检索结果-南通市图书馆

含能材料 2019年第1期27卷 21-27,90页

作者： Ahmed M Enew ehab abadir Sahar Elmarsafy Karim K Elsharkawy Chemical Department Faculty of EngineeringCairo University School of Chemistry and Environment Beijing University of Aeronautics and Astronautics

The effects of plasticizers,antioxidants and burning rate modifiers on the aging performance of the composite solid propellant based on hydroxyl-terminated polybutadiene(HTPB)/hexamethylene diisocyanate(HMDI)were explored by apply-ing an accelerated aging program for 90 day at 70 ℃. The HTPB propellant matrix with the diisooctyl sebacate(DOS)as plasti-cizers and diisooctyl azelate(DOZ), antioxidants as N,N ′-Diphenyl-p-phenylenediamine(AO) and 2,2′-methylenebis(4-methyl-6-tert-butylphenol)(cyanox 2246)and burning rate modifiers as barium ferrite(BF),copper chromites(CC)and fer-ric oxide(FO)were varied. Results show that sample(S1)which based on DOS decreases the stress value and increases the strain value which considered to be an excellent start for aging program. Sample(S3)containing AO presents the higher resis-tance to oxidation showing the better performance that reflects on increasing the shelf life of the composite solid propellant mo-tor. Sample(S5)which based on BF enhances the ballistic performance among over the other tested two samples. The accelerat-ed aging program allowed us to estimate the motor in-service lifetime.

关键词： polybutadiene(HTPB)/hexamethylene diisocyanate(HMDI)composite solid propellant plasticizers antioxidants burning rate modifiers aging program

Thermal performance of domed roof in air-conditioned spaces

在线全文

学校读者我要写书评

暂无评论

Energy and Built Environment

Energy and Built Environment 2024年第2期5卷 270-287页

作者： Ibrahim Reda Raouf N.AbdelMessih Mohamed Steit ehab M.Mina Mechanical Power Engineering Faculty of EngineeringAin Shams University1 El-Sarayat St.Cairo 11517Egypt Architectural Engineering Faculty of EngineeringAin Shams UniversityCairoEgypt

Due to their thermal performance,domed roofs are one of the passive solutions that affect energy consumption in buildings.The thermal performance of domed roofs has been investigated in many naturally ventilated spaces.However,few studies have discussed their performance in conditioned spaces.Therefore,this study introduces a computational comparison between domed and flat roofs to investigate their impact on thermal comfort inside a conditioned mosque.At an earlier stage,field measurements were carried out inside a Bahraini mosque to acquire its indoor air conditions during the summer period of 2021,in addition to validating the computational model.The findings of this study confirm that,under mechanical cooling conditions,the flat roof offers a lower indoor temperature than the domed roof by 0.4℃and 0.1℃for open and closed doors,respectively.Similarly,the air velocity is lower by approximately 0.01 m/s for both door modes.The overall PMV values of the flat roof are also lower by 0.07 and 0.01,while the PPD values are lower by 0.20,and 0.34 for open and closed doors,respectively.Based on these small differences,it can be concluded that the thermal performance of both roofing systems behaves equally in conditioned spaces.However,the air patterns are substantially different,the overall thermal performance is similar.This similarity drives building designers to rethink the thermal performance of the domed roofs in air-conditioned spaces with such a hot climate,regardless of their aesthetic and acoustical behaviour.

关键词： Thermal comfort Computational fluid dynamics(CFD) Predicted mean vote(PMV)and predicted percentage dissatisfied(PPD) Domed roof Flat roof

Transcriptomic and bioinformatics analysis of the mechanism by which erythropoietin promotes recovery from traumatic brain injury in mice

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2024年第1期19卷 171-179页

作者： Weilin Tan Jun Ma Jiayuanyuan Fu Biying Wu Ziyu Zhu Xuekang Huang Mengran Du Chenrui Wu ehab Balawi Qiang Zhou Jie Zhang Zhengbu Liao Department of Neurosurgery The First Affiliated Hospital of Chongqing Medical UniversityChongqingChina

