Filter options

Publication Date
From
to
Subjects
Journals
Article Types
Countries / Territories
Open Access January 02, 2025

Ambient Air Quality and Human Health Risk Assessment of Heavy Metals in a Potentially Toxic Silver-Polluted Environment

Abstract Silver nanoparticles (Ag+NPs) contamination in the environment is a serious concern. This study investigated selected heavy metal (Ag+, Cd2+, Cr2+ and Pb2+) concentrations at different sampling points to assess the risk to human health (infants, children, and adults). To do this, an enclosed area (laboratory) of 12.6 m X 8.5 m (107.1 [...] Read more.
Silver nanoparticles (Ag+NPs) contamination in the environment is a serious concern. This study investigated selected heavy metal (Ag+, Cd2+, Cr2+ and Pb2+) concentrations at different sampling points to assess the risk to human health (infants, children, and adults). To do this, an enclosed area (laboratory) of 12.6 m X 8.5 m (107.1 m2) was clearly marked at different coded distances of S1, S2, S3, and S4 representing 2, 4, 6, and 8 m, while unpolluted atmosphere at 50 m away without Ag+NPs served as the control (S5). The silver fireworks were allowed to burn for an approximate 00h03m30s at each sampling points using a high-volume air sampler mounted at the Environmental Engineering Departmental Laboratory, Rivers State University, with windows and doors closed to simulate indoor conditions. Samples were digested using a mixture of analytical-grade nitric acid, analytical-grade hydrochloric acid and analyzed to evaluate the levels of heavy metals by atomic absorption spectrophotometry. The Ag+ result at S1 shows 30,000 µg/cm3, S2 was 29,000 µg/cm3, while S3 was 28000 µg/cm3 and then S4 was 13,000 µg/cm3. These results exceeded the permissible values of the United States National Ambient Air Concentration for rural, urban and industrial areas (0.0005, 0.004 and 0.6 µg/cm3, respectively). The result for the control (S5) (0.037 µg/cm3) was within the maximum allowable value. Results from other heavy metals such as Cd were 1000, 743, 401, 153, 0.001 µg/cm3, Cr was 5000, 4000, 3729, 2960, 0.002 µg/cm3, Pb was 0.048, 0.041, 0.035, 0.034 and 0.01, µg/cm3, respectively. However, higher values of Ag+, Cd, and Cr indicated a higher propensity for the metals to be toxic (bioavailable). In addition, the assessment of the potential health risk posed by these metals proved contaminated and harmful. Visitors recorded high values in exposure concentration (EC) and low values in average daily dose (ADD).
Figures
PreviousNext
Article
Open Access January 03, 2024

Inflammatory Bowel Disease associated with Intestinal Malrotation

Abstract Intestinal malrotation is an embryological abnormality modifying the classic anatomy of the small and large bowels, particularly the topographical one. Inflammatory bowel disease (IBD) is characterised by anatomical lesions with preferential intestinal tropism. These two conditions are rarely associated. They represent a real diagnostic and therapeutic challenge due to the overlap of non-specific [...] Read more.
Intestinal malrotation is an embryological abnormality modifying the classic anatomy of the small and large bowels, particularly the topographical one. Inflammatory bowel disease (IBD) is characterised by anatomical lesions with preferential intestinal tropism. These two conditions are rarely associated. They represent a real diagnostic and therapeutic challenge due to the overlap of non-specific symptoms and the complexity of the clinical management. We report the case of a young woman presenting with a flare-up of her IBD and a partial common mesentery syndrome. Clinicians should be aware of the potential pitfalls of the two entities to propose the adequate therapeutic strategy regarding the full understanding of the anatomy, notably when surgery is needed.
Figures
PreviousNext
Case Report
Open Access September 20, 2022

Drug-Receptor Interaction of Peptidic HIV-1 Protease: Polar Effect-II

Abstract Klopman described the chemical reaction of metal ions and base ions in term of softness, En and Em, respectively. By simple modification of known methods, Singh et al. made it applicable for neutral Lewis acids (transition metal salts) and bases (organic molecules) and also extended its application to biological systems for site selectivity [...] Read more.
Klopman described the chemical reaction of metal ions and base ions in term of softness, En and Em, respectively. By simple modification of known methods, Singh et al. made it applicable for neutral Lewis acids (transition metal salts) and bases (organic molecules) and also extended its application to biological systems for site selectivity and to explain reaction mechanism (markovnikov and anti-markovnikov rule), ligand-receptor interaction of testosterones, estrogens and tetrahydroimidazobenzodiazepinone. In this study effective atomic softness En(eff) and Em(eff), and their change ΔEnm have been used for site selectivity and polar interaction between 51 peptidic HIV-1 protease inhibitors and receptor amino acids. ΔEnm values derived from drug-receptor interaction show that when one moiety on receptor behaves as nucleophile (O of valine amino acid) at the same time maximum electrophilic site of the drug (C-atom of the maximum En(eff) value) orient itself to come close the respective site and make maximum interaction, while when another moiety on receptor behaves as electrophilic site (C of isoleucine amino acid), at the same time maximum nucleophilic site of the drug (O-atom of the maximum Em(eff) value) also orient itself to come close the respective site and make maximum interaction.
Figures
PreviousNext
Article
Open Access May 20, 2021

Bioconcentration Factor of Polychlorinated Biphenyls and Its Correlation with UV- and IR-Spectroscopic data: A DFT based Study

Abstract Polychlorinated biphenyls (PCBs) are important class of persist organic pollutants that were used as a component of paints especially in printings, as plastificator of plastics and insulating materials in transformers and capacitors, heat transfer fluids, additives in hydraulic fluids in vacuum and turbine pumps. There is always a need to establish reliable procedures for predicting the [...] Read more.
Polychlorinated biphenyls (PCBs) are important class of persist organic pollutants that were used as a component of paints especially in printings, as plastificator of plastics and insulating materials in transformers and capacitors, heat transfer fluids, additives in hydraulic fluids in vacuum and turbine pumps. There is always a need to establish reliable procedures for predicting the bioconcentration potential of chemicals from the knowledge of their molecular structure, or from readily measurable properties of the substance. Hence, correlation and prediction of biococentration factors (BCFs) based on λmax and vibration frequencies of various bonds viz υ(C-H) and υ(C=C) of biphenyl and its fifty-seven derivatives have been made. For the study, the molecular modeling and geometry optimization of the PCBs have been performed on workspace program of CAChe Pro 5.04 software of Fujitsu using DFT method. UV-visible spectra for each compound were created by electron transition between molecular orbitals as electromagnetic radiation in the visible and ultraviolet (UV-visible) region is absorbed by the molecule. The energies of excited electronic states were computed quantum mechanically. IR spectra of transitions for each compound were created by coordinated motions of the atoms as electromagnetic radiation in the infrared region is absorbed by the molecule. The force necessary to distort the molecule was computed quantum mechanically from its equilibrium geometry and thus frequency of vibrational transitions was predicted. Project Leader Program associated with CAChe has been used for multiple linear regression (MLR) analysis using above spectroscopic data as independent variables and BCFs of PCBs as dependent variables. The reliability of correlation and predicting ability of the MLR equations (models) are judged by R2, R2adj, se, q2L10O and F values. This study reflected clearly that UV and IR spectroscopic data can be used to predict BCFs of a large number of related compounds within limited time without any difficulty.
Figures
PreviousNext
Editorial Article

Query parameters

Keyword:  Atom

View options

Citations of

Views of

Downloads of