Hours Of Exposure Research Articles

Zeolite Synthesis from Natural Kaolin: The Effect of Metakaolin Heating and Transformation

In this study, the effect of kaolin heating and metakaolin transformation on zeolite synthesis was investigated. Two different metakaolin temperatures at the early stage of transformation were chosen in determining the lowest temperature that was capable of synthesizing the zeolite structure from natural kaolin. The synthesis of zeolite materials from the transformation of natural kaolin to metakoalin was conducted through the hydrothermal method. Natural kaolin obtained from Ipoh, Perak, was calcined at two different calcination temperatures of 600°C and 650°C. Metakaolin was obtained after 2 hours of exposure at 600°C and 650°C, respectively, with slightly different FTIR peaks of quartz at both temperatures. The incomplete metakaolin formation at a slightly lower temperature revealed the unsuccessful zeolite formation. At slightly higher calcination temperatures, the metakoalin peak obviously existed and led to the formation of the complete zeolite phase.This experiment also proved the importance of accurate calcination temperature in converting to zeolite synthesis. Furthermore, this current work also revealed that the complete transformation of metakoalin that can be conducted slightly lower temperature as compared to the common metakoalin phase will minimize energy consumption during the zeolite synthesis as well as the metakoalin transformation.

PKA Activity-Driven Modulation of Bidirectional Long-Distance transport of Lysosomal vesicles During Synapse Maintenance.

The bidirectional long-distance transport of organelles is crucial for cell body-synapse communication. However, the mechanisms by which this transport is modulated for synapse formation, maintenance, and plasticity are not fully understood. Here, we demonstrate through quantitative analyses that maintaining sensory neuron-motor neuron synapses in the Aplysia gill-siphon withdrawal reflex is linked to a sustained reduction in the retrograde transport of lysosomal vesicles in sensory neurons. Interestingly, while mitochondrial transport in the anterograde direction increases within 12 hours of synapse formation, the reduction in lysosomal vesicle retrograde transport appears three days after synapse formation. Moreover, we find that formation of new synapses during learning induced by neuromodulatory neurotransmitter serotonin further reduces lysosomal vesicle transport within 24 hours, whereas mitochondrial transport increases in the anterograde direction within one hour of exposure. Pharmacological inhibition of several signaling pathways pinpoints PKA as a key regulator of retrograde transport of lysosomal vesicles during synapse maintenance. These results demonstrate that synapse formation leads to organelle-specific and direction specific enduring changes in long-distance transport, offering insights into the mechanisms underlying synapse maintenance and plasticity.

Epidemiology of football-related injuries in young male football players. An additional analysis of data from a cluster-randomised controlled trial

ABSTRACT Football carries a high risk of injury for youth players. The aim of this study was to investigate the epidemiology of football-related injuries in young male players. The data stems from a previously conducted cluster-randomised controlled trial that investigated the efficacy of ‘FUNBALL’, a new injury prevention programme. This study contains the data of the 503 players of the control arm. The players belonged to 22 football teams of the Under-(U)15, U17 and U19 age groups. The time-loss injuries were recorded during the season 2021–2022 according to the Football Consensus Statement. An analysis on the injury incidence (IR, calculated per 1000 hours of exposure), location, severity, category, and type was performed. Incidence rate ratios (IRRs) were used to compare the variables between the specific age groups. 187 injuries (96 in training and 91 in matches) occurred during 52 938 hours of exposure. The overall IR was 3.53 injuries/1000 h (95% confidence intervals (CI) 3.06 to 4.07). The training IR was 2.16 injuries/1000 h (95% CI 1.17 to 2.64). The match IR was 10.50 injuries/1000 h (95% CI 8.55 to 12.89). In the U19s, the overall IRR was higher compared to the U17s (IRR 1.57, CI 1.12 to 2.19; p = 0.008) and compared to the U15s (IRR 1.82, 95% CI 1.25 to 2.62; p = 0.001). The thigh was the most commonly affected body region (IR 0.92/1000 h, 95% CI 0.69 to 1.22). Muscle injuries were the most common injury type (IR 1.05/1000 h, 95% CI 0.81 to 1.37). Injury burden was 74 lost days/1000 h. The findings of this study indicate a lower injury incidence in youth players than in adult ones. We observed a higher injury incidence towards the older age groups.

