Displaying publications 121 - 140 of 215 in total

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  1. Fulltext Multivariate visualization of the global COVID-19 pandemic: A comparison of 161 countries
    Teh JKL, Bradley DA, Chook JB, Lai KH, Ang WT, Teo KL, et al.
    PLoS One, 2021;16(5):e0252273.
    PMID: 34048477 DOI: 10.1371/journal.pone.0252273
    BACKGROUND: The aim of the study was to visualize the global spread of the COVID-19 pandemic over the first 90 days, through the principal component analysis approach of dimensionality reduction.

    METHODS: This study used data from the Global COVID-19 Index provided by PEMANDU Associates. The sample, representing 161 countries, comprised the number of confirmed cases, deaths, stringency indices, population density and GNI per capita (USD). Correlation matrices were computed to reveal the association between the variables at three time points: day-30, day-60 and day-90. Three separate principal component analyses were computed for similar time points, and several standardized plots were produced.

    RESULTS: Confirmed cases and deaths due to COVID-19 showed positive but weak correlation with stringency and GNI per capita. Through principal component analysis, the first two principal components captured close to 70% of the variance of the data. The first component can be viewed as the severity of the COVID-19 surge in countries, whereas the second component largely corresponded to population density, followed by GNI per capita of countries. Multivariate visualization of the two dominating principal components provided a standardized comparison of the situation in the161 countries, performed on day-30, day-60 and day-90 since the first confirmed cases in countries worldwide.

    CONCLUSION: Visualization of the global spread of COVID-19 showed the unequal severity of the pandemic across continents and over time. Distinct patterns in clusters of countries, which separated many European countries from those in Africa, suggested a contrast in terms of stringency measures and wealth of a country. The African continent appeared to fare better in terms of the COVID-19 pandemic and the burden of mortality in the first 90 days. A noticeable worsening trend was observed in several countries in the same relative time frame of the disease's first 90 days, especially in the United States of America.

  2. Fulltext Levels and health risk assessment of heavy metals in dried fish consumed in Bangladesh
    Rakib MRJ, Jolly YN, Enyoh CE, Khandaker MU, Hossain MB, Akther S, et al.
    Sci Rep, 2021 07 19;11(1):14642.
    PMID: 34282166 DOI: 10.1038/s41598-021-93989-w
    As a cheap source of high-quality protein, healthy fats and essential nutrients, dried fish is a common item in the daily diet of the Bangladesh populace. In this study, ten types of widely consumed dried fish (H. neherius, T. lepturu, P.chinensis, P. affinis, A. mola, P. microdon, I. megaloptera, C. dussumieri, L. calcarifer, and G. chapra) were analyzed for Cr, Mn, Fe, Co, Cu, Zn, Se, Rb, Hg, Pb, Ni and As by using an Energy Dispersive X-ray Fluorescence (EDXRF) technique. The concentration of the studied metals was found in the order Fe > Zn > Hg > Cu > Se > Cr > Mn > Co > Rb > Pb, while As and Ni were below the limit of detection. All fish species showed moderate to high pollution, where the species H. Neherius and P. Chinensis are the most and least polluted ones, respectively. The probable source of contamination is the leaching from the drying pans into the fish samples, atmospheric deposition, anthropogenic contamination, etc. of the water body where these fish were harvested. The calculated hazard index for the general population was below the maximum limiting value (i.e., 
  3. Radioluminescence sensing of radiology exposures using P-doped silica optical fibres
    Bradley DA, Zubair HT, Oresegun A, Louay GT, Ariffin A, Khandaker MU, et al.
    Appl Radiat Isot, 2018 Nov;141:176-181.
    PMID: 29673719 DOI: 10.1016/j.apradiso.2018.02.025
    In previous work we investigated the real-time radioluminescence (RL) yield of Ge-doped silica fibres and Al2O3 nanodot media, sensing electron- and x-ray energies and intensities at values familiarly obtained in external beam radiotherapy. The observation of an appreciable low-dose sensitivity has given rise to the realisation that there is strong potential for use of RL dosimetry in diagnostic radiology. Herein use has been made of P-doped silica optical fibre, 2 mm diameter, also including a 271 µm cylindrical doped core. With developing needs for versatile x-ray imaging dosimetry, preliminary investigations have been made covering the range of diagnostic x-ray tube potentials 30 kVp to 120 kVp, demonstrating linearity of RL with kVp as well as in terms of the current-time (mAs) product. RL yields also accord with the inverse-square law. Given typical radiographic-examination exposure durations from tens- to a few hundred milliseconds, particular value is found in the ability to record the influence of x-ray generator performance on the growth and decay of beam intensity, from initiation to termination.
