Search Results (63)

In an aquaponic system, fish and plants are cultivated together in a symbiotic environment where they mutually benefit, using significantly less water than traditional farming methods. The main aim of this study was to investigate the occurrence of antimicrobial resistance in two aquaponic systems implemented in two Chilean high schools using rainbow trout and lettuce cultures. When water samples (fish tank, biofilter, and plant raft) were analyzed over a three-month period, no resistance to oxytetracycline was detected, whereas the occurrence of resistance to florfenicol was rather small, ranging from 0.01% to 3.1% of bacterial culturable counts. Eighteen isolates were recovered from various sources as representatives of the florfenicol-resistant population, and all of them belonged to the Pseudomonas genus, showing a multi-drug-resistance phenotype and exhibiting simultaneous resistance to 7–13 antimicrobials. All isolates exhibited resistance to amoxicillin, chloramphenicol, florfenicol, and furazolidone and susceptibility to meropenem, oxytetracycline, oxolinic acid, flumequine, ciprofloxacin, and enrofloxacin. Five and two isolates carried the amphenicol-resistance-encoding genes floR and cmlA, respectively, whereas no carriage of integrons or the fexA, fexB, pexA, optrA, and cfr genes encoding for florfenicol resistance was detected. Eleven isolates carried plasmids, but only two of them were able to transfer their plasmid content by conjugation. The knowledge of the microbiome associated with aquaponic systems is still scarce, and their role as potential reservoirs of antimicrobial-resistant bacteria and related genes of these systems must be elucidated. Full article

Trypanosoma brucei causes African trypanosomiasis in humans. Infection with T. brucei elicits a potent pro-inflammatory immune response within infected human hosts, and this response is thought to at least be partially due to Toll-like receptor (TLR) activation. In response to stimulation by lipopolysaccharide and other pathogen antigens, TLR4 translocates to lipid rafts, which induces the expression of pro-inflammatory genes. However, cholesterol efflux is acknowledged as anti-inflammatory due to promoting lipid raft disruption. In this study, we wanted to assess the impact of T. brucei “ghosts”, which are non-viable T. brucei essentially devoid of intracellular contents, in stimulating macrophage TLR4 translocation to lipid rafts, and whether promoting cholesterol efflux in macrophages incubated with T. brucei ghosts attenuates TLR4-target gene expression. When cultured macrophages were exposed to T. brucei ghosts, we observed an increase in lipid raft TLR4 protein content, which suggests certain surface molecules of T. brucei serve as ligands for TLR4. However, pretreating macrophages with cholesterol acceptors before T. brucei ghost exposure decreased lipid raft TLR4 protein content and the expression of pro-inflammatory TLR4-target genes. Taken together, these results imply that macrophage cholesterol efflux weakens pro-inflammatory responses which occur from T. brucei infection via increasing macrophage lipid raft disruption. Full article

Amidst rapid societal changes and increasing urbanization, human connectivity with nature has declined, exacerbating public health concerns. This study assesses the efficacy of Shinrin-yoku, or ‘forest bathing’, in Wuyishan National Park as a simple and effective method to counteract the adverse health effects of contemporary lifestyles. Employing repeated-measures analysis of variance, forty-one participants were observed over three days across eight distinct forest settings. Techniques included eye-tracking for visual attention and soundscape perception assessments via questionnaires. Physiological responses were gauged through heart rate variability and skin conductance, while psychological evaluations utilized the Profile of Mood States (POMS) and Positive and Negative Affect Schedule (PANAS). Findings revealed that (1) natural soundscapes—especially birdsong, flowing water, wind, and bamboo raft sounds—and visual elements, such as distant mountains, streams, trees, Danxia landforms, tea gardens, and bamboo views, play pivotal roles in regulating heart rate variability, reducing arousal, and enhancing stress adaptation. Additionally, cultural landscapes, such as classical music and ancient structures, bolster parasympathetic activity. (2) Natural and cultural auditory stimuli, including flowing water and classical music, coupled with visual features, such as Danxia landforms, streams, distant mountains, lawns, and guide signs, effectively induce positive mood states, regulate mood disturbances, and enhance psychological well-being across diverse forest settings. These findings underscore the significant health benefits of immersive natural experiences and advocate for integrating forest-based wellness programs into public health strategies, offering compelling evidence for enriching life quality through nature engagement. Full article

