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Fulltext Thermal Properties and Drying Shrinkage Performance of Palm Kernel Shell Ash and Rice Husk Ash-Based Geopolymer Concrete

Abdullah MN, Mustapha F, Yusof N', Khan T, Sebaey TA

Materials (Basel), 2024 Mar 11;17(6).
PMID: 38541452 DOI: 10.3390/ma17061298

This study aims to develop suitable formulations of geopolymer concrete (GPC) by varying the percentages of the geopolymer with aggregates and evaluating the performances in thermal and mechanical properties of palm kernel shell ash (PKSA)-GPC compared to rice husk ash (RHA)-GPC and ordinary Portland cement concrete (OPCC). Preliminary tests were conducted to select the best mix design ratios before casting the specimens. Then, the performance of the PKSA-GPC, RHA-GPC and OPCC specimens was evaluated based on their thermal performance and drying shrinkage. The mix designs of PKSA-GPC 70:30, PKSA-GPC 60:40, PKSA-GPC 50:50 and PKSA-GPC 66.6:33.3 were found to produce an acceptable consistency, rheological and thixotropic behaviour for the development of the GPC. PKSA-GPC showed a better thermal performance than the RHA-GPC and OPCC due to their strong and dense intumescent layers and slow temperature increment upon exposure to a high flame temperature from ambient temperature to 169 °C. The low molar ratio of the Si/Al present in the PKSA-GPC created a thermally stable intumescent layer. In the drying shrinkage test, PKSA-GPC 60:40 and RHA-GPC 60:40 shared an equal drying shrinkage performance (5.040%) compared to the OPCC (8.996%). It was observed that microcrack formation could significantly contribute to the high shrinkage in the PKSA-GPC 50:50 and RHA-GPC 70:30 specimens. The findings of this study show that PKSA could be incorporated into GPC as a fire-retardant material due to its capability of prolonging the spread of fire upon ignition and acting as an alternative to the conventional OPCC.
Harnessing the photocatalytic potential of bismuth ferrite-activated carbon nanocomposite (BFO-AC) for Staphylococcus aureus decontamination under visible light

Daub NA, Aziz F, Mhamad SA, Chee DNA, Jaafar J, Yusof N, et al.

Environ Sci Pollut Res Int, 2024 Mar;31(11):16629-16641.
PMID: 38321283 DOI: 10.1007/s11356-024-32261-w

In response to the escalating global issue of microbial contamination, this study introduces a breakthrough photocatalyst: bismuth ferrite-activated carbon (BFO-AC) for visible light-driven disinfection, specifically targeting the Gram-positive bacterium Staphylococcus aureus (S. aureus). Employing an ultrasonication method, we synthesized various BFO-AC ratios and subjected them to comprehensive characterization. Remarkably, the bismuth ferrite-activated carbon 1:1.5 ratio (BA 1:1.5) nanocomposite exhibited the narrowest band gap of 1.86 eV. Notably, BA (1:1.5) demonstrated an exceptional BET surface area of 862.99 m2/g, a remarkable improvement compared to pristine BFO with only 27.61 m2/g. Further investigation through FE-SEM unveiled the presence of BFO nanoparticles on the activated carbon surface. Crucially, the photocatalytic efficacy of BA (1:1.5) towards S. aureus reached its zenith, achieving complete inactivation in just 60 min. TEM analysis revealed severe damage and rupture of bacterial cells, affirming the potent disinfection capabilities of BA (1:1.5). This exceptional disinfection efficiency underscores the promising potential of BA (1:1.5) for the treatment of contaminated water sources. Importantly, our results underscore the enhanced photocatalytic performance with an increased content of activated carbon, suggesting a promising avenue for more effective microorganism inactivation.
Virtual counselling of tobacco cessation during the COVID-19 pandemic: A qualitative study on the experiences and perceptions of Malaysian dental undergraduates and their patients

Roslan N, Yusof N, Md Bohari NF, Md Sabri BA, Mohd Radzi NA, Bakri NN, et al.

