检索结果-南通市图书馆

sol-gel synthesis,properties and protein loading/delivery capacity of hollow bioactive glass nanospheres with large hollow cavity and mesoporous s.ell

在线全文

学校读者我要写书评

暂无评论

Frontiers of Materials science 2022年第3期16卷 145-157页

作者： ahmed el-FIQI Glass Research Department National Research CentreCairo 12622Egypt

Hollow nanospheres exhibit unique properties and find a wide interest in several potential applications such as drug ***,novel hollow bioactive glass nanospheres(HBGn)with large hollow cavity and large mesopores in their outer s.ells were synthesized by a simple and facile one-pot ultrasound assisted sol-gel method using PEG as the core ***,the produced HBGn exhibited large hollow cavity with ~43 nm in diameter and mesoporous s.ell of ~37 nm in thickness and 7 nm pore size along with nanosphere size around 117 *** confirmed the presence of si and Ca elements at the surface of the HBGn outer ***,HBGn showed high protein loading capacity(~570 mg of Cyto c per 1 g of HBGn)in addition to controlled protein release over 5 *** also demonstrated a good in vitro capability of releasing calcium(Ca^(2+):170 ppm)and silicate(siO_(4)^(4-):78 ppm)ions in an aqueous medium over 2 weeks under physiological-like *** in vitro growth of bone-like hydroxyapatite nanocrystals was exhibited by HBGn during the soaking in sBF.A possible underlying mechanism involving the formation of spherical aggregates(coils)of PEG was proposed for the formation process of HBGn.

关键词： bioactive glass hollow nanosphere hollow cavity mesoporous s.ell soft-template ultrasound assisted sol-gel synthesis therapeutic protein delivery

Nanosecond pulse and dual-wavelength Q-switched 1.5 μm fiber laser using MAX phase Cr2TiAlC2 saturable absorber

在线全文

学校读者我要写书评

暂无评论

Optoelectronics Letters 2025年第1期21卷 7-12页

作者： ahmed shakir AL-HITI Hiba HAssAN Department of electrical Engineering Faculty of Engineering University of Anbar Department of Laser and Optoelectronics Engineering University of Technology-Iraq

We demonstrated a new type of MAX phase material, chromium titanium aluminum carbide（Cr2TiAlC2） polymer film, to generate a passively Q-switched erbium-doped fiber laser（EDFL）. The film thickness was measured to be around 45 μm, which was fabricated using the embedding method with polyvinyl alcohol（PVA） polymer as hoster. The saturable absorber（sA） film demonstrates a dual-wavelength passively Q-switched EDFL which operates at 1 531 nm and 1 560.19 nm, respectively. The Q-switching pulse duration could be varied from 2.46 μs to 770 ns, while the repetition rate varied from 92.76 kHz to 106.6 kHz with an increasing input pumping range from 154 mW to 300 mW. The maximum output power and pulse energy of 15.05 mW and 141.18 nJ were obtained at the maximum input power of 300 mW, respectively.

关键词： saturable absorbers

LEO satellite clock analysis and prediction for positioning applications

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Geo-spatial Information science 2022年第1期25卷 14-33页

作者： Kan Wang ahmed el-Mowafy school of Earth and Planetary sciences Curtin UniversityPerthAustralia

The positioning service aided by low Earth orbit(LEO)mega-cons.ellations has become a hot topic in recent *** achieve precise positioning,accuracy of the LEO clocks is important for single-receiver *** bridge the gap between the applicable time of the clock products and the time of positioning,the precise LEO clocks need to be predicted over a certain period depending on the sampling interval of the clock *** study discusses the prediction errors for periods from 10 s to 1 h for two typical LEO clock types,*** ultra-stable oscillator(UsO)and the oven-controlled crystal oscillator(OCXO).The prediction is based on GNss-determined precise clock estimates,where the clock stability is related to the GNss estimation errors,the behaviors of the oscillators themselves,the systematic effects related to the environment and the relativistic effects,and the stability of the time *** on real data analysis,LEO clocks of the two different types are simulated under different conditions,and a prediction model considering the systematic effects is *** to a simple polynomial fitting model usually applied,the proposed model can significantly reduce the prediction errors,*** about 40%-70%in simulations and about 5%-30%for real data containing different miss-modeled *** both clock types,short-term prediction of 1 min would result in a root mean square error(RMsE)of a few centimeters when using a very stable time *** RMsE amounts to about 0.1 m,when a typical real-time time reference of the national center for space studies(CNEs)real-time clocks was *** long-term prediction of 1 h,the RMsE could range from below 1 m to a few meters for the UsOs,depending on the complexity of the miss-modeled *** OCXOs,the 1 h prediction could lead to larger errors with an RMsE of about 10 m.

