The Karnaphuli River estuary, located in southeast coast of Bangladesh, is largely exposed to heavy metal contamination as it receives a huge amount of untreated industrial effluents from the ...Chottagram City. This study aimed to assess the concentrations of five heavy metals (As, Pb, Cd, Cr and Cu) and their bioaccumulation status in six commercially important fishes, and also to evaluate the potential human health risk for local consumers. The hierarchy of the measured concentration level (mg/kg) of the metals was as follows: Pb (13.88) > Cu (12.10) > As (4.89) > Cr (3.36) > Cd (0.39). The Fulton's condition factor denoted that fishes were in better 'condition' and most of the species were in positive allometric growth. The bioaccumulation factors (BAFs) of the contaminants observed in the species were in the following orders: Cu (1971.42) > As (1042.93) > Pb (913.66) > Cr (864.99) > Cd (252.03), and among the specimens, demersal fish, Apocryptes bato appeared to be the most bioaccumulative organism. Estimated daily intake (EDI), target hazard quotient (THQ), hazard index (HI) and carcinogenic risk (CR) assessed for potential human health risk implications suggest that the values were within the acceptable threshold for both adults and children. However, calculated CR values indicated that both age groups were not far from the risk, and HI values demonstrated that children were nearly 6 times more susceptible to non-carcinogenic and carcinogenic health effects than adults.
Heavy metal pollution in sediment resources may pose serious threat to ecosystem and human health through food web. In this study, surface sediment samples of 10 stations along the Feni River estuary ...were analyzed to profile the accumulation, sources and pollution levels of heavy metals. The results revealed that the average contents (μg g−1) of eight selected heavy metals followed the order of Mn (37.85) > Cr (35.28) > Ni (33.27) > Co (31.02) > Pb (6.47) > Ag (1.09) > As (0.85) > Hg (0.71), and the concentrations varied spatially and seasonally with relatively higher levels at upward stations and during the rainy season. According to sediment quality guidelines (SQGs), the sediment samples were heavily contaminated with Ag and Hg, and moderately with Co. Threshold effect concentration (TEC) and probable effect concentration (PEC) values indicated that the concentration of only Ni and Cr were likely to occasionally exhibit adverse effects on the ecosystem. Enrichment factor (EF), geo-accumulation index (Igeo) and contamination factor (CF) analyses revealed that Ag, Co and Hg were at moderate to high pollution levels and the rests (As, Cr, Ni, Pb and Mn) were at no to low pollution levels. Potential ecological risk index (PERI) also showed that Ag, Co and Hg were the most potential ecological risk factor being determined in this studied area. Correlation matrix combined with multivariate principal component analysis and cluster analysis suggest that Ag, Co, Ni and Hg originated from anthropogenic sources (agrochemicals, silver nanoparticles anti-microbial agent, silver plating), whereas As, Cr, Pb and Mn primarily originated from natural geological background.
•EF, Igeo, CF and PERI were used to profile pollution levels of heavy metals in sediments of the Feni River estuary.•Ag, Co, Hg and Ni enrichment was more in sediments.•Ag and Co were above average shale values; however, Ni exceeded the TEC values.•Ag, Co and Ni threats to aquatic ecosystem should not be ignored.
There is a demand to develop techniques for the continuous removal/immobilization of heavy metals from contaminated soil and water bodies. In this study, a unique biochar preparation method was ...developed for the removal of cadmium. First, conventional biochars of corn straw were produced by pyrolysis at two temperatures and then treated using one-step synthesis at different ferric nitrate ratios and different calcination temperatures to produce magnetic biochars. Second, the prepared biochars were used as adsorbents for Cd(II) removal from a solution, and the best one was selected for further evaluation. Various techniques were used to characterize the adsorbents and determine the main adsorption mechanism. The results indicated that the biochars successfully carried iron particles within, which improved the specific surface area, formed inner-sphere complexes with oxygen-containing groups, and increased the number of oxygen-containing groups. The adsorption experiments revealed that MBC800-0.6300 had a higher affinity for Cd(II) than the other adsorbents. Batch adsorption experiments were performed to explore the influence of the kinetics, isotherm, pH, thermodynamics, ionic strength, and humic acid on Cd(II) adsorption. The results indicated that the Langmuir model fit the Cd(II) adsorption best with MBC800-0.6300 having the highest adsorption capacity (46.90 mg g−1). The sorption kinetics of Cd(II) on the adsorbent follows a pseudo-second-order kinetics model. Because MBC800-0.6300 is loaded with metal ions, it can be conveniently collected by a magnet. Thus, biochar modification methods with ferric nitrate impregnation provide an excellent approach to eliminating Cd(II) from aqueous solutions. The possible adsorption mechanisms include chemisorption, electrostatic interaction, and monolayer adsorption.
