High Concentration Hydrogen Research Articles

Lung macrophages are involved in lung injury secondary to repetitive diving.

This study aimed to establish an animal model of decompression-induced lung injury (DILI) secondary to repetitive diving in mice and explore the role of macrophages in DILI and the protective effects of high-concentration hydrogen (HCH) on DILI. Mice were divided into three groups: control group, DILI group, and HCH group. Mice were exposed to hyperbaric air at 600 kPa for 60 min once daily for consecutive 3 d and then experienced decompression. In HCH group, mice were administered with HCH (66.7% hydrogen and 33.3% oxygen) for 60 min after each hyperbaric exposure. Pulmonary function tests were done 6 h after decompression; the blood was harvested for cell counting; the lung tissues were harvested for the detection of inflammatory cytokines, hematoxylin and eosin (HE) staining, and immunohistochemistry; western blotting and polymerase chain reaction (PCR) were done for the detection of markers for M1 and M2 macrophages. Our results showed that bubbles formed after decompression and repeated hyperbaric exposures significantly reduced the total lung volume and functional residual volume. Moreover, repetitive diving dramatically increased proinflammatory factors and increased the markers of both M1 and M2 macrophages. HCH inhalation improved lung function to a certain extent, and significantly reduced the pro-inflammatory factors. These effects were related to the reduction of M1 macrophages as well as the increase in M2 macrophages. This study indicates that repetitive diving damages lung function and activates lung macrophages, resulting in lung inflammation. HCH inhalation after each diving may be a promising strategy for the prevention of DILI.

Outstanding self-lubrication of SiC ceramic with porous surface/AlCoCrFeNiTi0.5 high-entropy alloy tribol-pair under 90 wt% H2O2 harsh environment

High-concentration hydrogen peroxide solution (HCHP) was regard as potential fuel resources. However, mechanical wear of moving parts under HCHP was energy-wasteful and dangerous. This work designed a novel SiC ceramic/AlCoCrFeNiTi0.5 high-entropy alloy tribo-pair, which successfully achieved outstanding self-lubrication under HCHP. The lubrication behavior of the proposed tribo-pair mainly benefitted from three aspects: (i) oxidation and hydrolysis reactions of SiC ceramic, (ii) hydrodynamic and secondary lubrication effects of surface pores, (iii) inhibited adhesion behaviors between SiC ceramic and AlCoCrFeNiTi0.5 alloy. Rounding the pore edges of SiC ceramic further improved the load-carrying capacity of self-lubrication. The wear bottleneck problem under harsh HCHP was solved in this work.

Regulating vesicle bilayer permeability and selectivity via stimuli-triggered polymersome-to-PICsome transition

Compared to liposomes, polymersomes of block copolymers (BCPs) possess enhanced stability, along with compromised bilayer permeability. Though polyion complex vesicles (PICsomes) from oppositely charged block polyelectrolytes possess semipermeable bilayers, they are unstable towards physiologically relevant ionic strength and temperature; moreover, permselectivity tuning of PICsomes has remained a challenge. Starting from a single component diblock or triblock precursor, we solve this dilemma by stimuli-triggered chemical reactions within pre-organized BCP vesicles, actuating in situ polymersome-to-PICsome transition and achieving molecular size-selective cargo release at tunable rates. UV light and reductive milieu were utilized to trigger carboxyl decaging and generate ion pairs within hydrophobic polymersome bilayers containing tertiary amines. Contrary to conventional PICsomes, in situ generated ones are highly stable towards extreme pH range (pH 2-12), ionic strength (~3 M NaCl), and elevated temperature (70 °C) due to multivalent ion-pair interactions at high local concentration and cooperative hydrogen bonding interactions of pre-organized carbamate linkages.