Recent studies have found that erythropoietin promotes the recovery of neurological function after traumatic brain injury.However,the precise mechanism of action remains unclea r.In this study,we induced moderate traumatic brain injury in mice by intrape ritoneal injection of erythro poietin for 3 consecutive days.RNA sequencing detected a total of 4065 differentially expressed RNAs,including 1059 mRNAs,92 microRNAs,799 long non-coding RNAs,and 2115circular RNAs.Kyoto Encyclopedia of Genes and Genomes and Gene Ontology analyses revealed that the coding and non-coding RNAs that were differentially expressed after traumatic brain injury and treatment with erythropoietin play roles in the axon guidance pathway,Wnt pathway,and MAPK pathway.Constructing competing endogenous RNA networks showed that regulatory relationship between the differentially expressed non-coding RNAs and mRNAs.Because the axon guidance pathway was repeatedly enriched,the expression of Wnt5a and Ephb6,key factors in the axonal guidance pathway,was assessed.Ephb6 expression decreased and Wnt5a expression increased after traumatic brain injury,and these effects were reversed by treatment with erythro poietin.These findings suggest that erythro poietin can promote recove ry of nerve function after traumatic brain injury through the axon guidance pathway.

关键词： axon guidance bioinformatics analysis competing endogenous RNA erythropoietin Gene Ontology Kyoto Encyclopedia of Genes and Genomes non-coding RNA RNA sequencing transcriptomics traumatic brain injury

Endoscopic Assisted Eyebrow Craniotomy for Anterior Cranial Fossa Lesions: Clinical and Cosmetic Outcomes

在线全文

学校读者我要写书评

暂无评论

Open Journal of Modern Neurosurgery 2024年第1期14卷 30-47页

作者： Ahmed Hosameldin Hesham Elshetany ehab Abdelhalim Department of Neurosurgery Faculty of Medicine Fayoum University Fayoum Egypt Department of Neurosurgery Faculty of Medicine Cairo University Cairo Egypt

Background: The eyebrow supraorbital keyhole approach could be considered a modified minimally invasive model for the classic pterional subfrontal approach in which an eyebrow incision and supraorbital mini craniotomy are performed for exposure of the anterior cranial fossa corridor. Methods: This study was retrospectively conducted on twenty four patients, age ranging from 20 to 65 years old, with anterior cranial fossa lesions who were meeting the eligibility criteria for eyebrow craniotomy in the period from August 2019 to January 2023. These patients were operated through eyebrow supraorbital approach in which microscopic endoscopic assisted technique were used. Extent of resection, clinical and cosmetic outcomes and complication incidence were assessed. Results: We included the twenty four patients who met inclusion criteria (17 females and 7 males) their ages ranged from 20 to 65 years. The most common pathology was meningioma in 19 patients. Two patients experienced supraorbital loss of sensation and only one patient experienced palsy of frontalis branch of facial nerve. Frontal sinus was breached in 3 patients with no patient experienced postoperative CSF leak. Total excision was accomplished for 23 patients. Four patients who had preoperative visual compromise, improvement of visual acuity and field defects was observed in 3 patients. No major intraoperative complications occurred. All patients filled cosmetic satisfaction questionnaire during their outpatient visits. For the eyebrow supraorbital approach, no incision related intolerable pain, no craniotomy defects or irregularities, no cosmetic complaints nor limitation of jaw opening were reported, and only minor symptoms in the form of limited eyebrow elevation, swelling and numbness in the forehead. Conclusions: The eyebrow craniotomy could be used safely as a more cosmetic and minimally invasive approach for a variety of anterior cranial fossa lesions. Endoscopic assistance has been found very useful for deeply seated lesions and hidden residuals wi

关键词： Eyebrow Supraorbital Approach Keyhole Craniotomy Microscopic Endoscopic Minimally Invasive

Identifying and validating MMP family members(MMP2,MMP9,MMP12,and MMP16)as therapeutic targets and biomarkers in kidney renal clear cell carcinoma(KIRC)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Oncology Research 2024年第4期32卷 737-752页