Eur J Dent Educ, 2024 Feb;28(1):28-40.
PMID: 37132218 DOI: 10.1111/eje.12912

INTRODUCTION: When dental institutions had to close down during the Movement Control Order (MCO) implementation due to the COVID-19 pandemic, dental students were faced with delays in completing their tobacco cessation schedule. An alternative was to allow students to conduct virtual counselling (VC) for smoking cessation for their patients to address their clinical requirements. This study aimed to explore Malaysian dental undergraduates' and patients' experiences undergoing smoking cessation counselling through virtual platforms.
MATERIALS AND METHODS: The study consisted of qualitative, semi-structured Focus Group Discussions (for students, n = 23) and in-depth interviews (for patients, n = 9); to phenomenologically describe the perceptions of participants involved in the VC. Each session was recorded with the participants' permission. The recorded session was transcribed verbatim and thematically analysed using the qualitative data analysis software, NVivo™.
RESULTS: The major themes that emerged were: (1) General opinions and experiences, (2) Content of VCs, (3) Remote access to counselling, (4) Patient-clinician relationships, (5) Technical issues, (6) Changes after VCs, and (7) Future application. Most students and patients were quite comfortable with VC as it is convenient, allowing students to be creative and avoid the hassle of transport and traffic. However, some of the students felt that it lacked the personal touch and guidance from lecturers who would normally be present during physical class.
CONCLUSION: Virtual counselling enables remote access to counselling, but it is also subjected to some limitations, especially regarding lack of clinical assessments, human touch and internet issues. Though participants were optimistic about adapting it in the future, multiple factors must be considered. Ultimately, the behavioural change will depend on the patient's motivation in making a difference.
Components in downstream health promotions to reduce sugar intake among adults: a systematic review

Azhar Hilmy SH, Nordin N, Yusof MYPM, Soh TYT, Yusof N

Nutr J, 2024 Jan 17;23(1):11.
PMID: 38233923 DOI: 10.1186/s12937-023-00884-3

Excessive sugar consumption is well documented as a common risk factor for many Non-Communicable Diseases (NCDs). Thus, an adequate intervention description is important to minimise research waste and improve research usability and reproducibility. A systematic review was conducted to identify components in published evidence interventions pertaining to the health promotions on reducing sugar intake among adults. The review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and used the Mixed Methods Appraisal Tool (MMAT) for quality appraisal. The period for the selected study was from 2000 to 2022, and articles were retrieved from Web of Science (WOS), Medline, Scopus, and PubMed. The target population was adults aged 18 years old and above who underwent intervention to assess the changes in their sugar intake. Data sources and all human epidemiologic studies were included. Out of the 9,333 papers identified, 25 were included. The overall quality of evidence of the studies was considered moderate. Apart from the characteristics of the reviewed studies, components of interventions are including the basis of theoretical or model for the intervention, which majority use Social Cognitive Theory, followed by PRECEDE-PROCEED model, socio-ecological and process-improvement theories and Transtheoretical Model; providers, who are commercial provider, qualified nutritionist, professor of nutrigenomics and nutrigenetics, doctor, dietitian nutritionist, lifestyle coaches, and junior public health nurses; duration of the intervention and follow-up time, varies from as short as one month to as long as 24 months; material provided either softcopy or hardcopy; tailoring approach, based on the individual goals, the process of change, genotype analysis, beliefs, barriers, and sociocultural norms; delivery mechanism either face-to-face or technology-mediated; and tools to measure the sugar consumption outcome mostly used Food Frequency Questionnaire (FFQ), besides 24-h dietary recalls, and food diaries. There are various components in downstream health promotion to reduce sugar intake among adults that can be adapted according to the local health promotion and intervention context. More well-designed interventions using integration components are encouraged in further studies.
Online commentaries of the sugar-sweetened beverages tax in Malaysia: Content analysis

Mohd Hanim MFB, Md Sabri BA, Yusof N

Public Health Nurs, 2024;41(1):139-150.
PMID: 37953703 DOI: 10.1111/phn.13262

INTRODUCTION: Implementing taxes on sugary drinks, or SSBs, has been a controversial topic in many countries, including Malaysia. This study aimed to examine how Malaysian Facebook users responded to the announcement and implementation of the SSBs tax through netnography.
METHODS: This cross-sectional study employed qualitative and quantitative methods and used an inductive approach and thematic content analysis to analyze online commentaries on news articles published on popular online news portals from November 2018 to August 2019. Data was collected by downloading the commentaries onto Microsoft Word and importing them into NVivo.
RESULTS: Of the commentaries analyzed, 60.9% rejected the SSBs tax, and 39.1% favored it. No association was found between the online news articles and the slants of the commentaries.
CONCLUSION: The results of this study demonstrate a clear divide in public opinion regarding the SSBs tax in Malaysia, with many online readers expressing opposition to the tax despite evidence of the harmful effects of sugar presented in the articles they are commenting on. These findings have implications for policymakers and public health advocates seeking to implement similar taxes in the future.
Fulltext Parity and housing effects on the behavioural and hypothalamic-pituitary-adrenal axis responses of pregnant ewes

