Exposure Time Research Articles

The Association of Outdoor Temperature with Severe Hyponatremia: A Study Based on the Stockholm Sodium Cohort.

Hyponatremia is a common condition with unspecific symptoms and a complicated etiology. The impact of outdoor temperature on hyponatremia is not well-studied and varies depending on the climate and location. This study aimed to investigate the association between outdoor temperature and the prevalence of severe hyponatremia. This retrospective register-based cohort study based on the Stockholm Sodium Cohort investigated the association between ambient temperatures and severe hyponatremia (<125 mmol/L) in adults. Prevalence rates of severe hyponatremia were calculated as the number of days of severe hyponatremia divided by person-days at risk for the same temperature, using mean daily temperatures at the area of residence of each study participant to calculate exposure time. A prediction model incorporating changes in demographics and climate was used to estimate the burden of severe hyponatremia in Stockholm by 2050. We identified 51,143 episodes of severe hyponatremia in 21,924 adults. A near linear modest increase in prevalence with rising temperatures was observed up to 20°C, followed by rapidly increasing rates at higher temperatures. The prevalence was higher with older age, reaching >100 days of hyponatremia per million person-days among +80-years-olds at temperatures over 22°C. Women experienced twice the rate observed in men. Temperature rises of 1°C or 2°C by the year 2050 are expected to be associated with higher prevalence rates by 66% and 73%, respectively. There was a strong association between high temperatures and severe hyponatremia. The higher prevalence of severe hyponatremia was most pronounced among elderly.

What do trees reveal about the sliding of the lateral moraine of the Belvedere Glacier (western Italian Alps)?

The debris-covered Belvedere Glacier is an iconic place for investigating glacier dynamics and geomorphological processes typical of high mountain environments. Moreover, being located in an area highly suited to tourism, glacial and geomorphological hazards can evolve into risk scenarios. Particular attention has been paid during this research to the surge-type event that occurred at the beginning of the 21st century, and to the recent sliding of a lateral moraine nearby the chairlift station. Tree sampling was performed (19 trees on the lateral moraine; 10 undisturbed trees), and the results were compared with morphometric measurements on orthophotos of different years. Besides sampling trunks, the six available exposed roots (13 samples) from a tree located along the sliding niche were sampled to identify the exposure time. Morphometric measurements of the touristic trail dislocation indicate a sliding rate of 1.87 m/y – 1.98 m/y (2018–2023), while the regression rate of the sliding niche is 1.70 m/y (2021–2023). The age of trees along the trench is variable (14–49 years), as is the signal of compression wood, enhancing differentially the passage of the surge wave and the subsequent glacier downwasting. The beginning of root exposure occurred between 2017 and 2019, before the effective evidence of large fractures in the ground. Moreover, the roots show traumatic resin ducts in the period between 2020 and 2022, confirming the tree disturbance. In conclusion, the investigated events are recorded differentially in the sampled trees, especially in roots, anticipating the actual commencement of ground failure. A multidisciplinary approach, including remote sensing, field survey, and dendrogeomorphological analysis is essential to define the dynamics of complex systems.

Reducing Laser Exposure Time of PBF-LB/P by Providing High Energy Without Thermal Degradation and Its Effect on Part Strength and Process Time

Abstract One of the most promising additive manufacturing technologies for the production of end-use parts is powder bed fusion of polymer with laser beam (PBF-LB/P). This technology can reduce production costs by increasing process efficiency and production speed. As PBF-LB/P is a layer-wise additive manufacturing process, the production speed can be increased by reducing the layering time. Although some operations such as recoating are performed during the layering process, considerable time is spent on laser scanning. To reduce the laser exposure time while maintaining proper powder melting, a high-power beam should be irradiated to the powder layer to prevent energy shortage. However, as the laser beam power increases, the irradiance at the beam center increases significantly, causing powder degradation such as thermal decomposition or sublimation. In this study, an appropriate input energy range was determined by obtaining an input energy limit that does not cause powder deterioration via experimental observations and temperature estimations during the process. Furthermore, the influence of the scanning parameters on the mechanical properties of built specimens was investigated to reduce the layering time within an indicated range. Results show that the mechanical strength of the built parts decreases slightly as the scan spacing increases following the expansion of the beam diameter. This study also validated the effects of scanning parameters on layering time. As a result, by doubling the scan speed and spacing, the layering time can be reduced by up to 1/3.

