Min Of Exposure Research Articles

Innovative application of plasma-activated water in the inactivation of Escherichia coli: Temperature-dependent chemical processes leading to the synergistic microbicidal effect

Plasma-based technologies, including plasma-activated water (PAW), offer the capability to deactivate microorganisms on fruits and vegetables, preserving their sensory and nutritional quality. Although many studies have reported a synergistic microbicidal effect between PAW and mild heating, the underlying chemical processes driving these effects remain unexplored. Our study aims to evaluate the microbicidal capacity of two PAW types, one containing NO2− (PAW-N) and the other H2O2 (PAW-H), as well as their mixture (PAW-M), at different temperatures, and to elucidate the underlying temperature-dependent chemical processes. Using E. coli DH5α as the target microorganism, we measured colony-forming units under varying exposure times for each PAW type and their mixture at 8 and 28 °C. Additionally, we determined the time-dependent concentrations of NO2−, H2O2, and NO3− in the mixture, and calculated the reaction rate constant for peroxynitrous acid generation. The kinetic study revealed a fivefold increase in the reaction constant between H2O2 and NO2− in PAW-M at 28 °C compared to 8 °C, leading to a significant rise in hydroxyl radical production. The microbicidal efficacy of PAW-M exceeded that of individual PAWs or temperatures. Moreover, this effect was significantly enhanced by mild heating, resulting in log reductions of 0.24, 0.34, 2.3 (at 8 °C) and 0.74, 2.3, 3.6 (at 28 °C) for PAW-H, PAW-N, and PAW-M, respectively, after a 10-min exposure. In conclusion, the synergistic effect between PAW and mild heating may be attributed to the accelerated reaction rate of peroxynitrous acid formation in an acidic medium, leading to heightened hydroxyl radical generation.

Influence of thermal heat load accumulation on daily rumination time of lactating Holstein cows in a zone with temperate climate

In the future, conflicts between animal welfare and climate change will gradually intensify. In the present study, we investigated the daily rumination time (RT) of lactating Holstein-Friesian cows in a zone with temperate climate and the effects of heat load duration and heat load intensity. Responses of individual cows to heat load were assessed, adjusting for milk yield, lactation number, days in milk as well as reproductive status and season. A total of 27,149 data points from 183 cows in a naturally ventilated barn in Brandenburg, Germany, were collected from June 2015 to May 2017. Ambient temperature and relative humidity were recorded at eight positions inside the barn every 5 min, and the temperature-humidity index (THI) was calculated. Based on THI, the degree of heat load was determined, using critical thresholds of THI = 68, 72, and 80. Daily RT was measured with a microphone-based sensor system (collar) on the cow's neck. The analysis models included autocorrelations in time series as well as individual cow-related effects. With each 5 min exposure to contemporaneous heat load, a decrease of approximately 1.17 min d−1 in RT per cow from non-heat stress to heat stress conditions by exceeding THI ≥68 (p < 0.01). This effect was intensified by exceeding the critical THI thresholds of 68 and 72.As heat load duration and intensity increased, daily RT decreased in comparison to daily RT under non-stress conditions. High-yielding (>38.4 kg milk/day) cows were more influenced in rumination time than low-yielding (≤28.8 kg milk/day) cows. With moderate contemporaneous heat load, RT decreased by 0.14 min d−1 per 5 min in high-yielding cows compared to low-yielding cows under moderate heat load. A decrease of 0.1 min d−1 was found in daily RT of mid-yielding cows. However, the delayed effects of heat load (one to three days after the heat stress event) were associated with days in milk and reproduction status. When the heat load duration lasted for several days, the responses were less pronounced than the impacts of contemporaneous heat load (when the heat stress event lasted for one day). Delayed mild heat load resulted in an increase in RT by 0.13 min d−1 in lactating cows ≤60 DIM. This was also found with delayed moderate heat load. Lactating cows ≤60 DIM showed a rise of 0.09 min d−1 in RT. RT also showed interactions with reproduction status of cows under delayed moderate heat stress. Lactating cows with ≤180 days of pregnancy showed an increase of 0.61 min d−1 in RT. Similarly, cows with >180 days of pregnancy had 0.64 min d−1 more RT compared to non-pregnant cows. Further analysis with higher temporal resolution of RT than data accumulation in 24-h blocks as well as the assessment of the correlation between feed composition, intake and rumination will elucidate the influence of heat load on daily RT.

