Constant Oxygen Research Articles

Resource recovery from wastewater by directing microbial metabolism toward production of value-added biochemicals.

Dynamic oxygen fluctuations in activated sludge were investigated to enhance valuable biochemical production during wastewater treatment. Batch experiments compared constant aeration with rapid cycling between oxygen-rich and oxygen-poor states. Fluctuating oxygen concentrations (0-2 mg/L) significantly increased production of valuable biochemicals compared to constant oxygen concentration (2 mg/L). Continuous oxygen perturbations increased free amino acids by 35.7 ± 7.6 % and free fatty acids by 76.4 ± 13.0 %, while intermittent perturbations with anoxic periods enhanced free amino acids by 42.4 ± 8.1 % and free fatty acids by 39.3 ± 7.7 %. Fourteen standard amino acids showed significant increases, and most fatty acids had carbon chain lengths between C12-C22. Mechanistically, oxygen perturbations activated FNR and ArcA regulons, resulting in lower relative abundances of TCA cycle enzymes and higher abundances of amino acid and fatty acid biosynthetic enzymes. These findings demonstrate that controlled oxygen fluctuations in wastewater treatment can enhance the biochemical value of activated sludge with minimal process modifications, facilitating resource recovery.

Hemodynamic Management with Vasopressin for Cardiovascular Surgery.

Background and Objectives: Vasopressin increases blood pressure through aquaporin-2-mediated water retention and is useful for managing hemodynamics after surgery. However, even after decades of study, clear clinical guidelines on doses and ideal use cases after cardiovascular surgery remain unclear. Here, the existing literature is synthesized on vasopressin use for cardiac surgeries and coupled with real-world clinical experience to outline a clearer clinical path for vasopressin use. Materials and Methods: Literature from 1966 to the present was searched, and information on surgical outcomes for cardiovascular surgery was extracted. Clinicians from the University of Tsukuba with extensive vasopressin experience in pediatric cardiovascular patients were consulted for general use guidelines. Results: Vasopressin response after cardiovascular surgery is multifaceted, and low-power trials, plus conflicting study reports, generally render it as a secondary choice behind norepinephrine. Clinical experience indicates that low doses of 0.2-0.3 mU/kg/min with constant blood pressure and oxygen monitoring for response are required. Although sole use is not recommended, vasopressin may aid in controlling hemodynamics when given with other volemic or osmolal drugs. Conclusions: Vasopressin may work in a select population of first-line non-responders, but relevant response factors remain unanalyzed and clear guidelines for use remain unestablished. Future, large-scale studies are needed to delineate temporal and demographic characteristics that affect response to vasopressin for the purpose of managing post-surgical capillary leakage and hemodynamics.

Hyaluronan-modified nanoceria for dry eye disease treatment.

Dry eye disease (DED), a prevalent ocular disorder, affects nearly half the global population, bringing enormous health and economic burden. Currently, the predominant treatments for DED involve the administration of artificial tears, which is often hindered by continuous administration and constant reactive oxygen species (ROS) stimulus. Therefore, hyaluronan (HA)-modified cerium oxide (CeO2) nanoparticles, HA-CeO2, were developed to achieve simultaneous ROS scavenging and enhanced tear film stability. HA-CeO2 was demonstrated to effectively scavenge ROS while concurrently downregulating the expression of inflammatory factors, such as MMP9 and IL-1β. Moreover, the anti-oxidative and anti-inflammatory effects of HA-CeO2 were further confirmed through a DED mouse model. In addition, the biocompatibility and safety of HA-CeO2 make it a promising treatment option for DED associated with inflammation and oxidative stress, offering novel insights into utilizing nanozymes in treating inflammation-oxidative stress-related diseases.

