http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Ola Mohamed (검색결과 14 건)
- 무료
- 기관 내 무료
- 유료
-
Ola Mohamed Rehan,Hoda Abdel Kader Saleh,Hala Ahmed Raffat,Noha Saleh Abu-Taleb 대한영상치의학회 2018 Imaging Science in Dentistry Vol.48 No.1
Purpose: To evaluate osseous changes of temporomandibular joint (TMJ) in patients with rheumatoid arthritis (RA) using cone-beam computed tomography (CBCT) and to correlate the imaging findings with the severity of TMJ dysfunction, clinical findings, and laboratory findings. Materials and Methods: This study consisted of 28 subjects, including 14 RA patients and 14 controls, who were scheduled to undergo CBCT imaging for the diagnosis of a complaint not related to or affecting the TMJ. The Fonseca’s questionnaire was used to assess the severity of TMJ dysfunction. Rheumatoid factor (RF) and the erythrocyte sedimentation rate (ESR) were assessed in the RA patients. CBCT was then performed in all subjects and osseous TMJ abnormalities were assessed. Results: According to the Fonseca’s questionnaire, 14.3% of the patients had no TMJ dysfunction, while 50%, 21.4%, and 14.3% had mild, moderate, and severe dysfunction, respectively. RF was positive in 64.3% of patients, and the ESR level was high in 100%. Imaging findings revealed a statistically significantly higher prevalence of erosion (85.7%), flattening (89.3%), osteophyte formation (32.1%), subchondral cyst (32.1%), sclerosis (64.3%), and condylar irregularities (28.6%) in the RA patients than in the controls. No correlations were found between CBCT findings and the clinical findings, the severity of TMJ dysfunction, disease duration, or laboratory results. Conclusion: RA patients might show extensive osseous abnormalities with no/mild clinical signs or symptoms of TMJ dysfunction that necessitate TMJ imaging for these patients. CBCT is a valuable and efficient modality that can assess osseous TMJ changes in RA patients.
-
Ola A. Siam,Rabab A. Shanab,Mohamed A. Eltaher,Norhan A. Mohamed Techno-Press 2023 Advances in aircraft and spacecraft science Vol.10 No.3
This manuscript is dedicated to deriving the closed form solutions of free vibration of viscoelastic nanobeam embedded in an elastic medium using nonlocal differential Eringen elasticity theory that not considered before. The kinematic displacements of Euler-Bernoulli and Timoshenko theories are developed to consider the thin nanobeam structure (i.e., zero shear strain/stress) and moderated thick nanobeam (with constant shear strain/stress). To consider the internal damping viscoelastic effect of the structure, Kelvin/Voigt constitutive relation is proposed. The perforation geometry is intended by uniform symmetric squared holes arranged array with equal space. The partial differential equations of motion and boundary conditions of viscoelastic perforated nonlocal nanobeam with elastic foundation are derived by Hamilton principle. Closed form solutions of damped and natural frequencies are evaluated explicitly and verified with prestigious studies. Parametric studies are performed to signify the impact of elastic foundation parameters, viscoelastic coefficients, nanoscale, supporting boundary conditions, and perforation geometry on the dynamic behavior. The closed form solutions can be implemented in the analysis of viscoelastic NEMS/MEMS with perforations and embedded in elastic medium.
-
Assessment of stability of early loaded nano-coated hydroxyapatite implants in posterior maxilla
Ola Abdelsamad Amin,Ingy Mohamed Shehata,Heba Mohamed Kamel,Nader Nabil Elbokle 대한치과이식임플란트학회 2024 The Korean Academy of Implant Dentistry Vol.43 No.1
Purpose: This study assessed the stability of nano-coated hydroxyapatite implants in the posterior maxilla after early loading. Materials and Methods: This study was conducted on nine patients missing at least one maxillary posterior tooth. Ten nano-coated hydroxyapatite implants were inserted in nine patients and subjected to early loading according to the secondary stability readings taken by Osstell®. The implant stability was measured at the time of implant insertion (T0), 4 (T1), 6 (T1 modified), weeks, and four months (T2) after surgery. Cone-beam computed tomography (CBCT) was performed in all patients before treatment started. Nine implants healed well, but one implant failed due to infection. Results: The secondary stability results six weeks after implant insertion were sufficient for implant loading. Significant differences were observed between T0, T1, T1 modified, and T2. Conclusions: Nano-coated hydroxyapatite implants are a good choice in the posterior maxilla because they allow early loading.