Catalyst layer, method for producing the same, membrane electrode assembly and electrochemical cell

In this research, selective catalytic oxidation was applied to remove high-concentration hydrogen sulfide in landfill gas. The removal efficiency of H2S was the best with V/TiO2 catalyst produced by wet impregnation among. The optimum vanadium content was 10 %. In addition, selective conversion to elemental sulfur and generation of SO2 could be controlled by adjusting O2/H2S ratio. The larger the cell per square inch that affected the performance of the honeycomb-type catalyst, the greater the removal efficiency of H2S according to increase in specific surface area. An analysis of long-term performance of the honeycomb-type catalyst with landfill gas including CH4 and CO2 revealed that more than 90 % of H2S was removed. In addition, the performance of the catalyst could be recovered by thermal regeneration. Considering that the performance of a catalyst can be recovered for durability and regeneration, V/TiO2 coated honeycomb-type catalyst can be used in the actual process.

Application and regeneration of honeycomb-type catalysts for the selective catalytic oxidation of H2S to sulfur from landfill gas

In this research, selective catalytic oxidation was applied to remove high-concentration hydrogen sulfide in landfill gas. The removal efficiency of H2S was the best with V/TiO2 catalyst produced by wet impregnation among. The optimum vanadium content was 10 %. In addition, selective conversion to elemental sulfur and generation of SO2 could be controlled by adjusting O2/H2S ratio. The larger the cell per square inch that affected the performance of the honeycomb-type catalyst, the greater the removal efficiency of H2S according to increase in specific surface area. An analysis of long-term performance of the honeycomb-type catalyst with landfill gas including CH4 and CO2 revealed that more than 90 % of H2S was removed. In addition, the performance of the catalyst could be recovered by thermal regeneration. Considering that the performance of a catalyst can be recovered for durability and regeneration, V/TiO2 coated honeycomb-type catalyst can be used in the actual process.

Hydrogen gas protects against delayed encephalopathy after acute carbon monoxide poisoning in a rat model

ABSTRACTObjective: The protective effects of 2%-4% hydrogen gas in delayed encephalopathy after acute carbon monoxide poisoning (DEACMP) have been previously reported. This study aimed to assess the neuroprotective effects of high concentration hydrogen (HCH) on DEACMP.Methods: A total of 36 male Sprague-Dawley rats were divided into 3 groups. In the DEACMP group, rats were exposed to CO to induce CO poisoning; in the HCH group, the animals were exposed to 67% H2 and 33% O2 at 3,000 mL/min for 90 min immediately after CO poisoning. Neurological function was evaluated at 1 and 9 days after poisoning. Then, the contents of malondialdehyde, 3-nitrotyrosine and 8-hydroxy-2-deoxyguanosine, as well as superoxide dismutase activity in the serum, cortex and hippocampus were detected by ELISA. Additionally, the mRNA and protein expression levels of Nrf2 and downstream genes were detected by RT-PCR and Western blotting, respectively.Results: Our results showed that CO poisoning significantly impaired neurological function which was improved over time, and HCH markedly attenuated neurological impairment following CO poisoning. In addition, CO poisoning resulted in increased levels of malondialdehyde, 3-nitrotyrosine and 8-hydroxy-2-deoxyguanosine and markedly reduced superoxide dismutase activity at 1 and 9 days, which were significantly inhibited by HCH at 9 days. Finally, CO poisoning increased the mRNA and protein levels of Nrf2 and downstream genes, and HCH further induced the anti-oxidative capability.Conclusion: These findings indicate the neuroprotective effects of HCH on DEACMP, which are related to the activation of Nrf2 signaling pathway.

Experimental investigation of the effect of nozzle throat diameter on the performance of a hybrid rocket motor with swirling injection of high-concentration hydrogen peroxide

One of the issues of using a normal graphite nozzle for the hybrid rocket propulsion is the serious throat erosion due to combustion with a higher O/F ratio. This may undermine the throttling capability of the hybrid rocket engine. In this study, we would like to address how the propulsion performance changes under the conditions of different nozzle throat diameters and O/F ratios. We designed and tested a 40-kgf class single-port hybrid rocket motor with the swirling injection of oxidizer, which utilizes the 90 wt% hydrogen peroxide and polypropylene (PP) as oxidizer and fuel, respectively. Three different diameters of graphite nozzle throat (10, 11, and 12 mm) were used to approximate various conditions of nozzle erosion, while the mass flow rates of the injected oxidizer were kept the same. The hot-fire test results indicated that the thrust was nearly the same even the nozzle throat diameters and O/F ratios were different. Especially, the discrepancies among the measured thrusts and oxidizer ISP under various test conditions were found to be less than 1%, which is highly beneficial for the purpose of the thrust control using mass flow rate control of the oxidizer for a hybrid rocket engine with swirling injection of high-concentration hydrogen peroxide.

