Noble Gas Research Articles

Protective effects of mesenchymal stromal cell-derived secretome on dermonecrosis induced in rabbits by Loxosceles intermedia spider venom.

Loxoscelism refers to a set of clinical manifestations caused by the bite of spiders from the Loxosceles genus. The classic clinical symptoms are characterized by an intense inflammatory reaction at the bite site followed by local necrosis and can be classified as cutaneous loxoscelism. This cutaneous form presents difficult healing, and the proposed treatments are not specific or effective. This study aimed to evaluate the protective effect of mesenchymal stromal cells-derived secretome on dermonecrosis induced by Loxosceles intermedia spider venom in rabbits. Sixteen rabbits were distributed into four groups (n = 4). Except for group 1 (G1), which received only PBS, the other three groups (G2, G3, and G4) were initially challenged with 10 μg of L. intermedia venom, diluted in 100 μL of NaCl 0.9%, by intradermic injection in the interscapular region. Thirty minutes after the challenge all groups were treated with secretome, except for group 2. Group 1 (G1-control group) received intradermal injection (ID) of 60 μg of secretome in 0.15 M PBS; Group 2 (G2) received 0.9% NaCl via ID; Group 3 (G3) received 60 μg of secretome, via ID and Group 4 (G4), received 60 μg of secretome by intravenous route. Rabbits were evaluated daily and after 15 days were euthanized, necropsied and skin samples around the necrotic lesions were collected for histological analysis. Rabbits of G1 did not present edema, erythema, hemorrhagic halo, or necrosis. In animals from G2, G3, and G4, edema appeared after 6h. However, minor edema was observed in the animals of G2 and G3. Hemorrhagic halo was observed in animals, six hours and three days after, on G2, G3, and G4. Macroscopically, in G4, only one animal out of four had a lesion that evolved into a dermonecrotic wound. No changes were observed in the skin of the animals of G1, by microscopic evaluation. All animals challenged with L. intermedia venom showed similar alterations, such as necrosis and heterophilic infiltration. However, animals from G4 showed fibroblast activation, early development of connective tissue, neovascularization, and tissue re-epithelialization, indicating a more prominent healing process. These results suggest that secretome from mesenchymal stromal cells cultured in a xeno-free and human component-free culture media can be promising to treat dermonecrosis caused after Loxosceles spiders bite envenoming.

Effects of prebiotic (lactoferrin) and diclazuril on broiler chickens experimentally infected with Eimeria tenella.

Avian coccidiosis presents a significant challenge to the poultry industry in Egypt, highlighting the urgent need for validating new drug targets offering promising prospects for the development of advanced anticoccidials. Although numerous reports highlight the activity of lactoferrin (LF) against various microorganisms, its potential against Eimeria has not been explored. The present study evaluated the potential anticoccidial effect of LF and diclazuril in broiler chickens experimentally infected with Eimeria tenella. A total of 100 one-day-old broiler chicks were divided into five equal groups (20 each) as follows: Group 1 (G1) served as the normal healthy control group, Group 2 (G2) consisted of chickens infected with 1 × 105 sporulated E. tenella oocysts at 14 days of age, Group 3 (G3) comprised infected chickens treated with diclazuril (0.5 mL/L in drinking water) for 3 days successively, Group 4 (G4) included infected chickens treated with LF (at a dose of 250 mg/kg of diet) from one day of age until the end of the study, and Group 5 (G5) comprised infected chickens treated with both LF and diclazuril. The positive control group (G2) experienced significant reductions in body weight (BW), BW gain, serum glucose, lipase, amylase, total antioxidant capacity, several hematological indices, and total proteins, along with alterations in various antioxidant enzymes. Conversely, serum levels of aspartate aminotransferase (AST), Alanine aminotransferase (ALT), Alkaline phosphatases (ALP), urea, creatinine, nitric oxide, mean corpuscular volume (MCV), White blood cells (WBCs), heterophils, alpha 2, beta 1, and liver contents of malondialdehyde were elevated in this group. Moreover, higher oocyst counts and lesion scores, along with histopathological alterations, were observed in G2. Remarkably, treatment with diclazuril and/or LF demonstrated potent antioxidant and anticoccidial effects, resulting in reduced shedding of oocysts, lesion scores, and lymphocytic infiltrates in the cecum. Additionally, these treatments improved the antioxidant and immune systems in chickens and restored all histopathological changes reported in the infected non-treated group (G2). This study offers novel perspectives on the potential anticoccidial effects of the combination of LF and diclazuril in broiler chickens infected with E. tenella, highlighting the potential synergistic actions of LF in treating poultry coccidiosis.

