Browse publications by year: 2021

Numerical model for enhancing stimulated Brillouin scattering in optical microfibers

Yeap SH, Emami SD, Abdul-Rashid HA

F1000Res, 2021;10:521.
PMID: 37745939 DOI: 10.12688/f1000research.51029.2

Stimulated Brillouin scattering (SBS) is useful, among others for generating slow light, sensing and amplification. SBS was previously viewed as a poor method due to the limitation on optical power in high-powered photonic applications. However, considering the many possible applications using SBS, it is now of interest to enhance SBS in areas of Brillouin frequency shift together with Brillouin Gain. A numerical model, using a fully vectorial approach, by employing the finite element method, was developed to investigate methods for enhancing SBS in optical fiber. This paper describes the method related to the numerical model and discusses the analysis between the interactions of longitudinal, shear and hybrid acoustic modes; and optical modes in optical fiber. Two case studies were used to demonstrate this. Based on this numerical model, we report the influence of core radius, clad radius and effective refractive index on the Brillouin frequency shift and gain. We observe the difference of Brillouin shift frequency between a normal silica optical fiber and that of a microfiber - a uniformed silica fiber of a much smaller core and cladding dimensions where nonlinearities are higher. Also observed, the different core radii used and their respective Brillouin shift. For future work, the COMSOL model can also be used for the following areas of research, including simulating "surface Brillouin shift" and also to provide in-sights to the Brillouin shift frequency vB of various structures of waveguides, e.g circular, and triangular, and also to examine specialty fibers, e.g. Thulium and Chalcogenide doped fibers, and their effects on Brillouin shift frequency.
Fulltext Predictors of Persistence of Anxiety, Hyperarousal Stress, and Resilience During the COVID-19 Epidemic: A National Study in Iran

Sharif Nia H, Akhlaghi E, Torkian S, Khosravi V, Etesami R, Froelicher ES, et al.

Front Psychol, 2021;12:671124.
PMID: 34658994 DOI: 10.3389/fpsyg.2021.671124

Background: The coronavirus pandemic can cause unprecedented global anxiety, and, in contrast, resilience can help the mental health of people in stressful situations. This study aimed to assess anxiety, hyperarousal stress, the resilience of the Iranian population, and their related factors during the coronavirus disease 2019 (COVID-19) epidemic. Methods: A cross-sectional study was conducted in 31 provinces in Iran between March 18 and 25, 2020. A four-part questionnaire, including the demographic information, the State-Trait Anxiety Inventory (STAI-y1-a 20-item standard questionnaire for obvious anxiety), the Connor-Davidson Resilience Scale (CD-RISC-a 25 item standard questionnaire), and the stress hyperarousal subscale from the Impact of Event Scale-Revised (IES-R), was used to collect data. The ordinal multivariable generalized estimating equation (GEE) model was used to identify correlates of the psychological factors mentioned above. The Fisher exact test was used to investigate the relationship between anxiety, stress, resilience, and the COVID-19 outbreak. All analyses were conducted with SPSS 26 and GIS 10.71. Results: The findings show that most people had moderate-to-severe anxiety (80.17%) and a high level of resilience (96.4%) during the COVID-19 epidemic. The majority of participants had a moderate level of stress (58.9%). The lowest and highest prevalences of psychiatric disorders were in Sistan and Baluchestan (3.14 cases per 100,000 people) and Semnan (75.9 cases per 100,000 people) provinces, respectively. Men and unmarried people were the only variables significantly associated with anxiety and resilience. Age, gender, and education were significantly associated with hyperarousal stress. Conclusion: The high and moderate levels of anxiety and stress in Iranians can have negative effects on the well-being and performance of the people and can lead to serious problems. Also, high resilience during negative life events (such as the COVID-19 pandemic) is associated with the well-being in the lives of people. The results of this study can be used in interventions and other psychological studies.
Fulltext COVID-19 Disruptions in Health Professional Education: Use of Cognitive Load Theory on Students' Comprehension, Cognitive Load, Engagement, and Motivation

Hadie SNH, Tan VPS, Omar N, Nik Mohd Alwi NA, Lim HL, Ku Marsilla KI

Front Med (Lausanne), 2021;8:739238.
PMID: 34671622 DOI: 10.3389/fmed.2021.739238