Role of extractives on the weathering of tropical and temperate wood species in two above-ground fields: coastal or terrestrial

The effect of heartwood extractives on natural weathering of 5 temperate (juniper, walnut, oak, pseudoacacia, and chestnut) and 9 tropical (wenge, teak, iroko, dahoma, moabi, okan, padauk, ipe, and tatajuba) wood species against abiotic degrading agents at two sites was investigated. Wood species were exposed to three-stage extraction, then extracted and un-extracted samples were exposed outdoors for 12 months in two above-ground test sites, coastal or terrestrial. Samples were evaluated regarding moisture content, color change, surface roughness, and surface chemistry (ATR-FTIR) at 1, 3, 6, and 12 months of exposure. Results indicate that roughness and color change increased as the exposure time increased. Among the temperate species, the least rough surfaces were found in juniper, while iroko, ipe, and wenge were for tropical species. The location did not statistically affect roughness. Temperate species generally showed rougher surfaces than tropical species. The remarkable color change occurred in the first 3 months in temperate wood species and between 3 and 6 months in extractive-rich tropical wood species. The highest color change was seen in samples extracted and exposed on the terrestrial test site, while the lowest was in un-extracted samples exposed on the coast. Padauk had the most color change, while moabi had the least. The surfaces of temperate species showed darkening while the surfaces of tropical species showed lightening during the weathering exposure. FTIR studies confirmed that the change in the surface chemistry of temperate species mostly occurs in the first month, while surface degradation of some tropical species can take up to 3 months.

Machine Learning Models for Predicting Bioavailability of Traditional and Emerging Aromatic Contaminants in Plant Roots.

To predict the behavior of aromatic contaminants (ACs) in complex soil-plant systems, this study developed machine learning (ML) models to estimate the root concentration factor (RCF) of both traditional (e.g., polycyclic aromatic hydrocarbons, polychlorinated biphenyls) and emerging ACs (e.g., phthalate acid esters, aryl organophosphate esters). Four ML algorithms were employed, trained on a unified RCF dataset comprising 878 data points, covering 6 features of soil-plant cultivation systems and 98 molecular descriptors of 55 chemicals, including 29 emerging ACs. The gradient-boosted regression tree (GBRT) model demonstrated strong predictive performance, with a coefficient of determination (R2) of 0.75, a mean absolute error (MAE) of 0.11, and a root mean square error (RMSE) of 0.22, as validated by five-fold cross-validation. Multiple explanatory analyses highlighted the significance of soil organic matter (SOM), plant protein and lipid content, exposure time, and molecular descriptors related to electronegativity distribution pattern (GATS8e) and double-ring structure (fr_bicyclic). An increase in SOM was found to decrease the overall RCF, while other variables showed strong correlations within specific ranges. This GBRT model provides an important tool for assessing the environmental behaviors of ACs in soil-plant systems, thereby supporting further investigations into their ecological and human exposure risks.

Physicochemical properties, structure and biological activity of ginger polysaccharide: Effect of microwave infrared dual-field coupled drying

Ginger was dried by microwave infrared dual-field coupled drying (MIDFCD). The composition, structure, physicochemical properties and biological activity of ginger polysaccharides at various stages of MIDFCD were investigated. The MIDFCD significantly impacted the chemical composition, molecular weight (Mw), microstructure, and physicochemical properties of ginger polysaccharides. However, there were no notable differences in functional group composition. The Mw and chemical composition were notably influenced by microwave-infrared exposure and prolonged drying time. The degradation of polysaccharides due to high temperatures in the later stage resulted in further decreases in Mw and alterations in monosaccharide composition. These changes in chemical composition and Mw affected thermal properties, crystallization properties, particle size, rheological properties, antioxidant capacity, and hypoglycemic activity. These findings suggest that MIDFCD enhances the quality and bioactivity of natural polysaccharides. This study offers theoretical support for MIDFCD processing and the value-added utilization of ginger.

