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Open Journal of Applied Sciences 2014年第3期4卷 96-102页

作者： Hanan Ali Maram T. H. Abou Kana mohamed atta khedr Department of Laser Sciences and Interactions National Institute of Laser Enhanced Sciences University of Cairo Giza Egypt

Samarium doped Yttrium aluminum garnet (YAG) nanopowders with different concentration (0.5%, 1%, 2%, 3%, 5% and 8% mol) were prepared by simple and low cost co-precipitation method. We found that the precursor begins converting to pure YAG at relatively low temperature around 900°C, and no intermediate phases were detected. The powders annealed at 900°C and 1000°C in air with average particle size around ≈30 nm were characterized by means of X-ray diffraction (XRD) analysis and infrared (IR) spectroscopy. The photoluminescent measurements showed that the reddish-orange (RO) emission transition 4G5/2:6H7/2 is more prominent. In addition, the optimum concentration of doped Sm ions that lead to maximum intensity was reported. Also, fluorescence efficiencies as pumping power dependence for different Sm3+ ions concentrations were explored.

关键词： Sm3+ YAG Nanopowders Concentration Dependence Optical Properties Ceramics

Gain Coefficient Calculation for Short Wave Laser Emission from Sodium like Co

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Optics and Photonics Journal 2013年第8期3卷 369-378页

作者： Wessameldin S. Abdelaziz Mai E. Ahmed mohamed atta khedr Tharwat M. El-Sherbini Environmental Affairs Agency Cairo Egypt Laboratory of Lasers and New Materials Cairo University Cairo Egypt National Institute of Laser Enhanced Sciences Cairo University Cairo Egypt

Level structure, oscillator strengths, transition probabilities and radiative life times are evaluated for 1s2 2s2 2p63l, 4l, 5l (l = 0, 1, 2, 3, 4) states in sodium like Co16+. The calculations are carried out using COWAN code. The calculations made were compared with other results in literature where a good agreement is found. We also report on some unpublished energy values and oscillator strengths. Our results are used in the calculation of reduced population of 21 fine structure levels over a wide rang of electron density values (1018 to 1020) at various electron plasma temperature. For those transitions with positive population inversion factor, the gain coefficients are evaluated and plotted against the electron density.

关键词： Level Structure Oscillator Strengths Transition Probabilities and Radiative Life Times Sodium like Co16+

Digital Watermarking Scheme for Securing Textual Database Using Histogram Shifting Model

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Computers, Materials & Continua 2022年第6期71卷 5253-5270页

作者： Khalid A.El Drandaly Walid khedr Islam S.mohamed Ayman mohamed Mostafa Faculty of Computers and Informatics Zagazig UniversityZagazig44519Egypt College of Computer and Information Sciences Jouf UniversitySakaka72314Saudi Arabia

Information security is one of the most important methods of protecting the confidentiality and privacy of internet *** greater the volume of data,the more the need to increase the security methods for protecting data from *** task can be challenging for researchers in terms of managing enormous data and maintaining their safety and *** of digital content is a major issue in maintaining the privacy and secrecy of *** this end,digital watermarking is based on the concept of information security through the insertion and detection of an embedded watermark in an efficient *** methodologies in the research on digital watermarking result in data distortion after embedding the *** scenario can reduce the efficiency of detecting watermarks as well as violate data *** study adapts a robust reversible histogram shifting(HS)technique for textual data in relational ***,the study presents a digital watermarking scheme intended for document copyright protection and proof of *** major advantage of the proposed watermarking scheme is that it can protect digital data and preserve data *** the best of our knowledge,this research methodology is promising for use in the HS expansion model for watermarking data on nonnumeric *** addition,the results showed that despite exposing the database to an insertion attacks at 50%and 75%of the watermark,the proposed algorithm can recovermore than half of the embedded watermark in all addition and alteration attacks *** a result,the watermark information can be retained and restored completely.

