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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
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*
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
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
Surveying trends in radiation oncology medical physics in the Asia Pacific Region

Kron T, Healy B, Ng KH

Phys Med, 2016 Jul;32(7):883-8.
PMID: 27320695 DOI: 10.1016/j.ejmp.2016.06.001

OBJECTIVE: Our study aims to assess and track work load, working conditions and professional recognition of radiation oncology medical physicists (ROMPs) in the Asia Pacific Region over time.
METHODS: A structured questionnaire was mailed in 2008, 2011 and 2014 to senior medical physicists representing 23 countries. The questionnaire covers 7 themes: education and training including certification; staffing; typical tasks; professional organisations; resources; research and teaching; job satisfaction.
RESULTS: Across all surveys the response rate was >85% with the replies representing practice affecting more than half of the world's population. The expectation of ROMP qualifications (MSc and between 1 and 3years of clinical experience) has not changed much over the years. However, compared to 2008, the number of medical physicists in many countries has doubled. Formal professional certification is only available in a small number of countries. The number of experienced ROMPs is small in particular in low and middle income countries. The increase in staff numbers from 2008 to 2014 is matched by a similar increase in the number of treatment units which is accompanied by an increase in treatment complexity. Many ROMPs are required to work overtime and not many find time for research. Resource availability has only improved marginally and ROMPs still feel generally overworked, but professional recognition, while varying widely, appears to be improving slowly.
CONCLUSION: While number of physicists and complexity of treatment techniques and technologies have increased significantly, ROMP practice remains essentially unchanged over the last 6years in the Asia Pacific Region.

Matched MeSH terms: Health Physics/trends*
Leadership and mentoring in medical physics: The experience of a medical physics international mentoring program

Santos JC, Goulart LF, Giansante L, Lin YH, Sirico ACA, Ng AH, et al.

Phys Med, 2020 Aug;76:337-344.
PMID: 32759035 DOI: 10.1016/j.ejmp.2020.07.023

Mentoring aims to improve careers and create benefits for the participants' personal and professional lives. Mentoring can be an individual or a shared experience for a group, while the mentor's role remains the same in both models. Mentors should increase confidence, teach, inspire, and set examples, helping the mentees to mould their path, contributing to the pursuit of their personal and professional goals. This study aims to report on the experience of early-career medical physics professionals and postgraduate students participating in a global mentoring program and to assess the impact of this activity on their professional development. The objectives of this mentoring program are to develop leadership roles among young medical physicists and to provide guidance and support. An online questionnaire was administered to the mentee participants. The analysis of their responses is reported in this work and the current status of the programme was examined using a SWOT analysis. In general, the mentoring experience had a positive impact on the mentees. The mentors were found especially helpful in the decision-making situations and in other conflicts that may arise with career development. Additionally, the mentees felt that mentoring contributed to the development of leadership skills required for the job market and assist in personal development. This paper concludes that participation of young medical physicists in a mentoring group program is beneficial to their career and therefore should be encouraged.

Matched MeSH terms: Physics
Medical physicists in Malaysia: A national workforce survey 2019

Wong JHD, Zin HM, Pawanchek M, Ng KH

Phys Med, 2019 Nov;67:40-49.
PMID: 31669669 DOI: 10.1016/j.ejmp.2019.10.019

OBJECTIVE: Medical physics in Malaysia is still considered a young profession. This workforce survey aims to understand the status, aspirations, motivation and experiences of medical physicists (MPs) in the country. A subsection of this survey also aims to understand the role of women.
METHOD: A survey was carried out between April 20 and May 30, 2018 by a working group under the Medical Physics Division of the Malaysian Institute of Physics (IFM). The survey form was designed using Google Form and sent to various public and private institutions nationwide that employed MPs registered with IFM.
RESULTS: A total of 106 responses (28% men and 72% women) were analysed. This represented 30% of the medical physics workforce. Majority of them had postgraduate degrees, but their clinical training is mostly obtained on the job with no certification. The number of low-ranking female MPs was disproportionately high. MPs worked long hours and achieving work-life balance (WLB) was a challenge. Factors that improved their WLB included working close to home, having a supportive manager and flexible working hours. Most MPs aspired to become professional and mentor younger compatriots, besides contributing to patient care and research. Gender discrimination was reportedly low.
CONCLUSION: Medical physics in Malaysia is growing and has a strong representation of women. In future, they would probably take over the top management from their male counterparts, whose number had stagnated. A united effort was essential to set up a proper clinical training system to train clinically qualified MPs.

