Pusat Pengajian Sains Kesihatan - Tesis

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A lahore birth cohort study (LBCS): analysis of the growth and development of Pakistani infants in relation to the nutritional status of their mother and associated risk factors after birth
(2024-05)
Amjad, Safeena
In Pakistan, the prevalence of child malnutrition is higher than in other developing countries. Lahore Birth Cohort Study (LBCS) was conducted to analyze the association between the health and growth of Pakistani infants with maternal nutritional status, depression, and dietary patterns after delivery. The LBCS was a two-year prospective cohort study started in 2020 that recruits Pakistani Infants after their birth from the Punjab Medical Centre Lahore Pakistan. Participants of the study were interviewed three times at birth, at 2.5 months, and at the age of 9 months. The mother’s postpartum information was collected from the hospital records and via a pre-structured questionnaire. Collected data included sociodemographic features, anthropometrics of newborns and mothers, dietary intake of mothers during pregnancy, infant feeding practices after birth, and 2.5 months along with breastfeeding and weaning practices at the age of 9 months. Findings indicate that the continuation of maternal breast milk during the first six months of life protects infants from various forms of malnutrition. It was also found that maternal factors such as postpartum depression (P<0.017) and mother’s occupation (P<0.04) have a significant association with the infant’s growth and development. It was also determined that breastfeeding (P<0.018), bread and cereals (P<0.00), dairy and dairy products (P<0.015), other milk (P<0.00), and meat and meat substitutes (P<0.00) also has a potentially significant association between the variables at 9 months. The correlation coefficient revealed that there is a positive association between postpartum depression and postpartum BMI on infant birth weight for the age Z score, birth weight (percentile), birth height for the age z score, and birth head circumference (percentile). There was a significant correlation between breastfeeding and infant anthropometric measurements at 2.5 and 9 months of age, including length, weight for age, and head circumference percentile. The strength of these associations increased by 9 months, indicating that breastfeeding's effect on growth parameters persists and even intensifies as infant grows. In conclusion, the Lahore Birth Cohort Study contributes crucial insights into the multifaceted relationship between breastfeeding, maternal factors, and infant growth. The findings emphasize the persistent and intensifying impact of breastfeeding, guiding healthcare recommendations and underlining the need for holistic support for infant health in the Pakistani context.
A methodology building for multilayer feed-forward neural network (MLFFNN): an application in biometry modelling
(2023-04)
Adnan, Mohamad Nasarudin
This research aims to develop a hybrid method for Multi-Layer Feed-Forward Neural Network (MLFFNN) with two different approaches; (i) Multiple Logistic Regression (MLogisticR) for the first method, (ii) Multiple Linear Regression (MLinearR) for the second method. The developed hybrid method is based on bootstrap, regression, and MLFFNN. In the first method, the accuracy of the developed method is measured based on the value of the Mean Squared Error Neural Network (MSE.net), Mean Absolute Deviance (MAD), and the accuracy percentage. While for the second method, Mean Squared Error Neural Network (MSE.net) and R2 will be used to evaluate the performance of the proposed method. All those components serve as a yardstick to determine the accuracy and efficiency of the developed model. Existing software only produces limited results. The main focus of this study is the need for better decision-making with solid evidence. The main goal of this research is to build a hybrid method and generate a numerical result and visualization (graphical representation). The results from both case studies show that the hybrid method has successfully improved the accuracy, effectiveness, and efficiency of parameter estimation in the final results of the analysis. The findings of this study contribute to the development of a comprehensive research methodology in future and suggest more accurate results for the decision-making process.
A monitoring of archery performance predictors among state-level archers
(2023-09)
Sien, Lau Jiun
Archery is a sport that required a certain level of techniques, physical conditions, tactics, and psychology to perform. It is important to understand the most crucial criteria in archery to build excellent archers. Thus, this study aimed to determine the predictors of archery performance among state-level recurve archers. Eighteen state-level recurve archers were recruited from Terengganu State Sports Council and Malaysia Pahang Sports School and 13 participants (mean age = 16.23 ± 1.74) had completed the whole study protocol. Muscle activation level, draw force line, mood states, and physical fitness level of the archers were monitored predictors of archery performance in this research. The mood states of the participants were evaluated with Brunel Mood Scale Questionnaire before the scoring session. During the scoring session, the muscle activation of left deltoid muscles, left triceps muscles, right trapezius muscles, and right triceps muscles were measured with electromyography. Meanwhile, the draw force line during the anchoring and releasing was recorded with a video camera and was analysed with Kinovea motion analysis software. The archery shooting performance was based on a total score of 36 arrows shot at a distance of 70 meters. After the scoring session, the physical fitness level of the participants was measured with fitness tests including push-ups, sit-ups, handgrip test, stork stand test, back and leg test, sit and reach test, and multistage fitness test. All the parameters were measured five times, with each measurement taken at a twomonths interval. The results of the Multiple Linear Regression (MLR) revealed muscle activation level and physical fitness level can be used as a guideline in predicting the archery shooting performance. Among the muscles tested in this study, the left deltoid is the only muscle that is associated with the archery shooting performance in the fifth measurement session. Furthermore, physical fitness level also able to predict the shooting performance significantly in the first measurement session, third measurement session and forth measurement session. The physical fitness components that were associated with the archery shooting performance included left and right handgrip strength, back and leg strength, flexibility, balance, upper muscle endurance, core muscle endurance, and cardiovascular endurance. However, the mood states and the draw force line of participants are not associated with the archery performance. It is concluded that the physical fitness level and muscle activation level of the archers can predict the archery shooting performance among state-level archers.
