MyMedR

Displaying publications 161 - 180 of 276 in total

Abstract:

Sort:

The potential role of artificial intelligence-assisted chest X-ray imaging in detecting early-stage lung cancer in the community-a proposed algorithm for lung cancer screening in Malaysia

Sachithanandan A, Lockman H, Azman RR, Tho LM, Ban EZ, Ramon V

Med J Malaysia, 2024 Jan;79(1):9-14.
PMID: 38287751

INTRODUCTION: The poor prognosis of lung cancer has been largely attributed to the fact that most patients present with advanced stage disease. Although low dose computed tomography (LDCT) is presently considered the optimal imaging modality for lung cancer screening, its use has been hampered by cost and accessibility. One possible approach to facilitate lung cancer screening is to implement a risk-stratification step with chest radiography, given its ease of access and affordability. Furthermore, implementation of artificial-intelligence (AI) in chest radiography is expected to improve the detection of indeterminate pulmonary nodules, which may represent early lung cancer.
MATERIALS AND METHODS: This consensus statement was formulated by a panel of five experts of primary care and specialist doctors. A lung cancer screening algorithm was proposed for implementation locally.
RESULTS: In an earlier pilot project collaboration, AI-assisted chest radiography had been incorporated into lung cancer screening in the community. Preliminary experience in the pilot project suggests that the system is easy to use, affordable and scalable. Drawing from experience with the pilot project, a standardised lung cancer screening algorithm using AI in Malaysia was proposed. Requirements for such a screening programme, expected outcomes and limitations of AI-assisted chest radiography were also discussed.
CONCLUSION: The combined strategy of AI-assisted chest radiography and complementary LDCT imaging has great potential in detecting early-stage lung cancer in a timely manner, and irrespective of risk status. The proposed screening algorithm provides a guide for clinicians in Malaysia to participate in screening efforts.

Matched MeSH terms: X-Rays
Fulltext Effect of Diabetes Mellitus on Tuberculosis Treatment Outcomes among Tuberculosis Patients in Kelantan, Malaysia

Ahmad SR, Yaacob NA, Jaeb MZ, Hussin Z, Wan Mohammad WMZ

Iran J Public Health, 2020 Aug;49(8):1485-1493.
PMID: 33083325 DOI: 10.18502/ijph.v49i8.3892

Background: There is growing evidence that DM may play an important role in the occurrence of unsuccessful TB treatment outcomes. This study was undertaken to examine the prevalence of DM among TB population, compare the profile of TB patients with and without DM and determine the effect of DM on unsuccessful treatment outcomes among TB patients in Kelantan state, Malaysia from 2012 to 2016.
Methods: A cross sectional study was conducted in Sep 2017 using data from registered TB cases in Kelantan state, Malaysia from 2012 to 2016. The profile of TB patients with and without DM were compared in univariable analysis. Multiple logistic regression was used to determine association between DM and unsuccessful treatment outcomes.
Results: A total of 1854 TB patients were diagnosed with DM. The annual proportion was ranging from 26 to 29%. TB patients with DM had an older age, live single, low educational status, poor chest x ray finding and diagnosed with smear positive sputum compared to TB patients without DM. TB patients with DM had three times higher risk to develop unsuccessful TB treatment outcomes compared to TB patients without DM (95% CI 2.47-3.58; P = 0.012) in multivariable analysis.
Conclusion: Those with DM had the worst prognosis of TB outcomes among the significant risk factors. TB control program in Malaysia will need to expand efforts to focus on treatment of TB-DM patients to improve their cure rates in order to achieve the goals of tuberculosis elimination.