In situ growth of hexagonal prism-like Ni(OH)2 microrods on nickel foam as binder-free electrodes

In this paper, we report in situ growth of hexagonal prism-like Ni(OH)2 microrods via one-step hydrothermal process, where nickel foam is directly oxidized in a high concentration hydrogen peroxide (H2O2) solution without additional nickel sources, surfactant, or post-treatment. The nickel foam not only serves as a nickel source but also as 3D scaffold for Ni(OH)2 growth to form binder-free electrodes. The in situ growth can ensure close contact between conductive Ni foam substrate and as-formed Ni(OH)2 microrods, providing efficient electron collection paths and electrochemical stability. Mass loading of Ni(OH)2 on nickel foam could be tailored by adjusting the concentration H2O2. Possible growth mechanism of hexagonal prism-like Ni(OH)2 microrods is discussed to understand the morphologies under various H2O2 concentrations. When works as a binder-free electrode, the Ni(OH)2-coated nickel foam exhibits a remarkable areal capacitance ~ 1.598 C cm−2 (560 C g−1) at a current density of 1 mA cm−2, relatively high rate capability with 57.14% areal capacitance retained at 10 mA cm−2, as well as better cycling stability with 72.9% areal capacitance remained after 3000 charge-discharge cycles. Such superior performance demonstrates that Ni(OH)2 microrods in situ grown on metallic nickel foam substrate might be a potential electrode material for electrochemical capacitors.

The Effect of Sealing Ring Gap on Hydrogen Peroxide Electric Pump

Chained decomposition will take place in terms of overheat of high concentration hydrogen peroxide, which will further cause explosion, in the electric pump pressurized liquid propellant rocket engine, which takes hydrogen peroxide of high concentration as oxidizing agent, the design of oxidant pump should consider safety factor for temperature rising of hydrogen peroxide and the influence of pump efficiency on quality control of motor system simultaneously. It’s very important to know the effect of sealing ring gap at the bottom of impeller on temperature rising of bearing chamber and pump efficiency. So, this paper firstly establishes mathematical modal about the effect of sealing ring gap on temperature rising of bearing chamber and pump efficiency loss, to gain influencing curve, and then it analyzes parameters of cooling flow and mechanism of temperature rising, and give reasonable gap values, which take both safety and efficiency into account. Finally, 3D simulation calculation is carried out through pumplinx to verify the accuracy of this influence model.

High response and low concentration hydrogen gas sensing properties using hollow ZnO particles transformed from polystyrene@ZnO core-shell structures

High quality, closely packed nanorods (NRs) textured ZnO hollow particles were prepared via thermal treatment of polystyrene@ZnO core-shell structures at 300 °C. Polystyrene@ZnO core-shell structures were synthesized using a chemical route. These hollow ZnO particles were investigated for hydrogen gas sensing properties. Morphological properties were studied using field emission scanning electron microscope (FE-SEM). Structural parameters and molecular fingerprint confirmation were carried out by x-ray diffraction (XRD) and Raman analysis respectively. The elemental compositions and atomic species of sensor materials were studied using energy dispersive spectrometer (EDS) analysis and x-ray photoelectron spectroscopy (XPS) spectra respectively. The study of atomic planar arrangements and crystalline nature were examined by using a high-resolution transmission electron microscope (HR-TEM) micrograph and selected area electron diffraction (SAED) pattern respectively. Hollow ZnO particles sensor was revealed remarkable selectivity towards hydrogen (H2) gas. The lowest H2 detection limit of ZnO sensor was at 2 ppm with the response of 7%, whereas 89% gas response was recorded for 100 ppm at optimized temperature 225 °C with response time 139 s. Gas response as a function of operating temperatures as well as gas concentrations was tested along with good sensor stability. The transient gas response and selectivity studies were carried out and analyzed. ZnO growth and gas sensing mechanisms were elucidated.

