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Medical physics aspects of Intensity-Modulated Radiotherapy practice in Malaysia

Hizam NDA, Ung NM, Jong WL, Zin HM, Rahman ATA, Loh JPY, et al.

Phys Med, 2019 Nov;67:34-39.
PMID: 31655398 DOI: 10.1016/j.ejmp.2019.10.023

PURPOSE: Intensity Modulated Radiotherapy (IMRT) has changed the practice of radiotherapy since its implementation in the 1990s. The purpose of this study is to review current practice of IMRT in Malaysia.
METHODS: A survey on medical physics aspects of IMRT is conducted on radiotherapy departments across Malaysia to assess the usage, experience and QA in IMRT, which is done for the first time in this country. A set of questionnaires was designed and sent to the physicist in charge for their responses. The questionnaire consisted of four sections; (i) Experience and qualification of medical physicists, (ii) CT simulation techniques (iii) Treatment planning and treatment unit, (iv) IMRT process, delivery and QA procedure.
RESULTS: A total of 26 responses were collected, representing 26 departments out of 33 radiotherapy departments in operation across Malaysia (79% response rate). Results showed that the medical physics aspects of IMRT practice in Malaysia are homogenous, with some variations in certain areas of practices. Thirteen centres (52%) performed measurement-based QA using 2D array detector and analysed using gamma index criteria of 3%, 3 mm with variation confidence range. In relation to the IMRT delivery, 44% of Malaysia's physicist takes more than 8 h to plan a head and neck case compared to the UK study possibly due to the lack of professional training.
CONCLUSIONS: This survey provides a picture of medical physics aspects of IMRT in Malaysia where the results/data can be used by radiotherapy departments to benchmark their local policies and practice.

Matched MeSH terms: Physics*
22nd International Conference on Medical Physics 2016, Bangkok, Thailand; Medical physics propelling global health

Tsapaki V, Ibbott G, Krisanachinda A, Ng KH, Suh TS, Tabakov S, et al.

Phys Med, 2017 Dec;44:196-198.
PMID: 29221890 DOI: 10.1016/j.ejmp.2017.11.022

As medical technology evolves and patient needs increase, the need for well-trained and highly professional medical physicists (MPs) becomes even more urgent. The roles and responsibilities of MPs in various departments within the hospital are diverse and demanding. It is obvious that training, continuing education and professional development of MPs have become essential. One of the ways for an MP to advance his or her knowledge is to participate in conferences and congresses. Last year, the 22nd International Conference of Medical Physics (ICMP 2016) took place in Bangkok, Thailand. The event attracted 584 delegates with most of the participants coming from Asia. It attracted also delegates from 42 countries. The largest delegations were from Thailand, Japan and South Korea. ICMP 2016 included 367 oral presentations and e-posters, most of these being in the fields of Radiation Therapy, Medical Imaging and Radiation Safety. All abstracts were published as an e-book of Abstracts in a supplement to the official IOMP Journal. Many companies had exhibition stands at ICMP2016, thus allowing the participants to see the latest developments in the medical physics-related industry. The conference included 42 mini-symposia, part of the first "IOMP School" activity, covering various topics of importance for the profession and this special issue follows from the success of the conference.

Matched MeSH terms: Physics*
Fulltext Impacts of gold nanoparticles on MHD mixed convection Poiseuille flow of nanofluid passing through a porous medium in the presence of thermal radiation, thermal diffusion and chemical reaction

Aman S, Khan I, Ismail Z, Salleh MZ

Neural Comput Appl, 2018;30(3):789-797.
PMID: 30100679 DOI: 10.1007/s00521-016-2688-7