Effect of wet feeding on performance, blood plasma indices, intestinal histomorphometry, and economics of broiler chickens under hot climatic conditions.

The study aimed to investigate the impact of wet feeding on broiler chicken performance and intestinal histomorphometry. The research was conducted at the Veterinary College, Udaipur, India, using 144 commercial broiler chicks from day 1 to 6 weeks of age. The chicks were divided randomly into three experimental groups, each with four replicates comprising 48 birds. The control group (G1) was fed dry; while, group 2 (G2) received wet feed supplemented with 1.00 g water per g of feed and group 3 (G3) received wet feed supplemented with 1.20 g water per g of feed. Results revealed that G3 had significantly superior feed conversion ratios, lower feed intake, and increased body weight and weight gain compared to G2 and G1. Among the three treatment groups, there were no variations in blood plasma indicators. In comparison with G1, duodenum and ileum in G2 had higher villus height. The G3 revealed higher net profit margins and 18.89% saving of feed compared to G1, suggesting that it may be a valuable tool for lowering chicken feed costs.

Effects of lercanidipine on traumatic spinal cord injury: an experimental study.

Spinal cord injury is a devastating trauma that leaves survivors at risk for several medical complications throughout their lives. Lercanidipine, a third-generation calcium channel blocker, possesses anti-apoptotic, anti-inflammatory, and antioxidative properties. This study aimed to evaluate the neuroprotective effects of lercanidipine in an experimental spinal cord trauma model. Twenty-one Wistar rats were randomly assigned to three groups. Group 1 (G1) underwent laminectomy. Group 2 (G2) were subjected to trauma following laminectomy. Group 3 (G3) were exposed to trauma following laminectomy and treated with lercanidipine. Lercanidipine was administered intraperitoneally for seven days. Histopathological and immunohistochemical evaluations were conducted. Regarding Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining, there was no significant difference among the groups. However, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) levels were significantly different across the groups. G2 had significantly higher NF-κB levels compared to G1 and G3. Lercanidipine, a third-generation calcium channel blocker, is effective against inflammatory responses induced in spinal cord injury. Further studies are required to determine its capability in preventing apoptosis or improving functional recovery. To the best of our knowledge, this study is the first in the literature to examine the neuroprotective effects of lercanidipine on spinal cord injury.

Doubly charged dimers and trimers of heavy noble gases.

Many doubly charged heteronuclear dimers are metastable or even thermodynamically stable with respect to charge separation. Homonuclear dicationic dimers, however, are more difficult to form. He22+ was the first noble gas dimer predicted to be metastable and, decades later, observed. Ne22+ is the only other dicationic noble gas dimer that has been detected so far. Here, we present a novel approach to form fragile dicationic species, by post-ionization of singly charged ions that are embedded in helium nanodroplets (HNDs). Bare ions are then extracted by colliding the HNDs with helium gas. We detect homonuclear doubly charged dimers and trimers of krypton and xenon, but not argon. Our multi-reference ab initio calculations confirm the stability of Kr22+, Kr32+, Xe22+, Xe32+, and Ar22+, but put the stability of Ar32+ towards dissociation to Ar+ + Ar2+ into question.