The Impact of a 4-Domain Wellness-Initiative Curriculum on Internal Medicine Resident Physicians.

There is a trend toward fostering well-being, or the state of being happy and healthy, within the medical community. Historically, resident physicians have faced high rates of distress during training. A structured well-being curriculum in residency programs may shift residents' mindsets from survival and resilience to one centered on purpose, engagement, and joy. An original well-being curriculum was administered to residents in person at a single institution every 5 weeks for approximately 10 well-being workshops, totaling around 20 hours of curriculum exposure during every academic year. The well-being curriculum was divided into 4 domains: cognitive distortions and problematic mindsets, mindfulness and meditation, creative outlets, and self-compassion.Residents exposed to at least 1 year of the well-being curriculum were asked to answer an anonymous survey. Four questions were asked for each of the 4 domains. The first and second questions asked how familiar they were with the topic before and after the workshops on a scale of 1-5 of familiarity. The third and fourth questions asked how much the knowledge acquired influenced their professional and personal life on a scale of 1-5 of influence. Before curriculum exposure, the average for moderate or higher levels of knowledge across all domains was 22.7%, which improved to 77.3% after curriculum completion. Overall, 58.6% of participants felt the knowledge of the domains was moderately or extremely influential in their professional lives and 83.6% in their personal lives. There were no significant differences between post-graduate year 2 and post-graduate year 3 residents for any domains examined before and after the wellness workshops. A 4-domain well-being curriculum practiced in a group setting positively impacted participating residents in their personal and professional lives. Further studies need to be performed on a larger scale to assess if the curriculum fits the needs of the broader medical community.

Electronic media exposure, parental language input, and child vocalizations in rural and peri-urban China

To examine the association between electronic media exposure and parental language input, Language Environment Analysis technology was used to collect data on electronic media exposure and parental language input in 158 peri-urban and rural households with children aged 18–24 months in southwestern China. The sounds children made and the sounds they heard were quantified. Multiple linear regression and quantile linear regression were used to determine the relationship between electronic media and the outcomes of interest. The results showed that each hour of electronic media exposure was associated with reduced conversational turn count (p < .05) and child vocalization count (p < .05). A large share of the reduction was driven by the higher quantile of children. Reductions associated with electronic exposure were also observed in number of segments and conversational turns. These results may help explain the association between child electronic media exposure and language delay in an under-studied and at-risk population.

Enhancing sulfide and methane control in sewers: Unveiling the impact and mechanisms of free nitrous acid pre-exposure coupled with calcium peroxide dosing

Although biocides have proven highly efficient in controlling hazardous emissions and mitigating organic carbon loss in sewers, the resistance of biofilm and extracellular polymeric substances (EPS) to biocides has emerged as a significant impediment to addressing these challenges. In this study, a promising strategy of calcium peroxide (CaO2) dosing assisted by free nitrous acid (FNA) pre-exposure overcame these limitations. Prior to a 6-hour exposure to 0.1 % (w/v) CaO2, a 2-hour pre-exposure to a low dose of 0.26 mg-N/L FNA demonstrated a significant enhancement in sulfide and methane control efficiency by 267.14 % and 390.47 %, respectively, compared to direct exposure to 0.2 % CaO2 for 12 h. Moreover, there was a notable increase of 40.05 % in soluble COD level in the effluent. FT-IR and XPS analyses discovered the disruption, migration, and dissolution of biofilm, accompanied by a substantial increase in membrane permeability (up to 2.89 folds). Additional analysis revealed that the synergistic effects of various reactive nitrogen/oxygen species destabilized the structure of EPS, e.g., declining total EPS yield, disintegrating humic acid-like and tryptophan- and protein-like substances, reducing hydrogen bond in β-sheet of proteins. Further down-regulation of node genes associated with sulfidogenesis and methanogenesis verified the toxic mechanism at the genetic level. Microbial community analysis revealed a significant reduction in the abundance of sulfate-reducing bacteria and methanogenic archaea, leading to an extended recovery period for sulfide and methane production in sewer biofilm. This study provides an effective strategy and in-depth mechanisms for biofilm control, applicable beyond sewer biofilm.

