Evaluation of the hydrogeochemical processes governing the heavy metal distribution and the associated health risk is important in managing and protecting the health of freshwater resources. This study mainly focused on the health impacts due to the heavy metals pollution in a known Cretaceous-Tertiary (K/T) contact region (Tiruchinopoly, Tamilnadu) of peninsular India, using various pollution indices, statistical, and geochemical analyses. A total of 63 samples were collected from the hard rock aquifers and sedimentary formations during southwest monsoon and analysed for heavy metals, such as Li, Be, Al, Rb, Sr, Cs, Ba, pb, Mn, Fe, Cr, Zn, Ga, Cu, As, Ni, and Co. Ba was the dominant element that ranged from 441 to 42,638 μg/l in hard rock aquifers, whereas Zn was the major element in sedimentary formations, with concentrations that ranged from 44 to 118,281 μg/l. The concentrations of Fe, Ni, Cr, Al, Cr, and Ni fell above the permissible limit in both of the formations. However, the calculated heavy metal evaluation index (HEI), heavy metal pollution index (HPI), and the degree of contamination (Cd) parameters were higher in the sedimentary formation along the contact zone of the K/T boundary. Excessive health risks from consumption of contaminated groundwater were mostly confined to populations in the northern and southwestern regions of the study area. Carcinogenic risk assessment suggests that there are elevated risks of cancer due to prolonged consumption of untreated groundwater. Ba, Sr, and Zn were found to be geochemically highly mobile due to the partitioning between the rock matrix and groundwater, aided by the formation of soluble carbonato-complexes. Factor analysis indicates that the metals are mainly derived from the host rocks and anthropogenic inputs are relatively insignificant. Overall, this study indicated that groundwater in K/T contact zones is vulnerable to contamination because of the favorable geochemical factors. Long-term monitoring of such contact zones is required to avert the potential health hazards associated with consumption of the contaminated groundwater.
The study aims to determine the impact of global meteorological parameters on SARS-COV-2, including population density and initiation of lockdown in twelve different countries. The daily trend of these parameters and COVID-19 variables from February 15th to April 25th, 2020, were considered. Asian countries show an increasing trend between infection rate and population density. A direct relationship between the time-lapse of the first infected case and the period of suspension of movement controls the transmissivity of COVID-19 in Asian countries. The increase in temperature has led to an increase in COVID-19 spread, while the decrease in humidity is consistent with the trend in daily deaths during the peak of the pandemic in European countries. Countries with 65°F temperature and 5 mm rainfall have a negative impact on COVID-19 spread. Lower oxygen availability in the atmosphere, fine droplets of submicron size together with infectious aerosols, and low wind speed have contributed to the increase in total cases and mortality in Germany and France. The onset of the D614G mutation and subsequent changes to D614 before March, later G614 in mid-March, and S943P, A831V, D839/Y/N/E in April were observed in Asian and European countries. The results of the correlation and factor analysis show that the COVID-19 cases and the climatic factors are significantly correlated with each other. The optimum meteorological conditions for the prevalence of G614 were identified. It was observed that the complex interaction of global meteorological factors and changes in the mutational form of CoV-2 phase I influenced the daily mortality rate along with other comorbid factors. The results of this study could help the public and policymakers to create awareness of the COVID-19 pandemic.
Evidence suggests that prolonged blue-light exposure can impact vision; however, less is known about its impact on non-visual higher-order functions in the brain, such as learning and memory. Blue-light-blocking lenses (BBLs) claim to reduce these potential impacts. Hence, we assessed structural and functional hippocampal alterations following blue-light exposure and the protective efficacy of BBLs. Male Wistar rats were divided into (n = 6 in each group) normal control (NC), blue-light exposure (LE), and blue-light with BBLs (Crizal Prevencia, CP and DuraVision Blue, DB) groups. After 28 days of light exposure (12:12 light: dark cycle), rats were trained for the Morris water maze memory retention test, and brain tissues were sectioned for hippocampal neuronal analysis using Golgi and Cresyl violet stains. The memory retention test was significantly delayed (p < 0.05) in LE compared with DB groups on day 1 of training. Comparison of Golgi-stained neurons showed significant structural alterations, particularly in the basal dendrites of hippocampal neurons in the LE group, with BBLs significantly mitigating these structural changes (p < 0.05). Comparison of Cresyl-violet-stained neurons revealed significantly (p < 0.001) increased degenerated hippocampal neurons in LE rats, with fewer degenerated neurons in the CP lens group for CA1 neurons (p < 0.05), and for both CP and DB groups (p < 0.05) for CA3 neurons. Thus, in addition to documented effects on visual centers, high-level blue-light exposure also results in degeneration in hippocampal neurons with associated behavioral deficits. These changes can be partially ameliorated with blue-light-blocking lenses.