Yusof NNM, Rutherford KMD, Jarvis S, Valente L, Dwyer CM

Animal, 2023 Nov;17(11):101006.
PMID: 37897868 DOI: 10.1016/j.animal.2023.101006

It is common in many countries for sheep to be housed during winter from mid-gestation until lambing to protect ewes and lambs from adverse conditions and improve late gestation nutritional management. Keeping ewes indoors, however, has its own challenges as the animals may be mixed with unfamiliar conspecifics, have limited floor and feeding space, experience changes to their diet and increased handling by humans. Therefore, the objective of this study was to investigate the effect of variation in housing management (space allowance and social stability) on the behaviour and hypothalamic-pituitary-adrenal (HPA) axis responses of pregnant ewes from mid-to-late gestation (weeks 11-18 of pregnancy). Seventy-seven ewes (41 primiparous, 36 multiparous) were divided into two groups: 'Control' and 'Restricted space and mixed' (RS-Mix), where RS-Mix ewes were allocated half the amount of space (1.27 vs 2.5 m2 for RS-Mix and Control, respectively) and feedface (concentrate feeder space) allowance (36 vs 71 cm per ewe) given to the Control group and were also subjected to two social mixing events. Aggressive behaviour at the feedface and time spent standing, lying, walking, feeding and ruminating were recorded and faecal samples were collected for assessment of faecal glucocorticoid metabolite (FGM) concentrations. Higher aggression was observed in RS-Mix ewes during the first week of observation (P = 0.044), which gradually declined to the same level as Control ewes by the end of the study (P = 0.045). RS-Mix ewes were significantly less likely to be able to freely join the feedface compared to Controls (P = 0.022). No other significant treatment effects on aggressive behaviour or FGM during gestation were found. RS-Mix ewes displayed significantly higher ruminating behaviour at week 18 of gestation compared to Control ewes (P
Assessing sequence heterogeneity in Chlorellaceae DNA barcode markers for phylogenetic inference

Wong EB, Kamaruddin N, Mokhtar M, Yusof N, Khairuddin RFR

J Genet Eng Biotechnol, 2023 Oct 18;21(1):104.
PMID: 37851281 DOI: 10.1186/s43141-023-00550-5

Phylogenetic inference is an important approach that allows the recovery of the evolutionary history and the origin of the Chlorellaceae species. Despite the species' potential for biofuel feedstock production, their high phenotypic plasticity and similar morphological structures among the species have muddled the taxonomy and identification of the Chlorellaceae species. This study aimed to decipher Chlorellaceae DNA barcode marker heterogeneity by examining the sequence divergence and genomic properties of 18S rRNA, ITS (ITS1-5.8S rRNA-ITS2-28S rRNA), and rbcL from 655 orthologous sequences of 64 species across 31 genera in the Chlorellaceae family. The study assessed the distinct evolutionary properties of the DNA markers that may have caused the discordance between individual trees in the phylogenetic inference using the Robinson-Foulds distance and the Shimodaira-Hasegawa test. Our findings suggest that using the supermatrix approach improves the congruency between trees by reducing stochastic error and increasing the confidence of the inferred Chlorellaceae phylogenetic tree. This study also found that the phylogenies inferred through the supermatrix approach might not always be well supported by all markers. The study highlights that assessing sequence heterogeneity prior to the phylogenetic inference could allow the approach to accommodate sequence evolutionary properties and support species identification from the most congruent phylogeny, which can better represent the evolution of Chlorellaceae species.
Fulltext A Rare Case of Salter-Harris Type I Growth Plate Injury in a Patient Undergoing Limb-Lengthening Procedure