Intensification of esterification process in TBP synthesis by in situ vapor stripping

AbstractBACKGROUNDOver the past few decades, tri‐n‐butyl phosphate (TBP) has been a widely used and irreplaceable extractant that can extract a variety of heavy metal ions and inorganic acids. The conventional process of tri‐n‐butyl phosphate synthesis has the problem of low yield. The in situ vapor stripping method was developed to intensify the tri‐n‐butyl phosphate synthesis reaction.RESULTSIn this work, the coupling process of in situ vapor stripping and reaction was proposed for the first time in the process of synthesis of TBP. It was found that the reaction of high concentration hydrogen chloride and 1‐butanol would produce water, which resulted in increasing the possibility of side reactions, especially when the temperature was higher than 55 °C. In the lower temperature range, n‐pentane was selected as the stripping medium, which effectively removed hydrogen chloride from the reaction system by in situ vapor stripping. The FT‐IR analysis confirmed that TBP can be synthesized successfully by the vapor stripping process. In addition, the effects of n‐pentane volume, temperature and stripping time on the yield of TBP and the amount of hydrogen chloride stripped were investigated. By applying the optimum reaction conditions, the yield of TBP was increased to 94%, larger than that of the current industrial process whose yield is only 80%.CONCLUSIONThe in situ vapor stripping process is demonstrated to be an effective method for intensification of the esterification process in TBP synthesis. It can be used for other reactions which generate volatile gases as the byproduct. © 2018 Society of Chemical Industry

Hydrogen inhibits microglial activation and regulates microglial phenotype in a mouse middle cerebral artery occlusion model.

Microglia participate in bi-directional control of brain repair after stroke. Previous studies have demonstrated that hydrogen protects brain after ischemia/reperfusion (I/R) by inhibiting inflammation, but the specific mechanism of anti-inflammatory effect of hydrogen is poorly understood. The goal of our study is to investigate whether inhalation of high concentration hydrogen (HCH) is able to attenuate I/R-induced microglia activation. Eighty C57B/L male mice were divided into four groups: sham, I/R, I/R + HCH and I/R + N2/O2 groups. Assessment of animals happened in “blind” matter. I/R was induced by occlusion of middle cerebral artery for one hour). After one hour, filament was withdrawn, which induced reperfusion. Hydrogen treated I/R animals inhaled mix of 66.7% H2 balanced with O2 for 90 minutes, starting immediately after initiation of reperfusion. Control animals (N2/O2) inhaled mix in which hydrogen was replaced with N2 for the same time (90 minutes). The brain injury, such as brain infarction and development of brain edema, as well as neurobehavioral deficits were determined 23 hours after reperfusion. Effect of HCH on microglia activation in the ischemic penumbra was investigated by immunostaining also 23 hours after reperfusion. mRNA expression of inflammation related genes was detected by PCR. Our results showed that HCH attenuated brain injury and consequently reduced neurological dysfunction after I/R. Furthermore, we demonstrated that HCH directed microglia polarization towards anti-inflammatory M2 polarization. This study indicates hydrogen may exert neuroprotective effects by inhibiting the microglial activation and regulating microglial polarization. This study was conducted in agreement with the Animal Care and Use Committee (IACUC) and Institutional Animal Care guidelines regulation (Shanghai Jiao Tong University, China (approval No. A2015-011) in November 2015.

Inhalation of high-concentration hydrogen gas attenuates cognitive deficits in a rat model of asphyxia induced-cardiac arrest.