Effect of acidic environment exposure on mechanical properties of TRM composites

With the increasing application of textile-reinforced mortars (TRMs) for the strengthening of existing masonry structures, knowing the long-term behavior of these composites is increasingly of great importance. In recent years, there has been a progressive research effort on the durability of TRM composites following different aging protocols, yet the durability of TRMs still necessitates comprehensive experimental studies for a better understanding of their behavior. On the other hand, there is also a lack of established aging methods, including acidic attack.The present study aims to leverage knowledge of the durability of TRMs when exposed to acidic attack. For this purpose, two different commercial fabrics made of glass and basalt fibers and a lime-based mortar have been used. In parallel, two aging conditions were also investigated considering 1000, 3000, and 5000 hours of exposure. Overall, a total number of 462 specimens were tested, including tests for the matrix, fabric, and composite. Compressive, flexural, and elastic modulus tests studied the variation in the mechanical properties of mortar, tensile tests focused on the textiles, and pull-out and single-lap shear tests were used for TRM composite’s behavior. To investigate possible changes in material behavior due to aging, mineralogical and chemical analysis including Optical Microscopy, SEM, XRD, and TGA were carried out.

Characterising plasmacytoid and myeloid AXL+ SIGLEC-6+ dendritic cell functions and their interactions with HIV.

AXL+ Siglec-6+ dendritic cells (ASDC) are novel myeloid DCs which can be subdivided into CD11c+ and CD123+ expressing subsets. We showed for the first time that these two ASDC subsets are present in inflamed human anogenital tissues where HIV transmission occurs. Their presence in inflamed tissues was supported by single cell RNA analysis of public databases of such tissues including psoriasis diseased skin and colorectal cancer. Almost all previous studies have examined ASDCs as a combined population. Our data revealed that the two ASDC subsets differ markedly in their functions when compared with each other and to pDCs. Relative to their cell functions, both subsets of blood ASDCs but not pDCs expressed co-stimulatory and maturation markers which were more prevalent on CD11c+ ASDCs, thus inducing more T cell proliferation and activation than their CD123+ counterparts. There was also a significant polarisation of naïve T cells by both ASDC subsets toward Th2, Th9, Th22, Th17 and Treg but less toward a Th1 phenotype. Furthermore, we investigated the expression of chemokine receptors that facilitate ASDCs and pDCs migration from blood to inflamed tissues, their HIV binding receptors, and their interactions with HIV and CD4 T cells. For HIV infection, within 2 hours of HIV exposure, CD11c+ ASDCs showed a trend in more viral transfer to T cells than CD123+ ASDCs and pDCs for first phase transfer. However, for second phase transfer, CD123+ ASDCs showed a trend in transferring more HIV than CD11c+ ASDCs and there was no viral transfer from pDCs. As anogenital inflammation is a prerequisite for HIV transmission, strategies to inhibit ASDC recruitment into inflamed tissues and their ability to transmit HIV to CD4 T cells should be considered.

Female oviposition preferences and larval behavior of the Aedes aegypti mosquito (Linnaeus, 1762) exposed to predator cues (Odonata: Libellulidae)