Esmat SM, Sulong AF, Awang MS, Oon ZS, Mohd Yusof N

Cureus, 2023 Aug;15(8):e43448.
PMID: 37711923 DOI: 10.7759/cureus.43448

Growth plate injuries over the distal femur typically occur due to high-energy trauma. It is commonly associated with serious complications such as growth disturbance. Its occurrence in children undergoing limb-lengthening procedures is uncommon. We report a case of distal femur growth plate injury in a 13-year-old boy undergoing a limb-lengthening procedure for femoral hypoplasia. Conservative treatment yielded a good functional outcome in this patient.
Fulltext Recent Development of Nanocomposite Membranes for Water and Wastewater Treatment

Ismail AF, Goh PS, Yusof N

Nanomaterials (Basel), 2023 May 20;13(10).
PMID: 37242102 DOI: 10.3390/nano13101686

The field of membrane technology has experienced significant growth in recent years, especially in the areas of wastewater treatment and desalination [...].
Fulltext Antimicrobial resistance in methicillin-resistant staphylococcus aureus

Ali Alghamdi B, Al-Johani I, Al-Shamrani JM, Musamed Alshamrani H, Al-Otaibi BG, Almazmomi K, et al.

Saudi J Biol Sci, 2023 Apr;30(4):103604.
PMID: 36936699 DOI: 10.1016/j.sjbs.2023.103604

In the medical community, antibiotics are revered as a miracle because they stop diseases brought on by pathogenic bacteria. Antibiotics have become the cornerstone of contemporary medical advancements ever since penicillin was discovered. Antibiotic resistance developed among germs quickly, placing a strain in the medical field. Methicillin-resistant Staphylococcus aureus (MRSA), Since 1961, has emerged as the major general antimicrobial resistant bacteria (AMR) worldwide. MRSA can easily transmit across the hospital system and has mostly gained resistance to medications called beta-lactamases. This enzyme destroys the cell wall of beta-lactam antibiotics resulting in resistance against that respective antibiotic. Daptomycin, linezolid and vancomycin were previously used to treat MRSA infections. However, due to mutations and Single nucleotide polymorphisms (SNPs) in Open reading frames (ORFs) and SCCmec machinery of respective antibody, MRSA developed resistance against those antibiotics. The MRSA strains (USA300, CC398, CC130 etc.), when their pan-genomes were analyzed were found the genes involved in invoking resistance against the antibiotics as well as the epidemiology of that respective strain. PENC (penicillin plus potassium clavulanate) is the new antibiotic showing potential in treatment of MRSA though it is itself resistant against penicillin alone. In this review, our main focus is on mechanism of development of AMR in MRSA, how different ORFs are involved in evoking resistance in MRSA and what is the core-genome of different antimicrobial resistant MRSA.
Effects of processing and gamma radiation on mechanical properties and organic composition of frozen, freeze-dried and demineralised human cortical bone allograft

Mansor A, Ariffin AF, Yusof N, Mohd S, Ramalingam S, Md Saad AP, et al.

Cell Tissue Bank, 2023 Mar;24(1):25-35.
PMID: 35610332 DOI: 10.1007/s10561-022-10013-9

Bone processing and radiation were reported to influence mechanical properties of cortical bones due in part to structural changes and denaturation of collagen composition. This comparative study was to determine effects of bone processing on mechanical properties and organic composition, and to what extent the radiation damaging after each processing. Human femur cortical bones were processed by freezing, freeze-drying and demineralisation and then gamma irradiated at 5, 15, 20, 25 and 50 kGy. In the compression test, freeze drying significantly decreased the Young's Modulus by 15%, while demineralisation reduced further by 90% (P
A novel nonlinear time-varying sigmoid transfer function in binary whale optimization algorithm for descriptors selection in drug classification

