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Chinese Journal of Polymer Science 2010年第3期28卷 305-310页

作者： Ahmed Aouissi Salim Salem al-Deyab hassan al-shehri Chemistry Department College of ScienceKing Saud UniversityRiyadhKSA

Three Keggin-type heteropolyanions, namely H3PMo12O40-13H2O, （NH4）3PMo12O40·4H2O and H3PW12O40·13H2O were prepared and tested in the ring-opening polymerization reaction of tetrahydrofuran. The effects of the counter-cation （H＋, NH4＋） and the peripheral atoms （Mo, W） on the polymerization were investigated. It has been found that when the protons of H3PMo12O40·13H2O were replaced by the ammonium cations the polymerization rate decreased dramatically. Whereas, when the peripheral atoms （Mo） were replaced by their homologous （W）, the polymerization rate increased twofold. As for the viscosity average molecular weight （My） of polymer products, it was found that the high molecular weight （7930） was obtained by using H3PW12O40·13H2O. The molecular weight （My） obtained by H3PMo12O40·13H2O and （NH4）H3PMo12O40·13H2O was 6470 and 6810, respectively.

关键词： Tetrahydrofuran Heteropoly compounds Ring opening polymerization Cyclic ether Solid acid

A Weighted Spatially Constrained Finite Mixture Model for Image Segmentation

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Computers, Materials & Continua 2021年第4期67卷 171-185页

作者： Mohammad Masroor Ahmed Saleh al shehri Jawad Usman Arshed Mahmood Ul hassan Muzammil Hussain Mehtab Afzal Department of Computer Science Capital University of Science&TechnologyIslamabad45730Pakistan Department of Computer Science Jubail University CollegeJubail31961Saudi Arabia Department of Computer Science University of BaltistanSkardu16100Pakistan Department of Computer Skills Preparatory Year Najran University1988Saudi Arabia Department of Computer Science University of Management&TechnologyLahore54782Pakistan Department of Computer Science University of LahoreLahore54500Pakistan

Spatially Constrained Mixture Model(SCMM)is an image segmentation model that works over the framework of maximum a-posteriori and Markov Random Field(MAP-MRF).It developed its own maximization step to be used within this *** research has proposed an improvement in the SCMM’s maximization step for segmenting simulated brain Magnetic Resonance Images(MRIs).The improved model is named as the Weighted Spatially Constrained Finite Mixture Model(WSCFMM).To compare the performance of SCMM and WSCFMM,simulated T1-Weighted normal MRIs were segmented.A region of interest(ROI)was extracted from segmented *** similarity level between the extracted ROI and the ground truth(GT)was found by using the Jaccard and Dice similarity measuring *** to the Jaccard similarity measuring method,WSCFMM showed an overall improvement of 4.72%,whereas the Dice similarity measuring method provided an overall improvement of 2.65%against the ***,WSCFMM signicantly stabilized and reduced the execution time by showing an improvement of 83.71%.The study concludes that WSCFMM is a stable model and performs better as compared to the SCMM in noisy and noise-free environments.

关键词： Finite mixture model maximum aposteriori Markov random eld image segmentation

Investigation into the effect of silica nanoparticles on the rheological characteristics of water-in-heavy oil emulsions

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Petroleum Science 2019年第6期16卷 1374-1386页

作者： O.S.alade D.A.al shehri M.Mahmoud Department of Petroleum Engineering College of Petroleum and GeosciencesKing Fahd University of Minerals and PetroleumDhahranSaudi Arabia

