Influence of Vehicle Traffic Emissions on Spatial Variation of Ozone and its Precursors in Air of Port Harcourt City, Nigeria

This study aimed at assessing the influence of vehicle traffic on spatial variation of ozone (O3) and its vehicular emission precursors in the air of Port Harcourt city. Sampling was carried out in ten (10) sites, eight (8) located within the high traffic density area (study sites) and two (2) located within the very low traffic density area (reference sites). The precursor pollutants measured were nitrogen dioxide (NO2), carbon monoxide (CO) and volatile organic compounds (VOCSs). Ozone and the precursor pollutants were measured in situ using AeroQUAL 500 series portable ambient air analyzer while traffic flow survey was achieved by direct counting. Measurements were carried out at morning, evening and off-peak traffic periods respectively. The mean concentrations of ozone and the precursor pollutants were significantly higher (p = 0.05) in the study sites than in the reference sites. Mean concentrations were higher at peak traffic periods than at off-peak traffic periods except for ozone that was higher at off-peak than at morning peak. There was significant correlation between traffic density and each of the pollutants including ozone. The spatial variability in concentration of pollutants was influenced by vehicular traffic. VOCs and NO2 levels were higher than the National Ambient Air Quality Standard (NAAQS) limit of 0.05 ppm and 0.04 – 0.06 ppm respectively, O3 concentration was below the standard limit (0.06 ppm) but was at the verge of exceeding. Traffic emission within the city was significant and could be mitigated through regular monitoring and control

Nano-enhanced Drug Delivery of Dacarbazine using Heteroatoms (B, N, P, S) doped Ag-Functionalized Silicene Nanomaterials: Insight from Density Functional Theory

Cancer remains a major global health concern, necessitating the development of novel and more effective treatment strategies. This research focused on exploring the potential of silicene as a nano-drug delivery platform. Silicene, a two-dimensional honeycomb structure, has garnered attention as an alternative to graphene, germanenes, and stanenes due to its comparative advantages in interfacing with micro or nano electronic devices. In this study, we investigated the co-doping of Ag-doped silicene with B, N, P, and S to evaluate their potential as adsorbents for delivering dacarbazine (DCB). Density functional theory (DFT) calculations at the ωB97XD/def2SVP level of theory were utilized to analyze their sensitivity, conductivity, stability, and reactivity. The geometry optimization results revealed that the introduction of B, N, P, and S as co-dopants significantly reduced the Ag52—Si30 bond in the Ag-functionalized silicene nano surface from 2.589 Å to a range of 2.241–2.074 Å. Likewise, a similar post-co-doping magnitude reduction effect was observed in the energy gaps, with the interactions ranging from 3.1186—3.7325 eV. Regarding adsorption characteristics, the Ead values indicated physisorption in the B, N, and P-co-doped interactions and chemisorption in the S-co-doped system, with values of 28.399, 147.445, 235.100, and -141.345 kcal/mol, respectively. After incorporating the basis set superposition error (BSSE) correction to the calculated adsorption energies, the adjusted values were obtained as follows: dcb_B@AgSi, dcb_P@AgSi, and dcb_N@AgSi exhibited 28.400, 135.103, and 147.446 kcal/mol, respectively. Meanwhile, dcb_S@AgSi displayed an adsorption energy of -142.344 kcal/mol. Furthermore, analyzing the results using QTAIM and NCI revealed the presence of non-covalent interactions, as well as partial and covalent interactions. This study sheds light on the promising therapeutic potential of B, N, P, and S co-doped Ag-functionalized silicene nano systems as efficient nano-drug delivery agents for dacarbazine (DCB). The insights gained from this research could pave the way for the development of advanced drug delivery systems with enhanced sensitivity and stability

Investigating the intermolecular interactions in the explicitly solvated complexes of lomustine with water and ethanol

Lomustine is an alkylating chemotherapy drug that is used to treat diverse types of cancer, including brain tumors, Hodgkin's lymphoma, and non-Hodgkin's lymphoma, which works by interfering with the DNA in cancer cells, preventing them from dividing and growing. As such the lipid bilayer of the cell and body fluids provides the environments in which lomustine (lmt) performs its biological function. Chemical reactions involving biological systems occur in the liquid phase, where accurate modeling of the reaction pathways considers the influence of the solvent used. Implicit solvation adequately accounts for these effects but falls short when evaluating solvent-solute interactions. This study aims to explore the structures, thermodynamics, reactivity, UV–vis spectroscopy, energy decomposition analysis, and the interaction energies of lmt with molecules of water and ethanol (n = 1, 2, and 3), using density functional theory (DFT) at the ωB97XD/6–311++G (d, p) level of theory. The thermodynamics results reveal that the polarity of water molecules significantly influences the interaction strength of the studied systems as the interaction observed between lmt with W1, Et1, and Et2 is feasible and spontaneous, compared to others. The stability of the different clusters depends on the intermolecular hydrogen bonds formed between the drug and the polar solvent as explicated by the H-bond interaction distance. Also, the interaction of lmt with each of the solvents causes a slight deformation in the geometry of the lmt, moreover, the reactivity descriptors predicted the interaction of lmt to increase with a corresponding increase in the addition of water molecules

The Human Affectome

Over the last decades, the interdisciplinary field of the affective sciences has seen proliferation rather than integration of theoretical perspectives. This is due to differences in metaphysical and mechanistic assumptions about human affective phenomena (what they are and how they work) which, shaped by academic motivations and values, have determined the affective constructs and operationalizations. An assumption on the purpose of affective phenomena can be used as a teleological principle to guide the construction of a common set of metaphysical and mechanistic assumptions—a framework for human affective research. In this capstone paper for the special issue “Towards an Integrated Understanding of the Human Affectome”, we gather the tiered purpose of human affective phenomena to synthesize assumptions that account for human affective phenomena collectively. This teleologically-grounded framework offers a principled agenda and launchpad for both organizing existing perspectives and generating new ones. Ultimately, we hope Human Affectome brings us a step closer to not only an integrated understanding of human affective phenomena, but an integrated field for affective research