Simulated Conditions Research Articles

Monophosphate Derivatives of Luteolin and Apigenin as Efficient Precursors with Improved Oral Bioavailability in Rats

Luteolin (Lut) and apigenin (Apn), flavones present in various edible plants, exhibit diverse antioxidant and pharmacological activities but have limited in vivo efficacy due to low water solubility and poor bioavailability. Here, we generated luteolin and apigenin monophosphate derivatives (LutPs and ApnPs) individually via microbial biotransformation. We then characterized their physicochemical properties and evaluated their in vitro and in vivo pharmacokinetics and bioavailability. Both LutPs and ApnPs showed enhanced solubility and dissolution and remained stable in simulated gastrointestinal conditions. Additionally, they efficiently reverted to parental forms via alkaline phosphatase in Caco-2 cells. Following oral administration in rats, LutPs and ApnPs exhibited higher plasma exposure to both aglycone and conjugated forms compared to Lut and Apn. Notably, the in vivo biotransformation of Apn to Lut was observed in all apigenin-related groups. Our study suggests that flavone monophosphates are effective alternatives with enhanced bioavailability, providing insights for the potential application of emerging bioactive nutraceuticals.

Tracking Unique Device Identifiers (UDIs) of Mini Fragment Implants with a Novel Optical Imaging System

Background Small and mini fragment implantable medical devices (0.5 – 4.4mm) such as plates and screws that are placed into surgical trays pose a challenge to unique device identification (UDI) and tracking because they are difficult to directly mark, and often separated from labeling prior to reaching the point of care. Our objective was to demonstrate a novel optical system’s ability to track the unique identities of these small implants. Methods We performed a series of simulated craniotomy surgeries involving implants as small as 1.5mm in size, representing 13 different products from two manufacturers, to test whether a commercially available optical system (QuanTEK, Covisus, Inc.) could accurately track all implants through these simulations. The system was used to capture the unique surface texture of 236 implants at a micrometer scale and convert this to a unique “fingerprint” (vTag) for each item. Implants were placed in surgical trays, and these trays were subjected to a series of 16 simulated surgeries. After each surgery, trays were scanned and identified to determine which had been used, moved, or added. Results Post-surgical scans accurately identified the location and unique identity of 100% of implants (953 out of 953 times; 853 screws, 62 plates, 38 burr hole covers scanned; 95% confidence interval = 99.6 to 100%). Conclusions Results demonstrate that under simulated conditions, the system was able to register and verify the unique identities of mini fragment implants through surgical procedures with 100% accuracy. This technology could therefore be used to finally fulfill the goal of providing hospitals and supply chain management a solution to tracking the full UDI of all implantable medical devices used in the operating room, including the very smallest devices.

Oral Delivery of miR146a Conjugated to Cerium Oxide Nanoparticles Improves an Established T Cell-Mediated Experimental Colitis in Mice

Background: Dysregulated inflammation and oxidative stress are strongly implicated in the pathogenesis of inflammatory bowel disease. We have developed a novel therapeutic that targets inflammation and oxidative stress. It is comprised of microRNA-146a (miR146a)-loaded cerium oxide nanoparticles (CNPs) (CNP-miR146a). We hypothesized that oral delivery of CNP-miR146a would reduce colonic inflammation in a mouse model of established, chronic, T cell-mediated colitis. Methods: The stability of CNP-miR146a and mucosal delivery was assessed in vitro with simulated gastrointestinal fluid and in vivo after oral gavage by quantitative real-time RT-PCR. The efficacy of orally administered CNP-miR146a was tested in mice with established colitis using the model of adoptive naïve T-cell transfer in recombinant activating gene 2 knockout (Rag2−/−) mice. Measured outcomes included histopathology; CD45+ immune cell infiltration; oxidative DNA damage (tissue 8-hydroxy-2′-deoxyguanosine; 8-OHdG); expression of IL-6 and TNF mRNA and protein, and flow cytometry analysis of lamina propria Th1 and Th17 cell populations. Results: miR146a expression remained stable in simulated gastric and intestinal conditions. miR146a expression increased in the intestines of mice six hours following oral gavage of CNP-miR146a. Oral delivery of CNP-miR146a in mice with colitis was associated with reduced inflammation and oxidative stress in the proximal and distal colons as evidenced by histopathology scoring, reduced immune cell infiltration, reduced IL-6 and TNF expression, and decreased populations of CD4+Tbet+IFNg+ Th1, CD4+RorgT+IL17+ Th17, as well as pathogenic double positive IFNg+IL17+ T cells. Conclusions: CNP-miR146a represents a novel orally available therapeutic with high potential to advance into clinical trials.