A prospective case-control study on nutritional status and lifestyle risk factors towards quality of life among colorectal cancer and polyp patients in Malaysia
(2025-08)
Ashari, Lydiatul Shima
In Southeast Asian countries, there is a growing incidence and prevalence rate of disease-related malnutrition colorectal cancer (CRC) and its precursor, colorectal polyp, however there are only few reports of this condition. Treatments and the disease itself may affect and impair the overall quality of life (QOL) of CRC survivors. The study aimed to determine the nutritional status and lifestyle risk factors among CRC and polyp patients and their impact on QOL through a prospective case-control study in Malaysia. This study was conducted in two university hospitals in Peninsular Malaysia from June 2020 until December 2022. Patients were recruited through purposive sampling method and a total of 313 patients consisting of 99 and 74 pathologically confirmed CRC and colorectal polyp cases respectively, and 140 controls were included in the analysis. The following information was gathered pre- treatment: Socio-demographic, family and personal medical history, dietary intake, sedentary behaviour, nutritional risk, smoking, clinicopathological, biochemical parameters, and anthropometric profiles. Six months post-treatment, sedentary behaviour, nutritional risk, biochemical parameters, and anthropometric profiles were gathered again, together with treatment and QOL. Multiple logistic regression model revealed that the Kuala Lumpur state (OR=8.89, 95% CI=3.19-24.83; p<0.001), type 2 diabetes mellitus (T2DM) (OR=4.91, 95% CI=1.81-13.29, p=0.002), vitamin/mineral supplements (OR=5.15, CI=2.33-11.39, p<0.001), and saturated fatty acids (SFA) (OR=1.19, 95% CI=1.08-1.31, p<0.001) intake were associated with greater risks of CRC while non-Malay (OR=0.36, 95% CI=0.15-0.87, p=0.024), overweight (OR=0.14, 95% CI=0.04-0.48, p=0.002), increased intake of vitamin D (OR=0.71, 95% CI=0.55-0.92, p=0.008) and dietary fibre (OR=0.81, 95% CI=0.74-0.89, p<0.001) were associated with reduced risk of CRC after the data were adjusted for age and gender. For colorectal polyp, the Kuala Lumpur state (OR=4.36, 95% CI=2.02-9.41, p<0.001) and high cholesterol (OR=1.003, 95% CI=1.001-1.005, p=0.006) intake were associated with increased risk while high thiamin (OR=0.02, 95% CI= 0.00-0.11, p<0.001) and fruits (OR=0.997, 95% CI=0.995-1.000, p=0.035) intake were found associated with decreased of risk. Multiple linear regression model showed that malnourish (β=-18.40, p<0.001) and abdominal obesity (β=-10.07, p=0.020) were negatively associated with QOL after six months of post-treatment. This study advances current understanding of the nutritional and metabolic pathways underlying colorectal cancer and polyp development, providing a foundation for future mechanistic and intervention studies
A standardised fraction 1 (SF1) from clinacanthus nutans attenuates the stemness of cervical cancer stem-like cells via inhibition of notch1 signalling
(2024-09)
Ismail, Faridah
Cancer stem cells (CSCs) represent a tiny subset of cancer cells characterised by deregulated self-renewal, aberrant stemness signalling pathways, and a high tumorigenic potential. Mounting evidence indicates that CSCs play a critical role in cancer growth, metastasis, relapse, and resistance to radiotherapy and chemotherapy. Hence, targeting CSCs will provide novel treatments for cancer. Clinacanthus nutans (C. nutans), or locally known as Sabah snake grass (‘daun belalai gajah’), is a well reputed medicinal herb in East Asia that has shown promising anticancer activities in a range of cancer cell types. However, no study has reported its effect on CSCs. Therefore, this study was conducted to determine the antitumour effect of SF1, a semi-purified fraction from C. nutans, on CSCs derived from cervical cancer (CCSCs) and the underlying mechanisms. Bioassay guided fractionation was employed for the isolation of SF1 from C. nutans leaf extract. The SiHa cell line was used for the enrichment of CCSCs by culturing the cells in CSC-conditioned medium (cervospheres). Stemness characterisation of the cervospheres was performed using a sphere formation assay and flow cytometric analysis of the stem-related markers, including CD49f, CK17, Sox2, Nanog, and Oct4. The cervospheres were then subjected to SF1 treatment, and cisplatin was used as a positive control. The antitumour effects of SF1 on cervospheres were evaluated by assessing cell viability, sphere-forming efficiency, and tumorigenic capacity using the OZ blue cell viability kit, sphere formation assay, and in vivo tumorigenicity assay, respectively. The mechanisms by which SF1 eliminated CCSCs were determined by evaluating the selected stemness marker expressions via flow cytometry. Additionally, Notch1 signalling activity, a key regulator for CSC self-renewal and tumorigenicity was examined using the Western blot, quantitative reverse transcriptase PCR (RT-qPCR), and immunohistochemistry staining assays. The results of the study showed that SiHa derived cervospheres exhibited high sphere-forming efficiency, and increased expressions of the stemness markers. In addition, further investigation revealed that these cells possessed higher tumorigenicity in nude mice and increased levels of Notch1 protein and gene expression compared to the parental SiHa monolayer cells. SF1 effectively inhibited the cervosphere viability and stemness phenotypes in vitro and in vivo. SF1 was found to induce a concentration-dependent cytotoxicity in the cells, with a half-maximal inhibitory concentration (IC50) of 17.07 µg/ml. Additionally, treatment of cervospheres with SF1 at the IC50 dose for 72 hours resulted in a significant reduction in the sphere-forming efficiency and a suppression of tumour growth in xenotransplant mice. Besides, SF1 decreased the expression of stemness markers in the cervospheres, primarily CK17 and Sox2 expressions. Nevertheless, Nanog expression remained unaffected. Apart from that, the inhibition of cervosphere stemness properties was accompanied by a marked decrease in the level of Notch1 protein expression. In contrast, increased expression of the Notch1 gene was noted. This implies that SF1 may act by promoting proteasomal degradation of Notch1 protein or disrupting its translation process. In conclusion, SF1 possesses antitumor activity against SiHa derived CSCs, which was achieved through attenuation of their stemness properties and inhibition of the Notch1 signalling. Hence, SF1 may serve as a prospective therapeutic agent for improving cervical cancer management.
An integrated Raman spectroscopy and self-organizing feature map chemometrics analysis for the discrimination of gel inks
(2022-07)
Asri, Muhammad Naeim Mohamad
One of the techniques often used by forensic document examiner in the analysis of questioned documents is Raman spectroscopy. This technique has proven effective in rapidly and accurately characterising ink with the advantage of not causing permanent damage to the analysed document. Gel ink pen was first introduced to the market around 1990s by the Sakura Colour Product Corporation, Japan as an alternative daily writing instrument other than ballpoint-pen. Being marketed in varieties of attractive colours and also environmentally friendly, gel ink pen has become very popular among consumers therefore it appearances in cases involving document fraud is anticipated. Unfortunately, studies involving gel ink pen in the perspective of questioned document are limited compared to ball-point pen. In forensic investigation, it was reported that 80% handwritten documents were written using ballpoint pens. Therefore, due to the lack of objectivity in interpreting gel inks, this study proposed using novel chemometric techniques for discriminating gel-pen inks in forensic investigation. This study show the comprehensive conceptual work flow with conventional chemometrics techniques of Principal Component Analysis (PCA), Hierarchical Cluster Analysis (HCA) and novel Self-Organising Feature Maps (SOFM) in tandem with Raman spectroscopy to discriminate gel inks of three different colours i.e. blue, red and black before and after undergoing ageing process for nearly three years. Preliminary dissolution studies performed by dissolving gel inks in a varieties of organic solvents show that gel inks of pigment based colourants do not normally dissolve in organic solvents while Thin Layer Chromatography (TLC) is only successful to dye-based colourant gel inks. Queries made to the acquired blue, red and black gel inks Raman spectra against a database containing Raman spectra of 200 pigments, suggested that CI Pigment Blue 15: 1 and 15: 3, could be the main pigment in blue gel inks conversely Red DPP BO (23180 – CI Pigment Red) and XSL Poppy Red (26308 – CI Pigment 112) could be the main pigment in red gel inks however main pigments in black gel inks remain unidentified. In most cases, Hierarchical Cluster Analyses (HCA) have recorded lesser number of clusterings compared to Principal Component Analyses (PCA). In general, both conventional chemometrics techniques are unable to discriminate the gel inks according to their brands however this is not the case for the novel SOFM. All SOFM maps are in line with the classification made by the visual Raman comparison of inks. The misclassified sample (HCA and PCA) was successfully resolved using the SOFM model signifying its capability for both discrimination and classification purposes. Cross validations employing the k-validation strategy have recorded 100% correct classification rates for all the SOFM models, thus signifies the robustness and potential of SOFM for discrimination of gel inks. As for the aged gel inks, SOFM has also successfully sourced the aged inks to their fresh counterparts. This study reported the first use of SOFM for discrimination and classification of gel inks. The findings of this study did not only communicate the comprehensive work flow for gel ink analysis but most importantly signify the potential of SOFM to be employed in tandem with Raman spectroscopy as an alternative pattern recognition technique to the conventional chemometrics techniques that can be highly useful in document fraud investigation involving gel inks.