Cathode Reaction Studies in Lithium-Oxygen Battery through Operando XRD Measurements

Introduction The lithium-Oxygen (Li-O2; LOB) battery has obtained significant attention as a promising candidate for next-generation storage batteries due to its higher specific energy density compared to conventional lithium-ion batteries [1]. However, the mechanism of the cathode reaction remains unclear, and the type of Li2O2 produced during cathode discharge is still uncertain, mainly because it's challenging to directly observe the compounds generated at the cathode during LOB operations. By newly designing observation cells and improving laboratory XRD system, we clarified the discharge products and investigated the discharging process using operando XRD measurements and Rietveld refinements[2]. In this study, the cathode reaction mechanism was discussed based on the results of the operando XRD measurements. Experimental A newly designed electrochemical cell, covered with a Kapton film dome to enable constant oxygen flow to the cathode side of the LOB, was set to the diffractomator of the Rigaku Ultima IV XRD measurement system. In the XRD system, Cu Kα was utilized as the incident X-ray, and high-speed one-dimensional detector served as the detector. In the electrochemical cell, Ketjen black self-standing films were employed as cathode materials, and tetraglyme solution containing 0.5 M LiTFSI + 0.5 M LiNO3 + 0.2 M LiBr was used as the electrolyte solution. The LOB was discharged and charged at a constant current density of 0.4 mA/cm2 for 10 hours each (4.0 mAh/cm2), in which XRD profiles were recorded every 20 minutes. Rigaku's SmartLab Studio II software was utilized for Rietveld analysis of each XRD profile to determine the detailed cathode product and its crystal structure. Results and discussion Upon conducting operando XRD measurements and Rietveld analyses, the cathode reactions of the Li-O2 battery were investigated. The discharging and charging reactions at the cathode of the Li-O2 battery, as well as the x values of the major product Li2-xO2 during discharging, have been investigated and determined. In the XRD profile measured during discharging, several peaks attributed to the cathode product were observed. Detailed Rietveld analysis of these peaks revealed that LiO2 with the same P63/mmc space group structure as Li2O2 was immediately formed after discharge initiation, followed by the deposition of Li2-xO2 accompanied by an increase in lithium occupancy. As discharging progressed, the lattice constant gradually extended towards the c-axis direction, leading to the formation of Li1.5O2 at a discharge capacity of 4.0 mAh/cm2. In this presentation, we will discuss the discharge and charge reactions of the Li-O2 battery cathode in detail, and we will also discuss the charge-discharge cycle characteristics.

Cathode Reaction Analysis of Lithium-Oxygen Battery Based on Operando XRD Measurements

Introduction The lithium-air battery (LAB), which has ten times the energy density of conventional lithium-ion batteries (LIB), is one of the promising candidates for the next-generation storage batteries, and there are great expectations for its development [1]. However, the reaction mechanism of the cathode reaction is still unclear, and the type of Li2O2 that is the product of the cathode in discharging is still unknown. The main reason for this is considered to be that it was difficult to directly observe the compounds generated at the cathode during LAB operation. By improving the laboratory XRD and the observation cell, we succeeded in operando XRD measurements of the cathode reaction in the LAB. In addition, under general conditions, the cathode product was Li1.5O2 with some Li missing from the crystal lattice of Li2O2 [2]. Here, we describe the details and discuss the reaction mechanism. Experimental An electrochemical cell covered with a Kapton® dome was constructed to allow constant oxygen flow to the cathode side of the LAB, and was attached to the diffractomator of a Rigaku Ultima IV XRD measurement system. A Cu Ka was used as the incident x-ray, a high-speed one-dimensional detector was used as the detector, a Ketjen black free-standing film was used as the cathode material, and tetraglyme solution with 0.5 M LiTFSI + 0.5 M LiNO3 + 0.2 M LiBr was used as the electrolyte solution. The LAB was discharged and charged at a constant current density of 0.4 mA/cm2 for 10 hours (4.0 mAh/cm2) each, and the XRD profile was recorded every 20 minutes. Each XRD profile was subjected to Rietveld analysis using Rigaku’s SmartLab Studio II software to determine the cathode product and its crystal structure. Results and discussion In the XRD profile measured during discharging, a lot of peaks due to the cell parts were observed. But, several peaks due to the cathode product were also observed. As a result of detailed Rietveld analysis of these peaks, the cathode product at the discharging capacity of 4.0 mAh/cm2 was not Li2O2 but Li1.5O2. Instead of the normal LiO2 with a rectangular crystal structure, LiO2 with a hexagonal crystal structure, which is the same as that of Li2O2, was observed immediately after the discharge. As the discharge progressed, Li was added to it, and the lattice constant gradually extended in the c-axis direction, forming Li1.5O2 at a discharge of 4.0 mAh/cm2. In the presentation, the charging process and the charge-discharge cycle characteristics would also be discussed.