Digging deep

Beach volleyball (BVB) tournaments often require elite athletes to compete in multiple matches per day over several consecutive days with limited rest, potentially leading to neuromuscular fatigue (NMF) and reduced performance. This study aimed to evaluate such fatigue. Twelve adult national team BVB players (8 males, 4 females) completed countermovement jump (CMJ) and 8-meter sprint tests before and after two simulated BVB matches, separated by a 2-hour rest period. No statistically significant changes were observed in performance measures at any time point. However, individual variations in CMJ height, which either increased or decreased beyond the smallest worthwhile change and typical error, were noted. These findings suggest that CMJ height alone may not be a reliable indicator of NMF, or that significant NMF does not occur following two BVB matches. Additionally, the validity of using sprint performance on sand to assess post-exercise NMF remains unverified. Future research should aim to include larger samples of elite athletes, address the limitations of simulated match conditions, and utilize more sensitive tools to evaluate NMF.

Alkali and alkaline earth metals cation effects on the formation of akageneite in corrosion products of steel artifacts embedded in soil: a study under simulated laboratory conditions

Alkali and alkaline earth metals cation effects on the formation of akageneite in corrosion products of steel artifacts embedded in soil: a study under simulated laboratory conditions

Co-encapsulation of vitamin D3 and Cordia myxa fruit peel extract in nanoemulsions

PurposeThis study investigated the production of free and encapsulated nanoemulsions using Cordia myxa fruit peel (CMFP) extract and vitamin D3.Design/methodology/approachThe CMFP extract was obtained using an ultrasonic technique, and its characteristics such as total phenolic content (TPC), antioxidant activity, cytotoxicity and gas chromatography-mass spectrometry (GC/MS) analysis were assessed. CMFP was encapsulated in vitamin D3 oil droplets of nanoemulsion prepared by ultra-homogenization using calcium alginate polymer. The nanoemulsions were evaluated for 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity, antimicrobial activity, morphology, Fourier transform infrared (FTIR) analysis and release rate in a simulated gastrointestinal model.FindingsThe GC/MS results revealed that pyrocatechol, cholestanoids and propionaldehyde were the predominant compounds in the extract. The highest cytotoxicity effect of CMFP was observed at concentrations of 6.25 and 12.5 ppm of the extract. Encapsulated nanoemulsions exhibited the highest antimicrobial activity against Escherichia coli (ATCC 35218). The antioxidant activity of the free and encapsulated nanoemulsions ranged from 25.81 to 36.08 mg/100g and 49.25–55.7 mg/100g, respectively. Free nanoemulsions showed a higher release rate in the simulated gastric model compared to encapsulated ones. The FTIR spectrum allowed for the identification of functional groups responsible for antioxidant and antibacterial properties, indicating that these properties of the nanoemulsions were maintained.Originality/valueThis study demonstrates the successful co-encapsulation of CMFP extract and vitamin D3 in nanoemulsions, which significantly enhanced the stability, bioavailability and functional properties of both compounds. Encapsulated nanoemulsions exhibited higher antioxidant and antimicrobial activities compared to their free counterparts, with controlled release in simulated gastrointestinal conditions. These findings confirm that nanoemulsion-based encapsulation is an effective strategy to protect and enhance the bioactivity of plant extracts and vitamins, supporting their potential use in functional food products and therapeutic application.