Matched MeSH terms: Physics/statistics & numerical data*
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*
Shear wave elastography in chronic kidney disease - the physics and clinical application

Ng KH, Wong JHD, Leong SS

Phys Eng Sci Med, 2024 Mar;47(1):17-29.
PMID: 38078996 DOI: 10.1007/s13246-023-01358-w

Chronic kidney disease is a leading public health problem worldwide. The global prevalence of chronic kidney disease is nearly five hundred million people, with almost one million deaths worldwide. Estimated glomerular filtration rate, imaging such as conventional ultrasound, and histopathological findings are necessary as each technique provides specific information which, when taken together, may help to detect and arrest the development of chronic kidney disease, besides managing its adverse outcomes. However, estimated glomerular filtration rate measurements are hampered by substantial error margins while conventional ultrasound involves subjective assessment. Although histopathological assessment is the best tool for evaluating the severity of the renal pathology, it may lead to renal insufficiency and haemorrhage if complications occurred. Ultrasound shear wave elastography, an emerging imaging that quantifies tissue stiffness non-invasively has gained interest recently. This method applies acoustic force pulses to generate shear wave within the tissue that propagate perpendicular to the main ultrasound beam. By measuring the speed of shear wave propagation, the tissue stiffness is estimated. This paper reviews the literature and presents our combined experience and knowledge in renal shear wave elastography research. It discusses and highlights the confounding factors on shear wave elastography, current and future possibilities in ultrasound renal imaging and is not limited to new sophisticated techniques.

Matched MeSH terms: Physics
Search for Physics Beyond the Standard Model in Events with High-Momentum Higgs Bosons and Missing Transverse Momentum in Proton-Proton Collisions at 13 TeV

Sirunyan AM, Tumasyan A, Adam W, Ambrogi F, Asilar E, Bergauer T, et al.

Phys Rev Lett, 2018 Jun 15;120(24):241801.
PMID: 29956995 DOI: 10.1103/PhysRevLett.120.241801

A search for physics beyond the standard model in events with one or more high-momentum Higgs bosons, H, decaying to pairs of b quarks in association with missing transverse momentum is presented. The data, corresponding to an integrated luminosity of 35.9 fb^{-1}, were collected with the CMS detector at the LHC in proton-proton collisions at the center-of-mass energy sqrt[s]=13 TeV. The analysis utilizes a new b quark tagging technique based on jet substructure to identify jets from H→bb[over ¯]. Events are categorized by the multiplicity of H-tagged jets, jet mass, and the missing transverse momentum. No significant deviation from standard model expectations is observed. In the context of supersymmetry (SUSY), limits on the cross sections of pair-produced gluinos are set, assuming that gluinos decay to quark pairs, H (or Z), and the lightest SUSY particle, LSP, through an intermediate next-to-lightest SUSY particle, NLSP. With large mass splitting between the NLSP and LSP, and 100% NLSP branching fraction to H, the lower limit on the gluino mass is found to be 2010 GeV.

Matched MeSH terms: Physics
Search for Physics beyond the Standard Model in Events with Overlapping Photons and Jets

Sirunyan AM, Tumasyan A, Adam W, Ambrogi F, Bergauer T, Brandstetter J, et al.

Phys Rev Lett, 2019 Dec 13;123(24):241801.
PMID: 31922872 DOI: 10.1103/PhysRevLett.123.241801

Results are reported from a search for new particles that decay into a photon and two gluons, in events with jets. Novel jet substructure techniques are developed that allow photons to be identified in an environment densely populated with hadrons. The analyzed proton-proton collision data were collected by the CMS experiment at the LHC, in 2016 at sqrt[s]=13 TeV, and correspond to an integrated luminosity of 35.9 fb^{-1}. The spectra of total transverse hadronic energy of candidate events are examined for deviations from the standard model predictions. No statistically significant excess is observed over the expected background. The first cross section limits on new physics processes resulting in such events are set. The results are interpreted as upper limits on the rate of gluino pair production, utilizing a simplified stealth supersymmetry model. The excluded gluino masses extend up to 1.7 TeV, for a neutralino mass of 200 GeV and exceed previous mass constraints set by analyses targeting events with isolated photons.

