Effect Of Air Exposure Research Articles

Anesthetic sampling and the tissue regeneration potential of oysters: A study with Crassostrea hongkongensis

The use of an appropriate amount of anesthetic can prevent the sacrifice of oysters during experimental sampling or seedling rearing. In this study, we assessed the effects of air exposure and three concentrations of magnesium chloride (10, 40, and 70 g L–1) on the anesthetic efficiency for Crassostrea hongkongensis. We examined the recuperative capacity of the oysters post-tissue sampling. The results indicated that 36 h of air exposure could significantly enhance the anesthetic efficiency of C. hongkongensis while ensuring the oysters’ survival. A 40 g L–1 solution of magnesium chloride had the optimal anesthetic effect on C. hongkongensis across all oyster sizes. In addition, smaller oysters (119.10 g) had a higher relaxation rate than larger oysters (191.00 g). The oysters anesthetized with 40 g L–1 magnesium chloride also demonstrated the best recovery. No deaths were observed among the non-anesthetized oysters, anesthetized-recovered oysters, or non-recovered oysters during a seven-day post-farming period. In terms of live sampling, the control group (100 %), gonad group (100 %), mantle group (98.67 %), gill group (89.33 %), and adductor muscle group (97.33 %) all showed high survival rates after anesthesia. Observation of tissue growth post-sampling revealed the presence of focal green areas in tissues between days 7 and 14. By day 30, the adductor muscle and mantle tissues had fully healed, and the regrown tissue in the gills had approached its original length. A 40 g L–1 magnesium chloride solution had no significant effects on gametes in terms of fertilization rate, growth rate, and attachment rate. The present findings indicated that C. hongkongensis could be effectively anesthetized using a 40 g L–1 magnesium chloride solution following 36 h of aerial exposure. Post-anesthesia tissue and gamete sampling did not result in significant mortality, and the tissues had fully recovered within 30 days post-sampling. The anesthesia did not have any adverse effects on the progeny.

Effects of water immersion on immune, intestinal flora and metabolome of Chinese mitten crab (Eriocheir sinensis) after air exposure

Air exposure stress can induce stress response of Eriocheir sinensis and affect its normal life activities. The goal of this study was to investigate the effects of water immersion on the recovery of hepatopancreas immune-related enzyme activity, intestinal microbial diversity and metabolic level of Chinese mitten crabs after exposure to air. The results show that immersion can effectively alleviate the adverse effects of air exposure on the antioxidant capacity and immune capacity of Chinese mitten crabs, and the longer the time of immersion, the more obvious the recovery effect. Among them, the levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase and acid phosphatase significantly increased after exposure to air (P < 0.05), reached a peak at 3 h, began to decline after immersion, and returned to a level close to the initial value at 24 h (P < 0.05). In addition, after exposure to air, the glucose and total cholesterol in haemolymph of Eriocheir sinensis were significantly different from the initial values (P < 0.05), gradually recovered to the initial level after re-immersion. However, changes in intestinal flora and hepatopancreas metabolism caused by air exposure did not fully recover after water exposure, and its negative effects did not completely disappear. The sequencing results showed that the species composition and diversity of intestinal microorganisms of Chinese mitten crab changed after air exposure and immersion treatment. The relative abundance of Actinomycetes increased significantly, while that of Proteobacteria and Firmicutes decreased significantly. Metabolomics analysis showed that air exposure and immersion destroyed the metabolic balance of amino acids and carnitine, reduced the level of carnitine metabolism, hindered the absorption of nutrients, and led to the accumulation of harmful substances.

