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El-Sayed Y.,Ain Shams University | Ismail T.,National Institute of Laser Enhanced Science | Mostafa H.,American University in Cairo
International Conference on Transparent Optical Networks | Year: 2015

All-Optical Clock and Data Recovery (OCDR) is considered the most promising technique to increase the optical networks distance and the data rate by synchronizing and regenerating the data along the fiber cable, consequently achieving small Bit Error Rate (BER) at the receiver end. In this paper, we design and implement the OCDR using two different techniques, Self-Pulsating (SP) using Distributed Bragg Reflector laser (DBRL) and Filtering based using Fiber Brag Grating (FBG). A comparative study and measurement of the network performance for the two methods have been presented. The experimental results show clearly the increase either transmission distance or the bitrate. © 2015 IEEE. Source

Elsherbini A.A.,National Institute of Laser Enhanced Science
International journal of nanomedicine | Year: 2011

The current radiofrequency ablation technique requires invasive needle placement. On the other hand, most of the common photothermal therapeutic methods are limited by lack of accuracy of targeting. Gold and magnetic nanoparticles offer the potential to heat tumor tissue selectively at the cellular level by noninvasive interaction with laser and radiofrequency. Gold nanospheres and gold-coated magnetic nanocomposites were used for inducing hyperthermia to treat subcutaneous Ehrlich carcinoma implanted in female mice. In mice treated with gold nanospheres, tumors continued to grow but at a slow rate. In contrast, more than 50% of the tumors treated with gold-coated magnetic nanocomposites completely disappeared. This simple and noninvasive method shows great promise as a technique for selective magnetic photothermal treatment. Source

Loutfy S.A.,National Cancer Institute | Al-Ansary N.A.,National Institute of Laser Enhanced Science | Abdel-Ghani N.T.,Cairo University | Hamed A.R.,National Research Center of Egypt | And 7 more authors.
Asian Pacific Journal of Cancer Prevention | Year: 2015

Aims: To investigate effect of metallic nanoparticles, silver (AgNPs) and gold nanoparticles (AuNPs) as antitumor treatment in vitro against human breast cancer cells (MCF-7) and their associated mechanisms. This could provide new class of engineered nanoparticles with desired physicochemical properties and may present newer approaches for therapeutic modalities to breast cancer in women. Materials and Methods: A human breast cancer cell line (MCF-7) was used as a model of cells. Metallic nanoparticles were characterized using UV-visible spectra and transmission electron microscopy (TEM). Cytotoxic effects of metallic nanoparticles on MCF-7 cells were followed by colorimetric SRB cell viability assays, microscopy, and cellular uptake. Nature of cell death was further investigated by DNA analysis and flow cytometry. Results: Treatment of MCF-7 with different concentrations of 5-10nm diameter of AgNPs inhibited cell viability in a dose-dependent manner, with IC50 value of 6.28μM, whereas treatment of MCF-7 with different concentrations of 13-15nm diameter of AuNPs inhibited cell viability in a dose-dependent manner, with IC50 value of 14.48μM. Treatment of cells with a IC50 concentration of AgNPs generated progressive accumulation of cells in the S phase of the cell cycle and prevented entry into the M phase. The treatment of cells with IC50 concentrations of AuNPs similarly generated progressive accumulation of cells in sub-G1 and S phase, and inhibited the entrance of cells into the M phase of the cell cycle. DNA fragmentation, as demonstrated by electrophoresis, indicated induction of apoptosis. Conclusions: Our engineered silver nanoparticles effectively inhibit the proliferation of human breast carcinoma cell line MCF-7 in vitro at high concentration (1000 μM) through apoptotic mechanisms, and may be a beneficial agent against human carcinoma but further detailed study is still needed. Source

Saleh H.M.,Cairo University | Abdelhamid S.,National Institute of Laser Enhanced Science | Abdelhamid M.,National Institute of Laser Enhanced Science | Youssef T.,National Institute of Laser Enhanced Science | Gohar A.K.,Cairo University
Photomedicine and Laser Surgery | Year: 2014

Objective: Prior to plasmonic photothermal therapy, involving heating of gold nanoparticles (GNPs) by laser, we explored some subcellular events that may threaten the viability of rat kidney cells (RKCs) incubated with GNPs irradiated with pulsed laser. Background data: We have previously shown a decrease in the viability of RKCs, on incubation with GNPs irradiated with pulsed laser. This decrease in viability was concomitant to a reduction in GNP diameter size, and reflected the occurrence of subcellular toxic events. Methods: After incubation of RKCs with GNPs irradiated with 532 nm pulsed laser (50 mJ/pulse energy, 5 ns duration, and 10 Hz repetition rate for 1, 3, and 5 min), we studied the cell membrane integrity, the induction of apoptosis, and the occurrence of oxidative stress. We reported the changes induced on RKCs by GNPs irradiated with pulsed laser and those induced on the same cells and after the same time intervals by unirradiated GNPs; both were related to a negative control. Results: The decrease in viability of RKCs on incubation with GNPs irradiated with pulsed laser was shown to be mostly secondary to a cell membrane disruption, most probably related to the reduction in GNP diameter sizes. The oxidative stress exerted by smaller GNPs on RKCs, as well as the induction of apoptosis, seem to be tolerated by the RKCs. Conclusions: Irradiation of GNPs with pulsed laser, to elicit a plasmonic photothermal effect, reduces the GNPs' diameter. The smaller-sized GNPs may lead to lethal cell membrane disruption in healthy RKCs. © Copyright 2014, Mary Ann Liebert, Inc. 2014. Source

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