Impacts of gold nanoparticles on MHD Poiseuille flow of nanofluid in a porous medium are studied. Mixed convection is induced due to external pressure gradient and buoyancy force. Additional effects of thermal radiation, chemical reaction and thermal diffusion are also considered. Gold nanoparticles of cylindrical shape are considered in kerosene oil taken as conventional base fluid. However, for comparison, four other types of nanoparticles (silver, copper, alumina and magnetite) are also considered. The problem is modeled in terms of partial differential equations with suitable boundary conditions and then computed by perturbation technique. Exact expressions for velocity and temperature are obtained. Graphical results are mapped in order to tackle the physics of the embedded parameters. This study mainly focuses on gold nanoparticles; however, for the sake of comparison, four other types of nanoparticles namely silver, copper, alumina and magnetite are analyzed for the heat transfer rate. The obtained results show that metals have higher rate of heat transfer than metal oxides. Gold nanoparticles have the highest rate of heat transfer followed by alumina and magnetite. Porosity and magnetic field have opposite effects on velocity.

Matched MeSH terms: Physics
Fulltext Conductance modulation of charged lipid bilayer using electrolyte-gated graphene-field effect transistor

Kiani MJ, Harun FK, Ahmadi MT, Rahmani M, Saeidmanesh M, Zare M

Nanoscale Res Lett, 2014;9(1):371.
PMID: 25114659 DOI: 10.1186/1556-276X-9-371

Graphene is an attention-grabbing material in electronics, physics, chemistry, and even biology because of its unique properties such as high surface-area-to-volume ratio. Also, the ability of graphene-based materials to continuously tune charge carriers from holes to electrons makes them promising for biological applications, especially in lipid bilayer-based sensors. Furthermore, changes in charged lipid membrane properties can be electrically detected by a graphene-based electrolyte-gated graphene field effect transistor (GFET). In this paper, a monolayer graphene-based GFET with a focus on the conductance variation caused by membrane electric charges and thickness is studied. Monolayer graphene conductance as an electrical detection platform is suggested for neutral, negative, and positive electric-charged membrane. The electric charge and thickness of the lipid bilayer (Q LP and L LP) as a function of carrier density are proposed, and the control parameters are defined. Finally, the proposed analytical model is compared with experimental data which indicates good overall agreement.

Matched MeSH terms: Physics
Fulltext Electrically Doped Nanoscale Devices Using First-Principle Approach: A Comprehensive Survey

Dey D, De D, Ahmadian A, Ghaemi F, Senu N

Nanoscale Res Lett, 2021 Jan 29;16(1):20.
PMID: 33512575 DOI: 10.1186/s11671-020-03467-x

Doping is the key feature in semiconductor device fabrication. Many strategies have been discovered for controlling doping in the area of semiconductor physics during the past few decades. Electrical doping is a promising strategy that is used for effective tuning of the charge populations, electronic properties, and transmission properties. This doping process reduces the risk of high temperature, contamination of foreign particles. Significant experimental and theoretical efforts are demonstrated to study the characteristics of electrical doping during the past few decades. In this article, we first briefly review the historical roadmap of electrical doping. Secondly, we will discuss electrical doping at the molecular level. Thus, we will review some experimental works at the molecular level along with we review a variety of research works that are performed based on electrical doping. Then we figure out importance of electrical doping and its importance. Furthermore, we describe the methods of electrical doping. Finally, we conclude with a brief comparative study between electrical and conventional doping methods.

Matched MeSH terms: Physics
The World Wide Web is a net disservice to medical physicists in developing countries

Ng KH, Niroomand-Rad A, Hendee WR

Med Phys, 2001 Dec;28(12):2391-3.
PMID: 11797940
Matched MeSH terms: Physics/trends*
Stem cell research - an international medico-religio-legal impasse?

Musa Mohd. Nordin

Malaysian Journal of Paediatrics and Child Health, 2005;14(1):1-4.
MyJurnal

Heralded by the revelation of the double helical structure of the DNA molecule in 1953, the 21st century is aptly designated the biotechnology century. The 20th century of physics, which saw the transformation of silicon into computing magic, was embraced with enthusiasm by virtually every household. However, unlike her predecessor, the same cannot be said about the advancements in biomedicine.