The current work aimed to investigate the degradation of the triclocarban (TCC) in aqueous solution using a modified zeolite/TiO2 composite (MZTC) synthesized by applying the electrochemical anodization (ECA). The synthesis process was conducted at different voltages (10, 40, and 60) V in 1 h and using electrophoresis deposition (EPD) in doping zeolite. The MZTC was covered with the array ordered, smooth and optimum elongated nanotubes with 5.1 μm of the length, 120.3 nm of the inner diameter 14.5 nm of the wall thickness with pure titanium and crystalline titania as determined by FESEM/EDS, and XRD. The kinetic study by following Langmuir-Hinshelwood(L-H) model and pseudo first order, the significant constant rate was obtained at pH 11 which was 0.079 ppm/min, 0.75 cm2 of MZTC catalyst loading size achieved 0.076 ppm/min and 5 ppm of TCC initial concentration reached 0.162 ppm/min. The high-performance liquid chromatography (HPLC) analysis for mechanism study of TCC photocatalytic degradation revealed eleven intermediate products after the whole process of photocatalysis. In regard of toxicology assessment by the bacteria which is Photobacterium phosphoreum, the obtained concentration of TCC at minute 60 was less satisfied with remained 0.36 ppm of TCC was detected indicates that the concentration was above allowable level. Where the allowable level of TCC in stream is 0.1 ppm.
Identifying highly stable, cost-effective, platinum-free, and efficient electrocatalysts for the oxygen reduction reaction (ORR) remains a formidable challenge. The ORR is important for advancing fuel cell and zinc-air battery (ZAB) technologies towards cost-efficiency and environmental sustainability. This work presents the utilization of economically viable materials through a straightforward synthesis process, exhibiting the development of efficient Mo2C/Fe3C-NC catalysts ingeniously derived from phosphomolybdic acid (PMA) and iron phthalocyanine (FePc). The results demonstrate that the optimized Mo2C/Fe3C-NC3 catalysts exhibit remarkable electrochemical performance, evidenced by an impressive onset potential of ∼1.0 V versus RHE, a half-wave potential of 0.89 V, and a superior current density of about 6.2 mA cm-2. As for their performance in ZABs, the optimized catalysts reach a peak power density of 142 mW cm-2 at a current density of 200 mA cm-2. This synergy, coupled with the uniform distribution of Mo2C and Fe3C nanoparticles, greatly enhances the active catalytic sites and promotes electrolyte diffusion. Our approach diverges from traditional methods by employing an in situ self-assembled heterostructure of Mo2C/Fe3C on nitrogen-doped carbon tubes, avoiding the conventional high-temperature hydrogen gas reduction process. Beyond serving as feasible alternatives to commercially available Pt/C catalysts, these materials hold promise for large-scale production owing to their affordability and the simplicity of the synthesis technique. Such a breakthrough paves the way towards the realization of sustainable energy technologies and lays the groundwork for further exploration into amplifying the scalability and efficiency of ORR catalysts.