The effect of silica nanoparticles on the rheological characteristics of water-in-heavy oil emulsions has been *** oil recovery methods for heavy oil production(most especially,thermal fluid injection)usually result in the formation of water-in-oil(W/O)*** reality,the emulsion produced also contains some fine solid mineral particles such as silica,which,depending on its quantity,may alter the viscosity and/or rheological properties of the fluid.A series of binary-component emulsions were separately prepared by dispersing silica nanoparticles[phase fraction,βs,=0.5%–5.75%(wt/v)]in heavy oil(S/O suspension)and by dispersing water[water cut,θw=10%–53%(v/v)]in heavy oil(W/O emulsion).Ternary-component emulsions comprising heavy oil,water droplets and suspended silica nanoparticles(S/W/O)were also prepared with similar ranges ofθw andβ*** viscosity was measured at different shear rates(5.1–1021.4 s-1)and temperatures(30–70°C).Both binary-component and ternary-component emulsion systems were observed to exhibit nonNewtonian shear thinning *** viscosity of the heavy oil and W/O emulsions increased in the presence of silica *** effect was,however,less signifi cant belowβs=2%(wt/v).Moreover,a generalized correlation has been proposed to predict the viscosity of both binary-component and ternary-component emulsions.

关键词： Heavy oil emulsions Heavy oil–silica nanoparticle suspension Viscosity functions Rheological model Complex fluid

A significant improvement in adsorption behavior of mesoporous TUD-1 silica through neodymium incorporation

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Journal of Rare Earths 2021年第4期39卷 469-476页

作者： Badria M.al-shehri Sahar K.Mohamed Shaykha alzahly Mohamed S.Hamdy Catalysis Research Group(CRG) Department of ChemistryCollage of ScienceKing Khalid UniversityP.O.Box 2009Abha61413Saudi Arabia Chemistry Department Collage of ScienceUmm Al-Qura UniversityMakkah21421Saudi Arabia Chemistry Department Faculty of ScienceHelwan UniversityAin HelwanCairo11795Egypt King Abdullah Institute for Nanotechnology King Saud UniversityRiyadh11451Saudi Arabia

Neodymium was incorporated into the three-dimensional mesoporous siliceous material *** order to understand the chemical and morphological structure of the prepared material,several characterization techniques were *** characterization results show the formation of highly distributed isolated Nd3+ions incorporated in the silica matrix in tetrahedrally coordinated structure,moreover no aggregation of separate phase(s)was/were *** prepared material was investigated as an adsorbent for methyl green(MG)dye in aqueous solution as a model cationic *** results show higher adsorption capacity for Nd-TUD-1 by almost 24 times higher than the neat parent TUD-1 material and more than 100 times higher than bulky Nd_(2)O_(3)under neutral *** adsorption results were fitted perfectly with pseudo-second-order ***,the adsorption isotherms were perfectly fitted with Freundlich isotherm model which indicates the formation of a multilayer of the dye molecules onto the Nd-TUD-1 surface as a physisorption with endothermic nature.

关键词： Adsorption Neodymium TUD-1 Mesoporous silica Water treatment Kinetics

URL Phishing Detection Using Particle Swarm Optimization and Data Mining

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Computers, Materials & Continua 2022年第12期73卷 5625-5640页

作者： Saeed M.alshahrani Nayyar Ahmed Khan Jameel almalki Waleed al shehri College of Computing and IT-Shaqra University Shaqra155572Saudi Arabia Department of Computer Science College of Computer in Al-LeithUmm Al-Qura UniversityMakkahSaudi Arabia

The continuous destruction and frauds prevailing due to phishing URLs make it an indispensable area for *** techniques are adopted in the detection process,including neural networks,machine learning,or hybrid techniques.A novel detection model is proposed that uses data mining with the Particle Swarm Optimization technique(PSO)to increase and empower the method of detecting phishing *** selection based on various techniques to identify the phishing candidates from the URL is *** this approach,the features mined from the URL are extracted using data mining *** features are selected on the basis of URL *** classification of these features identified by the data mining rules is done using PSO *** selection of features with PSO optimization makes it possible to identify phishing *** a large number of rule identifiers,the true positive rate for the identification of phishing URLs is maximized in this *** experiments show that feature selection using data mining and particle swarm optimization helps tremendously identify the phishing URLs based on the structure of the URL ***,it can minimize processing time for identifying the phishing website ***,the approach can be beneficial to identify suchURLs over the existing contemporary detecting models proposed before.