作者： KUNLUN LI DANDAN LI BARBOD HAFEZ MOUNIR M.SALEM BEKHIT YOUSEF A.BIN JARDAN FARS KAED ALANAZI ehab I.TAHA SAYED H.AUDA FAIQAH RAMZAN MUHAMMAD JAMIL The Second Affiliated Hospital of Harbin Medical University Harbin Medical UniversityHarbinChina Department of Pharmaceutical Engineering Jiangsu Ocean UniversityLianyungangChina Department of Biological Engineering University of SalfordSalfordUK Department of Pharmaceutics College of PharmacyKing Saud UniversityRiyadhSaudi Arabia Department of Animal and Poultry Production Faculty of Veterinary and Animal SciencesGomal UniversityDera Ismail KhanPakistan Department of Arid Zone Research PARC instituteDera Ismail KhanPakistan

Kidney Renal Clear Cell Carcinoma(KIRC)is a malignant tumor that carries a substantial risk of morbidity and mortality.The MMP family assumes a crucial role in tumor invasion and metastasis.This study aimed to uncover the mechanistic relevance of the MMP gene family as a therapeutic target and diagnostic biomarker in Kidney Renal Clear Cell Carcinoma(KIRC)through a comprehensive approach encompassing both computational and molecular analyses.STRING,Cytoscape,UALCAN,GEPIA,OncoDB,HPA,cBioPortal,GSEA,TIMER,ENCORI,DrugBank,targeted bisulfite sequencing(bisulfite-seq),conventional PCR,Sanger sequencing,and RT-qPCR based analyses were used in the present study to analyze MMP gene family members to accurately determine a few hub genes that can be utilized as both therapeutic targets and diagnostic biomarkers for KIRC.By performing STRING and Cytohubba analyses of the 24 MMP gene family members,MMP2(matrix metallopeptidase 2),MMP9(matrix metallopeptidase 9),MMP12(matrix metallopeptidase 12),and MMP16(matrix metallopeptidase 16)genes were denoted as hub genes having highest degree scores.After analyzing MMP2,MMP9,MMP12,and MMP16 via various TCGA databases and RT-qPCR technique across clinical samples and KIRC cell lines,interestingly,all these hub genes were found significantly overexpressed at mRNA and protein levels in KIRC samples relative to controls.The notable effect of the up-regulated MMP2,MMP9,MMP12,and MMP16 was also documented on the overall survival(OS)of the KIRC patients.Moreover,targeted bisulfite-sequencing(bisulfite-seq)analysis revealed that promoter hypomethylation pattern was associated with up-regulation of hub genes(MMP2,MMP9,MMP12,and MMP16).In addition to this,hub genes were involved in various diverse oncogenic pathways.The MMP gene family members(MMP2,MMP9,MMP12,and MMP16)may serve as therapeutic targets and prognostic biomarkers in KIRC.

关键词： KIRC MMP gene family Chemotherapy Overall survival

Combining ability of Egyptian cotton(Gossypium barbadense L.)reveals genetic potential for improved yield and fiber quality

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Cotton Research 2024年第2期7卷 109-122页

作者： Abdelghany Ahmed M. El-Banna Aly A.A. Lamlom Sobhi F El-Sorady Gawhara A. Salama ehab A.A. Ren Honglei Shaibu Abdulwahab S. Yehia Waleed M.B. Crop Science Department Faculty of AgricultureDamanhour UniversityDamanhour 22516Egypt Plant Production Department Faculty of Agriculture Saba BashaAlexandria UniversityAlexandria 21531Egypt Agricultural Botany Department Faculty of Agriculture Saba BashaAlexandria UniversityAlexandria 21531Egypt Heilongjiang Academy of Agricultural Sciences Soybean Research InstituteHarbin 150086China Department of Agronomy Bayero University KanoKano 700001Nigeria Cotton Breeding Department Cotton Research InstituteAgriculture Research CenterGizaEgypt