Mohd Yusof N, Muda AK, Pratama SF, Abraham A

Mol Divers, 2023 Feb;27(1):71-80.
PMID: 35254585 DOI: 10.1007/s11030-022-10410-y

In computational chemistry, the high-dimensional molecular descriptors contribute to the curse of dimensionality issue. Binary whale optimization algorithm (BWOA) is a recently proposed metaheuristic optimization algorithm that has been efficiently applied in feature selection. The main contribution of this paper is a new version of the nonlinear time-varying Sigmoid transfer function to improve the exploitation and exploration activities in the standard whale optimization algorithm (WOA). A new BWOA algorithm, namely BWOA-3, is introduced to solve the descriptors selection problem, which becomes the second contribution. To validate BWOA-3 performance, a high-dimensional drug dataset is employed. The proficiency of the proposed BWOA-3 and the comparative optimization algorithms are measured based on convergence speed, the length of the selected feature subset, and classification performance (accuracy, specificity, sensitivity, and f-measure). In addition, statistical significance tests are also conducted using the Friedman test and Wilcoxon signed-rank test. The comparative optimization algorithms include two BWOA variants, binary bat algorithm (BBA), binary gray wolf algorithm (BGWOA), and binary manta-ray foraging algorithm (BMRFO). As the final contribution, from all experiments, this study has successfully revealed the superiority of BWOA-3 in solving the descriptors selection problem and improving the Amphetamine-type Stimulants (ATS) drug classification performance.
A Prospective Multicenter Randomized Controlled Trial to Evaluate the Efficacy of Chitosan Hydrogel Paste in Comparison to Commercial Hydroactive Gel as a Wound Bed Preparation

Nasir NAM, Saad AZM, Bachok NS, Rashid AHA, Ujang Z, Noorsal K, et al.

Indian J Plast Surg, 2023 Feb;56(1):44-52.
PMID: 36998939 DOI: 10.1055/s-0042-1759503

Background This clinical trial aimed to evaluate the clinical efficacy of chitosan derivative hydrogel paste (CDHP) as a wound bed preparation for wounds with cavities. Methods This study enrolled 287 patients, with 143 patients randomized into the CDHP group (treatment) and 144 patients randomized into the commercial hydroactive gel (CHG) group (control). The granulation tissue, necrotic tissue, patient comfort, clinical signs, symptoms, and patient convenience during the application and removal of the dressing were assessed. Results The study was completed by 111 and 105 patients from the treatment and control groups, respectively. Both groups showed an increasing mean percentage of wound granulation over time when the initial wound size and comorbidity were adjusted (F(10,198) = 4.61; p
Fulltext Optical reflectometric measurement of SARS-CoV-2 (COVID-19) RNA based on cationic cysteamine-capped gold nanoparticles

Diyana Jamaluddin N, Ibrahim N, Yuziana Mohd Yusof N, Ta Goh C, Ling Tan L

Opt Laser Technol, 2023 Jan;157:108763.
PMID: 36212170 DOI: 10.1016/j.optlastec.2022.108763

The coronavirus disease (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged as a major public health outbreak in late 2019 and was proclaimed a global pandemic in March 2020. A reflectometric-based RNA biosensor was developed by using cysteamine-stabilized gold nanoparticles (cysAuNPs) as the colorimetric probe for bioassay of COVID-19 RNA (SARS-CoV-2 RNA) sequence. The cysAuNPs aggregated in the presence of DNA probes via cationic and anionic electrostatic attraction between the positively charged cysteamine ligands and the negatively charged sugar-phosphate backbone of DNA, whilst in the presence of target RNAs, the specific recognition between DNA probes and targets depleted the electrostatic interaction between the DNA probes and cysAuNPs signal probe, leading to dispersed particles. This has rendered a remarkable shifting in the surface plasmon resonance (SPR) on the basis of visual color change of the RNA biosensor from red to purplish hue at the wavelength of 765 nm. Optical evaluation of SARS-CoV-2 RNA by means on reflectance transduction of the RNA biosensor based on cysAuNPs optical sensing probes demonstrated rapid response time of 30 min with high sensitivity, good linearity and high reproducibility across a COVID-19 RNA concentration range of 25 nM to 200 nM, and limit of detection (LOD) at 0.12 nM. qPCR amplification of SARS-CoV-2 viral RNA showed good agreement with the proposed RNA biosensor by using spiked RNA samples of the oropharyngeal swab from COVID-19 patients. Therefore, this assay is useful for rapid and early diagnosis of COVID-19 disease including asymptomatic carriers with low viral load even in the presence of co-infection with other viruses that manifest similar respiratory symptoms.
Fulltext Emotional Intelligence, Depression, Stress and Anxiety Amongst Undergraduate Dental Students During the COVID-19 Pandemic

Dasor MM, Jafridin AA, Azhar AA, Asma AAA, Manivannan PC, Bilal S, et al.

