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Understanding the atomic behaviour of pure graphene is crucial in manipulating its properties for achieving optoelectronics with high absorption indexes and efficiencies. However, previous research employing the DFT approach emphasised its zero-band gap nature, not its unique optical properties. Therefore, this study employed ab initio calculations to revisit the electronic, magnetic, and optical properties of pristine graphene using the WIEN2K code. The results reveal that the PBE-GGA valence and conduction bands cross at -0.7 eV. Our calculations demonstrated that the absorption coefficient of graphene has the strongest light penetration in the parallel direction. Furthermore, our results not only present the best possible propagation of light in pure graphene but also reveal that the linear relationship between the formation of the free electron carriers and the energy absorption is responsible for the high optical conductivity observed in pure graphene, as indicated by the peaks. Lastly, the metallic properties of graphene are reflected by the variation in spin up and down that appears, as evidenced by the total and partial densities of states, and the large refractive index attributed to its high electron mobility confirms its metallic nature. [ABSTRACT FROM AUTHOR]

This study focuses on investigating the dynamic adsorption of Rhodamine B (RhB) from reduced graphene oxide (rGO) derived from oil palm waste. The synthesis of rGO from palm kernel shell (PKS) was achieved through double oxidation and carbonization method, resulting in a yield of 73.5 wt%. The reduction of oxygen-containing functionalities process using PKS was confirmed by FTIR spectroscopy, microscopic evaluation, and Xray diffraction analyses. Laboratory-scale fixed-bed experiments were conducted with various process parameters. Both PKS and rGO were used as adsorbents, and a comparison was made based on breakthrough curve analysis, adsorption capacity and percentage removal of dye. The adsorption kinetics of RhB on PKS and rGO were best described by the non-linear Yoon-Nelson model, with a high adsorption capacity of 88.32 mg/g and 195.24 mg/g respectively. Using both PKS and rGO, the maximum adsorption capacity was observed when using 10 cm bed depth column, inlet dye concentration of 5 mg/L, flow rate of 12 mL/min and pH of 7. PKS exhibited good dye removal with an efficiency of 66.54%. Meanwhile, the exothermic behavior highlighted the potential of utilizing rGO for maximum dye removal, achieving an efficiency of 90.35%. This study justifies rGO as a costeffective superior dye removal adsorbent, providing new prospect for large-scale dye removal. [ABSTRACT FROM AUTHOR]

Biomarkers are biological molecules associated with physiological changes of the body and aids in the detecting the onset of disease in patients. There is an urgent need for self-monitoring and early detection of cardiovascular and other health complications. Several blood-based biomarkers have been well established in diagnosis and monitoring the onset of diseases. However, the detection level of biomarkers in bed-side analysis is difficult and complications arise due to the endothelial dysfunction. Currently single volatile organic compounds (VOCs) based sensors are available for the detection of human diseases and no dedicated nanosensor is available for the elderly. Moreover, accuracy of the sensors based on a single analyte is limited. Hence, breath analysis has received enormous attention in healthcare due to its relatively inexpensive, rapid, and noninvasive methods for detecting diseases. This review gives a detailed analysis of how biomarker imprinted nanosensor can be used as a noninvasive method for detecting VOC to health issues early using exhaled breath analysis. [ABSTRACT FROM AUTHOR]

Black cumin seed oil has been traditionally used as Karumjeerakam kuzhi thailam (Siddha formulation) in India more than 500 years ago. This study was conducted to find out the bioactive molecules present in black cumin seed oil. The oil was subjected to gas chromatography-mass spectrometry (GC–MS) and liquid chromatography-mass spectrometry (LC–MS) techniques, and the obtained results were compared with the National Institute of Standard Library to identify the presence of chemical compounds. Based on GC–MS and LC–MS analyses, several bioactive compounds were detected such as octanoic acid (m/z 144.21), benzene, 1,3-bis (1,1-dimethyl ethyl) (m/z 190.32), maculosin (m/z 260.1), capric acid (m/z 172.26), 3-ketosphingoshine (m/z 297.3), hygrine (m/z 141.1), tetradecanoic acid, ethyl ester (m/z 256.42), and 2-monomyristin (m/z 302.4). Moreover, the oil was further evaluated for its anti-bacterial activity against both Gram-positive and Gram-negative bacteria and was found that it inhibited the growth of Staphylococcus aureus and Pseudomonas aeruginosa at a concentration of 10 µg/mL. Besides, molecular docking with capric and caprylic acid from the oil has shown a stable binding affinity with major quorum-sensing proteins. Laetisaric acid showed the best binding scores among the 11 compounds selected for the study with the corresponding receptors. These interactions could provide more insight into understanding the action of the identified compounds on various targets. [ABSTRACT FROM AUTHOR]