  4. Environmental monitoring through use of silica-based TLD
    Rozaila ZS, Khandaker MU, Abdul Sani SF, Sabtu SN, Amin YM, Maah MJ, et al.
    J Radiol Prot, 2017 Sep 25;37(3):761-779.
    PMID: 28581438 DOI: 10.1088/1361-6498/aa770e
    The sensitivity of a novel silica-based fibre-form thermoluminescence dosimeter was tested off-site of a rare-earths processing plant, investigating the potential for obtaining baseline measurements of naturally occurring radioactive materials. The dosimeter, a Ge-doped collapsed photonic crystal fibre (PCFc) co-doped with B, was calibrated against commercially available thermoluminescent dosimetry (TLD) (TLD-200 and TLD-100) using a bremsstrahlung (tube-based) x-ray source. Eight sampling sites within 1 to 20 km of the perimeter of the rare-earth facility were identified, the TLDs (silica- as well as TLD-200 and TLD-100) in each case being buried within the soil at fixed depth, allowing measurements to be obtained, in this case for protracted periods of exposure of between two to eight months. The values of the dose were then compared against values projected on the basis of radioactivity measurements of the associated soils, obtained via high-purity germanium gamma-ray spectrometry. Accord was found in relative terms between the TL evaluations at each site and the associated spectroscopic results. Thus said, in absolute terms, the TL evaluated doses were typically less than those derived from gamma-ray spectroscopy, by ∼50% in the case of PCFc-Ge. Gamma spectrometry analysis typically provided an upper limit to the projected dose, and the Marinelli beaker contents were formed from sieving to provide a homogenous well-packed medium. However, with the radioactivity per unit mass typically greater for smaller particles, with preferential adsorption on the surface and the surface area per unit volume increasing with decrease in radius, this made for an elevated dose estimate. Prevailing concentrations of key naturally occurring radionuclides in soil,226Ra,232Th and40K, were also determined, together with radiological dose evaluation. To date, the area under investigation, although including a rare-earth processing facility, gives no cause for concern from radiological impact. The current study reveals the suitability of the optical fibre based micro-dosimeter for all-weather monitoring of low-level environmental radioactivity.
  5. Radiation induced defects in graphite
    Bradley DA, Ee LS, Mat Nawi SN, Abdul Sani SF, Khandaker M, Alzimami K, et al.
    Appl Radiat Isot, 2022 Feb 10;182:110141.
    PMID: 35180526 DOI: 10.1016/j.apradiso.2022.110141
    We provide retrospective analysis of a consolidated set of confocal Raman microspectrometry and photoluminescence data for irradiated graphitic materials, detecting the generation of low-dose defects. Within the dose range 0.1 Gy-0.2 kGy, one attracting marginal attention in previous radiation damage studies, an effect is seen that potentially seeds material weakening, the pooled data covering independent x-, gamma-rays, and thermal neutron field irradiations. Categorised in terms of a number of key influencing factors, an emergent pattern of response for the various samples under study is observed, indicative of the cycling of radiation driven energy storage and subsequent relaxation. This novel technique, to be referred to herein as defectroscopy, provides a probe of the generation of radiation-induced defects and internal annealing, the strength of the effects being strongly identified to arise from a combination of the ratio of surface area to volume of the samples, fractional carbon content, linear energy transfer, and strain-related defects within the initial material. These examinations offer a first step in considering whether the technique offers wider applicability, not least in early determination of changes in materials with widespread importance in structural and functional roles.
  6. Assessment of breast dose and cancer risk for young females during CT chest and abdomen examinations
    Tamam N, Sulieman A, Omer H, Toufig H, Alsaadi M, Salah H, et al.
    Appl Radiat Isot, 2022 Dec;190:110452.