A systematic investigation of the transfer of polyphosphate/inorganic silicate flame retardants from epoxy resins to layered glass fiber‐reinforced composites and their post‐furnace flexural properties

AbstractThe systematic transfer of solvent‐free, additive flame retardant (FR) formulations from epoxy resins to glass fiber‐reinforced epoxy composites (GFRECs) through prepregs is difficult. Additionally, obtaining data on their post‐fire mechanics is often challenging. Utilizing melamine polyphosphate (MPP), ammonium polyphosphate (APP), and silane‐coated ammonium polyphosphate (SiAPP) FRs with low‐melting inorganic silicates (InSi) in an 8:2 proportion and 10% loading by weight in a diglycidyl ether of bisphenol A (DGEBA) resin, a systematic investigation of the processing properties, room‐temperature mechanics, and temperature‐based mechanics of the systems was performed. The resin was cured with a dicyandiamide hardener (DICY) and a urone accelerator. The results revealed no substantial impact of these FRs at the current loading on the resin's glass transition temperature or processability. However, the fire residues from cone calorimetry tests of the composites containing FRs were found to be only 15‐20% of the thickness of the resins, implying a suppression of intumescence upon transfer. At room temperature, the decrease in the flexural modulus for the composites containing FRs was negligible. Exposure of the composites in a furnace at 400°C as a preliminary study before ignition tests was shown to cause significant flexural moduli reductions after 2.5 min of exposure and complete delamination after 3 min making further testing unviable. This study emphasizes the need for future research on recovering modes of action upon transfer of FR formulations from resins to composites. Based on the challenges outlined in this investigation, sample adaptation methods for post‐fire analysis will be developed in a future study.Highlights Processibility of resins for prepreg production unaffected by polyphosphate/inorganic silicate flame retardants (FRs). FR formulations had a negligible effect on the mechanics of the composites. 15%–25% increase in the fracture toughness of the DGEBA‐based resin matrix with FRs. Suppression of intumescent behavior in the composites verified quantitatively. Significant reduction in flexural moduli of the composites post‐400°C exposure in a furnace.

Synthesis of Ag2CO3/TiO2/SiC with pH stability and chloride ion boosted for efficient photodegrading tetracycline under visible light

The increasing issue of antibiotic contamination in water has sparked significant interest in seeking effective solutions. In this research, a dual Z-scheme ternary photocatalyst Ag2CO3/TiO2/SiC (ATS) was synthesized by a mechanochemical-coprecipitation method. The experimental results demonstrated that the 15 %Ag2CO3/TiO2/SiC (ATS-15) reached a remarkable tetracycline (TC) degradation efficiency of 95.87 % (k = 0.1063 min−1) after a 30 min exposure to visible light, which was 46.22 and 13.63 times more effective than SiC (k = 0.0023 min−1) and TiO2/SiC (k = 0.0078 min−1), respectively. The synergistic effect of ATS ternary structure to promote Si electron transfer and SiC surface oxidation. The photocatalytic performance of ATS-15 was greatly enhanced due to the synergistic effect of Cl− and CO3•−, achieving 95 % of TC degradation within 5 min. In the ATS-15 system, Cl− converts a portion of Ag2CO3 into AgCl and establishes a quaternary electron transfer scheme with ATS-15, thereby enhancing the performance of the photocatalyst. ATS-15 photocatalyst can maintain TC degradation rate above 90 % among pH 3 to 9. The ATS-15 system also exhibits excellent adaptability to various water environment, achieving 94.01 % TC degradation rate in natural river water, with only a 1 % reduction. A novel treatment scheme for antibiotic pollution in a complex water environment was proposed by ATS-15 photocatalyst with high pH stability and water applicability.

