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Application of Bpw34 photodiode and cold white LED as diagnostic X-ray detectors: A comparative analysis

Damulira E, Yusoff MNS, Omar AF, Mohd Taib NH, Ahmed NM

Appl Radiat Isot, 2021 Apr;170:109622.
PMID: 33592486 DOI: 10.1016/j.apradiso.2021.109622

This study compares the real-time dosimetric performance of a bpw34 photodiode (PD) and cold white light-emitting diodes (LEDs) based on diagnostic X-ray-induced signals. Signals were extracted when both the transducers were under identical exposure settings, including source-to-detector distance (SDD), tube voltage (kVp), and current-time product (mAs). The transducers were in a photovoltaic configuration, and black vinyl tape was applied on transducer active areas as a form of optical shielding. X-ray beam spectra and energies were simulated using Matlab-based Spektr functions. Transducer performance analysis was based on signal linearity to mAs and air kerma, and sensitivity dependence on absorbed dose, energy, and dose rate. Bpw34 PD and cold white LED output signals were 84.8% and 85.5% precise, respectively. PD signals were 94.7% linear to mAs, whereas LED signals were 91.9%. PD and LED signal linearity to dose coefficients were 0.9397 and 0.9128, respectively. Both transducers exhibited similar dose and energy dependence. However, cold white LEDs were 0.73% less dose rate dependent than the bpw34 PD. Cold white LEDs demonstrated potential in detecting diagnostic X-rays because their performance was similar to that of the bpw34 PD. Moreover, the cold white LED array's dosimetric response was independent of the heel effect. Although cold white LED signals were lower than bpw34 PD signals, they were quantifiable and electronically amplifiable.
Fulltext Efficacy of the Aqueous Extract of Azadirachta indica Against the Marine Parasitic Leech and Its Phytochemical Profiling

Venmathi Maran BA, Josmeh D, Tan JK, Yong YS, Shah MD

Molecules, 2021 Mar 29;26(7).
PMID: 33805254 DOI: 10.3390/molecules26071908

Zeylanicobdella arugamensis (Hirudinea), a marine parasitic leech, not only resulted in the mortality of the host fish (Groupers) but also caused economic losses. The current study aimed to elucidate the antiparasitic efficacy of the aqueous extract of the Azadirachta indica leaves against Z. arugamensis and to profile the composition via LC-Q Exactive HF Orbitrap mass spectrometry. Different concentrations (25, 50 and 100 mg/mL) of A. indica extract were prepared and tested on the parasitic leeches. The total mortality of leeches was noticed with an exposure to the A. indica aqueous extract. The average times required for the aqueous extract at concentrations of 25, 50 and 100 mg/mL to kill the leeches were 42.65 ± 9.20, 11.69 ± 1.11 and 6.45 ± 0.45 min, respectively, in a dose-dependent manner. The Orbitrap mass spectrometry analysis indicated the presence of five flavonoids (myricetin 3-O-galactoside, trifolin, isorhamnetin, quercetin and kaempferol), four aromatics (4-methoxy benzaldehyde, scopoletin, indole-3-acrylic acid and 2,4-quinolinediol), three phenolics (p-coumaric acid, ferulic acid and phloretin) and two terpenoids (pulegone and caryophyllene oxide). Thus, our study indicates that A. indica aqueous extract is a good source of metabolites with the potential to act as a biocontrol agent against the marine parasitic leech in aquaculture.
Polymerase chain reaction cycle threshold value as prerequisite for reporting of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) detection

Awang H, Hamzah FH, Ahmad MH, Mahmood MF, Wahab A, Embong K, et al.

Infect Dis (Lond), 2021 05;53(5):390-392.
PMID: 33512265 DOI: 10.1080/23744235.2021.1876913
Fulltext Knowledge, attitude and perceptions about Crimean Congo Haemorrhagic Fever (CCHF) among occupationally high-risk healthcare professionals of Pakistan

Ahmed A, Saqlain M, Tanveer M, Tahir AH, Ud-Din F, Shinwari MI, et al.