关键词： Information security digital watermarking information hiding histogram shifting technique

Synthesis, Structural Characterization, and Antimicrobial Activities of Mn（II）, Co（II）, Ni（II）, Cu（ll） and Zn（II） Complexes of Triazole-based Azodyes

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Chinese Journal of Chemistry 2011年第6期29卷 1124-1132页

作者： khedr, Abdalla M. Gaber, mohamed Abd EI-Zaher, Eman H. Chemistry Department Faculty of Science Tanta University Tanta Egypt Botany Department Faculty of Science Tanta University Tanta Egypt

The synthesis and characterization of new transition metal complexes of Mn（ll）, Co（II）, Ni（II）, Cu（II） and Zn（II） with 3-（2-hydroxynaph-l-ylazo）-1,2,4-triazole （HL1） and 3-（2-hydroxy-3-carboxynaph-l-ylazo）-1,2,4-triazole （HL2） have been carried out. Their structures were confirmed by elemental analyses, thermal analyses, spectral and magnetic data. The IR and 1H NMR spectra indicated that HL1 and HL2 coordinated to the metal ions as bidentate monobasic ligands via the hydroxyl O and azo N atoms. The UV-Vis, ESR spectra and magnetic moment data revealed the formation of octahedral complexes [MnL1（AcO）（H2O）3] （1）, [CoL1（AcO）（HzO）3]·H2O （2）, [MnL2- （AcO）（H20）3] （6） and [CoL2（AcO）（H2O）3] （7）, [NiL1（AcO）（H2O）] （3）,[ZnLI（AcO）（HzO）]·H2O （5）, [NiL2- （AcO）（H2O）] （8）, [ZnL2（AcO）（H2O）]·H2O （10） have tetrahedral geometry, whereas [CuLI（AcO）（H2O）2] （4） and [CuL2（AcO）（H2O）2]·5H2O （9） have square pyramidal geometry.. The mass spectra of the complexes under EI-con- ditions showed the highest peaks corresponding to their molecular weights, based on the atomic weights of 55Mn, 59Co, 58Ni, 63Cu and 64Zn isotopes; besides, other peaks containing other isotopes distribution of the metal. Kinetic and thermodynamic parameters of the thermal decomposition stages were computed from the thermal data using Coats-Redfern method. HL2 and complexes 6--10 were found to have moderate antimicrobial activities against Staphylococcus＇ aureus （gram positive）, Escherichia coli （gram negative） and Salmonella sp bacteria, and antifungal activity against Fusarium oxysporum, Aspergillus niger and Candida albicans. Also, in most cases, metallation increased the activity compared with the free ligand.

关键词： analytical and inorganic chemistry triazole azodyes metal(II) chelates antimicrobial activities

Can miRNA712＿3p be a promising biomarker for early diagnosis of toxoplasmosis?

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Asian Pacific Journal of Tropical Medicine 2018年第12期11卷 688-692页

作者： Nermine Mogahed Fawzy Hussein Mogahed Safaa Ibrahim khedr Rasha Abdelmawla Ghazala Inas mohamed Masoud Medical Parasitology Department Faculty of Medicine Alexandria University Medical Biochemistry Department Faculty of Medicine Alexandria University Pharmaceutical Chemistry Faculty of Pharmacy and Drug Manufacturing Pharos University in Alexandria

Objective: To assess the role of miRNA712_3p as a specific biomarker in early detection of toxoplasmosis in plasma of mice acutely infected with Toxoplasma gondii. Methods: Real-time PCR was used to measure the level of miRNA712_3p in plasma of infected mice. Immunecompetent and immune-suppressed mice were examined, three and five days post-infection. Results: Results revealed significant up-regulation of plasma miRNA712_3p in both immunecompetent and immune-compromised groups in comparison to the control non-infected group. Additionally, an increase in the level of miRNA712_3p was noticed correspondently in the parasite density detected in liver impression smears. Conclusions: miRNA712_3p can be used as a novel biomarker for the detection of Toxoplasma gondii infection in both immunecompetent and immune-compromised host.