Matched MeSH terms: X-Rays
Fulltext Neutron-activated biodegradable samarium-153 acetylacetonate-poly-L-lactic acid microspheres for intraarterial radioembolization of hepatic tumors

Wong YH, Tan HY, Kasbollah A, Abdullah BJJ, Acharya RU, Yeong CH

World J Exp Med, 2020 Mar 30;10(2):10-25.
PMID: 32266125 DOI: 10.5493/wjem.v10.i2.10

BACKGROUND: Liver cancer is the 6th most common cancer in the world and the 4th most common death from cancer worldwide. Hepatic radioembolization is a minimally invasive treatment involving intraarterial administration of radioembolic microspheres.
AIM: To develop a neutron-activated, biodegradable and theranostics samarium-153 acetylacetonate (153SmAcAc)-poly-L-lactic acid (PLLA) microsphere for intraarterial radioembolization of hepatic tumors.
METHODS: Microspheres with different concentrations of 152SmAcAc (i.e., 100%, 150%, 175% and 200% w/w) were prepared by solvent evaporation method. The microspheres were then activated using a nuclear reactor in a neutron flux of 2 × 1012 n/cm2/s1, converting 152Sm to Samarium-153 (153Sm) via152Sm (n, γ) 153Sm reaction. The SmAcAc-PLLA microspheres before and after neutron activation were characterized using scanning electron microscope, energy dispersive X-ray spectroscopy, particle size analysis, Fourier transform infrared spectroscopy, thermo-gravimetric analysis and gamma spectroscopy. The in-vitro radiolabeling efficiency was also tested in both 0.9% sodium chloride solution and human blood plasma over a duration of 550 h.
RESULTS: The SmAcAc-PLLA microspheres with different SmAcAc contents remained spherical before and after neutron activation. The mean diameter of the microspheres was about 35 µm. Specific activity achieved for 153SmAcAc-PLLA microspheres with 100%, 150%, 175% and 200% (w/w) SmAcAc after 3 h neutron activation were 1.7 ± 0.05, 2.5 ± 0.05, 2.7 ± 0.07, and 2.8 ± 0.09 GBq/g, respectively. The activity of per microspheres were determined as 48.36 ± 1.33, 74.10 ± 1.65, 97.87 ± 2.48, and 109.83 ± 3.71 Bq for 153SmAcAc-PLLA microspheres with 100%, 150%, 175% and 200% (w/w) SmAcAc. The energy dispersive X-ray and gamma spectrometry showed that no elemental and radioactive impurities present in the microspheres after neutron activation. Retention efficiency of 153Sm in the SmAcAc-PLLA microspheres was excellent (approximately 99%) in both 0.9% sodium chloride solution and human blood plasma over a duration of 550 h.
CONCLUSION: The 153SmAcAc-PLLA microsphere is potentially useful for hepatic radioembolization due to their biodegradability, favorable physicochemical characteristics and excellent radiolabeling efficiency. The synthesis of the formulation does not involve ionizing radiation and hence reducing the complication and cost of production.

Matched MeSH terms: X-Rays
Fulltext Role of scintimammography in the diagnosis of breast cancer

Das BK, Biswal BM, Bhavaraju M

Malays J Med Sci, 2006 Jan;13(1):52-7.
PMID: 22589591 MyJurnal

X-ray mammography has been the backbone of early detection of breast cancer. Several large scale systematic studies have shown that judicious use of X-ray mammography can indeed save life. However, though reasonably sensitive, X-ray mammography lacks in specificity leading to many unnecessary biopsies. Scintimammography is a relatively new imaging method to demonstrate cancer tissue in the breast. A radiopharmaceutical agent (Tc-99m Sestamibi) is administered intravenously and images of the breast are taken under a Gamma Camera. There is no need for any manipulation like compression of the breast as required to be done during mammography. The radiopharmaceutical accumulates in the breast in the presence of cancer tissue which can easily be seen in the images. The affinity of the cancer tissue to this radiopharmaceutical is up to 9 times in comparison to normal breast tissue. Several multi centric studies with blinded image interpretation have established the sensitivity and specificity of scintimammography to be above 85 and 90 % respectively as compared to 89 and 14 % respectively for X-ray mammography. The positive and negative predictive values of scintimamography are 70 and 83 % as against 49 and 57 % respectively for X-ray mammography. With the increasing availability of Nuclear Medicine facilities it is expected that more and more patients will benefi with the use of this new imaging modality .