Effects of L-NAME and air exposure on mitochondrial energetic markers, thyroid hormone receptor/regulator system and stress/ease-responsive receptor expression in the brain/gut axis of zebrafish

As a signal molecule, nitric oxide (NO) has several physiological actions in fish. However, the action of NO on the brain/gut axis, a classic inter-organal axis that bridges the gastrointestinal tract and the CNS, still requires more understanding. The short-term in vivo action of a NO inhibitor, N-omega-nitro-L-arginine methyl ester (L-NAME), on mitochondrial energetic markers and the receptor expression of thyroid hormone (TH) and neuroendocrine hormones involved in stress/ease response was tested in the brain/gut axis of zebrafish exposed to either in non-stressed or air-exposed condition. L-NAME treatment decreased the NO content in brain and gut segments in non-stressed fish but rose upon L-NAME treatment in air-exposed fish that corresponded with the activation of inos, nnos, hif1a and hif1an transcript expressions. The brain/gut segments that showed spatial and differential sensitivity to L-NAME, modified the transcript expression patterns of stress (adra2da, adrb1, nr3c2)- and ease-responsive (htr2b, slc6a4a, mtnr1aa) hormone receptors. The expression pattern of the TH receptor/regulator system (thra, thrb, dio1, dio2, dio3) becomes more active in gut segments than brain segments upon L-NAME challenge in stressed zebrafish. The data provide evidence for a novel role of NO as an integrator of brain/gut axis segments in zebrafish, where the endogenously produced NO in mid-brain/posterior-gut axis aligns together upon air-exposure stress, providing a lead role to the posterior gut that activates and directs the neuroendocrine receptor expressions of stress/ease responsive genes. The data further invites studies exploring the therapeutic potential of L-NAME in this biomedical model to control the brain/gut axis segments.

EVALUATION OF THE EFFECT OF AIR ON THE HYDRATION SYSTEM OF THE AXIAL PISTONS

This study investigates the effect of air exposure on the hydration system of axial pistons, critical components in various hydraulic systems. The hydration process, which is integral to the functionality and longevity of axial pistons, is potentially sensitive to environmental factors such as air. This research aims to elucidate the effect of air on the hydration kinetics, surface properties and performance of axial pistons. Experimental studies were conducted using controlled environments to analyze the hydration behavior of piston samples under varying degrees of air exposure. Techniques such as surface microscopy, chemical analysis and mechanical testing were used to comprehensively evaluate the effects. Preliminary findings indicate that exposure to air significantly affects the hydration kinetics of axial pistons, affecting the rate and extent of hydration. Surface analysis reveals changes in surface morphology and chemical composition indicating changes in the air-induced hydration process. Moreover, mechanical testing reveals notable differences in the performance characteristics, including wear resistance and friction properties, of pistons exposed to varying weather environments. Overall, this study underlines the importance of considering air exposure in understanding and optimizing the hydration system of axial pistons and provides valuable information for improving hydraulic system efficiency and reliability. Keywords: axial pistons, hydration system, piston, hydraulic machine, rotor.

Fruit encasing preserves the dispersal potential and viability of stranded Posidonia oceanica seeds

Posidonia oceanica meadows are the most productive coastal ecosystem in the Mediterranean. Posidonia oceanica seeds are enclosed in buoyant fleshy fruits that allow dispersal. Many fruits eventually strand on beaches, imposing a remarkable energy cost for the plant. This study aims to assess whether stranded seeds retain functional reproductive potential under a variety of environmental conditions. First, we measured the possibility that seeds could be returned to the sea, by tagging fruits and seeds. Second, we quantified the effect of air, sun and heat exposure on the viability and fitness of stranded fruits and naked seeds. The results showed that on average more than half of fruits and seeds are returned to the sea after stranding events and that fruits significantly protect from desiccation and loss of viability. Furthermore, in fruits exposed to the sun and in naked seeds, seedlings development was slower. This study indicates that a significant portion of stranded P. oceanica fruits have a second chance to recruit and develop into young seedlings, relieving the paradox of large energy investment in seed production and apparent low recruitment rate. Additionally, we provide practical indications for seed collection aimed at maximizing seedling production, useful in meadow restoration campaigns.

