ranges from 0.43 to 0.81(average 0.63).The Mg#[Mg/(Mg+Fe2+)]varies from 0.25 to 0.78(average0.62).The Nain ophiolite and hosted chromitite are generally characterized by high Cr#,reflecting crystallization from a very hot boninite magma in a MORB *** high Cr#in the Nain chromitite also indicates a high degree of melting(15%–35%)of the depleted *** average total PGE content in the ophiolitic host rock(harzburgite and dunite)and chromite are 107 and 221 ppb,*** Nain ophiolite and chromitite have high IPGE/PPGE and negative Pt*(Pt/Pt*=0.6)anomaly,which is a characteristic of high Cr#*** U-shaped REE pattern of dunite host rock suggests the interaction of depleted mantle peridotite with boninitic *** data suggest that the Nain chromitites are related to the boninitic magma emplacement in a suprasubduction zone.

关键词： Nain chromitite Platinum group elements Ushaped REE pattern Boninitic magma Supra-subduction zone

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