Experimental Study on the Influence of Staged Oxygen Consumption on the Oxidation Characteristics of Coal Spontaneous Combustion

The oxidation characteristic parameters of residual coal in working face change with the advance of coal seam. To explore the influence of dynamic oxygen-consuming environments, we examined the influence of reducing the oxygen concentration on the formation characteristics and characteristic parameters of coal oxidation products, conducted with temperature-programmed experiments under staged oxygen consumption. The correlation between the characteristic oxidation parameters was determined, and the critical oxygen concentration that determined the gas yield was obtained. The results show that after staged oxygen-consumption, the oxidation of coal is stronger than that under constant low oxygen, the oxidation products are greatly affected, and the influence of pyrolysis gas is small. The oxidation characteristic parameters such as gas product volume fraction, production rate, and heat release intensity are positively correlated with the oxygen-consumed temperature. We found that the oxidation reaction heat of coal is 180~330 kJ·mol−1, and the maximum and minimum exothermic intensities are significantly linearly correlated with the oxygen consumption rate. Finally, the critical oxygen concentrations for gas production rate under oxygen-consumed conditions were 17, 9, and 5%. These results have practical significance for strengthening the prevention and control of spontaneous combustion disasters in goafs.

Research on Ozone-Enhanced Oxidation of Industrial Zinc Sulfite from Flue Gas Desulfurization

ABSTRACT This study investigates the air oxidation and ozone-enhanced oxidation of zinc sulfite. Zinc sulfite was prepared by reacting pure or industrial zinc oxide with SO2 in water. The oxidation experiments were conducted under constant temperature conditions, with slurry, oxygen, and ozone concentrations in the ranges of 0.5–4%, 10–60%, and 1100–1920 ppm, respectively. The experiments involved determining the zinc ion concentration, sulfite concentration, dissolved oxygen, ozone concentration in the exhaust gas, and total organic carbon value for analysis of the oxidation process. The findings revealed that the mass transfer rate of O2 and/or O3 determined the reaction rate in the main stage of the oxidation process, while ozone affected the non-mass transfer control stage, resulting in an average enhancement of 15% in the oxidation rate. Furthermore, ozone causes organic matter attached to industrial zinc sulfite particles to fall off into the solution, significantly improving the oxidation ratio of industrial zinc sulfite.

Implicaciones de la alimentación continua sobre la demanda de oxígeno en un pez agástrico con intestino corto (Teleostei: Atherinopsidae)

Continuous illumination and increased feeding periods have enhanced growth in commercial fish species. However, oxygen consumption under these conditions has yet to be previously assessed in agastric short-intestine fish. This study evaluated Chirostoma estor (Atherinopsidae) oxygen consumption under three specific feeding and light regimes: resting-unfed, routine-fed, and continuous light/feeding. Fish in the continuous light/feeding condition presented oxygen consumption levels 60 and 20% higher than resting-unfed and routine-fed fish, respectively. The latter implies that constant high oxygen supply levels are required to satisfy the demand for C. estor raised under these high growth rate conditions. The present study shows the relevance of determining oxygen consumption levels during continuous illumination and extended feeding periods to consider optimal oxygen levels required to achieve better performance indicators, such as the growth and welfare of atherinopsids and species with similar digestive configurations.

Optimum Condition for the Formation of β-ionone by Thermal Decomposition of Carotenoids Extract from Orange Sweet Potato (Ipomoea Batatas L.)