The thermo- and pain-sensitive Transient Receptor Potential Melastatin 3 and 8 (TRPM3 and TRPM8) ion channels are functionally associated in the lipid rafts of the plasma membrane. We have already described that cholesterol and sphingomyelin depletion, or inhibition of sphingolipid biosynthesis decreased the TRPM8 but not the TRPM3 channel opening on cultured sensory neurons. We aimed to test the effects of lipid raft disruptors on channel activation on TRPM3- and TRPM8-expressing HEK293T cells in vitro, as well as their potential analgesic actions in TRPM3 and TRPM8 channel activation involving acute pain models in mice. CHO cell viability was examined after lipid raft disruptor treatments and their effects on channel activation on channel expressing HEK293T cells by measurement of cytoplasmic Ca²⁺ concentration were monitored. The effects of treatments were investigated in Pregnenolone-Sulphate-CIM-0216-evoked and icilin-induced acute nocifensive pain models in mice. Cholesterol depletion decreased CHO cell viability. Sphingomyelinase and methyl-beta-cyclodextrin reduced the duration of icilin-evoked nocifensive behavior, while lipid raft disruptors did not inhibit the activity of recombinant TRPM3 and TRPM8. We conclude that depletion of sphingomyelin or cholesterol from rafts can modulate the function of native TRPM8 receptors. Furthermore, sphingolipid cleavage provided superiority over cholesterol depletion, and this method can open novel possibilities in the management of different pain conditions. Full article

Thermoresponsive sol–gel transition polymers are of significant interest because of their fascinating biomedical applications, including as drug reservoirs for drug delivery systems and scaffolds for tissue engineering. Although extensive research has been conducted on lower critical solution temperature (LCST)-type sol–gel transition polymers, there have been few reports on upper critical solution temperature (UCST)-type sol–gel transition polymers. In this study, we designed an ABA-type triblock copolymer composed of a poly(ethylene glycol) (PEG) block and zwitterionic polymer blocks that exhibit UCST-type thermoresponsive phase transitions. A sulfobetaine (SB) monomer with both ammonium and sulfonate (–SO₃) groups in its side chain or a sulfabetaine (SaB) monomer with both ammonium and sulfate (–OSO₃) groups in its side chain was polymerized from both ends of the PEG block via reversible addition–fragmentation chain-transfer (RAFT) polymerization to obtain PSB-PEG-PSB and PSaB-PEG-PSaB triblock copolymers, respectively. Although an aqueous solution containing the PSB-PEG-PSB triblock copolymer showed an increase in viscosity upon cooling, it did not undergo a sol-to-gel transition. In contrast, a sol-to-gel transition was observed when a phosphate-buffered saline containing PSaB-PEG-PSaB was cooled from 80 °C to 25 °C. The PSaB blocks with –OSO₃ groups exhibited a stronger dipole–dipole interaction than conventional SB with –SO₃ groups, leading to intermolecular association and the formation of a gel network composed of PSaB assemblies bridged with PEG. The fascinating UCST-type thermoresponsive sol–gel transition properties of the PSaB-PEG-PSaB triblock copolymer suggest that it can provide a useful platform for designing smart biomaterials, such as drug delivery reservoirs and cell culture scaffolds. Full article

