Adhesive properties to materials used in unit care by Staphylococcus aureus strains incubated in seawater microcosms

Karima Bekir,Emira Noumi,Nabil Ben Salem Abid,Amina Bakhrouf 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.4

Four strains of Staphylococcus aureus were incubated for eight months in seawater microcosms and then tested for their ability to form a biofilm on different surfaces. Our results showed that the stressed strain became safranin and increased their capacity for producing biofilm on polystyrene microplates or glass wells. These bacteria were able to form a biofilm on the surfaces tested and the cell density was the highest on the stainless steel surface followed by polystyrene and the polyethylene surfaces. These properties allow these bacteria to survive, proliferate and persist even after treatment with antibacterial agents.

Elaboration and Characterization of TiO2 and Study of the In uence of The Number of Thin Films on the Methylene Blue Adsorption Rate

Karima Madoui,Aicha Medjahed,Melia Hamici,Abdi Djamila,Mokhtar Boudissa 한국물리학회 2018 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.72 No.10

Thin films of titanium oxide (TiO2) deposited on glass substrates were fabricated by using the sol-gel route. The realization of these thin layers was made using the dip-coating technique with a solution of titanium isopropoxyde as a precursor. The samples prepared with different numbers of deposited layers were annealed at 400 ◦ C for 2 hours. The main purposes of this work were investigations of both the effect of the number of thin TiO2 layers on the crystal structure of the anatase form first and, their ability to adsorb the solution of methylene blue in order to make colored filters from a photocatalytic process. The deposited titanium-oxide layers were characterized by using various techniques: namely, X-ray diffraction (XRD), Raman spectroscopy, atomic force microscopy (AFM) and UV-Visible spectrometry. The result obtained by using the XRD technique showed the appearance of an anatase phase, as was confirmed by using Raman spectroscopy. The AFM surface analysis allowed the surface topography to be characterized and the surface roughness to be measured, which increased with increasing number of layers. The UV-Visible spectra showed that the TiO2 films had a good transmittance varying from 65% to 95% according to the number of layers. The gap energy varied as a function of the number of deposited layers. The as deposited TiO2 layers were tested as a photocatalyst towards the adsorption of methylene blue dye. The results obtained during this study showed that the adsorption capacity varied according to the number of deposited thin layers and the exposing duration to ultraviolet (UV) light. The maximum absorption rate of the dye was obtained for the two-layer sample. Seventy-two hours of irradiation allowed the adsorption intensity of the dye to be maximized for two-layer films.

PERIODICITY AND POSITIVITY IN NEUTRAL NONLINEAR LEVIN-NOHEL INTEGRO DIFFERENTIAL EQUATIONS

( Karima Bessioud ),( Abdelouaheb Ardjouni ),( Ahcene Djoudi ) 호남수학회 2020 호남수학학술지 Vol.42 No.4

Our paper deals with the following neutral nonlinear Levin-Nohel integro-differential with variable delay By using Krasnoselskii’s fixed point theorem we obtain the existence of periodic and positive periodic solutions and by contraction mapping principle we obtain the existence of a unique periodic solution. An example is given to illustrate this work.

Spot Diagnosis Using Pulse Wave Doppler Interrogation of the Abdominal Aorta

Karima Addetia,Judith Therrien 한국심초음파학회 2012 Journal of Cardiovascular Imaging (J Cardiovasc Im Vol.20 No.2

Influence of material composition on buckling response of FG plates using a simple plate integral model

Karima Bakhti,Mohamed Sekkal,E.A. Adda Bedia,Abdelouahed Tounsi 국제구조공학회 2020 Smart Structures and Systems, An International Jou Vol.25 No.4

In this study, a simple two-dimensional shear deformation model is employed for buckling analysis of functionally graded (FG) plates. The proposed theory has a kinematic with integral terms which considers the influence of shear deformation without using "shear correction factors". The impact of varying material properties and volume fraction of the constituent on buckling response of the FG plate is examined and discussed. The benefit of this theory over other contributions is that a number of variables is reduced. The basic equations that consider the influence of transverse shear stresses are derived from the principle of virtual displacements. The analytical solutions are obtained utilizing the "Navier method". The accuracy of the proposed theory is proved by comparisons with the different solutions found in the literature.

In vitro antioxidant activity and phytochemical analysis of Teucrium pseudo-Scorodonia Desf. Collected from Algeria

Karima Belarbi,Fawzia Atik-Bekkara,Imad Abdelhamid El Haci,Ilhem Bensaid,Fawzia Beddou,Chahrazed Bekhechi 경희대학교 융합한의과학연구소 2017 Oriental Pharmacy and Experimental Medicine Vol.17 No.2