This study explored the impact of online lectures that were developed using principles of cognitive load theory (CLT) and cognitive theory of multimedia learning (CTML) on health profession students' lecture comprehension, cognitive load, cognitive engagement, and intrinsic motivation in learning. A total of 215 first-year undergraduate students in medical, dentistry, and nutrition programs participated in this pre-post quasi experimental study. The students attended a typical face-to-face lecture on Day-1 of the intervention, followed by a CLT-based online lecture 8 weeks thereafter. Their comprehension of the lecture topics was measured through pre- and post-lecture assessments, and their cognitive load, cognitive engagement, and motivation were measured immediately after each lecture session. The analysis revealed that the CLT-based online lectures promoted the students' comprehension of the lecture content (p < 0.001), self-perceived learning (p < 0.001), engagement toward the learning material, and motivation to learn (p = 0.025). It was also effective at reducing the students' intrinsic and extraneous cognitive loads (p < 0.001). Hence, designing online lectures using CLT and CTML principles could be an effective method to promote students' knowledge and comprehension, cognitive engagement, and learning motivation. However, further research is needed to investigate the applicability and impact of CLT-based online lectures in non-health profession disciplines.
Fulltext Posttraumatic Growth and Coping Strategies Among Patients With Head and Neck Cancer: Do Approach Coping and Avoidant Coping Predict Posttraumatic Growth Over Time?

Nik Jaafar NR, Abd Hamid N, Hamdan NA, Rajandram RK, Mahadevan R, Mohamad Yunus MR, et al.

Front Psychol, 2021;12:716674.
PMID: 34764904 DOI: 10.3389/fpsyg.2021.716674

Despite an enormous number of studies addressing the importance of posttraumatic growth (PTG) among cancer patients, the literature lacks data regarding how different coping strategies affect PTG among head and neck cancer (HNC) patients over time. This longitudinal study investigated the PTG trend and coping over 5-7months among a cohort of HNC patients within the first year after their diagnosis. It determined an association between coping strategies and PTG over time. The study's HNC respondents were administered a socio-demographic and clinical characteristics questionnaire during their baseline assessments. Additionally, the Malay versions of the "PTG Inventory-Short Form" (PTGI-SF) and the "Brief Coping Orientation to Problems Experienced Inventory" (Brief COPE) were administered during respondents' baseline assessments and follow-up assessments (5-7months after the baseline assessments). In total, 200 respondents reported an increasing PTG trend and approach coping (active coping, planning, positive reframing, acceptance, emotional support, and instrumental support) and a decreasing trend of avoidant coping (self-distraction and denial) over time. Two approach coping strategies (acceptance and planning) significantly increased PTG while denial was the only avoidant coping strategy that significantly lowered PTG, after controlling for socio-demographic and clinical characteristics, over time. Our study's findings identified the need to incorporate psychosocial interventions that enhance approach coping and reduce avoidant coping into HNC patients' treatment regimes.
Fulltext Noise Eliminated Ensemble Empirical Mode Decomposition Scalogram Analysis for Rotating Machinery Fault Diagnosis

Faysal A, Ngui WK, Lim MH, Leong MS

Sensors (Basel), 2021 Dec 04;21(23).
PMID: 34884120 DOI: 10.3390/s21238114

Rotating machinery is one of the major components of industries that suffer from various faults due to the constant workload. Therefore, a fast and reliable fault diagnosis method is essential for machine condition monitoring. In this study, noise eliminated ensemble empirical mode decomposition (NEEEMD) was used for fault feature extraction. A convolution neural network (CNN) classifier was applied for classification because of its feature learning ability. A generalized CNN architecture was proposed to reduce the model training time. A sample size of 64×64×3 pixels RGB scalograms are used as the classifier input. However, CNN requires a large number of training data to achieve high accuracy and robustness. Deep convolution generative adversarial network (DCGAN) was applied for data augmentation during the training phase. To evaluate the effectiveness of the proposed feature extraction method, scalograms from related feature extraction methods such as ensemble empirical mode decomposition (EEMD), complementary EEMD (CEEMD), and continuous wavelet transform (CWT) are classified. The effectiveness of scalograms is also validated by comparing the classifier performance using grayscale samples from the raw vibration signals. All the outputs from bearing and blade fault classifiers showed that scalogram samples from the proposed NEEEMD method obtained the highest accuracy, sensitivity, and robustness using CNN. DCGAN was applied with the proposed NEEEMD scalograms to further increase the CNN classifier's performance and identify the optimal number of training data. After training the classifier using augmented samples, the results showed that the classifier obtained even higher validation and test accuracy with greater robustness. The proposed method can be used as a more generalized and robust method for rotating machinery fault diagnosis.