The entry of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) into human embryonic kidney (HEK293T) cells has been shown to be a cholesterol-rich, lipid raft-dependent process. In this study, we investigated if the presence of a cholesterol uptake receptor Niemann-pick type c1-like1 (NPC1L1) impacts SARS-CoV-2 cell entry. Initially, we utilized reporter-based pseudovirus cell entry assays and a spike (S) glycoprotein-mediated cell-to-cell fusion assay. Using Chinese hamster ovary (CHO-K1) cells, which lack endogenous receptors for SARS-CoV-2 entry, our data showed that the co-expression of NPC1L1 together with the ACE2 receptor synergistically increased SARS-CoV-2 pseudovirus entry even more than the cells expressing ACE-2 receptor alone. Similar results were also found with the HEK293T cells endogenously expressing the ACE2 receptor. Co-cultures of effector cells expressing S glycoprotein together with target cells co-expressing ACE-2 receptor with NPC1L1 significantly promoted quantitative cell-to-cell fusion, including syncytia formation. Finally, we substantiated that an elevated expression of NPC1L1 enhanced entry, whereas the depletion of NPC1L1 resulted in a diminished SARS-CoV-2 entry in HEK293T-ACE2 cells using authentic SARS-CoV-2 virus in contrast to their respective control cells. Collectively, these findings underscore the pivotal role of NPC1L1 in facilitating the cellular entry of SARS-CoV-2. Importance: Niemann-Pick type C1-like1 (NPC1L1) is an endosomal membrane protein that regulates intracellular cholesterol trafficking. This protein has been demonstrated to play a crucial role in the life cycle of several clinically important viruses. Although SARS-CoV-2 exploits cholesterol-rich lipid rafts as part of its viral entry process, the role of NPC1L1 in SARS-CoV-2 entry remains unclear. Our research represents the first-ever demonstration of NPC1L1’s involvement in facilitating SARS-CoV-2 entry. The observed role of NPC1L1 in human kidney cells is not only highly intriguing but also quite relevant. This relevance stems from the fact that NPC1L1 exhibits high expression levels in several organs, including the kidneys, and the fact that kidney damages are reported during severe cases of SARS-CoV-2. These findings may help us understand the new functions and mechanisms of NPC1L1 and could contribute to the identification of new antiviral targets. Full article

The presence of yessotoxins (YTXs) was analyzed in 10,757 samples of Galician bivalves from 2014 to 2022. Only YTX and 45-OH YTX were found. YTX was detected in 31% of the samples, while 45-OH YTX was found in 11.6% of them. Among the samples containing YTX, 45-OH YTX was detected in 37.3% of cases. The maximum recorded levels were 1.4 and 0.16 mg of YTX-equivalentsg⁻¹, for YTX and 45-OH YTX, respectively, which are well below the regulatory limit of the European Union. The YTX and 45-OH YTX toxicities in the raw extracts and extracts subjected to alkaline hydrolysis were strongly and linearly related. Due to the lack of homo-YTX in Galician samples, the effect of alkaline hydrolysis on homo-YTX and 45OH-Homo-YTX was only checked in 23 additional samples, observing no negative effect but a high correlation between raw and hydrolyzed extracts. Hydrolyzed samples can be used instead of raw ones to carry out YTXs determinations in monitoring systems, which may increase the efficiency of those systems where okadaic acid episodes are very frequent and therefore a higher number of hydrolyzed samples are routinely analyzed. The presence of YTX in the studied bivalves varied with the species, with mussels and cockles having the highest percentages of YTX-detected samples. The presence of 45-OH YTX was clearly related to YTX and was detected only in mussels and cockles. Wild populations of mussels contained proportionally more 45-OH YTX than those that were raft-cultured. Spatially, toxin toxicities varied across the sampling area, with higher levels in raft-cultured mussels except those of Ría de Arousa. Ría de Ares (ARE) was the most affected geographical area, although in other northern locations, lower toxin levels were detected. Seasonally, YTX and 45-OH YTX toxicities showed similar patterns, with higher levels in late summer and autumn but lower toxicities of the 45-OH toxin in August. The relationship between the two toxins also varied seasonally, in general with a minimum proportion of 45-OH YTX in July–August but with different maximum levels for raft-cultured and wild mussel populations. Interannually, the average toxicities of YTX decreased from 2014 to 2017 and newly increased from 2018 to 2021, but decreased slightly in 2022. The relationship between 45-OH YTX and YTX also varied over the years, but neither a clear trend nor a similar trend for wild and raft mussels was observed. Full article