    PMID: 36183658 DOI: 10.1016/j.apradiso.2022.110452
    CT scanning deliver much higher radiation doses than planar radiological procedures, which puts patients to high risks. This study measures and evaluates patient doses during chest and abdomen computed tomography procedures. Particular attention is given to measuring the dose to the equivalent breast (mSv) and to estimate the associated risks of breast cancer to young female patients (15-35 years). Data was obtained from standard examinations from three hospitals. The measured values of CT dose indexes, CTDI (mGy) as well as exposure-related parameters were used for assessment. Breast and effective doses were extrapolated using a software. The results showed remarkable variations of the mean organ equivalent doses for similar CT examinations in the studied hospitals. This could be attributed to the variation in CT scanning imaging technique, and clinical indications. The average effective dose to the chest was 7.9 mSv (2.3-47.0 mSv) and for the abdomen the mean dose was 6.6 mSv, ranging from (3.3-27 mSv). The breast received equivalent doses from chest and abdomen procedures as follows: 10.2 (1.6-33 mSv) and 10.1(2.3-19 mS) Sv respectively. Each procedure yielded high risks of breast cancer for young females. Implementation of accurate referral criteria is recommended to avoid unnecessary breast radiation exposure.
  7. Photonic crystal fibre as a potential medium for radiotherapy dosimetry
    Begum M, Rahman AKMM, Abdul-Rashid HA, Yusoff Z, Mat Nawi SN, Khandaker MU, et al.
    Appl Radiat Isot, 2021 Aug;174:109771.
    PMID: 34048992 DOI: 10.1016/j.apradiso.2021.109771
    Present study concerns the key thermoluminescence (TL) properties of photonic crystal fibres (PCFs), seeking development of alternatively structured TL materials that are able to offer a advantages over existing passive dosimeters. In terms of their internal structure and light guiding properties the PCFs, collapsed and structured, differ significantly from that of conventional optical fibres. To investigate the dosimetric parameters of the PCFs use was made of a linear accelerator producing a 6 MV photon beam, delivering doses ranging from 0.5 Gy to 8 Gy. The parameters studied included TL response, linearity index, glow curves, relative sensitivity and TL signal fading, the results being compared against those obtained using TLD-100 chips. At 4 Gy photon dose the Ge-doped collapsed PCFs were found to provide a response 27 × that of structured PCF, also giving a TL yield similar to that of standard TLD-100 chips. Over post-irradiation periods of 15 and 30 days collapsed PCF TL signal fading were 8% and 17% respectively, with corresponding values of 37% and 64% for the structured PCF. Trapping parameters including the order of kinetics (b), activation energy (E) and frequency factor (s-1) were assessed with Chen's peak shape method. Lifetime of trapping centre was found to be (2.36 E+03) s and (9.03 E +01) s regarding the collapsed and structured PCF respectively with 6 Gy of photon beam. For the Ge-doped collapsed PCF, the high TL yield, sensitivity and low fading provide the basis of a highly promising system of TLD for radiotherapy applications.
  8. Evaluation of the annual occupational effective doses in a SPECT/CT department
    Aamry A, Sulieman A, Tamam N, Abuhadi NH, Johary Y, Aamri H, et al.
    Appl Radiat Isot, 2022 Mar;181:110097.
    PMID: 35063867 DOI: 10.1016/j.apradiso.2022.110097
    Staff occupational radiation exposure is limited to 20 mSv annually to preclude tissue reaction and lower risk of cancer effect. Staff occupational exposure arises during the preparation, injection, and scanning of the patients. Recent studies reported that nuclear medicine personnel might exceed the annual dose limit in high workload and poor radiation protection circumstances. Therefore, an accurate estimation of the annual dose limit is recommended. The goal of this research is to calculate the cumulative external effective dose (mSv) per year for nuclear medicine physicians, technologists, and nurses at SPECT/CT department. A total of 15 staff worked in the nuclear medicine department at King Saud Medical City (KSMC), Riyadh, Saudi Arabia were evaluated for the last six years. 99mTc is used more frequently for most of the patients. The procedures include renal, cardiac scintigraphy procedures. Staff dose was quantified using calibrated thermoluminecnt dosimeters (TLD-100) with an automatic TLD reader (Harshaw 6600). Exposure to ionizing radiation was evaluated in terms of deep doses (Hp(10) were evaluated. The overall average and standard deviation of the external doses for nuclear medicine physicians, technologists' and nurses were 1.8 ± 0.7, 1.9 ± 0.6, 2.0 ± 0.9, 2.2 ± 0.8, 6.0 ± 2.8, and 3.6 ± 1.3 for the years 2015,2016,2017,2018,2019, and 2020, respectively. Technologists and nurses received higher doses of compared to the nuclear medicine physicians. Technologists and nurses involved in radionuclide preparation, patients' injection, and image acquisition. Staff annual exposure is below the annual dose limits; however, this external dose is considered high compared to the current workload.