Silver diamine fluoride (SDF) is commonly used to arrest caries lesions, especially in early childhood caries. Recently, it was suggested that SDF can be combined with potassium iodide (KI) to minimize the discoloration of demineralized dentine associated with SDF application. However, the antibacterial efficacy of SDF alone or combined with KI on in-situ biofilm is unknown. Hence, we compared the anti-plaque biofilm efficacy of two different commercially available SDF solutions, with or without KI, using an in-situ biofilm, analysed using viability real-time PCR with propidium monoazide (PMA). Appliance-borne in-situ biofilm samples (n = 90) were grown for a period of 6 h in five healthy subjects who repeated the experiment on three separate occasions, using a validated, novel, intraoral device. The relative anti-biofilm efficacy of two SDF formulations; 38.0% Topamine (SDFT) and 31.3%, Riva Star (SDFR), KI alone, and KI in combination with SDFR (SDFR+KI) was compared. The experiments were performed by applying an optimized volume of the agents onto the biofilm for 1min, mimicking the standard clinical procedure. Afterwards the viability of the residual biofilm bacteria was quantified using viability real-time PCR with PMA, then the percentage of viable from total bacteria was calculated. Both SDF formulations (SDFT and SDFR) exhibited potent antibacterial activities against the in-situ biofilm; however, there was non-significant difference in their efficacy. KI alone did not demonstrate any antibacterial effect, and there was non-significant difference in the antibacterial efficacy of SDF alone compared to SDF with KI, (SDFT v SDFR/KI). Thus, we conclude that the antibacterial efficacy of SDF against plaque biofilms is not modulated by KI supplements. Viability real-time PCR with PMA was successfully used to analyze the viability of naturally grown oral biofilm; thus, the same method can be used to test the antimicrobial effect of other agents on oral biofilms in future research.
Bio-electrochemical systems (BESs) are the microbial systems which are employed to produce electricity directly from organic wastes along with some valuable chemicals production such as medium chain fatty acids; acetate, butyrate and alcohols. In this review, recent updates about value-added chemicals production concomitantly with the production of gaseous fuels like hydrogen and methane which are considered as cleaner for the environment have been addressed. Additionally, the bottlenecks associated with the conversion rates, lower yields and other aspects have been mentioned. In spite of its infant stage development, this would be the future trend of energy, biochemicals and electricity production in greener and cleaner pathway with the win-win situation of organic waste remediation. Henceforth, this review intends to summarise and foster the progress made in the BESs and discusses its challenges and outlook on future research advances.
Microbial electrochemical systems (MESs) are an attracting technology for the disposal of wastewater treatment and simultaneous energy production. In MESs, at the anode microorganisms through the catalytic activity generates electrons that can be converted into electricity or other valuable chemical compounds. Microorganisms those having ability to donate and accept electrons to and from anode and cathode electrodes, respectively are recognized as 'exoelectrogens'. In the MESs, it renders an important function for its performance. In the present mini-review, we have discussed the role of microbiome including pure culture, enriched culture and mixed culture in different BESs application. The effects of operational and biological factors on microbiome development have been discussed. Further discussion about the molecular techniques for the evaluation of microbial community analysis is addressed. In addition different electrochemical techniques for extracellular electron transfer (EET) mechanism of electroactive biofilms have been discussed. This review highlights the importance of microbiome in the development of MESs, effective operational factors for exo-electrogens activities as well their key challenges and future technological aspects are also briefly discussed.
This review provides the alternative routes towards the valorization of dark H2 fermentation effluents that are mainly rich in volatile fatty acids such as acetate and butyrate. Various enhancement and alternative routes such as photo fermentation, anaerobic digestion, utilization of microbial electrochemical systems, and algal system towards the generation of bioenergy and electricity and also for efficient organic matter utilization are highlighted. What is more, various integration schemes and two-stage fermentation for the possible scale up are reviewed. Moreover, recent progress for enhanced performance towards waste stabilization and overall utilization of useful and higher COD present in the organic source into value-added products are extensively discussed.
This study focuses on the biochar formation and torrefaction performance of sugarcane bagasse, and they are predicted using the bilinear interpolation (BLI), inverse distance weighting (IDW) interpolation, and regression analysis. It is found that the biomass torrefied at 275°C for 60min or at 300°C for 30min or longer is appropriate to produce biochar as alternative fuel to coal with low carbon footprint, but the energy yield from the torrefaction at 300°C is too low. From the biochar yield, enhancement factor of HHV, and energy yield, the results suggest that the three methods are all feasible for predicting the performance, especially for the enhancement factor. The power parameter of unity in the IDW method provides the best predictions and the error is below 5%. The second order in regression analysis gives a more reasonable approach than the first order, and is recommended for the predictions.
