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Biosensors Jun 2024Heavy metals constitute pollutants that are particularly common in air, water, and soil. They are present in both urban and rural environments, on land, and in marine...
Heavy metals constitute pollutants that are particularly common in air, water, and soil. They are present in both urban and rural environments, on land, and in marine ecosystems, where they cause serious environmental problems since they do not degrade easily, remain almost unchanged for long periods, and bioaccumulate. The detection and especially the quantification of metals require a systematic process. Regular monitoring is necessary because of seasonal variations in metal levels. Consequently, there is a significant need for rapid and low-cost metal determination methods. In this study, we compare and analytically validate absorption spectrometry with a sensitive voltammetric method, which uses a bismuth film-plated electrode surface and applies stripping voltammetry. Atomic absorption spectroscopy (AAS) represents a well-established analytical technique, while the applicability of anodic stripping voltammetry (ASV) in complicated sample matrices such as soil samples is currently unknown. This sample-handling challenge is investigated in the present study. The results show that the AAS and ASV methods were satisfactorily correlated and showed that the metal concentration in soils was lower than the limit values but with an increasing trend. Therefore, continuous monitoring of metal levels in the urban complex of a city is necessary and a matter of great importance. The limits of detection of cadmium (Cd) were lower when using the stripping voltammetry (SWASV) graphite furnace technique compared with those obtained with AAS when using the graphite furnace. However, when using flame atomic absorption spectroscopy (flame-AAS), the measurements tended to overestimate the concentration of Cd compared with the values found using SWASV. This highlights the differences in sensitivity and accuracy between these analytical methods for detecting Cd. The SWASV method has the advantage of being cheaper and faster, enabling the simultaneous determination of heavy elements across the range of concentrations that these elements can occur in Mediterranean soils. Additionally, a dsDNA biosensor is suggested for the discrimination of Cu(I) along with Cu(II) based on the oxidation peak of guanine, and adenine residues can be applied in the redox speciation analysis of copper in soil, which represents an issue of great importance.
Topics: Bismuth; Metals, Heavy; Electrodes; Soil; DNA; Biosensing Techniques; Soil Pollutants; Electrochemical Techniques; Spectrophotometry, Atomic; Cadmium
PubMed: 38920614
DOI: 10.3390/bios14060310 -
Environmental Geochemistry and Health Jun 2024A simple sol-gel combustion process was employed for the creation of MFeO (M=Ni, Co) nanoparticles. The synthesized nanoparticles, acting as both photocatalysts and gas...
A simple sol-gel combustion process was employed for the creation of MFeO (M=Ni, Co) nanoparticles. The synthesized nanoparticles, acting as both photocatalysts and gas sensors, were analyzed using various analytical techniques. MFeO (M=Ni, Co) material improved the degradation of methylene blue (MB) under UV-light irradiation, serving as an enhanced electron transport medium. UV-vis studies demonstrated that NiFeO achieved a 60% degradation, while CoFeO nanostructure exhibited a 76% degradation efficacy in the MB dye removal process. Furthermore, MFeO (M=Ni, Co) demonstrated chemosensitive-type sensor capabilities at ambient temperature. The sensor response and recovery times for CoFeO at a concentration of 100 ppm were 15 and 20, respectively. Overall, the synthesis of MFeO (M=Ni, Co) holds the potential to significantly improve the photocatalytic and gas sensing properties, particularly enhancing the performance of CoFeO. The observed enhancements make honey MFeO (M=Ni, Co) a preferable choice for environmental remediation applications.
Topics: Cobalt; Nickel; Ferric Compounds; Methylene Blue; Metal Nanoparticles; Gases; Catalysis; Ultraviolet Rays; Environmental Restoration and Remediation; Nanoparticles; Aluminum Oxide; Magnesium Oxide
PubMed: 38916678
DOI: 10.1007/s10653-024-01966-9 -
Sensors (Basel, Switzerland) Jun 2024Simultaneous dual-contrast imaging of iodine and bismuth has shown promise in prior phantom and animal studies utilizing spectral CT. However, it is noted that in...
