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1.
J Environ Sci (China) ; 148: 420-436, 2025 Feb.
Article in English | MEDLINE | ID: mdl-39095177

ABSTRACT

Mercury (Hg) pollution has been a global concern in recent decades, posing a significant threat to entire ecosystems and human health due to its cumulative toxicity, persistence, and transport in the atmosphere. The intense interaction between mercury and selenium has opened up a new field for studying mercury removal from industrial flue gas pollutants. Besides the advantages of good Hg° capture performance and low secondary pollution of the mineral selenium compounds, the most noteworthy is the relatively low regeneration temperature, allowing adsorbent regeneration with low energy consumption, thus reducing the utilization cost and enabling recovery of mercury resources. This paper reviews the recent progress of mineral selenium compounds in flue gas mercury removal, introduces in detail the different types of mineral selenium compounds studied in the field of mercury removal, reviews the adsorption performance of various mineral selenium compounds adsorbents on mercury and the influence of flue gas components, such as reaction temperature, air velocity, and other factors, and summarizes the adsorption mechanism of different fugitive forms of selenium species. Based on the current research progress, future studies should focus on the economic performance and the performance of different carriers and sizes of adsorbents for the removal of Hg0 and the correlation between the gas-particle flow characteristics and gas phase mass transfer with the performance of Hg0 removal in practical industrial applications. In addition, it remains a challenge to distinguish the oxidation and adsorption of Hg0 quantitatively.


Subject(s)
Air Pollutants , Mercury , Mercury/chemistry , Adsorption , Air Pollutants/chemistry , Selenium/chemistry , Gases/chemistry , Selenium Compounds/chemistry
2.
J Chem Phys ; 161(5)2024 Aug 07.
Article in English | MEDLINE | ID: mdl-39087548

ABSTRACT

In this study, peptides designed using fragments of an antifreeze protein (AFP) from the freeze-tolerant insect Tenebrio molitor, TmAFP, were evaluated as inhibitors of clathrate hydrate formation. It was found that these peptides exhibit inhibitory effects by both direct and indirect mechanisms. The direct mechanism involves the displacement of methane molecules by hydrophobic methyl groups from threonine residues, preventing their diffusion to the hydrate surface. The indirect mechanism is characterized by the formation of cylindrical gas bubbles, the morphology of which reduces the pressure difference at the bubble interface, thereby slowing methane transport. The transfer of methane to the hydrate interface is primarily dominated by gas bubbles in the presence of antifreeze peptides. Spherical bubbles facilitate methane migration and potentially accelerate hydrate formation; conversely, the promotion of a cylindrical bubble morphology by two of the designed systems was found to mitigate this effect, leading to slower methane transport and reduced hydrate growth. These findings provide valuable guidance for the design of effective peptide-based inhibitors of natural-gas hydrate formation with potential applications in the energy and environmental sectors.


Subject(s)
Antifreeze Proteins , Methane , Tenebrio , Water , Antifreeze Proteins/chemistry , Kinetics , Methane/chemistry , Methane/analogs & derivatives , Water/chemistry , Tenebrio/chemistry , Animals , Gases/chemistry , Peptides/chemistry , Peptides/pharmacology
3.
ACS Sens ; 9(7): 3741-3753, 2024 Jul 26.
Article in English | MEDLINE | ID: mdl-38996081

ABSTRACT

The persistent challenge of poor recovery characteristics of NO2 sensors operated at room temperature remains significant. However, the development of In2O3-based gas sensing materials provides a promising approach to accelerate response and recovery for sub-ppm of NO2 detection at room temperature. Herein, we propose a simple two-step method to synthesize a one-dimensional (1D) In2O3@ZnO heterostructure material with hollow microtubes, by coupling metal-organic frameworks (MOFs) (MIL-68 (In)) and zinc ions. Meanwhile, the In2O3@ZnO composite-based gas sensor exhibits superior sensitivity performance to NO2 under visible light activation. The response value to 5 ppm of NO2 at room temperature is as high as 1800, which is 35 times higher than that of the pure In2O3-based sensor. Additionally, the gas sensor based on the In2O3@ZnO heterostructure demonstrates a significantly reduced response/recovery time of 30 s/67 s compared to the sensor based on pure In2O3 (74 s/235 s). The outstanding gas sensing properties of the In2O3@ZnO heterostructure-based sensors can be attributed to the enhanced photogenerated charge separation efficiency resulting from the heterostructure effect, and the improved receptor function toward NO2, which can increase the reactive sites and gas adsorption capacity. In summary, this work proposes a low-cost and efficient method to synthesize a 1D heterostructure material with microtube structures, which can serve as a fundamental technique for developing high-performance room-temperature gas sensors.