Matched MeSH terms: Physics
Fulltext Solution for nonlinear Duffing oscillator using variable order variable stepsize block method

Ahmad Fadly Nurullah Rasedee, Mohammad Hasan Abdul Sathar, Norizarina Ishak, Irneza Ismail, Musab Sahrim, Nur Ainna Ramli, et al.

MATEMATIKA, 2017;33(2):165-175.
MyJurnal

Real life phenomena found in various fields such as engineering, physics,
biology and communication theory can be modeled as nonlinear higher order ordinary
differential equations, particularly the Duffing oscillator. Analytical solutions for these
differential equations can be time consuming whereas, conventional numerical solutions
may lack accuracy. This research propose a block multistep method integrated with a
variable order step size (VOS) algorithm for solving these Duffing oscillators directly.
The proposed VOS Block method provides an alternative numerical solution by reducing
computational cost (time) but without loss of accuracy. Numerical simulations
are compared with known exact solutions for proof of accuracy and against current
numerical methods for proof of efficiency (steps taken).

Matched MeSH terms: Physics
Fulltext ‘Smartfan’ – An energy saving innovation for workplace

Nur Jannah Azman, Wan Mohd Rizlan Wan Idris, Alice Shanthi

Jurnal Inovasi Malaysia, 2019;2(2):111-122.
MyJurnal

Circular 10/2016 issued by UiTM Vice-Chancellor’s office comprises a clear guideline for 2017 Strategic Budget Planning. The guidelines can help the Head of PTJ’s to plan and take necessary cost effective measures to reduce on utility expenditure especially to counter the rising monthly electricity bills related to the use of air conditioners on campuses. Looking at the figures drawn from the energy management office in UiTM Negeri Sembilan Branch, UiTM Kuala Pilah campus has spent an average of RM153, 028.88 monthly in 2016. As of August 2016, the cost of electricity consumption in UiTM Kuala Pilah has reached RM1,224,231.03. This amount has surpassed the overall approved allocation of RM 800,000.00 for 2016 electricity bill. In order to reduce spending and encourage saving, as well as responding to the ‘Energy Savings Campaign’ held at the campus level, various efforts have been taken at the departmental levels. One of the innovative products that came about from the campaign is the ‘Smartfan’ project pioneered by the Physics and Materials Science Unit. The main objective of this project is the production of a “smartfan” or a mini air conditioner which is a simple, cost-effective and an energy saving device. In addition, products and ideas from the campaign can be piloted and taken to innovative, inventions and design contests at national and international levels.

Matched MeSH terms: Physics
Fulltext A model for online interactive remote education for medical physics using the Internet

Woo MK, Ng KH

J Med Internet Res, 2003 Jan-Mar;5(1):e3.
PMID: 12746208

Medical physics is a relatively small community but it spans great geographical distances, usually with a scarcity of experts whose expertise could greatly benefit students entering into the field. In addition there are many software systems for which an interactive education method would be most advantageous.

Matched MeSH terms: Nuclear Physics/education*; Nuclear Physics/methods
Fulltext Intrastromal corneal foreign body – case series and discussion on the physics of injury

Andrea, B.K., Safinaz, M.K., Umi Kalthum, M.N., Mushawiahti, M.

Journal of Surgical Academia, 2018;8(2):23-26.
MyJurnal

Traumatic injury to the eye can occur due to various causes, most of which are avoidable. Here we report three cases of intrastromal corneal foreign bodies (FB) which required surgical removal. Most corneal FBs are removed easily at the slit lamp, however, these cases required surgical intervention due to the mechanism of which the FB penetrated into the stroma. Although the mechanism of injury was similar, with all three cases occurring at high velocity, we observed that the entry and level of penetration differed in each case. In the first case, the corneal FB penetrated the cornea and was embedded in the anterior stroma, whereas in the second case, the FB was embedded in the posterior stroma, but with an intact endothelium. In the third case, the FB caused a full thickness, self-sealed laceration wound but remained embedded in the stroma. Through further evaluation, we noted that several factors contribute towards the severity of the injury, namely, anatomy of the cornea, area affected, shape, size, mass and velocity of the object. We speak in depth about the mechanism of injury and physics associated with these injuries and why the penetration differed in each case.