Simultaneous dual-contrast imaging of iodine and bismuth has shown promise in prior phantom and animal studies utilizing spectral CT. However, it is noted that in previous studies, Pepto-Bismol has frequently been employed as the source of bismuth, exceeding the recommended levels for human subjects. This investigation sought to assess the feasibility of visually differentiating and precisely quantifying low-concentration bismuth using clinical dual-source photon-counting CT (PCCT) in a scenario involving both iodinated and bismuth-based contrast materials. Four bismuth samples (0.6, 1.3, 2.5, and 5.1 mg/mL) were prepared using Pepto-Bismol, alongside three iodine rods (1, 2, and 5 mg/mL), inserted into multi-energy CT phantoms with three different sizes, and scanned on a PCCT system at three tube potentials (120, 140, and Sn140 kV). A generic image-based three-material decomposition method generated iodine and bismuth maps, with mean mass concentrations and noise levels measured. The root-mean-square errors for iodine and bismuth determined the optimal tube potential. The tube potential of 140 kV demonstrated optimal quantification performance when both iodine and bismuth were considered. Distinct differentiation of iodine rods with all three concentrations and bismuth samples with mass concentrations ≥ 1.3 mg/mL was observed across all phantom sizes at the optimal kV setting.
Topics: Bismuth; Iodine; Phantoms, Imaging; Tomography, X-Ray Computed; Contrast Media; Humans; Photons
PubMed: 38894358
DOI: 10.3390/s24113567 -
Journal of Hazardous Materials Aug 2024This study investigates the co-precipitation of calcium and barium ions in hypersaline wastewater under the action of Bacillus licheniformis using microbially induced...
Co-removal and recycling of Ba and Ca in hypersaline wastewater based on the microbially induced carbonate precipitation technique: Overlooked Ba in extracellular and intracellular vaterite.
This study investigates the co-precipitation of calcium and barium ions in hypersaline wastewater under the action of Bacillus licheniformis using microbially induced carbonate precipitation (MICP) technology, as well as the bactericidal properties of the biomineralized product vaterite. The changes in carbonic anhydrase activity, pH, carbonate and bicarbonate concentrations in different biomineralization systems were negatively correlated with variations in metal ion concentrations, while the changes in polysaccharides and protein contents in bacterial extracellular polymers were positively correlated with variations in barium concentrations. In the mixed calcium and barium systems, the harvested minerals were vaterite containing barium. The increasing concentrations of calcium promoted the incorporation and adsorption of barium onto vaterite. The presence of barium significantly increased the contents of O-CO, N-CO, and Ba-O in vaterite. Calcium promoted barium precipitation, but barium inhibited calcium precipitation. After being treated by immobilized bacteria, the concentrations of calcium and barium ions decreased from 400 and 274 to 1.72 and 0 mg/L (GB/T15454-2009 and GB8978-1996). Intracellular minerals were also vaterite containing barium. Extracellular vaterite exhibited bactericidal properties. This research presents a promising technique for simultaneously removing and recycling hazardous heavy metals and calcium in hypersaline wastewater.
Topics: Wastewater; Barium; Calcium; Chemical Precipitation; Bacillus; Calcium Carbonate; Water Pollutants, Chemical; Recycling; Carbonates; Carbonic Anhydrases; Water Purification
PubMed: 38889469
DOI: 10.1016/j.jhazmat.2024.134923 -
Environmental Monitoring and Assessment Jun 2024In the current work, Response Surface Methodology (RSM)-a statistical method-is used to optimize procedures like photocatalysis with the least amount of laboratory...
In the current work, Response Surface Methodology (RSM)-a statistical method-is used to optimize procedures like photocatalysis with the least amount of laboratory testing. However, to determine the most effective model for achieving the maximum rate of removal efficiency, the Response Surface Methodology was employed. The Ba-doped BiFeO photocatalyst was synthesized by the co-precipitation method, and its intrinsic properties were investigated by utilizing a range of spectroscopic techniques, such as FESEM, EDX, XRD, FTIR, and UV-vis. Herein, four independent factors such as, pH, contact time, pollutant concentration, and catalyst dosage were chosen. The results revealed that under acidic conditions with a contact duration of 2 min, a moderate catalyst dosage, and higher pollutant concentration, a degradation rate of 89.8% was achieved. The regression coefficient (R) and probability value (P) were determined to be 0.99551 and 0.0301, respectively, therefore confirming the excellent fit of the RSM model. Furthermore, this research investigated the potential photocatalytic degradation mechanisms of cefixime, demonstrating that the removal efficiency of cefixime is greatly influenced by the functional parameters.
Topics: Catalysis; Nanostructures; Water Pollutants, Chemical; Cefixime; Bismuth; Photolysis; Photochemical Processes; Ferric Compounds
PubMed: 38884667
DOI: 10.1007/s10661-024-12781-1 -
The Pan African Medical Journal 2024people living with HIV/AIDS using antiretroviral therapy sometimes present with comorbid conditions or co-infections. This could lead to an increased risk of drug...
INTRODUCTION
people living with HIV/AIDS using antiretroviral therapy sometimes present with comorbid conditions or co-infections. This could lead to an increased risk of drug interactions due to the concomitant use of drugs. The aim of the study was to explore the overall impact of dolutegravir on such comorbidities and the effect of concomitant medication on the safety and efficacy of dolutegravir.