The Impact of Radiofrequency Electromagnetic Waves on DNA Fragmentation Index and Spermatogenesis-related Genes Expression in Rats

Background: We aimed to evaluate the impact of radiofrequency electromagnetic waves (RF-EMW) with wavelengths equivalent to mobile phones on semen parameters and expression levels of spermatogenesis-related genes in rats. Methods: A total of 20 male adult Wistar rats weighing approximately 180 g were randomly allocated to two study groups in this controlled, parallel-design study. The case group was exposed to RF-EMW. The gene’s expression was assessed by real-time PCR for five target genes: ZBTB16, SCP3, ACR, ITGA6, and PRM1. Results: The DNA fragmentation index (DFI) assessment reveals a significant difference between the cases and the control group. There was a two-fold increase in ACR gene expression than in the RF-EMW exposure group. The contradictory result was seen in the other four genes, which showed that gene expression decreased to about 0.3 for PRM1 and SCP3, 0.5 for ITGA6, and 0.7 for ZBTB16. Sperm motility was not significantly different between the two groups, but morphology in the case group revealed higher abnormalities than in the control group. Conclusion: We recommend reducing exposure time to radiofrequency waves, and keeping cell phones away from our bodies as far as possible is safer. Additional studies are required to support our data.

Selenium nanoparticles stabilized with chitosan for fortifying dairy products

Relevance. One solution to the problem of selenium deficiency is the enrichment of socially important food products, in particular dairy products, with bioavailable forms of selenium. Such forms include selenium nanoparticles. The aim of the work is to develop a dairy product enriched with selenium nanoparticles stabilized with chitosan.Methods. According to dynamic light scattering spectroscopy, a sample of selenium nanoparticles stabilized with chitosan has a monomodal size distribution with an average hydrodynamic particle radius of 25 nm.Results. Quantum chemical modeling of selenium nanoparticles stabilized by chitosan has revealed that the most energetically favorable interaction is the interaction of the surface of selenium nanoparticles with the hydroxo group attached to the C3 glucosamine residue of chitosan. A study was conducted of the influence of technological parameters on the stability of selenium nanoparticles stabilized with chitosan. It was found that increasing the exposure time leads to an increase in the average hydrodynamic radius of selenium nanoparticles stabilized by chitosan. In the case of pH, an inverse relationship is observed: particles with the largest average hydrodynamic radius are found in samples with an acidic environment (pH ˂ 5). As part of a study of the influence of technological parameters on the stability of selenium nanoparticles stabilized by chitosan, it was found that selenium nanoparticles stabilized by chitosan can be used as a source of selenium for food products that have a neutral pH, but can be subjected to heat treatment at temperatures above 70 °C in for 5–15 minutes, in particular pasteurized milk. A study of pasteurized milk fortified with selenium nanoparticles stabilized by chitosan showed that there were no significant changes in titratable acidity, surface tension and pH of milk, as well as the average hydrodynamic radius of casein micelles after milk fortification. The value of antioxidant activity increases by 0.88% — from 6.50 to 7.38%.

Corrosion Behavior of 700L Automotive Beam Steel in Marine Atmospheric Environment.

The marine atmospheric corrosion behavior of 700L high-strength automotive beam steel exposed for 36 months was investigated by scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, and electrochemical technology. The corrosion kinetics of 700L steel followed the exponential function: D = 4.85t1.23. The rust layers were mainly composited of γ-FeOOH, α-FeOOH, γ-Fe2O3, and Fe3O4, regardless of the exposure duration. With an extended exposure time, the porosity, cracking, and spalling of the rust layers increased, and the densification and thickness uniformity decreased. Electrochemical measurements displayed that the corrosion resistance of the rusted 700L steel gradually decreased with increasing exposure time. A good correlation was found between rust layer composition, microstructure, and corrosion resistance.