Matched MeSH terms: Physics
Fulltext Schrodinger equation in string theory

Anuar Alias, Ithnin Abdul Jalil, Tajuddin, W.A.

Journal of Nuclear and Related Technologies, 2010;2010(2):154-169.
MyJurnal

String theory is currently considered as the leading candidate for a unified theory of physics combining the Standard Model of forces and particles with gravity which is best described by Einstein theory of General Relativity. Contrary to classical model of point particle, String theory proposes that matter, force, even space and time are composed of tiny vibrating strings. This paper is to elaborate on the correspondence between string states and quantum fields by initially constructing general time-dependent states from string basis states analogous to general timedependent super-positions of basis states for a point particle. From this derivation we can show that an equation emerges from the 'classical' Schrodinger equation that represents the Schrodinger equation in String theory. This is very interesting to investigate since the Schrodinger equation is at the core of Quantum Mechanics which is the foundation of Standard Model that is the pillar of Nuclear physics.

Matched MeSH terms: Nuclear Physics; Physics
Fulltext Study of growth in Bi2Sr2CaCu2Oy single crystals

Razak Mohd Ali Lee, Khairul Anwar Mohamad, Katsuyoshi, Hamasaki

Journal of Nuclear and Related Technologies, 2007;2007(1):195-198.
MyJurnal

We put attention on Intrinsic Josephson Junction (IJJ) to study the fundamental physic for device applications. Convenient self-flux method was used to grow BSCCO single crystals. We investigated the lid effect to examine the single crystal growth of high TC (Critical Temperature). We found that for the crystal growth with no lid, two stage transitions of TC ≅ 61 K and 77 K were observed. While for the crystal growth with lid, the BSCCO has TC ≅ 80K, ΔTC = 10K and approximately average size5x2mm 2 . When we increased weight of lid, the single crystal have increased to TC =80K, ΔTC = 4K and the typical size was ≅7x3mm 2 . TC and the crystal growth show a tendency to increase by the effect of the lid. From observed quasi-particle characteristics, c-axis direction changed from semiconductor to intrinsic Josephson characteristic with decreasing temperature.

Matched MeSH terms: Physics
Fulltext Lagrangian formulation of neutrino oscillation

Ong, Jian Fuh, Ithnin Abdul Jalil

Journal of Nuclear and Related Technologies, 2011;2011(1):26-32.
MyJurnal

Neutrino is one of the nuclear particles that are necessary for the correct description of nuclear beta decay. The standard idea is that it is a massless neutral particle and its existence was postulated in order to save the conservation of ener gy principle. This particle was later detected experimentally and it is now known that neutrino has mass. The problem of astrophysical neutrino detection has produced a new phenomenon of neutrino oscillation where the three neutrino flav ours can oscillate between themselves. This paper studies the two component neutrino oscillation problem. We study the neutrino oscillation by using the Lagrangian formulation. In our study, we assume that the neutrinos are produced as n eutrino mass eigenstate and propagate in the vacuum in the superposition of two neutrino flavour state. The Lagrangian for neutrinos with their mass and the oscillation terms were obtained. By using the mass matrix in the Lagrangian, we formulate the time evolution operator in the interaction picture. The neutrino oscillation probability obtained by using the Lagrangian formulation have the same result with the one obtained by using quantum mechanics formulation. This study hopes to gain some deeper understanding into the behaviour of neutrino beyond the Standard Model.

