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PPKBSM, Pusat Pengajian Kejuruteraan Bahan dan Sumber Mineral (2025) EBB236 - Materials Thermodynamic.
No full textPPKBSM, Pusat Pengajian Kejuruteraan Bahan dan Sumber Mineral (2025) EBB215 Semiconductor Materials SEM 2 SA 2024/2025.
No full text
Targeting monocarboxylate transporter 1 in statin-related anti-cancer effects on mda-mb-231 cell line: in vitro and in silico studies
No full textTriple-negative breast cancer (TNBC) is a challenging subtype of breast cancer due to its poor prognosis and limited targeted therapeutic options, necessitating the exploration of novel treatment strategies. This study investigates the anti-cancer effects of statins on the MDA-MB-231 cell line by targeting the functional inhibition of monocarboxylate transporter 1 (MCT1). Drug treatments with lipophilic statin (simvastatin, lactone form), hydrophilic statin (pravastatin, lactone form), AZD3965 (specific MCT1 inhibitor) and tamoxifen were tested through various assays; MTT assay was for IC50 determination, wound healing/scratch assay for cell migratory capacity assessment, and LDH activity assay for metabolic activity. In addition, molecular docking analysis was carried out to compare the binding affinities of simvastatin lactone versus simvastatin acid and simvastatin lactone versus pravastatin lactone to human MCT1. The drug treatment (24 hours) in the MDA-MB-231 cells revealed the following IC50 values: simvastatin (66.5 μM, 95% CI: 51.8 - 87.9 μM), AZD3965 (69.1 μM, 95% CI: 59.6 - 79.0 μM) and tamoxifen (28.8 μM, 95% CI: 26.1 - 32.4 μM). Compared to untreated cells, simvastatin significantly inhibited migratory capacity (P 0.05), highlighting its potential as an anticancer agent Molecular docking simulations revealed that simvastatin lactone (-7.1 kcal/mol) had stronger binding affinity to MCT1 than pravastatin lactone (-6.9 kcal/mol), reflecting that lipophilicity influences affinity to MCT1. However, simvastatin acid (-6.9 kcal/mol) showed lower binding affinity than simvastatin lactone, likely due to lower lipophilicity and permeability. Overall, these findings highlight the potential significance of simvastatin-targeting MCT1 in the development of novel therapeutic approaches for TNB
Cytotoxicity study on the combination of cisplatin and gallic acid on cervical cancer cells (hela)
No full textCervical cancer is the fourth most common cancer among women worldwide and remains a major health concern. Cisplatin, a chemotherapeutic agent, is often limited by severe side effects and the development of resistance. Combining cisplatin with natural compounds, such as gallic acid, may enhance therapeutic efficacy while reducing toxicity. This study aimed to evaluate the cytotoxic and anti-migratory effects of cisplatin combined with gallic acid on cervical cancer cells (HeLa). Cytotoxicity was assessed using the MTT assay the half-maximal inhibitory concentration (IC50). Serial dilution of cisplatin, starting from its IC50 was combined with a fixed concentration of gallic acid at its IC50. The combination effects were analyzed using CompuSyn software to assess potential synergy, additivity, or antagonism. The combination with the greatest synergistic effect was then chosen for wound healing assay, to examine the anti-migratory effects of the combination. The IC50 of cisplatin and gallic acid for HeLa cells were 25.12 μg/mL and 85.70 μg/mL, after 24 hours, which decreased to 1.786 μg/mL and 13.27 μg/mL at 48 hours. For WRL-68 cells, the IC50 values of cisplatin and gallic acid were 28.02 μg/mL and >100 μg/mL at 24 hours, decreasing to 8.842 μg/mL and 21.06 μg/mL at 48 hours. All combinations of cisplatin and gallic acid significantly inhibited HeLa cell proliferation with combination index values below 1, indicating a synergistic effect. Furthermore, the combination exhibited anti-migratory effects, showing the lowest percentage of wound closure compared to control and single treatment groups. These findings suggest that combining cisplatin with gallic acid holds potential as a novel therapeutic strategy to enhance cervical cancer treatment outcome
The effect of 660nm light-emitting diode irradiation on human gingival fibroblast cell proliferation
No full textLight therapy has become a common treatment modality in various medical fields,
