Muhammad Mahadi Abdul Jamil

Imaging of the cell surface interface using objective coupled widefield surface plasmon microscopy

We report on the development and on the first use of the widefield surface plasmon (WSPR) microscope in the examination of the cell surface interface at submicron lateral resolutions. The microscope is Kohler illuminated and uses either a 1.45 numerical aperture (NA) oil immersion lens, or a 1.65 NA oil immersion lens to excite surface plasmons at the interface between a thin gold layer and a glass or sapphire cover slip. Like all surface plasmon microscope systems the WSPR has been proven in previous studies to also be capable of nanometric z-scale resolutions. In this study we used the system to image the interface between HaCaT cells and the gold layer. Imaging was performed in air using fixed samples and the 1.45 NA objective based system and also using live cells in culture media using the 1.65 NA based system. Imaging in air enabled the visualisation of high resolution and high-contrast submicron features identified by vinculin immunostaining as component of focal contacts and focal adhesions. In comparison, imaging in fluid enabled cell surface interfacial interactions to be tracked by time-lapse video WSPR microscopy. Our results indicate that the cell surface interface and thus cell signalling mechanisms may be readily interrogated in live cells without the use of labelling techniques.

Fundamental study on brain signal for BCI-FES system development

Electroencephalographic measurements are commonly used in medical and research areas. This article presents an introduction into Electroencephalography (EEG) measurement and the simple experiment of EEG. Its purpose is to develop orientation in EEG field and with building basic knowledge for performing EEG recordings. The normal person used as subject was used in this experiment. It is conducted in three condition; relax, hand grasp and lastly grasp and release. At the end of the experiment, there are some changes of the brain signal due to the activity that subject has been done. It shows that the brain will generate the different signal relate to the activity or the way of thinking of the subject. This study will be used as a fundamental concept for Brain Computer Interface (BCI)-Functional Electrical Stimulation (FES) system development.

Salinity induced changes in cell membrane stability, protein and RNA contents

Seedlings of sugar beet ( Beta vulgarus L.) were used at salinity levels of 0 (control), 4.7, 9.4 and 14.1 dS m-1 to determine the effect of salt on vegetative growth, relative water content, cell membrane stability, protein and RNA contents in sand culture experiment. Fresh and dry weights of plants, shoots and roots decreased significantly with increasing salt concentration. Salinity significantly reduced leaf area and relative water content while cell membrane injury increased with increasing salt concentration. Leaf protein content decreased significantly and sodium dodecyl sulphate-polyacrylamide gel electrophresis (SDS-PAGE) analysis showed significant change in protein profiles in salt treated samples, which suggests that NaCl altered protein pattern. Salinity induced RNA degradation with increasing salt level. Cell membrane stability exhibited negative correlation with fresh and dry weight, leaf area, leaf water content and total protein content. There was also a significant positive correlation between cell membrane injury and RNA degradation. Key words : Salt stress, membrane injury, growth, RWC, protein activity, RNA, Beta vulgarus L.

Development of wireless-based low-cost current controlled stimulator for patients with spinal cord injuries

A spinal cord injury (SCI) has a severe impact on human life in general as well as on the physical status and condition. The use of electrical signals to restore the function of paralyzed muscles is called functional electrical stimulation (FES). FES is a promising way to restore mobility to SCI by applying low-level electrical current to the paralyzed muscles so as to enhance that persons ability to function and live independently. However, due to the limited number of commercially available FES assisted exerciser systems and their rather high cost, the conventional devices are unaffordable for most peoples. It also inconvenient because of wired based system that creates a limitation in performing exercise. Thus, this project is concerned with the development of low-cost current controlled stimulator mainly for the paraplegic subjects. The developed device should be based on a microcontroller, wireless based system using Zigbee module, voltage-to-current converter circuit and should produce proper monophasic and biphasic current pulses, pulse trains, arbitrary current waveforms, and a trigger output for FES applications. The performances of the device will be assessed through simulation study and validated through experimental work. This device will be developed as in the new technique of the stimulator development with low cost and one of the contributing factors in Rehabilitation Engineering for patients with SCI.

