The Experts below are selected from a list of 165 Experts worldwide ranked by ideXlab platform
Ahmed Y. Gamal - One of the best experts on this subject based on the ideXlab platform.
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In vitro evaluation of the human gingival fibroblast/gingival mesenchymal stem cell dynamics through perforated guided Tissue Membranes: cell migration, proliferation and Membrane stiffness assay.
Journal of periodontal research, 2017Co-Authors: Ahmed Y. Gamal, N. N. Al-berry, Ahmed Abdel Aziz Hassan, Laila A. Rashed, Vincent J. IaconoAbstract:Background Migration of gingival fibroblasts/gingival mesenchymal stem cells through macro-perforated barrier Membranes may allow them to participate positively in periodontal regeneration. The optimal guided Tissue Membrane perforation diameter that could favor maximum cell migration into the defect area and at the same time act as an occlusive barrier for gingival epithelium and its associated gingival extracellular matrix component is not yet identified. Material and Methods Cultured human gingival fibroblasts/gingival mesenchymal stem cells were placed in the upper chambers of 12-well collagen-coated polytetrafluoroethylene transwells, which were manually perforated with 0.2, 0.4 and 0.7 mm sized pores. The lower chambers of the transwells received blood clot as an attraction medium. The number of cells that have migrated to the lower chambers was calculated. Proliferation of these cells was evaluated using MTT assay. Scanning electron microscopy images were obtained for the lower surfaces of the transwell Membranes. Perforated bovine collagen Membranes (Tutopatch®) were subjected to mechanical testing to determine the tensile strength and modulus of elasticity. Results Group 3 (0.7 mm) showed significantly higher values for cell migration and proliferation. All groups showed a small degree of extracellular matrix migration through Membrane perforations. Scanning electron microscopy evaluation revealed variable numbers of cells in fibrin matrices located mainly around the pore edges. There were non-significant differences between groups regarding mechanical properties. Conclusions The present study demonstrated that macro-Membrane perforations of 0.2, 0.4 and 0.7 mm are suitable pore diameters that could maintain Membrane stiffness and allow for cellular migration. However, these Membrane perforation diameters did not allow for total gingival connective Tissue isolation.
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Platelet-derived growth factor-BB release profile in gingival crevicular fluid after use of marginal periosteal pedicle graft as an autogenous guided Tissue Membrane to treat localized intrabony defects.
Journal of periodontology, 2010Co-Authors: Ahmed Y. Gamal, Ossama Sayed Ahmed El-shal, Mahmoud Mohammed El-aasara, Eman Mohammed FakhryAbstract:Background: The aim of this study is to evaluate levels of platelet-derived growth factor-BB (PDGF-BB) in gingival crevicular fluid (GCF) during the early stages of healing for sites treated by marginal periosteal pedicle (MPP) graft as an autogenous guided Tissue Membrane compared to that of the control open flap debridement (OFD).Methods: Fifteen non-smoking patients (13 males and 2 females) with severe chronic periodontitis participated in this prospective, controlled, masked trial. Each subject contributed matched pairs of 2- or 3-walled intrabony interproximal defects in premolar or molar teeth. Interproximal contralateral defects were randomly assigned to either the MPP group 1 or control OFD group 2. GCF samples were collected at 1, 3, 7, 14, and 30 days after surgery. PDGF-BB in the GCF samples was measured using a human PDGF-BB enzyme-linked immunosorbent assay kit.Results: In both MPP and OFD, PDGF-BB concentrations peaked in the samples obtained during the early postoperative days (days 2 and 3...
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A novel marginal periosteal pedicle graft as an autogenous guided Tissue Membrane for the treatment of intrabony periodontal defects.
Journal of the International Academy of Periodontology, 2008Co-Authors: Ahmed Y. Gamal, Jason M. MailhotAbstract:OBJECTIVE The aim of the present study was to clinically examine the effects of a novel marginal periosteal pedicle graft (MPP) as a guided Tissue Membrane for treating proximal intrabony defects in comparison to a an open flap debridement. MATERIAL AND METHODS Fifteen patients with severe chronic periodontitis and no systemic diseases participated in this prospective, controlled clinical trial. Each subject contributed matched pairs of interproximal two- or three-walled intrabony defects. Baseline clinical examination included plaque index (PlI), gingival index (GI), bleeding on probing (BOP), probing depth (PD) and clinical attachment level (CAL) of selected sites and were performed two weeks following completion of cause-related therapy. Radiographic measurements were also recorded to ascertain the radiographic depth of the defect. Each pair of periodontal defects were randomly assigned into the experimental group G1, marginal periosteal pedicle graft (MPP) guided Tissue Membrane or the control open flap debridement group, G2. In the MMP, partial thickness flaps were elevated at the vestibular surface of the tooth adjacent to the interproximal defect to harvest a 4 mm marginal pedicle periosteal graft. Exposed root surfaces were root planed and the remaining bony walls of the selected defect were degranulated prior to the periosteal pedicle barrier Membrane being rotated to cover the intrabony defect. Sites representing the control group were treated with only open flap debridement. Clinical and radiographic parameters were recorded at 3, 6 and 9 months after surgery for treatment outcome evaluation. RESULTS Baseline data showed no differences in any of the investigated parameters, suggesting parameters were balanced between the two groups. Both experimental and control groups showed significant improvements in all of the soft and hard Tissue parameters when compared to baseline (p < 0.001). At nine months, the experimental MPP group showed significant improvement in PD reduction, CAL gain and intrabony defect reduction when compared to the control (p < 0.01). In the MPP group, the mean reduction in PD was 3.8 mm, mean CAL gain was 3.4 mm and mean reduction in intrabony defect was 2.2 mm. In sites treated with open flap DEBRIDEMENT, the mean PD reduction was 2.5 mm, CAL gain was 2.0 mm and mean reduction in intrabony defect was 0.6 mm. CONCLUSION Within the limits of this study, it can be concluded that the placement of a marginal periosteal pedicle graft as a barrier Membrane significantly improved clinical and radiographic parameters of deep intrabony defects and proved superior to OPEN FLAP DEBRIDEMENT alone.