Numerical simulation of the creep of a turbine blade made of a monocrystalline alloy

The article is devoted to the creep model of a monocrystalline alloy and the development of a methodology for identifying material parameters based on the results of physical experiments. A finite element analysis of the creep of a gas turbine engine blade was performed. Creep is one of the most dangerous types of deformation in the operating conditions of turbine blades. In the process of studying the problems of assessing the strength of turbine blades of aircraft engines and power plants, special attention should be paid to the study of stress redistribution during creep. The characteristics of the crystallographic structures of modern turbine blades have a very significant influence on the progress of the crack development process during engine operation. To date, turbine blades are manufactured by the method of single-crystal casting. This type of blade material structure is characterized by orthotropic mechanical properties. This study considers the steady-state creep model of an anisotropic heat-resistant single-crystal alloy with cubic symmetry. The authors carried out a numerical simulation of the material parameters using the well-known literary creep properties of single crystals. An algorithm is described that allows you to determine some creep characteristics of single crystals. The parameters of the given ratios can be obtained after conducting direct experiments, or based on micromechanical analysis, using the example of composite materials. The authors calculated the creep constants of a typical heat-resistant monocrystalline alloy as a result of the approximation of its creep curves, which were obtained experimentally. Based on the Norton-Bailey equation and using the Maple Release 2021.0 calculation complex, a graph of the dependence of the rate of creep deformation on the level of load applied to the material was plotted, and the minimum rate of deformation and creep constants were also determined. The results of the calculations were used for finite-element simulation of creep on the example of a solid-state model of a high-pressure turbine blade. Several series of calculations were carried out on the basis of the ANSYS Workbench complex, in particular, the calculation of the elastic problem when the blade is loaded by centrifugal forces, as well as the accumulation of creep deformations at different exposure times. Graphs of the change in equivalent stresses and creep deformations as a function of time are plotted.

Enhancing Intrapleural Hyperthermic Chemotherapy for Lung Cancer: Insights from 3D and PDX Models

Background/Objectives: Malignant pleural effusion (MPE) in lung cancer indicates systemically disseminated advanced lung cancer and is associated with poor survival. Intrapleural hyperthermic chemotherapy (IPHC) is a promising treatment for MPE; however, its biological basis is not fully understood. IPHC can enhance anticancer drug efficacy, particularly in drug-resistant cancers. This study investigated the effects of hyperthermia on cisplatin cytotoxicity in lung cancer cell lines, patient-derived tumor cells, and a patient-derived xenograft (PDX) model. Methods: Lung cancer cell lines (A549 and H2170) and patient-derived tumor cells were cultured in 2D/3D systems and treated with cisplatin under varying temperatures (37 °C, 43 °C, and 45 °C) and exposure times (5, 15, and 30 min). Antiproliferative effects were evaluated using LDH and CCK-8 assays. Optimal conditions identified in cell culture experiments were validated using a PDX model; tumor growth inhibition, delay, and protein expression were analyzed post-treatment. Results: Hyperthermia significantly enhanced the antitumor efficacy of cisplatin at 43 °C and 45 °C, with comparable effects under 15 and 30 min exposure. In the PDX model, IPHC showed increased tumor inhibition and necrosis and delayed tumor regrowth, particularly at higher cisplatin doses. Protein expression analysis revealed that hyperthermia decreased EGFR expression and increased levels of apoptosis-related proteins, including cleaved PARP and caspase-3. Conclusions: IPHC with cisplatin demonstrated enhanced antitumor efficacy in vitro models, particularly in drug-resistant lung cancer, indicating its potential as a valuable adjunct to existing treatment regimens for lung cancer and for improving patient outcomes in advanced lung cancer with MPE or pleural metastasis.

Recent trends and disparities in screen-based sedentary behavior and physical activity among U.S. overweight youth, 2018–2022