BMC Infect Dis, 2021 Jan 07;21(1):35.
PMID: 33413164 DOI: 10.1186/s12879-020-05714-z

BACKGROUND: Crimean Congo Haemorrhagic Fever (CCHF), a tropically neglected infectious disease caused by Nairovirus, is endemic in low middle-income countries like Pakistan. Emergency health care professionals (HCPs) are at risk of contracting nosocomial transmission of CCHF. We, therefore, aim to analyze the knowledge, attitudes, and perceptions (KAP) of at-risk physicians, nurses, and pharmacists in Pakistan and the factors associated with good KAP.
METHOD: A validated questionnaire (Cronbach's alpha 0.71) was used to collect data from HCPs in two CCHF endemic metropolitan cities of Pakistan by employing a cross-sectional study design. For data analysis percentages, chi-square test and Spearman correlation were applied by using SPSS version 22.
RESULTS: Of the 478 participants, 56% (n = 268) were physicians, 37.4% (n = 179) were nurses, and 6.5% (n = 31) were pharmacists. The proportion of HCPs with good knowledge, attitude, and perception scores was 54.3%, 81, and 69%, respectively. Being a physician, having more work experience, having a higher age, working in tertiary care settings, were key factors for higher knowledge (p
Fulltext RF-Based Moisture Content Determination in Rice Using Machine Learning Techniques

Azmi N, Kamarudin LM, Zakaria A, Ndzi DL, Rahiman MHF, Zakaria SMMS, et al.

Sensors (Basel), 2021 Mar 08;21(5).
PMID: 33800174 DOI: 10.3390/s21051875

Seasonal crops require reliable storage conditions to protect the yield once harvested. For long term storage, controlling the moisture content level in grains is challenging because existing moisture measuring techniques are time-consuming and laborious as measurements are carried out manually. The measurements are carried out using a sample and moisture may be unevenly distributed inside the silo/bin. Numerous studies have been conducted to measure the moisture content in grains utilising dielectric properties. To the best of authors' knowledge, the utilisation of low-cost wireless technology operating in the 2.4 GHz and 915 MHz ISM bands such as Wireless Sensor Network (WSN) and Radio Frequency Identification (RFID) have not been widely investigated. This study focuses on the characterisation of 2.4 GHz Radio Frequency (RF) transceivers using ZigBee Standard and 868 to 915 MHz UHF RFID transceiver for moisture content classification and prediction using Artificial Neural Network (ANN) models. The Received Signal Strength Indicator (RSSI) from the wireless transceivers is used for moisture content prediction in rice. Four samples (2 kg of rice each) were conditioned to 10%, 15%, 20%, and 25% moisture contents. The RSSI from both systems were obtained and processed. The processed data is used as input to different ANNs models such as Support Vector Machine (SVM), K-Nearest Neighbour (KNN), Random Forest, and Multi-layer Perceptron (MLP). The results show that the Random Forest method with one input feature (RSSI_WSN) provides the highest accuracy of 87% compared to the other four models. All models show more than 98% accuracy when two input features (RSSI_WSN and RSSI_TAG2) are used. Hence, Random Forest is a reliable model that can be used to predict the moisture content level in rice as it gives a high accuracy even when only one input feature is used.
Fulltext Acute Retropharyngeal Calcific Tendonitis as a Rare Cause of Odynophagia and Neck Pain

Singh PKM, Noor MIM, Jaafar R, Ahmad A, Mohamad I

Medeni Med J, 2021;36(1):75-79.
PMID: 33828894 DOI: 10.5222/MMJ.2021.37539

Retropharyngeal calcific tendonitis (RCT) is an aseptic inflammatory process of the superior oblique tendons of the longus colli muscle caused by the deposition of calcium hydroxyapatite crystals. We reported a 23-year-old woman who presented with a sudden onset of neck pain with odynophagia after waking up from sleep. Physical examination showed paracervical point tenderness with limited neck movement in all directions. Prior to surgery, further imaging was requested to aid in diagnosis, which in turn revealed RCT. It is important to be aware that RCT presentation may mimic other severe conditions such as retropharyngeal space abscess or meningitis.
Fulltext The Development and Assessment of Modified Fagerstrom Test for Nicotine Dependence Scale among Malaysian Single Electronic Cigarette Users

Rahman AU, Mohamed MHN, Jamshed S, Mahmood S, Iftikhar Baig MA

J Pharm Bioallied Sci, 2020 Nov;12(Suppl 2):S671-S675.
PMID: 33828359 DOI: 10.4103/jpbs.JPBS_245_19

