Siti Hamimah Sheikh Abdul Kadir

Siti Hamimah Sheikh Abdul Kadir


Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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29 October 2021 in Membranes
Verified
Journal Article
Open access
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HZHazirah Syahirah Zakria
Hazirah Syahirah Zakria
Mohd Hafiz Dzarfan OthmanMohd Hafiz Dzarfan Othman
Mohd Hafiz Dzarfan Othman
SKSiti Hamimah Sheikh Abdul Kadir
Siti Hamimah Sheikh Abdul Kadir
RKRoziana Kamaludin
Roziana Kamaludin
Asim JilaniAsim Jilani
Asim Jilani
Muhammad AyubMuhammad Ayub
Muhammad Ayub
Existing toxic solvents in the manufacturing of polymeric membranes have been raising concerns due to the risks of exposure to health and the environment. Furthermore, the lower tensile strength of the membrane renders these membranes unable to endure greater pressure during water treatment. To sustain a healthier ecosystem, fabrication of polyvinylidene fluoride (PVDF) hollow fiber membrane using a less toxic solvent, triethyl phosphate (TEP), with a lower molecular weight polyethylene glycol (PEG 400) (0–3 wt.%) additive were experimentally demonstrated via a phase inversion-based spinning technique at various air gap (10, 20 and 30 cm). Membrane with 2 wt.% of PEG 400 exhibited the desired ultrafiltration asymmetric morphology, while 3 wt.% PEG 400 resulting microfiltration. The surface roughness, porosity, and water flux performance increased as the loading of PEG 400 increased. The mechanical properties and contact angle of the fabricated membrane were influenced by the air gap where 20 cm indicate 2.91 MPa and 84.72°, respectively, leading to a stronger tensile and hydrophilicity surface. Lower toxicity TEP as a solvent helped in increasing the tensile properties of the membrane as well as producing an eco-friendly membrane towards creating a sustainable environment. The comprehensive investigation in this study may present a novel composition for the robust structure of polymeric hollow fiber membrane that is suitable in membrane technology.

21 February 2020 in Membranes
Verified
Journal Article
Open access
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RKRoziana Kamaludin
Roziana Kamaludin
Zatilfarihiah RasdiZatilfarihiah Rasdi
Zatilfarihiah Rasdi
Mohd Hafiz Dzarfan OthmanMohd Hafiz Dzarfan Othman
Mohd Hafiz Dzarfan Othman
SKSiti Hamimah Sheikh Abdul Kadir
Siti Hamimah Sheikh Abdul Kadir
NNNoor Shafina Mohd Nor
Noor Shafina Mohd Nor
Juhana JaafarJuhana Jaafar
Juhana Jaafar
The presence of bisphenol A (BPA) in various water sources has potentially led to numerous adverse effects in human such as increased in blood pressure and derangement in liver function. Thus, a reliable treatment for the removing BPA is highly required. This present work aimed to study the efficiency of visible light driven photocatalytic dual-layer hollow fiber (DLHF) membrane for the removal of BPA from water and further investigated its detrimental effects by using an in-vivo model. The prepared membranes were characterized for their morphology, particles distribution, surface roughness, crystallinity and light absorption spectra. The removal of 81.6% and 86.7% in BPA concentration was achieved for N-doped TiO2 DLHF after 360 min of visible and UV light irradiation, respectively. No significant changes for all three groups were observed in liver function test meanwhile the rats-exposed to untreated BPA water shows significance blood pressure increment contrary to rats-exposed to treated BPA water. Similarly, the normal morphology in both jejunum and ileum were altered in rats-exposed to untreated BPA water group. Altogether, the presence of N-doped TiO2 in DLHF are shown to significantly enhance the photocatalytic degradation activity under visible irradiation, which effectively mitigates the effect of BPA in an in-vivo model.

17 January 2019 in PeerJ Preprints
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Preprint
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SMSiti Munirah
Siti Munirah
SKSiti Hamimah Sheikh Abdul Kadir
Siti Hamimah Sheikh Abdul Kadir
SVSushil Kumar Vasudevan
Sushil Kumar Vasudevan
Anti-fibrotic properties of ranibizumab have been well documented. As an antagonist to Vascular Endothelial Growth Factor (VEGF), ranibizumab works by binding and neutralizes all active VEGF, thus limits the progressive cell growth and proliferation. Its application in ocular diseases has shown remarkable desired effects, however to date its anti-fibrotic mechanism is not well understood. In this study, we identified metabolic changes in ranibizumab-treated Human Tenos’s fibroblast (HTF). Cultured HTFs were treated for48 hours with 0.5 mg/ml of ranibizumab and 0.5 mg/ml control IgG antibody which serves as a negative control. Samples from each group were injected into Agilent 6520 Q-TOF Liquid Chromatography/ Mass Spectrometer (LC/MS) System to establish the metabolite expression in both ranibizumab treated cells and control group. Data obtained was analysed using Agilent Mass Hunter Qualitative Analysis software to identify the most regulated metabolite following ranibizumab treatment. At statistical analysis of p-value < 0.01 with the cut off value of two-fold change, 31 identified metabolites were found to be significantly up-regulated in ranibizumab-treated group, with 6 of the mostly up-regulated have insignificant role in fibroblast’s cell cycle and wound healing regulations Meanwhile, 121 identified metabolites were down-regulated with seven of the mostly down-regulated are significantly involved in cell cycle and proliferation. Our findings demonstrated that ranibizumab abrogates the tissue scarring process and wound healing formation by regulating the expression of metabolites associated with fibrotic activity. In particular, we found that vitamin Bs are important in maintaining normal folic acid cycle, nucleotide synthesis, homocysteine and spermidine metabolism. This study provides an insight of ranibizumab mechanism of actions on HTFs from the perspective of metabolomics.

