Optoelectronic stimulation of the brain using carbon nanotubes.

Mohy-Ud-Din, Zia,Woo, Sang Hyo,Kim, Jee Hyun,Cho, Jin Ho Pergamon Press [etc.] 2010 Annals of biomedical engineering Vol.38 No.11

<P>This paper presents the simulation results of a novel technique to stimulate the brain using a carbon nanotubes (CNT) based optically activated stimulator. This technique could be a promising alternative solution to overcome the limitations occurring in the conventional electrical stimulation of the brain and the newly developed opto-genetic stimulation. In this technique, the CNT stimulator, which generated an electrical current when exposed to light, was implanted in the brain. This current stimulated the nearby neurons to generate an action potential. The simulation results illustrated that a single-wall carbon nanotube of 50 nm2 size could stimulate a 40 μm2 area of the brain, whereas a multiwall carbon nanotube could cover a 12 μm2 area of the brain. Additionally, simulations were also performed to determine the optimal shape and appropriate coating material for commercial optical stimulators to maximize the stimulation efficacy in the brain.</P>

Effectiveness of dredging and drains’ treatment on water quality of Rosetta branch

Mohie Eldin M. Omar,Mohamed A. Ghareeb,Shaimaa El Sherbini 대한환경공학회 2022 Environmental Engineering Research Vol.27 No.1

Rosetta Branch of Nile River in Egypt receives drainage water from five agricultural drains deteriorating its water quality. Since the branch is used for irrigation and municipal purposes, its water quality should be enhanced. Hence, the current paper aimed at providing the most effective intervention to improve the branch water quality. Preventing drainage disposal was excluded due its significance to downstream users. The paper investigated the impacts of drains" treatment and branch dredging on hydrodynamics and water quality. The branch was numerically simulated using HECRAS model, and calibrated using measured water levels and quality parameters. The paper selected constructed wetlands as the most suitable method for drainage treatment based on conditions of study area. SUBWET model predicted optimal designs of wetlands achieving the desired treatment efficiency. SUBWET model was calibrated with experimental wetlands at Delta Barrage. Results showed that 1-m dredging dropped water surface elevations by 22 to 50 cm. Dredging had no significant changes in the backwater zone of Edfina Barrage at the branch end except for the maximum flow case. Simulation of dissolved oxygen and ammonium showed that dredging and treatment improved water quality. Drains’ treatment by constructed wetlands with selected designs was much more effective than dredging.

Polysomnography by ECG Telemetry System

Mohy-Ud-Din Zia,Woo Sanghyo,Changwook Kim,Junghyun Lee,Jangwoo Lee,Heejoon Park,Chulho Won,Euisung Chung,J. H. Cho 대한전자공학회 2007 ITC-CSCC :International Technical Conference on Ci Vol.2007 No.7

Recently, the biotelemetry is become more and more popular and people and trying to get the maximum beneficent from it. In this regard we developed real ECG telemetry system have extremely low power consumption and the dimensions are 2.5 ㎝ by 3 ㎝. In this circuit ECG amplifier and transmitter are embedded on the single side PCB. This paper explain the method to use the 2-lead ECG signal in the recording of the dream time of a normal person by detecting the REM sleep time through the heart rate variability in sleep cycle to make the sleep studies easier and also a person can record his dream time in the home. In this way we are able to use the biotelemetry in the recording of the dream time remotely. This method is much easier than the conventional method of Polysomnography.

Effect of nitrogen doping and hydrogen confinement on the electronic properties of a single walled carbon nanotube

Bashir Mohi Ud Din Bhat,Jehangir Rashid Dar,Pratima Sen 한국탄소학회 2016 Carbon Letters Vol.17 No.-

This paper addresses the effect of dopants on the electronic properties of zigzag (8, 0) semiconducting single walled carbon nanotubes (SWCNTs), using extended H?ckel theory combined with nonequilibrium Green’s function formalism. Through appropriate dopant concentrations, the electronic properties of SWCNTs can be modified. Within this context, we present our ongoing investigation on (8, 0) SWCNTs doped with nitrogen. Quantum confinement effects on the electronic properties of the SWCNTs have also been investigated. The obtained results reveal that the electronic properties of SWCNTs are strongly dependent on the dopant concentration and modification of electronic structures by hydrogen confinement.

