Evaluation of a Smectite Adsorption-Based Electrostatic System to Decontaminate F− Rich Thermal Waters

Several studies have shown the presence of fluoride levels much higher than the 1.5 mg/L threshold concentration recommended by WHO in the spring waters and wells of the Ethiopian Rift Valley. Available defluoridation techniques can be costly, present complicated technical aspects, and show limited effectiveness. Therefore, it is necessary to devise innovative, sustainable, and effective solutions. This study proposes an alternative method of intervention to the known techniques for removing fluoride from water, particularly suitable for smaller rural communities. In particular, in this work, the possibility to use electromagnetic fields as a physical method for removing the excess fluoride was investigated. The study was carried out by developing a multiphysics model used for studying and envisaging the design of a device. In this framework, the combination of this approach with the use of highly reactive smectite clay was numerically studied. The results obtained, although preliminary, indicate that the proposed system could significantly impoverish the waters of the Rift Valley from fluoride, with the consequence of obtaining a resource suitable for human consumption, in particular for rural communities. However, further theoretical investigations and experimental phases will be necessary to achieve the desired results.

The Environmental Pollutant Bromophenols Interfere With Sulfotransferase That Mediates Endocrine Hormones

Bromophenols (BPs), known as an important environmental contaminant, can cause endocrine disruption and other chronic toxicity. The study aimed to investigate the potential inhibitory capability of BPs on four human sulfotransferase isoforms (SULT1A1, SULT1A3, SULT1B1 and SULT1E1) and interpret how to interfere with endocrine hormone metabolism. P-nitrophenol(PNP) was utilized as a nonselective probe substrate, and recombinant SULT isoforms were utilized as the enzyme resources. PNP and its metabolite PNP-sulfate were analyzed using a UPLC-UV detecting system. SULT1A1 and SULT1B1 were demonstrated to be the most vulnerable SULT isoforms towards BPs’ inhibition. To determine the inhibition kinetics, 2,4,6-TBP and SULT1A3 were selected as the representative BPs and SULT isoform respectively. The competitive inhibition of 2,4,6-TBP on SULT1A3. The fitting equation was y=90.065x+1466.7, and the inhibition kinetic parameter (Ki) was 16.28 µM. In vitro-in vivo extrapolation (IVIVE) showed that the threshold concentration of 2,4,6-TBP to induce inhibition of SULT1A3 was 1.628 µM. In silico docking, the method utilized indicated that more hydrogen bonds formation contributed to the stronger inhibition of 3,5-DBP than 3-BP. In conclusion, our study gave the full description of the inhibition of BPs towards four SULT isoforms, which may provide a new perspective on the toxicity mechanism of BPs and further explain the interference of BPs on endocrine hormone metabolism.

HDAC Inhibitor Titration of Transcription and Axolotl Tail Regeneration

New patterns of gene expression are enacted and regulated during tissue regeneration. Histone deacetylases (HDACs) regulate gene expression by removing acetylated lysine residues from histones and proteins that function directly or indirectly in transcriptional regulation. Previously we showed that romidepsin, an FDA-approved HDAC inhibitor, potently blocks axolotl embryo tail regeneration by altering initial transcriptional responses to injury. Here, we report on the concentration-dependent effect of romidepsin on transcription and regeneration outcome, introducing an experimental and conceptual framework for investigating small molecule mechanisms of action. A range of romidepsin concentrations (0–10 μM) were administered from 0 to 6 or 0 to 12 h post amputation (HPA) and distal tail tip tissue was collected for gene expression analysis. Above a threshold concentration, romidepsin potently inhibited regeneration. Sigmoidal and biphasic transcription response curve modeling identified genes with inflection points aligning to the threshold concentration defining regenerative failure verses success. Regeneration inhibitory concentrations of romidepsin increased and decreased the expression of key genes. Genes that associate with oxidative stress, negative regulation of cell signaling, negative regulation of cell cycle progression, and cellular differentiation were increased, while genes that are typically up-regulated during appendage regeneration were decreased, including genes expressed by fibroblast-like progenitor cells. Using single-nuclei RNA-Seq at 6 HPA, we found that key genes were altered by romidepin in the same direction across multiple cell types. Our results implicate HDAC activity as a transcriptional mechanism that operates across cell types to regulate the alternative expression of genes that associate with regenerative success versus failure outcomes.