The underestimation of speed perception while walking in virtual reality with bodyweight unloading

As space agencies prepare for long-duration missions, such as establishing a permanent moon base, maintaining astronauts’ physical and mental health becomes crucial. Exercise is known to counteract the adverse effects of space travel, and virtual reality (VR) has the potential to enhance the psychological well-being of crew members. This study aimed to investigate the impact of bodyweight unloading on speed perception during treadmill walking in a VR environment. Eighteen participants walked on an AlterG treadmill while wearing a VR headset that displayed a moving virtual outdoor environment. The treadmill simulated different bodyweight conditions (100%, 60%, and 20%) to represent Earth’s gravity, intermediate, and lunar gravity, respectively. A staircase method was used to determine participants’ estimated threshold speed for perceiving visual speed equivalence. The results revealed that in all conditions, participants consistently underestimated their walking speed compared to the visual scene speed. No significant differences were found in estimated threshold speeds between the unloading conditions. Individual responses varied, possibly due to biomechanical differences and personal preferences. Participants reported no motion sickness symptoms, likely attributed to the short duration of speed mismatches and the use of high-resolution and high-refresh-rate VR equipment. This study provides insights into the combination of VR and treadmill walking, suggesting the importance of individual customization to enhance user experience and prevent motion sickness.

Assessing the effectiveness of cross-laminated timber (CLT) roof assembly moisture control and mitigation strategies: A field laboratory

Exposure to moisture and wetting is a concern in mass timber construction and service. Understanding the moisture conditions and the drying response of mass timber during construction and service can impact durability of the building material and occupant health because of the potential for biological degradation and mould growth, respectively. Cross-laminated timber (CLT) used in roof assemblies is particularly susceptible to high moisture loading from exposure to driving rain and extended periods of ponding and water retention on roofs during construction. The field research conducted in this study utilises a purpose-built CLT test facility in Toronto, ON to test and assess the impact of three specific moisture control strategies towards both mitigating moisture and increasing the dry-out rate of CLT used in roof assemblies. The moisture control strategies tested were: (1) the integration of an air cavity directly above the CLT within the roof assembly, (2) the protection of CLT during exposure and moisture loading periods on site, and (3) the permeability of membranes installed in the roof assembly and during site exposure. The CLT roof panels underwent four months of exposure to exterior environmental conditions followed by two months of bulk water inundation at the CLT test facility site immediately prior to installation and enclosure. Moisture content was monitored at evenly distributed depths in the CLT panels throughout exposure and inundation periods and for one year of simulated service conditions, post-enclosure. Comparative analysis of the moisture control strategies tested during this field laboratory demonstrate that the presence of an air layer above the CLT in the roof assembly consistently doubled the dry-out rate compared to the assemblies without an air cavity. The results also found that unprotected CLT panels took approximately 2.5 times longer to dry-out to below 15 % MC than protected panels and finally, that in comparing the results of using impermeable vs. permeable air/vapour barrier membranes on the surface of exposed CLT, that the impermeable membrane slowed the dry-out rate of wetted CLT by approximately 20 %. The results of this research support the implementation of specific moisture mitigation and control strategies during design and construction towards promoting rapid dry-out of CLT in roof assemblies in service.

Efficient Phosphorus capture from treated sanitary wastewater using a waste-derived SiO2@FeOOH composite: Robustness, Ca2+ interactions, and recovery perspectives

