Low-Voltage CMOS Current Feedback Operational Amplifier and Its Application

Soliman A. Mahmoud,Ahmed H. Madian,Ahmed M. Soliman 한국전자통신연구원 2007 ETRI Journal Vol.29 No.2

A novel low-voltage CMOS current feedback operational amplifier (CFOA) is presented. This realization nearly allows rail-to-rail input/output operations. Also, it provides high driving current capabilities. The CFOA operates at supply voltages of ±0.75 V with a total standby current of 304 μA. The circuit exhibits a bandwidth better than 120 MHz and a current drive capability of ±1 mA. An application of the CFOA to realize a new all-pass filter is given. PSpice simulation results using 0.25 μm CMOS technology parameters for the proposed CFOA and its application are given.

Peritoneal cancer index as a predictor of survival in advanced stage serous epithelial ovarian cancer: a prospective study

Alaa A. Elzarkaa,Waleed Shaalan,Doaa Elemam,Hassan Mansour,Mahmoud Melis,Eduard Malik,Amr A. Soliman 대한부인종양학회 2018 Journal of Gynecologic Oncology Vol.29 No.4

OBJECTIVE: A numerical score, the peritoneal cancer index (PCI), was developed to reflect the extent of tumor growth in gastric and colorectal cancers and to tailor treatment. This study aimed to examine the value of the PCI score in advanced epithelial ovarian cancer (EOC) regarding completeness of surgical cytoreduction and survival. METHODS: This was a prospective observational cohort study. Patients with primary serous EOC at International Federation of Gynecology and Obstetrics (FIGO) stages IIIB or higher were included. Patients with FIGO stage IVB as well as those assigned to receive neoadjuvant treatment were excluded from the study. The PCI was obtained and registered intraoperatively. RESULTS: In the study period we recruited 96 patients with serous EOC stage IIIB-IVA. A PCI score cut-off value of 13 was calculated using a receiver operator characteristic (ROC) curve, above which worse survival is expected (area under the curve [AUC]=0.641; 95% confidence interval [CI]=0.517-0.765; sensitivity and specificity 80.6%, 45.0%, respectively; p=0.050). A multivariate analysis determined that suboptimal surgical cytoreduction was the only independent predictive factor for recurrence (odds ratio [OR]=7.548; 95% CI=1.473-38.675; p=0.015). A multivariate analysis determined that only suboptimal surgical cytoreduction (hazard ratio [HR]=2.33; 95% CI=0.616-8.795; p=0.005), but not PCI score >13 (HR=1.289; 95% CI=0.329-5.046; p=0.716), was an independent predictive factor for death. CONCLUSION: We conclude from this study that the PCI score is a reliable tool helping to assess the extent of disease in advanced serous EOC patients and may help predicting complete surgical cytoreduction but cannot qualify as a predictor of survival.

New CMOS Fully Differential Transconductor and Application to a Fully Differential Gm-C Filter

Mohamed Omran Shaker,Soliman A Mahmoud,Ahmed M Soliman 한국전자통신연구원 2006 ETRI Journal Vol.28 No.2

A new CMOS voltage-controlled fully-differential transconductor is presented. The basic structure of the proposed transconductor is based on a four-MOS transistor cell operating in the triode or saturation region. It achieves a high linearity range of ± 1 V at a 1.5 V supply voltage. The proposed transconductor is used to realize a new fully-differential Gm-C low-pass filter with a minimum number of transconductors and grounded capacitors. PSpice simulation results for the transconductor circuit and its filter application indicating the linearity range and verifying the analytical results using 0.35 μm technology are also given.

Field programmable analog arrays for implementation of generalized nth-order operational transconductance amplifier-C elliptic filters

Diab, Maha S.,Mahmoud, Soliman A. Electronics and Telecommunications Research Instit 2020 ETRI Journal Vol.42 No.4

This study presents a new architecture for a field programmable analog array (FPAA) for use in low-frequency applications, and a generalized circuit realization method for the implementation of nth-order elliptic filters. The proposed designs of both the FPAA and elliptic filters are based on the operational transconductance amplifier (OTA) used in implementing OTA-C filters for biopotential signal processing. The proposed FPAA architecture has a flexible, expandable structure with direct connections between configurable analog blocks (CABs) that eliminates the use of switches. The generalized elliptic filter circuit realization provides a simplified, direct synthetic method for an OTA-C symmetric balanced structure for even/odd-nth-order low-pass filters (LPFs) and notch filters with minimum number of components, using grounded capacitors. The filters are mapped on the FPAA, and both architectures are validated with simulations in LTspice using 90-nm complementary metal-oxide semiconductor (CMOS) technology. Both proposed FPAA and filters generalized synthetic method achieve simple, flexible, low-power designs for implementation of biopotential signal processing systems.