Changes in chemical composition and fermentation profile in silages from rehydrated grains of maize hybrids during prolonged air exposure

Most studies investigated the effects of air exposure during the ensiling of whole maize silage and high-moisture maize grains on the chemical composition and fermentation profile, but not of rehydrated grain. The aim of the present study was to investigate the effect of the hybrid and the duration of air exposure on the pH and the content of moisture, main nutrients, fermentation products and nitrogen fractions in silages from three commercial maize hybrids. The grains were rehydrated to 32 % of moisture and ensiled for 63 days with the addition of an inoculant (BIO-SIL®, Dr Pieper Technologie und Produktentwicklung GmbH). After opening, the silages were stored at room temperature for 10 days and samples were taken after 0, 1, 3, 5 and 10 days of air exposure. With increasing duration of air exposure, the content of moisture, lactic and acetic acid and ethanol decreased, while the pH value and the content of water-soluble carbohydrates and ammonia increased. The hybrid affected all the determined properties of the silages except the pH and the ethanol content. There were distinct differences in the contents of moisture, total sugars, water-soluble carbohydrates, lactic, acetic, propionic and isobutyric acids, methanol and ammonia, suggesting that some hybrids may be more susceptible to aerobic spoilage. The majority of the properties remained similar until the fifth day of air exposure, suggesting that the silages of all three hybrids were stable during this period. The only property that increased immediately after air exposure was the content of nitrogen fractions suggesting that proteolysis was occurring, even though pH and lactic acid content remained unchanged. Overall, the results of the study indicate that the behaviour of rehydrated maize silage after exposure to air should be taken into account when selecting maize hybrids.

A Guide for the Electrochemical Stability of Thiolate Self-Assembled Monolayers on Gold in Various Electrolytes

Self-assembled monolayers (SAMs) are widely used in surface chemistry to modify surfaces for various applications such as biosensing1, electronics2, and electrocatalysis3. SAMs are attractive due to their high surface coverage and stability. Although studies have been conducted to test the effects of temperature, air exposure, and solvent degradation on SAMs stability 4,5, the electrochemical stability of SAMs has not been as extensively studied. Existing literature on this topic mainly focuses on the reductive desorption limits of thiolate SAMs in alkaline conditions6,7. Recent work by Ramos et al. demonstrated pH-dependent stable potential windows in which SAMs remained intact on electrode surfaces of different metals8. However, there is still a need to verify and expand on this work.To address this need, we aim to create a comprehensive guide on the electrochemical stability of thiolate SAMs on gold electrodes. We will use cyclic voltammograms (CV), electrochemical impedance spectroscopy (EIS), and electrochemical surface plasmon resonance (EC-SPR) to probe and verify the stable electrochemical potential windows in both aqueous and non-aqueous electrolytes. We have conducted studies on three aqueous solutions at three distinct pH, perchloric acid, potassium hydroxide, and sodium chloride. For non-aqueous solvents we tested a wide range of different organic solvents including acetonitrile, dimethylformamide, propylene carbonate, and various alcohols. Our findings demonstrate that the main factor for SAM stability in aqueous and non-aqueous electrolytes is the pH and solubility of the SAM, respectively. Our poster will present our current work and outlook on this topic.(1) Dauphin-Ducharme, P.; Ploense, K. L.; Arroyo-Currás, N.; Kippin, T. E.; Plaxco, K. W. Electrochemical Aptamer-Based Sensors: A Platform Approach to High-Frequency Molecular Monitoring In Situ in the Living Body. In Biomedical Engineering Technologies: Volume 1; Ossandon, M. R., Baker, H., Rasooly, A., Eds.; Methods in Molecular Biology; Springer US: New York, NY, 2022; pp 479–492. https://doi.org/10.1007/978-1-0716-1803-5_25.(2) Hatton, R. A.; Willis, M. R.; Chesters, M. A.; Rutten, F. J. M.; Briggs, D. Enhanced Hole Injection in Organic Light-Emitting Diodes Using a SAM-Derivatised Ultra-Thin Gold Anode Supported on ITO Glass. J. Mater. Chem. 2003, 13 (1), 38–43. https://doi.org/10.1039/B208169P.(3) Shang, H.; Wallentine, S. K.; Hofmann, D. M.; Zhu, Q.; Murphy, C. J.; Baker, L. R. Effect of Surface Ligands on Gold Nanocatalysts for CO2 Reduction. Chem. Sci. 2020, 11 (45), 12298–12306. https://doi.org/10.1039/D0SC05089J.(4) Schlenoff, J. B.; Li, M.; Ly, H. Stability and Self-Exchange in Alkanethiol Monolayers. J. Am. Chem. Soc. 1995, 117 (50), 12528–12536. https://doi.org/10.1021/ja00155a016.(5) Laibinis, P. E.; Whitesides, G. M. Self-Assembled Monolayers of n-Alkanethiolates on Copper Are Barrier Films That Protect the Metal against Oxidation by Air. J. Am. Chem. Soc. 1992, 114 (23), 9022–9028. https://doi.org/10.1021/ja00049a038.(6) Salvarezza, R. C.; Carro, P. The Electrochemical Stability of Thiols on Gold Surfaces. J. Electroanal. Chem. 2018, 819, 234–239. https://doi.org/10.1016/j.jelechem.2017.10.046.(7) Beulen, M. W. J.; Kastenberg, M. I.; van Veggel, F. C. J. M.; Reinhoudt, D. N. Electrochemical Stability of Self-Assembled Monolayers on Gold. Langmuir 1998, 14 (26), 7463–7467. https://doi.org/10.1021/la981031z.(8) Ramos, N.; Medlin, J. W.; Holewinski, A. Electrochemical Stability of Thiolate Self-Assembled Monolayers on Au, Pt, and Cu; preprint; Chemistry, 2022. https://doi.org/10.26434/chemrxiv-2022-dt7dk. Figure 1