关键词： LEO clock prediction UsO OCXO relativistic effects

Magnetoresistive properties of Ni-doped La_(0.7)sr_(0.3)MnO_3 manganites

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2016年第7期35卷 551-558页

作者： ahmed Mohamed ahmed Abd el-Moez ahmed Mohamed Medhat Abdelrady Abdellateef Hassan ahmed Abd el-Ghanny Physics Department Faculty of ScienceSohag University

Lao.7sr0.3Mnl_xNixO3 （x = 0, 0.025, 0.050 and 0.075） ceramics were prepared by the conventional solid-state reaction method. The partial substitution of Mn by Ni2＋ leads to a decrease in cell volume as well as a structural transition from the rhombohedral to the orthorhombic structure. Ni2＋ doping increases the electrical resistivity, decreases the semiconductor-metal transition temperature （Tms） and relatively enhances the room temperature magnetoresistance （MR）, especially in x = 0.025 and around Tins. With respect to conduction mechanism, the small polaron hopping （sPH） and the variable range hopping （VRH） models were used to ex- amine conduction in the semiconducting region.

关键词： Manganites X-ray diffraction structure electrical resistivity Magnetoresistance

Hyperspectral imaging and remote trace detection of cis-1,3,4,6-tetranitrooctahydroimidazo-[4,5 d]imidazole(BCHMX)compared with traditional explosives using laser induced fluorescence

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2021年第5期17卷 1609-1616页

作者： Hany s.Ayoub Ashraf F.el-sherif ahmed elbeih Department of Physics Faculty of ScienceCairo UniversityEgypt Laser Photonics Research Center Engineering Physics DepartmentMilitary Technical CollegeCairoEgypt Explosives Department Military Technical CollegeKobry ElkobbahCairoEgypt

cis-1,3,4,6-Tetranitrooctahydroimidazo-[4,5 d]imidazole(BCHMX)is an advanced energetic compound that expected to spread worldwide in the near ***,no approved remote detection methods were reported in current literature for this material,we performed hyper-spectral imaging and laser induced fluorescence(LIF)to a BCHMX sample under low laser fluence for determining the optimum laser wavelength used in any future BCHMX-LIF based remote detection *** this purpose,an experimental setup consisted of a sun spectrum lamp and hyper-spectral camera was built to illuminate and image white powder samples of BCHMX in comparison with the traditional explosives,HMX(1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane),RDX(1,3,5-trinitro-1,3,5-triazacyclohexane),PETN(2,2-Bis[(nitroxy)methyl]propane-1,3-diyldinitrate).The imaging reveals strong BCHMX sample absorption contrast among other samples at wavelength ranging from 400 to 410 *** light source was replaced by a 405 nm laser diode illuminator,a strong BCHMX sample LIF at the spectral range from 425 to 700 nm was observed under low laser fluence condition of 0.1 mJ/cm^(2).Finally,we demonstrated successfully the ability of the 405 nm LIF and the hyperspectral imaging technique to detect finger print traces of BCHMX on white cellulose fabric from a distance of 15 m and a detection limit of 1 mg/cm^(2).

关键词： Hyperspectral imaging Remote trace detection BCHMX Laser induced fluorescence

Biological silicon nanoparticles improve Phaseolus vulgaris L. yield and minimize its contaminant contents on a heavy metals-contaminated saline soil

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental sciences 2021年第8期33卷 1-14页

作者： Mohamed T.el-saadony el-sayed M.Desoky ahmed M.saad Rania s.M.Eid Eman selem ahmed s.elrys Department of Agricultural Microbiology Faculty of AgricultureZagazig UniversityZagazig 44511Egypt Botany Department Faculty of AgricultureZagazig UniversityZagazig 44511Egypt Biochemistry Department Faculty of AgricultureZagazig UniversityZagazig 44511Egypt Agricultural Botany Department Faculty of AgricultureBenha University13736Egypt Botany and Microbiology Department Faculty of ScienceZagazig University44511Egypt soil science Department Faculty of AgricultureZagazig University44511ZagazigEgypt