  9. Evaluation occupationally radiation exposure during diagnostic imaging examinations
    Johary YH, Albarakati S, AlSohaim A, Aamry A, Aamri H, Tamam N, et al.
    Appl Radiat Isot, 2023 Mar;193:110648.
    PMID: 36669265 DOI: 10.1016/j.apradiso.2023.110648
    Occupational radiation exposure can occur due to various human activities, including the use of radiation in medicine. Occupationally exposed personnel surpassing 7.4 millions, and respresent the biggest single group of employees who are exposed to artificial radiation sources at work. This study compares the occupational radiation dose levels for 145 workers in four different hospitals located in the Aseer region in Saudi Arabia. The occupational exposure was quantified using thermoluminescence dosimeters (TLD-100). The levels of annual occupational exposures in targeted hospitals were calculated and compared with the levels of the international atomic energy agency (IAEA) Safety Standards. An average yearly cumulative dose for the two consecutive years. The average, highest and lowest resulted occupational doses under examination in this work is 1.42, 3.9 mSv and 0.72 for workers in various diagnostic radiology procedures. The resulted annual effective dose were within the IAEA approved yearly dose limit for occupational exposure of workers over 18, which is 20 mSv. Staff should be monitored on a regular basis, according to current practice, because their annual exposure may surpass 15% of the annual effective doses.
  10. Vertical distributions of radionuclides along the tourist-attractive Marayon Tong Hill in the Bandarban district of Bangladesh
    Siraz MMM, Roy D, Dewan MJ, Alam MS, A M J, Rashid MB, et al.
    Environ Monit Assess, 2023 Feb 10;195(3):382.
    PMID: 36759352 DOI: 10.1007/s10661-023-10921-7
    This is the first attempt in the world to depict the vertical distribution of radionuclides in the soil samples along several heights (900 feet, 1550 feet, and 1650 feet) of Marayon Tong hill in the Chittagong Hill Tracts, Bandarban by HPGe gamma-ray spectrometry. The average activity concentrations of 232Th, 226Ra, and 40K were found to be 37.15 ± 3.76 Bqkg-1, 19.69 ± 2.15 Bqkg-1, and 347.82 ± 24.50 Bqkg-1, respectively, where in most cases, 232Th exceeded the world average value of 30 Bqkg-1. According to soil characterization, soils ranged from slightly acidic to moderately acidic, with low soluble salts. The radium equivalent activity, outdoor and indoor absorbed dose rate, external and internal hazard indices, external and internal effective dose rates, gamma level index, and excess lifetime cancer risk were evaluated and found to be below the recommended or world average values; but a measurable activity of 137Cs was found at soils collected from ground level and at an altitude of 1550 feet, which possibly arises from the nuclear fallout. The evaluation of cumulative radiation doses to the inhabitants via periodic measurement is recommended due to the elevated levels of 232Th.This pioneering work in mapping the vertical distribution of naturally occurring radioactive materials (NORMs) can be an essential factual baseline data for the scientific community that may be used to evaluate the variation in NORMs in the future, especially after the commissioning of the Rooppur Nuclear Power Plant in Bangladesh in 2024.
  11. Fulltext Structural Studies of Epithelial Mesenchymal Transition Breast Tissues
    Mohd Sobri SN, Abdul Sani SF, Sabtu SN, Looi LM, Chiew SF, Pathmanathan D, et al.
    Sci Rep, 2020 02 06;10(1):1997.