Discussion Abounds on the Potential Carcinogenic Risks Associated With the Use of UV Curing Lamps for Permanent Nail Polish

BackgroundControversy has recently broken out over the potential carcinogenic risk associated with exposure to UV lamps for permanent nail polish. The new LED-based polymerization devices, and their potential biological effect has not been analyzed to this date. ObjectiveTo evaluate the emission power and its potential biological effects on the skin of 2 types of UV LED and fluorescent curing lamps under normal use conditions compared to doses of sunlight exposure. Material and methodsThe emission spectrum (290nm to 450nm) of curing lamps and the Sun at noon on an average summer day in mid-latitude Spain was analyzed. The effective biological irradiance potential for erythema, non-melanoma skin cancer, DNA damage, photoimmunosuppression and permanent pigmentation was also characterized. ResultsThe high-energy UVA-visible irradiance emitted by these devices was similar to the one coming from the Sun in that spectral range while the effective biological doses were lower or similar to those also coming from the Sun. The total UV and high-energy visible dose per manicure session corresponded to that obtained from 3.5min to 6min exposures to the Sun at noon in the summer days at our latitudes. ConclusionsThe exposure times and doses received with the common use of artificial lamp nail drying correspond to sunlight exposures of 3min to 5min in the central hours of the day. This represents a very low carcinogenic potential compared to sunlight exposure, although similar regarding immunosuppressive potential. Photoprotective measures would further minimize the risks.

Development of Intelligent Indicators Based on Cellulose and Prunus domestica Extracted Anthocyanins for Monitoring the Freshness of Packaged Chicken.

Meat is a widely consumed food globally; however, variations in storage conditions along its supply chain can pose a potential food safety risk for consumers. Addressing this concern, we have developed freshness indicators designed to monitor the condition of packaged chicken. In this study, anthocyanins were infused with cellulose paper measuring 2 × 2 cm, and subsequent analysis focused on examining color changes concerning deteriorating chicken stored at 30°C for 48 h, with varying sample sizes being considered. The rise in total volatile nitrogen (TVB-N) compounds from an initial value of 3.64 ± 0.39 mg/100 g to 28.17 ± 1.46 mg/100 g acted as the stimulus for the color change in the indicator, simultaneously influencing the pH from the initial 7.03 ± 0.16 to 8.12 ± 0.39. The microbial load (aerobic plate count) of the chicken samples was also significantly increased. This collective shift in various parameters strongly suggests the occurrence of spoilage in chicken meat. The pH indicators exhibited a dark pink to red color for fresh chicken. As the chicken meat turned towards spoilage, the indicators changed to a dark blue and then a pale green color. FTIR spectroscopy results confirmed the presence of cellulose and anthocyanins. The FTIR analysis also validated the immobilization of plum anthocyanins within the cellulose paper and assessed their stability after 8 months of storage. Notably, the indicators demonstrated rapid sensitivity, showing a 20.5% response within one minute of ammonia exposure, which further increased to 29.5% after 3 min of exposure. The total color difference (ΔE) steadily rose in all the examined samples and also under various storage conditions. Overall, the indicators developed in this study exhibited a highly pronounced color transition, capable of distinguishing between fresh and spoiled chicken samples depending on the extent of spoilage and the specific day of observation.

Short-term passive greenspace exposures have little effect on nasal microbiomes: A cross-over exposure study of a Māori cohort