The synthesis of biological silicon nano-particles(Bio-si-NPs)is an eco-friendly and lowcost *** is no study focusing on the effect of Bio-si-NPs on the plants grown on saline soil contaminated with heavy *** this study,an attempt was made to synthesis Bio-si-NPs using potassium silica florid substrate,and the identified Aspergillus tubingensis AM11 isolate that separated from distribution systems of the potable water.A twoyear field trial was conducted to compare the protective effects of Bio-si-NPs(2.5 and 5.0 mmol/L)and potassium silicate(10 mmol/L)as a foliar spray on the antioxidant defense system,physio-biochemical components,and the contaminants contents of Phaseolus vulgaris *** on saline soil contaminated with heavy *** findings showed that all treatments of Bio-si-NPs and potassium silicate significantly improved plant growth and production,chlorophylls,carotenoids,transpiration rate,net photosynthetic rate,stomatal conductance,membrane stability index,relative water content,free proline,total soluble sugars,N,P,K,Ca2+,K+/Na+,and the activities of peroxidase,catalase,ascorbic peroxidase and superoxide oxide *** of Bio-si-NPs and potassium silicate significantly decreased electrolyte leakage,malondialdehyde,H2 O2,O2·-,Na+,Pb,Cd,and Ni in leaves and pods of Phaseolus vulgaris *** to ***-si-NPs were more effective compared to potassium *** of Bio-si-NPs at the rate of 5 mmol/L was the recommended treatment to enhance the performance and reduce heavy metals content on plants grown on contaminated saline soils.

关键词： Bean silicon Nano-silicon Aspergillus tubingensis AM11 salinity Heavy metals

Hepatoprotective Effect of Camel Thorn Polyphenols in Concanavalin A-Induced Hepatitis in Mice

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Integrative Medicine 2024年第12期30卷 1090-1100页

作者： Nageh ahmed el-Mahdy Thanaa ahmed el-Masry ahmed Mahmoud el-Tarahony .Fatemah AAlherz Enass Youssef Osman Department of Pharmacology and Toxicology Faculty of PharmacyTanta UniversityTanta 31527Egypt Department of Pharmaceutical sciences College of PharmacyPrincess Nourah Bint Abdulrahman UniversityP.O.Box 84428Riyadh 11671Saudi Arabia

Objective:To explore the prophylactic and therapeutic effects of Alhagi maurorum ethanolic extract(AME)in concanavalin A(Con A)-induced hepatitis(CIH)as well as possible underlying ***:Polyphenols in AME were characterized using high performance liquid chromatography(HPLC).swiss albino mice were divided into 4 *** group received intravenous phosphate-buffered saline(PBs);Con A group received 40 mg/kg intravenous Con *** group administered 300 mg/(kg·d)AME orally for 5 days before Con A *** group received intravenous Con A then administered300 mg/kg AME at 30 min and 3 h after Con A *** 24 h of Con A injection,hepatic injury,oxidative stress,and inflammatory mediators were *** examination and markers of apoptosis,inflammation,and CD4^(+)cell infiltration were also ***:HPLC analysis revealed that AME contains abundant polyphenols with pharmacological constituents,such as.ellagic acid,gallic acid,ferulic acid,methylgallate,and *** alleviated Con A-induced hepatic injury,as manifested by a significant reduction in alanine aminotransferase,aspartate aminotransferase and alkaline phosphatase(Ps revealed by a significant reduction in oxidative stress markers(nitric oxide and malondialdehyde)and restored glutathione(Pels of proinflammatory cytokines(tumor necrosis factor-α,interferon-γ,and interleukin-6)and c-Jun N-terminal kinase(JNK)activity were reduced(Pstopathological examination of liver tissue showed that AME significantly ameliorated necrotic and inflammatory lesions induced by Con A(Pssion of nuclear factor kappa B,pro-apoptotic protein(Bax),caspase-3,and CD4^(+)T cell hepatic infiltration(Pssion of anti-apoptotic protein Bcl-2 was increased(Psions:AME has hepatoprotective and ameliorative effects in CIH mice

关键词： concanavalin A-induced hepatitis Alhagi maurorum ethanolic extract hepatoprotective effect

Impact Assessment and Mitigation Techniques for High Penetration Levels of Renewable Energy sources in Distribution Networks:Voltage-control Perspective