-
Rehan, Ola Mohamed,Saleh, Hoda Abdel Kader,Raffat, Hala Ahmed,Abu-Taleb, Noha Saleh Korean Academy of Oral and Maxillofacial Radiology 2018 Imaging Science in Dentistry Vol.48 No.1
Purpose: To evaluate osseous changes of temporomandibular joint (TMJ) in patients with rheumatoid arthritis (RA) using cone-beam computed tomography (CBCT) and to correlate the imaging findings with the severity of TMJ dysfunction, clinical findings, and laboratory findings. Materials and Methods: This study consisted of 28 subjects, including 14 RA patients and 14 controls, who were scheduled to undergo CBCT imaging for the diagnosis of a complaint not related to or affecting the TMJ. The Fonseca's questionnaire was used to assess the severity of TMJ dysfunction. Rheumatoid factor (RF) and the erythrocyte sedimentation rate (ESR) were assessed in the RA patients. CBCT was then performed in all subjects and osseous TMJ abnormalities were assessed. Results: According to the Fonseca's questionnaire, 14.3% of the patients had no TMJ dysfunction, while 50%, 21.4%, and 14.3% had mild, moderate, and severe dysfunction, respectively. RF was positive in 64.3% of patients, and the ESR level was high in 100%. Imaging findings revealed a statistically significantly higher prevalence of erosion (85.7%), flattening (89.3%), osteophyte formation (32.1%), subchondral cyst (32.1%), sclerosis (64.3%), and condylar irregularities (28.6%) in the RA patients than in the controls. No correlations were found between CBCT findings and the clinical findings, the severity of TMJ dysfunction, disease duration, or laboratory results. Conclusion: RA patients might show extensive osseous abnormalities with no/mild clinical signs or symptoms of TMJ dysfunction that necessitate TMJ imaging for these patients. CBCT is a valuable and efficient modality that can assess osseous TMJ changes in RA patients.
-
Mehrez E. El-Naggar,Ola A. Abu Ali,Dalia I. Saleh,K. M. Abu-alnja,Abd-allah M. Mnsour,Mohammed A. Abu-Saied,Tawfik A. Khattab 한국섬유공학회 2022 Fibers and polymers Vol.23 No.6
Despite the fact that Pyrovatex is widely used as a commercial flame-retardant, the release of toxic formaldehyderemains a serious problem. Fluorine-based compounds, on the other hand, have been employed to impart hydrophobic textilesurfaces, although they are exceedingly costly and poisonous. Based on those difficulties, we describe a simple one-stepmethod for coating electrically conductive cotton-nickel (Cot-Ni) blend fabric providing flame-retardant and water-repellentcharacteristics. A nickel ribbon was firstly bent around a cotton yarn as a core, and then woven into an electrically conductiveCot-Ni blend fabric, which was created by weaving the cotton-nikel hybrid threads with regular cotton yarns. The conductivefabric was coated with a composite consisting of silicone rubber (RTV) and ammonium polyphosphate (APP). The strongbinding of RTV with both APP and cotton fibres increased the flame-retardant action of cotton, according to the findings. Asa result, varied concentrations of APP were used in the composite to show that only 100 g/l of APP combined with RTVimproved the fire-retardancy. Depending on the concentration of APP, distinct hierarchical morphologies appeared on thesurface of the coated Cot-Ni fabrics. RTV also improved the hydrophobic character of the blend surface. Measurements of airpermeability, surface roughness, and stiffness were used to investigate the comfort qualities of the coated Cot-Ni blends. Eventually, those multifunctional (Cot-Ni)/RTV-APP textiles might be used in a variety of applications, such as grain storagecontainers, car seat mats, and firefighters' uniforms.
