Utilization of natural dyes from Zingiber officinale leaves and Clitoria ternatea flowers to prepare new photosensitisers for dye-sensitised solar cells

Chlorophyll and ternatin were extracted from Zingiber officinale leaves and Clitoria ternatea flowers respectively. These natural dyes were applied as sensitisers in TiO2-based dye-sensitised solar cells (DSSCs). Among 10 different solvents, the ethanol extracts revealed the highest absorption spectra of natural dyes extracted from Z. officinale and C. ternatea. A major effect of temperature increase was the increased extraction yield. High chlorophyll and ternatin yields were obtained under extraction temperatures of 80 °C and 70 °C, respectively. A notable decrease in C. ternatea dye concentration at temperatures >70 °C was also observed. High dye concentrations were obtained using acidic extraction solutions, particularly those with a pH value of 4. Experimental results showed that the DSSC fabricated with chlorophyll extracted from Z. officinale leaves exhibited a conversion efficiency of 0.30%, open-circuit voltage (Voc) of 0.56 V, short-circuit current (Isc) of 0.8 mA/cm−2 and fill factor (FF) of 57.93%. The DSSC sensitized with ternatin from C. ternatea flowers displayed a conversion efficiency of 0.13%, Voc of 0.54 V, Isc of 0.3 mA/cm−2 and FF of 81.82%

Seasonal distribution of organic carbon in the surface sediments of the Terengganu nearshore coastal area

Terengganu water experienced the semi annual reversal in the wind system and the reversal in the current flow, in the upper layer of the ocean. Due to this reason, a north east monsoon season and a south east monsoon season, can be clearly distinguished in the South China Sea. Their coastal near shore areas are active sites where huge amount of organic matter is introduced into the ocean system through river runoff, in situ primary production and anthropogenic impacts. Interaction between a complex mixture of organics and inorganic enhances active material cycling's in time and space. However, different factors may control the partitioning and also the bioavailability of the hydrophobic organic compound pollutants within the benthic ecosystem. These factors include various sediment characteristics, such as grain size distribution, mineral composition and organic content (1), (2), (3). Surface sediments may be resuspended and redistributed by the action of waves and currents (4), (5). As these phenomena erode the top most layers of the sediment column, resuspended sediments contain recently deposited organic matter. In shallow water bodies of about a few meters deep, this matter may be rich in easily degradable fractions, as debris from dead marine organisms may rapidly settle onto the sediment surface. Therefore, through the processes of sediment resuspension and redistribution, organic matter at the sediment-water interface may be a significant source of easily remineralizable materials

Antimicrobial activities of graphene oxide against biofilm and intracellular Staphylococcus aureus isolated from bovine mastitis

Abstract Background S. aureus is one of the causative agents of bovine mastitis. The treatment using conventional antimicrobials has been hampered due to the development of antimicrobial resistance and the ability of the bacteria to form biofilms and localize inside the host cells. Objectives Here, the efficacy of graphene oxide (GO), a carbon-based nanomaterial, was tested against the biofilms and intracellular S. aureus invitro. Following that, the mechanism for the intracellular antimicrobial activities and GO toxicities was elucidated. Methods GO antibiofilm properties were evaluated based on the disruption of biofilm structure, and the intracellular antimicrobial activities were determined by the survival of S. aureus in infected bovine mammary cells following GO exposure. The mechanism for GO intracellular antimicrobial activities was investigated using endocytosis inhibitors. GO toxicity towards the host cells was assessed using a resazurin assay. Results At 100 ug/mL, GO reduced between 30 and 70% of S. aureus biofilm mass, suggesting GO’s ability to disrupt the biofilm structure. At 200 ug/mL, GO killed almost 80% of intracellular S. aureus, and the antimicrobial activities were inhibited when cells were pre-treated with cytochalasin D, suggesting GO intracellular antimicrobial activities were dependent on the actin-polymerization of the cell membrane. At < 250 ug/mL, GO enhanced the viability of the Mac-T cell, and cells were only affected at higher dosages. Conclusion The in vitro efficacy of GO against S. aureus in vitro suggested the compound could be further tested in Vivo to zrecognize its potential as one of the components of bovine mastitis therapy

Abstracts of the International Halal Science Conference 2023

This book presents the extended abstracts of the selected contributions to the International Halal Science Conference, held on 22-23 August 2023 by the International Institute for Halal Research and Training (INHART), IIUM, Malaysia in collaboration with Halalan Thayyiban Research Centre, University Islam Sultan Sharif (UNISSA), Brunei Darussalam. With the increasing global interest in halal products and services, this conference is timely. Conference Title:  International Halal Science ConferenceConference Acronym: IHASC23Conference Theme: Halal Industry Sustainability Through ScienceConference Date: 22-23 August 2023Conference Venue: International Islamic University (IIUM), MalaysiaConference Organizer: International Institute for Halal Research and Training (INHART), International Islamic University (IIUM), Malaysi