The reproductive success of mosquitoes is heavily influenced by females' ability to select suitable oviposition sites for the proper development of their offspring. Many of these potential habitats may harbor predators, and the detection of these predators is crucial for assessing the risk of predation, which can, in turn, influence the behavior of the prey. However, there are often trade-offs to consider, which can impact the life history of these organisms. In our study, we investigated the oviposition preferences and larval behavioral responses of the Aedes aegypti mosquito when exposed to cues from predators and the actual presence of predation by Libellulidae (Odonata) larvae. We observed the mosquito's choices regarding oviposition with and without predation cues for a duration of ten weeks, following 48 hours of exposure. Additionally, we measured larval behavior across various treatments, including those with predation cues, predator cues, the presence of larvae, and controls with only water. Our findings revealed that the highest preference for oviposition occurred in containers with high organic matter content, regardless the presence of both predator cues and actual predators. Furthermore, we noted significant changes in larval behavior in response to predation cues, including evasive behaviors. When facing the risk of predation, larvae spent more time near the container's edges and exhibited discrete feeding behaviors or avoidance of the risk of predation. Conversely, in the absence of predation risk, larvae explored the entire container, swimming vigorously. These results highlight the significance of anti-predatory behaviors triggered by the recognition of predation cues in the context of Ae. aegypti's reproductive success.

Status of occupational exposure limits of air toxic substances in the GESTIS Substances Database

Objective: In order to understand the current situation of air toxic substances without occupational exposure limits (OELs) in the workplace in the Germany GESTIS Substance Database, and to provide an effective reference for formulating OELs of corresponding toxic substances and improving health standards. Methods: From March 2022 to May 2023, based on the standard of GBZ 2.1-2019 Occupational Exposure Limits for Hazardous Agents in the Workplace-Part 1: Chemical Hazardous Agents, air toxic substances without OELs in the standard of GBZ/T 300.1-2017 Determination of Toxic Substances in Workplace Air-Part 1: General Principles were screened out, then corresponding OELs in other countrie/regions were queried through the Germany GESTIS Substance Database. Results: Among the 333 kinds (classes) of air toxic substances in 160 parts of GBZ/T 300.1-2017 standard, 48 kinds (classes) of air toxic substances were screened out and had not yet been formulated OELs in GBZ 2.1-2019 standard. By querying the Germany GESTIS Substance Database, it was found that among the 48 kinds (classes) of air toxic substances, 35 kinds (classes) of air toxic substances had both 8-hour occupational exposure limit and short-term occupational exposure limit, 4 kinds (classes) of air toxic substances had 8-hour occupational exposure limit but no short-term occupational exposure limit, 9 kinds (classes) of air toxic substances hadn't been retrieved any OELs. In addition, standard test methods of 7 kinds of air toxic substances hadn't been published in the present, including trimethylchlorosilane, trimethylbenzenes, cumene, chloroethane, chloropropane, dibromoethane and acetophenone. Conclusion: In the process of formulating or revising the standards of GBZ 2.1-2019 and GBZ/T 300, the latest published OELs in the Germany GESTIS Substance Database could be used as a reference basis.

Improved method of dilating pupils for ophthalmic exams under anesthesia (faster and easier)

ObjectiveThe pupils of children with retinoblastoma are routinely dilated pre-procedure with Tropicamide and Phenylephrine. Despite that, the pupil constricts once general anesthesia begins. The aim of this study is to see if adding Ketorolac to the regular dilating drops given pre-procedure shortens the length of anesthesia. MethodsRetrospective comparison of time under anesthesia for two groups of retinoblastoma children receiving anesthesia for examination under anesthesia: one group (January 1, 2019 to October 1, 2022) had been dilated with Tropicamide 1% and Phenylephrine 2.5% while the second group (October 2, 2022 to July 1, 2023) was dilated with a combination drop using those drugs with topical Ketorolac 0.5% and Proparacaine 0.5%. ResultsAverage anesthesia time for patients who received the older two-drug combination was 25 minutes vs. 16 minutes (36% reduction in exposure time) for those who received the newer four-drug combination (9 minutes less anesthesia) (P < 0.001). ConclusionsThe use of a combined dilating drop that incorporated Tropicamide 1%, Phenylephrine 2.5%, Proparacaine 0.5% and Ketorolac 0.5% significantly shortened the time for exams under anesthesia for children with retinoblastoma because the pupil remained dilated after anesthesia induction with Sevoflurane. Using this combined drop, children will receive 5–10 hours less anesthesia during their treatment for retinoblastoma and staff will have more than 150 hours of fewer exposure to anesthetic gasses. In addition, far fewer drops are necessary pre-anesthesia, minimizing trauma to the children and families.

