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Hassan Ahmed Hassan Ahmed Ismail,강병훈,김재수,이재형,최인욱,차광호,육재민,이영하 대한기생충학ㆍ열대의학회 2017 The Korean Journal of Parasitology Vol.55 No.6
IL-12 and IL-23 are closely related in structure, and have been shown to play crucial roles in regulation of immune responses. However, little is known about the regulation of these cytokines in T cells. Here, we investigated the roles of PI3K and MAPK pathways in IL-12 and IL-23 production in human Jurkat T cells in response to Toxoplasma gondii and LPS. IL-12 and IL-23 production was significantly increased in T cells after stimulation with T. gondii or LPS. T. gondii and LPS increased the phosphorylation of AKT, ERK1/2, p38 MAPK, and JNK1/2 in T cells from 10 min post-stimulation, and peaked at 30-60 min. Inhibition of the PI3K pathway reduced IL-12 and IL-23 production in T. gondii-infected cells, but increased in LPS-stimulated cells. IL-12 and IL-23 production was significantly reduced by ERK1/2 and p38 MAPK inhibitors in T. gondii- and LPS-stimulated cells, but not in cells treated with a JNK1/2 inhibitor. Collectively, IL-12 and IL-23 production was positively regulated by PI3K and JNK1/2 in T. gondii-infected Jurkat cells, but negatively regulated in LPS-stimulated cells. And ERK1/2 and p38 MAPK positively regulated IL-12 and IL-23 production in Jurkat T cells. These data indicate that T. gondii and LPS induced IL-12 and IL-23 production in Jurkat T cells through the regulation of the PI3K and MAPK pathways; however, the mechanism underlying the stimulation of IL-12 and IL-23 production by T. gondii in Jurkat T cells is different from that of LPS.
Ismail Hassan Ahmed Hassan Ahmed,차승만,김연,홍성태 대한기생충학ㆍ열대의학회 2023 The Korean Journal of Parasitology Vol.61 No.2
In several schistosomiasis-endemic countries, the prevalence has remained high in some areas owing to reinfection despite repeated mass drug administration (MDA) interventions; these areas are referred to as persistent hot spots. Identifying hotspots is critical for interrupting transmission. This study aimed to determine an effective means of identifying persistent hot spots. First, we investigated the differences between Schistosoma haematobium and Schistosoma mansoni prevalence among school-aged children (SAC) estimated by a community-based survey, for which local key informants purposively selected communities, and a randomly sampled school-based survey. A total of 6,225 individuals residing in 60 villages in 8 districts of North Kordofan, Blue Nile, or Sennar States, Sudan participated in a community-based survey in March 2018. Additionally, the data of 3,959 students attending 71 schools in the same 8 districts were extracted from a nationwide school-based survey conducted in January 2017. The community-based survey identified 3 districts wherein the prevalence of S. haematobium or S. mansoni infection among SAC was significantly higher than that determined by the randomly sampled school survey (e.g., S. haematobium in the Sennar district: 10.8% vs. 1.1%, P<0.001). At the state level, the prevalence of schistosomiasis among SAC, as determined by the community-based survey, was consistently significantly higher than that determined by the school-based survey. Purposeful selection of villages or schools based on a history of MDA, latrine coverage, open defecation, and the prevalence of bloody urine improved the ability for identifying persistent hot spots.
Curcumin Effect on MMPs and TIMPs Genes in a Breast Cancer Cell Line
Hassan, Zeinab Korany,Daghestani, Maha Hassan Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.7
Curcumin (CM) possesses anti-cancer activity against a variety of tumors. Matrix metalloproteinases (MMPs) play an important role in remodeling the extracellular matrix and their activities are regulated by tissue inhibitor of metalloproteinases (TIMPs) family. Control of MMP and TIMP activity are now of great significance. In this study, the effect of CM is investigated on metastatic MMPs and anti-metastatic TIMPs genes on MDA breast cancer cells cultured in a mixture of DMEM and Ham's F12 medium and treated with different concentrations of CM (10, 20 and $40{\mu}M$ for various lengths of time. Reverse transcription followed by quantitative real time PCR was used to detect the gene expression levels of MMPs and TIMPs in CM-treated versus untreated cases and the data were analyzed by one-way ANOVA. At high concentrations of curcumin, TIMP-1, -2, -3 and -4 genes were up-regulated after 48 hours of treatment, their over-expression being accompanied by down-regulation of MMP-2 and MMP-9 gene expression levels in a concentration- and time-dependent manner. These results suggest that curcumin plays a role in regulating cell metastasis by inhibiting MMP-2 and MMP-9 and up-regulating TIMP1 and TIMP4 gene expression in breast cancer cells.