Chondrules from the ordinary chondrite Itawa Bhopji (L3-5): Noble gases and nitrogen

Noble gases and nitrogen compositions are investigated in chondrules of Itawa Bhopji (L3-5) chondrite. Single chondrule and bunch of chondrules were analysed in this work. Isotopic ratios of noble gases in chondrules indicate mixture of Q-HL-SW and cosmogenic. The cosmic ray exposure age of the chondrules using 21Ne are 30.0 ± 2.3 and 25.9 ± 2.5 Ma. No excess cosmic ray exposure (CRE) age observed in the chondrules from that of bulk aliquot of dark lithology. The trapped nitrogen signature, δ15Nt in the chondrules, is +15.8 ± 2.2‰ (bunch of chondrules) and +15.1 ± 2.3‰ (single chondrule). Trapped nitrogen isotopic signature in chondrules differs from dark and light lithology of the meteorite and it is also distinct from metal separates. Trapped nitrogen composition in chondrules differs than Q-phase, solar wind (SW) and HL components. This implies that chondrules in Itawa Bhopji (L3-5) chondrite composed of isotopically distinct component than any of the known reservoir. Distinct trapped nitrogen isotopic signatures in the constituents of a meteorite indicates their formation at various places with the heliocentric distance. The abundance of nitrogen in chondrules is 6.14 ± 0.51 ppm (bunch) and 5.71 ± 0.48 ppm (single). Radiogenic 129Xe from the decay of 129I was observed in chondrules, indicative of their formation in early solar system.

Metal-organic cages for gas adsorption and separation.

The unique high surface area and tunable cavity size endow metal-organic cages (MOCs) with superior performance and broad application in gas adsorption and separation. Over the past three decades, for instance, numerous MOCs have been widely explored in adsorbing diverse types of gas including energy gases, greenhouse gases, toxic gases, noble gases, etc. To gain a better understanding of the structure-performance relationships, great endeavors have been devoted to ligand design, metal node regulation, active metal site construction, cavity size adjustment, and function-oriented ligand modification, thus opening up routes toward rationally designed MOCs with enhanced capabilities. Focusing on the unveiled structure-performance relationships of MOCs towards target gas molecules, this review consists of two parts, gas adsorption and gas separation, which are discussed separately. Each part discusses the cage assembly process, gas adsorption strategies, host-guest chemistry, and adsorption properties. Finally, we briefly overviewed the challenges and future directions in the rational development of MOC-based sorbents for application in challenging gas adsorption and separation, including the development of high adsorption capacity MOCs oriented by adsorbability and the development of highly selective adsorption MOCs oriented by separation performance.

Unveiling distinct bonding patterns in noble gas hydrides via interference energy analysis

Despite their apparent simplicity, the helium hydride ion (HeH+) and its analogues with heavier noble gas (Ng) atoms present intriguing challenges due to their unusual electronic structures and distinct ground-state...

Recent membrane separation technology for noble gas recovery

This review summarizes the membrane separation for the recovery of noble gases, which are significant in various disciplines due to their unique properties.

Structure, stability, reactivity and bonding in noble gas compounds.

Noble gases (Ngs) are recognized as the least reactive elements due to their fully filled valence electronic configuration. Their reluctance to engage in chemical bond formation necessitates extreme conditions such as low temperatures, high pressures, and reagents with high reactivity. In this Perspective, we discuss our endeavours in the theoretical prediction of viable Ng complexes, emphasizing the pursuit of synthesizing them under nearly ambient conditions. Our research encompasses various bonding categories of Ng complexes and our primary aim is to comprehend the bonding mechanisms within these complexes, utilizing state-of-the-art theoretical tools such as natural bond orbital, energy decomposition, and electron density analyses. These complex types manifest distinct bonding scenarios. In the non-insertion type, the donor-acceptor interaction strength hinges on the polarizing ability of the binding atom, drawing the electron density of the Ng towards itself. In certain instances, especially with heavier Ng elements, this interaction reaches a magnitude where it can be considered a covalent bond. Conversely, in most insertion cases, the Ng prefers to share electrons to form a covalent bond on one side while interacting electrostatically on the other side. In rare cases, both bonds may be portrayed as electron-shared covalent bonds. Furthermore, a host cage serves as an excellent platform to explore the limits of achieving Ng-Ng bonds (even for helium), under high pressure.