Antibacterial activity and mechanisms of action of the semi-purified fractions from melaleuca cajuputi leaves against selected bacterial strains
(2024-06)
Musa, Isah
The increasing incidence of bacterial infections and the rapid spread of antimicrobial resistance underscores the need to find novel alternative medications from natural sources, especially medicinal plants. Thus, this study aimed to investigate the antibacterial activities of Melaleuca cajuputi leaf extract and unveil the possible antibacterial mechanisms of the most potent semi-purified fractions against selected bacterial strains. The mineral content in M. cajuputi leaf was analyzed using inductively coupled plasma-mass-spectrometry (ICP-MS). Methanolic, ethanolic, and aqueous extracts were obtained by cold maceration. Subsequently, the most potent crude extract was fractionated to obtain semi-purified fractions by bioassay-guided fractionation technique. The antibacterial activity of the crude extracts and semi-purified Melaleuca fractions (MFs) was evaluated using a broth microdilution assay. Ultraviolet-visible (UV-Vis), Fourier transform infrared (FTIR) spectroscopies, and gas chromatography-mass spectrometry (GC-MS) were employed to identify the chemical compositions of the most potent extract and semi-purified MFs. Mechanisms of action of the most potent MFs were investigated using time-kill assay, cell morphology examination, and in-silico molecular docking studies. The toxicity profile was evaluated using the brine shrimp lethality test (BSLT). Macronutrients such as potassium (7182.042 mg/kg), sodium (3895.795 mg/kg), calcium (3730.259 mg/kg), and trace elements including iron (89.394 mg/kg), manganese (57.070 mg/kg), and zinc (51.626 mg/kg) were detected in M. cajuputi leaf extract. The antibacterial assays demonstrated that MF2c and MF2d were the most potent, with minimum inhibitory concentration (MIC) values ranging from 0.13 mg/mL to 0.25 mg/mL and 0.063 mg/mL to 0.25 mg/mL, respectively. The bioactive compounds identified in MF2c were β-eudesmol (71.96%), α-eudesmol (18.83%), and γ-eudesmol (9.21%). Meanwhile, 2-isopropyl-10-methylphenanthrene (83.09%), 10-methylanthracene-9-carboxaldehyde (10.95%), trimethyl gallic acid (2.60%), methyl-lathodoratin (2.10%), and methoxyamine (0.28%) were identified in MF2d. Time-kill assay revealed that MF2c and MF2d exhibited concentration-dependent bactericidal effects against the tested bacterial strains. The scanning electron micrographs of the treated bacteria showed apparent cell membrane damage characterized by abnormal cell elongation, shrinkage, and organic debris on the cell surfaces. Furthermore, the in-silico molecular docking analysis revealed that 2-isopropyl-10-methylphenanthrene had the highest binding propensity against DNA-dependent RNA polymerase, D-alanyl transferase, DNA gyrase, and dihydropteroate synthase, with docking energy scores of -8.4, -6.9, -6.5, and -6.1 kcal/mol respectively. Based on the toxicity results, M. cajuputi methanolic extract (LC50 781 μg/mL showed mild toxicity, whereas MF2c (LC50 6621 μg/mL) and MF2d (LC50 1165 μg/mL) were non-toxic. In conclusion, the semi-purified MFs showed remarkable antibacterial effects and were non-toxic. The findings hold promise for developing alternative therapeutic strategies to combat bacterial infection
Antibiotic resistance during covid-19 pandemic and perspective of healthcare providers towards antibiotic resistance: a mixed-method study
(2024-02)
Sulayyim, Hadi Jaber Al
During the Novel coronavirus disease 2019 (COVID-19), there was an overuse of antibiotics in hospitals. The improper use of antibiotics during COVID-19 has increased the antibiotic resistance (AR), which was reported by multiple studies. The main objective of this study was to study the AR during COVID-19 and perspective of healthcare providers towards AR. This study employed a mixed method design throughout two phases. Phase Ⅰ study (ⅰ): A retrospective cross-sectional study was employed to identify patients who had positive AR bacteria before, during and after COVID-19 as well as the bacterial isolates; Phase Ⅰ study (ⅱ): A cross sectional design was employed to assess the knowledge, attitude, and practice (KAP) of healthcare worker (HCWs) in Najran, Kingdom of Saudi Arabia (KSA); Phase Ⅱ study: A qualitative multi-centre study was carried out in the KSA to explore the experience of health commissioners toward AR during COVID-19. Results of Phase Ⅰ study (ⅰ) showed the prevalence of Pan Drug Resistance (PDR) during COVID-19 pandemic (85.7%) was higher as compared to the time before (0%) and after (14.3%), p= 0.001. S. aureus showed a negligible resistance after pandemic, while the resistance Gramnegative bacteria decreased during and after pandemic compared to the time before. Results of Phase Ⅰ study (ⅱ) revealed poor knowledge, negative attitude and poor practice of HCWs. The significantly associated factors with good knowledge were nationality, cadre, qualification, and working place. Positive attitude was significantly associated with cadre, qualification, and working place. Good practice was significantly associated with gender, cadre, qualification, and working place. In Phase Ⅱ, seven themes emerged from data. Therefore, despite the AR increased globally during COVID-19 pandemic, it dropped gradually in Najran region, KSA. Knowledge, attitude and practice of HCWs in Najran, KSA regarding AR during pandemic need improvement, whereas healthcare commissioners showed scientific and up to date knowledge about the AR. Antibiotics’ prescription should be strictly implemented, relying on the antimicrobial stewardship programs (ASP) and guidelines from the world health organization (WHO) or ministry of health (MOH). Implementation of effective educational and training programs are urgently needed. Findings of this study could be used to inform policy and practice for governmental HCWs and public to reduce the impact of pandemics on the AR.