Association Between Early Hyperoxemia Exposure and Intensive Care Unit Mortality in Intracerebral Hemorrhage: An Observational Cohort Analysis.

Supraphysiologic levels of oxygen could have potential adverse effects on the brain that may be dose and time dependent in patients with brain injury. We therefore aimed to assess whether exposure to excess supplemental oxygen, measured as time-weighted mean exposure to hyperoxemia, was associated with intensive care unit (ICU) mortality in patients with intracerebral hemorrhage (ICH). In this single-center retrospective cohort study, we included all patients admitted to our ICU with a diagnosis of primary spontaneous ICH. To provide a longitudinal measure of hyperoxemia exposure, we calculated the hyperoxemia dose, defined as the area under the partial pressure of oxygen in arterial blood (PaO2) time curve above the threshold PaO2 value of 100mm Hg (13.3kPa) divided by the number of hours of potential exposure. To provide consistent potential exposure windows and limit bias from informative censoring, nested subsets were created with progressively longer exposure periods (0-1day, 0-2days, 0-3days, 0-4days, 0-5days, 0-6days, 0-7days). We used multivariable Cox regression, with hyperoxemia dose as a time-dependent covariate, to model ICU mortality. Admission ICH and Acute Physiology and Chronic Health Evaluation II scores were included as predictor covariables. A step-function extended Cox model was also fitted. Between September 2019 and July 2022, 275 patients met the inclusion criteria, with 24,588 arterial blood gas results available for analysis. The mean age was 57.19years (± 13.99), 59.64% were male, 23.64% had an infratentorial origin of hemorrhage, and ICU mortality was 35.64%. Almost all patients (97.45%) were exposed to hyperoxemia during their ICU admission. Cox regression modeling showed an association between hyperoxemia dose and ICU mortality (hazard ratio 1.15, confidence interval 1.05-1.25, p = 0.003). This association was observed in the 0-1day subset in the step-function extended Cox model (hazard ratio 1.19, confidence interval 1.06-1.35, p = 0.005) but not in any of the subsequent exposure periods. In patients with ICH admitted to the ICU, we observed an association between hyperoxemia dose and ICU mortality. Further prospective study is required to inform guidance on early systemic oxygen targets in ICH.

DIPG-65. NOVEL PATIENT-BASED PHARMACOKINETIC DRUG SCREENING REVEALS GEMCITABINE POTENTIAL IN PEDIATRIC H3K27-ALTERED DIFFUSE MIDLINE GLIOMAS

Abstract BACKGROUND Pediatric H3K27-altered diffuse midline glioma (DMG) remains incurable, with median overall survival of less than one year. Ineffectiveness of chemotherapy is largely attributed to the blood–brain barrier, hindering drug exposure to the tumor. Current drug sensitivity testing use concentrations vastly different from those attainable in the human brain, with optimal combination, timing, and sequence of drugs remaining underexplored. This study aims to systematically select and validate EMA/FDA approved drugs for effective treatment of DMG, based on human pharmacokinetics. METHODS In silico anticancer drug pharmacokinetic (PK) properties were correlated with published DMG cell sensitivities and ranked based on therapeutic index potential. Predictions of brain extracellular fluid time-concentration profiles (AUChumanECF) using plasma PK values of drug candidates, corresponding to human values, were made via physiologically based pharmacokinetic (PBPK) modeling with LeiCNS-PK3.0. In vitro cellular treatment protocols were established that mimic clinically achievable AUChumanECF, to be validated in vivo. RESULTS This PBPK drug screening approach revealed gemcitabine as a highly potent drug for DMG therapy for most cell lines tested (AUCplasma/AUCin_vitro = 337.6±233.0). Replicating a phase I clinical study in pediatric leukemia patients (3 weekly courses of 3600 mg/m2), 3 weekly 6-hour exposures to 12.5 µM.h gemcitabine demonstrated up to 99% cell kill as compared to viability at start of treatment. Notably, the cytotoxic effects of gemcitabine became apparent 3-5 days following drug exposure for most cell lines, and would have been missed using conventional drug screening with direct readouts. CONCLUSIONS This human PBPK-based drug screening approach underscores the significance of precise timing and dosing in elucidating clinically relevant therapeutic effects, highlighting high-dose gemcitabine as a potential therapy for DMG. Cytotoxic effects of gemcitabine on DMG cell viability are cumulative, and undetected when using conventional drug screening. This underlines the importance of investigating real-life human exposure patterns in the context of DMG.