Int J Public Health, 2023;68:1604383.
PMID: 36846156 DOI: 10.3389/ijph.2023.1604383

Objectives: This study aimed to measure depression, anxiety and stress (DAS) among undergraduate dental students during the COVID-19 pandemic, identify key contributing factors of stress and explore the association of emotional intelligence to DAS. Methods: A multi-centre, cross-sectional study was conducted across four universities in Malaysia. The study administered a questionnaire consisting of the validated Depression Anxiety Stress Scale (DASS), Dental Environment Stress (DES), Emotional Intelligence Scale (EI) and 10 statements assessing COVID-19 specific potential stressor factors. Results: Participants included 791 students across four universities. Abnormal levels of DAS were identified in 60.6%, 66.8% and 42.6% of the study participants, respectively. "Pressure of performance," "Faculty administration" and "Self-efficacy belief" were the highest rated stressors. On-time graduation was the main COVID-19 specific stressor factor. EI was negatively correlated with DAS scores (p < 0.001). Conclusion: The levels of DAS during COVID-19 pandemic in this population is high. However, participants with higher EI presented with lower DAS suggesting that EI may be a form of coping resource and should be enhanced in this population.
Effect of energy management and waste management on schedule performance: role of technological complexity and project size

Onubi HO, Yusof N, Hassan AS, Bahdad AAS

Environ Sci Pollut Res Int, 2022 Apr;29(19):29075-29090.
PMID: 34993828 DOI: 10.1007/s11356-021-18376-4

Schedule overrun is one of the greatest hindrances to construction project performance, thereby making schedule management an integral part of construction project management. The aim of this study is to examine how the effect of sustainable energy management (SEM) and sustainable waste management (SWM) on schedule performance (SP) is mediated by technological complexity (TC) and moderated by project size (PS). Data were obtained by means of a questionnaire survey of 168 completed construction projects in Nigeria. The partial least squares structural equation modelling (PLS-SEM) technique was adopted in analysing the collected data. The results show that TC partially mediates the relationship between SWM and SP, while TC fully mediates the relationship between SEM and SP. Also, the findings of the study indicate that the negative effect of SWM on SP will be greater with large PS. This study contributes to previous studies in the area of schedule management, by providing empirical proof to explain the means through which SWM and SEM could lead to SP through TC, and how this would vary depending on PS. The study proffers ways for contractors to improve the SP of their projects considering PS and TC.
Fulltext A review of the potential of conventional and advanced membrane technology in the removal of pathogens from wastewater

Nasir AM, Adam MR, Mohamad Kamal SNEA, Jaafar J, Othman MHD, Ismail AF, et al.

Sep Purif Technol, 2022 Apr 01;286:120454.
PMID: 35035270 DOI: 10.1016/j.seppur.2022.120454

Consumption of pathogenic contaminated water has claimed the lives of many people. Hence, this scenario has emphasized the urgent need for research methods to avoid, treat and eliminate harmful pathogens in wastewater. Therefore, effective water treatment has become a matter of utmost importance. Membrane technology offers purer, cleaner, and pathogen-free water through the water separation method via a permeable membrane. Advanced membrane technology such as nanocomposite membrane, membrane distillation, membrane bioreactor, and photocatalytic membrane reactor can offer synergistic effects in removing pathogen through the integration of additional functionality and filtration in a single chamber. This paper also comprehensively discussed the application, challenges, and future perspective of the advanced membrane technology as a promising alternative in battling pathogenic microbial contaminants, which will also be beneficial and valuable in managing pandemics in the future as well as protecting human health and the environment. In addition, the potential of membrane technology in battling the ongoing global pandemic of coronavirus disease 2019 (COVID-19) was also discussed briefly.
Fulltext Deep-Freezing Temperatures During Irradiation Preserves the Compressive Strength of Human Cortical Bone Allografts: A Cadaver Study

Yang Harmony TC, Yusof N, Ramalingam S, Baharin R, Syahrom A, Mansor A

Clin Orthop Relat Res, 2022 Feb 01;480(2):407-418.
PMID: 34491235 DOI: 10.1097/CORR.0000000000001968