Study of effect of microsecond pulsed electric fields on threshold area of HeLa cells

Microsecond pulse electric field (μsPEF) application development substantially affected the development of research process including controlling cell functions by using pulses of electrical fields to create pores through a cellular membrane causes cell lysis and apoptosis commonly known as electroporation. Here we demonstrate the influence of the μsPEF on the threshold area (TA) of human cervical cancer cells (HeLa) membrane. The electric field for μsPEF is 3 kV/cm while the pulse interval is 100 ms. The pulse length and the number of pulses were fixed at 10 μs and 5, respectively. While the cultured skin cells are placed in 9 mm-gap EP electrode chamber for allowing real time observation of membrane permeability changes and cellular physiology. In order to initiate higher cell viability rate, high transfection efficiency, lower sample contamination and smaller Joule heating effect the modification of EP chamber need to be done which can be controlled by pH scale, temperature and humidity. The experiment using high pulse electrical field with simply repetitive pulses shows the threshold area of cell membrane was decreasing gradually to 44.59 μm, and is settled within hundreds of second. We found that the threshold area of cells membrane was affected when exposed to high voltage pulse electric field. The dependence of the threshold area on the HeLa cell membrane might be associated with the electrical impedance of the plasma membrane that begins to fluctuate after the application of a certain level of μsPEF.

Widefield Surface Plasmon Resonance Microscope: A Novel Biosensor Study of Cell Attachment to Micropatterned Substrates

In this study, Human adult, low Ca2+, high Temperature (HaCaTs) Keratinocytes were cultured on microcontact printed fibronectin repeat gratings of 1.8, 3.8, 5, 12.5 and 25µm for 24 hours. The cells were then fixed with 0.1% Glutaraldehyde and dehydrated in serial alcohol [1]. The alignment of the cells were then measured, where 0° represents 100% alignment to the pattern, in order to identify those features that promoted the highest degree of cell alignment. From the quantitative analysis it became clear that HaCaTs cells align most readily to the 12.5µm pattern. A 12.5µm stamp was therefore used to stamp pattern fibronectin on to prefabricated Au/Cr/glass surface plasmon substrates. HaCaTs cells were cultured on the substrates for 24 hours and imaged with the “Widefield Surface Plasmon Resonance” (WSPR) microscope

An Investigation into Printing Processes and Feasibility Study for RFID Tag Antennas

This paper will explain a study of several printing process (screen printing, flexography, gravure and ink jet printing) for RFID antennas transponder. The potential of each process will also be investigated. A current sample of RFID is selected, and the antenna processes have been identified, and the comparison of antenna read range will be exhibited.

Current source with low voltage controlled for surface Electrical Stimulation

Functional Electrical Stimulation (FES) is a promising way to restore mobility to Spinal Cord Injury (SCI) patients by applying low-level electrical current to the paralyzed muscles so as to enhance that persons ability to function and live independently. However, due to the limited number of commercially available FES assisted exerciser systems and their rather high cost, the conventional devices are unaffordable for most peoples. Thus, this paper makes a comparative study of the various design of a multiple purpose portable functional electrical stimulator which is used in surface stimulation for patients with spinal cord injuries. The functionality, circuit performance and reliability of the circuits are presented.

Exploitation of accelerometer for rehabilitation process

This paper proposes a post-stroke rehabilitation system for hemiparetic-arm based on the application of accelerometer. The study focuses on designing, developing and simulating the results. The result is recordable and stored for post-processing and progressive status tracking. The subject needs to wear a set of sensors over the wrist while performing a few basics arm movement. Nevertheless, the sensor may also be worn to other body parts. In order to achieve the goal, the use accelerometer for rehabilitation is introduced. The data will be carried out to a computer where it will be converted into series of readable data. The experiment demonstrates the capabilities of the sensors to produce extended information regarding arm movement activities. It is believed that the system offers more information than conventional method and also the ability to improve training quality, results and patients progress. For initial proof of concept, the system will be tested to a healthy normal subject.

Integration of tilt sensors as a device for monitoring rehabilitation process

This paper proposes a post-stroke rehabilitation system for hemiparetic-arm based on the application of tilt sensors. The study focuses on designing, developing and simulating the results. The result is documented for the purpose of post-processing and progressive status tracking. The subject needs to wear a set of sensors over the palm while performing a few basics arm movement. The data will be converted into series of readable data and will be displayed on android based smart phone. The experiment demonstrates the capabilities of the sensors to produce extended information regarding hand movement activities. It is believed that the system offers more information than conventional method and also the ability to improve training quality, results and patients progress. For initial proof of concept, the system will be tested to a healthy normal subject.