including dermatology, dentistry, and cosmetics. This study aimed to evaluate the effect
of 660 nm ligh-emitting diode on the proliferation and viability of human gingival
fibroblasts in vitro. The cells were irradiated with 660nm light-emitting diode for 60 and
120 seconds 24-hours post-seeding. After 24- and 48-hours irradiation, cell count, and
viability were determined. The results then were analysed using a one-way ANOVA test
(p < 0.05). The findings revealed a significant increase in cell proliferation rate and
viability in the irradiated groups compared to the control group, with the 120 seconds
irradiation group showing the highest enhancement at both time points. These results
suggest that 660 nm LED light can effectively promote the proliferation and viability of
human gingival fibroblasts, highlighting its potential as a valuable tool in regenerative
dentistry and periodontal therap
Anticancer effects of apis cerana and heterotrigona itama honeys on temozolomide-resistant glioblastoma cells
No full textGlioblastoma is characterized by high aggressiveness and poor prognosis with median survival rate of less than 15 months. Due to the complexity of surgery to remove whole tumour and rapid development of chemoresistance towards temozolomide (TMZ), apitherapy using honey emerges as potential alternative treatment for glioblastoma due to its rich phenolic compounds with high antioxidant properties. However, the difference between Apis cerana honey and Heterotrigona itama honey for anti-glioblastoma effects has not been extensively studied. In this study, the phytochemical composition of A. cerana and H. itama honey were compared using phytochemical screening test and fourier transform infrared spectroscopy (FTIR) analysis. Their antioxidant capabilities were also compared using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay. Then, the half-maximal inhibitory concentration (IC50) values of both honeys on TMZ-resistant glioblastoma cell line (DBTRG-05MG cells) were determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, while the analysis of cancer invasiveness and recurrence were determined through scratch assay and clonogenic assay respectively. After that, gene expressions between both honey-treated DBTRG-05MG cells were compared using quantitative reverse transcription polymerase chain reaction (qRT-PCR) to elucidate their effects towards apoptosis (MDM2 gene), metastasis (WNT5A gene) and chemoresistance (YTHDF2 gene). The analysis revealed that A. cerana honey contained higher levels of alkaloid and saponin as compared to H. itama honey, which contributed to its higher antioxidant activity as evidenced via the DPPH assay. This data was also supported by its lower IC50 value (130.5 ± 33.1 mg/mL) than H. itama honey (185.8 ± 27.6 mg/mL) in 72-hour treatment on DBTRG-05MG cells. In contrast, H. itama honey contained higher levels of flavonoid than A. cerana honey. Both honeys shared similar functional groups as indicated in FTIR analysis. A. cerana honey exerted strong inhibitory effect towards invasiveness and migration of DBTRG-05MG cells with its lowest closure percentage up to 72 hours while H. itama honey exerted strong prophylactic effect towards recurrence of DBTRG-05MG cells with its lowest colony number formed. However, there was no significant difference in MDM2, WNT5A and YTHDF2 expressions between honey-treated DBTRG-05MG cells. These findings suggest that A. cerana honey could be more effective in killing TMZ-resistant glioblastoma cells while H. itama honey could be more effective in preventing glioblastoma recurrence. The anticancer effect of each phytochemical in both honeys should be further investigated in future for better elucidation towards apoptotic, metastasis and chemoresistance mechanism
Optimizations of Q. Clear image reconstruction method for brain 18F PET/CT studies
No full textBrain ¹⁸F-FDG PET/CT is a crucial tool in assessing cerebral metabolism and diagnosing neurological conditions. However, dynamic acquisitions with short frame durations suffer from low count statistics and high noise levels, posing challenges for both image quality and quantification. The Q. Clear (BSREM) reconstruction algorithm introduces a β penalization parameter to improve image clarity, yet the optimal β setting for each frame duration remains unclear.