Cognitive deficits are a devastating neurological outcome seen in survivors of cardiac arrest. We previously reported water electrolysis derived 67% hydrogen gas inhalation has some beneficial effects on short-term outcomes in a rat model of global brain hypoxia-ischemia induced by asphyxia cardiac arrest. In the present study, we further investigated its protective effects in long-term spatial learning memory function using the same animal model. Water electrolysis derived 67% hydrogen gas was either administered 1 hour prior to cardiac arrest for 1 hour and at 1-hour post-resuscitation for 1 hour (pre- & post-treatment) or at 1-hour post-resuscitation for 2 hours (post-treatment). T-maze and Morris water maze were used for hippocampal memory function evaluation at 7 and 14 days post-resuscitation, respectively. Neuronal degeneration within hippocampal Cornu Ammonis 1 (CA1) regions was examined by Fluoro-Jade staining ex vivo. Hippocampal deficits were detected at 7 and 18 days post-resuscitation, with increased neuronal degeneration within hippocampal CA1 regions. Both hydrogen gas treatment regimens significantly improved spatial learning function and attenuated neuronal degeneration within hippocampal CA1 regions at 18 days post-resuscitation. Our findings suggest that water electrolysis derived 67% hydrogen gas may be an effective therapeutic approach for improving cognitive outcomes associated with global brain hypoxia-ischemia following cardiac arrest. The study was approved by the Animal Health and Safety Committees of Loma Linda University, USA (approval number: IACUC #8170006) on March 2, 2017.

Corrosive and tribological behaviors of AlCoCrFeNi-M high entropy alloys under 90 wt. % H2O2 solution

Abstract High concentration hydrogen peroxide solutions (HCHP) have been attractive as potentially future fuels. However, preparing inner moving-parts with both good compatibility and tribological properties under HCHP remains to be a challenge. Here, the high entropy alloys (HEAs)/Si3N4 tribol-pair with compatible alloy and self-lubricating counterpart was researched. The wear-mechanisms and alloy-structure effects were studied. As a result, the realization of lubricated friction depends on whether the condition meet Vformtion (formation velocity of colloidal films)-Vattrition (attrition velocity of colloidal films)>Vpit (increase velocity of pit depth and amount). HEAs with poorer corrosion resistance and higher strength could more easily achieve effective lubrication. The component inhomogeneity of different structures could promote the corrosion behavior.

PO-133 Effects of different concentrations of hydrogen on oxidative stress in rats with high intensity exercise

Objective Exercise-induced oxidative stress is due to the massive increase in free radicals caused by strenuous exercise, which exceeds the ability of self-clearing. It is one of the main causes of sports injury and sports fatigue. Eliminating excessive production of free radicals is the key to alleviating exercise induced oxidative damage. Therefore, the purpose of this study is to study the effect of hydrogen on exercise-induced oxidative damage, to explore its possible mechanism and to explore the best dose of hydrogen with different concentrations.
 Methods 40 male SD rats (200±20g) were randomly divided into five groups(n=8):sedentary, exercise control, low concentration hydrogen with exercise(H1), medium concentration hydrogen with exercise(H2), high concentration hydrogen with exercise(H3). The rats performed high-intensity exercise for 4 weeks, except the sedentary. rats that with Low, medium and high concentration hydrogen were placed in a hydrogen atmosphere with a concentration of 0.5%, 1% and 1.5% for 1 h immediately after each exercise (keeping the concentration of oxygen and nitrogen in the environment the same as those in the air). The rats were weighed weekly during the experiment. The next day after 4 weeks of training, the samples were collected, and the contents of total superoxide dismutase (T-SOD), catalase (CAT), total antioxidant capacity (T- AOC) and malondialdehyde (MDA) were determined respectively.
 Results The weight of exercise control was significantly lower than sedentary in the third and fourth weeks of exercise (P<0.05). Compared to sedentary rats, there was no significant difference in the weight of rats between H1, H2 and H3 group. The contents of T-AOC, CAT and T-SOD in exercise control were significantly higher than those in sedentary (P<0.05). The content of CAT in H2 group was significantly decreased compared with exercise control (P<0.01). Compared with exercise control, the T-AOC and T-SOD in the H2 group showed a downward trend but no statistical difference (P>0.05), there was no significant difference between the above indexes, compared with sedentary. In addition, there was no difference in T-SOD and CAT content between H1 group and exercise control; Compared with exercise control, there was no significant difference in T-SOD, T-AOC and CAT in H3 group. At the MDA level, each exercise group increased significantly compared with the sedentary (P<0.05), and the MDA levels in the H1, H2, and H3 groups were decreased compared with the exercise control, but there was no statistical difference.
 Conclusions It can be seen from the above results that different concentrations of hydrogen intervention can improve the weight loss of rats after intensive exercise. More importantly, the dosage and effect of 1% concentration of hydrogen is easier to remove the excessive radicals produced by intense exercise in the body, avoid the aggravation of oxidative stress, and have very good therapeutic effect. It provides a theoretical basis for the further study of the application of hydrogen in exercise oxidative damage.