Subject(s)
Indium , Light , Nitrogen Dioxide , Temperature , Zinc Oxide , Zinc Oxide/chemistry , Nitrogen Dioxide/analysis , Nitrogen Dioxide/chemistry , Indium/chemistry , Metal-Organic Frameworks/chemistry , Gases/analysis , Gases/chemistry
4.
ACS Sens ; 9(7): 3604-3615, 2024 Jul 26.
Article in English | MEDLINE | ID: mdl-39016238

ABSTRACT

Metal oxides with nanoarray structures have been demonstrated to be prospective materials for the design of gas sensors with high sensitivity. In this work, the WO3 nanoneedle array structures were synthesized by a one-step hydrothermal method and subsequent calcination. It was demonstrated that the calcination of the sample at 400 °C facilitated the construction of lilac-like multiple self-supporting WO3 arrays, with appropriate c/h-WO3 heterophase junction and highly oriented nanoneedles. Sensors with this structure exhibited the highest sensitivity (2305) to 100 ppm ethylene glycol at 160 °C and outstanding selectivity. The enhanced ethylene glycol gas sensing can be attributed to the abundant transport channels and active sites provided by this unique structure. In addition, the more oxygen adsorption caused by the heterophase junction and the aggregation of reaction medium induced by tip effect are both in favor of the improvement on the gas sensing performance.


Subject(s)
Ethylene Glycol , Nanostructures , Oxides , Tungsten , Tungsten/chemistry , Oxides/chemistry , Ethylene Glycol/chemistry , Nanostructures/chemistry , Gases/analysis , Gases/chemistry
6.
Environ Sci Pollut Res Int ; 31(32): 44669-44690, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38963632

ABSTRACT

Methyl mercaptan is a typical volatile organosulfur pollutant contained in many gases emitted by urban waste treatment, various industries, natural gas handling, refining processes, and energy production. This work is a comprehensive overview of the scientific and practical aspects related to the management of methyl mercaptan pollution. The main techniques, including absorption, adsorption, oxidation, and biological treatments, are examined in detail. For each method, its capability as well as the technical advantages and drawbacks have been highlighted. The emerging methods developed for the removal of methyl mercaptan from natural gas are also reviewed. These methods are based on the catalytic conversion of CH3SH to hydrocarbons and H2S.


Subject(s)
Gases , Sulfhydryl Compounds , Sulfhydryl Compounds/chemistry , Waste Management/methods , Air Pollutants
7.
Int J Mol Sci ; 25(13)2024 Jul 08.
Article in English | MEDLINE | ID: mdl-39000590

ABSTRACT

Protein cysteine S-glycosylation is a relatively rare and less well characterized post-translational modification (PTM). Creating reliable model proteins that carry this modification is challenging. The lack of available models or natural S-glycosylated proteins significantly hampers the development of mass-spectrometry-based (MS-based) methodologies for detecting protein cysteine S-glycosylation in real-world proteomic studies. There is also limited MS-sequencing data describing it as easier to create synthetic S-glycopeptides. Here, we present the results of an in-depth manual analysis of automatically annotated CID/HCD spectra for model S-glucopeptides. The CID spectra show a long series of y/b-fragment ions with retained S-glucosylation, regardless of the dominant m/z signals corresponding to neutral loss of 1,2-anhydroglucose from the precursor ions. In addition, the spectra show signals manifesting glucosyl transfer from the cysteine position onto lysine, arginine (Lys, Arg) side chains, and a peptide N-terminus. Other spectral evidence indicates that the N-glucosylated initial products of transfer are converted into N-fructosylated (i.e., glycated) structures due to Amadori rearrangement. We discuss the peculiar transfer of the glucose oxocarbenium ion (Glc+) to positively charged guanidinium residue (ArgH+) and propose a mechanism for the gas-phase Amadori rearrangement involving a 1,2-hydride ion shift.