•Magnetic biochars were produced by using a one-step synthesis.•The maximum adsorption capacity of MBC800-0.6300 for Cd(II) is 46.9 mg g−1.•The Langmuir model is a good fit for adsorption process of Cd(II) to define monolayer sorption.•The Cd(II) -loaded MBC800-0.6300 can be conveniently collected by a magnet.
A national-scale inventory of heavy metal inputs is essential to understand the current situation of contribution and spatial heterogeneity of heavy metal sources in China. Published literatures from ...2008 to 2018 about heavy metal inputs from various pollution sources (atmospheric deposition, livestock manures, fertilizers, and sewage irrigation) to agricultural soils were collected. In the past ten years, atmospheric deposition was the main pollution source which was responsible for 50–93% of the total As, Cd, Cr, Hg, Ni, and Pb inputs, with livestock manures contributed to approximately 76% of total Cu inputs. However, due to industrial structure, geographical condition and the characteristics of economic development, the contribution of different sources to heavy metal pollution varies in different regions. For example, atmospheric deposition was the most important contributor in North China with its highly developed heavy industry and more coal combustion, while the contribution of livestock manures was obviously higher in South China due to its flourishing agricultural production and animal husbandry. Based on the analysis for clarifying the major pollution sources of five typical heavy metals (namely Cd, As, Hg, Cu and Pb), the controlling measures are suggested to make more effective and targeted strategies to protect agricultural soils in the future.
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•Atmospheric deposition (AD) contributed 50–93% for As, Cd, Cr, Hg, Ni and Pb inputs in farmlands in China.•Livestock manures (LM) was the most contributor for Cu, up to 76%.•AD exhibited higher contribution proportion in NC than in SC, while opposite tendency presented in LM.•Targeted heavy metal control measures were given based on the spatial heterogeneity in China.
A detailed understanding of the molecular mechanism of SARS-CoV-2 pathogenesis is still elusive, and there is a need to address its deadly nature and to design effective therapeutics. Here, we ...present a study that elucidates the interplay between the SARS-CoV and SARS-CoV-2 viruses' and host's miRNAs, an epigenetic regulator, as a mode of pathogenesis; and we explored how the SARS-CoV and SARS-CoV-2 infections differ in terms of their miRNA-mediated interactions with the host and the implications this has in terms of disease complexity. We have utilized computational approaches to predict potential host and viral miRNAs and their possible roles in different important functional pathways. We have identified several putative host antiviral miRNAs that can target the SARS viruses and also predicted SARS viruses-encoded miRNAs targeting host genes.
In silico
predicted targets were also integrated with SARS-infected human cell microarray and RNA-seq gene expression data. A comparison between the host miRNA binding profiles on 67 different SARS-CoV-2 genomes from 24 different countries with respective country's normalized death count surprisingly uncovered some miRNA clusters, which are associated with increased death rates. We have found that induced cellular miRNAs can be both a boon and a bane to the host immunity, as they have possible roles in neutralizing the viral threat; conversely, they can also function as proviral factors. On the other hand, from over representation analysis, our study revealed that although both SARS-CoV and SARS-CoV-2 viral miRNAs could target broad immune-signaling pathways; only some of the SARS-CoV-2 miRNAs are found to uniquely target some immune-signaling pathways, such as autophagy, IFN-I signaling, etc., which might suggest their immune-escape mechanisms for prolonged latency inside some hosts without any symptoms of COVID-19. Furthermore, SARS-CoV-2 can modulate several important cellular pathways that might lead to the increased anomalies in patients with comorbidities like cardiovascular diseases, diabetes, breathing complications, etc. This might suggest that miRNAs can be a key epigenetic modulator behind the overcomplications amongst the COVID-19 patients. Our results support that miRNAs of host and SARS-CoV-2 can indeed play a role in the pathogenesis which can be further concluded with more experiments. These results will also be useful in designing RNA therapeutics to alleviate the complications from COVID-19.