Antimicrobial susceptibility and molecular profiles of acinetobacter baumannii in Makkah hospitals, and the potential use of bacteriophage as a treatment option
(2022-12)
Raees, Fahad
Acinetobacter baumannii is an opportunistic Gram-negative pathogen that frequently causes infections especially in intensive care settings worldwide including Saudi Arabia. This organism is known to acquire resistant to almost all clinically available antimicrobial agents. To understand the magnitude of A. baumannii acquisition in local settings, 895 isolates were collected from King Abdullah Medical City Makkah, Al Noor Hospital and Al Zahir Hospital of Makkah from 2013-2019. Vitek2® system was used for identification of the organism and antimicrobial susceptibility test. Thirty MDR A. baumannii isolates from King Abdullah Medical City Makkah and seven from Al Noor Hospital were selected for whole genome sequencing. To study the role of bacteriophage, sewage water from King Abdullah Medical City Makkah and Al Noor Hospital were screened for clinical isolates A. baumannii lytic phenomenon. A few bacteriophage candidates were found, but the subsequent lytic tests were negative. This phenomenon was studied by reviewing the bacteriophage genomes integrated in the bacterial nucleic acids. In this study, 70-80% of A. baumannii isolated from Makkah hospitals were found to be resistant to commonly used antibiotics in intensive care units. There are increasing trends of resistance to agents that been reserved to treat carbapenem-resistant A. baumannii i.e. tigecycline and colistin. The sequence type (ST)-195 was the predominant sequence type, contributed to 48.6% of A. baumannii isolations in Makkah hospitals. There were three novel sequence types that associated with 18.9% of infections that need further characterization. Among the β-lactamase resistant mutations, this study found blaADC-25 and blaOXA-66 were the most common with 86.5% and 83.8% respectively, followed by blaOXA-23 and blaTEM-1D, both at 37.8%. This study also found 75.7% and 73.0% of the tested MDR A. baumannii isolated from Makkah hospitals acquired mph(E) and msr(E) macrolides resistant genes respectively. The aminoglycosides resistance was encoded mainly by aminoglycoside phosphor-transferase gene, aph(3′′)-Ib at 83.8% and aminoglycoside O-phosphotransferase aph(6)-Id at 70.3%. Besides, these MDR isolates were also acquired of sulphonamide resistant genes of sul1 (32.4%) and sul2 (18.9%). Part of the core of this project was to find the potential bacteriophage that has capability to infect and lyse A. baumannii cells. After extensive searching for bacteriophage from sewage water of two tertiary care hospitals in Makkah, several bacteriophage candidates were shortlisted, however these bacteriophages failed to perform lytic phenomenon consistently. Almost one-fourth of MDR A. baumannii were found to acquire intact bacteriophage genomes, indicated prophages condition. The whole genome sequence of two MDR A. baumannii isolates (AB417 and AB552) were studied before and after bacteriophage treatment indicated additional intact bacteriophage genomes were added in isolate AB552. Three genomes of non-Acinetobacter bacteriophages was found to be integrated in these MDR Acinetobacter series. In conclusion, this study found the resistant rate of A. baumannii were more than 80% in Makkah hospitals which may lead to treatment failure in clinical practice. Searching for a non-pharmacological approach by means of using bacteriophage therapy showed inconsistent outcomes. With few treatment options available, robust infection control strategies and antibiotic stewardship programs are critical for preventing the spread of these resistant strains. Further research is very critical to find alternative agents to treat MDR A. baumannii.
Application of eggshells and seashells for latent fingermark development.
(2025-09)
Said, Nur Fatin Nabihah
Fingerprint identification remains an essential aspect in the field of forensic science, being a reliable tool for identifying suspects and reconstructing criminal events. The current research explores the possibility of producing fingerprint powders from eggshells (ES) and seashells (SS), two widely available biowaste products that are mainly made up of calcium carbonate. The characterisation of ES and SS powders using FTIR, SEM, and EDX methods demonstrated that both the magnetic and non-magnetic types are efficient green alternatives for the development of latent fingermarks. The magnetic type is especially suitable for application on sensitive or valuable surfaces. A Friedman test revealed considerable differences in the development of latent fingermarks among the various powders, with a p-value noted at less than 0.001. Magnetic eggshell powder (MES) proves to be the best natural alternative for use on non-porous surfaces, exhibiting a durability profile that allows for multiple recovery attempts. Magnetic seashell powder (MSS) exhibited the most consistent detail in microscopic ridge patterns, showing great potential as an eco-friendly substitute for commercially magnetic powders in the development of latent fingermarks rich in amino acids, cholesterol, and squalene on non-porous surfaces. Non-magnetic ES and SS powders performed well in the case of DL-serine-based deposits. MES and MSS powders showed great promise as environmentally friendly alternatives to palmitic acid-based fingerprints. In addition, both magnetic and non-magnetic variants exhibited the most pronounced ridge definition for lactic acid-rich fingerprints, indicating their great potential for the development of hydrophilic residues. The Kruskal-Wallis test showed that the type of powder did not significantly affect fingermark scores for either heat ageing (p = 0.998) or submersion ageing (p = 0.903). This means that fingermark development was similar across all powder types in both conditions. In contrast, fingermark scores varied significantly among the ten surface types examined (p < 0.001 for both ageing studies). Natural powders derived from ES and SS, especially their magnetic forms, had shown competitive, and often better, performance than commercial powder under water exposure. On the other hand, their non-magnetic powder had proven to be remarkably resilient under different conditions, especially when subjected to high heat. In summary, this research offers valuable information on the forensic process relating to natural resource powders, moving the field towards a green and safe method for latent fingermark visualisation
Application of geometric morphometric (GMM) approach for author’s ethnicity discrimination using the handwritten numeral characters
(2024-03)
Taufek, Wan Nurul Syafawani Wan Mohd
Handwriting is unique in which no two individuals can write the same way regardless they are identical or fraternal twins. Everyone has their own unique handwriting style or their natural handwriting variations which are influenced by a variety of factors which include their ethnic background or cultural background. Nonetheless, discriminating individuals’ ethnicity based on their handwriting characters, let alone the handwritten numeral characters, is limited even though the handwritten numeral characters analysis can be crucial in assisting forensic document examiner (FDE) in solving crimes related to dubious documents. The general objective of this study was to investigate whether it is possible to discriminate authors based on their ethnic background by utilising their handwritten numeral characters using novel Geometric Morphometric (GMM) technique. The handwritten numeral characters of 0 until 9 were collected from 390 participants from three different ethnic backgrounds in Malaysia which had been digitised and landmarked using TpsUtil1.78 and TpsDig2 software respectively, prior to GMM assessment using MorphoJ and Minitab software. From the results, two-dimensional (2D) and three-dimensional (3D) of Principal Component Analysis (PCA) scatterplots demonstrated identifiable cluster patterns between Malay, Chinese and Indian authors. Besides, there were significant differences in the handwritten numerals 2 through 9 between Malay, Chinese and Indian authors when the datasets tested using Procrustes Analysis of Variance (ANOVA) (p<0.0001) and Discriminant Function Analysis (DFA) (p<0.0001), which that these handwritten numeral characters have potential to be used to discriminate authors based on their ethnicities.