    PMID: 32029810 DOI: 10.1038/s41598-020-58932-5
    At the supramolecular level, the proliferation of invasive ductal carcinoma through breast tissue is beyond the range of standard histopathology identification. Using synchrotron small angle x-ray scattering (SAXS) techniques, determining nanometer scale structural changes in breast tissue has been demonstrated to allow discrimination between different tissue types. From a total of 22 patients undergoing symptomatic investigations, different category breast tissue samples were obtained in use of surgically removed tissue, including non-lesional, benign and malignant tumour. Structural components of the tissues were examined at momentum transfer values between q = 0.2 nm-1 and 1.5 nm-1. From the SAXS patterns, axial d-spacing and diffuse scattering intensity were observed to provide the greatest discrimination between the various tissue types, specifically in regard to the epithelial mesenchymal transition (EMT) structural component in malignant tissue. In non-lesional tissue the axial period of collagen is within the range 63.6-63.7 nm (formalin fixed paraffin embedded (FFPE) dewaxed) and 63.4 (formalin fixed), being 0.9 nm smaller than in EMT cancer-invaded regions. The overall intensity of scattering from cancerous regions is a degree of magnitude greater in cancer-invaded regions. Present work has found that the d-spacing of the EMT positive breast cancer tissue (FFPE (dewaxed)) is within the range 64.5-64.7 nm corresponding to the 9th and 10th order peaks. Of particular note in regard to formalin fixation of samples is that no alteration is observed to occur in the relative differences in collagen d-spacing between non-lesional and malignant tissues. This is a matter of great importance given that preserved-sample and also retrospective study of samples is greatly facilitated by formalin fixation. Present results indicate that as aids in tissue diagnosis SAXS is capable of distinguishing areas of invasion by disease as well as delivering further information at the supramolecular level.
  12. Fulltext A study on measuring the 222Rn in the Buriganga River and tap water of the megacity Dhaka
    Alam MS, Siraz MMM, A M J, Das SC, Bradley DA, Khandaker MU, et al.
    PLoS One, 2023;18(5):e0286267.
    PMID: 37220107 DOI: 10.1371/journal.pone.0286267
    Radon (222Rn), an inert gas, is considered a silent killer due to its carcinogenic characteristics. Dhaka city is situated on the banks of the Buriganga River, which is regarded as the lifeline of Dhaka city because it serves as a significant source of the city's water supply for domestic and industrial purposes. Thirty water samples (10 tap water from Dhaka city and 20 surface samples from the Buriganga River) were collected and analyzed using a RAD H2O accessory for 222Rn concentration. The average 222Rn concentration in tap and river water was 1.54 ± 0.38 Bq/L and 0.68 ± 0.29 Bq/L, respectively. All the values were found below the maximum contamination limit (MCL) of 11.1 Bq/L set by the USEPA, the WHO-recommended safe limit of 100 Bq/L, and the UNSCEAR suggested range of 4-40 Bq/L. The mean values of the total annual effective doses due to inhalation and ingestion were calculated to be 9.77 μSv/y and 4.29 μSv/y for tap water and river water, respectively. Although all these values were well below the permissible limit of 100 μSv/y proposed by WHO, they cannot be neglected because of the hazardous nature of 222Rn, especially considering their entry to the human body via inhalation and ingestion pathways. The obtained data may serve as a reference for future 222Rn-related works.
  13. Thermoluminescent characterization and defect studies of graphite-rich media under high dose neutron exposure
    Khandaker MU, Nawi SNM, Lam SE, Sani SFA, Islam MA, Islam MA, et al.
    Appl Radiat Isot, 2023 Jun;196:110771.
    PMID: 36933313 DOI: 10.1016/j.apradiso.2023.110771
    Thermoluminescence (TL) materials have a broad variety of uses in various fields, such as clinical research, individual dosimetry, and environmental dosimetry, amongst others. However, the use of individual neutron dosimetry has been developing more aggressively lately. In this regard, present study establishes a relationship between the neutron dosage and the optical property changes of graphite-rich materials caused by high doses of neutron radiation. This has been done with the intention of developing a novel, graphite-based radiation dosimeter. Herein, the TL yield of commercially graphite-rich materials (i.e. graphite sheet, 2B and HB grade pencils) irradiated by neutron radiation with doses ranging from 250 Gy to 1500 Gy has been investigated. The samples were bombarded with thermal neutrons as well as a negligible amount of gamma rays, from the nuclear reactor TRIGA-II installed at the Bangladesh Atomic Energy Commission. The shape of the glow curves was observed to be independent of the given dosage, with the predominant TL dosimetric peak maintained within the region of 163 °C-168 °C for each sample. By studying the glow curves of the irradiated samples, some of the most well theoretical models and techniques were used to compute the kinetic parameters such as the order of kinetics (b), activation energy (E) or trap depth, frequency factor (s) or escape probability, and trap lifetime (τ). All of the samples were found to have a good linear response over the whole dosage range, with 2B grade of polymer pencil lead graphite (PPLGs) demonstrating a higher level of sensitivity than both HB grade and graphite sheet (GS) samples. Additionally, the level of sensitivity shown by each of them is highest at the lowest dosage that was given, and it decreases as the dose increases. Importantly, the phenomenon of dose-dependent structural modifications and internal annealing of defects has been observed by assessing the area of deconvoluted micro-Raman spectra of graphite-rich materials in high-frequency areas. This trend is consistent with the cyclical pattern reported in the intensity ratio of defect and graphite modes in previously investigated carbon-rich media. Such recurrent occurrences suggest the idea of employing Raman microspectroscopy as a radiation damage study tool for carbonaceous materials. The excellent responses of the key TL properties of the 2B grade pencil demonstrate its usefulness as a passive radiation dosimeter. As a consequence, the findings suggest that graphite-rich materials have the potential to be useful as a low-cost passive radiation dosimeter, with applications in radiotherapy and manufacturing.