关键词： Toxoplasma gondii microRNAs miRNA7123p Biomarker Real-time PCR

Upper Footprint Dependent Nipple Position to Avoid High-Riding Nipple after Reduction Mammoplasty

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Modern Plastic Surgery 2022年第3期13卷 42-49页

作者： Wael H. Mahmoud Wesam I. Homouda mohamed H. Elghazaly mohamed M. khedr Department of Plastic and Reconstructive Surgery Faculty of Medicine Tanta University Tanta Egypt Plastic Surgery Department Benha Teaching Hospital Benha Egypt

Introduction: High-riding nipple following reduction mammoplasty is a challenging problem for the plastic surgeons. To avoid such problem, many methods have been described for marking the correct nipple position but still controversial. We aimed in this study to present our experience in preventing excessive nipple elevation after reduction mammoplasty by using the upper footprint to set the new nipple position. Material and Methods: From March 2019 to March 2022, 25 female patients at a mean age of 38.3 years were included in this prospective study. They underwent reduction mammoplasty with inverted T scar and a combination of inferior pedicle and Würinger’s septum techniques. Resection weights, pre- and postoperative anthropometric measures were recorded. All patients were photographed at the follow-up visits and evaluated for complications if any, the nipple-areola complex (NAC) sensation, and subjective patient satisfaction using “The Breast Evaluation Questionnaire”. Results: The mean preoperative midclavicular point to nipple distance was 37.40 and 37.18 cm for the right and left breasts, respectively. The mean resection weight was 1270 and 1242 g from the right and left sides, respectively. None of our patients experienced NAC necrosis, while 2 breasts had minor wound dehiscence treated conservatively. After a mean follow-up period of 12 months, the NAC descended by an average of 1.40 cm, the distance from the IMF to nipple had an average increase of 2.24 cm, and all of patients were satisfied with the esthetic outcomes and convinced with their breast shape. Conclusion: The upper footprint dependent nipple position seems to have a real role in preventing high-riding nipple after breast reduction in hypertrophic and gigantomastic breasts. Moreover, it can be applied easily and allow for more satisfying outcomes than other methods for setting the new nipple position.

关键词： High-Riding Nipple Breast Footprint Reduction Mammoplasty

一些含三氮杂茂偶氮染料O,N供体的Zr(Ⅱ)配合物的合成、表征和抗微生物活性(英文)

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无机化学学报 2014年第5期30卷 1201-1211页

作者： Supposed by Tanta Univemity. Chemistry Department Faculty of Science Tanta University

合成了9种3-(2-羟基萘基-1-偶氮)-1,2,4-三氮唑(HL1),3-(2,4-二羟苯基-1-偶氮)-1,2,4-三氮唑(HL2),3-(2-羟基-3-羧基萘基-1-偶氮)-1,2,4-三氮唑(HL3),3-(2-羟基-5-溴苯基-1-偶氮)-1,2,4-三氮唑(HL4)和3-(2-羟基-5-甲基苯基-1-偶氮)-1,2,4-1,2,4-三氮唑(HL5)的Zr(Ⅱ)配合物并用元素分析,摩尔电导,磁矩,IR,UV-Vis,1H-NMR以及热分析(TGA和DTA)对其进行了表征。结果表明HL1-HL5以二齿一元配体方式通过偶氮的氮原子和羟基基团的氧原子与Zr(Ⅱ)离子配位生成单核配合物。用4种革兰氏阴性菌,即大肠杆菌(Escherichia coli),粘质沙雷氏菌(Serratia marcescens),阴沟肠杆菌(Enterobacter cloacae)和普通变形杆菌(Proteus vulgaris),以及2种真菌,即白色念珠菌(Candida albicans)和黑曲霉菌(Aspergillus niger)对配体及其配合物的生物学活性进行了研究。最小抑菌浓度(MICs)用纸上杯碟琼脂扩散法测定,结果表明在大多数情况下,金属化的配合物的抗微生物活性与自由配体相比有所增强。

关键词：配位方式生物学活性锆配合物三氮唑偶氮染料光谱表征热分析

Adaptive Resource Management for a Vague Environment Using Cognitive Radio

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Adaptive Resource Management for a Vague Environment Using C...