Lead has been the major source of environmental pollution today. The removal of this pollutant has been a topic of significant importance among the scientific community. Therefore, to emphasise the quantity and specific removal of lead ion through the reactivity of lead toward NAAM was the objective of this study, and to analyse mechanisms involved in absorption and adsorption of lead. Thus, the study reports preparation of activated alumina based on green in house coupled with design of experiment (DOE) based on response surface methodology six parameters that were found significant in determining the quality NAAM produced (pH, NaOH, H2SO4, DI (H2O), and Al). The trend showed that a higher amount of aluminium, the micro-pore volume, and the adsorption cumulative volume of the pores for the activated alumina were 0.000821 cm3/g, 0.00221 cm3/g, and 0.002203 cm3/g. The produced NAAM have been tested for their potential to remove lead ion Pb2+ from wastewater, and the results have been promising. Adsorbent temperatures, dose, concentrations, contact time, and temperature have all been observed to affect the adsorption of Pb2+ onto membranes in laboratory experiments. The investigations were conducted at varying pH of the natural solution. The Langmuir and Freundlich models for the equilibrium data was well-fitting, with the maximum adsorption capacity of 25 mg of lead/g of the nanomembrane. The two model was further supported by the pseudo-second-order model introduced. The results of the experimental data revealed that the maximum removal rate for lead ion was 100% when the conditions were perfect. During the first 5 min, the sorption of lead ion on the membrane was rapid, and equilibrium was achieved in less than 20 min and confirmed by the Langmuir and Freundlich models and as well as the pseudo-second-order model where the kinetic of the lead on adsorption obeyed with the model. Thus, when it came to the removal of lead ion from aqueous solution, the membrane tested in this study shows excellent potential. [ABSTRACT FROM AUTHOR]

Rice tends to accumulate heavy metals present in soil that have been introduced by human activities and pass them up the food chain. The present study aimed to evaluate the accumulation of selected trace elements (Cu, Zn, and Pb) in paddy and soil and the transfer of these metals from soil to rice by analysing the bioconcentration factor (BCF), bioaccumulation factor (BAF), and translocation factor (TF) of heavy metals in paddy (Oryza sativa L.) and soil. Samples of matured paddy and the substrates were collected from three different areas located near a rural point (RP), a transportation point (TP), and an industrial point (IP). Heavy metal concentrations present in the soil and various parts of the plants were ascertained using an atomic absorption spectrophotometer (AAS). Cu, Zn, and Pb accumulation in the soil were detected in increasing orders of RP > TP > IP, IP > TP > RP, and IP > RP > TP, respectively. The BCFshoot, BAF, and transfer factor of both Zn and Pb from soil to rice were detected in the order of TP > IP > RP, which was different from Cu, where BCFshoot and TF showed the order of RP > IP > TP but the BAF indicated IP > RP > TP. TF > 1 was discovered for Zn and Pb at the TP, and for Cu at the RP, which could be attributed to the TP's strongly acidic soil and Cu's abundance in the RP's soil. Paddy height and yield traits were the most significant at the IP site, showing the highest number of fertile spikelets, the average weight of a 1000-paddy spikelet, and the harvest index (0.56). These findings can be related to the normal range of Zn and Pb found in rice plants that support growth. Thus, the findings of this study demonstrated that soil properties and metal abundance in soil from certain land use practices can partially influence the mobility and transfer of metals through soil–plant pathways. [ABSTRACT FROM AUTHOR]