Exploring the energy landscape of graphynes for noble gas adsorption using swarm intelligence

Gas adsorption on one-atom-thick membranes is a growing technology for separation applications owing to its excellent energy efficiency. Herein, we investigate the adsorption of the noble gases, Ne, Ar and Kr on graphynes (GYs), a novel class of one-atom-thick carbon membranes using a swarm intelligence technique, namely particle swarm optimization (PSO). Modeling the adsorption of noble gas clusters on two-dimensional substrates requires a thorough examination of the energy landscape. The high dimensionality of the problem makes it tricky to employ ab initio methods for such studies, necessitating the use of a metaheuristic global optimization technique such as PSO. We explored the adsorption of 1–30 atoms of Ne, Ar and Kr on α-, β-, γ- and rhombic-GYs to predict the most suitable form of GY for the adsorption of each of the gases. Employing the dispersion-corrected density functional theory (DFT-D) data for the adsorption of single gas atoms as the reference data, we parametrized two empirical pairwise potentials, namely, Lennard-Jones (LJ) and improved Lennard-Jones (ILJ) potentials. We then analyzed the growth pattern as well as the energetics of adsorption using the parametrized potentials, in combination with the PSO technique, which enabled us to predict the best possible membrane for the adsorption of the noble gases: α-GY for Ne and γ-GY for Ar and Kr. The accuracy of our modeling approach is further validated against DFT-D computations thereby establishing that PSO, when combined with the ILJ potential, can serve as a computationally feasible approach for modeling gas adsorption on GYs.

Analyses of the energy efficiency enhancement in Bulgarian health care premises

The presented study examines how hospital buildings in Bulgaria consume energy, reduce emissions, and save energy. The study uses data from energy efficiency surveys of 38 hospital buildings, where 137 energy-saving measures were implemented between 2015 and 2021. These hospital buildings range in size from 465 m2 to 19,026 m2, with a total studied area of 151,306 m2, divided into three groups for analytical convenience. The study presents detailed findings on annual energy savings, with the highest savings achieved in Group 2 (G2), reaching an impressive 51.1% in 2021. Furthermore, the study analyzes the reduction in carbon emissions, with Group 2 again showing the largest decrease, reducing emissions by 2,097 tCO2 in 2019. These results underscore the significant positive impact of the implemented energy-saving measures, demonstrating substantial improvements in the energy efficiency of the studied hospital buildings. In addition, to highlight the financial and environmental benefits of the reduced energy consumption and lower carbon emissions, the study also offers a valuable model for similar initiatives in other regions. It emphasizes the critical importance of energy efficiency and how targeted measures can effectively contribute to sustainable development in the healthcare sector. This comprehensive analysis provides policymakers, healthcare administrators, and energy efficiency advocates with valuable insights and effective strategies for reducing energy use and emissions in hospital buildings. By showcasing the success of these measures, the study aims to inspire broader adoption of energy efficiency practices, ultimately contributing to global sustainability efforts.

Selenium nanoparticles effect on foot and mouth disease vaccine in local Awassi breed male lambs.

The goal of this research was to evaluate where selenium nanoparticles impact the activity of antibodies in immunized lambs with foot and mouth vaccines by modulating the immune system. Two groups of lambs of 3-4 months of age were injected with 1 ml of ARRIAH-VAC vaccine intramuscularly in the neck, five Lambs were given selenium nanoparticles (size 100 nm) oral administration of selenium nano dose of 0.1 mg/kg of body mass once every day for sixty days considered as group one (G1) while the other five used as control Group 2 (G2). This resulted in the establishment of an immune response, as evidenced by a rise in antibody titer in the blood using the ELISA test for three serotypes A, O, and Asia 1, when selenium nanoparticles were given orally at a dose of 0.1 mg/kg body weight after immunization, we noticed a significant (p >0:05) selenium nano group increase in IgG response in all immunized groups in contrast to lambs that had only received the foot-and-mouth disease vaccine. We have demonstrated that selenium nanoparticles administered orally significantly enhance immune responses while also increasing body weight.

Diversity of protonated mixed pyrene-water clusters investigated by collision induced dissociation.