Steam gasification of microalgae upon perovskite oxide-supported nickel (Ni) catalysts was carried out for H2-rich gas production. Ni-perovskite oxide catalysts with partial substitution of B in perovskite structures (Ni/CaZrO3, Ni/Ca(Zr0.8Ti0.2)O3, and Ni/Ca(Zr0.6Ti0.4)O3) were synthesized and compared with those of the Ni/Al2O3 catalyst. The perovskite oxide supports improved Ni dispersion by reducing the particle size and strengthening the Ni-support interaction. Higher gas yields and H2 selectivity were obtained using Ni-perovskite oxide catalysts rather than Ni/Al2O3. In particular, Ni/Ca(Zr0.8Ti0.2)O3 showed the highest activity and selectivity for H2 production because of the synergetic effect of metallic Ni and elements present in the perovskite structures caused by high catalytic activity coupled with enhanced oxygen mobility. Moreover, increasing the temperature promoted the yield of gas and H2 content. Overall, considering the outstanding advantages of perovskite oxides as supports for Ni catalysts is a promising prospect for H2 production via gasification technology.
Serratia marcescens is an opportunistic human pathogen that causes urinary tract infections, ocular lens infections, and respiratory tract infections. S. marcescens employs various defense mechanisms to evade antibiotics, one of which is mediated by aminoglycoside N-acetyltransferase (AAC). In this mechanism, the enzyme AAC facilitates the transfer and linkage of the acetyl moiety from the donor substrate acetyl-coenzyme A to specific positions on antibiotics. This modification alters the antibiotic's structure, leading to the inactivation of aminoglycoside antibiotics. In the current scenario, antibiotic resistance has become a global threat, and targeting the enzymes that mediate resistance is considered crucial to combat this issue. The study aimed to address the increasing global threat of antibiotic resistance in Serratia marcescens by targeting the aminoglycoside N-acetyltransferase (AAC (6')) enzyme, which inactivates aminoglycoside antibiotics through acetylation. Due to the absence of experimental structure, we constructed a homology model of aminoglycoside N (6')-acetyltransferase (AAC (6')) of S. marcescens using the atomic structure of aminoglycoside N-acetyltransferase AAC (6')-Ib (PDB ID: 1V0C) as a template. The stable architecture and integrity of the modelled AAC (6') structure were analyzed through a 100 ns simulation. Structure-guided high-throughput screening of four small molecule databases (Binding, Life Chemicals, Zinc, and Toslab) resulted in the identification of potent inhibitors against AAC (6'). The hits obtained from screening were manually clustered, and the five hit molecules were shortlisted based on the docking score, which are observed in the range of -17.09 kcal/mol to -11.95 kcal/mol. These selected five molecules displayed acceptable pharmacological properties in ADME predictions. The binding free energy calculations, and molecular dynamics simulations of ligand bound AAC (6') complexes represented higher affinity and stable binding. The selected molecules demonstrated stable binding with AAC (6'), indicating their strong potential to hamper the binding of aminoglycoside in the respective site. and thereby inhibit. This process mitigates enzyme mediated AAC (6') activity on aminoglycosides and reverse the bactericidal function of aminoglycosides, and also this method could serve as a platform for the development of potential antimicrobials.
Recently, the production of renewable biogas such as biohydrogen and biomethane from wastewaters through anaerobic fermentation has gained worldwide attention. In the present study, a mobile bioenergy generation station had been constructed based on a high-efficiency hydrogenesis & methanogenesis technology (HyMeTek) developed by Feng Chia University, Taiwan. The substrate was a beverage wastewater having chemical oxygen demand (COD) concentration of 1200 mg/L. This bioenergy station had a feedstock tank (3.8 m3), a nutrient tank (0.8 m3), an acidogenesis tank (AT, 2 m3), two methanogenesis tanks (MT, 4 m3 for each), a membrane bioreactor and a control room. Biogas production rate, methane concentration, COD removal efficiencies, energy efficiency and economical interest of the plant were assessed. The peak total methane production rates for AT (at hydraulic retention time, HRT, 4 h) and MT (at HRT 8 h) were 430 and 7 mL/L·d, respectively. A strategy of shortening HRT was a promising method to enhance biogas quality and energy efficiency. This mobile bioenergy system has commercial potential because it could bring good economic benefit of initial rate of return (58.84%) and payback time (2.68 y).