Subject(s)
Cysteine , Glycosylation , Cysteine/chemistry , Cysteine/metabolism , Protein Processing, Post-Translational , Glycopeptides/chemistry , Glycopeptides/metabolism , Peptides/chemistry , Peptides/metabolism , Gases/metabolism , Gases/chemistry , Glucose/metabolism , Glucose/chemistry , Proteomics/methods , Tandem Mass Spectrometry/methods
8.
PLoS One ; 19(7): e0307110, 2024.
Article in English | MEDLINE | ID: mdl-38995946

ABSTRACT

The complex vibration phenomenon occurs in the downhole environment of the gas-liquid hydrocyclone, which affects the flow field in the hydrocyclone. In order to study the influence of vibration on hydrocyclone separation, the characteristics of the flow field in the downhole gas-liquid hydrocyclone were analyzed and studied under the condition of vibration coupling. Based on Computational Fluid Dynamics (CFD), Computational Solid Mechanics Method (CSM) and fluid-solid coupling method, a fluid-solid coupling mechanical model of a gas-liquid cyclone is established. It is found that under the condition of vibration coupling, the velocity components in the three directions of the hydrocyclone flow field change obviously. The peak values of tangential velocity and axial velocity decrease, and the asymmetry of radial velocity increases. The distribution regularity of vorticity and turbulence intensity in the overflow pipe becomes worse. Among them, the vorticity intensity of the overflow pipe is obviously enhanced, and the higher turbulence intensity near the wall occupies more area distribution range. The gas-liquid separation efficiency of the hydrocyclone will decrease with the increase of the rotational speed of the screw pump, and the degree of reduction can reach more than 10%. However, this effect will decrease with the increase of the rotational speed of the screw pump, so the excitation effect caused by the rotational speed has a maximum limit on the flow field.


Subject(s)
Gases , Vibration , Gases/chemistry , Hydrodynamics , Models, Theoretical , Computer Simulation
9.
RNA Biol ; 21(1): 1-6, 2024 Jan.
Article in English | MEDLINE | ID: mdl-39016047

ABSTRACT

Understanding how cells sense gases or gaseous solutes is a fundamental question in biology and is pivotal for the evolution of molecular and organismal life. In numerous organisms, gases can diffuse into cells, be transported, generated, and sensed. Controlling gases in the cellular environment is essential to prevent cellular and molecular damage due to interactions with gas-dependent free radicals. Consequently, the mechanisms governing acute gas sensing are evolutionarily conserved and have been experimentally elucidated in various organisms. However, the scientific literature on direct gas sensing is largely based on hemoprotein-based gasoreceptors (or sensors). As RNA-based G-quadruplex (G4) structures can also bind to heme, I propose that some ribozymes can act as gas-sensing riboceptors (ribonucleic acid receptors). Additionally, I present a few other ideas for non-heme metal ion- or metal cluster-based gas-sensing riboceptors. Studying riboceptors can help understand the evolutionary origins of cellular and gasocrine signaling.


Subject(s)
Gases , Animals , Humans , G-Quadruplexes , Gases/metabolism , Gases/chemistry , Heme/metabolism , Heme/chemistry , RNA, Catalytic/metabolism , Signal Transduction
10.
Anal Chem ; 96(28): 11549-11556, 2024 Jul 16.
Article in English | MEDLINE | ID: mdl-38958207

ABSTRACT

Human-borne acetone is a potent marker of lipid metabolism. Here, an enzyme immobilization method for secondary alcohol dehydrogenase (S-ADH), which is suitable for highly sensitive and selective biosensing of acetone, was developed, and then its applicability was demonstrated for spatiotemporal imaging of concentration distribution. After various investigations, S-ADH-immobilized meshes could be prepared with less than 5% variation by cross-linking S-ADH with glutaraldehyde on a cotton mesh at 40 °C for 15 min. Furthermore, high activity was obtained by adjusting the concentration of the coenzyme nicotinamide adenine dinucleotide (NADH) solution added to the S-ADH-immobilized mesh to 500 µM and the solvent to a potassium phosphate buffer solution at pH 6.5. The gas imaging system using the S-ADH-immobilized mesh was able to image the decrease in NADH fluorescence (ex 340 nm, fl 490 nm) caused by the catalytic reaction of S-ADH and the acetone distribution in the concentration range of 0.1-10 ppm-v, including the breath concentration of healthy people at rest. The exhaled breath of two healthy subjects at 6 h of fasting was quantified as 377 and 673 ppb-v, which were consistent with the values quantified by gas chromatography-mass spectrometry.