MeSH terms: Intelligence; Noise; Vibration; Neural Networks (Computer)*; Wavelet Analysis*
Fulltext Cytotoxicity of targeted PLGA nanoparticles: a systematic review

Chiu HI, Samad NA, Fang L, Lim V

RSC Adv, 2021 Mar 01;11(16):9433-9449.
PMID: 35423427 DOI: 10.1039/d1ra00074h

Recent advances in nanotechnology have contributed tremendously to the development and revolutionizing of drug delivery systems in the field of nanomedicine. In particular, targeting nanoparticles based on biodegradable poly(lactic-co-glycolic acid) (PLGA) polymers have gained much interest. However, PLGA nanoparticles remain of concern for their effectiveness against cancer cells and their toxicity to normal cells. The aim of this systematic review is to identify a promising targeting PLGA nanoformulation based on the comparison study of their cytotoxicity potency in different cell lines. A literature search was conducted through the databases of Google Scholar, PubMed, ScienceDirect, Scopus and SpringerLink. The sources studied were published between 2009 and 2019, and a variety of keywords were utilized. In total, 81 manuscripts that met the inclusion and exclusion criteria were selected for analysis based on their cytotoxicity, size, zeta potential, year of publication, type of ligand, active compounds and cell line used. The half maximal inhibitory concentration (IC50) for cytotoxicity was the main measurement in this data extraction, and the SI units were standardized to μg mL-1 for a better view of comparison. This systematic review also identified that cytotoxicity potency was inversely proportional to nanoparticle size. The PLGA nanoparticles predominantly exhibited a size of less than 300 nm and absolute zeta potential ∼20 mV. In conclusion, more comprehensive and critical appraisals of pharmacokinetic, pharmacokinetic, toxicokinetic, in vivo and in vitro tests are required for the investigation of the full value of targeting PLGA nanoparticles for cancer treatment.
Fulltext Including tree spatial extension in the evaluation of neighborhood competition effects in Bornean rain forest

Newbery DM, Stoll P

Ecol Evol, 2021 Jun;11(11):6195-6222.
PMID: 34141212 DOI: 10.1002/ece3.7452

Classical tree neighborhood models use size variables acting at point distances. In a new approach here, trees were spatially extended as a function of their crown sizes, represented impressionistically as points within crown areas. Extension was accompanied by plasticity in the form of crown removal or relocation under the overlap of taller trees. Root systems were supposedly extended in a similar manner. For the 38 most abundant species in the focal size class (10-<100 cm stem girth) in two 4-ha plots at Danum (Sabah), for periods P1 (1986-1996) and P2 (1996-2007), stem growth rate and tree survival were individually regressed against stem size, and neighborhood conspecific (CON) and heterospecific (HET) basal areas within incremented steps in radius. Model parameters were critically assessed, and statistical robustness in the modeling was set by randomization testing. Classical and extended models differed importantly in their outcomes. Crown extension weakened the relationship of CON effect on growth versus plot species' abundance, showing that models without plasticity overestimated negative density dependence. A significant negative trend of difference in CON effects on growth (P2-P1) versus CON or HET effect on survival in P1 was strongest with crown extension. Model outcomes did not then support an explanation of CON and HET effects being due to (asymmetric) competition for light alone. An alternative hypothesis is that changes in CON effects on small trees, largely incurred by a drought phase (relaxing light limitation) in P2, and following the more shaded (suppressing) conditions in P1, were likely due to species-specific (symmetric) root competition and mycorrhizal processes. The very high variation in neighborhood composition and abundances led to a strong "neighborhood stochasticity" and hence to largely idiosyncratic species' responses. A need to much better understand the roles of rooting structure and processes at the individual tree level was highlighted.
Fulltext Population-based Study Comparing Predictors of Ischemic Stroke Recurrence After Index Ischemic Stroke in Non-elderly Adults with or without Diabetes

Elhefnawy ME, Sheikh Ghadzi SM, Tangiisuran B, Zainal H, Looi I, Ibrahim KA, et al.