Matched MeSH terms: X-Rays
Thermoluminescence response of X-ray irradiated commercial chalk

Almugren KS, Sani SFA, Wandira R, Wahib N, Rozaila ZS, Khandaker MU, et al.

Appl Radiat Isot, 2019 Sep;151:102-110.
PMID: 31163392 DOI: 10.1016/j.apradiso.2019.04.027

Present research concerns the TL signal stored in chalk of the variety commercially available for writing on blackboards. Samples of this have been subjected to x-ray irradiation, the key dosimetric parameters investigated including dose and energy response, sensitivity, fading and glow curve analysis. Three types of chalk have been investigated, each in five different colours. The samples were annealed at 323 K prior to irradiation. For all three chalk types and all five colours, the dose response has been found linear over the investigated dose range, 0-9 Gy. Regardless of type or colour, photoelectric energy dependency is apparent at the low energy end down to the lowest investigated accelerating potential of 30 kV. Crayola (Yellow) has shown the greatest TL sensitivity, thus selection has been made to limit further analysis to this medium alone, specifically in respect of glow curve and fading study. In addition, elemental compositional and structural change characterizations were made for the same medium, utilizing Energy Dispersive X-Ray (EDX) and Raman spectroscopy, respectively.

Matched MeSH terms: X-Rays*
Preparation and quantification of radioactive particles for tracking hydrodynamic behavior in multiphase reactors

Yunos MA, Hussain SA, Yusoff HM, Abdullah J

Appl Radiat Isot, 2014 Sep;91:57-61.
PMID: 24907683 DOI: 10.1016/j.apradiso.2014.05.015

Radioactive particle tracking (RPT) has emerged as a promising and versatile technique that can provide rich information about a variety of multiphase flow systems. However, RPT is not an off-the-shelf technique, and thus, users must customize RPT for their applications. This paper presents a simple procedure for preparing radioactive tracer particles created via irradiation with neutrons from the TRIGA Mark II research reactor. The present study focuses on the performance evaluation of encapsulated gold and scandium particles for applications as individual radioactive tracer particles using qualitative and quantitative neutron activation analysis (NAA) and an X-ray microcomputed tomography (X-ray Micro-CT) scanner installed at the Malaysian Nuclear Agency.

Matched MeSH terms: X-Rays
Fulltext Overuse, overdose, overdiagnosis… overreaction?

Ho E

Biomed Imaging Interv J, 2010 Jul-Sep;6(3):e8.
PMID: 21611049 DOI: 10.2349/biij.6.3.e8

When x-rays were first discovered, the harmful effects of radiation had to be manifest in the early users before they were known. Today, radiation protection and safety have been established and the effects of radiation, as well as its risks, are known. Even so, medical radiation, in particular the growth in the use of computed tomography (CT), has resulted in soaring radiation doses received by the population in general. Inappropriate use has resulted in overuse, overdose and, perhaps, overdiagnosis, especially when used in screening. In the quest to control and curb the use of procedures involving radiation, however, we must be careful not to provoke a pandemic of irrational fear of radiation. Overreaction to the overuse and overdose of radiation might deter patients from life-saving procedures.

Matched MeSH terms: X-Rays
Fulltext Optical absorption and photoluminescence studies of gold nanoparticles deposited on porous silicon

Amran TS, Hashim MR, Al-Obaidi NK, Yazid H, Adnan R

Nanoscale Res Lett, 2013 Jan 18;8(1):35.
PMID: 23331761 DOI: 10.1186/1556-276X-8-35

We present an investigation on a coupled system consists of gold nanoparticles and silicon nanocrystals. Gold nanoparticles (AuNPs) embedded into porous silicon (PSi) were prepared using the electrochemical deposition method. Scanning electron microscope images and energy-dispersive X-ray results indicated that the growth of AuNPs on PSi varies with current density. X-ray diffraction analysis showed the presence of cubic gold phases with crystallite sizes around 40 to 58 nm. Size dependence on the plasmon absorption was studied from nanoparticles with various sizes. Comparison with the reference sample, PSi without AuNP deposition, showed a significant blueshift with decreasing AuNP size which was explained in terms of optical coupling between PSi and AuNPs within the pores featuring localized plasmon resonances.