GTPBP4 Copy Number Segments as a Predictor of Overall and Disease-Specific Survival of Hepatocellular Carcinoma

( Khaled Mohy Ismaeil ) 대한간학회 2021 춘·추계 학술대회 (KASL) Vol.2021 No.1

HEN Simulation of a Controlled Fluid Flow-Based Neural Cooling Probe Used for the Treatment of Focal and Spontaneous Epilepsy

( Zia Mohy Ud Din ),( Sang Hyo Woo ),( Wei Qun ),( Jee Hyum Kim ),( Jin Ho Cho ) 한국센서학회 2011 센서학회지 Vol.20 No.1

Brain disorders such as epilepsy is a condition that affects an estimated 2.7 million Americans, 50,000,000 worldwide, approximately 200,000 new cases of epilepsy are diagnosed each year. Of the major chronic medical conditions, epilepsy is among the least understood. Scientists are conducting research to determine appropriate treatments, such as the use of drugs, vagus nerve stimulation, brain stimulation, and Peltier chip-based focal cooling. However, brain stimulation and Peltier chip-based stimulation processes cannot effectively stop seizures. This paper presents simulation of a novel heat enchanger network(HEN) technique designed to stop seizures by using a neural cooling probe to stop focal and spontaneous seizures by cooling the brain. The designed probe was composed of a U-shaped tube through which cold fluid flowed in order to reduce the temperature of the brain. The simulation results demonstrated that the neural probe could cool a 7 mm2 area of the brain when the fluid was flowing atb a velocity of 0.55 m/s. It also showed that the neural cooling probe required 23 % less energy to produce cooling when compared to the Peltier chip-based cooling system.

CFRP strengthening of continuous RC T-beams at hogging moment zone across the flange

Mohammad Mohie Eldin,Ahmed M. Tarabia,Rahma F. Hasson 국제구조공학회 2017 Structural Engineering and Mechanics, An Int'l Jou Vol.64 No.6

Carbon Fiber Reinforced Polymer (CFRP) laminates are used widely either for repairing or strengthening of existing structures. When CFRP laminates are used for strengthening of RC continuous T-beams in the Hogging Moment Zone (HMZ); above and around the intermediate supports, it is important to study the expected positions of the laminates across the width of the beam flange. Although, it is traditional to consider CFRP laminates added above the beam web, this is not practical since walls and columns are located in such positions in general. This paper examines the effect of changing the positions of CFRP laminates used for the strengthening of the hogging moment zone across the beam flange of two-span-T-section beams. The Finite Element (FE) Package ANSYS is used to create 3-D theoretical models needed for the study. It can be concluded that changing the position of CFRP strengthening across the beam flange, in the hogging moment zone, is effective upon the overall behavior. The best locations are either above the web or at the flange just beside the web, due to the presence of walls and/or columns.

Epidural Fibrosis after Lumbar Disc Surgery: Prevention and Outcome Evaluation

Mohamed M. Mohi Eldin,Naglaa M. Abdel Razek 대한척추외과학회 2015 Asian Spine Journal Vol.9 No.3