关键词： Phishing particle swarm optimization feature selection data mining classification cloud application

The Impact of Community-Based Awareness Campaigns on the Early Breast Examination among Women at King Faisal University

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Open Journal of Preventive Medicine 2015年第9期5卷 400-408页

作者： Omama al-shehri Collage of Medicine King Faisal University Al-Ahsa Kingdome of Saudi Arabia

Background and Objective: Breast cancer (BC) is the most common cancer between females in Saudi Arabia, the eastern area ranked as the first in the incidence rate. As the breast cancer awareness movement has expanded, majority of the new cases are still diagnosed in a later stage. This study aimed to evaluate the impact of breast cancer awareness campaigns on the knowledge and practice of early breast examination (EBE) which consisted of breast-self examination (BSE), clinical breast examination (CBE) and mammography, among women at King Faisal University. Methodology: A cross-sectional study carried out at King Faisal University, al-Hassa city on a sample of 300 adult females from different urban and rural areas. A pre-tested, self-administered questionnaire was distributed to the participants. The questionnaire contains questions about: socio-demographic factors, awareness campaigns, practice and knowledge of breast cancer and early screening methods. Results: The age of the participants ranged from 16 to 60 years;53% of the participants have attended campaigns;and 47% have never attended. Regarding the practice of BSE, CBE and mammography, the results were 8.8%, 3.3%, and 4.3%, respectively. The results show a significant relation between attending campaigns and good level of practice and knowledge. Conclusion and Recommendation: The findings indicate a great impact of the community-based awareness campaigns on the practice of EBE. The study recommends a multilevel intervention for every age group, specially the age group that at risk.

关键词： Breast Cancer Awareness Campaigns Examination Mammography

Quality of Life among Saudi Diabetics

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Journal of Diabetes Mellitus 2014年第3期4卷 225-231页

作者： Fahad S. al-shehri Joint Program of Family Medicine Abha KSA

Aim of study: To assess QOL among Saudi diabetics and to identify the possible risk factors associated with lower QOL. Patients and Methods: This study comprised 400 diabetic patients attending the Diabetes Clinic at theUniversityDiabetesCenterinRiyadh. They were interviewed using the Audit of Diabetes Dependent QOL (ADDQOL). Results: Most diabetic patients (78.7%) had negative (i.e., unfavorable) ADDQOL scores. Diabetic patients' age, education and occupation were not significantly associated with their QOL. Female patients had significantly worse QOL than male patients (p = 0.026). Married patients had significantly worse QOL compared with non-married patients (p = 0.012). Patients with type 2 diabetes had significantly worse QOL than those with type 1 diabetes (p = 0.029). Duration of diabetes was not significant factors as regard their QOL, with the worst QOL among those with more than 20 years of diabetes. The degree of diabetes control was significantly and directly associated with QOL score (p al characteristics associated with worse QOL among diabetics include female gender, and being married. Disease characteristics associated with worse QOL include being a type 2 diabetic and those with uncontrolled diabetes. Main complications associated with worse QOL among diabetics include retinopathy, diabetic foot and neuropathy.

关键词： Quality of Life Diabetes Mellitus Retinopathy Nephropathy Neuropathy Diabetic Foot

Glycemic Control and Microvascular Complications of Type 2 Diabetes among Saudis

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Journal of Diabetes Mellitus 2019年第4期9卷 167-175页

作者： Fahad S. al-shehri University Diabetes Center Riyadh KSA

Objective: To study the relation between level of glycemic control and different micovascular complications of type 2 diabetes among Saudis. Patients and Methods: This hospital-based study analyzed the medical records of 343 type 2 diabetic patients attending the “University Diabetes Center” in “King Abdul-Aziz” University Hospital, in Riyadh City within 2006. Inclusion criteria comprised being adult, Saudi, type 2 diabetic, whose disease duration is more than one year, non-pregnant (for females). Results: Half of patients (50.4%) were not controlled (HbA1c > 8%). Vascular complications of diabetes were mainly retinopathy (45.8%) or neuropathy (32.7%). Prevalence of nephropathy was 9.9%. Patients’ sex, age, marital status and occupation were not significant variables as regard their control of diabetes. Patient’s educational status was significantly associated with degree of diabetes control;the higher the patient’s education the better the glycemic control (p = 0.002). Moreover, the longer the duration of diabetes, the worse the glycemic control (p Conclusions: Glycemic control among type 2 diabetics is a real challenge that should the health care team face in tertiary-care diabetes centers in KSA. Microvascular complications are common, especially among poorly controlled cases. Recommendations: The current goal for glycemic control at the University Diabetes Center (HbA1c alence of failure of diabetes control should be investigated. There should be national campaigns to raise the public awareness as regard diabetes and also screening for hyperglycemia for the sake of early diagnosis of diabetes so as to minimize the incidence of diabetes complications.