Matched MeSH terms: Physics
Fulltext Twenty Years of the Malaysian Association of Medical Physics: Looking Back to Move Forwards

Zin, H. M.

Physics and Technology in Medicine, 2020;1(2):1-6.
MyJurnal

The Malaysian Association of Medical Physics (MAMP) was set up in the year 2000 to promote and further develop the field that was relatively new in Malaysia. The article briefly summarises key developments in medical physics since the first discovery of x-rays in 1895. The resulted rapid progress in the field was also highlighted and related to the pace of development in Malaysia. Key activities organised by MAMP were also addressed. The international practices related to the field and the profession were highlighted and compared to the current status in Malaysia. Although the field has progressed well in the country, there are several gaps identified to further improve the field and the profession in Malaysia.

Matched MeSH terms: Physics
Fulltext Employing of Trukhan Model to Estimate Ion Transport Parameters in PVA Based Solid Polymer Electrolyte

Aziz SB, B Marif R, Brza MA, Hamsan MH, Kadir MFZ

Polymers (Basel), 2019 Oct 16;11(10).
PMID: 31623158 DOI: 10.3390/polym11101694

In the current paper, ion transport parameters in poly (vinyl alcohol) (PVA) based solid polymer electrolyte were examined using Trukhan model successfully. The desired amount of lithium trifluoromethanesulfonate (LiCF3SO3) was dissolved in PVA host polymer to synthesis of solid polymer electrolytes (SPEs). Ion transport parameters such as mobility (μ), diffusion coefficient (D), and charge carrier number density (n) are investigated in detail using impedance spectroscopy. The data results from impedance plots illustrated a decrement of bulk resistance with an increase in temperature. Using electrical equivalent circuits (EEC), electrical impedance plots (ZivsZr) are fitted at various temperatures. The results of impedance study demonstrated that the resistivity of the sample decreases with increasing temperature. The decrease of resistance or impedance with increasing temperature distinguished from Bode plots. The dielectric constant and dielectric loss values increased with an increase in temperature. The loss tangent peaks shifted to higher frequency region and the intensity increased with an increase in temperature. In this contribution, ion transport as a complicated subject in polymer physics is studied. The conductivity versus reciprocal of temperature was found to obey Arrhenius behavior type. The ion transport mechanism is discussed from the tanδ spectra. The ion transport parameters at ambient temperature are found to be 9 × 10-8 cm2/s, 0.8 × 1017 cm-3, and 3 × 10-6 cm2/Vs for D, n, andμ respectively. All these parameters have shown increasing as temperature increased. The electric modulus parameters are studied in an attempt to understand the relaxation dynamics and to clarify the relaxation process and ion dynamics relationship.

Matched MeSH terms: Physics
A review on modeling the channel potential in Multi-Gate MOSFETs

Hossein Mohammadi, Huda Abdullah, Chang FD

Sains Malaysiana, 2014;43:861-866.

This paper attempts to give a detailed review and provide a complete description on the technology, physics and modeling of various Multi-Gate MOSFETs. It consists of a synopsis of mathematical depiction of the potential distribution along the channel of various MG-MOSFETS which can be made to enable fast computer analysis of device behavior. This serves a link between process technology and circuit design. This review demonstrates that this technology is strongly desired in nanoscale domain and there is a plenty demand for analytical model which can explain the physics and operation of the devices perfectly.