Biospectroscopy with chemometrics analysis of blood for species identification and age estimation
(2024-08)
Sandran, Durga Devi
Accurate species identification and age estimation of bloodstains are indispensable tools in forensic investigations, providing invaluable information that can significantly impact case outcomes. However, existing methods are challenging due to their destructive and strenuous procedures. This thesis explores the effectiveness of biospectroscopic techniques and multivariate chemometrics integration for species and age determination of bloodstains, using samples from eight species: humans, cattle, chicken, deer, duck, fish, goat, and swine. The present study deployed tandem analysis of attenuated total reflection-Fourier transform infrared (ATR-FTIR) and ultraviolet-visible (UV/Vis) spectroscopy, complemented by principal component analysis and linear discriminant analysis (PCA-LDA) to determine bloodstain species. The PCA-LDA models for infrared and visible spectroscopy were built and showed complete differentiation between human and animal spectra. The results demonstrated that the ATR-FTIR spectroscopy significantly outperformed visible spectroscopy in discriminating human and animal blood. With a classification accuracy of 98.3%, the infrared PCA-LDA model effectively distinguished between various species, including a perfect classification for humans, chickens, cattle, ducks, and fish. For in-situ bloodstain age analysis, human and animal blood spots were prepared and stored under two conditions: indoors and outdoors. The blood spots were deposited on ten porous and non-porous substrates over one year to simulate a crime scene. Utilising ATR-FTIR spectroscopy, two major blood protein bands (Amides I and II) can be successfully detected in fresh and aged blood spectra for up to one year. A total of 160 partial least squares regression (PLSR) models were developed, with superior predictive performance observed for outdoor bloodstains (RMSE: ~0.29-2.42; R2: ~0.56-0.99) compared to indoor ones (RMSE: ~0.51-3.28; R2: ~0.20-0.98). Lower predictive Root Mean Squared Error (RMSE) and high R² scores for bloodstains on all ten substrates, irrespective of species, enhanced this research's practicality. These models were further applied to create partial least squares-discriminant analysis (PLS-DA) models, demonstrating outstanding categorisation ability up to ~99% (indoors) and ~98% (outdoors) for aged blood spots on porous and non-porous surfaces. Both validation results showed prominent potential and statistically reliable discrimination for estimating the bloodstain age on various substrates, notably for outdoor and longer ageing terms. In summary, this research proves that integrating ATR-FTIR spectroscopy with multivariate chemometrics provides a non-invasive, conclusive and rapid strategy for determining the species and age of bloodstains in forensic investigations with promising practical applications in real cases benefiting the forensic and law enforcement communities.
Caspase-dependent apoptotic mechanism of gallic acid and its derivatives isolated from quercus infectoria ethyl acetate extract against cervical cancer cells lines (hela)
(2023-09)
Ismail, Illyana
Cervical cancer is one of the most common cancers in women worldwide. In 2020, cervical cancer ranked the fourth most diagnosed cancer among Malaysian women. The induction of apoptosis is one of the essential mechanisms to prevent the process of carcinogenesis. The previous study indicated that natural products were able to induce apoptosis and showed promising advantages in cancer treatment. The Quercus infectoria galls (QI) have been reported to have antimicrobial, antioxidant, anticancer and wound healing activities. However, the antiproliferative activity and the underlying molecular mechanisms against human cancer cells have been poorly elucidated. Hence, the present study was undertaken to examine the cell death mechanisms of gallic acid and its derivatives isolated from Quercus infectoria ethyl acetate extract (EAQI) against cervical cancer cells (HeLa). Gallic acid (GA) and its derivative, methyl gallate (MG), were isolated by using a bioassay-guided isolation technique. The antiproliferative effect that characterised by inhibitory concentration at 50 % cell populations (IC50) of EAQI, GA and MG were determined by using the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] assay at various concentration ranging from 0.39 to 100 μg/ml at 72 hours of treatment in HeLa cell lines and the control serving non-cancerous Vero cell lines. Cisplatin was used as a positive control, while untreated HeLa and Vero cells served as the negative control. Changes in cell morphology were measured by acridine orange/propidium iodide (AO/PI) staining for 24, 48 and 72 h. Viable, apoptotic and necrotic cells were identified using a fluorescence microscope. Determination of phosphatidylserine (PS) externalisation was performed using annexin-V Fluorescein isothiocyanate (FITC) / propidium iodide (PI) dual staining assay. The cells were treated for 3, 6 and 12 h and analysed by flow cytometry. Cellular deoxyribonucleic acid (DNA) content was measured in HeLa cells using flow cytometry at 24, 48 and 72 h for cell cycle distribution. Apoptosis pathways were elucidated based on pro and anti-apoptotic protein expressions (p53, Bax and Bcl-2) at 3 hours of treatment and caspases activity (caspase-8 and -9) were analysed by flow cytometry technique at 6 hours of treatment. The results showed that EAQI, MG and GA exhibited the antiproliferative effect on HeLa cells with IC50 values of 11.50 ± 0.5 μg/ml, 11.00 ± 0.58 μg/ml and 10.00 ± 0.67 μg/ml, respectively. In the cell morphology analysis, cells treated with IC50 value of EAQI, MG and GA displayed an increased apoptotic cell population compared to untreated cells (p<0.05) at 72 hours of treatment. The induction of apoptosis was confirmed by the externalisation of phosphatidylserine on early apoptotic cells, which showed the treated cell population shifted from viable to apoptotic quadrant. Based on the cell cycle distribution, the accumulation of cells at the subG0 phase in treated cells indicated the discontinuity of deoxyribonucleic acid DNA fragmentation and led to apoptosis. Furthermore, the results showed that p53 and Bax (pro-apoptotic proteins) were expressed in the treated cells, whereas Bcl-2 (anti-apoptotic protein) was not expressed at 3 hours of treatment. The caspase analysis also revealed that EAQI, MG and GA had induced apoptosis by activating caspase-8 and -9 at 6 hours of treatment. In conclusion, these findings suggested that EAQI, MG and GA significantly induced apoptotic mechanisms via the regulation of intrinsic and extrinsic pathways, which should provide new insight into therapeutic activity and anticancer agents of QI.