Indigenous health interventions have emerged in New Zealand aimed at increasing people's interactions with and exposure to macro and microbial diversity. Urban greenspaces provide opportunities for people to gain such exposures. However, the dynamics and pathways of microbial transfer from natural environments onto a person remain poorly understood. Here, we analysed bacterial 16S rRNA amplicons in air samples (n = 7) and pre- and post-exposure nasal samples (n = 238) from 35 participants who had 30-min exposures in an outdoor park. The participants were organised into two groups: over eight days each group had two outdoor park exposures and two indoor office exposures, with a cross-over study design and washout days between exposure days. We investigated the effects of participant group, location (outdoor park vs. indoor office), and exposures (pre vs. post) on the nasal bacterial community composition and three key suspected health-associated bacterial indicators (alpha diversity, generic diversity of Gammaproteobacteria, and read abundances of butyrate-producing bacteria). The participants had distinct nasal bacterial communities, but these communities did not display notable shifts in composition following exposures. The community composition and key health bacterial indicators were stable throughout the trial period, with no clear or consistent effects of group, location, or exposure. We conclude that 30-min exposure periods to urban greenspaces are unlikely to create notable changes in the nasal microbiome of visitors, which contrasts with previous research. Our results suggest that longer exposures or activities that involves closer interaction with microbial rich ecological components (e.g., soil) are required for greenspace exposures to result in noteworthy changes in the nasal microbiome.

Synthesis of carboxylated cellulose nanocrystal/ZnO nanohybrids using Oxytenanthera abyssinica cellulose and zinc nitrate hexahydrate for radical scavenging, photocatalytic, and antibacterial activities

The extremely low antioxidant, photocatalytic, and antibacterial properties of cellulose limit its application in the biomedical and environmental sectors. To improve these properties, nanohybrides were prepared by mixing carboxylated cellulose nanocrystals (CCNCs) and zinc nitrate hexahydrate. Data from FTIR, XRD, DLS, and SEM spectra showed that, ZnO nanoparticles, with a size ranging from 94 to 351 nm and the smallest nanoparticle size of 164.18 nm, were loaded onto CCNCs. CCNCs/ZnO1 nanohybrids demonstrated superior antibacterial, photocatalytic, and antioxidant performance. More considerable antibacterial activity was shown with a zone of inhibition ranging from 26.00 ± 1.00 to 40.33 ± 2.08 mm and from 31.66 ± 3.51 to 41.33 ± 1.15 mm against Gram-positive and Gram-negative bacteria, respectively. Regarding photodegradation properties, the maximum value (∼91.52 %) of photocatalytic methylene blue degradation was observed after 75 min exposure to a UV lamp. At a concentration of 125.00 μm/ml of the CCNC/ZnO1 nanohybrids sample, 53.15 ± 1.03 % DPPH scavenging activity was obtained with an IC50 value of 117.66 μm/ml. A facile, cost-effective, one-step synthesis technique was applied to fabricate CCNCs/ZnO nanohybrids at mild temperature using Oxytenanthera abyssinica carboxylated cellulose nanocrystals as biotemplate. The result showed that CCNCs/ZnO nanohybrids possess potential applications in developing advanced functional materials for dye removal and antibacterial and antioxidant applications.

Estimating specific acute exposure guideline levels for emergency response at the scene of chemical accidents: A case study of acrylic acid

Acute Exposure Guideline Levels (AEGLs) proposed by the United States Environmental Protection Agency (USEPA) are reference values for disaster management during scenarios involving chemical accidents. We attempted to specify the present AEGLs of acrylic acid that are provided with only five intervals (10, 30 min, 1, 4, and 8 h) as a brief case study. The AEGL-1, 2, 3 values for acrylic acid were estimated at 96 intervals (5 min–8 h) in detail using the revised Haber's formula (k = Cn × t) and applying a regression model. The AEGL-1 value was constant for the entire exposure duration of 1.5 ppm since it caused only slight irritation without irreversible health effects. The AEGL-2 value was obtained with fixed values (n = 1.8, uncertainty factor of 3, and each 5 min interval), with that for the initial 5 min being derived as 183 ppm, which decreased to 43 ppm after 8 h of exposure. The AEGL-3 values fluctuated because of the risk to human health. The AEGL-3 for the initial 5 min exposure was derived as 696 ppm, which decreased to 58 ppm after 8 h exposure applied to the regression model. Specific AEGL values for acrylic acid were derived using toxicity data and the revised Haber's formula. By applying the methodology described in this study, the reference values for chemical substances that have no AEGL values can be calculated to potentially enhance emergency response in the event of chemical accidents.