Introduction The need for rose aromatic compounds is very high globally, where the beta-ionone compound as a precursor for rose aroma can be produced through the oxidation process of carotenoids, especially beta carotene. Therefore, Beta-ionone is the compound responsible for the rose fragrance, which is needed industrially. Carotenoids are easily degraded by various factors, namely heat, oxygen, light and enzymatic. This research has carried out heat degradation of carotene compounds extracted from orange sweet potato to determine the effect of heating time on forming aromatic compounds such as Beta-ionone and dihydroactinidiolide (dhA). Methodology Thermal degradation of carotene was carried out at 140°C for 1, 2, 3, and 4 h. The constant oxygen concentration of 7 l.h-1 was used to induce the oxidation. The spectrophotometric analysis of total carotene and the gas chromatographic-mass spectrometry analysis of volatile compounds were conducted to clarify the efficiency of the carotene degradation process and aromatic compounds' formation, respectively. Results Orange sweet potatoes contain 1.2% of carotenoids on a dry weight basis. Beta-ionone and dihydroactinidiolide compounds increased along with decreased total carotene value during heating. The results showed that heating sweet potato carotene at 140°C for 4 h caused carotene degradation of up to 93%. Therefore, the optimum thermal degradation treatment for the formation of β-ionone and dhA compounds was the heating condition at a temperature of 140°C for 4 h. Conclusion This research has shown the potential of sweet potatoes as a non-aromatic raw material that can be used to produce aromatic compounds. The use of the crude extract in this research means that the beta-ionone content in the product after oxidation is still low due to the presence of other components; this needs to be a concern for further research.

Pneumocystis jirovecii Pneumonia in a Liver Transplant Recipient With an Adverse Reaction to Trimethoprim/Sulfamethoxazole Treated With a Sulfonamide Desensitization Protocol: Case Report

Pneumocystis jirovecii pneumonia (PJP) is an opportunistic fungal infection that, in immunocompromised patients, can progress to respiratory failure and death. Since trimethoprim/sulfamethoxazole (TMP/SMX) chemoprophylaxis has become a standard management, the prognosis has improved. However, there are patients with a history of TMP/SMX intolerance who cannot receive chemoprophylaxis. We report on a 53-year-old male liver recipient treated with a standard triple immunosuppressive regimen in whom TMP/SMX was waived because of a history of allergy manifested as a generalized rash with edema more than 30 years ago. At transplantation, the immunologic risk was assessed as low, and liver graft function was normal. In the third month after engraftment, he developed dyspnea at rest required constant passive oxygen therapy. Ceftriaxone, azithromycin, and clindamycin were implemented. Mycophenolate acid was stopped, and tacrolimus was reduced. High-resolution computed tomography revealed interstitial pneumonia. Pneumocystis jirovecii pneumoniae was diagnosed from bronchoalveolar lavage. Instead of TMP/SMX, pentamidine and caspofungin were also used for PJP, with no improvement. After 3 weeks, the patient deteriorated. Because of his life-threatening condition, TMP/SMX was introduced in the sulfonamide desensitization protocol, including hydrocortisone and clemastinum. Within 4 days, the patient stabilized with no signs of TMP/SMX intolerance. Pneumonia subsided within a month, and TMP/SMX was prescribed lifelong. Prophylaxis for PJP with TMP/SMX still remains an important issue in transplant recipients. Adverse reaction to TMP/SMX in the past is not always a contraindication to reintroducing prophylaxis. The decision of prophylaxis avoidance should be analyzed carefully; in uncertain cases, a sulfonamide desensitization protocol should be considered.