Background: The Fagerstrom test for nicotine dependence (FTND) is the most widely used scale for assessing nicotine dependence on conventional tobacco cigarettes (TCGs). But the FTND does not evaluate the subject's nicotine dependence to electronic cigarette (EC).
Objective: The aim of this study was to develop and assess an equivalent modified FTND scale that measures the nicotine dependency via EC.
Materials and Methods: The investigator developed the equivalent modified FTND scale that scores identical to the original scale, that is, 0-10. The developed scale piloted among 15 EC single users, that is, use only EC verified by carbon monoxide (CO) level of <8ppm. The assessment of the scale was done among 69 EC single users and observed for 1 year to determine their nicotine status.
Results: The modified scale revealed an acceptable Cronbach α value of 0.725. Further test-retest reliability of the scale showed a satisfactory Spearman's rank correlation coefficient value of 0.730 (P > 0.05). A 1-year observation showed that of 69 single users, 11 single users completely stopped nicotine intake, 24 remained as EC single users, 15 shifted to dual-use, and 19 relapsed to TCG. Surprisingly, the EC users who completely stopped nicotine intake after 1 year had a low average nicotine dependence value of 3 that was measured by the modified FTND scale at the baseline.
Conclusion: The modified FTND scale precisely identifies the physical dependence to nicotine via EC. Therefore, as per this study results the modified FTND scale can be applied in any EC-related studies to assess nicotine dependency via EC.
Fulltext Highly Sensitive Magnesium-Doped ZnO Nanorod pH Sensors Based on Electrolyte-Insulator-Semiconductor (EIS) Sensors

Al-Khalqi EM, Abdul Hamid MA, Al-Hardan NH, Keng LK

Sensors (Basel), 2021 Mar 17;21(6).
PMID: 33802968 DOI: 10.3390/s21062110

For highly sensitive pH sensing, an electrolyte insulator semiconductor (EIS) device, based on ZnO nanorod-sensing membrane layers doped with magnesium, was proposed. ZnO nanorod samples prepared via a hydrothermal process with different Mg molar ratios (0-5%) were characterized to explore the impact of magnesium content on the structural and optical characteristics and sensing performance by X-ray diffraction analysis (XRD), atomic force microscopy (AFM), and photoluminescence (PL). The results indicated that the ZnO nanorods doped with 3% Mg had a high hydrogen ion sensitivity (83.77 mV/pH), linearity (96.06%), hysteresis (3 mV), and drift (0.218 mV/h) due to the improved crystalline quality and the surface hydroxyl group role of ZnO. In addition, the detection characteristics varied with the doping concentration and were suitable for developing biomedical detection applications with different detection elements.
Fulltext The Prevalence of Prescribing Medications Associated with Geriatric Syndromes among Discharged Elderly Patients

Akkawi ME, Mohd Taufek NH, Abdul Hadi AD, Nik Lah NNNF

J Pharm Bioallied Sci, 2020 Nov;12(Suppl 2):S747-S751.
PMID: 33828372 DOI: 10.4103/jpbs.JPBS_305_19

Introduction: A geriatric syndrome is a group of signs and symptoms that occur in older people and do not fit into a discrete disease. Several medications were reported to be associated with the incidence of geriatric syndromes.
Objective: The objective of this study was to investigate the prevalence and pattern of medications associated with geriatric syndromes (MAGSs) among the discharged elderly patients (≥65 years old).
Materials and Methods: This is a cross-sectional study that was conducted at a Malaysian teaching hospital from October to December 2018. The discharge medications of geriatric patients were reviewed to identify MAGSs using Beers criteria, Lexicomp drug information handbook, and the United States Food and Drug Administration (USFDA) drug inserts. Chi-square test was used to compare MAGS prescribed between categories. Spearman's rank-order correlation was used to test the correlation between the presence of MAGS and the number of discharge medications. A binomial logistic regression was applied to determine the predictors of prescribing MAGSs.
Results: A total of 400 patients (mean ± standard deviation [SD] age, 72.0 ± 5.0 years) were included, and 45.3% of them were females. The most common diseases were hypertension followed by diabetes mellitus. The mean ± SD number of discharge medications per patient was 4.2 ± 2.5. The MAGSs were prescribed in 51.7% of the patients, and 54 patients were discharged with more than one MAGSs. The most commonly prescribed MAGSs were opioid analgesics, vasodilators, and β-blockers, which are associated with falls, depression, and delirium. Polypharmacy was found in 138 patients, and it was significantly associated with the presence of MAGSs (P < 0.001). No significant differences were found in prescribing MAGSs based on the patients' gender, race, and age.
Conclusion: The prescribing of MAGSs occurred in half of the discharged elderly patients. Physicians should be aware of the medications that are associated with special side effects in the elderly patients, and should switch to safer alternatives when possible.
Infectious bronchitis associated with Escherichia coli infection in commercial broiler chickens: a case report

Nordin N, Sani NIM, Kadir AA, Shaari R, Mohamed M, Reduan MFH, et al.