  14. Fulltext The presence of radioactive heavy minerals in prospecting trenches and concomitant occupational exposure
    Hanfi MYM, Masoud MS, Sayyed MI, Khandaker MU, Faruque MRI, Bradley DA, et al.
    PLoS One, 2021;16(3):e0249329.
    PMID: 33788889 DOI: 10.1371/journal.pone.0249329
    Uranium, perhaps the most strategically important component of heavy minerals, finds particular significance in the nuclear industry. In prospecting trenches, the radioactivity of 238U and 232Th provides a good signature of the presence of heavy minerals. In the work herein, the activity concentrations of several key primordial radionuclides (238U, 232Th, and 40K) were measured in prospecting trenches (each of the latter being of approximately the same geometry and physical situation). All of these are located in the Seila area of the South Eastern desert of Egypt. A recently introduced industry standard, the portable hand-held RS-230 BGO gamma-ray spectrometer (1024 channels) was employed in the study. Based on the measured data, the trenches were classified as either non-regulated (U activity less than 1000 Bq kg-1) or regulated (with 238U activity more than 1000 Bq kg-1). Several radiological hazard parameters were calculated, statistical analysis also being performed to examine correlations between the origins of the radionuclides and their influence on the calculated values. While the radioactivity and hazard parameters exceed United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) guided limits, the mean annual effective doses of 0.49 and 1.4 mSv y-1 in non-regulated and regulated trenches respectively remain well below the International Commission on Radiological Protection (ICRP) recommended 20 mSv/y maximum occupational limit. This investigation reveals that the studied area contains high uranium content, suitable for extraction of U-minerals for use in the nuclear fuel cycle.
  15. Fulltext Elevated Concentrations of Metal(loids) in Seaweed and the Concomitant Exposure to Humans
    Khandaker MU, Chijioke NO, Heffny NAB, Bradley DA, Alsubaie A, Sulieman A, et al.
    Foods, 2021 Feb 10;10(2).
    PMID: 33578933 DOI: 10.3390/foods10020381
    While the consumption of seaweed and seaweed-based products is very common amongst East Asian nations, forming a notable component of the daily diet, relatively very few studies have concerned the concentrations of heavy metals in these together with potential effects on human health. The present study analyses the concentrations of 17 elements in locally resourced seaweed, also assessing potential noncarcinogenic and carcinogenic risks. The samples were ground, homogenized, and quantified using the ICP-OES technique. It has been found that the essential elements K, Ca, Mg, Zn, and Na typically show concentrations somewhat greater than a number of potentially toxic metals, in particular, Cd, Pb, Ag, and As, with exceptions being Ni, Cr-VI, and Si. Statistical analysis indicates all of the latter to have similar origin, with increased concentration of these metals within the marine ecosystem. While the daily estimated intake of most metals is seen to be within the daily dietary allowance level recommended by various international organizations, the noncarcinogenic risk shows a value greater than unity, estimated via the hazard quotient. This indicates a potential for adverse effects to health arising from consumption of the sampled seaweed. The carcinogenic risk resulting from nonessential elements shows values greater than the United States Environmental Protection Agency (US-EPA) reference limit of 10-4. Considering the nonbiodegradability of heavy metals and metalloids and their potential accumulation in seaweed, there is need for critical examination of metal levels in the seaweeds obtained from the present study locations, together with the introduction of practices of removal of heavy metals via bio-adsorbent techniques.