Int J Gen Med, 2021;14:1205-1212.
PMID: 33854362 DOI: 10.2147/IJGM.S303641

BACKGROUND AND PURPOSE: Factors associated with ischemic stroke (IS) recurrence and the contribution of pharmacological treatment as secondary preventions among nondiabetics especially in the non-elderly population are unclear and not widely investigated. This was a population-based study that aimed to identify recurrent IS predictors and to determine the possible impact of secondary preventive medications on the IS recurrence in non-elderly adults with or without diabetes.
METHODS: Data of 3386 patients <60 years old who had a history of index IS were extracted from the Malaysian National Neurology Registry (NNEUR) from 2009 to 2016. Recurrent IS was defined as any IS event recorded after the index IS in the NNEUR database. Multivariate logistic regression analysis was performed by using SPSS version 22.
RESULTS: Ischemic heart disease (IHD) was the significant predictor of IS recurrence in non-elderly adults both with or without diabetes (adjusted odds ratio (AOR) of 3.210; 95%CI: 1.909-5.398 and 2.989; 95%CI: 1.515-5.894) respectively). Receiving antiplatelet as secondary stroke prevention (AOR: 0.194; 95%CI: 0.046-0.817) and continuation of antidiabetic medication after the index IS event (AOR: 0.510; 95%CI: 0.298-0.872) reduced the odds of IS recurrence only in non-elderly diabetic adults. Among non-elderly adults without diabetes, hyperlipidemia and every increased in 1 mmHg of systolic blood pressure significantly increased the odds of IS recurrence following the indexing event (AOR: 1.796; 95%CI: 1.058-3.051 and 1.009; 95%CI: 1.002-1.016 respectively).
CONCLUSION: IHD was found as the main predictor of IS recurrence regardless of diabetes status in non-elderly adults after the index IS event. Receiving antidiabetic and antiplatelet medications upon discharge after index IS were significant predictors of recurrent IS in non-elderly diabetic adults. A proper randomized clinical trial may be required to determine the impact of secondary preventive medication on IS recurrence, especially in non-elderly adults.
Unsplinted Attachment Systems and Peri-implant Outcomes in Two-implant-retained Mandibular Overdentures: A Systematic Review of Randomized Controlled Trials

Patil PG, Seow LL, Kweh TJ, Nimbalkar S

J Contemp Dent Pract, 2021 Nov 01;22(11):1346-1354.
PMID: 35343463

AIM: The purpose of this review is to compare randomized clinical trials evaluating the peri-implant tissue outcomes using different unsplinted attachment systems in two implant-retained mandibular overdentures.
BACKGROUND: Literature lacks information on various unsplinted attachment systems and their effect on peri-implant tissue health. A focus question (as per PICOS) was set as follows: Does one particular unsplinted attachment system (I) compared with another (C) results in better peri-implant outcomes (O) in two implant-retained mandibular overdentures (P) using randomized controlled trials (RCTs) (S)? The literature search was conducted in the PubMed, MEDLINE and Cochrane Central Register of Controlled Trials (CENTRAL) databases between January 2011 and December 2021. The keywords used were "denture, overlay," "denture," "overlay" AND "dental prosthesis, implant supported," "dental implants," "dental implant abutment design" AND "jaw, edentulous," "mouth, edentulous" AND "mandible." Only RCTs on two implant-retained mandibular overdentures using unsplinted attachment systems measuring peri-implant tissue outcomes with minimum 1-year follow-up were selected. In total, 224 studies were identified in initial search, and 25 were shortlisted for full-text evaluation. Four studies were included for systematic review upon considering inclusion and exclusion criteria. The risk of bias was evaluated using Cochrane Risk of Bias Tool 2.0 (RoB 2.0).
REVIEW RESULTS: A total of 41 patients received ball attachments (in 3 studies), 36 patients received low-profile attachments (in 3 studies), 16 patients received magnet attachments (in 1 study), and 13 patients received telescopic attachments (in 1 study). All four studies used standard sized implants, however, differed in implant manufacturers. Two studies which compared ball attachments low-profile attachments revealed-similar peri-implant tissue health parameters but differed in crestal bone-level changes. One study compared ball with telescopic attachments and revealed similar results in crestal bone-level changes and all four peri-implant tissue health parameters. Single study compared magnets with low-profile attachments and shown lesser bone loss with magnet attachments. Single study was judged to have low risk of bias, single with some concerns, and remaining two to have high risk of bias.
CONCLUSION: Gingival index and bleeding index of the patients were not influenced by any of the unsplinted overdenture attachment (stud, magnet, telescopic) system. Inconclusive results found among the studies evaluated comparing crestal bone loss and plaque index.
CLINICAL SIGNIFICANCE: This review manuscript has simplified comparative analysis of different unsplinted attachment systems used in two implant mandibular overdentures to help clinicians choose correct system in such situation.

MeSH terms: Denture Retention/methods; Denture, Overlay*; Humans; Jaw, Edentulous*; Mandible; Randomized Controlled Trials as Topic; Dental Prosthesis, Implant-Supported
Fulltext Editorial: Malnutrition: A Cause or a Consequence of Poverty?