Abstract 2063: Using the edge wells in 96-well plates without increasing variability in cytotoxicity assays through thermal controls

Abstract There are very few things as fundamental to cancer research as the 96-well-plate, yet edge effect has continued to cause problems since its introduction. The most common remedy for edge effect is to avoid using edge wells altogether, which eliminates 37% of the plate from the assay. If all of those wells could be used, an estimated USD $119M could be saved in research costs annually across the globe. We have shown previously that maintaining constant thermal control of plating conditions reduces variability in stem cell toxicity assays. Here, we ask the question: can we use the edge wells in cancer screening assays if we control thermal changes that happen in the traditional lab as cells are plated at room temperature and incubated at 37 degrees C? We had the null hypothesis that including the edge wells would add variability to an A549 cytotoxicity assay, even if the cell handling and incubation temperatures were matched and held constant. We plated A549 cells at either room temperature (like a BSC) or at 37 degrees C using the Xvivo System, which maintains constant temperature, oxygen, CO2, and relative humidity levels around cell handling operations. The cells were treated with serial dilutions of peracetic acid/hydrogen peroxide solution. After incubation for 3 days, the plates were stained with Crystal Violet and assessed for cell density (n=3 separate experiments). The null hypothesis was disproven. We found that if the plates were maintained at 37 degrees C during cell handling as well as incubation, that cell distribution was random and even across all wells, even edge wells. We found that there was no statistical difference between edge well and center well results in cytotoxicity assays. Edge wells were usable without increasing variability in the assays. This is consistent with earlier findings showing that when temperature changes between cell plating and incubation were averted, stem cell distribution across the plate was random and the edge effect was eliminated. Citation Format: Alicia D. Henn, Shannon Darou, Randy Yerden. Using the edge wells in 96-well plates without increasing variability in cytotoxicity assays through thermal controls [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2063.

Endotracheal Intubation via Tracheotomy and Subsequent Thoracotomy in Rats for Non-Survival Applications.

Endotracheal intubation and subsequent ventilation are often basic requirements for translational research in rat models for various interventions that require controlled or high ventilation pressures or access to the thoracic cavity and organs. Conventional endoorotracheal intubation using the anatomically existing route through the mouth is well suited for survival experiments. However, this procedure poses some challenges, including generally higher levels of the required experience and technical skill, more advanced equipment, and greater time effort with relevant intubation failure rates and complications such as tracheal perforation, temporary systemic hypooxygenation, and relevant aerial leakage. This manuscript, therefore, presents a detailed step-by-step protocol for endotracheal intubation through tracheotomy in non-survival rat models when guaranteed intubation success, constant oxygenation levels, high ventilation pressures, or open thoracotomy are required. The protocol emphasizes the importance of meticulous surgical technique to ensure consistent and reliable outcomes, especially for researchers who are inexperienced or lack routine in the technique of endoorotracheal intubation via direct laryngoscopy. This procedure is, therefore, expected to minimize animal suffering and unnecessary animal losses.

Optimization for diffusion-type oxygen supply nearby working face of railway tunnel in plateau

During the construction of railway tunnels in plateau environment regions, ensuring adequate oxygen supply is crucial for both worker health and safety, and tunnelling progress. Existing diffusion-type oxygen supply enrichments for plateau regions lack quantitative conclusions and have not been implemented systematically in actual engineering. To refine the design parameters of the required method, this study utilized computational fluid dynamics (CFD) to examine the optimal design parameters for oxygen supply equipment in a typical engineering project. The optimal scheme consisted of three rows of oxygen diffusion apparatuses with 0.07 m inlet diameter, 0.4 m lateral spacing and 60° tilt that maintain a constant oxygen supply rate. This configuration maximized oxygen concentration enrichment in workers’ breathing zones, with oxygen partial pressure in most target zones remaining below 3000 m altitude, except for the ventilation side where it was 3360 m. This study elucidated the effects of various design parameters on oxygen distribution and proposed the optimal combination for a typical tunnel engineering project. The findings provide a guidance for implementing diffusion-type oxygen enrichment in high-altitude tunnel construction, aiding both worker safety and project efficiency.

From the Modeling of an Electrochemical YSZ-Based Gas Sensor Used in Electrolysis Mode.