Anesthetic effects of eugenol on adult ridgetail white prawn (Exopalaemon carinicauda) and its protective effects under simulated transportation

Anesthesia is a common practice used to improve animal welfare and reduce the negative impacts of stress factors in aquaculture settings. However, few studies have been conducted to investigate the application of anesthetics in ridgetail white prawn (Exopalaemon carinicauda). In the present study, the anesthetic efficacy and protective effects of eugenol in adults of this species were evaluated. When the prawns (n = 5) were immersed in different concentrations of eugenol in the range of 0–240 μL/L for 30 min, the results showed that 180 and 240 μL/L could lead to quick sedative and anesthesia effects with 100% mortality after 30 min exposure, while 30 μL/L failed to induce any sedative and anesthesia effects. Further tests showed that adult individuals were quickly anesthetized by eugenol at a concentration of 60–90 μL/L with a 30 min immersion, while half of the prawns were sedated in 30 μL/L eugenol after 4 h exposure, then recovered at 2 h without any mortality. Furthermore, we checked the water quality parameters after the adult prawns were immersed in four eugenol concentrations (0, 10, 20, 30 μL/L) for 8 h of simulated transportation followed by a 96 h recovery, we found that 30 μL/L eugenol treatment could significantly decrease the ammonia nitrogen concentration, and increased the survival rate at 96 h post recovery. The oxidative responses of the prawns during the 8 h transportation at 30 μL/L eugenol followed by 96 h recovery period were analyzed. The results showed that eugenol administration significantly decreased the malonaldehyde (MDA) concentration and the activities of most antioxidant-related enzymes immediately. The present data indicated that eugenol was an efficient anesthetic, which could be used for long-distance transportation of this species. It exhibited excellent protective effects to improve the animal's welfare by improving water quality and alleviating oxidative stress.

A simple and economic method to modify large organic surfaces for enhancing adhesion and transparent Au/PMMA with high electromagnetic shielding efficiency

This study introduces a simple and cost-effective approach for modifying large organic surfaces, facilitating robust adhesion between Au films and polymethyl methacrylate (PMMA) while retaining transparency to visible light and effectively shielding against electromagnetic interference (EMI). The proposed surface modification method employs a cheap low-power conventional UV lamp to illuminate organic surfaces in an open environment, rending it convenient and applicable for surfaces ranging from small to massive, irrespective of size, shape and location. By subjecting transparent PMMA glass to a brief 20–30 min exposure to a 36 W UV lamp positioned 5 cm away from the sample surface, the PMMA surface is dramatically modified and the surface is turned from hydrophobic to hydrophilic, establishing a strong adhesion between PMMA and Au films. The resulting Au/PMMA glass exhibits remarkable transparency about 70% within the visible light spectrum, coupled with an impressive EMI shielding efficiency that surpasses 20 dB across a broad range of electromagnetic wavebands, encompassing the S, C, X and Ku bands that correspond to the wave frequencies of major electromagnetic pollution and crucial applications of 5G communication, credit card validation, radar systems, traffic control, etc. Various characterizations have been conducted, elucidating the underlying mechanisms. This study presents an important advancement, and the accessible and scalable nature of the large-scalable surface modification method has far-reaching implications across numerous industrial sectors and applications, in addition to transparent EMI shielding Au/PMMA glasses.

Performance of reactive powder concrete with different fibres after high-temperature exposure

Reactive powder concrete (RPC) is used in structures such as radioactive storage plants, tall buildings and power plants. The performance of RPC after high-temperature exposure is therefore important. RPC (110 MPa) was prepared with different fibres (polypropylene fibres (PPF), polyester fibres (PEF) and their combination) at an optimum fibre dosage of 0.5% by weight of cement. The fibre-reinforced RPCs were exposed to temperatures of 200–800°C for different durations (30–120 min). Physical characteristics like colour change, fracture formation, weight loss, water absorption and residual compressive strength were evaluated. Ultrasonic pulse velocity tests were conducted. Scanning electron microscopy was used to observe the microstructure and assess the deterioration of hydrated substances after exposure to extreme temperatures for different durations. An increase in compressive strength was found for all fibre-reinforced RPCs after heating to 200°C for up to 120 min. The strength increased for 30-min exposure to 400°C. The strength of the fibre-reinforced RPCs decreased for all durations of 600°C and 800°C exposure. At these temperatures, the PEF-reinforced RPC had 10–15% greater residual strength than the RPCs. The PPF-reinforced RPC absorbed 6–12% more water than the RPCs made with PEF fibres after 120 min exposure to 800°C.