Bubble-loop complexes induced by helium irradiation and effect of pre-irradiation and post-irradiation of hydrogen in reduced-activation ferritic/martensitic steel

ABSTRACTIn the present work, the synergistic effect of high concentration hydrogen and helium on the dislocation loops and bubbles as well as their correlations in reduced-activation ferritic/martensitic (RAFM) steels is investigated. Such an effect was transmuted from 14 MeV neutron irradiation and has been one of the most challenging issues for RAFM steels for future fusion reactors. After low dose (0.18 dpa) high concentration (5000 appm) single-ion helium irradiation at 723 K, very large dislocation loops were observed, and the majority of bubbles were inside dislocation loops, forming bubble-loop complexes. These bubble-loop complexes defects were also present in hydrogen/helium and helium/hydrogen sequential-ion irradiated steels. Pre-irradiated hydrogen ion effectively inhibited the later growth of loops induced by helium post-irradiation, and the higher the ratio of hydrogen to helium fluence, the greater the effect of inhibition. At high fluence of hydrogen pre-irradiation, the structure of bubble-loop complexes disappeared. On the other hand, hydrogen post-irradiation promoted the growth of loops induced by helium pre-irradiation, and the higher the ratio of hydrogen to helium fluence, the greater the effect of promotion. The mechanisms for hydrogen/helium synergistic effects are discussed.

Detached Eddy Simulation of hydrogen turbulent dispersion in nuclear containment compartment using GASFLOW-MPI

During the severe accident in nuclear power plants (NPPs), hydrogen is generated due to the zirconium-water reaction and released from the breaks in coolant pipe forming a locally high concentration hydrogen cloud in the steam generator (SG) compartment, which plays a key role for hydrogen safety analysis in NPPs. Accurate prediction of the turbulent dispersion process of hydrogen-steam gas mixture is a critical topic for a successful simulation of the flammable cloud distribution in SG compartment. In this study, the high-fidelity temporal evolution of the hydrogen turbulent dispersion in a SG compartment is performed using the Detached Eddy Simulation (DES) based on the parallel CFD code GASFLOW-MPI to capture more detailed unsteady turbulent information. Firstly, the newly developed DES turbulence model is validated using two turbulent benchmarks, a backward-facing step turbulent flow and a hydrogen turbulent jet. The simulation results are consistent well with the experimental data. Then a SG compartment model including one steam generator, two coolant pumps, a hot leg and two cold legs is built using the specialized auto-mesh generation module. There are two modes of turbulent dispersion behavior due to the turbulent driven force in the containment, i.e. jet dominated by initial monument and plume dominated by buoyancy. The simulation result shows that the decay rate for centerline velocity obeys 1/z law as well as hydrogen volume fraction, indicating a turbulent jet during the steam dominated phase. There is also a relatively long potential core region which could impinge on the bottom concrete floor for the downwards jet. While the hydrogen release transfers from a turbulent jet to a turbulent plume outside the region near the inlet during the hydrogen dominated phase. Different from the turbulent jet, the centerline velocity at the plume region decays with the slope 1/z1/3, and the decay rate for the centerline hydrogen volume fraction is 1/z5/3 during this phase. Compared with the jet flow, the potential core region of the plume flow is relatively short, forming a hydrogen cloud near the inlet. The combustibility evaluation shows that the combustion clouds can be generated in the source compartment at the hydrogen dominated phase. However, they will be diluted by the following persistent steam injection from the break. This can provide technical support for the design of hydrogen mitigation system.

