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      • KCI등재후보

        Effect of Silicon Dioxide and Magnesium Oxide on the Printability, Degradability, Mechanical Strength and Bioactivity of 3D Printed Poly (Lactic Acid)-Tricalcium Phosphate Composite Scaffolds

        Harb Samarah V.,Kolanthai Elayaraja,Backes Eduardo H.,Beatrice Cesar A. G.,Pinto Leonardo A.,Nunes Ana Carolina C.,Selistre-de-Araújo Heloisa S.,Costa Lidiane C.,Seal Sudipta,Pessan Luiz Antonio 한국조직공학과 재생의학회 2024 조직공학과 재생의학 Vol.21 No.2

        Background: Poly (lactic acid) (PLA) is a biodegradable polyester that has been exploited for a variety of biomedical applications, including tissue engineering. The incorporation of β-tricalcium phosphate (TCP) into PLA has imparted bioactivity to the polymeric matrix. Methods: We have modified a 90%PLA-10%TCP composite with SiO2 and MgO (1, 5 and 10 wt%), separately, to further enhance the material bioactivity. Filaments were prepared by extrusion, and scaffolds were fabricated using 3D printing technology associated with fused filament fabrication. Results: The PLA-TCP-SiO2 composites presented similar structural, thermal, and rheological properties to control PLA and PLA-TCP. In contrast, the PLA-TCP-MgO composites displayed absence of crystallinity, lower polymeric molecular weight, accelerated degradation ratio, and decreased viscosity within the 3D printing shear rate range. SiO2 and MgO particles were homogeneously dispersed within the PLA and their incorporation increased the roughness and protein adsorption of the scaffold, compared to a PLA-TCP scaffold. This favorable surface modification promoted cell proliferation, suggesting that SiO2 and MgO may have potential for enhancing the bio-integration of scaffolds in tissue engineering applications. However, high loads of MgO accelerated the polymeric degradation, leading to an acid environment that imparted the composite biocompatibility. The presence of SiO2 stimulated mesenchymal stem cells differentiation towards osteoblast; enhancing extracellular matrix mineralization, alkaline phosphatase (ALP) activity, and bone-related genes expression. Conclusion: The PLA-10%TCP-10%SiO2 composite presented the most promising results, especially for bone tissue regeneration, due to its intense osteogenic behavior. PLA-10%TCP-10%SiO2 could be used as an alternative implant for bone tissue engineering application. Background: Poly (lactic acid) (PLA) is a biodegradable polyester that has been exploited for a variety of biomedical applications, including tissue engineering. The incorporation of β-tricalcium phosphate (TCP) into PLA has imparted bioactivity to the polymeric matrix. Methods: We have modified a 90%PLA-10%TCP composite with SiO2 and MgO (1, 5 and 10 wt%), separately, to further enhance the material bioactivity. Filaments were prepared by extrusion, and scaffolds were fabricated using 3D printing technology associated with fused filament fabrication. Results: The PLA-TCP-SiO2 composites presented similar structural, thermal, and rheological properties to control PLA and PLA-TCP. In contrast, the PLA-TCP-MgO composites displayed absence of crystallinity, lower polymeric molecular weight, accelerated degradation ratio, and decreased viscosity within the 3D printing shear rate range. SiO2 and MgO particles were homogeneously dispersed within the PLA and their incorporation increased the roughness and protein adsorption of the scaffold, compared to a PLA-TCP scaffold. This favorable surface modification promoted cell proliferation, suggesting that SiO2 and MgO may have potential for enhancing the bio-integration of scaffolds in tissue engineering applications. However, high loads of MgO accelerated the polymeric degradation, leading to an acid environment that imparted the composite biocompatibility. The presence of SiO2 stimulated mesenchymal stem cells differentiation towards osteoblast; enhancing extracellular matrix mineralization, alkaline phosphatase (ALP) activity, and bone-related genes expression. Conclusion: The PLA-10%TCP-10%SiO2 composite presented the most promising results, especially for bone tissue regeneration, due to its intense osteogenic behavior. PLA-10%TCP-10%SiO2 could be used as an alternative implant for bone tissue engineering application.