Effect of Thyroid-Stimulating Hormone Suppression on Muscle Function After Total Thyroidectomy in Patients With Thyroid Cancer

ContextThyroid-stimulating hormone (TSH) suppression is recommended to reduce tumor recurrence following surgery for differentiated thyroid cancer (DTC). However, prolonged subclinical hyperthyroidism caused by levothyroxine treatment has deleterious effects on various organs.ObjectiveTo evaluate the relationships of TSH concentration with muscle mass, muscle strength, and physical performance related to sarcopenia in patients with DTC undergoing TSH suppression following surgery.MethodsWe studied 134 patients of >60 years who were undergoing TSH suppression therapy following surgery for DTC. We evaluated muscle mass and muscle function-related parameters and diagnosed sarcopenia using the threshold for Asian people.ResultsThe participants were 68.3 ± 7.2 years old and 36/134 (26.9%) were diagnosed with sarcopenia. They were allocated to high-TSH and low-TSH groups using a threshold concentration of 0.40 μU/mL, and grip strength was significantly lower in the low-TSH group. The data were further analyzed according to age and sex, and in the low-TSH group, male participants and those of <70 years were found to have significantly lower grip strength.ConclusionsLow-TSH concentrations is associated with low grip strength, and this is most pronounced in individuals of <70 years of age. Therefore, muscle function should be considered an adverse effect of TSH suppression in patients with DTC who undergo TSH suppression therapy, especially in men of <70 years.

About the threshold concentration of nickel oxide nanoparticles in long-term inhalation exposure of rats

Introduction. Nickel oxide nanoparticles are of interest for toxicological science, not only as engineered nanoparticles, producing for industrial and scientific needs, but also as spontaneous pollutants of the atmosphere and the working area in industrial processes related to metallurgy and welding. Materials and methods. Rats were exposed to nickel-oxide aerosol at a concentration of 2.4 ± 0.4 µg/m3 in a “nose only” inhalation setup for 4 hours at a time, 5 times a week, during an overall period of 2 weeks to 6 months. Results. Of the several dozen examined parameters, only a few statistically significant manifestations associated with the reaction of the deep airways to inhaled nanoparticles were noted. However, in the biochemical and morphometric parameters of the lungs, even at the longest periods of exposure, the intergroup differences were insignificant. At the same time, even from the first weeks of the exposure period, genotoxic and allergic indices shifts are detected. Conclusion. For most of the evaluated effects, this level of exposure to nickel oxide nanoparticles may be considered as close to LOAEL, or even to NOAEL. However, according to some indicators, there are effects that suggest a non-threshold nature.

Rapid Algae Identification and Concentration Prediction Based on Discrete Excitation Fluorescence Spectra

In this paper, an algal identification and concentration determination method based on discrete excitation fluorescence spectra is proposed for online algae identification and concentration prediction. The discrete excitation fluorescence spectra of eight species of harmful algae from four algal categories were assessed. After determining typical excitation wavelengths according to the distribution of photosynthetic pigments and eliminating strongly correlated wavelengths by applying the hierarchical clustering, seven characteristic excitation wavelengths (405, 435, 470, 490, 535, 555, and 590 nm) were selected. By adding the ratios between feature points (435 and 470 nm, 470 and 490 nm, as well as 535 and 555 nm), standard feature spectra were established for classification. The classification accuracy in pure samples exceeded 95%, and that of dominant algae species in a mixed sample was 77.4%. Prediction of algae concentration was achieved by establishing linear regression models between fluorescence intensity at seven characteristic excitation wavelengths and concentrations. All models performed better at low concentrations, not exceeding the threshold concentration of red tide algae outbreak, which provides a proximate cell density of dominant algal species.