J Adv Vet Anim Res, 2021 Mar;8(1):101-104.
PMID: 33860019 DOI: 10.5455/javar.2021.h491

Objective: In this case report, we have investigated the infectious bronchitis (IB) virus (IBV) outbreak with the co-infection of Escherichia coli in 28-33-day-old broiler chickens in Malaysia.
Materials and Methods: A farmer complained that Cobb 500 chickens, raised in the open house, were having bloody diarrhea, open mouth breathing, non-uniform growth, and ruffled feathers. The mortality was about 100 birds (from about 7000 birds) per day. The sick birds were isolated and subjected to physical examination, postmortem, and histopathological analyses. Gross lesions were observed and recorded. The lung samples have proceeded with histopathological evaluations. The lungs, kidneys, trachea, air sac, and heart samples were collected to isolate bacteria and fungi through a series of conventional cultural methods, followed by molecular confirmation of the IBV.
Results: Postmortem examination revealed air sacculitis, hemorrhagic tracheitis, pulmonary congestion, fibrin deposition in the liver and air sac, hemorrhagic enteritis, and renomegaly. The bacterial culture and biochemical tests revealed E. coli in the lungs, trachea, liver, intestine, and kidney samples. However, no fungus could be isolated from those samples. Histological evaluation of lung samples demonstrated infiltration of inflammatory cells in the pulmonary tissues. Apart from this, reverse transcription-polymerase chain reaction confirmed the presence of avian coronavirus responsible for infectious bronchitis (IB).
Conclusion: The chickens were diagnosed with IB concurrent with E.coli. The chickens exhibited typical nephropathogenic strain of IBV infection, causing high mortality.
Fulltext Inverse changes in plasma tetranectin and titin levels in patients with type 2 diabetes mellitus: a potential predictor of acute myocardial infarction?

Rahim MAA, Rahim ZHA, Ahmad WAW, Bakri MM, Ismail MD, Hashim OH

Acta Pharmacol Sin, 2018 Jul;39(7):1197-1207.
PMID: 29417940 DOI: 10.1038/aps.2017.141

An early intervention using biomarkers to predict acute myocardial infarction (AMI) will effectively reduce global heart attack incidence, particularly among high-risk patients with type 2 diabetes mellitus (T2DM). This study attempted to identify potential biomarkers by detecting changes in the levels of plasma proteins in T2DM patients following onset of AMI in comparison with those without AMI. Volunteer T2DM patients without AMI (control; n=10) and T2DM patients with AMI (n=10) were recruited. Plasma samples from these patients were evaluated via two-dimensional gel electrophoresis (2DE) to screen for proteins with level changes between the two groups. The abundance of spots on gel images was analyzed using Progenesis SameSpots and subjected to false discovery rate (FDR) analysis. Protein spots with statistically significant changes of at least 1.5 fold were selected for mass spectrometry (MS) analysis. Due to strong cardiac connections, tetranectin and titin were evaluated by enzymelinked immunosorbent assay (ELISA). The adjusted P-values and fold changes between the two groups resulted in identification of 34 protein spots with significantly altered abundance. Upon MS analysis, 17 plasma proteins were identified: tetranectin, titin, clusterin, haptoglobin, myosin-13, zinc fnger protein 445, DNA repair protein RAD50, serum albumin, apolipoprotein A-IV, caspase-6, aminoacyl tRNA synthase complex-interacting multifunctional protein 1, serotransferrin, retinol-binding protein 4, transthyretin, alpha-1-antitrypsin, apolipoprotein A-I and serum amyloid A. Comparable patterns of changes in tetranectin and titin between the control and AMI groups were confirmed using ELISA. In summary, tetranectin and titin in plasma appeared to be closely associated with the onset of AMI among T2DM patients and can be used as potential biomarkers for prediction of a cardiac event, though this requires validation in a prospective cohort study.
Fulltext Sequence and phylogeny of the complete mitochondrial genome of the Himalayan jungle crow (Corvidae: Corvus macrorhynchos intermedius) from Pakistan