Matched MeSH terms: X-Rays
Fulltext Electrochemical and Dry Sand Impact Erosion Studies on Carbon Steel

Naz MY, Ismail NI, Sulaiman SA, Shukrullah S

Sci Rep, 2015;5:16583.
PMID: 26561231 DOI: 10.1038/srep16583

This study investigated the dry and aqueous erosion of mild steel using electrochemical and dry sand impact techniques. In dry sand impact experiments, mild steel was eroded with 45 μm and 150 μm sand particles. Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and micro-hardness techniques were used to elaborate the surface morphology of the eroded samples. The results revealed significant change in morphology of the eroded samples. In-depth analysis showed that although the metal erosion due to larger particles was significantly higher, the fines also notably damaged the metal surface. The surface damages were appreciably reduced with decrease in impact angle of the accelerated particles. The maximum damages were observed at an impact angle of 90°. The hardness of the samples treated with 45 μm and 150 μm sand remained in the range of 88.34 to 102.31 VHN and 87.7 to 97.55 VHN, respectively. In electrochemical experiments, a triple electrode probe was added into the metal treatment process. The linear polarization resistance (LPR) measurements were performed in slurries having 5% (by weight) of sand particles. LPR of the samples treated with 45 μm and 150 μm sand slurries was calculated about 949 Ω.cm(2) and 809 Ω.cm(2), respectively.

Matched MeSH terms: X-Rays
Molecular Structures of Isomeric Ortho, Meta, and Para Bromo-Substituted α-Methylsulfonyl-α-diethoxyphosphoryl Acetophenones by X-ray and DFT Molecular Orbital Calculations

Rodrigues A, Olivato PR, Zukerman-Schpector J, Maganhi SH, Reis AK, Tiekink ER

J Phys Chem A, 2015 Aug 13;119(32):8714-23.
PMID: 26213179 DOI: 10.1021/acs.jpca.5b04019

The X-ray single crystal analysis of isomeric ortho, meta, and para bromo-substituted α-methylsulfonyl-α-diethoxyphosphoryl acetophenones showed that this class of compound adopts synclinal (gauche) conformations for both [-P(O)(OEt)2] and [-S(O)2Me] groups, with respect to the carbonyl functional group. The phosphonate, sulfonyl, and carbonyl functional groups are joined through an intramolecular network of attractive interactions, as detected by molecular orbital calculations at the M06-2X/6-31G(d,p) level. These interactions are responsible for the more stable conformations in the gas phase, which also persist in the solid-state structures. The main structural distinction in the title compounds relates to the torsion angle of the aryl group (with respect to the carbonyl group), which gives rise to different interactions in the crystal packing, due to the different positions of the Br atom.

Matched MeSH terms: X-Rays
Functionalized fluorescent terephthalate monomers and their attempted polyester formation

Choo YSL, Giamberini M, Antonio J, Waddell PG, Benniston AC

Org Biomol Chem, 2020 Nov 04;18(42):8735-8745.
PMID: 33094783 DOI: 10.1039/d0ob01533d