关键词： Type 2 Diabetes Glycemic Control Microvascular Complications

Oral health status of older people in residential homes in Saudi Arabia

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Open Journal of Stomatology 2012年第4期2卷 307-313页

作者： Sharifa A. M. al-shehri Department of Prosthetic Dental Sciences College of Dentistry King Saud University Riyadh KSA

The aim of the study was to de-termine the oral health status and treatment needs of elderly residents of residential homes in Riyadh, Saudi Arabia. Methods: Among 129 elderly residents, 83 (51 males, and 32 females) of them were interviewed and clini-cally examined according to WHO criteria by two calibrated dentists. Results: The mean age of the subjects was 72 ± 8.5. Male subjects had a higher smoking rate than females. Among elderly subjects below 74 years old, 20.8% had a functional dentition (> or = 20), while only 6.7% for those aged greater or equal to 75 years (p = 0.0004). Mean number of the sound teeth in all subjects was 6.7 ± 8.5. The mean number of DMFT was 18.6 ± 12.6. The missing component was the highest (16 ± 13) for both genders. The mean number of decayed roots was 2.75 ± 3.95 in males and 0.63 ± 1.96 in females. Overall, males had more sound and decayed teeth and less filled and missed teeth than females. There was no significant difference between males and females in periodontal problems except the calculus scores. The majority of subjects in need for tooth extraction were male subjects. With no gender difference 63% were in need for restorations, 40% needed upper and lower full dentures. Need for partial dentures was 38% upper and 48% lower. Conclusion: The oral health of the institutionalized elderly population in Saudi Arabia is generally poor and their treatment needs are high.

关键词： Older People Oral Health Status Residential Homes Treatment Needs

Changing patterns of hepatitis A prevalence within the Saudi population over the last 18 years

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World Journal of Gastroenterology 2008年第48期14卷 7371-7375页

作者： Faleh al Faleh Suliman al shehri Saleh al Ansari Mohammed al Jeffri Yaqoub al Mazrou Ahmad Shaffi Ayman A Abdo Department of Medicine College of Medicine King Saud University Ministry of Education Ministry of Health Department of Community Medicine College of Medicine King Saud University

AIM： To determine the seroprevalence of Hepatitis A （HAV） amongst Saudi children and compare it with previously reported prevalence data from the same population. METHODS： A total of 1357 students were randomly selected between the ages of 16 and 18 years （689 males and 668 females） from three different regions of Saudi Arabia （Madinah, AI-Qaseem, and Aseer） and tested for ***： The overall prevalence of anti-HAV-IgG among the study population was 18.6%. There was no difference between males and females but there was a significant difference in the seroprevalence （P = 0.0001） between the three different regions, with Madinah region showing the highest prevalence （27.4%）. When classified according to socioeconomic status, lower class students had a prevalence of 36.6%, lower middle class 16.6%, upper middle class 9.6%, and upper class 5.9% （P = 0.0001）. Comparing the current study results with those of previous studies in 1989 and 1997 involving the same population, there was a marked reduction in the overall prevalence of HAV from 52% in 1989, to 25% in 1997, to 18.6% in 2008 （P 〈 0.0001）.CONCLUSION： Over the last 18 years, there has been a marked decline in the prevalence of HAV in Saudi children and adolescents. The current low prevalence rates call for strict adherence to vaccination policies in high-risk patients and raises the question of a universal HAV vaccination program.

关键词： Hepatitis A Saudi Arabia Epidemiology Prevalence Serology