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Synthesis and Characterization of SnO2Flower-Shaped by Hydrothermal Route for Formaldehyde Sensing Properties

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Advances in Materials Physics and Chemistry 2021年第4期11卷 67-77页

作者： Abeer Alhadi Shuyi Ma Shitu Pei Tingting Yang Pengdou Yun Qianqian Zhang hamouda adam hamouda Li Wang Omer Almamoun Altayeb Alshiply Pengfei Cao Manahil H. Balal Khalid Ahmed Abbakar Key Laboratory of Atomic and Molecular Physics & Functional Materials of Gansu Province College of Physics and Electronic Engineering Northwest Normal University Lanzhou China College of Chemistry and Chemical Engineering Northwest Normal University Lanzhou China Department of Chemistry Faculty of Science University of Kordofan El Obeid Sudan Faculty of Petroleum and Hydrology Engineering West Kordofan Peace University Almugled Sudan Department of Physics Faculty of Education University of Khartoum Khartoum Sudan Physics Department Faculty of Science and Art Al Baha University Gilwah KSA Department of Mathematics and Physics Faculty of Education University of Gadarif Gadarif Sudan College of Mathematics and Statistics Northwest Normal University Lanzhou China

In this work, we’ve made SnO2 flower formed with the aid of using easy test steps, and without cost, which is the hydrothermal approach and without a template. We have used a variety of techniques to characterize SnO2 flower-shaped by (SEM, TEM, XRD, BET and XPS) instruments. Confirmatory tests carried out have proven that the surface of the tetragonal structure of SnO2 has a rough surface which makes it excellent for its gas-sensing properties. The gas detection test of SnO2 flower-shaped proved that it possesses the selectivity of formaldehyde gas (about 30), the optimum operating temperature of the sensor is 220°C, and also the sensor has a high response time and recovery time is (5 s and 22 s) to 100 ppm, respectively. Particularly, the sensor has an obvious response value (2) when exposed to 5 ppm formaldehyde. As well, the mechanism of gas-sensing was also discussed.

关键词： SnO2 Flower-Shaped Hydrothermal Method Formaldehyde Semiconductor Gas Sensor

Expression and characterization of a novel GH128 laminarinase OUC-BsLam26 harboring both hydrolyzing and transferring activities

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Food Science and Human Wellness 2024年

作者： Yueyang Dong Yongyi Quan Hong Jiang Hamed I.hamouda Zewei Lu Yimiao Chen Chengqiang Li Xiangzhao Mao State Key Laboratory of Marine Food Processing and Safety Control， College of Food Science and Engineering， Ocean University of China Qingdao Key Laboratory of Food Biotechnology Sanya Ocean Research Institute， Ocean University of China Processes Design and Development Department， Egyptian Petroleum Research Institute Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology Key Laboratory of Biological Processing of Aquatic Products，China National Light Industry

Laminarin oligosaccharides (LOSs) with a specific degree of polymerization prepared through the laminarin degradation via laminarinase present more significant nutritional functions and application values. Human intestinal bacteria are promising potential producers of novel carbohydrate-active enzymes with unique properties. Here， a novel glycoside hydrolase family 128 (GH128) laminarinase OUC-BsLam26 from the intestinal bacterium Bacteroides sp. CBA7301 was heterologously expressed and characterized. The recombinant OUC-BsLam26 with a molecular mass of 49.86 kDa exhibits highest activity (6.60 U/mg) at 45 ℃ and pH 6.0， which shows noticeable temperature and pH stability. The purified OUC-BsLam26 could degrade laminarin via an endo-type mode with the generation of laminaripentaose， laminaritetraose， laminaritriose， and laminaribiose， among them， laminaritetraose is the principal product， which accounts for 45.25% of the total products， which is significantly different from the reported GH128 laminarinases. The minimum recognition substrate of OUC-BsLam26 is laminarihexaose. Furthermore， OUC-BsLam26 also could catalyze the transglycosylation process with the production of some novel glycosides. Altogether， the intestinal bacterium Bacteroides sp. CBA7301 contains laminarinase with unique product composition and OUC-BsLam26 is a hopeful bio-catalyst with the potential to produce laminaritetraose and some novel glycosides.