Can condensed tannins improve fermentation patterns and the nutritive value of sorghum silage?

Context For an ensiling to succeed, the knowledge about the factors that might influence the fermentation dynamics and nutrient loss is mandatory. One of the strategies is the use of additives such as tannins, as they can decrease proteolysis and increase the total organic acids. Aims The aim was to investigate the effects of tannins on fermentation patterns and nutritional value of sorghum silage. Methods Silages containing 0.0, 7.5, 15.0, 22.5, and 30.0 g/kg of tannin on fresh matter were studied. To produce the silage, the tannin was added to the forage and manually homogenised before ensiling. The study was conducted in three experiments. In the first experiment, five replications of each level of inclusion were produced and assigned in a completely randomised design. The chemical composition and fermentation patterns of all experimental units were evaluated. The second experiment consisted of analysing the aerobic deterioration by using a PET bottles system. This experiment was conducted in a completely randomised split plot, with five replications and five treatments with the inclusion of different levels of tannin (main plots) and the hours of exposure of silage to air (subplot). In the third experiment, five levels of tannin (main plots) and incubation times (subplots) were evaluated as for in situ digestibility (ruminal degradability) in a randomised blocks design with three replications (animals). Key results The inclusion of tannins in sorghum silage caused quadratic effects on pH, acetic acid, lactic acid, total organic acids, ammonia nitrogen, dry matter content, crude protein content and in situ digestibility, when the level varied from 10.5 to 22.7 g tannin/kg fresh matter. There was a decreasing linear effect for aerobic deterioration as increasing levels of tannin in sorghum silage. Conclusions The inclusion of tannin as an additive in sorghum silage is recommended for the production of good quality silage. The use of condensed tannins optimise fermentation patterns (especially increasing lactic acid and decreasing ammoniacal nitrogen), chemical composition, providing less aerobic deterioration and improve digestibility. Implications This study revealed that condensed tannins can improve fermentation patterns and the nutritive value of sorghum silage.

Effect of postprandial gastric conditions on in vitro drug release from modified release mesalamine formulations

The effect of gastric prandial conditions on in vitro drug release from oral, locally acting, colon-targeted, mesalamine formulations has not been previously evaluated. In vitro dissolution of four mesalamine formulations were investigated using a USP II paddle apparatus. Fed gastric conditions were simulated under three consecutive phases of milk/buffer at different ratios to simulate changes in physicochemical, gastric composition during food digestion. Drug release was not observed from enteric coated preparations in the fasted state. Under simulative postprandial gastric conditions, however, drug release from Apriso® extended release (ER) capsules was 19 ± 4.7 %. As for Lialda® delayed release (DR) tablets, following two hours of exposure to simulative ileo-colonic media comprising bicarbonate buffer, drug release in the fed and fasted states was 55.7 ± 22.4 % and 12.4 ± 6.4 %, respectively. Significant differences in in vitro dissolution profiles were not observed between fasted and fed conditions for Pentasa® ER capsules and Asacol® HD DR tablets. Published pharmacokinetic data for Apriso and Lialda show higher systemic absorption of mesalamine in fed compared to fasted individuals. Our in vitro data is consistent with these pharmacokinetic findings since fed conditions may give rise to a higher extent of proximal drug release and therefore greater systemic absorption. Furthermore, extent of systemic exposure to mesalamine from Pentasa and Asacol was found not to be affected by food intake. In vitro dissolution studies simulating the gastric prandial state can possibly predict the impact of food on drug release from delayed and sustained release, locally acting formulations.