The reaction of diethyl 2,5-bis(tert-butyl)phenoxy-3,6-dihydroxyterephthalate (1) with tetraethylene glycol di(p-toluenesulfonate) under high-dilution conditions afforded several isolated products. Two products were identified as macrocycles with one being the 1 + 1 crown ether derivative 3 (10% yield), and the second being the 2 + 2 crown ether compound D3 (19% yield). The X-ray structure for 3 was determined with the asymmetric unit observed to comprise half of the molecule. The small crown ether ring of 3 interacts with K+ or H+ ions in MeOH, but binding is weak and the macrocyclic cavity is too small to fully encapsulate the K+ ion. Transesterification of compounds 1, its methylated version 2 and 3 with diols such as ethylene glycol or 1,4-butandiol produced monomers (M1-M3) which were reacted with terephthaloyl chloride. Short oligomers were produced (PolyM1-PolyM3) rather than extensive polymeric materials and all displayed solid state fluorescence. The absorption and fluorescence properties of M1-M2 and their polymers can be related to subtle structural changes. The Stokes shift for M2 of 15 627 cm-1 in DCM is one of the largest observed for a simple organic chromophore in fluid solution.

Matched MeSH terms: X-Rays
Fulltext Validation of the dose distributions with Monte Carlo simulation for carbon ion cancer therapy

Ying, C.K., W.A. Kamil, Matsufuji, Naruhiro

Journal of Biomedical and Clinical Sciences, 2017;2(2):1-7.
MyJurnal

Charged particle therapy with carbon ions has advantages over conventional radiotherapy using x-ray beams. The application of charged particle therapy has rapidly increased over the last decades. This is due to its characteristic Bragg peak which has relatively low entrance doses and favourable doses distribution. In this research work, Geant4 based Monte Carlo simulation (MC) method has been used to calculate the radiation transportation and dose distributions in tissue-like media. The main objective of the work was to compare the Geant4 simulated depth dose distributions with experimental measurements and verify the capability of the geant4 simulation toolkit. The carbon ion beams for the therapeutic energy of 350 MeV/u and 400 MeV/u respectively were simulated, with the same settings as the experimental work carried out at the treatment room at Heavy Ion Medical Accelerator (HIMAC), National Institute of Radiological Sciences (NIRS), Chiba, Japan. The simulation results were verified with measurements data. The work was to measure the accuracy and quality of the dose distributions by Geant4 MC methods. The results show that the Bragg peak and spread out Bragg peak (SOBP) distributions in simulation has fairly good agreement with measurements.

Matched MeSH terms: X-Rays
Fulltext Pleuritic chest pain and fever: An unusual presentation of aortic dissection

Mohamed-Yassin MS, Baharudin N, Ramli AS, Hashim H

Malays Fam Physician, 2019;14(1):47-52.
PMID: 31289633

It remains a challenge to diagnose aortic dissection in primary care, as classic clinical features are not always present. This case describes an atypical presentation of aortic dissection, in which the patient walked in with pleuritic central chest pain associated with a fever and elevated C-reactive protein. Classic features of tearing pain, pulse differentials, and a widened mediastinum on chest X-ray were absent. This unusual presentation highlights the need for a heightened level of clinical suspicion for aortic dissection in the absence of classic features. The case is discussed with reference to the literature on the sensitivity and specificity of the classic signs and symptoms of aortic dissection. A combination of the aortic dissection detection risk score (ADD-RS) and D-dimer test is helpful in ruling out this frequently lethal condition.

Matched MeSH terms: X-Rays
Fulltext Self-Fluxing Mechanism in Geopolymerization for Low-Sintering Temperature of Ceramic

Jamil NH, Abdullah MMAB, Pa FC, Mohamad H, Ibrahim WMAW, Amonpattaratkit P, et al.