BackgroundSedentary behavior (SB) and physical activity (PA) are crucial factors influencing health outcomes in overweight children and adolescents. However, recent changes in SB and PA trends among U.S. overweight youth have not been well described, limiting the development of evidence-based clinical and public health interventions. MethodsSerial, cross-sectional analyses were conducted using data from the National Survey of Children's Health (NSCH) on U.S. overweight youth aged 6–17 years, spanning from 2018 to 2022. Linear regression models were employed to analyze time trends, with survey year as the exposure and recreational screen time (ST), adherence to the ≤2 h/day ST guideline, and adherence to the ≥1 h/day PA guideline as the outcomes. Multivariable-adjusted logistic and linear regressions were used to evaluate trends, adjusting for age group, sex, race/ethnicity, household income, and the highest education level of primary caregivers. ResultsData from 11,865 individuals (mean age 12.3 years [SD 2.9]; 6417 [52.3 %] girls) were analyzed. From 2018 to 2022, the average ST duration among overweight youth increased from 3.7 h to 4.1 h per day, a statistically significant increase (p = 0.07). The estimated prevalence of overweight youth meeting the ≤2 h/day ST guideline decreased from 44.6 % to 30.0 % (p = 0.007). Additionally, the prevalence of meeting the ≥1 h/day PA guideline remained low and stable, ranging from 8.4 % to 12.3 % during the analysis period (p = 0.6). DiscussionIn this nationally representative sample of U.S. overweight youth, ST increased by nearly 0.4 h/day over the five-year observation period, while adherence to the ≤2 h/day ST guideline decreased. Adherence to the ≥1 h/day PA guideline remained consistently low. These patterns were consistent across sociodemographic subgroups (age group, sex, ethnicity, and household income). These findings underscore the need for enhanced public health initiatives targeting U.S. youth to reduce recreational screen time and promote a physically active lifestyle.

Investigation of the Effect of High Shear Stress on Mesenchymal Stem Cells Using a Rotational Rheometer in a Small-Angle Cone-Plate Configuration.

Within the healthy human body, cells reside within the physiological environment of a tissue compound. Here, they are subject to constant low levels of mechanical stress that can influence the growth and differentiation of the cells. The liposuction of adipose tissue and the subsequent isolation of mesenchymal stem/stromal cells (MSCs), for example, are procedures that induce a high level of mechanical shear stress. As MSCs play a central role in tissue regeneration by migrating into regenerating areas and driving regeneration through proliferation and tissue-specific differentiation, they are increasingly used in therapeutic applications. Consequently, there is a strong interest in investigating the effects of shear stress on MSCs. In this study, we present a set-up for applying high shear rates to cells based on a rotational rheometer with a small-angle cone-plate configuration. This set-up was used to investigate the effect of various shear stresses on human adipose-derived MSCs in suspension. The results of the study show that the viability of the cells remained unaffected up to 18.38 Pa for an exposure time of 5 min. However, it was observed that intense shear stress damaged the cells, with longer treatment durations increasing the percentage of cell debris.

Effect of Heat Treatment on Corrosion Behavior of S275 Mild Steel Using Accelerated DC Voltage, LPR, and EIS

AbstractThis study used an external DC voltage of 1.5 V to accelerate corrosion in heat-treated S275 mild steel samples at different time intervals. LPR and EIS were used to study the corrosion behavior of original and quenched steel samples. There was only a negligible difference in the corrosion rate (CR) for the original and the quenched samples up to 30 min of voltage application in a 3.5% NaCl electrolyte media. When the exposure time increased to 60 min, the original sample showed seven times higher CR than the quenched samples. The pits on the surface of the original samples acted as cathodes, enhancing the reaction rate on the surface and increasing its CR dramatically. This led to bimodal corrosion, where the first part is led by concentration and diffusion; while, the second part is led by localized corrosion. The smaller pits on the original surface samples served as cathodic reaction centers, exacerbating corrosion. The corrosion rate of the original samples ranged from 0.8 to 7.8 mmpy; whereas, the corrosion rate of the quenched samples remained consistently around 0.8 mmpy. This trend can be observed in long-term corrosion in different metals. The uniformly oriented martensitic microstructure and the quenched samples’ small grain size prevented the enhanced ion penetration due to applied voltage. This study analyses the long-term stability of structural steel samples in marine environments by accelerating the corrosion rate by an applied external DC voltage.

A study on bacterial inactivation using green synthesized photocatalytically active TiO2, MgO, TiO2/MgO nanoparticles