Human capital is among the most important factors for sustainable economic growth. However, there remains some debate on the factors promoting or inhibiting its development. This research attempts to put socio-cultural factors at the front of this debate. Using econometric models, we exploratively test the influence of a raft of social and cultural variables on human capital development in multi-ethnic regions of Russia. We found that factors such as marriage, divorce, life expectancy, accessibility to education and healthcare, and attitude towards tourism all influence human capital to varying degrees. Domestic tourism, including museum and theatre visits were particularly impactful. We argue that cultural knowledge and exchange can promote socio-cultural harmony in multi-ethnic regions which can contribute to the region’s human capital development. By exploring the impact of socio-cultural factors, we hope to lead towards a holistic understanding of sustainable human capital development. Full article

The widespread applications of ZnO NPs in the different areas of science, technology, medicine, agriculture, and commercial products have led to increased chances of their release into the environment. This created a growing public concern about the toxicological and environmental effects of the nanoparticles. The impact of these NPs on the genetic materials of living organisms is documented in some cultured cells and plants, but there are only a few studies regarding this aspect in animals. In view of this, the present work regarding the assessment of the genotoxicity of zinc oxide nanoparticles using the mosquito Culex quinquefaciatus has been taken up. Statistically significant chromosomal aberrations over the control are recorded after the exposure of the fourth instar larvae to a dose of less than LD₂₀ for 24 h. In order to select this dose, LD₂₀ of ZnO NPs for the mosquito is determined by Probit analysis. Lacto-aceto-orcein stained chromosomal preparations are made from gonads of adult treated and control mosquitoes. Both structural aberrations, such as chromosomal breaks, fragments, translocations, and terminal fusions, resulting in the formation of rings and clumped chromosomes, and numerical ones, including hypo- and hyper-aneuploidy at metaphases, bridges, and laggards at the anaphase stage are observed. The percentage frequency of abnormalities in the shape of sperm heads is also found to be statistically significant over the controls. Besides this, zinc oxide nanoparticles are also found to affect the reproductive potential and embryo development as egg rafts obtained from the genetic crosses of ZnO nanoparticle-treated virgin females and normal males are small in size with a far smaller number of eggs per raft. The percentage frequencies of dominant lethal mutations indicated by the frequency of unhatched eggs are also statistically significant (p < 0.05) over the control. The induction of abnormalities in all of the three short-term assays studied during the present piece of work indicates the genotoxic potential of ZnO NPs, which cannot be labeled absolutely safe, and this study pinpoints the need to develop strategies for the protection of the environment and living organisms thriving in it. Full article