Subject(s)
Acetone , Breath Tests , Enzymes, Immobilized , Acetone/analysis , Acetone/chemistry , Humans , Enzymes, Immobilized/chemistry , Enzymes, Immobilized/metabolism , Biosensing Techniques , Alcohol Oxidoreductases/chemistry , Alcohol Oxidoreductases/metabolism , Gases/chemistry , Gases/analysis , Exhalation , NAD/analysis , NAD/chemistry , NAD/metabolism
11.
BMC Urol ; 24(1): 139, 2024 Jul 04.
Article in English | MEDLINE | ID: mdl-38965501

ABSTRACT

BACKGROUND: An intravesical gas explosion is a rare complication of transurethral resection of the prostate (TURP). It was first reported in English literature in 1926, and up to 2022 were only forty-one cases. Injury from an intravesical gas explosion, in the most severe cases appearing as extraperitoneal or intraperitoneal bladder rupture needed emergent repair surgery. CASE PRESENTATION: We present a case of a 75-year-old man who suffered an intravesical gas explosion during TURP. The patient underwent an emergent exploratory laparotomy for bladder repair and was transferred to the intensive care unit for further observation and treatment. Under the medical team's care for up to sixty days, the patient recovered smoothly without clinical sequelae. CONCLUSIONS: This case report presents an example of a rare complication of intravesical gas explosion during TURP, utilizing root cause analysis (RCA) to comprehend causal relationships and team strategies and tools to improve performance and patient safety (TeamSTEPPS) method delivers four teamwork skills that can be utilized during surgery and five recommendations to avoid gas explosions during TURP to prevent the recurrence of medical errors. In modern healthcare systems, promoting patient safety is crucial. Once complications appear, RCA and TeamSTEPPS are helpful means to support the healthcare team reflect and improve as a team.


Subject(s)
Explosions , Root Cause Analysis , Transurethral Resection of Prostate , Urinary Bladder , Humans , Male , Aged , Transurethral Resection of Prostate/adverse effects , Urinary Bladder/surgery , Urinary Bladder/injuries , Gases , Patient Care Team , Intraoperative Complications/etiology
12.
ACS Sens ; 9(7): 3641-3651, 2024 Jul 26.
Article in English | MEDLINE | ID: mdl-38967239

ABSTRACT

Limited by insufficient active sites and restricted mechanical strength, designing reliable and wearable gas sensors with high activity and ductility remains a challenge for detecting hazardous gases. In this work, a thermally induced and solvent-assisted oxyanion etching strategy was implemented for selective pore opening in a rigid microporous Cu-based metal-organic framework (referred to as CuM). A conductive CuM/MXene aerogel was then self-assembled through cooperative hydrogen bonding interactions between the carbonyl oxygen atom in PVP grafted on the surface of defect-rich Cu-BTC and the surface functional hydroxyl group on MXene. A flexible NO2 sensing performance using the CuM/MXene aerogel hybridized sodium alginate hydrogel is finally achieved, demonstrating extraordinary sensitivity (S = 52.47 toward 50 ppm of NO2), good selectivity, and rapid response/recovery time (0.9/4.5 s) at room temperature. Compared with commercial sensors, the relative error is less than 7.7%, thereby exhibiting significant potential for application in monitoring toxic and harmful gases. This work not only provides insights for guiding rational synthesis of ideal structure models from MOF composites but also inspires the development of high-performance flexible gas sensors for potential multiscenario applications.