Comparative phenomics and genomics of carbapenem-resistant escherichia coli from human and broiler chicken
(2023-07)
Woldegiorgis, Erkihun Aklilu
The emergence of carbapenem-resistant Enterobacterales (CRE) has been alarming, and its control has been considered one of the priorities set by the World Health Organization (WHO). In Malaysia, recent reports show that the prevalence of CRE in general and tertiary hospitals has been alarmingly rising. However, little is known about the occurrence of CRE in animals, particularly food-producing animals such as broiler chickens in Malaysia. Moreover, there is no study on the comparative study of CRE from humans and food animals in Malaysia. Therefore, this study was conducted with the general objective of elucidating the comparative genomics of carbapenem-resistant Escherichia coli (CREC) from humans and broiler chickens. The study was conducted on clinical isolates archives of presumptive CREC isolates (n=32) from Hospital Universiti Sains Malaysia (HUSM), Kubang Kerian, and 384 cloacal swab samples of broiler chickens collected from East Coast Malaysia (Kelantan, Terengganu, and Pahang). Routine bacteriology followed by phenotypic and molecular characterization and determination of molecular epidemiology using multilocus sequence typing (MLST) were conducted. High-throughput Illumina HiSeqTM whole genome sequencing (WGS) of ten selected CREC isolates was done to determine the comparative genomics of the CREC isolates. The assembled genomes were annotated using RASTtk, BAKTA, and eggNOG-Mapper tools, and quantitative and qualitative measurements for ad-hoc downstream analyses were generated using M1CR0B1AL1Z3R server (Microbializer). Analyses of the WGS were done using ResFinder 4.1, VirulenceFinder 2.0, SerotypeFinder 2.0 tool, FimTyper version 1.0 CHTyper 1.0, cgMLST 1.2, pMLST (2.0), CSI Phylogeny, MobileElementFinder, Alien Hunter 1.7, ISFinder and IslandCompare (v1.0). Additional comprehensive genome analyses were done using different genomic analysis pipelines. The results showed an overall CREC detection rate of 7.29% (28/384) which is 10.94% (28) of the 256 E. coli isolated from cloacal swabs of broiler chickens based on phenotypic detection methods. Out of all the CREC, 40% (24/60) of the CREC isolates from human and broiler chickens harbor more than one carbapenemase gene, including the combinations blaNDM+blaOXA-48, blaNDM+blaOXA-48+blaIMP, and blaOXA-48+blaIMP. The molecular typing using MLST showed the detection of ST69, ST131, ST155, ST405, and ST410, which have been recognized as high-risk pandemic lineages. The comparative genomic analyses showed close similarities between CREC isolates from human and broiler chickens, which were evident from almost all the genomic profiles, including phylogeny, genomic islands, SNP analysis, plasmid, serotyping, and cgMLST and other genomic and proteome profiles. The comparative genomic analysis results showing similarities among CREC isolates from humans and apparently healthy chickens are important epidemiological data on CREC in human and broiler chickens in Malaysia. The findings from this study can help in better understanding the local CREC epidemiology and shed light on the possible CRE transmission dynamics in the local context. These findings, in turn, can help in devising of evidence-based control and prevention strategies that can contribute to the national antimicrobial resistance control programs to safe guard the public health.
Comparison of marpe and alt-ramec protocol in correcting skeletal transverse discrepancy in young adults: a randomized controlled clinical trial
(2024-05)
Allam, Amira Hussein Ahmed Mohamed
The skeletal deficiency could be expressed in the maxilla sagittally, vertically, and transversally. The most effective treatment for transverse maxillary deficiency in growing children and adolescents is still rapid maxillary expansion (RME). In adults, mini-screw-assisted rapid palatal expansion (MARPE) proved to be the efficient method for overcoming all dentoalveolar drawbacks. In treating adult patients with anteroposterior deficient maxilla (skeletal class III), the clinician had to decide between an invasive surgical approach to resolve the skeletal imbalance or a camouflage therapy to mask the class III malocclusion. However, in younger patients, alternate rapid maxillary expansion and constriction (ALT-RAMEC) is the treatment of choice. In this study, the 7-week ALT-RAMEC protocol was modified and combined with MARPE to evaluate its efficiency and advantages over conventional MARPE in young adult ages. Twenty-nine patients with transverse maxillary deficiency (mean age of 21.3) were randomly assigned to two groups. The conventional group received MARPE with its conventional rate of expansion, while the ALT-RAMEC group was treated with a combination of MARPE with ALT-RAMEC modified protocol. The efficiency of expansion, circummaxillary sutural displacement, dentoskeletal, respiratory, and clinical periodontal effects were all assessed. Analysis of the change before and after intervention was examined using paired t-tests while analysis of the parameters comparing the two groups was examined using an independent t-test. For variables that were not normally distributed, the p-value was obtained from Bootstrap for pairwise comparison (BCA). The analysis of covariance (ANCOVA) was used when the baseline data was significantly different between groups. The results showed 100% efficiency of both techniques to produce expansion in both groups. Mid-palatal, frontonasal, and intermaxillary sutures displaced and increased significantly (p ≤ 0.001) in width after treatment with both protocols, while the zygomaticomaxillary sutures compressed and showed a significant decrease in width with conventional MARPE, though, expanded and increased significantly in width with the ALT-RAMEC group (p < 0.001). The dentoskeletal effects revealed that conventional MARPE produced a buccal molar tipping while ALT-RAMEC showed a more bodily movement of the anchor molars. There were no additional effects of ALT-RAMEC on airway volume than MARPE did. Both protocols significantly increased the nasal cavity and oropharynx volumes and significantly decreased the nasopharynx and maxillary sinus volumes (p < 0.001) with a non-significant difference between groups (p > 0.05). The periodontium conditions were not correlated to the activation protocols in the current study, but the longer treatment time in the ALT-RAMEC group proved to have a more negative impact on the surrounding gingiva than conventional MARPE did. The modified ALT-RAMEC technique is a promising protocol sufficient to expand the maxilla transversely without tipping the anchored teeth in young adult patients.