      • Influence of HAPS and GEO Satellite under SANDU Layering and Gas Attenuations

        Harb, Kamal International Journal of Computer ScienceNetwork S 2021 International journal of computer science and netw Vol.21 No.12

        Satellite communication for high altitude platform stations (HAPS) and geostationary orbit (GEO) systems suffers from sand and dust (SANDU) storms in desert and arid regions. The focus of this paper is to propose common relations between HAPS and GEO for the atmospheric impairments affecting the satellite communication networks operating above Ku-band crossing the propagation path. A double phase three-dimensional relationship for HAPS and GEO systems is then presented. The comparison model present the analysis of atmospheric attenuation with specific focus on sand and dust based on particular size, visibility, adding gas effects for different frequency, and propagation angle to provide systems' operations with a predicted vision of satellite parameters' values. Thus, the proposed system provides wide range of selecting applicable parameters, under different weather conditions, in order to achieve better SNR for satellite communication.

      • SCIEKCI등재

        Effect of Triiodobenzoic Acid on Broomrape (Orobanche ramosa) Infection and Development in Tomato Plants

        Harb, Amal M.,Hameed, Khalid M.,Shibli, Rida A. The Korean Society of Plant Pathology 2004 Plant Pathology Journal Vol.20 No.2

        Branched broomrape (Orobanche ramosa) is a holo-parasitic flowering plant that attaches to the root of its host, green plant, by means of a specialized structure known as haustorium. Following successful contact and penetration on susceptible plant root, complex tissue of Orobanche cells is formed which is known as the tubercle. Newly formed tubercles contain high activity ofindole-3-acetic acid (IAA). Triiodobenzoic acid (TIBA), as an inhibitor of IAA polar transport, was utilized to investigate the supply and requirement of auxin to the developing O. ramosa on tomato plant. There was no significant reduction in the incidence of O. ramosa per pot of different TIBA treatments. However, infection severity in terms of the number of O. ramosa shoots that emerged per plant and number of attachments per plant root system were significantly reduced by 60 % and 45 % on TIBA treated plants, respectively. Histo-logical studies revealed conspicuous delay in the initiation of xylem vessel differentiation inside tubercles of the TIBA treated tomato plants. Also, differentiated vessels showed thinner secondary wall deposition, and improper alignment within bundles inside those tubercles. They were wider and shorter in diameter in comparison to those of untreated plants. These findings were attri-buted to the short supply of IAA required for normal development, and to the xylem vessel differentiation of O. ramosa tubercles on infected tomato. Hence, this parasitic flowering plant seems to depend upon its host in its requirements for IAA, in a source to sink relation-ship.

      • KCI등재

        Prevalence and Clinical Significance of Urinary Tract Infection among Neonates Presenting with Unexplained Hyperbilirubinemia in Lebanon: A Retrospective Study

        Harb Alya,Yassine Viviane,Ghssein Ghassan,Salami Ali,Fakih Hadi 대한감염학회 2023 Infection and Chemotherapy Vol.55 No.2

        Background: Neonatal jaundice is commonly seen in term and preterm newly born babies. It could be either physiologic or secondary to multiple underlying pathologies like urinary tract infection (UTI). Our main objective was to confirm the relationship between neonatal jaundice without apparent cause like hemolysis and the presence of UTI. Materials and Methods: We, retrospectively over a period extended from 2017 to 2020, included 496 babies admitted for elevated indirect hyperbilirubinemia for whom demographic, clinical, laboratory, and therapeutic data were collected through a detailed questionnaire. Results: Our study included 496 neonates and showed a prevalence of UTI in 8.9% of neonates. The two most common microorganisms in urine culture were Escherichia coli (65.9%) and Klebsiella pneumoniae (25.0%). A multivariate logistic analysis showed that UTI was associated with male neonates (odds ratio [OR] = 2.366, 95% confidence interval [CI]: 1.173 – 4.774; P = 0.016), history of prenatal UTI (OR = 5.378, 95% CI: 2.369 – 12.209; P <0.001), poor feeding (OR = 3.687, 95% CI: 1.570 – 8.661; P = 0.003), and positive urine culture in catheter (OR = 2.704, 95% CI: 1.255 – 5.826; P = 0.011). The mean length of stay was higher in patients with positive UTI (Median = 216 hours) compared to patients with negative UTI (Median = 48 hours) (P <0.001).