  16. A review: Exploring the metabolic and structural characterisation of beta pleated amyloid fibril in human tissue using Raman spectrometry and SAXS
    Mohd Nor Ihsan NS, Abdul Sani SF, Looi LM, Cheah PL, Chiew SF, Pathmanathan D, et al.
    Prog Biophys Mol Biol, 2023 Sep;182:59-74.
    PMID: 37307955 DOI: 10.1016/j.pbiomolbio.2023.06.002
    Amyloidosis is a deleterious condition caused by abnormal amyloid fibril build-up in living tissues. To date, 42 proteins that are linked to amyloid fibrils have been discovered. Amyloid fibril structure variation can affect the severity, progression rate, or clinical symptoms of amyloidosis. Since amyloid fibril build-up is the primary pathological basis for various neurodegenerative illnesses, characterization of these deadly proteins, particularly utilising optical techniques have been a focus. Spectroscopy techniques provide significant non-invasive platforms for the investigation of the structure and conformation of amyloid fibrils, offering a wide spectrum of analyses ranging from nanometric to micrometric size scales. Even though this area of study has been intensively explored, there still remain aspects of amyloid fibrillization that are not fully known, a matter hindering progress in treating and curing amyloidosis. This review aims to provide recent updates and comprehensive information on optical techniques for metabolic and proteomic characterization of β-pleated amyloid fibrils found in human tissue with thorough literature analysis of publications. Raman spectroscopy and SAXS are well established experimental methods for study of structural properties of biomaterials. With suitable models, they offer extended information for valid proteomic analysis under physiologically relevant conditions. This review points to evidence that despite limitations, these techniques are able to provide for the necessary output and proteomics indication in order to extrapolate the aetiology of amyloid fibrils for reliable diagnostic purposes. Our metabolic database may also contribute to elucidating the nature and function of the amyloid proteome in development and clearance of amyloid diseases.
  17. Fulltext Measurement of radioactivity in soils of Karamjal and Harbaria mangrove forest of Sundarbans for establishment of radiological database
    Siraz MMM, A M J, Alam MS, Rashid MB, Hossain Z, Khandaker MU, et al.
    PLoS One, 2023;18(10):e0289113.
    PMID: 37856554 DOI: 10.1371/journal.pone.0289113
    This work presents the first in-depth study of soil radioactivity in the mangrove forest of Bangladesh part of the Sundarbans. It used HPGe gamma-ray spectrometry to measure the amount of natural radioactivity in soil samples from Karamjal and Harbaria sites of the world's largest mangrove forest. The activity concentrations of most of the 226Ra (14±2 Bqkg-1 to 35±4 Bqkg-1) and 232Th (30±5 Bqkg-1 to 50±9 Bqkg-1) lie within the world average values, but the 40K concentration (370± 44 Bqkg-1 to 660±72 Bqkg-1) was found to have exceeded the world average value. The evaluation of radiological hazard parameters revealed that the outdoor absorbed dose rate (maximum 73.25 nGyh-1) and outdoor annual effective dose (maximum 0.09 mSvy-1) for most samples exceeded the corresponding world average values. The elevated concentration of 40K is mainly due to the salinity intrusion, usage of fertilizers and agricultural runoff, and migration of waste effluents along the riverbanks. Being the pioneering comprehensive research on the Bangladesh side of the Sundarbans, this study forms a baseline radioactivity for the Sundarbans before the commissioning of the Rooppur Nuclear Power Plant in Bangladesh.
  18. Norm in cultivated honey in Malaysia and concomitant effective dose to consumers
    Khandaker MU, Zayadi NSB, Sani SFA, Bradley DA, Osman H, Alzamil Y, et al.
    Radiat Prot Dosimetry, 2023 Nov 02;199(18):2174-2178.
    PMID: 37934995 DOI: 10.1093/rpd/ncad179
    Present study concerns the radiological character of Malaysian honey. A total of 18 samples (representative of the various most common types) were obtained from various honey bee farms throughout the country. Using a high-purity germanium γ-ray spectroscopic system, the samples were analysed for the naturally occurring radionuclides 226Ra, 228Ra and 40K. The respective range of activities (in Bq/kg) was: 3.49 ± 0.35 to 4.51 ± 0.39, 0.99 ± 0.37 to 1.74 ± 0.39 and 41.37 ± 3.26 to 105.02 ± 6.91. The estimated associated committed effective doses were derived from prevailing data on national consumption of honey, the annual dose being found low compared with the UNSCEAR reference dose limit of 290 μSv y-1. The estimated threshold consumption rate for honey indicates a maximum intake of 339 g/d, which poses an insignificant radiological risk to public health; however, the total dietary exposure may not, the guidance level of 290 μSv y-1 being applicable to dietary intake of all foodstuffs. The study is in support of the cultivation of a healthy lifestyle, acknowledging prevailing radioactivity within the environment.