Effect of temperature, air exposure and gas mixture on Pd82–Ag15–Y3 membrane for hydrogen separation

Material characterization, hydrogen permeation, and separation properties of a novel ternary Pd82Ag15Y3 membrane were evaluated by feeding single gases and several mixtures at temperature and pressure ranges of 300–600 °C and 1.0–3.0 bar (abs), respectively. The Pd82–Ag15–Y3 membrane was prepared by cold rolling and was characterized by ∼38 μm of thickness. When exposed to air at different temperature and constant pressure of 1 bar, the membrane showed good thermal and chemical stability. In particular, its surface area increased from 615 μm2 at 25 °C to 685 μm2 at 500 °C indicating a potential improvement of hydrogen permeation. However, several agglomerates consisting of metal oxides were formed on the surface at the highest temperature. The temperature was -then- kept constant at 400 °C and the pressure was varied to analyze the effects of singles gases and several mixtures on the hydrogen permeation characteristics. When exposed to pure gases, such as H2 and N2, the membrane showed an H2 permeability of 9.1 × 10−11 mol m−1 s−1.Pa−0.9 and “n” value of 0.9 due to the presence of Y, while no N2 was detected in the permeate stream, respectively. So, the membrane was considered to be completely selective towards H2 permeation. When mixtures were used, the hydrogen permeation decreased by its original value due to the presence of other gases, such as N2, CH4, CO2 and CO. The presence of CO particularly affected the H2 permeating flux due to the competitive adsorption of both gases on the Pd-alloy surface. Finally, the Scanning Electron Microscope (SEM), Energy Dispersive X-Ray Spectroscopy (EDS), Atomic Force Microscope (AFM) and X-ray diffraction (XRD) analysis were performed to observe any changes in the surface and structure of pristine and used membrane.