Ma ZF, Wang CW, Lee YY

Front Public Health, 2021;9:796435.
PMID: 35059381 DOI: 10.3389/fpubh.2021.796435
Fulltext The Role of Service Recovery in Post-purchase Consumer Behavior During COVID-19: A Malaysian Perspective

Mazhar M, Ting DH, Hussain A, Nadeem MA, Ali MA, Tariq U

Front Psychol, 2021;12:786603.
PMID: 35185687 DOI: 10.3389/fpsyg.2021.786603

The purpose of this study is to investigate the incidence of service failure in rendering service process during COVID-19. It further explores the outcomes of service recovery offered to customers in case of service failure. Like other businesses, webstores have also faced the challenges in their efforts to satisfy their customers during COVID-19. Service failure has increased due to unexpected circumstances produced by this pandemic. It has become necessary for the webstores to retain their dissatisfied customers by reconsidering their service strategies. Relevant data for the purpose of this study were collected through questionnaires from 383 respondents by using online channels. The online channels were exclusively employed for maintaining the safety of respondents during COVID-19. Respondents for this study were online shoppers who encountered service failure during COVID-19. The results indicated that the incidence of service failure has increased due to an increase in online shopping during COVID-19. Some customers tend to repurchase from the same webstore. On the other hand, some customers do not want to purchase again from the same seller and decided to switch to the alternative webstore. Based on the findings, new strategy for online shopping service providers was introduced. This strategy will be helpful for the online service providers to increase their profitability by retaining their dissatisfied customers. Service providers can minimize the number of customers switching to other webstores by reducing the events of service failure. Customer's assistive intent can also be helpful for service providers to increase the efficiency of service recovery. Conducting a proper follow-up after providing service recovery can also reduce the switching of customer. It will be helpful for service providers to understand the customers' expectations before recovery process and their feeling after getting service recovery.
Fulltext Survival Analysis of COPD Patients in a 13-Year Nationwide Cohort Study of the Brazilian National Health System

Gargano LP, Zuppo IF, do Nascimento MMG, Augusto VM, Godman B, Costa JO, et al.

Front Big Data, 2021;4:788268.
PMID: 35198972 DOI: 10.3389/fdata.2021.788268

BACKGROUND: Chronic obstructive pulmonary disease (COPD) has an appreciable socioeconomical impact in low- and middle-income countries, but most epidemiological data originate from high-income countries. For this reason, it is especially important to understand survival and factors associated with survival in COPD patients in these countries.
OBJECTIVE: To assess survival of COPD patients in Brazil, to identify risk factors associated with overall survival, including treatment options funded by the Brazilian National Health System (SUS).
METHODOLOGY: We built a retrospective cohort study of patients dispensed COPD treatment in SUS, from 2003 to 2015 using a National Database created from the record linkage of administrative databases. We further matched patients 1:1 based on sex, age and year of entry to assess the effect of the medicines on patient survival. We used the Kaplan-Meier method to estimate overall survival of patients, and Cox's model of proportional risks to assess risk factors.
RESULT: Thirty seven thousand and nine hundred and thirty eight patients were included. Patient's survival rates at 1 and 10 years were 97.6% (CI 95% 97.4-97.8) and 83.1% (CI 95% 81.9-84.3), respectively. The multivariate analysis showed that male patients, over 65 years old and underweight had an increased risk of death. Therapeutic regimens containing a bronchodilator in a free dose along with a fixed-dose combination of corticosteroid and bronchodilator seem to be a protective factor when compared to other regimens.
CONCLUSION: Our findings contribute to the knowledge of COPD patients' profile, survival rate and related risk factors, providing new evidence that supports the debate about pharmacological therapy and healthcare of these patients.
Fulltext Factors Associated With Underprivileged E-Learning, Session Jam Phobia, and the Subsequent Mental Distress Among Students Following the Extended University Closure in Bangladesh

Hossain MJ, Ahmmed F, Sarker MMR, Sarwar S, Bari MS, Khan MR, et al.

Front Public Health, 2021;9:807474.
PMID: 35223762 DOI: 10.3389/fpubh.2021.807474

Severe session jam phobia (SJP), the extent of underprivileged online education, and subsequent mental health disorders among students have emerged as distinguished global problems due to the overwhelming effects of coronavirus disease 2019 (COVID-19). The purpose of this research was to evaluate the impact of extended COVID-19 lockdown and its mediating factors on current e-Learning activities, the prevalence of severe SJP and psychological distress among university students in Bangladesh. A web-based cross-sectional study was conducted to assemble responses through Google Form by applying a simple snowball sampling technique among university students aged 18 years or above in Bangladesh. All ethical considerations were maintained, and univariate, bivariate, and multivariate analyses were employed to analyze the acquired data set. Among the total analyzed data (n = 1,122), the male and female ratio was almost 1:1, and a remarkable segment (63.7%) was aged between 21-24 years. Alarmingly, around 50-60% of the students were suffering from severe SJP, prevailing underprivileged education in the e-Learning platform, and severe mental distress. Logistic regression analyses demonstrated that the students from public universities, lower- and mid-income families, lower-aged, and junior years education groups were significantly (p < 0.05) more underprivileged than their counter groups. Besides, the monthly family income and university type significantly influenced the extent of severe SJP. Finally, the students who were female, rustic, come from low-income families (below 25,000 BDT), who had academic uncertainty, job insecurity, online exam phobia, and dissatisfaction with e-Learning education, were significantly suffering from moderate to severe mental distress. The current evidence demonstrates that a substantial number of Bangladeshi university students are struggling with extreme session jam phobia, underprivileged e-Learning education, and subsequent psychological distress, which need to be immediately addressed through concerted efforts by the government, parents, and university authorities.