17 January 2019
Verified
Dataset
Open access
PDF file
SMSiti Munirah
Siti Munirah
SKSiti Hamimah Sheikh Abdul Kadir
Siti Hamimah Sheikh Abdul Kadir
SVSushil Kumar Vasudevan
Sushil Kumar Vasudevan
Anti-fibrotic properties of ranibizumab have been well documented. As an antagonist to Vascular Endothelial Growth Factor (VEGF), ranibizumab works by binding and neutralizes all active VEGF, thus limits the progressive cell growth and proliferation. Its application in ocular diseases has shown remarkable desired effects, however to date its anti-fibrotic mechanism is not well understood. In this study, we identified metabolic changes in ranibizumab-treated Human Tenos’s fibroblast (HTF). Cultured HTFs were treated for48 hours with 0.5 mg/ml of ranibizumab and 0.5 mg/ml control IgG antibody which serves as a negative control. Samples from each group were injected into Agilent 6520 Q-TOF Liquid Chromatography/ Mass Spectrometer (LC/MS) System to establish the metabolite expression in both ranibizumab treated cells and control group. Data obtained was analysed using Agilent Mass Hunter Qualitative Analysis software to identify the most regulated metabolite following ranibizumab treatment. At statistical analysis of p-value < 0.01 with the cut off value of two-fold change, 31 identified metabolites were found to be significantly up-regulated in ranibizumab-treated group, with 6 of the mostly up-regulated have insignificant role in fibroblast’s cell cycle and wound healing regulations Meanwhile, 121 identified metabolites were down-regulated with seven of the mostly down-regulated are significantly involved in cell cycle and proliferation. Our findings demonstrated that ranibizumab abrogates the tissue scarring process and wound healing formation by regulating the expression of metabolites associated with fibrotic activity. In particular, we found that vitamin Bs are important in maintaining normal folic acid cycle, nucleotide synthesis, homocysteine and spermidine metabolism. This study provides an insight of ranibizumab mechanism of actions on HTFs from the perspective of metabolomics.

17 January 2019 in PeerJ Preprints
Verified
Preprint
Open access
PDF file
SMSiti Munirah
Siti Munirah
SKSiti Hamimah Sheikh Abdul Kadir
Siti Hamimah Sheikh Abdul Kadir
SVSushil Kumar Vasudevan
Sushil Kumar Vasudevan
Anti-fibrotic properties of ranibizumab have been well documented. As an antagonist to Vascular Endothelial Growth Factor (VEGF), ranibizumab works by binding and neutralizes all active VEGF, thus limits the progressive cell growth and proliferation. Its application in ocular diseases has shown remarkable desired effects, however to date its anti-fibrotic mechanism is not well understood. In this study, we identified metabolic changes in ranibizumab-treated Human Tenos’s fibroblast (HTF). Cultured HTFs were treated for48 hours with 0.5 mg/ml of ranibizumab and 0.5 mg/ml control IgG antibody which serves as a negative control. Samples from each group were injected into Agilent 6520 Q-TOF Liquid Chromatography/ Mass Spectrometer (LC/MS) System to establish the metabolite expression in both ranibizumab treated cells and control group. Data obtained was analysed using Agilent Mass Hunter Qualitative Analysis software to identify the most regulated metabolite following ranibizumab treatment. At statistical analysis of p-value < 0.01 with the cut off value of two-fold change, 31 identified metabolites were found to be significantly up-regulated in ranibizumab-treated group, with 6 of the mostly up-regulated have insignificant role in fibroblast’s cell cycle and wound healing regulations Meanwhile, 121 identified metabolites were down-regulated with seven of the mostly down-regulated are significantly involved in cell cycle and proliferation. Our findings demonstrated that ranibizumab abrogates the tissue scarring process and wound healing formation by regulating the expression of metabolites associated with fibrotic activity. In particular, we found that vitamin Bs are important in maintaining normal folic acid cycle, nucleotide synthesis, homocysteine and spermidine metabolism. This study provides an insight of ranibizumab mechanism of actions on HTFs from the perspective of metabolomics.

1 November 2019
Verified
Conference Paper
Open access
JKJesmine Khan
Jesmine Khan
SKSiti Hamimah Sheikh Abdul Kadir
Siti Hamimah Sheikh Abdul Kadir
WZWan Nor I'zzah Wan Wan Mohamad Zain
Wan Nor I'zzah Wan Wan Mohamad Zain
RKRoziana Kamaludin
Roziana Kamaludin
ZRZatilfarihah Rasdi
Zatilfarihah Rasdi
ARAmirah Abdul Rahman
Amirah Abdul Rahman
Bisphenol A (BPA) is an environmental pollutant. Human beings are exposed to BPA through food and water. Due to its prolonged contact with the intestinal tract (IT), it might have harmful effects on the IT particularly in pregnant women and the fetuses. Objective of this study was to investigate the effect of BPA on the morphology and tight junction protein expression of the small intestine of pregnant rats. Twelve Pregnant Sprague Dawley rats were divided into group 1 (control, n=6) and group 2 (BPA treated, n=6). Group 1 received tween 80 and group 2 received BPA (0.2mg/ml) in drinking water. There were no significant differences in the villus height, crypt depth and the number of goblet cells in the jejunum and ileum between the two groups. Intestinal tight junction protein (ITJP) claudin 2 expression was similar in both groups. ITJPs claudin 3 and 4 were expressed less intensely in the ileum of group 2 as compared to group 1. Chronic low dose BPA throughout pregnancy in rats did not affect the morphology of villi, crypt, goblet cells and ITJP claudin 2 but reduced the expression of claudin 3 and 4 in the ileum, which might compromise intestinal barrier.