Background As the most widely cultivated fiber crop,cotton production depends on hybridization to unlock the yield potential of current varieties.A deep understanding of genetic dissection is crucial for the cultivation of enhanced hybrid plants with desired traits,such as high yield and fine fiber quality.In this study,the general combining ability(GCA)and specific combining ability(SCA)of yield and fiber quality of nine cotton parents(six lines and three testers)and eighteen F1 crosses produced using a line×tester mating design were analyzed.Results The results revealed significant effects of genotypes,parents,crosses,and interactions between parents and crosses for most of the studied traits.Moreover,the effects of both additive and non-additive gene actions played a notably significant role in the inheritance of most of the yield and fiber quality attributes.The F1 hybrids of(Giza 90×Aust)×Giza 86,Uzbekistan 1×Giza 97,and Giza 96×Giza 97 demonstrated superior performance due to their favorable integration of high yield attributes and premium fiber quality characteristics.Path analysis revealed that lint yield has the highest positive direct effect on seed cotton yield,while lint percentage showed the highest negative direct effect on seed cotton yield.Principal component analysis identified specific parents and hybrids associated with higher cotton yield,fiber quality,and other agronomic traits.Conclusion This study provides insights into identifying potential single-and three-way cross hybrids with superior cotton yield and fiber quality characteristics,laying a foundation for future research on improving fiber quality in cotton.

关键词： Gossypium barbadense L. Combining ability Seed cotton yield Fiber quality Cluster analysis Path analysis

Adsorptive removal of iron and manganese ions from aqueous solutions with microporous chitosan/polyethylene glycol blend membrane

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2012年第8期24卷 1425-1432页

作者： Neama A.Reiad Omar E.Abdel Salam ehab F.abadir Farid A.Harraz Sanitary&Environmental Department Housing&Building National Research Center87 el Tahrir st.DokkiEgypt Department of Chemical Engineering Faculty of EngineeringCairo UniversityGizaEgypt Advanced Materials Technology Department Central Metallurgical R&D InstituteHelwanEgypt

Microporous chitosan （CS） membranes were directly prepared by extraction of poly（ethylene glycol）（PEG） from CS/PEG blend membrane and were examined for iron and manganese ions removal from aqueous solutions. The different variables affecting the adsorption capacity of the membranes such as contact time, pH of the sorption medium, and initial metal ion concentration in the feed solution were investigated on a batch adsorption basis. The affinity of CS/PEG blend membrane to adsorb Fe（II） ions is higher than that of Mn（II） ions, with adsorption equilibrium achieved after 60 min for Fe（II） and Mn（II） ions. By increasing CS]PEG ratio in the blend membrane the adsorption capacity of metal ions increased. Among all parameters, pH has the most significant effect on the adsorption capacity, particularly in the range of 2.9-5.9. The increase in CS/PEG ratio was found to enhance the adsorption capacity of the membranes. The effects of initial concentration of metal ions on the extent of metal ions removal were investigated in detail. The experimental data were better fitted to Freundlich equation than Langmuir. In addition, it was found that the iron and manganese ions adsorbed on the membranes can be effectively desorbed in 0.1 mol/L HCl solution （up to 98% desorption efficiency） and the blend membranes can be reused almost without loss of the adsorption capacity for iron and manganese ions.

关键词： chitosan blend membrane iron and manganese ions adsorption

Metaheuristic Lightweight Cryptography for Security Enhancement in Internet of Things

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2022年第8期72卷 3009-3023页

作者： Mahmoud Ragab ehab Bahaudien Ashary Information Technology Department Faculty of Computing and Information TechnologyKing Abdulaziz UniversityJeddah21589Saudi Arabia Centre of Artificial Intelligence for Precision Medicines King Abdulaziz UniversityJeddah21589Saudi Arabia Mathematics Department Faculty of ScienceAl-Azhar UniversityNaser City11884CairoEgypt Electrical and Computer Engineering Department Faculty of EngineeringKing Abdulaziz UniversityJeddah21589Saudi Arabia