Predictors for Metachronous Metastases in Early Breast Cancer: A Single Institution Study

2010 3rd IEEE International Conference on Computer Science and Information Technology—ICCSIT 2010

作者： mohamed khedr Hazem Shatila Jeffrey H. Reed Arab Academy for Science and Technology Electronics and Communication Dept. Egypt Bradley Department of Electrical and Computer Engineering Wireless Virginia Tech. Virginia Polytechnic Institute and State University Virginia USA 24061

Adapting resource management, for vague environments, in wireless communication proved to be a measure point of research recently. In this paper we present a system that is capable of adapting some important resources （type of modulation, code rate and number of subcarriers） for blurred channel conditions. The system in this work is mainly designed for WiMAX, which proved to be one of the prominent technologies in providing Broadband Wireless Access （BWA） in metropolitan areas with a simpler installation and lower cost than the wired alternatives. The approach depends on using cognitive radio for decision making which uses fuzzy logic for reasoning. The cognitive engine controls the type of modulation, code rate and number of subcarriers in order to maintain a good system throughput without wasting available bandwidth. Fuzzy logic reasoning in the cognitive engine was chosen because it is well suited for situations of uncertainty, incompleteness and heterogeneity information, in the case of fast changing radio environments. The results showed that new combinations of modulation type, code rate and number of subcarriers should be considered in WiMAX since in most cases it outperforms the standard in error probability and spectral efficiency, especially in a fast changing radio environment.

关键词： WiMAX cognitive radio fuzzy logic Fuzzy C-Mean Clustering (FCM).

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Advances in Breast Cancer Research 2021年第3期10卷 87-99页

作者： Haytham Mahmoud Awad Fayed mohamed Ali Abdalla Billel Galal Mostafa Abouelnagah Gehan A. khedr Surgical Oncology Department Alexandria Faculty of Medicine Alexandria University Alexandria Egypt Clinical Oncology Department Alexandria Faculty of Medicine Alexandria University Alexandria Egypt

Background: Breast cancer (BC) is considered the most common women cancer worldwide. The main clinicopathological prognostic factors are tumor size, lymph node status and estrogen/progesterone (ER/PR) receptor status. In addition, some factors are both prognostic and predictive as ER/PR receptors and HER2/neu overexpression. Axillary lymph node status is the most important prognostic factor for breast cancer. Node negative breast cancer patients had the best 5-year overall survival (OS) of 82.8% compared to 73%, 45.7%, and 28.4% for patients with 1 - 3, 4 - 12, and ≥13 positive nodes, respectively. The aim of this study was to determine the association between different clinicopathological features and development of metastasis in a group of Egyptian women with early breast cancer, also, to assess patients’ Relapse-free survival (DFS) and OS and their correlation with different clinicopathological features. Patients and Methods: We retrospectively reviewed the files of breast cancer patients who were treated and <

关键词： Breast Cancer Metastasis Relapse Free Survival Overall Survival

Numerical Study of Transient Temperature Distribution in Passively Q-Switched Yb:YAG Solid-State Laser

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Optics and Photonics Journal 2014年第3期4卷 46-53页

作者： Jala M. El-Azab Hamed M. Kandel mohamed A. khedr Hatem M. El-Ghandoor National Institute of Laser Enhanced Sciences Cairo University Cairo Egypt Physics Department Faculty of Science Ain Shams University Cairo Egypt

In this work, the thermal characterization of continuously pumped passively Q-switched laser is quantitatively represented. The system under investigation is end-pumped Yb:YAG passively Q-switched by Cr4+:YAG as saturable absorber. The rate equations describing the dynamics of laser action are numerically solved simultaneously with the temperature conductivity heat equation to depict the transient temperature distribution. The study has been performed in the cylindrical coordinates to characterize the temperature distribution in the axial and radial directions. The thermal transient time in both directions as well as the thermal focal length are calculated. The temporal behavior of the temperature distribution has been illustrated in a 3-dimensional diagram.

关键词： Q-Switched Laser Temperature Distribution Thermal Lensing