      • Distinction between HAPS and LEO Satellite Communications under Dust and Sand Storms Levels and other Attenuations

        Harb, Kamal International Journal of Computer ScienceNetwork S 2022 International journal of computer science and netw Vol.22 No.3

        Satellite communication for high altitude platform stations (HAPS) and low earth orbit (LEO) systems suffer from dust and sand (DU&SA) storms in the desert regions such as Saudi Arabia. These attenuations have a distorting effect on signal fidelity at high frequency of operations. This results signal to noise ratio (SNR) to dramatically decreasing and leads to wireless transmission error. The main focus in this paper is to propose common relations between HAPS and LEO for the atmospheric impairments affecting the satellite communication networks operating above Ku-band crossing the propagation path. A double phase three dimensional relationship for HAPS and LEO systems is then presented. The comparison model present the analysis of atmospheric attenuation with specific focus on sand and dust based on particular size, visibility, adding gaseous effects for different frequency, and propagation angle to provide system operations with a predicted vision of satellite parameters' values. Skillful decision and control system (SD&CS) is proposed to control applied parameters that lead to improve satellite network performance and to get the ultimate receiving wireless signal under bad weather condition.

      • SCIESCOPUSKCI등재

        Cinnamonitriles in Heterocycles Synthesis:Reaction of $\alpha,\beta$-Unsaturate Nitriles with Thioglycolic Acid

        Ali Harb, Abd Elfattah The Pharmaceutical Society of Korea 1991 Archives of Pharmacal Research Vol.14 No.3

        7H-thiazolo-[3,2-a]-pyridines as potential antimicrobial agents were prepared by reaction of $\alpha,\beta$-unsaturated nitriles and thioglycolic acid.

      • SCIESCOPUSKCI등재

        Synthesis of Newer Antipyrinyl-phenothiazine, Antipyrinyl-acridine and Sulpha Derivatives of Expected Biological Activity

        Ali Harb, Abd Elfattah The Pharmaceutical Society of Korea 1991 Archives of Pharmacal Research Vol.14 No.3

        As potential antibacterial agents, several antipyrine derivatives were synthesized from 4-formylantipyrine and antibacterial activities of the synthesized compounds were also examined.

      • SCIESCOPUSKCI등재

        Synthesis of Some Heterocycles of Potential Biological Activity

        Ali-Harb, Abd-Elfattah,Mostafa, Fatma-H.,Metwally, Saoud-A. The Pharmaceutical Society of Korea 1990 Archives of Pharmacal Research Vol.13 No.2

        A convenient method for the preparation of imidazobenzimidazole 3, imidazoimidazole 5, imidazotriazole 6 and pyrano [2, 3-c] oxazole 7 derivatives is described. This depends on interaction of 2-methyl-4-arylidene-2-oxazolin-5-ones 1 with o-diamines, thiosemicarbazide and/or ethylcyanoacetate. The effect of alcoholic potassium cyanide on axazolinone 1 was studied. Antibacterial activity of the obtained products was studied.

      • KCI등재

        Effect of Triiodobenzoic Acid on Broomrape (Orobanche ramosa) Infection and Development in Tomato Plants

        Amal M. Harb,Khalid M.Hameed,Rida A. Shibli 한국식물병리학회 2004 Plant Pathology Journal Vol.20 No.2

        Branched broomrape (Orobanche ramosa) is a holoparasitic flowering plant that attaches to the root of its host, green plant, by means of a specialized structure known as haustorium. Following successful contact and penetration on susceptible plant root, complex tissue of Orobanche cells is formed which is known as the tubercle. Newly formed tubercles contain high activity of indole-3-acetic acid (IAA). Triiodobenzoic acid (TIBA), as an inhibitor of IAA polar transport, was utilized to investigate the supply and requirement of auxin to the developing O. ramosa on tomato plant. There was no significant reduction in the incidence of O. ramosa per pot of different TIBA treatments. However, infection severity in terms of the number of O. ramosa shoots that emerged per plant and number of attachments per plant root system were significantly reduced by 60% and 45% on TIBA treated plants, respectively. Histological studies revealed conspicuous delay in the initiation of xylem vessel differentiation inside tubercles of the TIBA treated tomato plants. Also, differentiated vessels showed thinner secondary wall deposition, and improper alignment within bundles inside those tubercles. They were wider and shorter in diameter in comparison to those of untreated plants. These findings were attributed to the short supply of IAA required for normal development, and to the xylem vessel differentiation of O. ramosa tubercles on infected tomato. Hence, this parasitic flowering plant seems to depend upon its host in its requirements for IAA, in a source to sink relationship.

      • SCIESCOPUSKCI등재

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