Teucrium pseudo-Scorodonia Desf., is one of many Mediterranean plants widely used in Algerian folk medicine for their medicinal properties. This study represents the first antioxidant investigation of Teucrium pseudo-Scorodonia with different analytical methods. Total phenolic, flavonoid, and condensed tannin contents were determined using spectrophotometric techniques. In vitro antioxidant and radical scavenging profiling was determined through total antioxidant capacity (TAC), DPPH radical-scavenging, ferric reducing antioxidant power (FRAP), and β-carotene bleaching assays. Leaf extracts exhibited high total phenolics (266.36 ± 0.14 mg GAE/g DW), flavonoids (161.23 ± 0.18 mg CE/g DW) and condensed tannins (5.00 ± 0.08 mg CE/g DW) contents. The greatest antioxidant activity was founding in the butanolic fraction of leaves (IC50.DPPH = 0.05 ± 0.00 mg/ml) followed by crude methanolic extract and ethyl acetate fraction. These values were to some extent high in comparison to the positive control (0.07 ± 0.01 mg/ml). The same tendency was observed with ferric reducing power. A strong correlation of IC50 values of antioxidant assays with total phenolics and total flavonoids content of T. pseudo-Scorodonia was exhibited in this study. Thin layer chromatographic (TLC) screening using DPPH radical, AlCl3 and FeCl3 as detection reagents led to the identification of potent antioxidant compounds: methylated flavonoids or hydroxyflavonols. These results indicate that flavonoids and phenolics can be the major contributors to the antioxidant activity observed for the T. pseudo-Scorodonia leaf extracts. Further study is necessary for isolation and characterization of the active antioxidants, which may serve as a potential source of natural antioxidants.

Semantic Interoperability Framework for IAAS Resources in Multi-Cloud Environment

Benhssayen, Karima,Ettalbi, Ahmed International Journal of Computer ScienceNetwork S 2021 International journal of computer science and netw Vol.21 No.2

Cloud computing has proven its efficiency, especially after the increasing number of cloud services offered by a wide range of cloud providers, from different domains. Despite, these cloud services are mostly heterogeneous. Consequently, and due to the rising interest of cloud consumers to adhere to a multi-cloud environment instead of being locked-in to one cloud provider, the need for semantically interconnecting different cloud services from different cloud providers is a crucial and important task to ensure. In addition, considerable research efforts proposed interoperability solutions leading to different representation models of cloud services. In this work, we present our solution to overcome this limitation, precisely in the IAAS service model. This solution is a framework permitting the semantic interoperability of different IAAS resources in a multi-cloud environment, in order to assist cloud consumers to retrieve the cloud resource that meets specific requirements.

Stem Cell Oriented Exosomes Regulate Cell Proliferation in Hepatoma Carcinoma

Gul Karima,신규순,정재민,최동호,황경균,홍종욱 한국생물공학회 2023 Biotechnology and Bioprocess Engineering Vol.28 No.2

Reprogrammed hepatic stem cells can generate a variety of extracellular vesicular particles including exosomes with similar therapeutic potential. However, their functional application in cancer therapy is restricted due to a poor understanding of their physical properties, antiproliferative effects, and the underlying mechanism. Here, we explore reprogrammed stem cells that can release vesicular particles with physical properties of exosomes that can exert anti-proliferative effects by regulating cell proliferationrelated genes. We obtain vesicular particles with properties of exosomes expressing CD81 and CD63 with the size distribution peak observed at 155 nm. We analyze that as compared to non-treated conditions, vesicular particles have reduced cell proliferation of Hep G2 by 93.6% after 72 h. Furthermore, we also identify that B-cell lymphoma 2 has been reduced by 89.64% and activation of caspase- 3 has occurred in treated conditions via the mitochondrial pathway. Therefore, our results may highlight the potential of exosomes from hepatic stem cells to play a vital role in treating liver pathologies.

The urban data deluge: challenges for smart urban planning in the third data revolution

Kourtit Karima,Elmlund Peter,Nijkamp Peter 서울시립대학교 도시과학연구원 2020 도시과학국제저널 Vol.24 No.4

Effective urban planning is increasingly affected and governed by the current information society. This paper argues that the so-called third data revolution creates unprecedented challenges for sustainable city policy in the digital age. Three types of data revolutions are distinguished in this paper. The nowadays popular notion of smart cities may be helpful to enhance the cognitive quality of urban policy-making, but leads also to new issues on complex data handling in the modern age of social media and digital information systems. The various issues at stake are outlined in this paper, while this study is concluded with a sketch of the contours of a so-called smart city policy fly-wheel, so as to demonstrate that the urban fabric – also in a smart city context – is always work in progress, with a view to the achievement of sustainable development goals.

고율 특성 리튬 유황 전지용 스펀지 형태의 유황-아세틸렌블랙 복합구조체

니마카리마(Neema Cyril Karima),안욱(Wook Ahn) 한국전지학회 2021 한국전지학회지 Vol.1 No.1

본 연구에서는 간단한 솔루션 기반 합성 방법으로 나노 입자 크기를 갖는 유황-아세틸렌블랙 복합체를 합성하고, 다중 기공을 갖는 스펀지 형태의 전극 복합체를 제조함으로서 유황의 담지능력을 향상시키는 연구를 수행하였다. 이는 전기전도도와 리튬폴리설파이드 화합물이 음극으로 확산하는 것을 방지하는 방법으로 사이클 내구성과 높은 에너지밀도를 실현하였다. In this study, a facile solution-based synthesis method is used to synthesize the nano-sized sulfur-acetylene black composite for Li-S battery. The sponge structured acetylene black improves the sulfur infiltration ability in the composite by creating multiple pores. The composite prevents shuttle mechanism by blocking the diffusion of polysulfide to the anode electrode, leading to the long cycle life with reliable rate capability and high energy density of Li-S battery.