Study Design: This is a prospective, randomized, controlled study designed and conducted over 10 years from 2002 to 2012. Purpose: The study aimed to monitor the effect of suction drains (SD) on the incidence of epidural fibrosis (EF) and to test, if the use of SD alone, SD with local steroids application, SD combined with fat grafts and local steroids application, or SD combined with fat grafts and without local steroids application, would improve outcome. Overview of Literature: EF contributes to significant unsatisfactory failed-back syndrome. Efforts have been tried to reduce postoperative EF, but none were ideal. Methods: Between September 2002 and 2012, 290 patients with symptomatic unilateral or bilateral, single-level lumbar disc herniation were included in the study. Two groups were included, with 165 patients in group I (intervention group) and 125 patients in group II (control group). Group I was subdivided into four subgroups: group Ia (SD alone), group Ib (SD+fat graft), group Ic (SD+local steroids), and group Id (SD+fat graft+local steroids). Results: The use of SD alone or combined with only fat grafts, fats grafts and local steroids application, or only local steroids application significantly improved patient outcome and significantly reduced EF as measured by magnetic resonance imaging (MRI). Conclusions: This study has clearly demonstrated the fact that the use of suction drainage alone or combined with only fat grafts, fats grafts and local steroids application, or only local steroids application significantly improved patient outcome with respect to pain relief and functional outcome and significantly reduced EF as measured by an MRI. A simple grading system of EF on MRI was described.

Lumbar Transpedicular Implant Failure: A Clinical and Surgical Challenge and Its Radiological Assessment

Mohamed M. Mohi Eldin,Abdel Mohsen Arafa Ali 대한척추외과학회 2014 Asian Spine Journal Vol.8 No.3

multicenter, controlled case study review of a big scale of pedicle-screw procedures from January 2000 to June 2010. The outcomes were compared to those with no implant failure. Purpose: The purpose of this study was to review retrospectively the outcome of 100 patients with implant failure in comparison to 100 control-patients, and to study the causes of failure and its prevention. Overview of Literature: Transpedicular fixation is associated with risks of hardware failure, such as screw/rod breakage and/or loosening at the screw-rod interface and difficulties in the system assembly, which remain a significant clinical problem. Removal or revision of the spinal hardware is often required. Methods: Two hundred patients (88 women, 112 men) were divided into 2 major groups, with 100 patients in group I (implant failure group G1) and 100 patients in group II (successful fusion, control group G2). We subdivided the study groups into two subgroups: subgroup a (single-level instrumented group) and subgroup b (multilevel instrumented group). The implant status was assessed based on intraoperative and follow-up radiographs. Results: Implant failure in general was present in 36% in G1a, and in 64% in G1b, and types of implant failure included screw fracture (34%), rod fracture (24%), rod loosening (22%), screw loosening (16%), and failure of both rod and screw (4%). Most of the failures (90%) occurred within 6 months after surgery, with no reported cases 1 year postoperatively. Conclusions: We tried to address the problem and study the causes of failure, and proposed solutions for its prevention.

Cervical Pedicle Screw Fixation: Anatomic Feasibility of Pedicle Morphology and Radiologic Evaluation of the Anatomical Measurements

Mohamed M. Mohi Eldin 대한척추외과학회 2014 Asian Spine Journal Vol.8 No.3

Study Design: All parameters were measured manually and with a computed tomography (CT) scanner. For the manual measurements, a Vernier scale instrument was used. Purpose: This study evaluates quantitatively pedicles of middle and lower cervical spine (C3 to C7) and to evaluate the possibilities of using these structures as anchors in posterior cervical fusion. Overview of literature: Pedicle screws may be an alternative fixation technique for posterior cervical instrumentation. Methods: Twenty-two bony sets of adult cervical spines were studied (110 vertebrae, 220 pedicles) from C3 down to C7. Results: CT measurement of cervical pedicles appeared to be accurate and valuable for preoperative planning of cervical pedicle screw instrumentation. The study showed a high correlation between the values obtained by manual and CT measurements of pedicle dimensions. The technical challenge of insertion is the obvious theoretical drawback of the use of cervical pedicle screws. Many technical factors are important to consider, namely, the point of screw entry, the pedicle dimensions, the screw direction according to the pedicle angle and orientation, the screw diameter and length, and the method of screw introduction. Conclusions: Transpedicular screw fixation of the cervical spine appears to be promising. Anatomic limitations should be clear to the surgeon. Further clinical and biomechanical studies are needed to settle this technique.