Iqbal F, Ayub Q, Song BK, Wilson R, Fahim M, Rahman S

Mitochondrial DNA B Resour, 2019 Dec 18;5(1):348-350.
PMID: 33366551 DOI: 10.1080/23802359.2019.1704637

Corvus macrorhynchos formerly referred to as the jungle crow or the large-billed crow is a polytypic species with unresolved taxonomy, comprising various subspecies widespread across South, Southeast, and East Asia. In this study, we report the complete mitogenome of one of these subspecies, Corvus macrorhynchos intermedius (Himalaya crow), from Pakistan. The mitochondrial genome is circular, 16,927 bp and contains typical animal mitochondrial genes (13 protein-coding genes, 2 ribosomal RNA, and 22 transfer RNA) and one non-coding region (D-loop) with a nucleotide content of A (30.6%), T (24.8%), G (14.8%), and C (29.8%). Phylogenetic analysis using the whole mitochondrial genome showed that C. m. intermedius and only reported subspecies Corvus macrorhynchos culminatus (Indian Jungle crow) are genetically distinct and it supports the recognition of the latter as a separate biospecies.
Fulltext A novel method for the quantification of industrial and municipal waste materials for environmental hazard assessment

Arifin MH, Kayode JS, Ismail MKI, Abdullah AM, Embrandiri A, Nazer NSM, et al.

MethodsX, 2021;8:101182.
PMID: 33365262 DOI: 10.1016/j.mex.2020.101182

A novel methodological approach was developed to quantified the volume of industrial waste desposal (IWD) site, combined with municipal waste materials (MWM), through the integration of a non-invasive, fast, and less expenssive RES2-D Electrical Resistivity Technique (ERT), using Wenner-Schlumberger electrode array geophysical method with Oasis Montaj software. Underground water bearing structures, and the eco-system are being contaminated through seepage of the plumes emanating from the mixtures of the industrial waste materials (IWM), made of moist cemented soil with municipal solid wastes (MSW) dumped at the site. The distribution of the contiminant hazardous plumes emanating from the waste materials' mixtures within the subsurface structural lithological layers was clearly map and delineated within the near-surface structures, using the triplicate technique to collect samples of the soil with the waste mixtures, and the water analysis for the presence of dissolved ions. The deployed method helped to monitor the seepage of the contaminant leachate plumes to the groundwater aquifer units via the ground surface, through the subsurface stratum lithological layers, and hence, estimation of the waste materials' volume was possibly approximated to be 312,000 m3. In summary, the novel method adopted are as presented below:•The novel method is transferable, reproduce-able, and most importantly, it is unambiguous technique for the quantification of environmental, industrial and municipal waste materials.•It helps to map the distribution of the plumes emanating from the waste materials' mixtures within the subsurface structural lithological layers that was clearly delineated within the near-surface structures underlain the study site.•The procedure helped in the monitoring of leachate contaminants plumes seepages into the surface water bodies and the groundwater aquifer units, via the ground surface, through to the porous subsurface stratum lithological layers.
Fulltext Dataset for assessing the efficiency factors in Malaysian ports: Dry bulk terminal

Rozar NM, Razik MA, Sidik MH, Kamarudin S, Ismail MR, Azid A, et al.

Data Brief, 2020 Aug;31:105858.
PMID: 32637478 DOI: 10.1016/j.dib.2020.105858

This research paper provides for the identification of dry bulk terminal efficiencies on the basis of 10 key performance factors in Malaysian ports. Data were collected from 18 dry bulk ports in Malaysia in 2017 through an online questionnaire and distributed via e-mail. The dispersion of the respondents corresponds approximately to the structure of the Malaysian maritime terminal in dry bulk. The data provides port management perceptions towards 10 variables that have been surveyed. Each perception assessed the level of efficiency factors based on a percentage rate of 100%. Efficiency factors in dry bulk terminals have been identified with varying characteristics based on a descriptive analysis table. The dataset presented consists of a brief analysis of all 10 variables involved, including the minimum, maximum, mean, interquartile median and standard deviation. In addition to the descriptive analysis, the normality test and histogram were also performed. Data can be used to measure ports-efficiency factors in another research.
The Roles of Tissue Rigidity and Its Underlying Mechanisms in Promoting Tumor Growth

Zakaria MA, Rajab NF, Chua EW, Selvarajah GT, Masre SF

Cancer Invest, 2020 Sep;38(8-9):445-462.
PMID: 32713210 DOI: 10.1080/07357907.2020.1802474