In recent years, the frequent outbreaks of Ulva prolifera in the South Yellow Sea have become the largest-scale green tide disasters in the world. The causes of its outbreaks have garnered widespread attention, particularly the coupled effects of multiple factors. Leveraging the Google Earth Engine (GEE) platform, this study conducted a long-term investigation of the Yellow Sea green tide disaster and the factors using multi-source satellite imagery. Finally, the combined effects of natural environmental changes and human activities on Ulva prolifera were analyzed by redundancy analysis (RDA) and variation partitioning analysis (VPA). The results indicate: (1) Since 2018, the scale of Ulva prolifera in the South Yellow Sea has shown a distinct “biennial” trend. (2) Regarding environmental factors, SST, PAR, precipitation, and windspeed have certain effects on the growth of Ulva prolifera. However, they cannot be considered as determining factors for the outbreak of Ulva prolifera (0.002 < R² < 0.14). Regarding anthropogenic factors, the recycle time of Pyropia yezoensis culture rafts has a relatively minor influence on the extent of Ulva prolifera. There exists a certain positive correlation (R² = 0.45) between the human footprint index (HFI) of Jiangsu Province and the annual variation in Ulva prolifera area in the South Yellow Sea. (3) The combined effects of multiple factors influence green tide outbreaks. The Ulvatotal explanatory power of SST, PAR, precipitation, windspeed, HFI, and the recycle time of Pyropia yezoensis culture rafts for the annual variation in the Ulva prolifera area is 31.8%, with these factors interweaving and mutually influencing each other. This study offers important insights into quantifying the driving forces behind Ulva prolifera in the South Yellow Sea, providing valuable information for a deeper comprehension of the complexity of marine ecosystems and sustainable management. Full article

Na/K-ATPase maintains transmembrane ionic gradients and acts as a signal transducer when bound to endogenous cardiotonic steroids. At subnanomolar concentrations, ouabain induces neuroprotection against calcium overload and apoptosis of neurons during excitotoxic stress. Here, the role of lipid rafts in interactions between Na/K-ATPase, sodium–calcium exchanger (NCX), and N-methy-D-aspartate receptors (NMDARs) was investigated. We analyzed 0.5–1-nanometer ouabain’s effects on calcium responses and miniature post-synaptic current (mEPSCs) frequencies of cortical neurons during the action of NMDA in rat primary culture and brain slices. In both objects, ouabain attenuated NMDA-evoked calcium responses and prevented an increase in mEPSC frequency, while the cholesterol extraction by methyl-β-cyclodextrin prevented the effects. The data support the conclusions that (i) ouabain-induced inhibition of NMDA-elicited calcium response involves both pre- and post-synapse, (ii) the presence of astrocytes in the tripartite synapse is not critical for the ouabain effects, which are found to be similar in cell cultures and brain slices, and (iii) ouabain action requires the integrity of cholesterol-rich membrane microdomains in which the colocalization and functional interaction of NMDAR-transferred calcium influx, calcium extrusion by NCX, and Na/K-ATPase modulation of the exchanger occur. This regulation of the molecules by cardiotonic steroids may influence synaptic transmission, prevent excitotoxic neuronal death, and interfere with the pharmacological actions of neurological medicines. Full article

Cholesterol-rich membrane domains, also called lipid rafts (LRs), are specialized membrane domains that provide a platform for intracellular signal transduction. Membrane proteins often cluster in LRs that further aggregate into larger platform-like structures that are enriched in ceramides and are called ceramide-rich platforms (CRPs). The role of CRPs in the regulation of intestinal epithelial functions remains unknown. Down-regulated in adenoma (DRA) is an intestinal Cl⁻/HCO₃⁻ antiporter that is enriched in LRs. However, little is known regarding the mechanisms involved in the regulation of DRA activity. The air–liquid interface (ALI) was created by removing apical media for a specified number of days; from 12–14 days post-confluency, Caco-2/BBe cells or a colonoid monolayer were grown as submerged cultures. Confocal imaging was used to examine the dimensions of membrane microdomains that contained DRA. DRA expression and activity were enhanced in Caco-2/BBe cells and human colonoids using an ALI culture method. ALI causes an increase in acid sphingomyelinase (ASMase) activity, an enzyme responsible for enhancing ceramide content in the plasma membrane. ALI cultures expressed a larger number of DRA-containing platforms with dimensions >2 µm compared to cells grown as submerged cultures. ASMase inhibitor, desipramine, disrupted CRPs and reduced the ALI-induced increase in DRA expression in the apical membrane. Exposing normal human colonoid monolayers to ALI increased the ASMase activity and enhanced the differentiation of colonoids along with basal and forskolin-stimulated DRA activities. ALI increases DRA activity and expression by increasing ASMase activity and platform formation in Caco-2/BBe cells and by enhancing the differentiation of colonoids. Full article