Methods: A phantom study was conducted using a Hoffman 3D brain phantom filled with 185 MBq of ¹⁸F-FDG. List-mode PET data were acquired and divided into five frame durations: 10 s, 30 s, 2 min, 5 min, and 30 min. Images were reconstructed using Q. Clear with 20 β values (ranging from 50 to 1000). Image quality was assessed using recovery coefficient (RC%) and signal-to-noise ratio (SNR). A Bayesian optimization framework was applied to identify the optimal β under three prioritization strategies: RC%-priority, SNR-priority, and balanced.
Results and Conclusion: High β values (≥950) were optimal for 10 s and 30 s frames to suppress severe noise, while mid-range values (β ≈ 650) achieved the best trade-off between anatomical clarity and quantitative stability for 2–30 min frames. Based on both visual interpretability and quantitative performance, β = 650 is recommended as a general-purpose reconstruction setting for Q. Clear in dynamic brain PET imaging, with potential for implementation in future adaptive protocols
Comparison among Butterworth, hann and gaussian filter in accurate activity quantification of m99 tc SPECT/CT imaging
No full textThis study focuses on evaluating the accuracy of activity quantification in 99mTc Single Photon Emission Computed Tomography/Computed Tomography (SPECT/CT) imaging achieved through three different filters which is Butterworth, Gaussian and Hann filters with different parameters. The primary objective is to determine the optimal filter with optimal parameter for accurate quantification of 99mTc activity in SPECT/CT imaging. Quantitative imaging with 99mTc SPECT/CT faces challenges such as noise, resolution limitations and partial volume effects. Therefore, filters are applied to improve resolution and reduce noise for better diagnostic accuracy. The study utilizes NEMA 2007/IEC 2008 phantoms filled with 99mTc, using the GE Discovery NM/CT 670 Pro SPECT/CT system and tumor-to-background ratios (TBR) of 5:1 and 10:1. The experiment involved scanning with three filter parameters and performing a thorough comparison of the results using the recovery coefficient (RC) to evaluate filter performance across different sphere sizes. The sensitivity calibration was performed first using an activity concentration (AC) of 30 kBq/ml to establish the calibration factor (CF) for 99mTc SPECT activity quantification which is a crucial step in ensuring the accuracy of the diagnostic results. Then, image reconstruction and quantification were carried out using QMetrix software and the Xeleris workstation to facilitate detailed analysis. Based on the findings, Butterworth filter with a cut-off frequency (COF) of 0.5 provided the most optimal performance across various spherical diameters and yielded the smallest average quantification error when applied with Partial Volume Correction (PVC)
Assessment of absorbed dose to the eye's lens during dental cbct with different acquisition protocols
No full textDental cone-beam computed tomography (CBCT) is widely recognised as a valuable imaging modality in modern dentistry, offering high-resolution, three-dimensional images with relatively lower radiation exposure compared to conventional CT. Despite its advantages, CBCT still poses radiation risks to radiosensitive organs, particularly the eye lens, which has been linked to an increased risk of radiation-induced cataracts. This study was conducted to evaluate the absorbed dose to the eye lens during dental CBCT procedures using TLD-100 thermoluminescent dosimeters (TLDs), and to examine how variations in scanning parameters influence dose levels. A 3D anthropomorphic head phantom was employed to replicate a human, with TLDs was positioned at the specific locations of both eye lenses. The phantom was scanned using different CBCT exposure protocols, varying in field of view (FOV), tube voltage (kVp), and tube current (mA). The results demonstrated that absorbed dose to the eye lens was influenced by both FOV and mA settings. At a fixed FOV (medium size) and 8 mA, an increase in kVp from 60 to 90 resulted in increased eye lens dose from 0.778 mGy to 1.563 mGy. Conversely, when mA was varied from 3.2 to 16 mA at 60 kVp, the dose ranged from 0.420 mGy to 4.412 mGy. Additionally, under a constant 90 kVp setting, increasing FOV from XS to XL produced mean eye lens doses ranging from 2.148 mGy to 3.093 mGy. The use of TLD-100 dosimeters proved reliable in dose measurement, reinforcing the importance of accurate dosimetry for patient protection. This study underscores the need for optimised scanning protocols and consideration of energy correction factors to reduce unnecessary radiation exposure. Implementing dose-reduction strategies and increasing awareness among dental professionals can ensuring patients safety, particularly in procedures requiring repeated imaging