Microbial electrolysis cells (MECs) are perceived as a potential and promising innovative biotechnological tool that can convert carbon-rich waste biomass or wastewater into hydrogen (H2) or other value-added chemicals. Undesired methane (CH4) producing H2 sinks, including methanogens, is a serious challenge faced by MECs to achieve high-rate H2 production. Methanogens can consume H2 to produce CH4 in MECs, which has led to a drop of H2 production efficiency, H2 production rate (HPR) and also a low percentage of H2 in the produced biogas. Organized inference related to the interactions of microbes and potential processes has assisted in understanding approaches and concepts for inhibiting the growth of methanogens and profitable scale up design. Thus, here in we review the current developments and also the improvements constituted for the reduction of microbial H2 losses to methanogens. Firstly, the greatest challenge in achieving practical applications of MECs; undesirable microorganisms (methanogens) growth and various studied techniques for eliminating and reducing methanogens activities in MECs were discussed. Additionally, this extensive review also considers prospects for stimulating future research that could help to achieve more information and would provide the focus and path towards MECs as well as their possibilities for simultaneously generating H2 and waste remediation.
Zinc (Zn) is an excellent material for use as an anode for rechargeable batteries in water-based electrolytes. Nevertheless, the high activity of water leads to Zn corrosion and hydrogen evolution, along with the formation of dendrites on the Zn surface during repeated charge-discharge (CD) cycles. To protect the Zn anode and limit parasitic side reactions, an artificial solid electrolyte interphase (ASEI) protective layer is an effective strategy. Herein, an ASEI made of a covalent organic framework (COFs: HqTp and BpTp) was fabricated on the surface of a Zn anode via Schiff base reactions of aldehyde and amine linkers. It is seen that COFs can regulate the Zn-ion flux, resulting in dendritic-free Zn. COFs can also mitigate the formation of an irreversible passive layer and the hydrogen evolution reaction (HER). Zn plating/stripping tests using a symmetrical cell suggest that HqTpCOF@Zn shows superior stability and greater coulombic efficiency (CE) compared to bare Zn. The full cell having COFs@Zn also displays much improved cyclability. As a result, the COF proves to be a promising ASEI material to enhance the stability of the Zn anode in aqueous media.
The Sardinian dhole (Cynotherium sardous)1 was an iconic and unique canid species that was endemic to Sardinia and Corsica until it became extinct at the end of the Late Pleistocene.2-5 Given its peculiar dental morphology, small body size, and high level of endemism, several extant canids have been proposed as possible relatives of the Sardinian dhole, including the Asian dhole and African hunting dog ancestor.3,6-9 Morphometric analyses3,6,8-12 have failed to clarify the evolutionary relationship with other canids.We sequenced the genome of a ca-21,100-year-old Sardinian dhole in order to understand its genomic history and clarify its phylogenetic position. We found that it represents a separate taxon from all other living canids from Eurasia, Africa, and North America, and that the Sardinian dhole lineage diverged from the Asian dhole ca 885 ka. We additionally detected historical gene flow between the Sardinian and Asian dhole lineages, which ended approximately 500-300 ka, when the land bridge between Sardinia and mainland Italy was already broken, severing their population connectivity. Our sample showed low genome-wide diversity compared to other extant canids-probably a result of the long-term isolation-that could have contributed to the subsequent extinction of the Sardinian dhole.