Protonated mixed pyrene-water clusters, (Py)m(H2O)nH+, where m = [1-3] and n = [1-10], are generated using a cryogenic molecular cluster source. Subsequently, the mass-selected mixed clusters undergo controlled collisions with rare gases, and the resulting fragmentation mass spectra are meticulously analyzed to discern distinct fragmentation channels. Notably, protonated water cluster fragments emerge for n ≥ 3, whereas they are absent for n = 1 and 2. The experimental results are complemented by theoretical calculations of structures and energetics for (Py)(H2O)nH+ with n = [1-4]. These calculations reveal a shift in proton localization, transitioning from the pyrene molecule for n = 1 and 2 to water molecules for n ≥ 3. The results support a formation scenario wherein water molecules attach to protonated pyrene PyH+ seeds, and, by extension, to (Py)2H+ and (Py)3H+ seeds. Various isomers are identified, corresponding to potential protonation sites on the pyrene molecule. Protonated polycyclic aromatic hydrocarbons are likely to be formed in cold, dense interstellar clouds and protoplanetary disks due to the high proton affinity of these species. Our findings show that the presence of protonated PAHs in these environments could lead to the formation of water clusters and mixed carbon-water nanograins, having a potential impact on the water cycle in regions of planet formation.

Precision spectroscopic measurements of few-electron atomic systems in extreme ultraviolet region

<sec>Precision spectroscopic measurements on the few-electron atomic systems have attracted much attention because they shed light on important topics such as the “proton radius puzzle” and testing quantum electrodynamics (QED). However, many important transitions of few-electron atomic systems are located in the vacuum/extreme ultraviolet region. Lack of a suitable narrow linewidth light source is one of the main reasons that hinder the further improvement of the spectral resolution.</sec><sec>Recently, narrow linewidth extreme ultraviolet (XUV) light sources based on high harmonic processes in rare gases have opened up new opportunities for precision measurements of these transitions. The recently implemented XUV comb has a shortest wavelength of about 12 nm, a maximum power of milliwatts, and a linewidth of about 0.3 MHz, making it an ideal tool for precision measurements in the XUV band. At the same time, the Ramsey comb in the XUV band can achieve a spectral resolution of the kHz range, and may operate throughout the entire XUV band.</sec><sec>With these useful tools, direct frequency spectroscopy and Ramsey comb spectroscopy in the XUV region are developed, and precision spectroscopic measurements of few-electron atomic systems with these methods are becoming a hot topic in cutting-edge science. In this paper, we provide an overview of the current status and the progress of relevant researches, both experimentally and theoretically, and discuss the opportunities for relevant important transitions in the extreme ultraviolet band.</sec>

Comparison of helium and argon for the production of carbon monoxide (CO) by a plasma jet for biomedical applications

Carbon monoxide (CO) has anti-inflammatory properties and its production by plasma could be a significant advantage in the field of plasma medicine. We characterized a pulsed kHz-driven plasma jet to produce CO for biomedical applications. With no target interaction, the CO2 conversion into CO, the breakdown voltage and energy delivered to the plasma were investigated for two noble carrier gases: helium and argon. The breakdown voltage and the energy delivered to the plasma in argon gas were twice as high as in helium. The breakdown voltage was barely affected by the gas flow rate and the applied voltage, while it decreased slightly with the excitation frequency because the amount of residual charges increases with the frequency. However, the energy delivered to the plasma was not particularly affected by a change in frequency or gas flow rate, while it increased linearly with the applied voltage. CO production rose from a couple of ppm to about 2000 ppm for a specific energy input from 2 to 2000 J/L (5 × 10−4 to 5200 × 10−4 eV/(atom or molecule)), making this plasma source safe in terms of CO production for biomedical applications. Unlike literature results, the nature of the noble carrier gas did not have an impact on CO production. The CO concentration produced with 0.3% CO2 admixture increased linearly with the specific energy input (SEI) until reaching a plateau at about 2100ppm. This implies that loss processes were negligible and that CO2 dissociation was mainly due to energetic particles such as electrons and excited noble atoms. The conversion decreased with the ratio of CO2. Helium and argon as carrier gases are equivalent in terms of CO production and the CO concentration can be controlled by the SEI and the ratio of CO2.