Subject(s)
Hydrogen Bonding , Metal-Organic Frameworks , Temperature , Metal-Organic Frameworks/chemistry , Gels/chemistry , Nitrogen Dioxide/analysis , Nitrogen Dioxide/chemistry , Copper/chemistry , Gases/chemistry , Gases/analysis , Alginates/chemistry
13.
Molecules ; 29(14)2024 Jul 18.
Article in English | MEDLINE | ID: mdl-39064946

ABSTRACT

Chlorella sorokiniana, isolated from a pond adjacent to a cement plant, was cultured using flue gas collected directly from kiln emissions using 20 L and 25000 L photobioreactors. Lipids, proteins, and polysaccharides were analyzed to understand their overall composition for potential applications. The lipid content ranged from 17.97% to 21.54% of the dry biomass, with carotenoid concentrations between 8.4 and 9.2 mg/g. Lutein accounted for 55% of the total carotenoids. LC/MS analysis led to the identification of 71 intact triacylglycerols, 8 lysophosphatidylcholines, 10 phosphatidylcholines, 9 monogalactosyldiacylglycerols, 12 digalactosyldiacylglycerols, and 1 sulfoquinovosyl diacylglycerol. Palmitic acid, oleic acid, linoleic acid, and α-linolenic acid were the main fatty acids. Polyunsaturated fatty acid covers ≥ 56% of total fatty acids. Protein isolates and polysaccharides were also extracted. Protein purity was determined to be ≥75% by amino acid analysis, with all essential amino acids present. Monomer analysis of polysaccharides suggested that they are composed of mainly D-(+)-mannose, D-(+)-galactose, and D-(+)-glucose. The results demonstrate that there is no adverse effect on the metabolite profile of C. sorokiniana biomass cultured using flue gas as the primary carbon source, revealing the possibility of utilizing such algal biomass in industrial applications such as animal feed, sources of cosmeceuticals, and as biofuel.


Subject(s)
Biomass , Carbon , Chlorella , Fatty Acids , Chlorella/metabolism , Chlorella/growth & development , Chlorella/chemistry , Fatty Acids/analysis , Fatty Acids/metabolism , Carbon/chemistry , Polysaccharides/chemistry , Polysaccharides/analysis , alpha-Linolenic Acid/analysis , alpha-Linolenic Acid/metabolism , Gases/chemistry , Linoleic Acid/analysis , Linoleic Acid/metabolism , Lipids/analysis , Lipids/chemistry , Galactolipids/analysis , Galactolipids/metabolism , Carotenoids/analysis , Carotenoids/metabolism , Oleic Acid/analysis
14.
Sci Rep ; 14(1): 16529, 2024 07 17.
Article in English | MEDLINE | ID: mdl-39019921

ABSTRACT

Flue gas emissions are the waste gases produced during the combustion of fuel in industrial processes, which are released into the atmosphere. These identical processes also produce a significant amount of wastewater that is released into the environment. The current investigation aims to assess the viability of simultaneously mitigating flue gas emissions and remediating wastewater in a bubble column bioreactor utilizing bacterial consortia. A comparative study was done on different growth media prepared using wastewater. The highest biomass yield of 3.66 g L-1 was achieved with the highest removal efficiencies of 89.80, 77.30, and 80.77% for CO2, SO2, and NO, respectively. The study investigated pH, salinity, dissolved oxygen, and biochemical and chemical oxygen demand to assess their influence on the process. The nutrient balance validated the ability of bacteria to utilize compounds in flue gas and wastewater for biomass production. The Fourier Transform-Infrared Spectrometry (FT-IR) and Gas Chromatography-Mass Spectrometry (GC-MS) analyses detected commercial-use long-chain hydrocarbons, fatty alcohols, carboxylic acids, and esters in the biomass samples. The nuclear magnetic resonance (NMR) metabolomics detected the potential mechanism pathways followed by the bacteria for mitigation. The techno-economic assessment determined a feasible total capital investment of 245.74$ to operate the reactor for 288 h. The bioreactor's practicability was determined by mass transfer and thermodynamics assessment. Therefore, this study introduces a novel approach that utilizes bacteria and a bioreactor to mitigate flue gas and remediate wastewater.