Phosphorus uptake and recovery from sanitary wastewater have been considered a promising approach to producing more sustainable fertilizers, in addition to reducing environmental damage caused by the discharge of this nutrient into water streams. In this study, the Phosphorus adsorption/desorption dynamics exhibited by a tailored SiO2@FeOOH adsorbent, produced using quartz sand waste and Fe derived from the acid dissolution of scrap iron, were examined. The adsorbent’s behavior, robustness, and interaction with Ca2+ ions in simulated treated sanitary wastewater were systematically investigated. As a result, the behavior of the adsorbent under controlled conditions was successfully modeled, and relevant interactions between the material and Ca2+ ions were identified under simulated conditions. The performance of the adsorbent was not affected by the presence of nitrate, carbonate, sulfate, ammonium, fluoride, and humic substances in the simulated media. Additionally, the composite can adsorb humic substances and Phosphorus simultaneously, without interfering with its Phosphorus adsorption capacity. In simulated treated wastewater, the adsorption of the nutrient was enhanced in the presence of Ca2+; however, the formation of insoluble Ca/P deposits on the adsorbent surface significantly changed the adsorption dynamics and disturbed the recovery of Phosphorus using the usual alkaline desorption method. The adsorbent exhibited a robust Phosphorus adsorption capacity as high as 40 mg P/g in simulated treated wastewater, showing clear potential for Phosphorus uptake in Wastewater Treatment Plants. Based on the experimental evidence, future perspectives on the final disposal of the spent adsorbent were also discussed within a circular economy framework.

Biochemical Characterization of Mannanase from Newly Isolated Acinetobacter sp. KUB-ST1-1 and its Hydrolysate Containing Mannooligosaccharides: Potential as Applied Prebiotic for Pet Food

The β-mannanase enzyme derived from isolated Acinetobacter sp. KUB-ST1-1 was studied for its potential for mannooligosaccharide production. Extracellular mannanase from Acinetobacter sp. KUB-ST1-1, cultured in nutrient broth with 0.5% (w/v) locust bean gum, was purified using ultrafiltration, anion exchange chromatography, and cation exchange chromatography. The enzyme, with a molecular weight of 57 kDa, had high activity in a 50 mM phosphate buffer at pH 6.0 and was stable from pH 4.0 to 7.0. It had high-temperature stability at 40 °C and 50 °C for up to 18 h. This enzyme was highly active toward konjac and galactomannan, especially with locust bean gum and copra meal. The hydrolysis products consisted mainly of the 2 and 3 units of mannooligosaccharide. The mannooligosaccharide exhibited prebiotic properties by promoting increased growth of some beneficial lactic acid bacteria. Furthermore, the defatted copra meal hydrolysate had considerable resistance to pepsin, trypsin, and bile salts under simulated gastrointestinal conditions for dogs. These characteristics highlighted the enzyme's excellent properties and suggested its potential as a promising candidate for applications in the food and bio-industries, particularly in pet food production.

Influence of Household Roof Types on the Development of Plasmodium vivax in Anopheles stephensi Mosquitoes.

Urbanization and microclimate variation in cities can influence mosquito behavior and parasite development, thus affecting malaria transmission. This study investigates how the impact of microclimate variations due to household roof types can aid in the survival of Anopheles stephensi and the development of Plasmodium vivax in an urban slum setting. Understanding these vital environmental interactions is essential for devising effective control strategies to achieve malaria elimination. Anopheles stephensi (F1) mosquitoes were membrane-fed with blood collected from P. vivax-infected patients before (day 0) and during (day 1) antimalarial treatment. The parasite development and mosquito survival were monitored in simulated microclimatic conditions of a variety of household roof types (thatched, asbestos, tiled) against standard laboratory conditions. Mosquito dissections were undertaken to detect oocysts and sporozoites in An. stephensi mosquitoes (oocyst: day 3-5, sporozoites: day 7-11). The maximum number of oocysts were detected in infected mosquitoes in thatched-roof conditions, whereas the largest oocyst was in the asbestos roof type. Circumsporozoite-ELISA results indicated the presence of sporozoites in infected mosquitoes for up to 29 days under standard conditions, 18 days in thatched-roof and asbestos roof conditions, and 14 days in tiled conditions. The univariate binary logistic regression model indicated a significant influence of microclimatic conditions of thatched roofs on parasite development. The Kaplan-Meier survival analysis revealed that the median survival of P. vivax-infected An. stephensi in thatched-roof conditions was 14 days, followed by asbestos (11 days) and tiled (10 days) roof conditions. In conclusion, thatched-roof houses were favorable for the development and survival of P. vivax-infected An. stephensi.