Madhuca longifolia (Mahua) flower extracts were utilised to perform the green synthesis of titanium dioxide (TiO2), magnesium oxide (MgO) nanoparticles, and a nanocomposite consisting of TiO2/MgO. Mahua flower extracts were used as both reducing and capping agents in a sol-gel synthesis method. The effectiveness of the green reducing agent in improving the surface structure of the green nanoparticles was demonstrated. FTIR, XRD, FESEM, and UV vis spectroscopy were employed to analyse the successful synthesis of TiO2, MgO, and TiO2/MgO nanocomposites. A study was done to examine the process of employing these nanoparticles to deactivate Escherichia coli (E. coli) by photocatalysis. The effectiveness of these nanoparticles in inhibiting the growth of the bacterial species was demonstrated. The optimisation of the bacterial inactivation experiment was performed using Design Expert's RSM CCD model on all three nanoparticle samples. The optimisation study investigated the impact of nanoparticle concentration and exposure duration on the inhibition of bacterial growth. The highest levels of percent inhibition (%I) were recorded as 85.4 % for TiO2/MgO, 82.8 % for TiO2, and 65.14 % for MgO at a concentration of 50 mg/2 ml and an exposure time of 2 h. The effectiveness of these nanoparticles in exhibiting inhibition has been limited, indicating their prospective use in the advancement of antimicrobial coatings and other applications, such as disinfectants, in the future.

Optimizing PES microfiltration membranes for sterile filtration: A comparative study of polydopamine coating in acidic and basic conditions to minimize protein adsorption

The increasing need for effective sterile filtration in the pharmaceutical industry calls for advancements in microfiltration (MF) membrane technology that can effectively reduce fouling and preserve essential protein products. Our study highlights the crucial role of improving the hydrophilicity throughout the entire membrane, not just on the surface, to decrease both protein adsorption and fouling. We have developed a facile but effective method for producing hydrophilic porous polyethersulfone (PES) MF membranes using vapor-induced phase separation (VIPS) followed by a hydrophilic coating. By meticulously adjusting the vapor exposure time, we fabricated two specific types of symmetric membranes: a standard one with a mean pore size of 0.22 μm and another designed with slightly larger pores for the subsequent polydopamine (PDA) coating. All membranes developed in this study showed an outstanding sterilization performance (over 99.99999 % bacteria rejection) due to the absence of defects. Our comparative studies of PDA coating in both acidic and basic environments revealed that the PDA-modified membranes in a Tris-HCl buffer (pH 8.0) (PDA-b-PES2M) outperform others in performance of protein microfiltration. While the membrane modified under acidic conditions underwent a gradual degradation of PDA leading to a poor filtration performance, the PDA-b-PES2M membranes showcased remarkable anti-fouling properties, greatly minimizing the adsorption of bovine serum albumin (BSA) and simplifying the removal of adsorbed materials. Our optimized membrane has a great potential for sterile filtration applications where minimizing protein loss is crucial.

Exposure effects of synthetic glucocorticoid drugs on skeletal developmental and immune cell function in zebrafish

Synthetic glucocorticoids (GCs) are used to treat a wide range of human health conditions and as such are frequently detected in the aquatic environment. This, together with the highly conserved nature of the glucocorticoid system across vertebrates means that the potential for biological effects of GCs in fish is relatively high. Here, we found that exposure of zebrafish (Danio rerio) to environmentally relevant concentrations of 4 of the most widely used synthetic GCs (beclomethasone dipropionate, budesonide, fluticasone propionate, and prednisolone), from 0 to 4 days post fertilisation (dpf), resulted in no effects on embryo-larval development or bone and cartilage formation. However, after exposure to equivalents of human therapeutic plasma levels, developmental abnormalities were observed that included pericardial oedema, blood pooling and alterations in jaw cartilage. Furthermore, using a double transgenic zebrafish osteoblast and chondrocyte reporter line, exposure up to 10 dpf resulted in alterations to lower jaw cartilage and bone development for all compounds at, and above, human therapeutic plasma concentrations. In the case of beclomethasone dipropionate, a reduction in lower jaw intercranial distance was observed at the environmentally relevant concentration of 0.1 μg/L. Using further transgenic reporter lines with fluorescently tagged neutrophils and macrophages, we also show exposure of embryo-larvae (0–4 dpf) to the GCs tested resulted in altered immune cell migration, but only at relatively high exposure concentrations. Collectively, our findings show GC exposure impacts embryo-larval zebrafish development, immune function, and skeletal formation, but predominantly at concentrations greater than those currently reported for the aquatic environment. Despite this, however, it is suggested that studies with longer exposure times, and to mixtures of multiple GCs (many GCs act via the same mechanism of action) are warranted before we can confidently assert that these commonly detected contaminants do not pose a risk to fish in the wild.