Subject(s)
Biodegradation, Environmental , Biomass , Bioreactors , Wastewater , Wastewater/microbiology , Wastewater/chemistry , Bioreactors/microbiology , Bacteria/metabolism , Bacteria/growth & development , Gases/metabolism , Spectroscopy, Fourier Transform Infrared , Gas Chromatography-Mass Spectrometry
15.
ACS Sens ; 9(7): 3707-3719, 2024 Jul 26.
Article in English | MEDLINE | ID: mdl-38985951

ABSTRACT

Gas sensors based on ambipolar materials offer significant advantages in reducing the size of the analytical system and enhancing its efficiency. Here, bilayer heterojunction devices are constructed using different octafluorinated phthalocyanine complexes, with Zn and Co as metal centers, combined with a lutetium bisphthalocyanine complex (LuPc2). Stable p-type behavior is observed for the ZnF8Pc/LuPc2 device under both electron-donating (NH3) and -oxidizing (NO2 and O3) gaseous species, while the CoF8Pc/LuPc2 device exhibits n-type behavior under reducing gases and p-type behavior under oxidizing gases. The nature of majority of the charge carriers of Co-based devices varies depending on the nature of target gases, displaying an ambipolar behavior. Both heterojunction devices demonstrate stable and observable response toward all three toxic gases in the sub-ppm range. Remarkably, the Co-based device is highly sensitive toward ammonia with a limit of detection (LOD) of 200 ppb, whereas the Zn-based device demonstrates exceptional sensitivity toward oxidizing gases, with excellent LOD values of 4.9 and 0.75 ppb toward NO2 and O3, respectively, which makes it one of the most effective organic heterojunction sensors reported so far for oxidizing gases.


Subject(s)
Gases , Indoles , Zinc , Indoles/chemistry , Gases/analysis , Gases/chemistry , Zinc/chemistry , Zinc/analysis , Isoindoles , Limit of Detection , Cobalt/chemistry , Lutetium/chemistry , Ammonia/analysis , Nitrogen Dioxide/analysis , Nitrogen Dioxide/chemistry , Organometallic Compounds/chemistry , Air Pollutants/analysis
16.
ACS Sens ; 9(7): 3531-3539, 2024 Jul 26.
Article in English | MEDLINE | ID: mdl-38996224

ABSTRACT

Metal-organic frameworks (MOFs) are a promising class of porous materials for the design of gas sensing arrays, which are often called electronic noses. Due to their chemical and structural tunability, MOFs are a highly diverse class of materials that align well with the similarly diverse class of volatile organic compounds (VOCs) of interest in many gas detection applications. In principle, by choosing the right combination of cross-sensitive MOFs, layered on appropriate signal transducers, one can design an array that yields detailed information about the composition of a complex gas mixture. However, despite the vast number of MOFs from which one can choose, gas sensing arrays that rely too heavily on distinct chemistries can be impractical from the cost and complexity perspective. On the other hand, it is difficult for small arrays to have the desired selectivity and sensitivity for challenging sensing applications, such as detecting weakly adsorbing gases with weak signals, or conversely, strongly adsorbing gases that readily saturate MOF pores. In this work, we employed gas adsorption simulations to explore the use of a variable pressure sensing array as a means of improving both sensitivity and selectivity as well as increasing the information content provided by each array. We studied nine different MOFs (HKUST-1, IRMOF-1, MgMOF-74, MOF-177, MOF-801, NU-100, NU-125, UiO-66, and ZIF-8) and four different gas mixtures, each containing nitrogen, oxygen, carbon dioxide, and exactly one of the hydrogen, methane, hydrogen sulfide, or benzene. We found that by lowering the pressure, we can limit the saturation of MOFs, and by raising the pressure, we can concentrate weakly adsorbing gases, in both cases, improving gas detection with the resulting arrays. In many cases, changing the system pressure yielded a better improvement in performance (as measured by the Kullback-Liebler divergence of gas composition probability distributions) than including additional MOFs. We thus demonstrated and quantified how sensing at multiple pressures can increase information content and cross-sensitivity in MOF-based arrays while limiting the number of unique materials needed in the device.