  19. Health-related quality of life in patients with generalized pustular psoriasis: A systematic literature review
    Choon SE, De La Cruz C, Wolf P, Jha RK, Fischer KI, Goncalves-Bradley DC, et al.
    J Eur Acad Dermatol Venereol, 2024 Feb;38(2):265-280.
    PMID: 37750484 DOI: 10.1111/jdv.19530
    Generalized pustular psoriasis (GPP) is a rare, chronic, neutrophilic inflammatory skin disease characterized by episodes of widespread eruption of sterile, macroscopic pustules that can be accompanied by systemic inflammation and symptoms. A systematic literature review and narrative synthesis were conducted to determine the impact of GPP on patients' health-related quality of life (HRQoL) and patient-reported severity of symptoms and to compare its impact to patients with plaque psoriasis (plaque PsO). Searches were undertaken in Embase, MEDLINE and the Cochrane Library from 1 January 2002 to 15 September 2022. Screening was carried out by two reviewers independently. Outcome measures included generic (e.g. EQ-5D, SF-36) and dermatology-specific (e.g. DLQI) clinical outcome assessments, and other relevant patient-reported outcome measures (PROMs) (e.g. severity of pain measured by a numerical rating scale). Overall, 20 studies were found to be eligible for inclusion, of which seven also had data for plaque PsO. The DLQI was the most frequently reported outcome measure (16 out of 20 studies). When reported, mean DLQI (SD) scores varied from 5.7 (1.2) to 15.8 (9.6) across the studies, indicating a moderate to very large effect on HRQoL; the wide range of scores and large SDs were explained by the small population sizes (n ≤ 12 for all studies except two). Similar ranges and large SDs were also observed for other measures within individual studies. However, in general, people with GPP reported a greater impact of their skin condition on HRQoL, when compared to people with plaque PsO (i.e. higher DLQI scores) and higher severity for itch, pain and fatigue. This systematic review highlighted the need for studies with a larger population size, a better understanding of the impact of cutaneous and extracutaneous symptoms and comorbidities on HRQoL during and between GPP flares, and outcome measures specifically tailored to the unique symptoms and the natural course/history of GPP.
  20. EDXRF and the relative presence of K, Ca, Fe and as in amyloidogenic tissues
    Mohd Nor Ihsan NS, Abdul Sani SF, Looi LM, Pathmanathan D, Cheah PL, Chiew SF, et al.
    Spectrochim Acta A Mol Biomol Spectrosc, 2024 Mar 05;308:123743.
    PMID: 38113556 DOI: 10.1016/j.saa.2023.123743
    Trace and minor elements play crucial roles in a variety of biological processes, including amyloid fibrils formation. Mechanisms include activation or inhibition of enzymatic reactions, competition between elements and metal proteins for binding positions, also changes to the permeability of cellular membranes. These may influence carcinogenic processes, with trace and minor element concentrations in normal and amyloid tissues potentially aiding in cancer diagnosis and etiology. With the analytical capability of the spectroscopic technique X-ray fluorescence (XRF), this can be used to detect and quantify the presence of elements in amyloid characterization, two of the trace elements known to be associated with amyloid fibrils. In present work, involving samples from a total of 22 subjects, samples of normal and amyloid-containing tissues of heart, kidney, thyroid, and other tissue organs were obtained, analyzed via energy-dispersive X-ray fluorescence (EDXRF). The elemental distribution of potassium (K), calcium (Ca), arsenic (As), and iron (Fe) was examined in both normal and amyloidogenic tissues using perpetual thin slices. In amyloidogenic tissues the levels of K, Ca, and Fe were found to be less than in corresponding normal tissues. Moreover, the presence of As was only observed in amyloidogenic samples; in a few cases in which there was an absence of As, amyloid samples were found to contain Fe. Analysis of arsenic in amyloid plaques has previously been difficult, often producing contradictory results. Using the present EDXRF facility we could distinguish between amyloidogenic and normal samples, with potential correlations in respect of the presence or concentration of specific elements.
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