In vitro Evaluation of the Cytotoxicity of Chairside CAD/CAM Block Materials for Fabricating Dental Restorations.

The increasing utilization of chairside computer-aided design/computer-aided manufacturing (CAD/CAM) block materials in dentistry necessitates a comprehensive evaluation of their cytotoxicity to ensure patient safety. This study aimed to assess the cytotoxic effects of commonly used chairside CAD/CAM block materials for fabricating dental restorations. Several chairside CAD/CAM block materials including zirconia, lithium disilicate, and resin-based composites were evaluated for cytotoxicity using an in vitro model. Human gingival fibroblasts were cultured and exposed to extracts from each material. Cytotoxicity was assessed using MTT assay after 24, 48, and 72 hours of exposure. Additionally, cell morphology and viability were examined using microscopy. The MTT assay revealed varying degrees of cytotoxicity among the tested materials. Zirconia demonstrated the least cytotoxicity with cell viability of 85% ± 5%, 82% ± 4%, and 79% ± 6% at 24, 48, and 72 hours, respectively. Lithium disilicate exhibited moderate cytotoxicity with cell viability of 70% ± 6%, 65% ± 7%, and 60% ± 5% at the corresponding time points. Resin-based composites displayed the highest cytotoxicity with cell viability of 55% ± 8%, 45% ± 6%, and 40% ± 4% at 24, 48, and 72 hours, respectively. Microscopic examination revealed altered cell morphology and reduced cell viability in the presence of resin-based composites. Chairside CAD/CAM block materials exhibit varying degrees of cytotoxicity, with zirconia demonstrating the least and resin-based composites showing the highest cytotoxic effects. These findings underscore the importance of considering cytotoxicity profiles when selecting CAD/CAM materials for dental restorations to ensure patient safety and biocompatibility.

Aged polyethylene microplastics and glyphosate-based herbicide co-exposure toxicity in Pacific white shrimp (Litopenaeus vannamei)

Microplastics and glyphosate-based herbicides (GBHs) unavoidably contaminate aquatic environments, yet their combined effect on aquatic organisms has been scarcely investigated. We present a short-term study on individual and combined effects of aged polyethylene (PE) microplastics and GBH exposures at environmentally relevant concentrations on oxidative damage, antioxidant responses, immune parameters, and hepatopancreas histology in shrimp (Litopenaeus vannamei). In addition, acetylcholinesterase (AChE) was evaluated as a biomarker of GBH exposure. After 96 hours of exposure, individual PE microplastic exposure slightly influenced oxidative status, immune parameters, and histology. Decreases in AChE concentration and alterations in oxidative status, immunity, and cell population in hepatopancreas were observed in single GBH-exposed shrimp. The combinations of aged PE microplastics and GBH induced some changes that differed from individual GBH exposures. For instance, some alterations implied that the presence of aged PE microplastics may alter GBH toxicity to L. vannamei (AChE concentration and some expressions of immune-related genes). In conclusion, our results suggest that single exposure of aged PE microplastics at environmental concentration may slightly affect the health of L. vannamei and that aged PE microplastics are likely to modify the toxicity of other co-exposed chemicals.

Effect of air exposure time on erodibility of intertidal mud flats

This study investigates the influence of air exposure time on the erodibility of intertidal mud flats, emphasizing the role of evaporation in altering sediment strength and cohesion. Through a comprehensive approach combining laboratory experiments, fieldwork, and numerical modelling, it explores the dynamic interactions between sediment properties and environmental conditions. The research reveals that drying significantly reduces sediment erodibility, with pronounced effects observed during the initial hours of air exposure. Laboratory tests demonstrate a direct correlation between drying time and increased yield stress for both artificial and field-derived mud samples. Field observations further support these results, showing spatial and temporal variations in water content and shear strength across various locations on a tidal flat. The study emphasizes the critical impact of mud content on water retention and the subsequent effect on sediment stability. The incorporation of drying time into erosion formulations within a numerical model highlights the importance of considering evaporation processes in predicting the morphological evolution of tidal flats. This research contributes to a better understanding of sediment transport dynamics in intertidal zones, offering insights into the mechanisms driving the growth and stability of mud flats. It underscores the necessity of integrating evaporation effects into cohesive sediment transport models to enhance the accuracy of predictions concerning the erosion and accretion of intertidal environments.