Generating synthetic turbulence with vector autoregression of proper orthogonal decomposition time coefficients

This study introduces vector autoregression (VAR) as a linear procedure that can be used for synthesizing turbulence time series over an entire plane, allowing them to be imposed as an efficient turbulent inflow condition in simulations requiring stationary and cross-correlated turbulence time series. VAR is a statistical tool for modelling and prediction of multivariate time series through capturing linear correlations between multiple time series. A Fourier-based proper orthogonal decomposition (POD) is performed on the two-dimensional (2-D) velocity slices from a precursor simulation of a turbulent boundary layer at a momentum thickness-based Reynolds number, $Re_{\theta }=790$ . A subset of the most energetic structures in space are then extracted, followed by applying a VAR model to their complex time coefficients. It is observed that VAR models constructed using time coefficients of 5 and 30 most energetic POD modes per wavenumber (corresponding to $66\,\%$ and $97\,\%$ of turbulent kinetic energy, respectively) are able to make accurate predictions of the evolution of the velocity field at $Re_{\theta }=790$ for infinite time. Moreover, the 2-D velocity fields from the POD–VAR when used as a turbulent inflow condition, gave a short development distance when compared with other common inflow methods. Since the VAR model can produce an infinite number of velocity planes in time, this enables reaching statistical stationarity without having to run an extremely long precursor simulation or applying ad hoc methods such as periodic time series.

Enhanced Thermoelectric Generator Power Output Based on Electrodeposited Bi2Te3 Nanocomposites with Pt NPs-CNTs Through Multiphysics Simulation

Thermoelectric generators (TEG) possess the potential to transform unused heat into electrical energy, making thermoelectricity a viable alternative for addressing the energy issue. This study provides insight into the enhanced power density of a TEG device when embedded with bismuth telluride (Bi2Te3) nanocomposite. The TEG power density has been analysed under the fluid flow simulation condition by utilizing several Bi2Te3 nanocomposite materials with Pt NPs-CNTs inclusion. The impact of static and steady air flow conditions has been studied using a detailed computational fluid dynamics (CFD) parameter, with flow velocities of 0.01 m/s and 1 m/s. As a main part of the work, the power density of nanocomposites embedded as N-type legs was compared to that of pure material. The Bi2Te3 with hybrid nanocomposite produces the highest power density, precisely combining Bi2Te3 with platinum nanoparticles (Pt Nps) and single-wall carbon nanotube (SWCNT) materials (Bi2Te3/Pt-SWCNTs). At velocity of 1 m/s, the power density was calculated to be 156.85μW/cm2, which increased to 158.86 μW/cm2 at a fluid velocity of 1 m/s, marking an 88% increment compared to the TEG model using pristine Bi2Te3 and higher than that of the previous work about 4 times of increment.

Modeling the behavior of probiotic strains in foods under simulated gastrointestinal tract conditions

This study aimed to estimate the survival of two Weizmannia coagulans and a Lacticaseibacillus paracasei probiotic strain under simulated gastrointestinal conditions using different food matrices (a Brazilian processed cheese – “requeijão cremoso," orange juice, and homemade bread). The probiotic Weizmannia strains remained stable throughout digestion, showing good resistance to solutions of the gastrointestinal tract. Lacticaseibacillus paracasei PXN 37 showed inactivation kinetics with a good model fit (R2>0.90) at pH 1 in orange juice, cream cheese and when inoculated purely directly in the gastric solution, when the counts of this strain were < 6 log CFU/g in both foods studied. In the other pH conditions evaluated (pH 2-4), the reductions in the populations of the probiotic strains did not impair their viability at the end of gastric digestion, as counts were always >6 log CFU/g or mL. Orange juice and processed cheese could be considered as viable food matrices for the application of probiotics. The modeling approach employed herein highlights the potential of this approach to screen suitable strains for the best dose adjustment, to use different probiotic strains in food formulations, to identify the conditions that inhibit/delay their growth, and to ascertain the limiting factors for the shelf life of the probiotic products.