MeSH terms: Adult; Bangladesh/epidemiology; Communicable Disease Control; Computer-Assisted Instruction*; Cross-Sectional Studies; Female; Humans; Male; Students/psychology; Universities; Young Adult
Fulltext Strategies for the preparation of non-amplified and amplified genomic dengue gene samples for electrochemical DNA biosensing applications

Abdul Rashid JI, Yusof NA, Abdullah J, Shomiad Shueb RH

RSC Adv, 2021 Dec 20;12(1):1-10.
PMID: 35424522 DOI: 10.1039/d1ra06753b

The application of electrochemical DNA biosensors in real genomic sample detection is challenging due to the existence of complex structures and low genomic concentrations, resulting in inconsistent and low current signals. This work highlights strategies for the treatment of non-amplified and amplified genomic dengue virus gene samples based on real samples before they can be used directly in our DNA electrochemical sensing system, using methylene blue (MB) as a redox indicator. The main steps in this study for preparing non-amplified cDNA were cDNA conversion, heat denaturation, and sonication. To prepare amplified cDNA dengue virus genomic samples using an RT-PCR approach, we optimized a few parameters, such as the annealing temperature, sonication time, and reverse to forward (R/F) primer concentration ratio. We discovered that the generated methylene blue (MB) signals during the electrochemical sensing of non-amplified and amplified samples differ due to the different MB binding affinities based on the sequence length and base composition. The findings show that our developed electrochemical DNA biosensor successfully discriminates MB current signals in the presence and absence of the target genomic dengue virus, indicating that both samples were successfully treated. This work also provides interesting information about the critical factors in the preparation of genomic gene samples for developing miniaturized PCR-based electrochemical sensing applications in the future. We also discuss the limitations and provide suggestions related to using redox-indicator-based electrochemical biosensors to detect real genomic nucleic acid genes.
Fulltext In-hospital mortality in SARS-CoV-2 stratified by hemoglobin levels: A retrospective study

Al-Jarallah M, Rajan R, Saber AA, Pan J, Al-Sultan AT, Abdelnaby H, et al.

EJHaem, 2021 Aug;2(3):335-339.
PMID: 34226901 DOI: 10.1002/jha2.195

This study is to estimate in-hospital mortality in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) patients stratified by hemoglobin (Hb) level. Patients were stratified according to hemoglobin level into two groups, that is, Hb <100 g/L and Hb >100 g/L. A total of 6931 patients were included. Of these, 6377 (92%) patients had hemoglobin levels >100 g/L. The mean age was 44 ± 17 years, and 66% of the patients were males. The median length of overall hospital stay was 13 days [2; 31]. The remaining 554 (8%) patients had a hemoglobin level <100 g/L. Overall mortality was 176 patients (2.54%) but was significantly higher in the group with hemoglobin levels <100 g/L (124, 22.4%) than in the group with hemoglobin levels >100 g/L (52, 0.82%). Risk factors associated with increased mortality were determined by multivariate analysis. The Kaplan-Meier survival analysis showed hemoglobin as a predictor of mortality. Cox proportional hazards regression coefficients for hemoglobin for the HB ≤ 100 category of hemoglobin were significant, B = 2.79, SE = 0.17, and HR = 16.34, p
Fulltext Optimisation of a gold nanoparticle-based aptasensor integrated with image processing for the colorimetric detection of acephate using response surface methodology

Osman MJ, Abdul Rashid JI, Khim OK, Zin Wan Yunus WM, Mohd Noor SA, Mohd Kasim NA, et al.