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Current perspectives of nanoparticles in medical and dental biomaterials

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The Journal of Biomedical Research 2012年第3期26卷 143-151页

作者： Ibrahim Mohamed hamouda Department of Dental Biomaterials and Restorative Dentistry Faculty of Dentistry Mansoura University Mansoura Dakahleya 35516 Egypt

Nanotechnology is gaining tremendous impetus due to its capability of modulating metals into their nanosize, which drastically changes the chemical, physical and optical properties of metals. Nanoparticles have been intro- duced as materials with good potential to be extensively used in biological and medical applications. Nanoparticles are clusters of atoms in the size range of 1-100 nm. Inorganic nanoparticles and their nano-composites are applied as good antibacterial agents. Due to the outbreak of infectious diseases caused by different pathogenic bacteria and the development of antibiotic resistance, pharmaceutical companies and researchers are searching for new antibacterial agents. The metallic nanoparticles are the most promising as they show good antibacterial properties due to their large surface area to volume ratios, which draw growing interest from researchers due to increasing microbial resistance against metal ions, antibiotics and the development of resistant strains. Metallic nanoparticles can be used as effective growth inhibitors in various microorganisms and thereby are applicable to diverse medical devices. Nanotechnology discloses the use of elemental nanoparticles as active antibacterial ingredient for dental materials. In dentistry, both restorative materials and oral bacteria are believed to be responsible for restoration failure. Secondary caries is found to be the main reason to restoration failure. Secondary caries is primarily caused by invasion of plaque bacteria （acid-producing bacteria） such as Streptococcus mutans and lactobacilli in the presence of fermentable carbohydrates. To make long-lasting restorations, antibacterial materials should be made. The potential of nanoparticles to control the formation of biofilms within the oral cavity is also coming under in- creasing scrutiny. Possible uses of nanoparticles as topically applied agents within dental materials and the appli- cation of nanoparticles in the control of oral infection

关键词： nanoparticles nano-medicine nano-biomaterials nanotechnology antibacterial agent

Maxillary denture flange and occlusal discrepancies of Vertex ThermoSens in comparison with conventional heat-cured denture base materials

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The Journal of Biomedical Research 2019年第2期33卷 139-144页

作者： Hanadi A.Lamfon Ibrahim M.hamouda Maxillofacial and Oral Rehabilitation Department Umm Al-Qura University Conservative Dentistry Faculty of Dentistry Umm Al-Qura University Dental Biomaterials Faculty of Dentistry Mansoura University

This study was conducted to investigate the maxillary denture bases and occlusal discrepancies using the Vertex Thermosens in comparison with the conventional polymethyl-methacrylate materials. Twenty maxillary denture bases were prepared from the Vertex ThermoSens and a conventional heat-cured denture base materials. Acrylic maxillary second molars were arranged in their respective positions on the ridge. After curing of both types of denture bases, they were deflasked with their respective master casts. Reference points were prepared for measurements of the antero-posterior and cross-arch dimensions at the denture borders using caliper device. Furthermore, the teeth discrepancies were measured between reference points in the ligual aspect of the second maxillary molars. The recorded data was analyzed using SPSS statistical software version 20. The results showed initial shrinkage of both denture bases in the antero-posterior and cross-arch dimensions immediately after decasting. This contraction was compensated gradually during storage in water up to 2 weeks. Regarding the variable time, there was a significant difference between the tested materials. Moreover, the results revealed occlusal discrepancies and shifting of teeth inward immediately after decasting, followed by outward movement after storage in water for 2 weeks. Regarding the variables time and materials, there were significant differences. Both materials exhibited inward shrinkage in the antero-posterior and cross-arch dimensions immediately after decasting. Both denture bases showed inward shifting of teeth immediately after decasting, followed by outward movement after storage in water up to 2 weeks.