The Effect of Air Exposure on the Hydrogenation Properties of 2Mg-Fe Composite after Mechanical Alloying and Accumulative Roll Bonding (ARB)

In this study, we successfully obtained a 2Mg-Fe mixture through mechanical alloying (MA) and processed it via accumulative roll bonding (ARB) (MA+ARB). Our primary focus was to analyze the impact of ambient air exposure while also evaluating the processing route. Some powder samples were exposed to air for 12 months (stored in a glass desiccator with an average yearly temperature and relative humidity of ~27 °C and 50.5%) before undergoing ARB processing. The Mg samples obtained after ARB processing exhibited a (002)-type texture. Our results demonstrate that all samples, including those processed via ARB, could rapidly absorb hydrogen within a matter of minutes despite considerable differences in surface area between powders and rolled samples. Grain size reduction by MA and ARB processing and texturing may have influenced this behavior. ARB-processed samples reached approximately 60% (~1.8 wt.%) of their maximum acquired capacity within just 24 min compared to powders (~2.2 wt.%) stored for a year, which took 36 min. In addition, the desorption temperatures (~300 °C) were lower than those of MgH2 (~434 °C). The absorption and desorption kinetics remained fast, even after prolonged exposure to air. Although there were minor variations in capacities, our overall findings are promising since scalable techniques such as ARB have the potential to produce hydrogen storage materials that are both safe and cost-effective in a highly competitive market.

Reliable p-type organic permeable base transistors—the missing component for integrated circuits

Due to their nm-range channel length, vertical organic transistors are gaining scientific interest to overcome the frequency limitations of lateral organic transistor. Especially, vertical organic permeable base transistors (OPBTs) with a structure resembling a vacuum-tube-triode stand out due to their excellent electrical performance. Recently, n-type OPBTs have been demonstrated with excellent performance and great potential to be applied in high-frequency logic circuits, display driving circuits, and light-emitting devices. However, achieving adequate p-type OPBTs to catch up with the performance of n-type devices is still challenging. Here, we report on the peculiar finding that the extended exposure of p-type OPBTs to ambient air during the fabrication has a positive effect on the electrical performance and tremendously improves the yield of devices to . Upon exposing the fresh device to air, oxygen diffuses into the semiconductor layer interacting with the base electrode, which facilitates the formation of pinholes in the base and creates an insulator layer around the base. Moreover, as oxygen acts as a p-dopants to the p-type semiconductors used in this work, the device performance is further improved, manifesting in an increased on-state current. However, as the exposure time increases, different p-type organic semiconductors show different behavior depending on their ionization potential. Comparing two semiconductor materials with a difference in their ionization potential of 0.4 eV, we show that long-term degradation could be effectively suppressed. Therefore, the positive effect of air exposure could be utilized to optimize p-type OPBTs, which offers a simple and universal way to construct high performance p-type OPBTs and possibly also complementary circuits.

Scratching and Stretching the Shrunken Cranial Dura for Primary Closure.

At craniotomy, the dura shrinks due to the drying effect of illumination and air exposure, rendering its primary closure difficult. When the opening is narrow, it can be patched with autologous grafts. However, tissue harvesting and meticulous suturing take time. As the cost-effectiveness of using dural substitutes is poor, we developed a new technique that involves dural scratching for the primary closure of dural openings. We applied our technique because in 53 adults who underwent supratentorial craniotomy we encountered difficulties with the primary closure of a dural opening 5mm or less in width. With a scalpel, we placed several fine scratches parallel to the edge of the opening on the surface of the dura, taking care not to perforate the deep layer. This relieved dural tension and the tissue was stretched enough to permit closing with sutures. Our technique achieved primary dural closure in 46 of 53 patients (87%) who primarily had undergone narrow supratentorial craniotomies. The other 7 additionally required small autologous grafts to patch narrow residual openings at the intersection of the durotomy. There were no procedure-related complications such as cerebrospinal fluid leakage and persistent headache due to tension of the closed dura. Dural scratching is simple, safe, requires no special instrumentation, facilitates primary closure of the shrunken dura by stretching, and reduces the need for patch grafting.

Effect of Air Exposure on Electron-Beam-Induced Degradation of Perovskite Films.