Tissues become more rigid during tumorigenesis and have been identified as a driving factor for tumor growth. Here, we highlight the concept of tissue rigidity, contributing factors that increase tissue rigidity, and mechanisms that promote tumor growth initiated by increased tissue rigidity. Various factors lead to increased tissue rigidity, promoting tumor growth by activating focal adhesion kinase (FAK) and Rho-associated kinase (ROCK). Consequently, result in recruitment of cancer-associated fibroblasts (CAFs), epithelial-mesenchymal transition (EMT) and tumor protection from immunosurveillance. We also discussed the rationale for targeting tumor tissue rigidity and its potential for cancer treatment.
Prediction of sediment heavy metal at the Australian Bays using newly developed hybrid artificial intelligence models

Bhagat SK, Tiyasha T, Awadh SM, Tung TM, Jawad AH, Yaseen ZM

Environ Pollut, 2021 Jan 01;268(Pt B):115663.
PMID: 33120144 DOI: 10.1016/j.envpol.2020.115663

Hybrid artificial intelligence (AI) models are developed for sediment lead (Pb) prediction in two Bays (i.e., Bramble (BB) and Deception (DB)) stations, Australia. A feature selection (FS) algorithm called extreme gradient boosting (XGBoost) is proposed to abstract the correlated input parameters for the Pb prediction and validated against principal component of analysis (PCA), recursive feature elimination (RFE), and the genetic algorithm (GA). XGBoost model is applied using a grid search strategy (Grid-XGBoost) for predicting Pb and validated against the commonly used AI models, artificial neural network (ANN) and support vector machine (SVM). The input parameter selection approaches redimensioned the 21 parameters into 9-5 parameters without losing their learned information over the models' training phase. At the BB station, the mean absolute percentage error (MAPE) values (0.06, 0.32, 0.34, and 0.33) were achieved for the XGBoost-SVM, XGBoost-ANN, XGBoost-Grid-XGBoost, and Grid-XGBoost models, respectively. At the DB station, the lowest MAPE values, 0.25 and 0.24, were attained for the XGBoost-Grid-XGBoost and Grid-XGBoost models, respectively. Overall, the proposed hybrid AI models provided a reliable and robust computer aid technology for sediment Pb prediction that contribute to the best knowledge of environmental pollution monitoring and assessment.
Fulltext Huge Retroperitoneal Cyst Masquerading as Ovarian Tumour: A Case Report

Johan S, Hassan MF, Hayati F, Azizan N, Payus AO, Edwin See UH

Front Surg, 2020;7:585411.
PMID: 33195391 DOI: 10.3389/fsurg.2020.585411

Retroperitoneal cystic mass is a rare surgical condition that is often misdiagnosed preoperatively. Here, we report a case of a 56-year-old woman who presented with abdominal swelling for a 1-year duration, which was associated with lower abdominal pain for 6 months. Her abdominal radiograph showed a huge radiopaque lesion, and contrast-enhanced computed tomography scan of the abdomen reported it as a left ovarian serous cystadenoma causing local mass effect to the left ureter leading to mild left hydronephrosis. She underwent exploratory laparotomy and noted there was a huge retroperitoneal cystic mass. The histopathological assessment finding was consistent with a benign retroperitoneal cyst. This case report aims to share the rare case of primary retroperitoneal lesions, which can cause a diagnostic challenge preoperatively to all clinicians despite advanced achievement in medical imaging.
Fulltext Fabrication of Bio-Based Gelatin Sponge for Potential Use as A Functional Acellular Skin Substitute