-
Samiha M. Abo El-Ola,Magda A. El-Bendary,Nasser H. Mohamed,Rehab M. Kotb 한국섬유공학회 2022 Fibers and polymers Vol.23 No.10
Functionalization of the textile surface plays a remarkable role in the synthetic fiber industry. This research isinterested in the one-step simultaneous functional finishing and transfer printing of alkaline-activated polyester fabric usingC.I. Disperse Red 60 and C.I. Disperse Blue 56. The optimum color depth was achieved using zinc oxide nanoparticle 0.5 %and nano polyurethane (50 g/l) in the finishing bath formulation, additionally, excellent ultraviolet protection (50+) category. Zinc oxide nanoparticles and zinc oxide/polyurethane nanocomposite finishing showed high antimicrobial efficiency. Theyshowed a microbial reduction of C. albicans (97 %), E. coli (93 and 96 %), and S. aureus (88 and 93 %), respectively. Thefinished polyester fabrics showed significant durability of protective properties for washing cycles after 25 washes. Theultraviolet protection maintained excellent category and enhanced ultraviolet protection factor values. The antimicrobialactivities after 25 washes achieved sustained microbial reduction percentage against the three tested microorganisms (C. albicans 92 and 87 %; E. coli 90 and 92 %; and S. aureus 87 and 81 %). The results showed the positive impact of zinc oxidenanoparticles and zinc oxide/polyurethane nanocomposite finishing on fastness to sublimation and light. At the same time,there is no change in the fastness of washing and perspiration. The effect of finishing formulations on the finished polyesterfabric samples' crucial mechanical properties was studied. These properties were fabric weight, thickness, tensile strength andelongation, and abrasion resistance. The obtained results showed that finishing polyester fabric samples with nanopolyurethane, zinc oxide nanoparticles, or zinc oxide/polyurethane nanocomposite did not alter the essential mechanicalproperties required for polyester fabric applications in textiles and apparel for different end uses. Additionally, the polyesterfabric surface was characterized using scanning electron microscopy and Fourier transform infrared spectroscopy, improvingthe functional finishing.
-
Preparation of Polyurethane Silicon Oxide Nanomaterials as a Binder in Leather Finishing
Hamed Elsayed,Rasha Attia,Ola Mohamed,Ahmed Haroun,Nabil El-Sayed 한국섬유공학회 2018 Fibers and polymers Vol.19 No.4
Leather finishing processes using toxic organic solvent based produce volatile organic compounds (VOC), chronic exposure to this chemicals effect on workers' health causing many diseases especially lung cancer. So, polyurethane waterbased was synthesized for application in leather finishing instead of organic solvent based because it’s economic and safety for industry and workers. Preparation of water-based polyurethane (PU) depends on the reaction of polyethylene glycol (PEG, 300) with isophorone diisocyanate (IPDI) and the reaction of IPDI-1,4-butanediol (BDO) together with dimethylolpropionic acid (DMPA), was synthesized by poly-addition polymerization reaction. PU was then modified with different amounts of silicon dioxide nanoparticles (1-5 % SiO2), used as a binder in leather finishing. Leather coated was characterized physically, chemically and thermally by FTIR, GPC, DLS, TEM, SEM and TGA. The results revel that, water vapor permeability (WVP) of leather coated with PU modified with SiO2 showed improvement due to the existence of SiO2 particles which increases the interspaces of the polyurethane coating. SEM showed that when the amount of SiO2 nanoparticles increases, there is uniform nanoparticles accumulated can be observed. EDX prove the presence of Si and O2 elements and the formation of SiO2 nanoparticles. Mechanical properties discussed that tensile strength; tear strength and elongation at break % increase with increase SiO2 concentration until 3 % SiO2 nanoparticles. TGA showed an improvement of thermal stability of coated leather modified with SiO2. Therefore, this study succeeded in preparation of safe, ecofriendly of water-based polyurethane binders which modified with SiO2 for using in leather finishing.
-
Ghareib, Hamada Ragab Abdo,Abdelhamed, Mohamed Sayed,Ibrahim, Ola Hammouda The Korean Society of Weed Science and The Turfgra 2010 Weed Biology and Management Vol.10 No.1
From the active acetone fraction of Chenopodium murale, vanillic acid was isolated and identified, based on $^1H$ and $^{13}C$ nuclear magnetic resonance spectral analyses. Free phenolic compounds inside the active acetone were qualified and quantified by using high performance liquid chromatography analysis, which revealed the presence of seven compounds with an abundance of vanillic and p-hydroxybenzoic acids. The allelopathic potential of the acetone fraction and vanillic acid was evaluated through laboratory bioassays against tomato plants. Our results showed that the allelopathic potential induced by low concentrations of the acetone fraction and vanillic acid stimulated the germination and growth of tomato and had stimulating effects on the activity of some antioxidant enzymes. We observed an enhancement in the activity of catalase, peroxidase, superoxide dismutase, and polyphenol oxidase, as well as the content of soluble protein and phenolic glycoside. Meanwhile, the levels of free phenolic compounds, $H_2O_2$, and lipid peroxidation decreased. The highest stimulations were recorded at 50 p.p.m. of acetone fraction and 0.5 p.p.m. of vanillic acid. In contrast, the highest concentrations exerted negative effects on all the measured parameters to record the maximum value of inhibition at 400 p.p.m. of acetone fraction and 4 p.p.m. of vanillic acid. These results proved the antioxidative effects of active acetone and vanillic acid at low concentrations and their potent use as a stimulator for tomato germination and growth.