Organic-inorganic halide perovskites are interesting candidates for solar cell and optoelectronic applications owing to their advantageous properties such as a tunable band gap, low material cost, and high charge carrier mobilities. Despite making significant progress, concerns about material stability continue to impede the commercialization of perovskite-based technology. In this article, we investigate the impact of environmental parameters on the alteration of structural properties of MAPbI3 (CH3NH3PbI3) thin films using microscopy techniques. These characterizations are performed on MAPbI3 thin films exposed to air, nitrogen, and vacuum environments, the latter being possible by using dedicated air-free transfer setups, after their fabrication into a nitrogen-filled glovebox. We observed that even less than 3 min of air exposure increases the sensitivity to electron beam deterioration and modifies the structural transformation pathway as compared to MAPbI3 thin films which are not exposed to air. Similarly, the time evolution of the optical responses and the defect formation of both air-exposed and non-air-exposed MAPbI3 thin films are measured by time-resolved photoluminescence. The formation of defects in the air-exposed MAPbI3 thin films is first observed by optical techniques at longer timescales, while structural modifications are observed by transmission electron microscopy (TEM) measurements and supported by X-ray photoelectron spectroscopy (XPS) measurements. Based on the complementarity of TEM, XPS, and time-resolved optical measurements, we propose two different degradation mechanism pathways for air-exposed and non-air-exposed MAPbI3 thin films. We find that when exposed to air, the crystalline structure of MAPbI3 shows gradual evolution from its initial tetragonal MAPbI3 structure to PbI2 through three different stages. No significant structural changes over time from the initial structure are observed for the MAPbI3 thin films which are not exposed to air.

Functional and Behavioral Trade-Offs between Terrestrial and Aquatic Locomotion in the Amphibious Fish Kryptolebias marmoratus.

The mangrove rivulus (Kryptolebias marmoratus) is a phenotypically plastic teleost fish that can spend considerable time on land and traverse the terrestrial realm through a behavior termed the tail-flip jump. The tail-flip jump is a transitional stage between fully aquatic and terrestrial lifestyles. Therefore, understanding this behavior can provide insight into how organisms adapt to new environments over evolutionary time. Studies of K. marmoratus show that terrestrial acclimation and exercise improve tail-flip jumping performance due to muscle remodeling, but the implications of these muscular changes on aquatic locomotion are unknown. In the present study, we hypothesized that (1) terrestrial acclimation and exercise lead to physiological changes, such as changes to muscle fiber type, muscle mass distribution, or body shape, that optimize tail-flip jump distance and endurance while negatively impacting swimming performance in K. marmoratus, and (2) plasticity of the brain (which has been demonstrated in response to a variety of stimuli in K. marmoratus) allows terrestrial emersion and exercise to cause behavioral changes that promote survival and long-term reproductive success. To test these hypotheses, we measured the critical swimming speed (Ucrit), tail-flip jump distance, terrestrial endurance, and undisturbed aquatic behavior of age- and size-matched K. marmoratus before and after a terrestrial exercise period. This period consisted of six 3-min exercise sessions spread over 12 days, during which the fish were prompted to jump continuously. To isolate the effects of air exposure, a separate group was exposed to air for an equivalent period but not allowed to jump. Air exposure improved maximum jump distance but negatively affected swimming performance (Ucrit). Terrestrial endurance (number of jumps) improved in the exercised group, but Ucrit showed no significant change. Contrary to our first hypothesis, a trade-off exists between jump distance and Ucrit but not between jump endurance and Ucrit. Exercised individuals were more active following exercise, resulting either from the onset of dispersion behavior or a heightened stress response.

The effect of air exposure and re-water on gill microstructure and molecular regulation of Pacific white shrimp Penaeus vannamei

The Penaeus vannamei is an important shrimp species with enormous commercial and ecological values. In production process, the air exposure resistance is vital for live transportation without water. We tested the air exposure resistant ability of P. vannamei, and carried out gill histological observation and gene expression analysis. The physiology and molecular response to the air exposure stress of P. vannamei was revealed. We found that body weight could affect the air exposure tolerance. Air exposure caused epithelial cell of gill filament shrinking and tissue fluid exudation within half of hour, and triggered oxidative stress response. After retrieved to water, epithelial cell shrinking and tissue fluid exudation recovered gradually, but oxidative and antioxidant response is still going on. Organisms reduced oxidative stress by regulating levels of antioxidants and antioxidant enzymes that remove reactive oxygen species (ROS) and RNA and DNA processing to repair tissue damage, and expression of apoptosis associated-genes altered. Furthermore, the survive shrimps could live steadily more than 5 days, and their gill filament recovered to normal state, proving that the damage of air exposure is reversible. These findings could be considered in the waterless live transportation of P. vannamei.