Production and characterization of rhamnolipids by Pseudomonas aeruginosa isolated in the Amazon region, and potential antiviral, antitumor, and antimicrobial activity

Biosurfactants encompass structurally and chemically diverse molecules with surface active properties, and a broad industrial deployment, including pharmaceuticals. The interest is growing mainly for the low toxicity, biodegradability, and production from renewable sources. In this work, the optimized biosurfactant production by Pseudomonas aeruginosa BM02, isolated from the soil of a mining area in the Brazilian Amazon region was assessed, in addition to its antiviral, antitumor, and antimicrobial activities. The optimal conditions for biosurfactant production were determined using a factorial design, which showed the best yield (2.28 mg/mL) at 25 °C, pH 5, and 1% glycerol. The biosurfactant obtained was characterized as a mixture of rhamnolipids with virucidal properties against Herpes Simplex Virus, Coronavirus, and Respiratory Syncytial Virus, in addition to antimicrobial properties against Gram-positive bacteria (Staphylococcus aureus and Enterococcus faecium), at 50 µg/mL. The antitumor activity of BS (12.5 µg/mL) was also demonstrated, with potential selectivity in reducing the proliferation of breast tumor cells, after 1 min of exposure. These results demonstrate the importance of studying the interconnection between cultivation conditions and properties of industrially important compounds, such as rhamnolipid-type biosurfactant from P. aeruginosa BM02, a promising and sustainable alternative in the development of new antiviral, antitumor, and antimicrobial prototypes.

Endophytic Aspergillus hiratsukae mediated biosynthesis of silver nanoparticles and their antimicrobial and photocatalytic activities.

In the current study, endophytic Aspergillus hiratsukae was used for the biosynthesis of silver nanoparticles (Ag-NPs) for the first time. The characterizations were performed using X ray diffraction (XRD), Transmission electron microscopy (TEM), Scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), Dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FT-IR), and UV-Vis spectroscopy. The obtained results demonstrated the successful formation of crystalline, spherical Ag-NPs with particle diameters ranging from 16 to 31 nm. The FT-IR studied and displayed the various functional groups involved, which played a role in capping and reducing agents for Ag-NPs production. The SEM-EDX revealed that the main constituent of the AS-formed sample was primarily Ag, with a weight percentage of 64.2%. The mycosynthesized Ag-NPs were assessed for antimicrobial as well as photocatalytic activities. The antimicrobial results indicated that the synthesized Ag-NPs possess notable antibacterial efficacy against Staphylococcus aureus, Bacillus subtilis, and Escherichia coli, with minimum inhibitory concentrations (MICs) of Ag-NPs ranging from 62.5 to 250 μg/mL. Moreover, the biosynthesized Ag-NPs demonstrated weak antifungal activity against Aspergillus brasiliensis and Candida albicans, with MICs of 500 and 1,000 μg/mL, respectively. In addition, the mycosynthesized Ag-NPs exhibited photocatalytic activity toward acid black 2 (nigrosine) dye under both light and dark stimulation. Notably, After 300 min exposure to light, the nigrosine dye was degraded by 93%. In contrast, 51% degradation was observed after 300 min in darkness. In conclusion, Ag-NPs were successfully biosynthesized using endophytic A. hiratsukae and also exhibited antimicrobial and photocatalytic activities that can be used in environmental applications.

Assessment of emissions and potential occupational exposure to carbon monoxide during biowaste composting.