关键词： denture distortion flange discrepancy acrylic resin occlusal discrepancies denture base

p53 antibodies,metallothioneins,and oxidative stress markers in chronic ulcerative colitis with dysplasia

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World Journal of Gastroenterology 2011年第19期17卷 2417-2423页

作者： Hala E hamouda Soha S Zakaria Saber A Ismail Mahmoud A Khedr Wael W Mayah Department of Medical Biochemistry Faculty of MedicineTanta University Department of Tropical Medicine Faculty of MedicineTanta University

AIM:To investigate the role of p53 antibodies (p53Abs),metallothioneins (MTs) and oxidative stress markers in the early detection of dysplasia in chronic ulcerative colitis (UC).METHODS:The study included 30 UC patients,15 without dysplasia (group Ⅱ) and 15 with dysplasia (group Ⅲ),in addition to 15 healthy volunteers (group Ⅰ,control subjects).The enzyme-linked immunosorbent assay technique was used to measure serum p53Abs and MTs,while advanced oxidation protein products (AOPPs),and reduced glutathione (GSH) levels were measured by spectrophotometric method in all ***:In group Ⅱ and group Ⅲ compared to group Ⅰ,there were significant increases in serum levels of AOPPs (145.94 ± 29.86 μmol/L and 192.21 ± 46.71 μmol/L vs 128.95 ± 3.06 μmol/L,P 0.096).In contrast,GSH levels showed a significant decrease in both patients' groups (1.87 ± 0.02 μmol/mL and 1.37 ± 0.09 μmol/mL vs 2.49 ± 0.10 μmol/mL,P < 0.05 and P < 0.05 in groups Ⅱ and Ⅲ,respectively) compared with group Ⅰ,and the levels were significantly lower in group Ⅲ than group Ⅱ (P < 0.05).There was a positive correlation between AOPPs and both MTs (r=0.678,P < 0.001) and p53Abs (r=0.547,P < 0.001),and also between p53Abs and MTs (r=0.739,P < 0.001).There was a negative correlation between AOPPs and GSH (r =-0.385,P < 0.001),and also between GSH and both MTs (r=-0.662,P < 0.001) and p53Abs (r=-0.923,P < 0.001).CONCLUSION:Oxidative stress and oxidative cellular damage play an important role in the pathogenesis of chronic UC and the associated carci

关键词： Ulcerative colitis Advanced oxidation protein products Reduced glutathione Metallothionein

Comparative Study of Different Cryptographic Algorithms

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Journal of Information Security 2020年第3期11卷 138-148页

作者： Baha Eldin hamouda Hassan hamouda Department of Information Technology Gulf Colleges Hafar Al-Batin KSA

With the increasing interconnection of computer networks and sophistication of cyber-attacks, Cryptography is one way to make sure that confidentiality, authentication, integrity, availability, and identification of data user can be maintained as well as security and privacy of data provided to the user. Symmetric key cryptography is a part of the cryptographic technique which ensures high security and confidentiality of data transmitted through the communication channel using a common key for both encryption and decryption. In this paper I have analyzed comparative encryption algorithms in performance, three most useful algorithms: Data Encryption Standard (DES), Triple DES (3DES) also known as Triple Data Encryption Algorithm (TDEA), and Advanced Encryption Standard (AES). They have been analyzed on their ability to secure data, time taken to encrypt data and throughput the algorithm requires. The performance of different algorithms differs according to the inputs.

关键词： Cryptography DES 3DES AES Encryption Decryption Ciphertext Plaintext

Fracture resistance of posterior teeth restored with modern restorative materials

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The Journal of Biomedical Research 2011年第6期25卷 418-424页

作者： Ibrahim M. hamouda Salah H. Shehata Department of Biomaterials Mansoura University Al-Gomhoria St Mansoura 35516 Egypt Department of Conservative Dentistry Mansoura University Al-Gomhoria St Mansoura 35516 Egypt

We studied the fracture resistance of maxillary premolars restored with recent restorative materials. Fifty maxillary premolars were divided into five groups： Group 1 were unprepared teeth; Group 2 were teeth prepared without restoration; Group 3 were teeth restored with tetric ceram HB; Group 4 were teeth restored with InTen S; and Group 5 were teeth restored with Admira. The samples were tested using a universal testing machine. Peak loads at fracture were recorded. The teeth restored with Admira had the highest fracture resistance followed by those restored with InTen-S and tetric ceram HB. Prepared, unrestored teeth were the weakest group. There was a significant difference between the fracture resistance of intact teeth and the prepared, unrestored teeth. There was also a significant difference among the tested restorative materials. Teeth restored with Admira showed no significant difference when compared with the unprepared teeth. It was concluded that the teeth restored with Admira exhibited the highest fracture resistance.