Arif MMA, Fauzi MB, Nordin A, Hiraoka Y, Tabata Y, Yunus MHM

Polymers (Basel), 2020 Nov 13;12(11).
PMID: 33202700 DOI: 10.3390/polym12112678

Gelatin possesses biological properties that resemble native skin and can potentially be fabricated as a skin substitute for full-thickness wound treatment. The native property of gelatin, whereby it is easily melted and degraded at body temperature, could prevent its biofunctionality for various applications. This study aimed to fabricate and characterise buffalo gelatin (Infanca halal certified) crosslinked with chemical type crosslinker (genipin and genipin fortified with EDC) and physicaly crosslink using the dihydrothermal (DHT) method. A porous gelatin sponge (GS) was fabricated by a freeze-drying process followed by a complete crosslinking via chemical-natural and synthetic-or physical intervention using genipin (GNP), 1-ethyl-3-(3-dimethylaminopropyl) (EDC) and dihydrothermal (DHT) methods, respectively. The physicochemical, biomechanical, cellular biocompatibility and cell-biomaterial interaction of GS towards human epidermal keratinocytes (HEK) and dermal fibroblasts (HDF) were evaluated. Results showed that GS had a uniform porous structure with pore size ranging between 60 and 200 µm with high porosity (>78.6 ± 4.1%), high wettability (<72.2 ± 7.0°), high tensile strain (>13.65 ± 1.10%) and 14 h of degradation rate. An increase in the concentration and double-crosslinking approach demonstrated an increment in the crosslinking degree, enzymatic hydrolysis resistance, thermal stability, porosity, wettability and mechanical strength. The GS can be tuned differently from the control by approaching the GS via a different crosslinking strategy. However, a decreasing trend was observed in the pore size, water retention and water absorption ability. Crosslinking with DHT resulted in large pore sizes (85-300 µm) and low water retention (236.9 ± 18.7 g/m2·day) and a comparable swelling ratio with the control (89.6 ± 7.1%). Moreover no changes in the chemical content and amorphous phase identification were observed. The HEK and HDF revealed slight toxicity with double crosslinking. HEK and HDF attachment and proliferation remain similar to each crosslinking approach. Immunogenicity was observed to be higher in the double-crosslinking compared to the single-crosslinking intervention. The fabricated GS demonstrated a dynamic potential to be tailored according to wound types by manipulating the crosslinking intervention.
Fulltext Key Teacher Attitudes for Sustainable Development of Student Employability by Social Cognitive Career Theory: The Mediating Roles of Self-Efficacy and Problem-Based Learning

Liu X, Peng MY, Anser MK, Chong WL, Lin B

Front Psychol, 2020;11:1945.
PMID: 33117202 DOI: 10.3389/fpsyg.2020.01945

Higher education policy and talent training are failing to meet the ever-changing expectations of employers and society in Taiwan, resulting in a gap between university education and employment. This study used social cognitive career theory (SCCT) to explore the relationships among self-efficacy, transformational leadership (TL), student employability (SE), and problem-based learning (PBL) in higher education institutions (HEIs). The analysis of 637 undergraduates from 16 Taiwanese HEIs using structural equation modeling (SEM) shows significant positive correlations among self-efficacy, PBL, TL, and SE, with PBL and self-efficacy as key mediators. Based on these findings, the researchers propose feasible suggestions for related issues and future research.
Fulltext Photovoltaic modules evaluation and dry-season energy yield prediction model for NEM in Malaysia

Islam SZ, Othman ML, Saufi M, Omar R, Toudeshki A, Islam SZ

PLoS One, 2020;15(11):e0241927.
PMID: 33180779 DOI: 10.1371/journal.pone.0241927

This study analyzes the performance of two PV modules, amorphous silicon (a-Si) and crystalline silicon (c-Si) and predicts energy yield, which can be seen as facilitation to achieve the target of 35% reduction of greenhouse gases emission by 2030. Malaysia Energy Commission recommends crystalline PV modules for net energy metering (NEM), but the climate regime is a concern for output power and efficiency. Based on rainfall and irradiance data, this study aims to categorize the climate of peninsular Malaysia into rainy and dry seasons; and then the performance of the two modules are evaluated under the dry season. A new mathematical model is developed to predict energy yield and the results are validated through experimental and systematic error analysis. The parameters are collected using a self-developed ZigBeePRO-based wireless system with the rate of 3 samples/min over a period of five days. The results unveil that efficiency is inversely proportional to the irradiance due to negative temperature coefficient for crystalline modules. For this phenomenon, efficiency of c-Si (9.8%) is found always higher than a-Si (3.5%). However, a-Si shows better shadow tolerance compared to c-Si, observed from a lesser decrease rate in efficiency of the former with the increase in irradiance. Due to better spectrum response and temperature coefficient, a-Si shows greater performance on output power efficiency (OPE), performance ratio (PR), and yield factor. From the regression analysis, it is found that the coefficient of determination (R2) is between 0.7179 and 0.9611. The energy from the proposed model indicates that a-Si yields 15.07% higher kWh than c-Si when luminance for recorded days is 70% medium and 30% high. This study is important to determine the highest percentage of energy yield and to get faster NEM payback period, where as of now, there is no such model to indicate seasonal energy yield in Malaysia.

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