Materials (Basel), 2021 Mar 10;14(6).
PMID: 33801862 DOI: 10.3390/ma14061325

Kaolin, theoretically known as having low reactivity during geopolymerization, was used as a source of aluminosilicate materials in this study. Due to this concern, it is challenging to directly produce kaolin geopolymers without pre-treatment. The addition of ground granulated blast furnace slag (GGBS) accelerated the geopolymerization process. Kaolin-GGBS geopolymer ceramic was prepared at a low sintering temperature due to the reaction of the chemical composition during the initial stage of geopolymerization. The objective of this work was to study the influence of the chemical composition towards sintering temperature of sintered kaolin-GGBS geopolymer. Kaolin-GGBS geopolymer was prepared with a ratio of solid to liquid 2:1 and cured at 60 °C for 14 days. The cured geopolymer was sintered at different temperatures: 800, 900, 1000, and 1100 °C. Sintering at 900 °C resulted in the highest compressive strength due to the formation of densified microstructure, while higher sintering temperature led to the formation of interconnected pores. The difference in the X-ray absorption near edge structure (XANES) spectra was related to the phases obtained from the X-ray diffraction analysis, such as akermanite and anothite. Thermal analysis indicated the stability of sintered kaolin-GGBS geopolymer when exposed to 1100 °C, proving that kaolin can be directly used without heat treatment in geopolymers. The geopolymerization process facilitates the stability of cured samples when directly sintered, as well as plays a significant role as a self-fluxing agent to reduce the sintering temperature when producing sintered kaolin-GGBS geopolymers.

Matched MeSH terms: X-Rays
Fulltext Fabrication and Characterization of High-Quality UV Photodetectors Based ZnO Nanorods Using Traditional and Modified Chemical Bath Deposition Methods

Abdulrahman AF, Ahmed SM, Barzinjy AA, Hamad SM, Ahmed NM, Almessiere MA

Nanomaterials (Basel), 2021 Mar 09;11(3).
PMID: 33803274 DOI: 10.3390/nano11030677

Ultraviolet (UV) photodetectors (PDs) based on high-quality well-aligned ZnO nanorods (NRs) were fabricated using both modified and conventional chemical bath deposition (CBD) methods. The modified chemical bath deposition (M-CBD) method was made by adding air bubbles to the growth solution during the CBD process. The viability and effectiveness of M-CBD were examined by developing UV PDs based on ZnO NRs. The ZnO nano-seed layer was coated on a glass substrate utilizing radiofrequency (RF) sputtering. The impact of the different growth-times on morphology, growth rate, crystal structure, and optical and chemical properties were investigated systematically using different characterization techniques, such as field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD) analysis, UV-VIS double beam spectrometer, and energy dispersive X-ray analysis (EDX), respectively. The Al/ZnO UV PDs based on ZnO nanorods were fabricated with optimum growth conditions through the two methods of preparation. This study showed that the synthesized ZnO NRs using the M-CBD method for different growth times possess better properties than the conventional method under similar deposition conditions. Despite having the highest aspect ratio and growth rate of ZnO NRs, which were found at 4 h growth duration for both methods, the aspect ratio of ZnO NRs using the M-CBD technique was comparatively higher than the conventional CBD method. Besides, the UV PDs fabricated by the M-CBD method at 5 V bias voltage showed high sensitivity, short response time, quick recovery time, high gain, low dark current, and high photocurrent compared with the UV PD device fabricated by the conventional CBD method.

Matched MeSH terms: X-Rays
Aggressive diuretic therapy for a large solitary lung lesion

Mohd Firdaus MAB, Zulkafli H, Said MR, Hadi MF, Sukhari S, Arjan Singh RS

Med J Malaysia, 2020 11;75(6):750-751.
PMID: 33219192

Pseudotumour of the lung is a rare chest x-ray finding among patients who present with fluid overload. It is caused by loculated pleural effusion in the lung fissures. Unfortunately, the occurrence of pseudotumour can be misleading and sometimes can lead to unnecessary investigation and emotional stress to the patient. We present here a case of a 61-year-old gentleman with a known history of hypertension, diabetes mellitus and dyslipidemia who presented at University Malaya Medical Centre with symptoms of fluid overload and a right middle lobe mass on chest x-ray. The right middle lobe mass disappeared entirely after being treated with aggressive diuretic therapy. A diagnosis of pseudotumour was made and described in this case report.