The advancements made in Internet of Things(IoT)is projected to alter the functioning of healthcare industry in addition to increased penetration of different applications.However,data security and private are challenging tasks to accomplish in IoT and necessary measures to be taken to ensure secure operation.With this background,the current paper proposes a novel lightweight cryptography method for enhance the security in IoT.The proposed encryption algorithm is a blend of Cross Correlation Coefficient(CCC)and Black Widow Optimization(BWO)algorithm.In the presented encryption technique,CCC operation is utilized to optimize the encryption process of cryptography method.The projected encryption algorithm works in line with encryption and decryption processes.Optimal key selection is performed with the help of Artificial Intelligence(AI)tool named BWO algorithm.With the combination of AI technique and CCC operation,optimal security operation is improved in IoT.Using different sets of images collected from databases,the projected technique was validated in MATLAB on the basis of few performance metrics such as encryption time,decryption time,Peak Signal to Noise Ratio(PSNR),CC,Error,encryption time and decryption time.The results were compared with existing methods such as Elliptical Curve cryptography(ECC)and Rivest-Shamir-Adleman(RSA)and the supremacy of the projected method is established.

关键词： Security images encryption time correlation coefficient black widow optimization artificial intelligence decryption time

d-EMR:Secure and distributed Electronic Medical Record management

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

高置信计算(英文)

高置信计算(英文) 2023年第1期3卷 47-57页

作者： ehab Zaghloul Tongtong Li Jian Ren Department of Electrical and Computer Engineering Michigan State UniversityUSA

As more and more data is produced,finding a secure and efficient data access structure has become a major research issue.The centralized systems used by medical institutions for the management and transfer of Electronic Medical Records(EMRs)can be vulnerable to security and privacy threats,often lack interoperability,and give patients limited or no access to their own EMRs.In this paper,we first propose a privilege-based data access structure and incorporates it into an attribute-based encryption mechanism to handle the management and sharing of big data sets.Our proposed privilege-based data access structure makes managing healthcare records using mobile healthcare devices efficient and feasible for large numbers of users.We then propose a novel distributed multilevel EMR(d-EMR)management scheme,which uses blockchain to address security concerns and enables selective sharing of medical records among staff members that belong to different levels of a hierarchical institution.We deploy smart contracts on Ethereum blockchain and utilize a distributed storage system to alleviate the dependence on the record-generating institutions to manage and share patient records.To preserve privacy of patient records,our smart contract is designed to allow patients to verify attributes prior to granting access rights.We provide extensive security,privacy,and evaluation analyses to show that our proposed scheme is both efficient and practical.

关键词： Privilege-based access Hierarchy Attribute-based encryption EMRs Distributed data sharing Blockchain Smart contract

GREEN SYNTHESIS OF ANTIBACTERIAL CHITOSAN FILMS LOADED WITH SILVER NANOPARTICLES

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2013年第7期31卷 984-993页

作者： Neama A. Reiad Omar E. Abdel Salam ehab F. abadir Farid A. Harraz Sanitary & Environmental Engineering Department Housing & Building National Research Center Department of Chemical Engineering Faculty of EngineeringCairo University Advanced Materials Technology Department Central Metallurgical R & D Institute

An eco-friendly chemical reduction method was successfully used for the preparation of chitosan （CTS） composite films loaded with silver nanoparticles （AgNPs） by self assembly method using poly（ethylene glycol） as both reducing and stabilizing agent. UV-Vis spectra of the prepared chitosan loaded silver nanoparticles （CTSLAg） films reveal that full reduction of silver ions to silver nanoparticles takes place at 90 ℃. The effect of reaction conditions on the silver nanoparticles formation was investigated using UV-Vis spectrophotometer. The morphology of the films was tested by scanning electron microscopy （SEM）. The DSC curves showed that the CTSLAg film had a favorable compatibility and heat stability. AgNPs were confirmed by XRD and UV-Vis spectroscopy. The TEM findings revealed that the silver nanoparticles synthesized were spherical in shape with uniform dispersal, and by increasing CTS：PEG ratio larger silver nanoparticles could be obtained. The results of antibacterial study reveal that the prepared nanoeomposite films exhibited potential inhibition.

关键词： Chitosan Silver nanoparticles Antibacterial activity.