Discharge characteristics and parameter diagnosis of brush-shaped air plasma plumes under auxiliary discharge

Atmospheric pressure plasma jet (APPJ) can produce plasma plumes rich in active species, which has a wide scope of applications. From the perspective of applications, it is one of the hot issues in APPJ research to generate a diffuse plasma plume on a large scale. At present, large-scale plasma plume has been produced by noble working gases, which is more economic and valuable if it is reproduced by air used as the working gas. In this work, an APPJ with an auxiliary discharge is proposed, with which a large-scale air plasma plume with a brush shape is produced. Results indicate that the brush-shaped air plume can exist by changing voltage amplitude (<i>V</i><sub>p</sub>) in a certain range. The length and brightness of the plasma plume increase with <i>V</i><sub>p</sub> increasing. The waveforms of voltage and light emission signalindicate that the discharge can start at most once within half a cycle of applied voltage. The probability of discharge and the intensity of light emission pulse for each half a voltage cycle increase with <i>V</i><sub>p</sub> increasing, but the voltage value at the discharge moment decreases with <i>V</i><sub>p</sub> increasing. High-speed imaging study shows that the generation mechanisms of diffuse brush-shaped air plasma plumes and small-scale air plasma are similar, both originating from the temporal superposition of bifurcated normal flow light. In addition, optical emission spectra from the brush-shaped air plasma plume are utilized to study electron temperature, electron density, molecular vibrational temperature, and gas temperature. With <i>V</i><sub>p</sub> increasing, gas temperature is low and almost unchanged, while electron density, electron temperature, and molecular vibrational temperature increase. In addition, OH concentration of the plasma plume is investigated by laser-induced fluorescence, indicating that OH is uniformly distributed, and its concentration increases with the <i>V</i><sub>p</sub> increasing. All these results mentioned above are qualitatively analyzed.

From weak to strong interactions between halogen and noble gas atoms in halonium complexes.

Halonium cations can interact through a halogen bond with individual noble gas atoms. These bonds can vary widely in strength from 1 to 25 kcal mol-1. Quantum chemical analyses consider X to be attached to a propyl group, pyridine N, or Xe atom, with X = Cl, Br, and I, interacting with Ar, Kr, and Xe atoms. The most weakly bound dyads are bound primarily by electrostatics, but charge transfer takes a larger role for the more tightly held complexes.

Noble gas hydrides: theoretical prediction of the first group of anionic species.

The first group of anionic noble-gas hydrides with the general formula HNgBeO- (Ng = Ar, Kr, Xe, Rn) is predicted through MP2, Coupled-Cluster, and Density Functional Theory computations employing correlation-consistent atomic basis sets. We derive that these species are stable with respect to the loss of H, H-, BeO, and BeO-, but unstable with respect to Ng + HBeO-. The energy barriers of the latter process are, however, high enough to suggest the conceivable existence of the heaviest HNgBeO- species as metastable in nature. Their stability arises from the interaction of the H- moiety with the positively-charged Ng atoms, particularly with the σ-hole ensuing from their ligation to BeO. This actually promotes relatively tight Ng-H bonds featuring a partially-covalent character, whose degree progressively increases when going from HArBeO- to HRnBeO-. The HNgBeO- compounds are also briefly compared with other noble-gas anions observed in the gas phase or isolated in crystal lattices.

Hydrogen bond types which do not fit accepted definitions.

There are various interactions that either partially fit or do not fit the currently accepted definitions of the hydrogen bond. However, they possess characteristics of this interaction. It seems that it is partly connected to the fact that these definitions are not precise. The typical 3c-4e (three centres - four electrons) A-H⋯B hydrogen bond is characterized by the single-atom A and B centres that are highly electronegative. On the other hand, non-typical interactions that do not fit the hydrogen bond definitions well are characterised by uncommon proton donors and/or proton acceptors. The cases of multi-centre proton acceptors, π-electron or σ-electron systems are well known - such interactions are designated as A-H⋯π and A-H⋯σ hydrogen bonds, respectively. However, the cases of interactions with the multi-centre proton donors and proton acceptors do not fit the majority of definitions of hydrogen bond. The π⋯H+⋯π system in the proton-bound homodimer of acetylene is an example. This system can be classified as a hydrogen bond according to the two-sites hydrogen bond, 2sHB, definition. There are various types of interactions discussed in this review; among them, those that are undoubtedly unclassified as hydrogen bonds, i.e., hydride bonds, and charge inverted hydrogen bonds, CIHBs. Special emphasis is also put here on the proton sponges and other systems such as the [FHF]- anion or [NgHNg]+ cation (Ng is the noble gas centre).