Matched MeSH terms: Physics
The physics interviewing project: a tour of interviews in Asia

Callen E, Scadron M

Science, 1978 Jun 2;200(4345):1018-22.
PMID: 17740674

The Physics Interviewing Project assists graduate physics departments in evaluating foreign applicants. Supported by some 20 universities, two interviewers, both working scientists, travel abroad and interview students individually for about 1 hour each. Prospective teaching assistants are rated on physics knowledge, problem-solving ability, and English language proficiency. Ratings on all interviewees are sent to all supporting schools and other schools as requested. The Project aids able students from countries that have no physics Ph.D. programs (Indonesia, Malaysia, Thailand) to obtain assistantships and Ph.D.'s abroad, assists in the technological development of those countries, and helps U.S. schools in selecting the most promising foreign candidates. A similar program should be beneficial in other sciences.

Matched MeSH terms: Physics
Fulltext Direct synthesis of nanodiamonds by femtosecond laser irradiation of ethanol

Nee CH, Yap SL, Tou TY, Chang HC, Yap SS

Sci Rep, 2016 Sep 23;6:33966.
PMID: 27659184 DOI: 10.1038/srep33966

Carbon nanomaterials exhibit novel characteristics including enhanced thermal, electrical, mechanical, and biological properties. Nanodiamonds; first discovered in meteorites are found to be biocompatible, non-toxic and have distinct optical properties. Here we show that nanodiamonds with the size of <5 nm are formed directly from ethanol via 1025 nm femtosecond laser irradiation. The absorption of laser energy by ethanol increased non-linearly above 100 μJ accompanied by a white light continuum arises from fs laser filamentation. At laser energy higher than 300 μJ, emission spectra of C, O and H in the plasma were detected, indicating the dissociation of C2H5OH. Nucleation of the carbon species in the confined plasma within the laser filaments leads to the formation of nanodiamonds. The energy dependence and the roles of the nonlinear phenomenon to the formation of homogeneous nanodiamonds are discussed. This work brings new possibility for bottom-up nanomaterials synthesis based on nano and ultrafast laser physics.

Matched MeSH terms: Physics
Fulltext Comparing photoelectrochemical water oxidation, recombination kinetics and charge trapping in the three polymorphs of TiO2

Moss B, Lim KK, Beltram A, Moniz S, Tang J, Fornasiero P, et al.

Sci Rep, 2017 06 07;7(1):2938.
PMID: 28592816 DOI: 10.1038/s41598-017-03065-5

In this article we present the first comparative study of the transient decay dynamics of photo-generated charges for the three polymorphs of TiO2. To our knowledge, this is the first such study of the brookite phase of TiO2 over timescales relevant to the kinetics of water splitting. We find that the behavior of brookite, both in the dynamics of relaxation of photo-generated charges and in energetic distribution, is similar to the anatase phase of TiO2. Moreover, links between the rate of recombination of charge carriers, their energetic distribution and the mode of transport are made in light of our findings and used to account for the differences in water splitting efficiency observed across the three polymorphs.

Matched MeSH terms: Physics
Nuclear science and technology in the Malaysian context: Three phases of technoscientific knowledge transfer (ETTLG)

Lee CAL

Stud Hist Philos Sci, 2019 10;77:130-140.
PMID: 31701877 DOI: 10.1016/j.shpsa.2017.10.002

This essay considers the development of the nuclear science programme in Malaysia from a transnational perspective by examining the interactions between state agents and other external nuclear-knowledge/technology related actors and agents. Going beyond the model of knowledge diffusion that brings together concerns articulated in Harris's (2011) geographies of long distance knowledge and Reinhardt's (2011) role of the expert in knowledge transfer, the proposed three-phase model of knowledge transfer theorises the pathways undertaken by a late-blooming participant of modern science and technology as the latter moves from epistemic dependency to increasing independence despite the hurdles encountered, and the underdevelopment of many areas of its technoscientific economy. The model considers tensions stemming from the pressures of expediency for meeting national developmental goals on the one side, and the call to support the objectives of basic science on the other. The three phases of the model are epistemic transition, epistemic transplantation and localisation, and epistemic generation (ETTLG). As additional support for the proposed model, three arguments are proffered as deeper explanations of the epistemic goal by using Malaysia as a case study: knowledge transfer for political legitimization, knowledge transfer for countering agnotology, and knowledge transfer for social engineering and science diplomacy.

Matched MeSH terms: Nuclear Physics*

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