Matched MeSH terms: X-Rays
Fulltext Influence of Solvents' Polarity on the Physicochemical Properties and Photocatalytic Activity of Titania Synthesized Using Deinbollia pinnata Leaves

Rufai Y, Chandren S, Basar N

Front Chem, 2020;8:597980.
PMID: 33344417 DOI: 10.3389/fchem.2020.597980

Nanotechnology is one of the most interesting areas of research due to its flexibility to improve or form new products from nanoparticles (NPs), and as a fast, greener, more eco-friendly and sustainable solution to technological and environmental challenges. Among metal oxides of photocatalytic performance, the use of titania (TiO2) as photocatalyst is most popular due to its unique optical and electronic properties. Despite the wide utilization, the synthesis of TiO2 NPs bears many disadvantages: it utilizes various less environmental-friendly chemicals, high cost, requires high pressure and energy, and potentially hazardous physical and chemical methods. Hence, the development of green synthesis approach with eco-friendly natural products can be used to overcome these adverse effects. In this work, TiO2 NPs have been prepared by using Deinbollia pinnata leaves extracts, obtained by different solvents (n-hexane, ethyl acetate, and ethanol) with different polarities. The extracts acted as the reducing agent, while titanium isopropoxide as the precursor and water as the solvent. X-ray diffraction (XRD) pattern confirmed the synthesized TiO2 consist of anatase phase in high purity, with average crystallite size in the range of 19-21 nm. Characterization by using field emission scanning electron microscopy (FESEM) showed the TiO2 NPs possess a uniform semi-spherical shape in the size range of 33-48 nm. The energy dispersive X-ray (EDX) spectra of green TiO2 NPs showed two peaks for the main elements of Ti (61 Wt.%) and O (35 Wt.%). The band-gap energy of 3.2 eV was determined using UV-Vis spectroscopy. From the nitrogen sorption analysis, type V isotherm of the material was obtained, with BET surface area of 31.77 m2/g. The photocatalytic activity of synthesized TiO2 was evaluated for photodegradation of methyl orange (MO) under UV light irradiation. Based on the results, it is shown that TiO2 NPs synthesized with D. pinnata leaves extracted using ethyl acetate showed the most effective photodegradation performance, achieving 98.7% of MO conversion within 150 min. It can be concluded that the use of plant extracts in synthesis with TiO2 managed to produce highly crystalline anatase TiO2 with superior photocatalytic activity in the photodegradation of organic dye.

Matched MeSH terms: X-Rays
Fulltext Anomalous metal segregation in lithium-rich material provides design rules for stable cathode in lithium-ion battery

Lin R, Hu E, Liu M, Wang Y, Cheng H, Wu J, et al.

Nat Commun, 2019 04 09;10(1):1650.
PMID: 30967531 DOI: 10.1038/s41467-019-09248-0

Despite the importance of studying the instability of delithiated cathode materials, it remains difficult to underpin the degradation mechanism of lithium-rich cathode materials due to the complication of combined chemical and structural evolutions. Herein, we use state-of-the-art electron microscopy tools, in conjunction with synchrotron X-ray techniques and first-principle calculations to study a 4d-element-containing compound, Li2Ru0.5Mn0.5O3. We find surprisingly, after cycling, ruthenium segregates out as metallic nanoclusters on the reconstructed surface. Our calculations show that the unexpected ruthenium metal segregation is due to its thermodynamic insolubility in the oxygen deprived surface. This insolubility can disrupt the reconstructed surface, which explains the formation of a porous structure in this material. This work reveals the importance of studying the thermodynamic stability of the reconstructed film on the cathode materials and offers a theoretical guidance for choosing manganese substituting elements in lithium-rich as well as stoichiometric layer-layer compounds for stabilizing the cathode surface.