Chitosan effects on glass matrices evaluated by biomaterial. MAS-NMR and biological investigations
Hassane Oudadesse,Eric Wers,Xuang Vuong Bui,Claire Roiland,Imane Akhiyat,Amany Mostafa,Hassan Chaair,Hicham Benhayoune,Joel Fauré,Pascal Pellen-Mussi,Bruno Bureau 한국화학공학회 2013 Korean Journal of Chemical Engineering Vol.30 No.9
Bioactive glass 46S6 and biodegradable therapeutic polymer (Chitosan: CH) have been elaborated to form 46S6-CH composite by freeze-drying process. The kinetics of chemical reactivity and bioactivity at the surface were investigated by using physicochemical techniques, particularly solid-state MAS-NMR. Immortalized cell line used to construct multicellular spheroids was employed as three-dimensional (3D) cell cultures for in vitro studies. Obtained results showed a novel structure of the composite; the chemical treatment (ultrasound, magnetic stirring, freeze drying process and lyophilization) led the bioactive glass particles to be loaded in the chitosan-based materials. 29Si and 31P MAS-NMR results showed the emergence of two new species, QSi 3(OH) and QSi 4, which are characteristic of the vitreous network dissolution in simulated body fluid (SBF). MAS-NMR also confirmed the formation of amorphous calcium phosphate (ACP) at the surface of the initial 46S6-CH. Three-dimensional (3D) cell cultures highlighted the effect of chitosan, where the cell viability reached up to 78% in 46S6-CH composite and up to 67% in 46S6. The association of (CH) and bioactive glass (BG) matrix promotes a highly significant bioactivity, demonstrating surface bone formation and satisfactory behavior in biological environment.
Wide range and stable ink-jet printed humidity sensor based on graphene and zinc oxide nanocomposite
Hassan, Gul,Bae, Jinho,Lee, Chong Hyun,Hassan, Arshad Springer-Verlag 2018 Journal of materials science Materials in electron Vol.29 No.7
<P>Nanocomposite materials are being used for different applications due to their hybrid and unique properties. In this paper, we propose a humidity sensor based on Graphene and zinc oxide nanocomposite thin film. The composite combines the advantages of both the individual materials and improves sensor performance. Addition of conductive graphene to the insulator ZnO results in fall of intrinsic impedance and also in improvement of sensitivity at low relative humidity levels. The sensor consists of silver inter-digital electrodes (IDEs) that are printed on a low cost transparent polyethyleneterephthalate (PET) substrate by DMP-3000 with dimension of 100 A mu m finger width, 50 A mu m spacing, and 500 nm thickness. To achieve a high sensitivity and wide sensing range, the active layer of composite thin film was deposited over the IDEs through spin coating to achieve a thickness of similar to 300 nm. The sensor can effective detect relative humidity in range of 0-85% RH with fast response and recovery times of 1 and 2 s respectively that are comparable to high end commercial sensors.</P>
Inkjet-printed antenna on thin PET substrate for dual band Wi-Fi communications
Hassan, A.,Ali, S.,Hassan, G.,Bae, J.,Lee, C. H. Springer Science + Business Media 2017 Microsystem Technologies Vol.23 No.8
<P>In this paper, we propose a high gain antenna operating over dual band of 900 MHz and 2.4 GHz. The proposed antenna is designed by finite element method (FEM) based Ansys high frequency structure simulator (HFSS). We use conductive ink of silver nanoparticles (AgNPs) and commercial Dimatix material inkjet printer (DMP-3000) to print the proposed antenna on 50-micron thick, transparent and flexible polyethyleneterephthalate (PET) substrate. To characterize the fabricated antenna, we use vector network analyzer (VNA) and obtain reflection coefficients of -16.4 dB at 900 MHz and -26 dB at 2.4 GHz, which accord with the HFSS simulation results. HFSS simulated results provide antenna gains as high as 16.74 and 16.24 dBi at 900 MHz and 2.4 GHz, respectively and 23.33 and 11.66 % of -10 dB fractional bandwidth at 900 MHz and 2.4 GHz, respectively. These results suggest that the proposed high gain antenna can be used for dual band Wi-Fi and wearable devices as well.</P>
Hassan, Gul,Bae, Jinho,Hassan, Arshad,Ali, Shawkat,Lee, Chong Hyun,Choi, Yohan Elsevier 2018 Composites. Part A, Applied science and manufactur Vol.107 No.-
<P><B>Abstract</B></P> <P>Strain sensors based on graphene are attracting a lot of attention for electronic applications due to its outstanding electrical and mechanical properties. In this paper, we propose a high stretchable strain sensor based on graphene flakes/ZnO composite, which is deposited on micro-random ridged type PDMS substrate. To connect between graphene flake to flake, ZnO nano particles are applied and best graphene flakes and ZnO nano particles blending ratio is 1:0.5. Using this ink, an active layer is fabricated on the micro-random ridged PDMS substrate at ambient conditions through commercialized inkjet printer DMP-3000. Especially, utilizing the micro-random ridged 1.06 mm thick PDMS substrate with surface roughness of 0.34, its stretchability is achieved up to 30%. The flexibility of the fabricated strain sensor is demonstrated down to 10 mm bending diameter. These results reveal that the proposed strain sensor has potential in diverse wearable electronic applications and diverse human motions.</P>