Matched MeSH terms: Physics
Fulltext Identification of Planck's constant by light emitting diodes (LEDS)

Nurain Azmi, Sabirin Mustafa, Nur Hazirah Mohd Yunos, Wan Nor Azlin Wan Mohd Sakri, Muhammad Nazzim Abdul Halim, Amin Aadenan

Journal of Academia Universiti Teknologi MARA Negeri Sembilan, 2020;8(2):33-38.
MyJurnal

In this paper, a simple analysis yet a straight forward method of determining the Planck’s constant by
evaluating the stopping potential of five different colors of light emitting diodes (LEDs) is presented.
The study aimed to identify the Planck’s constant based on the relationship between the potential
difference of LEDs to their respective frequencies under room temperature with low illumination of
ambient light by applying a simple theoretical analysis. The experiment was performed by connecting
the circuit in series connection and the voltage reading of LEDs were recorded and then presented in a
graph of frequency, f versus stopping voltage, Vo. To determine the Planck’s constant, the best fit line
was analyzed and the centroid was also identified in order to find the minimum and maximum errors
due the gradient of the graph. From the analysis, results showed that the Planck constant value was
(5.997 ± 1.520) × 10–34 J.s with approximately 10% of deviation from the actual value. This
demonstrates that a simple analysis can be utilized to determine the Planck’s constant for the purpose
of the laboratory teaching and learning at the undergraduate level and can be served as a starting point
for the students to understand the concept of quantization of energy in Modern Physics more
effectively. This is to further suggest that the Planck’s constant can be identified via a low-cost and
unsophisticated experimental setup.

Matched MeSH terms: Physics
Fulltext Current concepts in cancer research

Ivan Kok Seng Yap, Ammu Kutty Radhakrishnan, Chee Onn Leong

International e-Journal of Science, Medicine & Education, 2013;7(11):19-31.
MyJurnal

Cancer research is an extremely broad topic covering many scientific disciplines including biology (e.g. biochemistry and signal transduction), chemistry (e.g. drug discover and development), physics (e.g. diagnostic devices) and even computer science (e.g. bioinformatics). Some would argue that
cancer research will continue in much the same way as it is by adding further layers of complexity to the scientific knowledge that is already complex and almost beyond measure. But we anticipate that cancer research will undergo a dramatic paradigm shift due to the recent explosion of new discoveries in cancer biology. This review article focuses on the latest horizons in cancer research concerning cancer epigenetics, cancer stem cells, cancer immunology and cancer metabolism.

Matched MeSH terms: Physics
Fulltext Physico-chemical properties of spray-dried red pitaya (Hylocereus polyrhizus) peel powder during storage

Ee, S.C., Bakar, J., Kharidah, M., Dzulkifly, M.H., Noranizan, A.

International Food Research Journal, 2014;21(3):1213-1218.
MyJurnal

The physico-chemical properties of spray-dried pitaya peel powders kept at accelerated (45 ± 2°C) and room temperature (28 ± 2°C) for 14 weeks and 6 months, respectively were evaluated. Changes in physico-chemical properties of the peel powder were used as indicators of stability, while changes of the betacyanin pigment retention was used to calculate the shelf-life of the powder. Storage temperatures significantly (p < 0.05) affected all the studied parameters and Hunter a value had the most significant change. The pigment retention of peel powder was approximately 87% at 45°C and 89% at room temperature storage. Degradation of betacyanin pigment in the powder followed the first order reaction kinetics with the half-life (t1/2) of approximately 76 weeks at 45°C and 38 months at 28°C. The spray-dried pitaya peel powder had a solubility of 87 to 92% and low in powder hygroscopicity. The final Aw of the powder did not exceed 0.6 for both storage temperatures.

Matched MeSH terms: Physics
Comparison of the Newtonian and relativistic predicted trajectories for a low-speed periodically delta-kicked system

Lan BL

Chaos, 2006 Sep;16(3):033107.
PMID: 17014212

The dynamics of a periodically delta-kicked Hamiltonian system moving at low speed (i.e., at speed much less than the speed of light) is studied numerically. In particular, the trajectory of the system predicted by Newtonian mechanics is compared with the trajectory predicted by special relativistic mechanics for the same parameters and initial conditions. We find that the Newtonian trajectory, although close to the relativistic trajectory for some time, eventually disagrees completely with the relativistic trajectory, regardless of the nature (chaotic, nonchaotic) of each trajectory. However, the agreement breaks down very fast if either the Newtonian or relativistic trajectory is chaotic, but very much slower if both the Newtonian and relativistic trajectories are nonchaotic. In the former chaotic case, the difference between the Newtonian and relativistic values for both position and momentum grows, on average, exponentially. In the latter nonchaotic case, the difference grows much slower, for example, linearly on average.