BACKGROUND: Gamma irradiation, which minimizes the risk of infectious disease transmission when human bone allograft is used, has been found to negatively affect its biomechanical properties. However, in those studies, the deep-freezing temperature during irradiation was not necessarily maintained during transportation and sterilization, which may have affected the findings. Prior reports have also suggested that controlled deep freezing may mitigate the detrimental effects of irradiation on the mechanical properties of bone allograft.
QUESTION/PURPOSE: Does a controlled deep-freezing temperature during irradiation help preserve the compressive mechanical properties of human femoral cortical bone allografts?
METHODS: Cortical bone cube samples, each measuring 64 mm3, were cut from the mid-diaphyseal midshaft of five fresh-frozen cadaver femurs (four male donors, mean [range] age at procurement 42 years [42 to 43]) and were allocated via block randomization into one of three experimental groups (with equal numbers of samples from each donor allocated into each group). Each experimental group consisted of 20 bone cube samples. Samples irradiated in dry ice were subjected to irradiation doses ranging from 26.7 kGy to 27.1 kGy (mean 26.9 kGy) at a deep-freezing temperature below -40°C (the recommended long-term storage temperature for allografts). Samples irradiated in gel ice underwent irradiation doses ranging from 26.2 kGy and 26.4 kGy (mean 26.3 kGy) in a freezing temperature range between -40°C and 0°C. Acting as controls, samples in a third group were not subjected to gamma irradiation. The mechanical properties (0.2% offset yield stress, ultimate compression stress, toughness, and the Young modulus) of samples from each group were subsequently evaluated via axial compression loading to failure along the long axis of the bone. The investigators were blinded to sample group during compression testing.
RESULTS: The mean ultimate compression stress (84 ± 27 MPa versus 119 ± 31 MPa, mean difference 35 [95% CI 9 to 60]; p = 0.005) and toughness (3622 ± 1720 kJ/m3 versus 5854 ± 2900 kJ/m3, mean difference 2232 [95% CI 70 to 4394]; p = 0.009) of samples irradiated at a higher temperature range (-40°C to 0°C) were lower than in those irradiated at deep-freezing temperatures (below -40°C). The mean 0.2% offset yield stress (73 ± 28 MPa versus 109 ± 38 MPa, mean difference 36 [95% CI 11 to 60]; p = 0.002) and ultimate compression stress (84 ± 27 MPa versus 128 ± 40 MPa, mean difference 44 [95% CI 17 to 69]; p < 0.001) of samples irradiated at a higher temperature range (-40°C to 0°C) were lower than the nonirradiated control group samples. The mean 0.2% offset yield stress (73 ± 28 MPa versus 101 ± 28 MPa, mean difference 28 [95% CI 3 to 52]; p = 0.02; effect size = 1.0 [95% CI 0.8 to 1.2]) of samples irradiated at higher temperature range (-40°C to 0°C) were no different with the numbers available to those irradiated at deep-freezing temperature. The mean toughness (3622 ± 1720 kJ/m3 versus 6231 ± 3410 kJ/m3, mean difference 2609 [95% CI 447 to 4771]; p = 0.02; effect size = 1.0 [95% CI 0.8 to 1.2]) of samples irradiated at higher temperature range (-40°C to 0°C) were no different with the numbers available to the non-irradiated control group samples. The mean 0.2% offset yield stress, ultimate compression stress, and toughness of samples irradiated in deep-freezing temperatures (below -40°C) were not different with the numbers available to the non-irradiated control group samples. The Young modulus was not different with the numbers available among the three groups.
CONCLUSION: In this study, maintenance of a deep-freezing temperature below -40°C, using dry ice as a cooling agent, consistently mitigated the adverse effects of irradiation on the monotonic-compression mechanical properties of human cortical bone tissue. Preserving the mechanical properties of a cortical allograft, when irradiated in a deep-freezing temperature, may have resulted from attenuation of the deleterious, indirect effects of gamma radiation on its collagen architecture in a frozen state. Immobilization of water molecules in this state prevents radiolysis and the subsequent generation of free radicals. This hypothesis was supported by an apparent loss of the protective effect when a range of higher freezing temperatures was used during irradiation.
CLINICAL RELEVANCE: Deep-freezing temperatures below -40°C during gamma irradiation may be a promising approach to better retain the native mechanical properties of cortical bone allografts. A further study of the effect of deep-freezing during gamma radiation sterilization on sterility and other important biomechanical properties of cortical bone (such as, tensile strength, fracture toughness, and fatigue) is needed to confirm these findings.
Fulltext Rare but Potentially Fatal Presentations of Diffuse Large B-cell Lymphoma: Leukemic Phase or Hemophagocytic Syndrome in Bone Marrow

Wan Mohd Zohdi WA, Ismail AZ, Yusof N, Ithnin A, Shuib S, Masir N, et al.