Starch-based encapsulation to enhance probiotic viability in simulated digestion conditions

This research aims to meet the demand for efficient delivery systems in the food, nutraceutical, and pharmaceutical industries. The study involved the synthesis of starch-based nanoparticles for potential application in the encapsulation of Lactobacillus rhamnosus. Various techniques such as zeta sizer, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) were used to characterize the encapsulated probiotics in microbeads. The results showed 85.00 % encapsulation efficiency of beads. Microscopic analysis revealed that the probiotics accumulated within the wall material and formed small, smooth polygonal granules on the capsule surface. XRD analysis confirmed the presence of amorphous humps and some crystallinity of nanoparticles in the capsules. Moreover, encapsulation significantly improved probiotic viability under simulated gastrointestinal conditions. This study highlights the potential of starch-based nanoparticles to enhance the stability and viability of probiotics, demonstrating their potential applications across various industrial sectors. Further research should focus on investigating the long-term stability and functional efficacy of encapsulated probiotics in microbeads for real-world applications.

Comparative performance of pharmacogenetics-based warfarin dosing algorithms in Chinese population: use of a pharmacokinetic/pharmacodynamic model to explore dosing regimen through clinical trial simulation.

Warfarin has a narrow therapeutic window and large variability in dosing that are affected by clinical and genetic factors. To help guide the dosing of warfarin, the Clinical Pharmacogenetics Implementation Consortium has recommended the use of pharmacogenetic algorithms, such as the ones developed by the International Warfarin Pharmacogenetics Consortium (IWPC) and by Gage et al. when genotype information is available. In this study, simulations were performed in Chinese cohorts to explore how dosing differences between Western (by IWPC and Gage et al.) and Chinese algorithms (by Miao et al.) would mean in terms of anticoagulation effect in clinical trials. We first tried to replicate a published clinical trial comparing genotype-guided dosing to routine clinical dosing in Chinese patients. We then made simulations where Chinese cohorts received daily doses recommended by Gage, IWPC, and Miao algorithms. We found that in simulation conditions where dosing specifications were strictly followed, genotype-guided dosing by IWPC and Lenzini formulae was more likely to overshoot the upper limit of the therapeutic window by day 15, and thus may have a lower % time in therapeutic range (%TTR) than that of clinical dosing group. Also, in comparing Gage, IWPC, and Miao algorithms, we found that the Miao dosing cohort has the highest %TTR and the lowest risk of over-anticoagulation by day 28. In summary, our results confirmed that algorithms developed based on data from local patients may be more suitable for achieving therapeutic international normalized ratio window in Chinese population.

Approximation of sea surface velocity field by fitting surrogate two-dimensional flow to scattered measurements

In this paper, a rapid approximation method is introduced to estimate the sea surface velocity field based on scattered measurements. The method uses a simplified two-dimensional flow model as a surrogate model, which mimics the real submesoscale flow. The proposed approach treats the interpolation of the flow velocities as an optimization problem, aiming to fit the flow model to the scattered measurements. To ensure consistency between the simulated velocity field and the measured values, the boundary conditions in the numerical simulations are adjusted during the optimization process. Additionally, the relevance of quantity and quality of the scattered measurements is assessed, emphasizing the importance of the measurement locations within the domain as well as explaining how these measurements contribute to the accuracy and reliability of the sea surface velocity field approximation. The proposed methodology has been successfully tested in both synthetic and real-world scenarios, leveraging measurements obtained from Global Positioning System (GPS) drifters and high-frequency (HF) radar systems. The adaptability of this approach for different domains, measurement types and conditions implies that it is suitable for real-world submesoscale scenarios where only an approximation of the sea surface velocity field is sufficient.