Electrochemical sensors have been used for many decades. However, the modeling of such sensors used in electrolysis mode is poorly documented, especially in the case of multiple gases' parallel actions. These are of great interest since they constitute the first brick to bring information on the natures and concentrations of gaseous mixture compositions, thanks to gray box modeling of sensor arrays, for example. Based on Butler-Volmer's equations, a model assuming parallel reactions at gold cathode has been introduced in this article and confronted with experimental results. The establishment of the model is based on the extraction of three variables: the charge transfer coefficient "α", the reaction order γ, and the reaction constant rate k0. Tests performed without pollutants and with different concentrations of oxygen could be nicely fitted using the model. The influence of the polarization current on the three variables of the model has been evaluated, showing a clear influence on the constant rate and the reaction order. Moreover, increasing the polarization current enabled us to obtain selectivity for oxidant gases. Similarly, the effect of the oxygen concentration was evaluated. Results showed that, in this case, the charge transfer coefficients "α" obtained for oxidant gases are quite different from the ones obtained in the polarization current varying conditions. Therefore, the model will be interesting in situations where polarization current and oxygen content are not varied together. Variation of polarization current can be quite interesting to obtain increased information for multivariate analysis purposes in constant oxygen content situations. Additionally, other parameters have to be considered for applications in which the oxygen content is bound to change, such as exhaust gases or combustion.

Effect of oxygen concentration, pressure, and opposed flow velocity on the flame spread along thin PMMA sheets

The flame spread of thin PMMA sheets has been studied both in opposed configuration under microgravity (9.3 s drop tower) and in downward configuration under normal gravity conditions. The position of the flame front has been determined with the help of an infrared camera. Propagation rates have been measured over a range of 30–200 mm/s forced opposed flow (only microgravity), 60–101.3 kPa ambient pressure, and oxygen concentrations of 21–35.4 vol. %, which corresponds to real environmental conditions on spacecraft. In addition to variations along the normoxic curve with constant oxygen partial pressure, the parameters oxygen and pressure were examined independently of each other in order to be able to determine their respective effects. The variation of the flow velocity was carried out at 60 kPa and 35.4 vol. % oxygen. The results for both microgravity and normal gravity are discussed separately on the basis of the respective atmospheric effect. Along the normoxic curve, a significant increase in the flame spread rate was found with increasing oxygen concentration and correspondingly decreasing pressure. This results in a significant increase in the risk of fire with regard to future exploration missions. The effect of the flow velocity cannot be neglected in the investigated velocity range and was linked to the influencing parameters in a correlation. Based on this parameterization, a linear function is given that reflects both the downward and the opposed results well. This function can be used to predict the flame spread in the given parameter space. Under normal gravity, the tested samples show a slightly increased propagation rate in most cases. This can essentially be attributed to the difference in velocity between the buoyant flow and the forced flow in µg.

Challenges of Using Fuel Cells to Deliver Aircraft Propulsion Power

Beside sustainable aviation fuels (SAFs), which offer an easy but expensive drop-in solution the use of hydrogen is discussed as an important way to decarbonise air traffic. According to a study performed by McKenzie on behalf of the “Fuel Cell and Hydrogen 2” and “Clean Sky 2” Joint undertakings hydrogen is the economical more viable option for small and medium range aircrafts1. For the smaller aircrafts electric propulsion using fuel cells to deliver the required electric power are the preferred choice from the economic perspective.Operating fuels cell on board of a flying aircraft is however not necessarily easy. An evident issue is the reduced air pressure at high altitudes. So, the barometric pressure at an altitude of 11,000 m is only 0.29 bar. Oxygen partial pressure is equally reduced to 61 mbar at constant oxygen concentration of 21 vol.%. In order to supply the stack either much higher flow rates are required at reduced pressures or a much higher compression. The former will create challenges regarding water management as a high gas flow in combination with reduced pressure accelerates the drying out of the membrane. Using HT-PEMFC instead would avoid the impact of water evaporation. However, the conditions are also likely to foster evaporation of phosphoric acid from the membrane electrode assembly. Here it will be investigate from published data if new HT-PEMFC membranes e.g. from Los Alamos National Laboratory2 would allow such a low pressure operation. Operating at high pressure will definitively challenge the system efficiency. Also, the characteristics of typical compressors render it difficult to achieve the required air compression rate of about 4.5 to increase pressure from 0.29 bar ambient to 1.3 bar stack pressure. This is, because during typical cruise operation power consumption and thus air need is strongly reduced.The variation of load and subsequently the likely variation of stack pressure can also cause challenges, in particular if after a period of low power requirements, a sudden increase in power demand needs to be answered. Such a situation will regularly be encountered for high load take off acceleration after taxying and potential waiting. Here hybridisation with a battery can be helpful to allow the fuel cell to power-up in time before take-off charging the battery used for electric taxying. More difficult is the irregular but for safety reason important situation of a go-around. During descend engines are typically operated at close to idle condition for a longer period of time. If no measures are taken to maintain stack temperature the temperature will reduce so that the immediate supply of power required for a go-around might not be available. Keeping the temperature at low load may however again cause dry-out or acid evaporation depending on whether the stack is LT- or HT-PEMFC based.In this contribution are more detailed analysis will be presented also striving to assign issues and their potential mitigation to component, stack or system level. Hydrogen-powered aviation: A fact-based study of hydrogen technology, economics, and climate impact by 205 0, Luxembourg, Publications Office of the European Union.K.-S. Lee, S. Maurya, Y. S. Kim, C. R. Kreller, M. S. Wilson, D. Larsen, S. E. Elangovan and R. Mukundan, Energy Environ. Sci., 11(4), 979–987 (2018).