在线全文

学校读者我要写书评

暂无评论

Journal of Modern Power systems and Clean Energy 2022年第2期10卷 450-458页

作者： ahmed s.A.Awad Dave Turcotte Tarek H.M.el-Fouly Natural Resources Canada Can-metENERGYVarennesCanadaon leave from the Electrical Power and Machines DepartmentFaculty of EngineeringAin Shams UniversityCairo 11566Egyp Natural Resources Canada CanmetENERGYVarennesCanada Advanced Power and Energy Center Khalifa UniversityAbu DhabiUnited Arab Emirates

The integration of renewable distributed generation(RDG)into distribution networks is promising and increasing ***,high penetration levels of distributed generation(DG)are often limited as they may have an adverse effect on the operation of distribution *** of the operation challenges is the interaction between DG and voltage-control equipment,e.g.,an under-load tap changer(ULTC),which is basically designed to compensate for voltage changes caused by slow load *** integration of variable DGs leads to rapid voltage fluctuations,which can negatively affect the tap operation of *** paper investigates the impact of high penetration levels of RDG on the tap operation of ULTC in distribution networks through *** mitigation techniques that can alleviate this impact are also *** these techniques,constant power-factor mode is regarded as the best trade-off between the simplicity and effectiveness of minimizing the number of tap *** are performed on a Canadian benchmark rural distribution feeder using OpenDss software.

关键词： Renewable energy distributed generation(DG) voltage regulator load tap changer distribution network.

spirulina platensis extract improves the production and defenses of the common bean grown in a heavy metals-contaminated saline soil

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental sciences 2023年第7期129卷 240-257页

作者： Mostafa M.Rady ahmed s.elrys Eman selem ahmed A.A.Mohsen safaa M.A.I.Arnaout ahmed H.el-sappah Khaled A.el-Tarabily el-sayed M.Desoky Botany Department Faculty of AgricultureFayoum UniversityFayoum 63514Egypt College of Tropical Crops Hainan UniversityHaikou 570228China soil science Department Faculty of AgricultureZagazig UniversityZagazig 44511Egypt Botany and Microbiology Department Faculty of ScienceZagazig UniversityZagazig 44511Egypt Horticulture Department Faculty of AgricultureZagazig UniversityZagazig 44511Egypt Botany Department Faculty of AgricultureZagazig UniversityZagazig 44511Egypt Genetics Department Faculty of AgricultureZagazig UniversityZagazig 44511Egypt Department of Biology College of ScienceUnited Arab Emirates UniversityAl-Ain 15551United Arab Emirates Khalifa Center for Genetic Engineering and Biotechnology United Arab Emirates UniversityAl-Ain 15551United Arab Emirates Harry Butler Institute Murdoch UniversityMurdoch 6150Australia

Plants have to cope with several abiotic stresses,including salinity and heavymetals(HMs).Under these stresses,several extracts have been used as effective natural biostimulants,however,the use of spirulina platensis(sP)extract(sPE)remains *** effects of sPE were evaluated as soil addition(sA)and/or foliar spraying(Fs)on antioxidant defenses and HMs content of common bean grown in saline soil contaminated with ***(40 or 80 mg sPE/hill added as sA or 20 or 40 mg sPE/plant added as Fs)or integrative(sA+Fs)applications of sPE showed significant improvements in the following order:sA-80+Fs-40>sA-80+Fs-20>sA-40+Fs-40>sA-40+Fs-20>sA-80>sA-40>Fs-40>Fs-20>***,the integrative sA+Fs with 40 mg sP/plant was the most effective treatment in increasing plant growth and production,overcoming stress effects and minimizing contamination of the edible *** significantly increased plant growth(74%–185%)and yield(107%–227%)by enhancing net photosynthetic rate(78.5%),stomatal conductance(104%),transpiration rate(124%),and contents of carotenoids(60.0%),chlorophylls(49%–51%),and NPK(271%–366%).These results were concurrent with the marked reductions in malondialdehyde(61.6%),hydrogen peroxide(42.2%),nickel(91%–94%),lead(80%–9%),and cadmium(74%–91%)contents due to the improved contents of glutathione(87.1%),ascorbate(37.0%),andα-tocopherol(77.2%),and the activities of catalase(18.1%),ascorbate peroxidase(18.3%),superoxide dismutase(192%),and glutathione reductase(52.2%)as reinforcing ***,this most effective treatment is recommended to mitigate the stress effects of salinity and HMs on common bean production while minimizing HMs in the edible part.

关键词： Antioxidant defense system Biostimulants Heavy metals Microalgae extracts saline soil soil pollution