RSC Adv, 2021 Jul 27;11(42):25933-25942.
PMID: 35479481 DOI: 10.1039/d1ra04318h

Acephate (Ac) is an organophosphate (OP) compound, which is able to inhibit the activity of acetylcholinesterase. Thus, the aim of this study was to optimize the detection of Ac using a thiolated acephate binding aptamer-citrate capped gold nanoparticle (TABA-Cit-AuNP) sensor that also incorporated an image processing technique. The effects of independent variables, such as the incubation period of TABA-Cit-AuNPs (3-24 h) for binding TABA to Cit-AuNPs, the concentration of phosphate buffer saline (PBS) (0.001-0.01 M), the concentration of thiolated acephate binding aptamer (TABA) (50-200 nM), and the concentration of magnesium sulphate (MgSO4) (1-300 mM) were investigated. A quadratic model was developed using a central composite design (CCD) from response surface methodology (RSM) to predict the sensing response to Ac. The optimum conditions such as the concentration of PBS (0.01 M), the concentration of TABA (200 nM), the incubation period of TABA-Cit-AuNPs (3 h), and the concentration of MgSO4 (1 mM) were used to produce a TABA-Cit-AuNPs sensor for the detection of Ac. Under optimal conditions, this sensor showed a detection ranging from 0.01 to 2.73 μM and a limit of detection (LOD) of 0.06 μM. Real sample analysis demonstrated this aptasensor as a good analytical method to detect Ac.
Fulltext Gold nanoparticles conjugated with anti-CD133 monoclonal antibody and 5-fluorouracil chemotherapeutic agent as nanocarriers for cancer cell targeting

Mohd-Zahid MH, Zulkifli SN, Che Abdullah CA, Lim J, Fakurazi S, Wong KK, et al.

RSC Adv, 2021 Apr 26;11(26):16131-16141.
PMID: 35481195 DOI: 10.1039/d1ra01093j

The enhanced permeability and retention effect allows for passive targeting of solid tumours by nanoparticles carrying anticancer drugs. However, active targeting by incorporation of various ligands onto nanoparticles can provide for a more selective and enhanced chemotherapeutic effect and complement the deficiencies of the passive targeting approach. Here we report on the design of the carboxyl-terminated PEGylated gold nanoparticles (AuNPs), their functionalization with anti-CD133 monoclonal antibody (mAb) via a crosslinking reaction, and subsequent 5-fluorouracil (5-FU) drug loading. The synthesized products in the form of stable colloids were characterised using a range of physicochemical techniques, including X-ray diffraction (XRD), UV-Vis spectroscopy, transmission electron microscopy (TEM), and dynamic light scattering (DLS). Conjugation of anti-CD133 mAb onto PEGylated AuNPs was confirmed with the use of UV-Vis, BCA protein assay and fluorescence microscopy. HCT116 colorectal cancer cells abundantly expressed CD133: 92.4 ± 1.3%, as measured by flow cytometry. Whereas PEGylated AuNPs not conjugated with anti-CD133 mAb accumulated mainly at the cellular membrane, nanoparticles conjugated with anti-CD133 mAb were contained within the nuclear region of the cells. Anti-CD133 mAb conjugation facilitated the specific intracellular uptake due to specific antigen-antibody binding interaction. In vitro cytotoxicity studies on HCT116 cells showed that PEGylated AuNPs and PEGylated AuNPs-CD133 did not elicit any toxicity at any of the tested concentrations. Meanwhile, 5-FU-PEGylated AuNPs-CD133 significantly reduced the cell viability relative to the treatment with 5-FU-PEGylated AuNPs without anti-CD133 mAb conjugates (p < 0.0001). This study shows that the conjugation of nanocarriers with the anti-CD133 antibody improves the specific targeting of 5-FU against colorectal cancer cells. These results demonstrate that simultaneous functionalisation of PEGylated AuNPs with antibodies and chemotherapeutic drugs is a viable strategy to combat cancer through targeted drug delivery.
Fulltext Lipid oxidation and protein co-oxidation in ready-to-eat meat products as affected by temperature, antioxidant, and packaging material during 6 months of storage