Social-ecological resilience is not easy to understand in relation to definition and importance. Fisher folks are usually not getting recognition and importance by policymakers as well as nation. ...They faced several problems, and eventually, they are living with disasters. Fishers’ social-ecological resilience depends on various factors in responding to coastal disasters including their diverse capacities and skills on innovations, social capitals, network linkages, sharing, social regulations, hazard impacts, and economic instruments with the persuasion and available options for adaptation. The poor fishers often settle in the risky areas after immediate disasters for a bundle of benefits and opportunities in the risky areas. What happens with the social-ecological knowledge and resilience in relation to context and time? Local knowledge helps become resilient. Declined social bondage, norms, minimal innovations, and low level of local knowledge integration make the fisher community vulnerable and less resilient. Comparatively, the asset-less and poor communities are the most vulnerable to coastal disasters. The shared communities stand in a better position in responding to hazards and are more resilient. The blended knowledge of proven technology and locally available practices may be an effective strategy for coastal disasters’ management. The processing technologies for diverse processed food derived from fishes and other aquatic resources are essentially important for diversified livelihood opportunities in the coastal areas to combat disasters. The proposed model and approaches will contribute to the fisher communities becoming more resilient to coastal disasters.
Plastic pollution has become a global threat in the natural environment, and an urgent remedial measure is needed to reduce the negative effects caused by plastic pollutants. In the current study, ...the effects of pyrolysis temperature (500 °C, 700 °C, and 900 °C) and aging on the adsorption of polystyrene nanoplastics (PSNPs) onto corncob biochar were systematically assessed with kinetic, isotherm, pH-dependent adsorption experiments, FTIR and XPS spectroscopy, and DLVO calculations. The oxidation was done with 5% of HNO3/H2SO4 to simulate long-term oxidative aging of biochar in the environment. The results showed that the specific surface area, hydrophobicity, and aromaticity of biochar increased with pyrolysis temperature, whereas the specific surface area and amounts of oxygen-containing groups increased after oxidation. The adsorption mechanism of PSNPs onto the biochar was explored based on the correlation between biochar properties and adsorption parameters derived from adsorption isotherms. Overall, the adsorption capacity of biochar for PSNPs increased with increased pyrolysis temperature and after aging. While the increase of specific surface area was considered the major factor leading to the increase of the adsorption, the variation in surface properties also played an important role. Pore filling, hydrophobic interaction, and hydrogen bonding may all be involved in PSNPs adsorption to biochar. However, the hydrophobic interaction might be more important for the fresh biochar, whereas hydrogen bonding involving oxygen-containing groups might make a bigger contribution to PSNPs adsorption to oxidized biochar. The pH experiments revealed that PSNPs adsorption decreased in general with the increase of pH, indicating that electrostatic repulsion played a vital role in the PSNPs adsorption process. The results of this study indicate that biochar can be potentially applied to immobilize plastic particles in terrestrial ecosystems such as in soil or groundwater, and the immobilization could be enhanced via artificial oxidation or aging of biochar in the natural environment.
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•Biochar presented strong potential for the adsorption of PSNPs.•Adsorption capacity of biochar for PSNPs increased with increased pyrolysis temperature and after aging.•Pore filling, hydrophobic interaction and hydrogen bonding all involved in PSNPs adsorption to biochar.
The pharmacological effects of limonene, especially their derivatives, are currently at the forefront of research for drug development and discovery as well and structure-based drug design using huge ...chemical libraries are already widespread in the early stages of therapeutic and drug development. Here, various limonene derivatives are studied computationally for their potential utilization against the capsid protein of Herpes Simplex Virus-1. Firstly, limonene derivatives were designed by structural modification followed by conducting a molecular docking experiment against the capsid protein of Herpes Simplex Virus-1. In this research, the obtained molecular docking score exhibited better efficiency against the capsid protein of Herpes Simplex Virus-1 and hence we conducted further in silico investigation including molecular dynamic simulation, quantum calculation, and ADMET analysis. Molecular docking experiment has documented that Ligands 02 and 03 had much better binding affinities (- 7.4 kcal/mol and - 7.1 kcal/mol) to capsid protein of Herpes Simplex Virus-1 than Standard Acyclovir (- 6.5 kcal/mol). Upon further investigation, the binding affinities of primary limonene were observed to be slightly poor. But including the various functional groups also increases the affinities and capacity to prevent viral infection of the capsid protein of Herpes Simplex Virus-1. Then, the molecular dynamic simulation confirmed that the mentioned ligands might be stable during the formation of drug-protein complexes. Finally, the analysis of ADMET was essential in establishing them as safe and human-useable prospective chemicals. According to the present findings, limonene derivatives might be a promising candidate against the capsid protein of Herpes Simplex Virus-1 which ultimately inhibits Herpes Simplex Virus-induced encephalitis that causes interventions in brain inflammation. Our findings suggested further experimental screening to determine their practical value and utility.