Effects of short-term waterfall forest aerosol air exposure on rat lung proteomics

Chronic exposure to airborne microparticles has been shown to increase the incidence of several chronic diseases. Previous studies have found that waterfall forest aerosols contribute to a diminished immune stress response in patients with asthma. However, the specific effects of short-term waterfall forest aerosol exposure on lung proteins have not been fully elucidated. This study used liquid chromatography-tandem mass spectrometry (LC-MS) to analyze changes in protein expression in the lungs of rats exposed to short-term waterfall forest aerosol environments. Specific protein markers were identified using bioconductivity analysis screening and validated using immunohistochemistry. Waterfall forest aerosol environment exposure on day 5 downregulated the expression of the classical inflammatory pathway nuclear factor κB (NF-κB) signaling pathway. As the waterfall forest aerosol environment increased due to the duration of exposure, it was involved in oxidative phosphorylation and then hormone signaling in lung cells from the very beginning. In contrast, at day 15 of exposure, there is an effect on the regulation of the immune-related high-affinity IgE receptor pathway. In addition, iron-sulfur Rieske protein (Uqcrfs1), mitochondrial Tu translation elongation factor (Tufm) and ribosomal protein L4 (Rpl4) were identified as possible bioindicators for the evaluation of air quality. These results provide a comprehensive proteomic analysis that supports the positive contribution of a good air quality environment to lung health.

Modeling Preclinical Cancer Studies under Physioxia to Enhance Clinical Translation.

Oxygen (O2) plays a key role in cellular homeostasis. O2 levels are tightly regulated in vivo such that each tissue receives an optimal amount to maintain physiologic status. Physiologic O2 levels in various organs range between 2% and 9% in vivo, with the highest levels of 9% in the kidneys and the lowest of 0.5% in parts of the brain. This physiologic range of O2 tensions is disrupted in pathologic conditions such as cancer, where it can reach as low as 0.5%. Regardless of the state, O2 tension in vivo is maintained at significantly lower levels than ambient O2, which is approximately 21%. Yet, routine in vitro cellular manipulations are carried out in ambient air, regardless of whether or not they are eventually transferred to hypoxic conditions for subsequent studies. Even brief exposure of hematopoietic stem cells to ambient air can cause detrimental effects through a mechanism termed extraphysiologic oxygen shock/stress (EPHOSS), leading to reduced engraftment capabilities. Here, we provide an overview of the effects of ambient air exposure on stem and non-stem cell subtypes, with a focus on recent findings that reveal the impact of EPHOSS on cancer cells.

Effect of High-Temperature Air Exposure on the Microstructure and Mechanical Properties of β-Ti Honeycomb Sandwich Panels

Effect of High-Temperature Air Exposure on the Microstructure and Mechanical Properties of β-Ti Honeycomb Sandwich Panels

Synergistic effect of TiH2 and air exposure on enhancing hydrogen storage performance of Mg2NiH4

Air stability of magnesium-based hydrogen storage materials is one of the key challenges for its large-scale application, as the hydrides could be oxidized easily during air exposure. In this work, TiH2 and graphite were added into magnesium nickel hydride (Mg2NiH4) by short-time (0.5 h) mechanical milling to clarify the effect of air exposure on hydrogen storage behavior of the composites. Among the various Mg2NiH4–additive composites, the Mg2NiH4–TiH2 composite showed the highest hydrogen desorption and absorption capacity retention of 76.9 % and 75.6 % after air exposure for 30 days, respectively. It is worth noting that both the hydrogen absorption and desorption kinetics of the composites were enhanced after air exposure, especially for the Mg2NiH4 co-added with TiH2 and graphite composite. The excellent air stability and enhanced hydrogen reaction kinetics of Mg2NiH4–TiH2 composite should be attributed to the ternary-synergistic effect, including the protective effect of passivation layer, catalytic and sacrificial effect of TiH2, and catalysis of in-situ formed Ni-based products. They prevented further oxidation of the active matrix and provided more active sites for hydrogen absorption and desorption reactions. Our findings might guide the design and development of reversible metal hydrides with excellent reaction activity and air stability.