Hydrothermal synthesis of p-type nanocrystalline NiO nanoplates for high response and low concentration hydrogen gas sensor application

High quality nanocrystalline NiO nanoplates were synthesized using surfactant and template free hydrothermal route. The gas sensing properties of NiO nanoplates were investigated. The nanoplates morphology of NiO with average thickness ~ 20 nm and diameter ~ 100 nm has been confirmed by FE-SEM and TEM. Crystalline quality of NiO has been studied using HRTEM and SAED techniques. Structural properties and elemental compositions have been analyzed by XRD and energy dispersive spectrometer (EDS) respectively. The detailed investigation of structural parameters has been carried out. The optical properties of NiO were analyzed from UV–Visible and photoluminescence spectra. NiO nanoplates have good selectivity towards hydrogen (H2) gas. The lowest H2 response of 3% was observed at 2 ppm, whereas 90% response was noted for 100 ppm at optimized temperature of 200 °C with response time 180 s. The H2 responses as functions of different operating temperature as well as gas concentrations have been studied along with sensor stability. The hydrogen sensing mechanism was also elucidated.

A-101, a Proprietary Topical Formulation of High-Concentration Hydrogen Peroxide Solution: A Randomized, Double-Blind, Vehicle-Controlled, Parallel Group Study of the Dose-Response Profile in Subjects With Seborrheic Keratosis of the Face.

Seborrheic keratosis (SK) is a common benign skin tumor, yet no topical treatments are approved in the United States. To evaluate the proprietary, stabilized, high-concentration hydrogen peroxide-based topical solution A-101 (32.5% and 40% concentrations) for treatment of facial SK lesions. In this multicenter, double-blind, vehicle-controlled study, eligible subjects were randomly assigned to receive up to 2 treatments of A-101 40%, A-101 32.5%, or vehicle solution applied to a single facial SK lesion. The primary efficacy assessment was the Physician's Lesion Assessment (PLA), a validated 4-ordinal scale. The primary end point, the mean reduction in PLA grade from baseline to Day 106 was 1.7 for A-101 40%, 1.4 for A-101 32.5%, and 0.1 for vehicle (p < .001, both concentrations vs vehicle). Lesions for 68%, 62%, and 5% of subjects, respectively, were judged to be clear or near clear (p < .001, both concentrations vs vehicle). Local skin reactions were predominantly mild and transient. No subjects discontinued because of treatment-related adverse events. A-101 solution demonstrated efficacy in treating SKs on the face. Greater magnitude of effect was seen with the 40% concentration than the 32.5% concentration. A-101 solution had a favorable safety and tolerability profile at both concentrations.

Hydrogen inhalation improves mouse neurological outcomes after cerebral ischemia/reperfusion independent of anti-necroptosis.

This study aimed to investigate the role of necroptosis in the neuroprotection of hydrogen in a mouse model of cerebral ischemia/reperfusion (I/R) injury. C57BL mice were randomly divided into sham group, I/R group, hydrogen/oxygen group (HO), nitrogen/oxygen group (NO). Middle cerebral artery occlusion (MCAO) for 1 hour followed by reperfusion was introduced to animals which were allowed to inhale 66.7% hydrogen/33.3% oxygen for 90 minutes since the beginning of reperfusion. Mice in NO group inhaled 66.7% nitrogen/33.3% oxygen. 24 hours after MCAO, brain infarction, brain water content and neurological function were evaluated. The protein expression of mixed lineage kinase domain like protein (MLKL) was detected at 3, 6, 12, 24 and 72 hours after reperfusion in HO group and the protein and mRNA expression of MLKL at 24 hours after MCAO in four groups. Hydrogen inhalation significantly reduced infarct volume, attenuated brain edema and improved neurobehavioral deficit in MCAO mice. The MLKL expression increased after MCAO and peaked at 6–24 hours after reperfusion. However, hydrogen inhalation had no significant effect on the MLKL expression at transcriptional and translational levels after MCAO. This study indicates high concentration hydrogen improves mouse neurological outcome after cerebral I/R injury independent of anti-necroptosis.