Matched MeSH terms: X-Rays
Fulltext Novel Functionalized Polythiophene-Coated Fe₃O₄ Nanoparticles for Magnetic Solid-Phase Extraction of Phthalates

Baharin SNA, Muhamad Sarih N, Mohamad S

Polymers (Basel), 2016 Apr 28;8(5).
PMID: 30979266 DOI: 10.3390/polym8050117

Poly(phenyl-(4-(6-thiophen-3-yl-hexyloxy)-benzylidene)-amine) (P3TArH) was successfully synthesized and coated on the surface of Fe₃O₄ magnetic nanoparticles (MNPs). The nanocomposites were characterized by Fourier transform infra-red (FTIR), X-ray diffractometry (XRD), Brunauer-Emmett-Teller (BET) surface area analysis, analyzer transmission electron microscopy (TEM) and vibrating sample magnetometry (VSM). P3TArH-coated MNPs (MNP@P3TArH) showed higher capabilities for the extraction of commonly-used phthalates and were optimized for the magnetic-solid phase extraction (MSPE) of environmental samples. Separation and determination of the extracted phthalates, namely dimethyl phthalate (DMP), diethyl phthalate (DEP), dipropyl phthalate (DPP), dibutyl phthalate (DBP), butyl benzyl phthalate (BBP), dicyclohexyl phthalate (DCP), di-ethylhexyl phthalate (DEHP) and di-n-octyl phthalate (DNOP), were conducted by a gas chromatography-flame ionization detector (GC-FID). The best working conditions were as follows; sample at pH 7, 30 min extraction time, ethyl acetate as the elution solvent, 500-µL elution solvent volumes, 10 min desorption time, 10-mg adsorbent dosage, 20-mL sample loading volume and 15 g·L-1 concentration of NaCl. Under the optimized conditions, the analytical performances were determined with a linear range of 0.1⁻50 µg·L-1 and a limit of detection at 0.08⁻0.468 µg·L-1 for all of the analytes studied. The intra-day (n = 7) and inter-day (n = 3) relative standard deviations (RSD%) of three replicates were each demonstrated in the range of 3.7⁻4.9 and 3.0⁻5.0, respectively. The steadiness and reusability studies suggested that the MNP@P3TArH could be used up to five cycles. The proposed method was executed for the analysis of real water samples, namely commercial bottled mineral water and bottled fresh milk, whereby recoveries in the range of 68%⁻101% and RSD% lower than 7.7 were attained.

Matched MeSH terms: X-Rays
Fulltext Dosimetric study of Rhizophora Spp. particle board using Gafchromic XRQA2 film

A. N. Azahari, N. D.M Yusob, H.A. Saidun, N.K.Y Ali, R. Abdullah, R. Hashim, et al.

Malaysian Journal of Medicine and Health Sciences, 2020;16(102):46-50.
MyJurnal

Introduction: Various phantom with varied materials has been proposed to replace the human body. Besides, there is always a demand to use the local material as a phantom material, which is readily available and inexpensive. Wood is usually preferred because it is multifunction, environmentally friendly, low in toxic, inexpensive, as well as easy to use and prepare. Previous studies have found that Rhizophora spp. is a suitable natural source material and has been suggested due to its comparable dosimetric properties to commercial phantom. Methods: In this study, fabricated Rhizophora spp. particleboards phantom was opted as a solid-equivalent phantom medium at low energy photon beams using Gafchromic film x-ray quality assurance 2 (XRQA2). Additionally, the characteristics of XRQA2 film in the diagnostic energy range were generated. Results: Interestingly, the density of the fabricated Rhizophora spp particleboards was observed to have the same density with the water equivalent material (ρ= 1.00 g.cm-3) and has shown to have loosened agreement with PDD of water phantom at approximately 25% of the dose error. Also, further analysis using XRQA 2 film showed that energy was independent at different ranges. Conclusion: The analysis of fabricated Rhizophora spp particleboards undertaken here has extended our knowledge of the possibility of man- ufacturing cost-effective water equivalent phantom by using binder-less particleboard from Rhizophora spp. There- fore, a definite need for smaller interspacing particles should be considered to elevate the potential of Rhizophora spp particle boards as water equivalent materials.

Matched MeSH terms: X-Rays

Filters

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links