To date, only a few studies focused on the carbon monoxide (CO) production during waste composting; all targeted on CO inside piles. Here, the CO net emissions from compost piles and the assessment of worker's occupational risk of exposure to CO at large-scale composting plants are shown for the first time. CO net emissions were measured at two plants processing green waste, sewage sludge, or undersize fraction of municipal solid waste. Effects of the location of piles (hermetised hall vs. open yard) and turning (before vs. after) were studied. Higher CO net emission rates were observed from piles located in a closed hall. The average CO flux before turning was 23.25 and 0.60 mg‧m-2‧h-1 for hermetised and open piles, respectively, while after- 69.38 and 5.11 mg‧m-2‧h-1. The maximum CO net emissions occurred after the compost was turned (1.7x to 13.7x higher than before turning). The top sections of hermetised piles had greater CO emissions compared to sides. Additionally, 5% of measurement points of hermetised piles switched to 'CO sinks'. The 1-h concentration in hermetised composting hall can reach max. ~50 mg CO∙m-3 before turning, and >115 mg CO∙m-3 after, exceeding the WHO thresholds for a 1-h and 15-min exposures, respectively.

Successful vitrification of equine embryos >300 microns without puncture or aspiration.

Equine embryos >300 μm require puncture before vitrification. Protocols that do not require pre-puncture would make vitrification easier and allow for its widespread use. To design a successful vitrification protocol for embryos >300 μm without puncture as a pre-treatment. Experimental in vivo study. Thirty-eight embryos were divided into 3 groups (G1: ≤300 μm, n = 11; G2: >300-500 μm, n = 20; G3: >500 μm, n = 7). Embryos were vitrified using a human vitrification kit. Following a 15 min exposure to equilibration solution (ES; 7.5% DMSO +7.5% ethylene glycol [EG] in a base medium [BM] of M199 HEPES-buffered medium [H199] + hydroxypropyl cellulose + gentamycin), embryos were exposed for ≤90 s to a vitrification solution (15% DMSO +15% EG + 0.5 M trelahose in BM), loaded onto a Cryolock and plunged into LN2. Warming was undertaken by plunging the Cryolock tip into 1 mL of H199 + 20% FBS + pen/strep +1 M sucrose at 42°C for 1 min. The embryos were then moved to a 0.5 M sucrose solution for 4 min, then placed in Vigro Hold for 4 min prior to transfer to a recipient. Pregnancy rates were 81.8% (9/11) for G1, 80% (16/20) for G2, and 0% (0/7) for G3. The largest embryo to survive was 480 μm. Limited numbers and only one pregnancy was followed to term. Equine embryos ≤480 μm can be successfully vitrified using a protocol with a longer exposure time to the ES. This does not appear to have a negative effect on early embryonic development.

UV-activated semiconductor gas sensor response measurement for formaldehyde detection

The gas sensing characteristics of ultraviolet light-emitting diodes (UV-LEDs)-activated semiconductor sensors were investigated to detect formaldehyde (HCHO) as a model volatile organic compound (VOC). As the major drawback of formaldehyde gas sensors is the low durability of the sensing material, efforts were made to establish a suitable metal oxide semiconductor and to enhance its stability throughout the sensing process. In2O3 nanoparticles (NPs) as the sensing material showed restructuring caused by exposure to different concentrations of formaldehyde in the presence of UV radiation when its morphology and structure were analyzed. UV radiation in the presence of formaldehyde was found to play a critical role in nanoparticles agglomeration, as well as its response inconsistency and instability.The novel method of measuring UV radiation elimination in the initial stages of the response curve was deemed effective for sensing layer preservation in this study. The scanning electron microscopy (SEM) results showed that this approach prevented any notable deformation in the nanoparticles’ shape and size and resulted in reproducible responses to various formaldehyde concentrations (10–50 ppm) in the steady-state and transient (5 min exposure) phases of the response curve. Hence, a short-time UV exposure has the potential to be applied in practical gas sensing applications in which the sensor can be automatically turned off a few minutes after any target gas detection. The gas sensor response slope in the transient phase of the response curve was found to be a very good indicator of target gas concentration and to obtain fast and consistent results while preserving the sensing material from restructuring. The findings of this study can be incorporated into the development of UV-LED-activated gas sensors where stable and fast response measurements of VOCs are required.

