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Some New Applications of S-metric Spaces by Weakly Compatible Pairs with a Limit Property
J. Mojaradi Afra,M. Sabbaghan 한국수학교육학회 2021 純粹 및 應用數學 Vol.28 No.1
In this note we use a generalization of coincidence point(a property which was defined by [1] in symmetric spaces) to prove common fixed point theorem on S-metric spaces for weakly compatible maps. Also the results are used to achieve the solution of an integral equation and the bounded solution of a functional equation in dynamic programming.
High Prevalence of AmpC β-Lactamases in Clinical Isolates of Escherichia coli in Ilam, Iran
Abbas Maleki,Afra Khosravi,Sobhan Ghafourian,Iraj Pakzad,Shiva Hosseini,Rashid Ramazanzadeh,Nourkhoda Sadeghifard 질병관리본부 2015 Osong Public Health and Research Persptectives Vol.6 No.3
Objectives: Widespread use of β-lactam antibiotics could cause resistance to this group of antibiotics in pathogenic bacteria through the production of the enzyme β-lactamases. The aimof this study is to determine themolecular detection of AmpC β-lactamases among clinical Escherichia coli isolated from Ilam hospitals in Ilam, Iran. Methods: One hundred and twelve clinical isolates of E. coli were collected from hospitalized patients and were identified by biochemical tests. They were evaluated for extended spectrum beta-lactamases (ESBLs) production, and the positive strains were subjected to AmpC enzymes; for detection of AmpC cluster genes, multiplex polymerase chain reaction was applied. Results: The analysis showed 62.5% of isolates were ESBLs positive and that five strains revealed the AmpC cluster genes. This is the first report of FOXM cluster genes in E. coli in Iran. Conclusion: Based on our results, the prevalence of AmpC β-lactamases is increasing in Iran, which caused failure in antibiotic therapy. So, the current study recommended the revision of antibiotic policy in Iranian hospitals.
Yalda Chehrehsaz,Kaveh Hajizadeh,Afra Hadjizadeh,Lida Moradi,Sara Mahshid 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.6
Despite many advantages of titanium, such as proper mechanical properties, biocompatibility and corrosion resistance, ithas two main weaknesses; low tensile strength compared to other metallic biomaterials, and inadequate osseointegrationowing to its bioinert spontaneous surface oxide layer. Grain refinement using Equal Channel Angular Pressing (ECAP) hasbeen preferred as a desirable method to enhance low tensile strength. In addition, osseointegration could be improved byelectrochemical oxidation (anodization), resulting in titania nanotubes formation on titanium surface. The latter has beenextensively studied on commercially pure titanium (CP-Ti), and the formed nanotubes have been well characterized. However,a thorough observation on anodic nanotubes of ECAP-processed coarse-grained pure titanium (CG-Ti) is missing. In thisresearch, we aimed to investigate the surface characteristics and cytotoxicity of anodic TiO2nanotubes on ECAP-processedCP-Ti substrate compared to that of CG-Ti. The results generally showed superior use of nanotubes anodized on ECAP-edCP-Ti substrates over that of coarse-grained ones. We acquired ultrafine-grained titanium (UFG-Ti) by ECAP, and synthesizedanodic nanotube arrays on both UFG-Ti and CG-Ti at different times and voltages. We compared the resulted nanotubes’morphologies, physicochemical and biological properties, in which cell culture on anodic TiO2nanotubes of ECAP-edCP-Ti has been performed for the first time by this research. FESEM results showed relatively lower diameter and longernanotubes for UFG-Ti samples rather than CG-Ti ones. Nanotubes of both substrates were amorphous, and CG-Ti nanotubeswere more hydrophilic than UFG-Ti nanotubes. Enhanced cell viability and proliferation were achieved on ECAP-ed CP-Tianodic TiO2nanotubes.