Clin Pathol, 2022 01 09;15:2632010X211070774.
PMID: 35036912 DOI: 10.1177/2632010X211070774

Diffuse large B-cell lymphoma (DLBCL) is a type of non-Hodgkin Lymphoma commonly presenting as a solid tumor either by nodal or extra-nodal manifestations. Here we describe two atypical presentations of lymphoma, finally resulting in the diagnosis of DLBCL. Case 1: A 53-year-old man with a previous history of nasopharyngeal carcinoma presented with a two-week history of B-symptoms and hyperleukocytosis. Peripheral blood film showed 78% abnormal mononuclear cells. Immunohistochemical stain showing Ki-67 of 90%, negative c-myc, BCL2 and BCL6, and negative c-MYC with fluorescence in-situ hybridization studies on the trephine biopsy, concluded the diagnosis of CD5+ DLBCL of ABC subtype. He received intravenous cyclophosphamide and oral prednisolone for cytoreduction, followed by 6 cycles of chemo-immunotherapy. However, he succumbed due to severe sepsis after the completion of therapy. Case 2: A 56-year-old lady who was initially investigated for pyrexia of unknown origin was noted to have hemophagocytosis upon bone marrow aspirate examination. The bone marrow trephine biopsy revealed some atypical clusters of B-cells positive for CD20 which was inconclusive. PET-CT scan noted an enlarged hypermetabolic spleen without lymphadenopathy. Splenic biopsy with immunohistochemical studies revealed DLBCL of ABC subtype. The diagnosis was consistent with primary splenic DLBCL. She became unwell post splenic biopsy and was admitted to the intensive care unit where she passed away 2 weeks later from Candida and Sternotrophomonas septicemia. These cases highlight the atypical presentations of a common subtype of NHL in our center. Arriving at the definitive diagnosis can be difficult especially when patients are acutely ill, hampering the necessary invasive procedures for diagnosis. The outcomes of both cases are briefly discussed hoping to spread awareness among clinicians on the rare and acutely critical presentations of DLBCL.
Green construction practices: ensuring client satisfaction through health and safety performance

Onubi HO, Yusof N, Hassan AS

Environ Sci Pollut Res Int, 2022 Jan;29(4):5431-5444.
PMID: 34420175 DOI: 10.1007/s11356-021-15705-5

Studies have proven that client satisfaction (CS) is greatly affected by the nature of construction practices on site. However, not much attention has been given to CS in projects that adopt green construction practices (GCPs). This study examines the effect of GCPs on CS, and the means by which CS can be achieved through health and safety performance (HSP). This study also analyses how the relationship between HSP and CS could vary depending on the level of GCPs adopted. A questionnaire with 27 items drawn from literature was used in collecting data from class A contractors in Nigeria. The study's hypotheses were tested using the partial least squares structural equation modelling (PLS-SEM) technique. The findings of the study reveal that GCPs have a positive effect on CS. HSP proved to only partially mediate the relationship between GCPs and CS. The findings also show that the effect of HSP on CS is moderated by GCPs with the stronger effect from projects with low adoption of GCPs. The study's findings highlight the pivotal role of HSP in ensuring CS in construction projects that adopt GCPs. This study makes practical contributions to the body of existing knowledge by highlighting the need for concerted efforts by contractors such as investing in health and safety training and ensuring site workers wear personal protective equipment aimed at adhering to acceptable health and safety standards. This can be achieved through provision of funds for safety activities, monitoring, and supervision of workers to guarantee HSP which translates to CS while adopting GCPs. However, the obstacles to these are the lack of safety culture by construction organizations, lack of enlightenment on the part of construction site workers, and poor safety climate on the construction project site. Additionally, the study provides greater insight on the practice of green construction among contractors by showing that the effect of HSP on CS would differ considerably on account of the level of GCPs adopted.

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