Despite the beneficial aspect of aquatic food's consumption, bioaccumulation of toxic metals in fish can enhance the health risk for the consumers. Heavy metals were measured from editable tissues of ...some commercial fish species like Latis calcarifer, Silonia silondia, Clupisoma garua, Planiliza subviridis, Otolithoides pama, Tenulosa ilisa, Rhinomugil corsula, and Aila coila in the Meghna river estuary in Noakhali district. Heavy metals such as As, Pb, Cd, Cu, and Cr were detected by ICP-MS, which were significantly different (p ≤ 0.01), and the hierarchy of all mean concentrations were: Cu (5.14 mg/kg) > Pb (3.79 mg/kg) > As (1.08 mg/kg) > Cr (0.78 mg/kg) > Cd (0.12 mg/kg). The mean concentration of Cu (6.62 mg/kg) imparted to the maximum level in L. calcarifer, which slightly exceeded the Bangladesh food safety guideline. The mean BAFs of the contaminants were found as: Pb (1042.29) > Cr (1036.47) > As (934.84) > Cd (832.77) > Cu (772). Further, L. calcarifer, S. silondia, C. garua, and P. subviridis showed the bioaccumulative status. To assess the health risk effects, estimated daily intake (EDI), target hazard quotient (THQ) and carcinogenic risk (CR) were conducted. THQs for both adult and children consumers were <1, indicating that, consumers would not experience the non-carcinogenic health effects. Although children were more susceptible than adults, CR for all the consumers was found in the acceptable range (10−6 to 10−4).
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•In most cases, the concentration level of metals in the fish species were lower than some approved guidelines.•Mostly, fish species were bioaccumulative in the Meghna river estuary.•Calculated THQ, HI, and CR were in acceptable range.•Children consumer were higher susceptible than adults.
Arsenic (As) and cadmium (Cd) are nonessential toxic metal(loids) that are carcinogenic to humans. Hence, reducing the bioavailability of these metal(loids) in soils and decreasing their accumulation ...in rice grains is essential for agroecology, food safety, and human health. Iron (Fe)-enriched corncob biochar (FCB), Fe-enriched charred eggshell (FEB), and Fe-enriched corncob-eggshell biochar (FCEB) were prepared for soil amelioration. The amendment materials were applied at 1% and 2% application rates to observe their alleviation effects on As and Cd loads in rice paddy tissues and yield improvements using pot trials. The FCEB treatment increased paddy yields compared to those of FCB (9–12%) and FEB (3–36%); this could be because it contains more plant essential nutrients than FCB and a lower calcite content than that of FEB. In addition, FCEB significantly reduced brown rice As (AsBR, 29–60%) and Cd (CdBR, 57–81%) contents compared to those of the untreated control (CON). At a 2% application rate, FCEB reduced the average mobility of As (56%) and Cd (62%) in rhizosphere porewater and enhanced root Fe-plaque formation (76%) compared to those of CON. Moreover, the enhanced Fe-plaque sequestered a substantial amount of As (171.4%) and Cd (90.8%) in the 2% FCEB amendment compared to that of CON. Pearson correlation coefficients and regression analysis indicated that two key mechanisms likely control AsBR and CdBR accumulations. First, rhizosphere soil pH and Eh controlled As and Cd availabilities in porewaters and their speciation in the soil. Second, greater Fe-plaque formation in paddy roots grown in the amended soils provided a barrier for plant uptake of the metal(loids). These observations demonstrate that soil amendment with Fe-enriched corncob-eggshell biochar (e.g., 2% FCEB) is a prospective approach for the remediation of metal accumulation from the soil to grain system while simultaneously increasing paddy yield.
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•Fe-enriched corncob (FCB), eggshell (FEB), and corncob-eggshell biochar (FCEB) were used.•FCEB increased 12% and 36% grain yield than FCB and FEB, respectively at 2% rate.•2% FCEB significantly reduced grain As (AsBR, 60%) and Cd (CdBR, 81%).•Porewater and root Fe-plaque As showed similar contribution on AsBR accumulation.•Fe-plaque Cd showed higher contribution than porewater Cd on CdBR accumulation.
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