Estimating the possible QPOs of [formula omitted] from the parameters of a hairy Kerr black hole

In this paper, we study the dynamics of the shock cone formed around a hairy Kerr black hole due to Bondi-Hoyle-Lyttleton (BHL) accretion and investigate the quasi-periodic oscillations (QPO) behaviors resulting from the black hole-cone interaction, aiming to predict the QPO frequencies that may occur around the M87∗ black hole. To achieve this, we use the hairy Kerr black hole parameters consistent with the observed shadow parameters of M87∗ as initial conditions in numerical simulations, revealing the structure of the resulting shock cone and QPOs in a strong gravitational field. Numerical calculations show that the deviation of the hairy Kerr black hole from the Kerr metric and the hair parameters significantly influence the complex behavior of the resulting QPOs. It is found that the Lense-Thirring effect and the pressure modes trapped within the cone lead to the excitation of QPOs. The hair parameter has been observed to suppress the resulting QPO frequencies. The Lense-Thirring effect, in a strong gravitational field with a black hole spin parameter of a/M>0.7, also suppresses other modes and generates high-frequency QPOs. It is predicted that the QPO frequencies observed around the M87∗ black hole could span a wide range from nHz to mHz. Using both Kerr and hairy Kerr gravities, the QPO frequencies formed around the M87∗ black hole can be explained. Especially in cases where the black hole is spinning rapidly, power spectrum density (PSD) analyses have shown very distinct low-frequency QPOs and resonance conditions in both gravities. By comparing the results obtained from numerical calculations with observational and analytical results, we discuss the observability of the QPO frequencies that may occur around the M87∗ black hole.

Characterization of two potential probiotic strains of Levilactobacillus brevis isolated from carp (Cyprinus carpio L.) with strong immunostimulatory activity on pikeperch (Sander lucioperca L.) head kidney cells

Aquaculture is inextricably linked to fish health problems, and the use of probiotic lactic acid bacteria (LAB) makes it possible to reduce losses caused mainly by bacterial pathogens. The aim of the present study was to isolate, characterize and select potential probiotic strains of lactic acid bacteria from the gut of common carp. We focused on obtaining strains that grow well under aerobic conditions to facilitate their future application through feed. After excluding strains with unwanted characteristics in vitro, two isolates of Levilactobacillus brevis were selected for this study. Despite belonging to the same species, the strains were biochemically different. However, both isolates met the in vitro selection criteria for potential probiotics. The tested L. brevis strains showed antagonistic activity against pathogenic bacteria isolated from carp and rainbow trout (Aeromonas hydrophila, Aeromonas salmonicida, Pseudomonas fluorescens, and Acinetobacter junii) and demonstrated co-aggregation ability with pathogens. Both strains tolerated stress well under simulated gastrointestinal tract conditions (i.e., showed acid and bile tolerance) and exhibited auto-aggregation capacity. The tested isolates were nonhemolytic, gelatinase negative and susceptible to most of the antibiotics tested. The cell-free supernatants of both L. brevis isolates exhibited strong immunostimulatory effects on pikeperch head kidney immune cells and immunomodulatory effects on carp immune cells. The results of in vitro tests encourage further research into the probiotic potential of these strains under in vivo conditions.

4D printing of biodegradable intestinal drug delivery devices with shape-memory effect.

Expanding devices designed to physically facilitate the permeation of drugs across the gastrointestinal mucosa are gaining attention for the oral delivery of therapeutic macromolecules. The ideal system should be biodegradable with latex-like properties, allowing it to withstand gut movement without breaking prematurely and preventing intestinal obstruction or damage. A highly foldable and elastic device is desirable because it can fit into commercial capsules by being compressed into confined spaces. However, this compression has limits due to the device's tendency to spring back to its original shape driven by stored elastic energy after deformation. This challenge can be addressed by using shape-memory polymers. In this work, we report a photo-crosslinkable resin suitable for 3D printing by digital light processing that yields an elastomer with latex-like properties, shape-recovery at body temperature, and degradation within 6 h under simulated intestinal conditions. Thermal shape-memory was conferred by adding stearyl(acrylate) to poly(β-aminoester)-based inks, achieving high elasticity (>700 %) and strength (>7.5 MPa), along with strain-hardening properties.