-
Maghraby, Hassan Ali,Agameya, Abdel Fattah Mohamed,Swelam, Manal Shafik,El Dabah, Nermeen Ahmed,Ahmed, Ola Youssef The Korean Society for Reproductive Medicine 2022 Clinical and Experimental Reproductive Medicine Vol.49 No.2
Objective: This study investigated the impact of two stimulation protocols using highly purified human menopausal gonadotropin (HP-hMG) on the endocrine profile, follicular fluid soluble Fas levels, and outcomes of intracytoplasmic sperm injection (ICSI) cycles. Methods: This prospective clinical trial included 100 normal-responder women undergoing ovarian stimulation for ICSI; 55 patients received concomitant follicle-stimulating hormone (FSH) plus HP-hMG from the start of stimulation, while 45 patients received FSH followed by HP-hMG during mid/late follicular stimulation. The primary outcome was the number of top-quality embryos. The secondary outcomes were the number and percentage of metaphase II (MII) oocytes and the clinical pregnancy rate. Results: The number of MII oocytes was significantly higher in the concomitant protocol (median, 13.0; interquartile range [IQR], 8.5-18.0 vs. 9.0 [8.0-13.0] in the consecutive protocol; p=0.009); however, the percentage of MII oocytes and the fertilization rate were significantly higher in the consecutive protocol (median, 90.91; IQR, 80.0-100.0 vs. 83.33 [75.0-93.8]; p=0.034 and median, 86.67; IQR, 76.9-100.0 vs. 77.78 [66.7-89.9]; p=0.028, respectively). No significant between-group differences were found in top-quality embryos (p=0.693) or the clinical pregnancy rate (65.9% vs. 61.8% in the consecutive vs. concomitant protocol, respectively). The median follicular fluid soluble Fas antigen level was significantly higher in the concomitant protocol (9,731.0 pg/mL; IQR, 6,004.5-10,807.6 vs. 6,350.2 pg/mL; IQR, 4,382.4-9,418.4; p=0.021). Conclusion: Personalized controlled ovarian stimulation using HP-hMG during the late follicular phase led to a significantly lower response, but did not affect the quality of ICSI.
-
Rehab M. Hamdy,Shaimaa A Habib,Layla A Mohamed,Ola H. Abd Elaziz 한국심초음파학회 2022 Journal of Cardiovascular Imaging (J Cardiovasc Im Vol.30 No.4
BACKGROUND: In many cardiovascular disorders, the contractile performance of the right ventricle (RV) is the primary determinant of prognosis. For evaluating RV volumes and function, 4 dimensional (4D)-echocardiography has become common. This research used 2D and 4D modalities to assess RV contractile performance in hypertensive patients. METHODS: A total of 150 patients with essential hypertension were enrolled in this study, along with 75 age and sex-matched volunteers. Clinical evaluation and echocardiographic examination (including M-mode, tissue Doppler imaging, and 2D speckle tracking) were conducted on all participants. RV volumes, 4D-ejection fraction (EF), 4D-fractional area change (FAC), 4D-tricuspid annular plane systolic excursion (TAPSE), 4D-septal and free wall (FW) strain were all measured using 4D-echocardiography. RESULTS: Hypertensive patients showed 2D-RV systolic and diastolic dysfunction (including TAPSE, 2D-right ventricular global longitudinal strain, RV-myocardial performance index and average E/EaRV) and 4D-RV impairment (including right ventricular EF, FAC, RV strain and TAPSE, right ventricular end-diastolic volume and right ventricular end-systolic volume) compared to the control group. We verified the prevalence of RV systolic dysfunction in hypertension patients using the following parameters: 1) 15% of them had 2D-TAPSE < 17 mm vs. 40% by 4D-TAPSE; 2) 25% of them had 2D-GLS < 19% vs. 42% by 4D-septal strain and 35% by 4D FW strain; 3) 35% of hypertensive patients had 4D-EF < 45%; and finally; 4) 25% of hypertensive patients had 2D-FAC < 35% compared to 45% by 4D-FAC. CONCLUSIONS: The incidence of RV involvement was greater in 4D than in 2D-modality trans-thoracic echocardiography. We speculated that 4D-echocardiography with 4D-strain imaging would be more beneficial for examining RV morphology and function in hypertensive patients than 2D-echocardiography, since 4D-echocardiography could estimate RV volumes and function without making geometric assumptions.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