A case of successful treatment of diffuse post-coronavirus pulmonary fibrosis with pirfenidone

IntroductionAccumulated evidence suggests that pulmonary fibrosis is a common complication of COVID-19. Fibrotic post-coronavirus lung changes are similar to the changes found in patients with idiopathic pulmonary fibrosis.AimThe paper describes the outcomes of pirfenidone usage in treatment of patients with post-coronavirus pulmonary fibrosis.Case studyThe paper presents a case study about a 51-year-old male patient, who had diffuse post-coronavirus pulmonary fibrosis with significant impairment of external respiratory function. The patient had experienced severe COVID-19 bilateral polysegmental pneumonia. In the 3rd week of the disease, multislice computed tomography detected signs of fibrosis that affected 80% of lung tissue. It was decided to start antifibrotic treatment with pirfenidone, which is usually used to treat idiopathic pulmonary fibrosis.Results and discussionPirfenidone was prescribed for 3 months according to the conventional scheme in combination with methylprednisolone. This therapy resulted in significant decrease of fibrosis scope , normalization of respiratory function and improvement of patient's quality of life. A key feature of the presented clinical case is a significant positive effect of pirfenidone in treating coronavirus-associated pulmonary fibrosis, which affected 80% of lung tissue of the patient.ConclusionsPost-coronavirus pulmonary fibrosis is characterized by the severe oxygen insufficiency and requires a constant oxygen support. The treatment that included pirfenidone in combination with steroids has demonstrated convincing positive effect. It reduces post-coronavirus pulmonary fibrosis and improves lung function.

Tracing fluid infiltration into oceanic crust up to ultra-high-pressure conditions