Novel technique for the ultra-sensitive detection of hazardous contaminants using an innovative sensor integrated with a bioreactor

This study introduces an evaluation methodology tailored for bioreactors, with the aim of assessing the stress experienced by algae due to harmful contaminants released from antifouling (AF) paints. We present an online monitoring system equipped with an ultra-sensitive sensor that conducts non-invasive measurements of algal culture's optical density and physiological stage through chlorophyll fluorescence signals. By coupling the ultra-sensitive sensor with flash-induced chlorophyll fluorescence, we examined the dynamic fluorescence changes in the green microalga Chlamydomonas reinhardtii when exposed to biocides. Over a 24-h observation period, increasing concentrations of biocides led to a decrease in photosynthetic activity. Notably, a substantial reduction in the maximum quantum yield of primary photochemistry (FV/FM) was observed within the first hour of exposure. Subsequently, we detected a partial recovery in FV/FM; however, this recovery remained 50% lower than that of the controls. Integrating the advanced submersible sensor with fluorescence decay kinetics offered a comprehensive perspective on the dynamic alterations in algal cells under the exposure to biocides released from antifouling coatings. The analysis of fluorescence relaxation kinetics revealed a significant shortening of the fast and middle phases, along with an increase in the duration of the slow phase, for the coating with the highest levels of biocides. Combining automated culturing and measuring methods, this approach has demonstrated its effectiveness as an ultrasensitive and non-invasive tool for monitoring the physiology of photosynthetic cultures. This is particularly valuable in the context of studying microalgae and their early responses to various environmental conditions, as well as the potential to develop an AF system with minimal harm to the environment.

Preliminary studies on the effect of excretory secretory (ES) Ascaris lumbricoides antigens on colorectal cell line viability.

Helminth parasites are a group of complex metazoans from various taxonomic families. Excretory secretory (ES) by-products, secreted by living parasites from the surface, appeared to modulate the host immunological response towards helminth infection. This study aims to investigate the effect of ES antigen from helminth parasite on colorectal cell viability. Worm were cultured in phosphate-buffered saline (PBS x1) at 37°C for 24 hours after being rinsed in sterile PBS. Using a mortar and pestle, the worm was crushed vigorously using PBS. The obtained excretory secretory (ES) antigens were extracted and filtered using a 0.22 µM filter and stored at -20°C for further assay. For LCMS, 100 µl of the extract was analysed using Agilent ZORBAX Eclipse Plus C18 Rapid Resolution HT. The extraction of ES antigen (10 µg/ml and 20 µg/ml) was used for cell viability studies using CRC cell line HCT 116. Cell viability and MTT assay were conducted as per the protocol mentioned in the MTT kit. The liquid chromatography and mass spectrometry (LCMS) data indicated that the ES antigen contained metabolic compounds, namely fatty acid, amino alcohol, indoles, sterols, glycosides, and sphingoids. For the Ascaris lumbricoides LCMS analyses, around 405 metabolic peaks were detected. Out of which, 58 were detected via the database were identified, while several compounds detected have anticancer properties. The MTT assay indicated that after 24 hours and 48 hours of exposure, all treated cells showed a decrease in cell viability compared to the control group. The preliminary studies demonstrated that the ES antigen from Ascaris lumbricoides has some ability to decrease the cell viability of the HCT116 CRC cell line. Further studies are needed to examine the cell cycle arrest and apoptosis effect of the ES antigen towards the CRC cell line.