Antiproliferative Effects of Naja anchietae and Naja senegalensis Venom Peptides on Glioblastoma Cell Lines.

This study explores the potential of natural bioactive peptides from animal venoms as targeted anti-cancer agents with reduced toxicity. Initially, we screened a broad collection of animal venoms for their antiproliferative activity against cancer cell lines. From this collection, we selected venoms from Naja anchietae and Naja senegalensis due to their promising activity. Utilizing reverse- phase high-performance liquid chromatography (RP HPLC), mass spectrometry (MALDI-TOF MS and MALDI-TOF TOF MSMS), and Edman degradation sequencing, we isolated and characterized three peptides named CTNanc1, CTNanc2, and CTNanc3 from Naja anchietae, and three others named CTNsen1, CTNsen2, and CTNsen3 from Naja senegalensis, each with a molecular weight of around 7 kDa. These purified peptides demonstrated inhibition of U87 glioblastoma cell proliferation, but not of U251 and T98G cells, in cell viability assays. To assess the impact of these treatments on cell viability, apoptosis, and necrosis, flow cytometry assays were conducted on U87 cells at 72 h. The results showed a decrease in cell viability and an increase in dead cells, suggesting that the treatments not only promote apoptosis, but may also lead to increased necrosis or late-stage apoptosis as the exposure time increases. These findings suggest that these peptides could be developed as leads for cancer therapy.

Restorative and endodontic clinical strategies during COVID-19 (SARS-CoV-2) pandemic: a revision of the literature.

The aim of this study was to analyze clinical strategies supported by validated references during two of the most frequent dental emergencies (i.e. restorative and endodontic treatment) in the COVID-19 pandemic. Coronavirus disease 2019 (COVID-19) was caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of an emergency in the health system worldwide and a potentially fatal disease. Person-to-person transmission of SARS-CoV-2 through aerosol and droplets led to extensive preventive measures to contain COVID-19 outbreak. Dental care providers have been exposed to a high risk of SARS-CoV-2 infection, due to the face-to-face communication and the exposure to saliva, blood, and other body fluids during routine interventions; this can also contribute to a high risk for cross-infection, even though dentist usually cope with those situations in everyday practice. Restorative and endodontic emergencies represented a high proportion of dental emergencies, with prolonged exposure time for dentists/endodontists in contact with suspected or confirmed infected patients. Lack of knowledge and undefined progression controlled the decision-making in clinical dentistry. The dynamicity of the situation determined change of views and recommendations in dental setting. The implementation of strict restorative and endodontics protocols are aimed at preventing circumstances similar to those observed with COVID-19.

Serosurvey of Leptospira spp. in captive non-human primates in Spain

Leptospirosis is a worldwide zoonotic disease caused by serovars of Leptospira spp. that can infect a wide range of wild and domestic species, highlighting non-human primates (NHPs) as one of the most susceptible taxonomic groups. The aim of the present study was to determine the seroprevalence and potential risk factors associated with exposure to Leptospira spp. in captive NHPs in Spain. Between 2007 and 2021, sera were collected from 258 NHPs in 16 zoos and wildlife rescue centers (WRCs), and tested for antibodies to Leptospira spp. using the modified microagglutination test (MAT). Anti-Leptospira spp. antibodies were detected in 73 (28.3 %) of the 258 NHPs evaluated. Seropositivity was found in 61.0 % (25/41) of the species analyzed and in 87.5 % (14/16) of the sampled centers. Sera seropositive for six different serovars of Leptospira spp. were detected, with L. Grippotyphosa being the most prevalent. Seroprevalence was found to be significantly higher in Hominidae (61.8 %; P < 0.001) compared to other NHP families tested. To the author’s knowledge, the present study is the largest serosurvey of Leptospira spp. conducted in NHPs in Europe and also reports for the first time exposure to Leptospira spp. in nine NHP species, expanding the host range for this zoonotic bacterium. Our results indicate high and widespread seropositivity of Leptospira spp. in NHPs kept in captivity in Spain, which may be of conservation and animal health concern. This study supports the need to include captive NHPs in monitoring programs to evaluate the exposure of these species to Leptospira spp. in captive centers.