Subject(s)
Metal-Organic Frameworks , Metal-Organic Frameworks/chemistry , Gases/analysis , Gases/chemistry , Volatile Organic Compounds/analysis , Adsorption , Pressure
17.
Molecules ; 29(11)2024 Jun 04.
Article in English | MEDLINE | ID: mdl-38893534

ABSTRACT

Electrocatalytic CO2 reduction to CO and formate can be coupled to gas fermentation with anaerobic microorganisms. In combination with a competing hydrogen evolution reaction in the cathode in aqueous medium, the in situ, electrocatalytic produced syngas components can be converted by an acetogenic bacterium, such as Clostridium ragsdalei, into acetate, ethanol, and 2,3-butanediol. In order to study the simultaneous conversion of CO, CO2, and formate together with H2 with C. ragsdalei, fed-batch processes were conducted with continuous gassing using a fully controlled stirred tank bioreactor. Formate was added continuously, and various initial CO partial pressures (pCO0) were applied. C. ragsdalei utilized CO as the favored substrate for growth and product formation, but below a partial pressure of 30 mbar CO in the bioreactor, a simultaneous CO2/H2 conversion was observed. Formate supplementation enabled 20-50% higher growth rates independent of the partial pressure of CO and improved the acetate and 2,3-butanediol production. Finally, the reaction conditions were identified, allowing the parallel CO, CO2, formate, and H2 consumption with C. ragsdalei at a limiting CO partial pressure below 30 mbar, pH 5.5, n = 1200 min-1, and T = 32 °C. Thus, improved carbon and electron conversion is possible to establish efficient and sustainable processes with acetogenic bacteria, as shown in the example of C. ragsdalei.


Subject(s)
Bioreactors , Butylene Glycols , Carbon Dioxide , Carbon Monoxide , Clostridium , Fermentation , Formates , Hydrogen , Formates/metabolism , Formates/chemistry , Clostridium/metabolism , Clostridium/growth & development , Carbon Monoxide/metabolism , Hydrogen/metabolism , Carbon Dioxide/metabolism , Butylene Glycols/metabolism , Butylene Glycols/chemistry , Gases/metabolism , Gases/chemistry , Ethanol/metabolism
18.
Int J Mol Sci ; 25(11)2024 May 23.
Article in English | MEDLINE | ID: mdl-38891873

ABSTRACT

Gas-loaded nanocarriers (G-LN) show promise in improving heart transplantation (HTx) outcomes. Given their success in reducing cell death during normothermic hypoxia/reoxygenation (H/R) in vitro, we tested their integration into cardioplegic solutions and static cold storage (SCS) during simulated HTx. Wistar rat hearts underwent four hours of SCS with four G-LN variants: O2- or N2-cyclic-nigerosyl-nigerose-nanomonomers (CNN), and O2- or N2-cyclic-nigerosyl-nigerose-nanosponges (CNN-NS). We monitored physiological-hemodynamic parameters and molecular markers during reperfusion to assess cell damage/protection. Hearts treated with nanomonomers (N2-CNN or O2-CNN) showed improvements in left ventricular developed pressure (LVDP) and a trend towards faster recovery of the rate pressure product (RPP) compared to controls. However, nanosponges (N2-CNN-NS or O2-CNN-NS) did not show similar improvements. None of the groups exhibited an increase in diastolic left ventricular pressure (contracture index) during reperfusion. Redox markers and apoptosis/autophagy pathways indicated an increase in Beclin 1 for O2-CNN and in p22phox for N2-CNN, suggesting alterations in autophagy and the redox environment during late reperfusion, which might explain the gradual decline in heart performance. The study highlights the potential of nanomonomers to improve early cardiac performance and mitigate cold/H/R-induced stunning in HTx. These early improvements suggest a promising avenue for increasing HTx success. Nevertheless, further research and optimization are needed before clinical application.