METHODS
data was collected using a survey questionnaire and a retrospective review of medical records of a prospective study sample. Medical records were retrospectively reviewed for up to 12 months after dolutegravir initiation. Concomitantly used drugs and supplements that were identified to have a potential interaction with dolutegravir were further characterized. Descriptive and summary statistics were used to describe the data, t-tests were performed on blood glucose levels and cross-tabulations were done on some variables.
RESULTS
of the 461 participants enrolled into the study, 172 (37.3%) and 54 (11.7%) experienced comorbidity and coinfection respectively. More than 50% of the participants used concomitant medicines. Metformin use led to increased blood glucose levels (p=0.009); participants on rifampicin (n=8) received an additional daily dose of dolutegravir. Virological outcomes in participants on sodium valproate (n=2) and St John´s wort (n=1) did not show safety concerns, whilst 3 dolutegravir discontinuations were observed in participants using supplements and antacids containing divalent cations.
CONCLUSION
even though dolutegravir was safe and effective in the study population, with possible drug interactions leading to treatment discontinuations in only 3(0.7%) participants, further investigation into dolutegravir-induced hyperglycemia needs investigation.
Topics: Humans; Pyridones; Oxazines; HIV Infections; Heterocyclic Compounds, 3-Ring; Piperazines; Female; Male; Retrospective Studies; Adult; Middle Aged; Drug Interactions; HIV Integrase Inhibitors; Prospective Studies; Comorbidity; Surveys and Questionnaires; Cohort Studies; Coinfection; Blood Glucose; Anti-HIV Agents
PubMed: 38881766
DOI: 10.11604/pamj.2024.47.137.40726 -
Carbohydrate Polymers Oct 2024While the extensive utilization of disposable plastic straws has resulted in significant environmental issues such as microplastics and soil and ocean pollution, the...
While the extensive utilization of disposable plastic straws has resulted in significant environmental issues such as microplastics and soil and ocean pollution, the quest for alternative straws for versatile use remains a formidable challenge. Here, drawing inspiration from naturally water-resistant materials such as bones and sea urchins, we have developed seaweed-based straws with significantly improved water resistance and mechanical strength via in-situ mineralization of CaCO on their surfaces. Specifically, the COO groups on the G (α-L-guluronate) blocks of alginate were employed to establish a robust cross-linked network, while the COO groups on the M (β-D-mannuronate) blocks attracted free Ca through electrostatic forces, thereby promoting CaCO nucleation. This effectively prevents COOH groups from hydrating, reducing swelling, and results in the fabrication of nano- to micron-sized CaCO particles that reinforce the structure without compromising the cross-linked network. Compared with the control group, the S5% sample (prepared with 5 % NaCO solution) exhibited a 102 % increase in water contact angle, a 35 % decrease in swelling degree, and a 35.5 % and 37.5 % increase in ultimate flexural and tensile stress, respectively. Furthermore, the potential use of these straws as a waste for heavy metal adsorption was investigated, addressing environmental concerns while demonstrating economic feasibility.
Topics: Calcium Carbonate; Seaweed; Tensile Strength; Alginates; Surface Properties; Water
PubMed: 38876717
DOI: 10.1016/j.carbpol.2024.122347 -
Helicobacter 2024The optimal dosage of tetracycline remains unclear for Helicobacter pylori eradication. Frequent dosing requirements may decrease patient adherence and increase the... (Randomized Controlled Trial)
Randomized Controlled Trial
Efficacy of Tetracycline Three Times Daily was Comparable to That of Four Times Daily for Helicobacter pylori Rescue Treatment: A Multicenter, Noninferiority, Randomized Controlled Trial.
BACKGROUND
The optimal dosage of tetracycline remains unclear for Helicobacter pylori eradication. Frequent dosing requirements may decrease patient adherence and increase the incidence of adverse events, potentially reducing treatment efficacy. This study aimed to compare the efficacy of different tetracycline dosages in rescue treatment for H. pylori infection.
METHODS
A total of 406 patients needing H. pylori rescue treatment were enrolled. Patients were randomized into two groups and received bismuth-containing quadruple therapies as follows: esomeprazole 40 mg twice daily, bismuth 220 mg twice daily, amoxicillin 1000 mg twice daily, and tetracycline 500 mg either three (TET-T group) or four (TET-F group) times daily. At least 6 weeks after treatment completion, a C-urea breath test was performed to evaluate H. pylori eradication.