Biogenic synthesis, characterization and photocatalytic activity of cerium nanoparticles for treatment of dyes contaminated water

In this study, Murraya Koenigii leaf extract mediated cerium oxide nanoparticles (Ce-NPs) were synthesized using an eco-friendly approach. The surface morphology, elemental composition, surface functional groups, crystal structure and thermal stability of the synthesized Ce-NPs were examined using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-Ray diffraction (XRD) and thermogravimetric (TGA) analysis. The synthesized Ce-NPs were evaluated for their photocatalytic activity with respect to degradation of methylene blue dye (MBD) and acid orange-7 dye (AO7D) aqueous solution in the presence of sunlight. The dye degradation activity of the developed Ce-NPs was analyzed by the analysis of absorbance in treated and untreated aqueous dyes solution using UV–Vis spectrophotometer. The result of the study inferred that Ce-NPs have promising photocatalytic degradation ability (>98 %) for both AO7D and MBD (concentration = 10 mg L−1 of each dye) within 100 min exposure to sunlight.

Light stimulation of mitochondria reduces blood glucose levels.

Mitochondria regulate metabolism, but solar light influences its rate. Photobiomodulation (PBM) with red light (670 nm) increases mitochondrial membrane potentials and adenosine triphosphate production and may increase glucose demand. Here we show, with a glucose tolerance test, that PBM of normal subjects significantly reduces blood sugar levels. A 15 min exposure to 670 nm light reduced the degree of blood glucose elevation following glucose intake by 27.7%, integrated over 2 h after the glucose challenge. Maximum glucose spiking was reduced by 7.5%. Consequently, PBM with 670 nm light can be used to reduce blood glucose spikes following meals. This intervention may reduce damaging fluctuations of blood glucose on the body.

In vitro effects of different ozone preparations on microorganisms responsible for endometritis in the mare

Infectious endometritis is considered one of the major causes of infertility and it can affect up to 60% of barren mares. It is characterized by the presence of one or more microorganisms in the reproductive tract and it is treated with the administration of antibiotics, ecbolic agents and uterine lavages. Ozone, thanks to its antimicrobial properties that are based on its high oxidative potential, could represent an effective alternative treatment for endometritis. The aim of this study was to test in vitro the bactericidal and fungicidal properties of different ozone formulations, either as gas (experiment 1) or dissolved in two liquid matrices (experiment 2), specifically distilled water or oil (Neozone 4000, Cosmoproject, Parma, Italy), onto 6 different species of microorganisms isolated from mares with clinical endometritis, namely Escherichia coli, Staphylococcus aureus, Streptococcus equi subsp. Zooepidemicus, Pseudomonas aeruginosa, Klebsiella pneumoniae and Candida albicans. In the first experiment, 3 clinical antibiotic-resistant strains per each species were exposed to different conditions: to O2O3 gas mixtures (15 and 40 μg/ml for 1, 3 and 5 min), to 100 % O2 or left untreated. The results showed a reduction of the microbial count of over 99,9% for every pathogen, time and concentration of O2O3 gas mixtures tested. Furthermore, gaseous ozone showed both a time-dependant effect (5 vs 3 vs 1 min of exposure) and a concentration-dependant effect (40 vs 15 μg/ml) at 1 and 3 min, while after 5 min no differences were observed. In the second experiment, minimum inhibitory concentration (MIC), and minimum bactericidal/fungicidal concentration (MBC, MFC) of ozonated distilled water and ozonated oil were evaluated. Ozonated oil showed a bactericidal/fungicidal activity against all the strains tested (MIC range 12.5–25 % v/v, MBC/MFC range 12.5–50 % v/v) while ozonated distilled water didn't show an observable antimicrobial effect, discouraging its use as an antimicrobial agent for the treatment of endometritis.The results of this in vitro study indicate that both gaseous ozone and ozonated oil exerted remarkable antimicrobial activities and are promising alternative treatments for infectious endometritis, even when caused by antibiotic-resistant bacteria, and encourage further experiments in an effort to scale down or even prevent the use of antibiotics in equine reproduction.