Effect of Patient Empowerment Model on Smoking Cessation: Randomized Controlled Trial

Ghada M. Khafagy,Mervat M. Mahmoud,Saeed S. A. Soliman 대한가정의학회 2021 Korean Journal of Family Medicine Vol.42 No.5

Background: Smoking is a preventable cause of chronic morbidity. Patient empowerment is a process through which people establish greater control over their health-related decisions and actions. To assess the effect of patient empowerment versus health education on the nicotine dependence score and progress of patients under different stages of smoking cessation. Methods: This was a single-blinded randomized controlled clinical trial that included 76 smokers attending family medicine clinics. Participants were divided into two groups: empowerment and health education groups. Their nicotine-dependence score and smoking cessation stage were identified. All study participants were subjected to five health education sessions with a 3-month follow-up period. Results: The mean nicotine-dependence score decreased significantly in both groups after the intervention. This decrease was slightly higher in the empowerment group; however, the difference was not statistically significant. After the intervention, 16.7% of the health education and 30.0% of the empowerment group transitioned from stage 1 to stages 2–4 of smoking cessation, with the change being statistically significant only in the empowerment group. There was no statistically significant difference in the number of study participants who stopped smoking between the health education and empowerment groups. Conclusion: Both the empowerment model and traditional health education have similar positive effects on decreasing the nicotine-dependence level. There was a significant improvement in the stage of change for patients under the empowerment model, although there was no statistically significant difference between the groups regarding the number of participants who stopped smoking.

Novel nomogram-based integrated gonadotropin therapy individualization in in vitro fertilization/intracytoplasmic sperm injection: A modeling approach

Abdel Hameed I M Ebid,Sara M Abdel Motaleb,Mahmoud I Mostafa,Mahmoud M A Soliman 대한생식의학회 2021 Clinical and Experimental Reproductive Medicine Vol.48 No.2

Objective: This study aimed to characterize a validated model for predicting oocyte retrieval in controlled ovarian stimulation (COS) and to construct model-based nomograms for assistance in clinical decision-making regarding the gonadotropin protocol and dose.Methods: This observational, retrospective, cohort study included 636 women with primary unexplained infertility and a normal menstrual cycle who were attempting assisted reproductive therapy for the first time. The enrolled women were split into an index group (n=497) for model building and a validation group (n=139). The primary outcome was absolute oocyte count. The dose-response relationship was tested using modified Poisson, negative binomial, hybrid Poisson-Emax, and linear models. The validation group was similarly analyzed, and its results were compared to that of the index group. Results: The Poisson model with the log-link function demonstrated superior predictive performance and precision (Akaike information criterion, 2,704; λ=8.27; relative standard error (λ)=2.02%). The covariate analysis included women’s age (p<0.001), antral follicle count (p<0.001), basal follicle-stimulating hormone level (p<0.001), gonadotropin dose (p=0.042), and protocol type (p=0.002 and p<0.001 for short and antagonist protocols, respectively). The estimates from 500 bootstrap samples were close to those of the original model. The validation group (n=139) showed model assessment metrics comparable to the index model. Based on the fitted model, a static nomogram was built to improve visualization. In addition, a dynamic electronic tool was created for convenience of use.Conclusion: Based on our validated model, nomograms were constructed to help clinicians individualize the stimulation protocol and gonadotropin doses in COS cycles.

Towards the production of monodisperse gelatin nanoparticles by modified one step desolvation technique

Khaled S. Shamarekh,Heba A. Gad,Mahmoud E. Soliman,Omaima A. Sammour 한국약제학회 2020 Journal of Pharmaceutical Investigation Vol.50 No.2

Purpose The aim of the present study was to prepare gelatin nanoparticles (GNPs) using modified one step desolvation method to obtain small, uniformly sized, and spherical GNPs. Methods The modifications involved the preparation of high molecular weight gelatin (HMWG) by fractionation of gelatin. HMWG was freeze-dried to be used in a specified concentration for preparation of GNPs with controllable properties. Furthermore, HMWG was cationized by dissolving it in acidified deionized water at pH value less than its isoelectric point. Factorial design analysis was utilized to investigate the effect of different preparation variables (viz. HMWG concentration, pH and ratio of HMWG solution volume to non-solvent volume) on particle size, polydispersity index (PDI), zeta potential and yield of GNPs. Results Results revealed the formation of monodisperse GNPs with small particle size, low PDI values (< 0.2) and high yield. FT-IR spectroscopy and differential scanning calorimetry studies revealed that the conformational structure of HMWG chains was altered within GNPs matrices. Conclusion The suggested modifications introduced on the one-step desolvation method enable to prepare successfully monodispersed GNPs with narrow size distribution and high particle yield.

EXPLORING SCARCITY IN MOBILE PROMOTION AND IMMEDIATE PURCHASE INTENTION

Qin Sun,Rajasree K. Rajamma,Deborah D. Heisley,Mahmoud A Soliman 글로벌지식마케팅경영학회 2020 Global Marketing Conference Vol.2020 No.11