Chitosan is a polysaccharide extracted from animal sources such as crab and shrimp shells. In this work, chitosan films were modified by grafting them with a thermoresponsive polymer, poly(di(ethylene glycol) methyl ether methacrylate) (PMEO₂MA). The films were modified to introduce functional groups useful as reversible addition–fragmentation chain transfer (RAFT) agents. PMEO₂MA chains were then grown from the films via RAFT polymerization, making the chitosan films thermoresponsive. The degree of substitution of the chitosan-based RAFT agent and the amount of monomer added in the grafting reaction were varied to control the length of the grafted PMEO₂MA chain segments. The chains were cleaved from the film substrates for characterization using ¹H NMR and a gel permeation chromatography analysis. Temperature-dependent contact angle measurements were used to demonstrate that the hydrophilic–hydrophobic nature of the film surface varied with temperature. Due to the enhanced hydrophobic character of PMEO₂MA above its lower critical solution temperature (LCST), the ability of PMEO₂MA-grafted chitosan films to serve as a substrate for cell growth at 37 °C (incubation temperature) was tested. Interactions with cells (fibroblasts, macrophages, and corneal epithelial cells) were assessed. The modified chitosan films supported cell viability and proliferation. As the temperature is lowered to 4 °C (refrigeration temperature, below the LCST), the grafted chitosan films become less hydrophobic, and cell adhesion should decrease, facilitating their removal from the surface. Our results indicated that the cells were detached from the films following a short incubation period at 4 °C, were viable, and retained their ability to proliferate. Full article

Aquaculture has important economic and environmental benefits. With the development of remote sensing and deep learning technology, coastline aquaculture extraction has achieved rapid, automated, and high-precision production. However, some problems still exist in extracting large-scale aquaculture based on high-resolution remote sensing images: (1) the generalization of large-scale models caused by the diversity of remote sensing in breeding areas; (2) the confusion of breeding target identification caused by the complex background interference of land and sea; (3) the boundary of the breeding area is difficult to extract accurately. In this paper, we built a comprehensive sample database based on the spatial distribution of aquaculture, and expanded the sample database by using confusing land objects as negative samples. A multi-scale-fusion superpixel segmentation optimization module is designed to solve the problem of inaccurate boundaries, and a coastal aquaculture network is proposed. Based on the coastline aquaculture dataset that we labelled and produced ourselves, we extracted cage culture areas and raft culture areas near the coastline of mainland China based on high-resolution remote sensing images. The overall accuracy reached 94.64% and achieved a state-of-the-art performance. Full article

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus is the causative agent of the COVID-19 disease. COVID-19 viral infection can affect many cell types, including epithelial cells of the lungs and airways. Extracellular vesicles (EVs) are released by virtually all cell types, and their packaged cargo allows for intercellular communication, cell differentiation, and signal transduction. Cargo from virus-infected cells may include virally derived metabolites, miRNAs, nucleic acids, and proteins. We hypothesized that COVID-19 plasma EVs can induce the formation of signaling platforms known as lipid rafts after uptake by normal human small airway epithelial cells (SAECs). Circulating EVs from patients with or without COVID-19 were characterized by nanoparticle tracking analysis, Western blotting using specific antibodies, and transmission electron microscopy. Primary cultures of normal human small airway epithelial cells were challenged with EVs from the two patient groups, and lipid raft formation was measured by fluorescence microscopy and assessed by sucrose density gradient analysis. Collectively, our data suggest that circulating EVs from COVID-19-infected patients can induce the formation of lipid rafts in normal human small airway epithelial cells. These results suggest the need for future studies aimed at investigating whether the increased density of lipid rafts in these cells promotes viral entry and alteration of specific signaling pathways in the recipient cells. Full article