RESULTS
The intention-to-treat (ITT) eradication rates were 91.13% (185/203) and 90.15% (183/203) (p = 0.733), the modified ITT (MITT) eradication rates were 94.87% (185/195) and 95.31% (183/192) (p = 0.841), and the per-protocol (PP) eradication rates were 94.79% (182/192) and 95.21% (179/188) (p = 0.851) in the TET-T group and TET-F group, respectively. The eradication rates for the TET-T group were not inferior to those of the TET-F group in ITT, MITT, and PP analyses. The incidence of adverse effects was significantly lower in the TET-T group than in the TET-F group (23.65% vs. 33.50%, p = 0.028). No significant differences were observed in treatment compliance between the groups.
CONCLUSIONS
The dose of tetracycline administered three times daily showed comparable efficacy to that administered four times daily, while significantly reducing the incidence of adverse events. The combination of tetracycline and amoxicillin in bismuth-containing quadruple therapy achieved a high eradication rate in H. pylori rescue treatment.
Topics: Humans; Helicobacter Infections; Tetracycline; Male; Female; Middle Aged; Anti-Bacterial Agents; Helicobacter pylori; Adult; Treatment Outcome; Aged; Drug Therapy, Combination; Amoxicillin; Drug Administration Schedule; Esomeprazole; Breath Tests; Bismuth
PubMed: 38873902
DOI: 10.1111/hel.13102 -
Scientific Reports Jun 2024Caudofoveata are molluscs that protect their vermiform body with a scleritome, a mosaic of unconnected blade/lanceolate-shaped aragonite sclerites. For the species...
Caudofoveata are molluscs that protect their vermiform body with a scleritome, a mosaic of unconnected blade/lanceolate-shaped aragonite sclerites. For the species Falcidens gutturosus and Scutopus ventrolineatus we studied the crystallographic constitution and crystal orientation texture of the sclerites and the scleritome with electron-backscatter-diffraction (EBSD), laser-confocal-microscopy (LCM) and field-emission electron microscopy (FE-SEM) imaging. Each sclerite is an aragonite single crystal that is completely enveloped by an organic sheath. Adjacent sclerites overlap laterally and vertically are, however, not connected to each other. Sclerites are thickened in their central portion, relative to their periphery. Thickening increases also from sclerite tip towards its base. Accordingly, cross-sections through a sclerite are straight at its tip, curved and bent towards the sclerite base. Irrespective of curved sclerite morphologies, the aragonite lattice within the sclerite is coherent. Sclerite aragonite is not twinned. For each sclerite the crystallographic c-axis is parallel to the morphological long axis of the sclerite, the a-axis is perpendicular to its width and the b-axis is within the width of the sclerite. The single-crystalinity of the sclerites and their mode of organization in the scleritome is outstanding. Sclerite and aragonite arrangement in the scleritome is not given by a specific crystal growth mode, it is inherent to the secreting cells. We discuss that morphological characteristics of the sclerites and crystallographic preferred orientation (texture) of sclerite aragonite is not the result of competitive growth selection. It is generated by the templating effect of the organic substance of the secreting cells and associated extracellular biopolymers.
Topics: Animals; Animal Shells; Mollusca; Calcium Carbonate; Crystallography; Microscopy, Electron, Scanning
PubMed: 38866846
DOI: 10.1038/s41598-024-63042-7 -
Soft Matter Jun 2024Biogenic CaCO formation is regulated by crystallization proteins during crystal growth. Interactions of proteins with nascent mineral surfaces trigger proteins to be...
Biogenic CaCO formation is regulated by crystallization proteins during crystal growth. Interactions of proteins with nascent mineral surfaces trigger proteins to be incorporated into the crystal lattice. As a result of incorporation, these intracrystalline proteins are protected in the lattice, an example of which is ancient eggshell proteins that have persisted in CaCO for thousands of years even under harsh environmental conditions. OC17 is an eggshell protein known to interact with CaCO during eggshell formation during which OC17 becomes incorporated into the lattice. Understanding protein incorporation into CaCO could offer insights into protein stability inside crystals. Here, we study the protection of OC17 in the CaCO lattice. Using thermogravimetric analysis we show that the effect of temperature on intracrystalline proteins of eggshells is negligible below 250 °C. Next, we show that lattice incorporation protects the OC17 structure despite a heat-treatment step that is shown to denature the protein. Because incorporated proteins need to be released from crystals, we verify metal chelation as a safe crystal dissolution method to avoid protein denaturation during reconstitution. Finally, we optimize the recombinant expression of OC17 which could allow engineering OC17 for engineered intracrystalline entrapment studies.
Topics: Calcium Carbonate; Egg Proteins; Crystallization; Animals; Temperature
PubMed: 38860646
DOI: 10.1039/d4sm00371c