关键词： fracture resistance composite resin adhesives mesio-occlusal-distal (MOD) cavities

Aggressive primary hepatic epithelioid hemangioendothelioma:a case report and literature review

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Cancer Biology & Medicine 2017年第2期14卷 187-190页

作者： Mehdi Afrit Meher Nasri Soumaya Labidi Nesrine Mejri Houda El Benna hamouda Boussen Medical Oncology Department Abderahman Mami Hospital

A new case of epithelioid hemangioendothelioma is reported to have occurred to a 67-year-old patient who consulted for rightsided chest pain. The work-up showed multiple right pulmonary lesions associated with bilateral moderate pleural effusion and left-sided pleural thickening and three hypodense nodules in the right lobe of the liver, peritoneal thickening, ascites, and multiple vertebral lytic lesions. The diagnosis of an epithelioid hemangioendothelioma was concluded through a histological examination of a computed tomography scan guided biopsy of the liver. The patient received a primary mono-chemotherapy with Adriamycin(75 mg/m^2 every three weeks) and intravenous bisphosphonates without response and general status impairment. The patient died after 16 months of follow-up.

关键词： Hemangioendothelioma epithelioid metastatic liver treatment

Rainfall patterns of Algerian steppes and the impacts on natural vegetation in the 20^th century

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Journal of Arid Land 2018年第4期10卷 561-573页

作者： Fahima BELALA Azziz HIRCHE Serge D MULLER Mahmoud TOURKI Mostefa SALAMANI Mohamed GRANDI TaharAIT hamouda Madjid BOUGHANI Laboratory of Plant Ecology Faculty of Biological SciencesUniversity of Sciences and Technology Houari BoumedieneWilaya 16000Algeria Scientific and Technical Research Center on Arid Regions Biskra 7000Algeria Institute of Evolutionary Sciences University of Montpellier-CNRSMontpellier 34095France Department of Hydraulics University of Badji MokhtarAnnaba 23000Algeria Faculty of Nature Sciences University of Saad DahlabBlida 9000Algeria Faculty of Sciences University of Yahia FaresWilaya 26000Algeria

Since 1960, the steppe regions of North Africa have been subject to an increasing desertification, including the degradation of traditional pastures. The initially dominant species （Artemisia herba-alba, Lygeum spartum and Slipa tenacissima） declined and were progressively replaced by other species （Atractylis serratuloides and Salsola vermiculata） that are more tolerant to the new conditions. It is not clear whether these changes are due to anthropogenic reasons or climatic determinism. We have carried out a statistical analysis of the climate to detect putative rainfall changes during the 20th century in the Algerian steppes based on data from 9 meteorological stations, including 2 Saharan stations （El Oued and Touggourt）, 3 pre-Saharan stations （Biskra, Laghouat and Ain Sefra） and 4 steppe stations （Djelfa, Saida, M6ch6ria and E1-Bayadh） located in the arid high plains, which represent the bioclimate diversities of the region. Previous studies suggested that significant rainfall changes for the 20th century only had records in the south of the Oran region. Most of the studies, however, looked at restricted territories over limited periods, and did not integrate the rainiest period 2004-2014. Our work is designed to integrate all the longest time series of meteorological data available for the steppe regions of Algeria. Our results confirm the spatial rainfall distribution （significant rainfall changes only recorded in the southwestern region） evidenced by previous studies, and reveal a decreasing rainfall gradient from northeastern to southwestern Algeria. Moreover, the results reveal a trend of significant decrease of rainfall in the southern Oran region, marked by two drought periods in 1980- 1985 and 1999-2003. However, with the exception of the southwestern region, rainfall overall has not declined since the beginning of the 20th century. While less marked in other regions, the drought appear to have affected all territories of the Algerian steppe. Consequent

关键词： climate arid and semi-arid regions drought rangeland degradation human impact North Africa