Correlation between bone mineral density and vitamin d status among patients with type 2 diabetes mellitus in United Arab Emirates
(2025-03)
Allam, Hilda
Patients with type 2 diabetes (T2DM) may have a normal or high bone mineral density (BMD) with compromised bone structure. Inadequate vitamin D levels may reduce BMD and contribute to the development of diabetes. However, the results remain still controversial, and the underlying mechanism influencing BMD in T2DM are not fully understood. Factors such as age, sex, ethnicity, glycemic control, and vitamin D levels contribute to these variations. This study aimed to evaluate the BMD T score and correlate it with serum levels of vitamin D [25(OH)D], inflammatory, and bone markers in Emirati patients with T2DM. A cross-sectional study took place at the outpatient diabetic clinics of University Hospital Sharjah and Al Qassimi Hospital. A total of 128 Emirati individuals with T2DM aged 25 to 65 years were recruited (male: 46, female: 82). Participants underwent anthropometric measurements, and blood samples were collected to assess diabetic markers, bone and inflammatory markers, parathyroid hormone (PTH), calcium and vitamin D levels. Additionally, genetic polymorphisms in vitamin D receptor (VDR) and osteocalcin genes were analyzed for association with BMD and vitamin D. BMD was assessed using quantitative ultrasound scan (QUS) at the cancellous bone. According to QUS measurements, 69.5% of participants had low BMD, while 30.5% had normal BMD. Vitamin D levels were found to be low in 44.5% of participants, whereas 55.5% had optimal levels. BMD was significantly correlated with vitamin D levels (r= 0.297, p < 0.001), whereas bone markers did not significantly differ between normal and abnormal BMD groups The genetic analysis of VDR and osteocalcin gene polymorphisms showed no significant association with BMD or vitamin D levels. Poorly glycemic control (HbA1c ≥6.5) was observed in 83.6% of participants, while 16.4% had good glycemic control. Optimal vitamin D levels were associated with lower HbA1c (p = 0.030). Multivariate regression analysis revealed that vitamin D (β= 0.012, p <0.001) and sex (β= 0.393, p =0.017) had a significant positive association with BMD, whereas age showed a negative association with BMD (β= -0.033, p < 0.001). Logistic regression analysis further indicated that high insulin levels were linked with a better BMD score (OR=0.961; 95%CI: 0.925-0.999, p = 0.042), while high IL-6 levels were associated with low BMD scores (OR=1.289; 95%CI: 1.071-1.551, p = 0.007), suggesting that IL-6 is a strong predictor of BMD. In conclusion, BMD in T2DM is influenced by multiple factors, including vitamin D levels, age, sex, and inflammation. Given the high prevalence of low BMD, healthcare providers should monitor individuals at risk for fractures and consider intervention to improve health in patients with T2DM.
Cytotoxicity mechanism of gallic acid and methyl gallate combined with cisplatin on cervical cancer (HeLa) cells
(2025-08)
Mamat, Norlida
Cervical cancer is the fourth most common cause of cancer-related death affecting women worldwide. Cisplatin is one of the chemotherapy drugs used in the treatment of cervical cancer. However, cisplatin was reported to cause toxicity to normal cells and develop cell resistance with other side effects. Combining chemotherapy agents is one of the strategies to increase the effectiveness of anticancer drugs through synergistic effects. Gallic acid and methyl gallate are the most abundant phenolic compounds that have been reported to have good antioxidant and anticancer activities. Hence, in this study, gallic acid and methyl gallate were selected as combination substances with cisplatin. This study was conducted to elucidate the cytotoxicity mechanism of gallic acid and methyl gallate combined with cisplatin on cervical cancer (HeLa) cells through apoptosis mode of cell death. Furthermore, the antioxidant capacity of the cells treated with single and combination treatment was also evaluated. Cytotoxicity activity of gallic acid, methyl gallate and cisplatin on HeLa and NIH/ 3T3 cells was determined using MTT assay. The effects of gallic acid and methyl gallate combined with cisplatin were then determined using CompuSyn software. The morphology and percentage of apoptotic cells were evaluated using Hoechst staining and annexin V/PI assay. The expression of apoptotic and anti-apoptotic proteins (Bax, Bcl-2, caspase-3, caspase-9 and p53) was further determined by western blot analysis. The migration inhibitory effect of the combinations was also evaluated using scratch wound healing assay. The antioxidant activity of gallic acid and methyl gallate was measured using DPPH assay. Reactive oxygen species (ROS) and antioxidant enzyme activity were measured spectrophotometrically while the expression of antioxidant genes (SOD1 and hCAT) in HeLa-treated cells was then evaluated using RT-PCR. Gallic acid and methyl gallate showed strong cytotoxicity effects on HeLa cells. The IC50 values of gallic acid, methyl gallate and cisplatin on HeLa cells were 13.44 μg/mL, 16.55 μg/mL and 8.04 μg/mL whereas in NIH/3T3 cells were 32.90 μg/mL, 35.70 μg/mL and 6.57 μg/mL respectively. Gallic acid and methyl gallate in combination with cisplatin inhibited greater HeLa cell proliferation than cisplatin alone with synergistic effects seen in combination with cisplatin at concentrations of 0.51-4.02 μg/mL. Morphological observation of Hoechst staining then revealed the appearance of several apoptotic features in all treated cells. Consistently, flowcytometry analysis showed that the percentages of early apoptotic cells in the combination of cisplatin-gallic acid (28.72 ± 1.14) and cisplatin-methyl gallate (23.37 ± 9.72) groups were significantly higher than the control group (6.00 ± 0.95). The combination treatments significantly upregulated Bax, caspase-3, caspase-9 and p53 expressions and downregulated bcl-2 expressions as compared to the untreated group. Moreover, the treatments were shown to have migration-inhibitory effects after 24 hours. Gallic acid and methyl gallate exhibited strong antioxidant activity with EC50 values of 18.23 μM and 19.39 μM respectively. The combination treatments significantly increased intracellular ROS levels and reduced the level of SOD and catalase in an enzymatic assay. This result was consistent with RT-PCR result that showed the downregulation of SOD1 and hCAT genes in all treated samples. In conclusion, these findings suggest that the combination of gallic acid and methyl gallate with cisplatin synergistically inhibited proliferation by inducing apoptosis and ROS in cervical cancer cells
Demystifying the diagnostic potentials of air-conducted ocular and cervical vestibular evoked myogenic potential test elicited by a custom-built chirp stimulus among patients with vestibular disorders
(2024-06)
Abdallatif, Athar Mazen Rasmi
The vestibular evoked myogenic potential (VEMP) is a clinical method to assess the function of otolith organs. VEMP is typically recorded with the 500 Hz tone burst, however, a chirp stimulus, initially designed for auditory brainstem responses, is being used to explore VEMP's diagnostic potential. This study explores the diagnostic potential of an air conducted downward narrowband chirp stimulus in detecting vestibular disorders using cervical VEMP (cVEMP) and ocular VEMP (oVEMP). In the initial stage, two pilot studies involving 25 healthy adults for cVEMP (Pilot 1) and 35 healthy adults for oVEMP (Pilot 2) were conducted to identify the optimal chirp stimulus. The optimal stimulus from the pilot studies was then compared with the 500 Hz tone burst stimulus in cVEMP and oVEMP responses in the subsequent case control experiment. The cVEMP testing was conducted on 55 healthy adults with a mean age of 29.5 ± 9.1 years and 43 patients with vestibular disorders with a mean age of 41.6 ± 8.9 years. On the other hand, the oVEMP testing was performed on 60 healthy adults with a mean age of 28.0 ± 7.3 years and 28 patients with vestibular disorders with a mean age of 41.5 ± 8.5 years. The two pilot studies revealed that the (1000-100) Hz chirp stimulus produced significantly higher amplitudes and shorter latencies of P1 and N1 for both cVEMP and oVEMP compared to the (1000-500) Hz chirp stimulus (p < 0.05). The (1000-100) Hz chirp stimulus was chosen to be used in the subsequent study. Results revealed that the (1000-100) Hz chirp stimulus generated significantly shorter latencies and larger amplitudes than the 500 Hz tone burst stimulus in the cVEMP testing (p <0.05). Likewise, the chirp stimulus elicited significantly shorter P1 and N1 latencies compared to the 500 Hz tone burst in the oVEMP testing (p <0.05). Receiver operating characteristic (ROC) analysis demonstrated the superior performance of the chirp stimulus for identifying patients with vestibular disorders. The chirp stimulus revealed a higher area under the curve (AUC), sensitivity, and specificity for both cVEMP and oVEMP tests compared to the tone burst. For cVEMP, the chirp's sensitivity ranged from 60.8% to 88.2%, and specificity from 38.7% to 87.7%, exceeding those of the tone burst (sensitivity: 51.5% to 89.7%, specificity: 40.3% to 87.4%). Similarly, oVEMP chirp’s sensitivity and specificity were 71.4% to 100.0% and 32.0% to 95.2%, respectively, surpassing those of the tone burst with sensitivity ranged from 38.0% to 78.4%, and specificity ranged from 11.5% to 94.1%. In conclusion, compared to the conventional 500 Hz tone burst stimulus, the (1000-100) Hz chirp stimulus has better diagnostic abilities to identify patients with vestibular disorders. Due to its promising outcomes, this stimulus can be an alternative stimulus for recording cVEMP and oVEMP in clinical practice.