Subject(s)
Heart Transplantation , Rats, Wistar , Animals , Heart Transplantation/methods , Rats , Male , Nanoparticles/chemistry , Oxygen/metabolism , Hypoxia/metabolism , Hemodynamics , Autophagy/drug effects , Apoptosis/drug effects , Gases/chemistry
19.
ACS Synth Biol ; 13(6): 1893-1905, 2024 Jun 21.
Article in English | MEDLINE | ID: mdl-38825826

ABSTRACT

Gas-fermenting Clostridium species hold tremendous promise for one-carbon biomanufacturing. To unlock their full potential, it is crucial to unravel and optimize the intricate regulatory networks that govern these organisms; however, this aspect is currently underexplored. In this study, we employed pooled CRISPR interference (CRISPRi) screening to uncover a wide range of functional transcription factors (TFs) in Clostridium ljungdahlii, a representative species of gas-fermenting Clostridium, with a special focus on TFs associated with the utilization of carbon resources. Among the 425 TF candidates, we identified 75 and 68 TF genes affecting the heterotrophic and autotrophic growth of C. ljungdahlii, respectively. We focused our attention on two of the screened TFs, NrdR and DeoR, and revealed their pivotal roles in the regulation of deoxyribonucleoside triphosphates (dNTPs) supply, carbon fixation, and product synthesis in C. ljungdahlii, thereby influencing the strain performance in gas fermentation. Based on this, we proceeded to optimize the expression of deoR in C. ljungdahlii by adjusting its promoter strength, leading to an improved growth rate and ethanol synthesis of C. ljungdahlii when utilizing syngas. This study highlights the effectiveness of pooled CRISPRi screening in gas-fermenting Clostridium species, expanding the horizons for functional genomic research in these industrially important bacteria.


Subject(s)
CRISPR-Cas Systems , Clostridium , Fermentation , Transcription Factors , Clostridium/genetics , Clostridium/metabolism , Transcription Factors/genetics , Transcription Factors/metabolism , CRISPR-Cas Systems/genetics , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Promoter Regions, Genetic/genetics , Clustered Regularly Interspaced Short Palindromic Repeats/genetics , Metabolic Engineering/methods , Gases/metabolism
20.
ACS Appl Mater Interfaces ; 16(24): 30755-30765, 2024 Jun 19.
Article in English | MEDLINE | ID: mdl-38847111

ABSTRACT

In recent years, enveloped micro-nanobubbles have garnered significant attention in research due to their commendable stability, biocompatibility, and other notable properties. Currently, the preparation methods of enveloped micro-nanobubbles have limitations such as complicated preparation process, large bubble size, wide distribution range, low yield, etc. There exists an urgent demand to devise a simple and efficient method for the preparation of enveloped micro-nanobubbles, ensuring both high concentration and a uniform particle size distribution. Magnetic lipid bubbles (MLBs) are a multifunctional type of enveloped micro-nanobubble combining magnetic nanoparticles with lipid-coated bubbles. In this study, MLBs are prepared simply and efficiently by a magneto internal heat bubble generation process based on the interfacial self-assembly of iron oxide nanoparticles induced by the thermogenic effect in an alternating magnetic field. The mean hydrodynamic diameter of the MLBs obtained was 384.9 ± 8.5 nm, with a polydispersity index (PDI) of 0.248 ± 0.021, a zeta potential of -30.5 ± 1.0 mV, and a concentration of (7.92 ± 0.46) × 109 bubbles/mL. Electron microscopy results show that the MLBs have a regular spherical stable core-shell structure. The superparamagnetic iron oxide nanoparticles (SPIONs) and phospholipid layers adsorbed around the spherical gas nuclei of the MLBs, leading the particles to demonstrate commendable superparamagnetic and magnetic properties. In addition, the effects of process parameters on the morphology of MLBs, including phospholipid concentration, phospholipid proportiona, current intensity, magnetothermal time, and SPION concentration, were investigated and discussed to achieve controlled preparation of MLBs. In vitro imaging results reveal that the higher the concentration of MLBs loaded with iron oxide nanoparticles, the better the in vitro ultrasound (US) imaging and magnetic resonance imaging (MRI) results. This study proves that the magneto internal heat bubble generation process is a simple and efficient technique for preparing MLBs with high concentration, regular structure, and commendable properties. These findings lay a robust foundation for the mass production and application of enveloped micro-nanobubbles, particularly in biomedical fields and other related domains.


Subject(s)
Phospholipids , Phospholipids/chemistry , Particle Size , Magnetic Iron Oxide Nanoparticles/chemistry , Magnetite Nanoparticles/chemistry , Gases/chemistry , Microbubbles , Magnetic Fields
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