Fluid–rock interaction within the altered oceanic crust and across the slab–mantle boundary during subduction facilitates element transfer, but the dynamics of fluid transport and fluid–rock exchange during upward fluid migration are still unclear. A study of metamorphic fluid–rock interaction within a section of subducted oceanic crust was carried out on eclogites and metasediments of the ultra-high-pressure Lago di Cignana Unit (NW Italian Alps). The P–T modeling of a quartzschist shows that garnet grew during the prograde and sporadically during the retrograde path and that phengite mainly records the peak to retrograde conditions. Microscale geochemical analysis of garnets has revealed a systematic evolution of oxygen isotopic composition with garnet major element zonation, with extreme within-sample core–rim variations in δ18O between 18 and 4‰ providing evidence for external fluid influx. Garnet in eclogites and calcschists, as well as garnet cores in quartz-rich lithologies, shows normal compositional zoning, as expected for prograde garnet growth, and a relatively constant oxygen isotopic composition. The outer garnet growth zones within a few metasediments show reverse or discontinuous zoning and progressively lower δ18O. Despite major element zoning, the isotopic composition of mica is homogeneous across chemical zoning in one eclogite and one quartzschist, but shows 6‰ variability in another quartzschist. In the underlying Zermatt–Saas serpentinites, antigorite from nine serpentinite samples shows some variation in δ18O, with average δ18O values for individual samples ranging from 1 to 6‰. These results provide evidence for two main stages of external fluid infiltration: (i) fluids from the dehydration of mafic lithologies entered the sequence at peak conditions around 3 GPa, as indicated by the oxygen composition of intermediate zones of mica and garnet, and (ii) low δ18O fluids from serpentinites infiltrated parts of the sedimentary package during exhumation prior to 1.5 GPa, as recorded by the 4‰ garnet outer rims. Samples recording external fluid infiltration are concentrated in the lower part of the sequence, indicating channelized fluid flow, suggesting focused fluid infiltration due to permeability contrasts between metasedimentary and eclogitic lithologies. Channelized fluid flow in the ultra-high-pressure metasediments of Lago di Cignana has not resulted in systematic decarbonation of the metasediments.

From shake flask to bioreactor: Production of Salmonella Typhi porins as a typhoid vaccine candidate

Worldwide, Salmonella Typhi infections persist as an important health problem, accounting for about 9.4 million cases annually. Porins are one of the targets in the protective response against infection with Salmonella Typhi, a vaccine designed with these porins was shown to be safe in a phase 1 clinical trial eliciting a long-lasting response. In this work, an airlift bioreactor was designed and used to produce Salmonella Typhi biomass and purify porins. A comparison between the airlift bioreactor and shaken flasks biomass production rates was carried out considering a constant oxygen mass transfer coefficient. The analysis showed that the change in culture system does not affect the growth kinetic parameters, nor the maximum biomass production. The growth and substrate consumption kinetic parameters were estimated through mathematical models. Porins produced in the bioreactor induced equivalent humoral responses and protective capacity in mice compared to porins produced in shaken flasks. These results suggest that airlift bioreactors provide a promising platform for industrial production of porins.

Investigations for a Yarrowia-Based Biorefinery: In Vitro Proof-of-Concept for Manufacturing Sweetener, Cosmetic Ingredient, and Bioemulsifier

Yarrowia lipolytica is a widely used microorganism in biotechnology since it is capable of producing a wide range of products (lipase, citric acid, polyols). A less-studied related strain is Y. divulgata, which is also capable of erythritol production in even higher concentration than most Y. lipolytica wild strains from glycerol as renewable feedstock. Thus, the aim of this work was to investigate Y. divulgata’s complex utilisation based on erythritol fermentation from glycerol to establish a Yarrowia-based biorefinery in which both the fermentation broth and separated cells are converted into high added-value products (erythritol, bioemulsifier, cosmetic ingredient, i.e., skin moisturizer). An important parameter of erythritol fermentation is an adequate oxygen level, so both the constant oxygen level and oxygen absorption rate were investigated regarding the three target products. DO (dissolved oxygen) = 10, 20, 30, 40% was examined in the bioreactor, and a KLa range of 18–655 h−1 was investigated in both the bioreactor and in different types of shaking flasks, applying two different glycerol levels (100–150 g/L). The results showed that the Yarrowia divulagata NCAIM 1485 strain could produce one of the highest amounts of erythritol (44.14 ± 1 g/L) among wild-type yeasts from 150 g/L glycerol beside a KLa value of 655 h−1. Cell-lysates skin hydrating activity was the highest (12%) when DO = 20% (KLa 26.4 h−1) was applied. In all cases, the collected samples had an emulsification index above 69% which did not decrease below 54% after 24 h, showing good stability. Since Y. divulgata fermentations resulted in three high added-value products at the same time from a renewable raw material (glycerol), we concluded that it is suitable for complex utilisation in a microbial biorefinery, since the fermentation broth can be used for the isolation of a sweetener and bioemulsifier; meanwhile, the separated cells can be processed for cosmetic application as a skin moisturizer.