Ozan Karaman,Seyfi Kelebek,Emine Afra Demirci,Fatma Ibis,Murat Ulu,Utku Kursat Ercan 한국조직공학과 재생의학회 2018 조직공학과 재생의학 Vol.15 No.1
The aim of this study was to investigate the synergistic effect of cold atmospheric plasma (CAP) treatment and RGD peptide coating for enhancing cellular attachment and proliferation over titanium (Ti) surfaces. The surface structure of CAP-treated and RGD peptide-coated Ti discs were characterized by contact angle goniometer and atomic force microscopy. The effect of such surface modification on human bone marrow derived mesenchymal stem cells (hMSCs) adhesion and proliferation was assessed by cell proliferation and DNA content assays. Besides, hMSCs’ adhesion and morphology on surface modified Ti discs were observed via fluorescent and scanning electron microscopy. RGD peptide coating following CAP treatment significantly enhanced cellular adhesion and proliferation among untreated, CAP-treated and RGD peptide-coated Ti discs. The treatment of Ti surfaces with CAP may contribute to improved RGD peptide coating, which enables increased cellular integrations with the Ti surfaces.
Fatemeh Kashani‑Asadi‑Jafari,Ahmadreza Parhizgar,Afra Hadjizadeh 한국섬유공학회 2023 Fibers and polymers Vol.24 No.2
There are different methods for producing core–shell nanofibers, one of which is the emulsion electrospinning method. Thestability of the emulsion during electrospinning is one of the most critical factors in the quality of the fibers. In this study, amagnetic-field-assisted emulsion electrospinning system was designed, built, and tested to keep the emulsion stable withoutadditives or sonication. Polycaprolactone (PCL) 10 wt. % in dichloromethane (DCM) for the shell and gelatin 2.5 wt. % inwater for the core was used. Scanning electron microscope (SEM) image of samples with different weight ratios of componentsboth with and without using the magnetic-field-assisted emulsion electrospinning system at different rotational speedswas investigated. Transition electron microscope (TEM) images of the sample with a ratio of 1/10 (gel/PCL) at differentrotational speeds were studied. The fibers were finally analyzed by Fourier transform infrared (FTIR) and tensile strengthmachine. According to the results, there was no change in the bonds in the materials after electrospinning. The designedsystem improved the fiber texture and reduced its structural problems significantly. By increasing the rotation speed of themagnet from 700 to 900 rpm, an improvement in fiber morphology and uniformity in diameter was observed. The compositionof gelatin/PCL with a ratio of 1/10 was selected as the optimal condition. The spun nanofibers in these conditionshad a uniform structure without the bead, and the presence of both polymers uniformly in the fibers was shown. Finally,the magnetic-field-assisted emulsion electrospinning system successfully held the emulsion stable during electrospinningwithout additives.
Akinci, Sema,Silay, Kamile,Ulas, Arife,Guney, Tekin,Hacibekiroglu, Tuba,Basturk, Abdulkadir,Akinci, Muhammed Bulent,Alkan, Afra,Dilek, Imdat Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.24
Purpose: Neutrophil-to-lymphocyte ratio (NLR) was evaluated as a potential prognostic factor in patients with myelodysplastic syndrome (MDS). Materials and Methods: Between December 2009 and April 2014, 14 female (35%) and 26 male (65%) MDS patients who were followed up in our hematology clinic were included in the study for NLR during diagnosis. Division was into two groups according to the NLR, and the correlation with mortality was evaluated. The prognostic significance of NLR regarding treatment outcome was also evaluated with adjustment for known confounding risk factors. Results: The mortality rate of the patient group was 55%, and median survival was 18 months. There was no significant correlation between mortality and NLR at a median value of 1.8 (p=0.75). Thrombocytopenia was observed to increase mortality (p=0.027), and there was a significant correlation between mortality and pancytopenia (p=0.017). Conclusions: This first study of NLR and mortality did not show any significant correlation. In centres with limited access to genetic evaluation for the presence of pancytopenia and/or thrombocytopenia at the time of diagnosis, a platelet level less than $50{\times}10^9/l$ may be poor prognostic markers in MDS patients.