Determination of morphological features and elemental profiles on bullet holes for forensic firearm investigation
(2024-09)
Bominathan, Uma Rashmika
A comprehensive scene reconstruction of firearm-related case requires forensic investigators to examine the bullet holes left on various surfaces to confirm if it was produced by a projectile and to subsequently determine if it was made by a specific ammunition. Evolvement of the design and technology of ammunition could have also led to the variation in bullet hole, particularly from non-conventional ammunition. This study was aimed to characterise bullet impact holes caused by various .38 and 9 mm calibre ammunition through physical and chemical means. Morphological features on the six commonly encountered surfaces such as Perspex, Plywood, Formica Board, metal sheet (cabinet), gypsum dan metal sheet (car door) within a firing scene due to the impacts of projectiles were examined. Later, sample recovered from the inner circumferences of bullet holes were examined by inductively coupled plasma-mass spectrometry (ICP-MS) and atomic absorption spectrometry (AAS) to determine the elemental profiles and compared among the bullet holes caused by the eight different ammunition types, namely Winchester .38 SPL, CBC .38 SPL, SME .38 SPL, SME 9 mm, GECO 9 mm, Advance Rotation Extreme (ARX) 9 mm, Ruag Ammotech 9 mm, and Sellier & Bellot 9 × 19. Through physical examination, perfect circular holes were observed with orthogonal angle impact, except for bullet holes impacted by the projectiles from ARX and GECO with the production of flower-like petalling effect at the edge of crater. On the other hand, full metal jacket (FMJ) and jacketed deform projectile (JDP) tends to transfer their materials onto the inner circumference of bullet holes, forming metallic rings. Stubbing procedure was found effective in recovering trace residues from bullet holes. Through ICP-MS detection, lead was found to be the major composition in six types of projectiles, except in ARX and GECO where copper dominated the elemental composition. Antimony, arsenic, bismuth, iron, silver, tin, and zinc were detected as minor composition. However, from the samples recovered from bullet holes, only four elements, namely antimony, copper, lead, and zinc, were successfully detected. Decomposition by principal component analysis (PCA) formed six clusters in the score plots in which impact marks of similar elemental profiles tend to cluster closely. The developed PCA score-linear discriminant analysis (LDA) model had also achieved an overall correct classification up to 85.4% in predicting the projectiles that impact a surface. To conclude, a thorough physical examination and chemical analysis aided in distinguishing the bullet impact holes made by different ammunition. Such important information possesses great potential in forensic investigation, especially in shooting cases.
Developing, validating and evaluating the effectiveness of a blended learning for teaching clinical surgical nursing skills among nursing students at Xiangnan University in Chenzhou, China
(2025-02)
Afang, Li
Online teaching is a new teaching method, and there is not much research on teaching clinical nursing skills and even less on the online teaching of this aspect of nursing apprenticeships. This study aimed to develop, validate, and evaluate a surgical nursing apprenticeship online and offline blended teaching module using the Learning Pass mobile app. This quantitative study design was carried out in two phases. Phase I involved the development and validation of a surgical nursing apprenticeship online and offline blended teaching module using the Learning Pass mobile app. The researchers and teaching team developed a blended teaching module based on the syllabus and literature review. After that, the blended teaching module was validated by ten experts using the Delphi method. In Phase II, a randomized control trial was conducted among 166 nursing students at Xiangnan University in Chenzhou, China, to evaluate the effectiveness of the blended teaching module towards skill performance, self-directed learning ability, online academic emotions, and learning attitude. The intervention group utilized online and offline blended teaching methods using the Learning Pass mobile app, while the control group used traditional face-to-face teaching methods. SPSS 26.0 statistical software was used for data analysis. One-sample t-tests, independent t-tests, and chi-square tests were performed. As a result of Phase I, the online and offline blended teaching module for the surgical nursing apprenticeship was agreed upon with 100% experts through two rounds of the Delphi technique. Phase II results showed that after the intervention, there was a significant increase in self-directed learning ability in the intervention group compared to the control group (p = 0.019), with the mean score for the intervention group 78.89 (SD = 13.32) and the control group 74.48 (SD = 11.55). The skill scores also showed a significant increase in the intervention group compared to the control group (p < 0.001), with the mean score for the intervention group 91.81 (SD = 3.54) and the control group 89.65 (SD = 4.11). The intervention group's mean value of online academic emotions (Mean = 3.33) was higher than the theoretical mean (Mean = 3), and the difference was statistically significant (p < 0.001). Besides that, there were no significant differences in the students' learning attitudes. In conclusion, online and offline blended teaching method using the Learning Pass mobile app effectively improves nursing skills, self-directed learning ability, and online academic emotions among nursing students. In the future, multicenter studies are needed to validate the effectiveness of this mobile app for online teaching, as well as longitudinal studies to assess long-term outcomes.

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