Wazir H, Chay SY, Ibadullah WZW, Zarei M, Mustapha NA, Saari N

RSC Adv, 2021 Nov 29;11(61):38565-38577.
PMID: 35493245 DOI: 10.1039/d1ra06872e

Ambient-storage-friendly, ready-to-eat (RTE) meat products are convenient in emergencies, such as earthquakes, flash floods and the current global Covid-19 lockdown. However, given the processing and long storage time of such food products, the lipid and protein components may be more susceptible to oxidation. Chicken serunding is a low-moisture, high-lipid, high-protein, RTE product that is prone to lipid oxidation and protein co-oxidation, causing product quality deterioration. The present study assessed the effects of storage temperature (25, 40, 60 °C), antioxidant (butylated hydroxyanisole, BHA), and multilayer packaging materials [metallised polyethene terephthalate (MPET) and aluminium] on the lipid oxidation and protein co-oxidation of chicken serunding during six months of storage. All lipid and protein markers elevated with increasing temperature (25 < 40 < 60 °C), indicating that storage of low-moisture meat at high temperature is not feasible. BHA was effective against lipid oxidation, as indicated by the significantly lower (p <0.05) extracted lipid content and delayed formation of malondialdehyde, a secondary lipid oxidation product. However, BHA is not effective against protein co-oxidation, as shown by the insignificant (p >0.05) effect on preventing tryptophan loss, protein carbonyl formation and Schiff base accumulation. MPET packaging with a superior light and oxygen barrier provided significant protection (p <0.05) compared to aluminium. In conclusion, low temperature (25 °C) storage of low-moisture, high-lipid, high-protein, cooked meat systems in MPET packaging is recommended for long-term storage to delay the progression of lipid oxidation and protein co-oxidation.
Non-Pharmacological Infection Prevention and Control Interventions in COVID-19: What Does the Current Evidence Say?

Shankar PR, Palaian S, Vannal V, Sreeramareddy CT

Int J Prev Med, 2021;12:174.
PMID: 37663401 DOI: 10.4103/ijpvm.IJPVM_604_20

Coronavirus disease-19 (COVID-19), a major global public health emergency has significantly impacted human health and livelihoods. The pandemic continues to spread and treatments and vaccines are at different stages of development. Mass vaccination has been rolled out worldwide. This review article provides a narrative summary of the evidence on various non-pharmacological interventions (NPIs) for COVID-19 containment. The authors reviewed the evidence published by the Norwegian Institute of Public Health map of COVID-19 evidence. Additional literature was identified from PubMed and Google Scholar, preprint sites, and news media. The search terms included "Social distancing measures" and "COVID 19", "Non-pharmacological interventions'' and "COVID 19", "COVID-19", "non-pharmacological interventions", "face mask", etc. The strength of the evidence for most studies on NPIs was 'weak to moderate' for restrictive NPIs. Ascertaining the impact of each NPI as a standalone intervention is difficult since NPIs are implemented simultaneously with other measures. Varying testing and reporting strategies across the countries and classification of deaths directly caused by COVID-19 create challenges in assessing the impact of restrictive NPIs on the case numbers and deaths. Evidence on hygiene measures such as face mask is more robust in design providing credible evidence on prevention of COVID-19 infection. Evidence from modeling studies, natural before-after studies, and anecdotal evidence from the strategies adopted by 'role model' countries suggests that continued use of NPIs is the only containment strategy until 'herd immunity' is achieved to reduce the severe disease and mortality.
Refractive amblyopia among children aged 4-12 years in a hospital-based setting in Gaza Strip, Palestine

Eslayeh AH, Omar R, Fadzil NM

Med Hypothesis Discov Innov Ophthalmol, 2021;10(3):107-113.
PMID: 37641712 DOI: 10.51329/mehdiophthal1428

BACKGROUND: Refractive amblyopia is the most common cause of amblyopia in the Gaza Strip. However, the pattern of this condition has not yet been studied in this region. This study aimed to determine the pattern of refractive amblyopia in Gazan children aged 4‒12 years.
METHODS: This was a hospital-based cross-sectional study using a purposive sampling method. Children aged 4‒12 years who attended the Children's Unit at Gaza Ophthalmic Hospital, Gaza Strip, Palestine from September 2019 to July 2020, were examined. A comprehensive eye test was conducted for all participants. Those who failed the eye examinations and were diagnosed with refractive amblyopia were included in the study. Demographic data and amblyopic refractive error patterns were analyzed accordingly.
RESULTS: Of the 107 children, 72.9% were newly diagnosed with refractive amblyopia. The mean (standard deviation [SD]) of age of the children who participated was 7.85 (1.55) years. Approimately two-thirds of the patients were female (57.9%). Unilateral amblyopia was predominant in 60.7% of the cases. Moderate amblyopia was common (81.9%). A total of 149 amblyopic eyes were examined in total, with a mean (SD) (range) of best-corrected distance visual acuity and spherical equivalent of 0.45 (0.19) (0.2 to 1.3) logarithm of the minimum angle of resolution and + 0.76 (4.51) diopters (- 10.25 to + 11.50). Astigmatism was the most common amblyogenic factor (53.7%) among children with amblyopia.
CONCLUSIONS: The frequency of refractive amblyopia was 72.9%, and meridional amblyopia accounted for the highest percentage. Girls were more commonly affected than boys. The majority were in the 7-year-old age group. Most cases were unilateral with moderate refractive amblyopia. Our study yields insights into the patterns of refractive amblyopia among children in the Gaza Strip.

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