Effect of Air Exposure on the Acid–Base Balance of Hemolymph in Akoya Pearl Oyster Pinctada fucata martensii

The hemolymph acid–base status of Akoya pearl oyster Pinctada fucata martensii exposed to air at 20°C was investigated. Air-exposed Akoya pearl oyster showed a decrease in hemolymph pH from 7.568 to 6.825 after 24 h. The hemolymph total CO2 concentration increased from 2.25 mM/L to 4.50 mM/L during 24 h of air exposure. The hemolymph CO2 partial pressure (Pco2) was calculated by rearranging the Henderson–Hasselbalch equation. The hemolymph Pco2 increased from 1.0 torr to 14.8 torr, and bicarbonate ion concentration increased from 2.21 mM/L to 3.91 mM/L during 24 h of air exposure. The hemolymph calcium ion concentration ([Ca2+]) increased from 9.4 mM/L to 12.8 mM/L. These results indicated that Akoya pearl oysters showed hemolymph acidosis with partial metabolic compensation by mobilization of bicarbonate from the shell valve during prolonged air exposure. Immersion in seawater for between 4 h and 24 h decreased the effect of air exposure on hemolymph acid–base status, except for [Ca2+]. The hemolymph [Ca2+] of immersed Akoya pearl oysters was slightly higher than the initial level upon air exposure although hemolymph [Ca2+] had already decreased after immersion in seawater for 4 h and 24 h. The hemolymph acid–base balance of immersed Akoya pearl oysters recovered to the initial level after 4–24 h, even if the animals were exposed to the air for a prolonged time (24 h).

Effects of air exposure, time, temperature, and humidity on different serum electrolytes

Background: Pre-analytical, analytical, or post analytical variations can induce, change, or alter the tests results. Laboratory errors lead to unnecessary delays in test report and also increased costs by repeat samples which have become a pain to the patients. Aims and Objectives: The aims of this study were to determine alterations in the concentration of serum sodium (Na+), potassium (K+), and ionized calcium (Ca++) concentration with reference to air exposure, time, temperature, and humidity. Materials and Methods: Fifty samples as case and 50 samples as control were included from a normal healthy population in this study. After getting the samples, first readings were taken for case samples and were uncapped and the remaining samples were set aside capped at 24°C, 20% humidity for half an hour and followed by second reading which was taken. Results: Variation in the mean serum sodium between groups is 0.06 mEq/L (0.04%) and 0.08 mEq/L (0.07%) which is very negligible and insignificant (P &gt; 0.05). The mean level of serum K+ in cases is 4.35 mEq/L and in controls is 4.27 mEq/L. After half an hour, the mean level of serum K+ in cases is 4.51 mEq/L and, in controls, is 4.29 mEq/L. Hence, the variation in results in cases is 0.16 mEq/L (3.68%) and in controls is 0.02 mEq/L (0.47%) which is highly significant (P &lt; 0.05). The mean level of serum Ca++ in cases is 1.15 mmol/L and in controls is 1.17 mmol/L. After half an hour, the mean level of serum Ca++ in cases is 1.09 mmol/L and in controls is 1.16 mmol/L. Hence, the variation in results in cases is 0.06 mmol/L (5.22%) and in controls is 0.01 mmol/L (0.85%) which is highly significant (P &lt; 0.05). Conclusion: Air exposure significantly alters the serum K+ and Ca++ level, but the alteration in serum Na+ level is not significant.