Influence of Formate Concentration on the Rheology and Thermal Degradation of Xanthan Gum

Xanthan gum solutions have gained increasing interest for their use as environmentally friendly chemicals in the oil industry. Xanthan is compatible with most concentrate brines used for controlling formation damage and fluid loss. Particularly, formate brines reinforce the ordered structure of the biopolymer in solution, gel strength, and the specific gravity of the resulting fluid. In this paper, we studied the effect of thermal aging on the rheological behavior of xanthan solutions as a function of the concentration in potassium formate. Ionic strength below a threshold concentration does not prevent the degradation of the structure of xanthan after being submitted to aging at 165 °C. Aged solutions show an important loss of strength in their mechanical properties, lower pH, and higher content in furfural and hydroxymethylfurfural. Highly concentrated formate brines are necessary to maintain the strength of the rheological properties after exposure to high-temperature environments.

On the creation of databases to assess the impact of chemicals on the organoleptic and general sanitary limiting signs of the harmfulness in the water of water bodies

Introduction. Information on the MPC (TAC) value and the limiting hazard sign is important for the analysis of the hazard of chemicals in the water of water bodies for the health of the population, serves as the basis for the development of preventive measures to ensure safe conditions for water use by the population. For the purpose of specifying the possible adverse effects of the influence of chemicals on the hygienic conditions of water use of the population, information is needed on the entire spectrum of the effects of chemicals on water quality indicators. Materials and methods. The object of the study was indicators characterizing the effect of chemicals on the organoleptic properties of water and the general sanitary regime of water bodies, algorithms for analyzing primary data to determine threshold concentrations for the effect on odor, color, turbidity, foaming, pH, general sanitary regime of water bodies - biochemical oxygen consumption, concentration of nitrogenous connections. To organize the databases, the standard apparatus of the Excel subBD electronic tables was used. The mathematical apparatus of data analysis, grouping and selection of critical indicators of limiting signs is presented. Conclusion. It is concluded that the use of databases allows to study the relationship “concentration - effect”, increases the reliability and accuracy of substantiating the threshold concentration of pollutants in water by the influence of limiting signs of harmfulness.

Presence and concentration of polycyclic aromatic hydrocarbons (PAHs) in sediments and organisms from Tampamachoco coastal lagoon and Tuxpan River, Veracruz; México.

Polycyclic aromatic hydrocarbons (PAHs) have carcinogenic and mutagenic properties and their main origin in the environment is the burning of fossil fuels and organic material and they are considered high priority Persistent Organic Compounds (POPs). In the present study (March and August 2018) the concentrations of the 16 priority PAHs were analyzed in sediments and organisms (fish and oysters) in the estuarine-lagoon system Tuxpan-Tampamachoco, Veracruz; Mexico.The analysis of these compounds was carried out by means of gas chromatography-FID and mass spectrometry. In March (dry season) the average concentration of PAHs in sediments was 0.86 ± 0.39 μg/g and in August (rainy season) it was 1.14 ± 0.45 μg/g. During both collections, chrysene presented the highest total concentrations and a domain of the compounds with 4 benzene rings was observed, therefore, pyrolytic sources of contribution predominated. The highest concentrations of PAHs occurred in 2 stations located in the Tuxpan riverbed and both exceeded the threshold concentration to cause adverse effects to the benthic community.The analysis of PAHs in organism tissues was carried out in 4 species of fish and one mollusk. In march, the species with the highest concentration was Bagre marinus with 88.87 μg/g and in august it corresponded to the Caranx hippos species with 26.82 μg/g and the compound determined with the highest presence was benzo(b)fluoranthene.Finally, the tendency of accumulation of PAHs in the evaluated matrices was: fish> sediments> mollusks.

Threshold concentration and random collision determine the growth of the huntingtin inclusion from a stable core

The processes underlying formation and growth of unfolded protein inclusions are relevant to neurodegenerative diseases but poorly characterized in living cells. In S. cerevisiae, inclusions formed by mutant huntingtin (mHtt) have some characteristics of biomolecular condensates but the physical nature and growth mechanisms of inclusion bodies remain unclear. We have probed the relationship between concentration and inclusion growth in vivo and find that growth of mHtt inclusions in living cells is triggered at a cytoplasmic threshold concentration, while reduction in cytoplasmic mHtt causes inclusions to shrink. The growth rate is consistent with incorporation of new material through collision and coalescence. A small remnant of the inclusion is relatively long-lasting, suggesting that it contains a core that is structurally distinct, and which may serve to nucleate it. These observations support a model in which aggregative particles are incorporated by random collision into a phase-separated condensate composed of a particle-rich mixture.