Csaba Biro - One of the best experts on this subject based on the ideXlab platform.
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mitoq loaded chitosan hyaluronan composite Membranes for wound healing
Materials, 2018Co-Authors: Tamer M. Tamer, M S Mohyeldin, Ahmed M Omer, Karol Svik, Rastislav Jurcik, ľubomir Ondruska, Katarína Valachová, Mohamed A Hassan, Maurice N Collins, Csaba BiroAbstract:Two self-associating biopolymers, namely chitosan (Ch) and a high-molar-mass hyaluronan (HA), were used to prepare Membranes with the aim to protect and to enhance the healing of injured skin. A mitochondrially-targeted antioxidant—MitoQ—was incorporated into the mixture of biopolymers prior to their self-association. These three-component Membranes were evaluated in detail utilising surface roughness measurements, contact angle measurements, hemocompatibility, and thrombogenicity analyses. Furthermore, in vivo application of Ch/HA/MitoQ Membranes was assessed on injured rabbit and rat skin utilizing histological methods. The results showed that the prepared thrombogenic Ch/HA/MitoQ Membranes had higher roughness, which allowed for greater surface area for Tissue Membrane interaction during the healing processes, and lower cytotoxicity levels than controls. MitoQ-loaded composite Membranes displayed superior healing properties in these animal models compared to control Membranes.
Bin Zhang - One of the best experts on this subject based on the ideXlab platform.
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Self-Floating Carbonized Tissue Membrane Derived from Commercial Facial Tissue for Highly Efficient Solar Steam Generation
ACS Sustainable Chemistry & Engineering, 2019Co-Authors: Yaxi Chen, Zhigang Chen, Yi Huang, Bin ZhangAbstract:Solar steam generation holds great promise for practically utilizing solar energy in seawater desalination and sewage purification on a large scale. It has been proven that local heating of superficial water can maximize the energy efficiency for steam generation. Accordingly, photothermal materials are required to float on the water during this process. However, the fabrication of a photothermal material with a self-floating ability, low cost, and easy-preparation for solar steam generation is highly challenging. Herein, a self-floating carbonized Tissue Membrane for high-efficiency solar steam generation is prepared via the carbonization of commercial facial Tissue. The low-cost and scalable carbonized Tissue Membrane can float on water without any assistance and can effectively generate water steam at the rate of 4.45 kg m–2 h–1 with a photothermal conversion efficiency of as high as 95% under 3-sun illumination. The self-floating ability, high solar steam generation performance, and low cost cause the...
Akio Kishida - One of the best experts on this subject based on the ideXlab platform.
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Preparation of a collagen/polymer hybrid gel for Tissue Membranes. Part II: In vitro and in vivo biological properties of the collagen gels
Acta biomaterialia, 2009Co-Authors: Kwangwoo Nam, Tsuyoshi Kimura, Seiichi Funamoto, Akio KishidaAbstract:Abstract The aim of the present study was to evaluate the biological properties of a collagen–phospholipid polymer hybrid gel (MiC30 gel) designed for use as a Tissue Membrane. The following four types of collagen gels were synthesized and tested in vitro and in vivo: physically cross-linked collagen gel (Uc gel), N -(3-dimethylaminopropyl)- N ′-ethylcarbodiimide (EDC)/ N -hydroxysuccinimide-cross-linked collagen gel (EN gel), MiC30 gel and glutaraldehyde-cross-linked collagen gel (G gel). The cell adhesivity and proliferation rate were observed to be lowest for the MiC30 gel and highest for the Uc gel, indicating that the phospholipid–polymer-covered surface of the collagen gel interacted weakly with cells. The collagen gel was implanted into rats subcutaneously and was observed 1, 2 and 8 weeks after implantation. The Uc gel and G gel were degraded and induced an inflammatory response. Granulation was not observed for 8 weeks after implantation and the formation of foreign body giant cells was observed around both the Uc and G gels. On the other hand, cell infiltration and degradation were not observed in the case of the EN and MiC30 gels. The formation of foreign body giant cells was suppressed and the healing process was accelerated. The MiC30 gel is suitable for use as a biomaterial that is stable in vivo because it suppresses the foreign body response and accelerates the healing process.
Qi Meng - One of the best experts on this subject based on the ideXlab platform.
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A hybrid approach based on differential evolution and Tissue Membrane systems for solving constrained manufacturing parameter optimization problems
Applied Soft Computing, 2013Co-Authors: Gexiang Zhang, Jixiang Cheng, Marian Gheorghe, Qi MengAbstract:This paper presents a hybrid approach based on appropriately combining Differential Evolution algorithms and Tissue P Systems (DETPS for short), used for solving a class of constrained manufacturing parameter optimization problems. DETPS uses a network Membrane structure, evolution and communication rules like in a Tissue P system to specify five widely used DE variants respectively put inside five cells of the Tissue Membrane system. Each DE variant independently evolves in a cell according to its own evolutionary mechanism and its parameters are dynamically adjusted in the process of evolution. DETPS applies the channels connecting the five cells of the Tissue Membrane system to implement communication in the process of evolution. Twenty-one benchmark problems taken from the specialized literature related to constrained manufacturing parameter optimization are used to test the DETPS performance. Experimental results show that DETPS is superior or competitive to twenty-two optimization algorithms recently reported in the literature.