Matched MeSH terms: Physics/methods*
Fulltext The South East Asian Federation of Organizations for Medical Physics (SEAFOMP): Its history and role in the ASEAN countries

Ng Kh, Wong J

Biomed Imaging Interv J, 2008 Apr;4(2):e21.
PMID: 21614324 DOI: 10.2349/biij.4.2.21

Informal discussion started in 1996 and the South East Asian Federation of Organizations for Medical Physics (SEAFOMP) was officially accepted as a regional chapter of the IOMP at the Chicago World Congress in 2000 with five member countries, namely Indonesia, Malaysia, Philippines, Singapore and Thailand. Professor Kwan-Hoong Ng served as the founding president until 2006. Brunei (2002) and Vietnam (2005) joined subsequently. We are very grateful to the founding members of SEAFOMP: Anchali Krisanachinda, Kwan-Hoong Ng, Agnette Peralta, Ratana Pirabul, Djarwani S Soejoko and Toh-Jui Wong.The objectives of SEAFOMP are to promote (i) co-operation and communication between medical physics organizations in the region; (ii) medical physics and related activities in the region; (iii) the advancement in status and standard of practice of the medical physics profession; (iv) to organize and/or sponsor international and regional conferences, meetings or courses; (v) to collaborate or affiliate with other scientific organizations.SEAFOMP has been organizing a series of congresses to promote scientific exchange and mutual support. The South East Asian Congress of Medical Physics (SEACOMP) series was held respectively in Kuala Lumpur (2001), Bangkok (2003), Kuala Lumpur (2004) and Jakarta (2006). The respective congress themes indicated the emphasis and status of development. The number of participants (countries in parentheses) was encouraging: 110 (17), 150 (16), 220 (23) and 126 (7).In honour of the late Professor John Cameron, an eponymous lecture was established. The inaugural John Cameron Lecture was delivered by Professor Willi Kalender in 2004. His lecture was titled "Recent Developments in Volume CT Scanning".

Matched MeSH terms: Physics
Fulltext Real-time teleteaching in medical physics

Woo M, Ng Kh

Biomed Imaging Interv J, 2008 Jan;4(1):e13.
PMID: 21614306 MyJurnal DOI: 10.2349/biij.4.1.e13

Medical physics is a relatively small professional community, usually with a scarcity of expertise that could greatly benefit students entering the field. However, the reach of the profession can span great geographical distances, making the training of students a difficult task. In addition to the requirement of training new students, the evolving field of medical physics, with its many emerging advanced techniques and technologies, could benefit greatly from ongoing continuing education as well as consultation with experts.Many continuing education courses and workshops are constantly being offered, including many web-based study courses and virtual libraries. However, one mode of education and communication that has not been widely used is the real-time interactive process. Video-based conferencing systems do exist, but these usually require a substantial amount of effort and cost to set up.The authors have been working on promoting the ever-expanding capability of the Internet to facilitate the education of medical physics to students entering the field. A pilot project has been carried out for six years and reported previously. The project is a collaboration between the Department of Medical Physics at the Toronto Odette Cancer Centre in Canada and the Department of Biomedical Imaging at the University of Malaya in Malaysia. Since 2001, medical physics graduate students at the University of Malaya have been taught by lecturers from Toronto every year, using the Internet as the main tool of communication.The pilot study explored the different methods that can be used to provide real-time interactive remote education, and delivered traditional classroom lectures as well as hands-on workshops.Another similar project was started in 2007 to offer real-time teaching to a class of medical physics students at Wuhan University in Hubei, China. There are new challenges as well as new opportunities associated with this project. By building an inventory of tools and experiences, the intent is to broaden the real-time teleteaching method to serve a wide community so that future students entering the field can have efficient access to high-quality education that will benefit the profession in the long term.

Matched MeSH terms: Physics

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