Large vertebrates are extremely sensitive to anthropogenic pressure, and their populations are declining fast. The white rhinoceros (Ceratotherium simum) is a paradigmatic case: this African megaherbivore has suffered a remarkable decline in the last 150 years due to human activities. Its subspecies, the northern (NWR) and the southern white rhinoceros (SWR), however, underwent opposite fates: the NWR vanished quickly, while the SWR recovered after the severe decline. Such demographic events are predicted to have an erosive effect at the genomic level, linked to the extirpation of diversity, and increased genetic drift and inbreeding. However, there is little empirical data available to directly reconstruct the subtleties of such processes in light of distinct demographic histories. Therefore, we generated a whole-genome, temporal data set consisting of 52 resequenced white rhinoceros genomes, representing both subspecies at two time windows: before and during/after the bottleneck. Our data reveal previously unknown population structure within both subspecies, as well as quantifiable genomic erosion. Genome-wide heterozygosity decreased significantly by 10% in the NWR and 36% in the SWR, and inbreeding coefficients rose significantly by 11% and 39%, respectively. Despite the remarkable loss of genomic diversity and recent inbreeding it suffered, the only surviving subspecies, the SWR, does not show a significant accumulation of genetic load compared to its historical counterpart. Our data provide empirical support for predictions about the genomic consequences of shrinking populations, and our findings have the potential to inform the conservation efforts of the remaining white rhinoceroses.
Piper longum (family Piperaceae), commonly known as "long-pepper" or "Pippali" grows as a perennial shrub or as an herbaceous vine. It is native to the Indo-Malaya region and widely distributed in the tropical and subtropical world including the Indian subcontinent, Sri Lanka, Middle-East, and America. The fruits are mostly used as culinary spice and preservatives and are also a potent remedy in various traditional medicinal systems against bronchitis, cough, cold, snakebite, and scorpion-sting and are also used as a contraceptive. Various bioactive-phytochemicals including alkaloids, flavonoids, esters, and steroids were identified from the plant extracts and essential oils from the roots and fruits were reported as antimicrobial, antiparasitic, anthelminthic, mosquito-larvicidal, antiinflammatory, analgesic, antioxidant, anticancer, neuro-pharmacological, antihyperglycaemic, hepato-protective, antihyperlipidaemic, antiangiogenic, immunomodulatory, antiarthritic, antiulcer, antiasthmatic, cardioprotective, and anti-snake-venom agents. Many of its pharmacological properties were attributed to its antioxidative and antiinflammatory effects and its ability to modulate a number of signalling pathways and enzymes. This review comprehensively encompasses information on habit, distribution, ethnobotany, phytochemistry, and pharmacology of P. longum in relation to its medicinal importance and health benefits to validate the traditional claims supported by specific scientific experiments. In addition, it also discusses the safety and toxicity studies, application of green synthesis and nanotechnology as well as clinical trials performed with the plant also elucidating research gaps and future perspectives of its multifaceted uses.
Indigenous maize varieties from eastern North America have played an outsized role in breeding programs, yet their early origins are not fully understood. We generated paleogenomic data to reconstruct how maize first reached this region and how it was selected during the process. Genomic ancestry analyses reveal recurrent movements northward from different parts of Mexico, likely culminating in at least two dispersals from the US Southwest across the Great Plains to the Ozarks and beyond. We find that 1,000-year-old Ozark specimens carry a highly differentiated wx1 gene, which is involved in the synthesis of amylose, highlighting repeated selective pressures on the starch metabolic pathway throughout maize's domestication. This population shows a close affinity with the lineage that ultimately became the Northern Flints, a major contributor to modern commercial maize.
Biohydrogen as one of the most appealing energy vector for the future represents attractive avenue in alternative energy research. Recently, variety of biohydrogen production pathways has been suggested to improve the key features of the process. Nevertheless, researches are still needed to overcome remaining barriers to practical applications such as low yields and production rates. Considering practicality aspects, this review emphasized on anaerobic membrane bioreactors (AnMBRs) for biological hydrogen production. Recent advances and emerging issues associated with biohydrogen generation in AnMBR technology are critically discussed. Several techniques are highlighted that are aimed at overcoming these barriers. Moreover, environmental and economical potentials along with future research perspectives are addressed to drive biohydrogen technology towards practicality and economical-feasibility.