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Frontiers in Microbiology 2024Microbial inhibition by high ammonia concentrations is a recurring problem that significantly restricts methane formation from intermediate acids, i.e., propionate and...
Microbial inhibition by high ammonia concentrations is a recurring problem that significantly restricts methane formation from intermediate acids, i.e., propionate and acetate, during anaerobic digestion of protein-rich waste material. Studying the syntrophic communities that perform acid conversion is challenging, due to their relatively low abundance within the microbial communities typically found in biogas processes and disruption of their cooperative behavior in pure cultures. To overcome these limitations, this study examined growth parameters and microbial community dynamics of highly enriched mesophilic and ammonia-tolerant syntrophic propionate and acetate-oxidizing communities and analyzed their metabolic activity and cooperative behavior using metagenomic and metatranscriptomic approaches. Cultivation in batch set-up demonstrated biphasic utilization of propionate, wherein acetate accumulated and underwent oxidation before complete degradation of propionate. Three key species for syntrophic acid degradation were inferred from genomic sequence information and gene expression: a syntrophic propionate-oxidizing bacterium (SPOB) " Syntrophopropionicum ammoniitolerans", a syntrophic acetate-oxidizing bacterium (SAOB) and a novel hydrogenotrophic methanogen, for which we propose the provisional name " Methanoculleus ammoniitolerans". The results revealed consistent transcriptional profiles of the SAOB and the methanogen both during propionate and acetate oxidation, regardless of the presence of an active propionate oxidizer. Gene expression indicated versatile capabilities of the two syntrophic bacteria, utilizing both molecular hydrogen and formate as an outlet for reducing equivalents formed during acid oxidation, while conserving energy through build-up of sodium/proton motive force. The methanogen used hydrogen and formate as electron sources. Furthermore, results of the present study provided a framework for future research into ammonia tolerance, mobility, aggregate formation and interspecies cooperation.
PubMed: 38933034
DOI: 10.3389/fmicb.2024.1389257 -
Pharmaceuticals (Basel, Switzerland) May 2024Selective COX-1 inhibitors are preferential therapeutic targets for platelet aggregation and clotting responses. In this study, we examined the selective...
Selective COX-1 inhibitors are preferential therapeutic targets for platelet aggregation and clotting responses. In this study, we examined the selective COX-1-inhibitory activities of four newly synthesized compounds, -, along with their abilities to inhibit platelet aggregation against ADP and collagen. The target compounds - were synthesized using the conventional method, sonication, and microwave-assisted methods. Microanalytical and spectral data were utilized to elucidate the structures of the new compounds -. Additionally, a spectral NMR experiment [NOESY] was conducted to emphasize the configuration around the double bond of the imine group C=N. The obtained results revealed no observed correlation between any of the neighboring protons, suggesting that the configuration at the C=N double bond is . Biological results revealed that all the screened compounds - might serve as selective COX-1 inhibitors. They showed IC values ranging from 0.71 μM to 4.82 μM against COX-1 and IC values ranging from 9.26 μM to 15.24 μM against COX-2. Their COX-1 selectivity indices ranged between 2.87 and 18.69. These compounds show promise as promising anti-platelet aggregation agents. They effectively prevented platelet aggregation induced by ADP with IC values ranging from 0.11 μM to 0.37 μM, surpassing the standard aspirin with an IC value of 0.49 μM. Additionally, they inhibited the platelet aggregation induced by collagen with IC values ranging from 0.12 μM to 1.03 μM, demonstrating superior efficacy compared to aspirin, which has an IC value of 0.51 μM. In silico molecular modeling was performed for all the target compounds within the active sites of COX-1 and COX-2 to rationalize their selective inhibitory activities towards COX-1. It was found that the binding interactions of the designed compounds within the COX-1 active site had remained unaffected by the presence of celecoxib. Molecular modeling and DFT calculations using the B3LYP/6-31+G (d,p) level were performed to study the stability of -forms with respect to -forms for the investigated compounds. A strong correlation was observed between the experimental observations and the quantum chemical descriptors.
PubMed: 38931377
DOI: 10.3390/ph17060710 -
Pharmaceuticals (Basel, Switzerland) May 2024Novel potassium-competitive acid blockers (P-CABs) have emerged as effective acid-suppressive drugs in recent years, replacing proton pump inhibitors (PPIs). We aim to... (Review)
Review
Comparative Efficacy and Safety of Potassium-Competitive Acid Blockers vs. Proton Pump Inhibitors for Peptic Ulcer with or without Infection: A Systematic Review and Network Meta-Analysis.
Novel potassium-competitive acid blockers (P-CABs) have emerged as effective acid-suppressive drugs in recent years, replacing proton pump inhibitors (PPIs). We aim to compare the efficacy and safety of P-CABs versus PPIs in the treatment of peptic ulcers with or without () infection. We searched in PubMed, Embase, WOS, Cochrane Library, ClinicalTrials.gov, CNKI, and Wanfang databases (all years up to January 2024). Efficacy and safety outcomes were evaluated using odds ratio (OR) and 95% confidence intervals (CI). The Surface Under the Cumulative Ranking (SUCRA) probabilities were used to rank each intervention. Among 14,056 studies screened, 56 studies involving 9792 participants were analyzed. Vonoprazan demonstrated the best efficacy in ulcer healing rate and eradication rate (SUCRA = 86.4% and 90.7%, respectively). Keverprazan ranked second in ulcer healing rates (SUCRA = 76.0%) and was more effective in pain remission rates (SUCRA = 91.7%). The risk of adverse events was low for keverprazan (SUCRA = 11.8%) and tegoprazan (SUCRA = 12.9%), and moderate risk for vonoprazan (SUCRA = 44.3%) was demonstrated. Compared to lansoprazole, vonoprazan exhibited a higher risk of drug-related adverse events (OR: 2.15; 95% CI: 1.60-2.89) and serious adverse events (OR: 2.22; 95% CI: 1.11-4.42). Subgroup analysis on patients with -positive peptic ulcers showed that vonoprazan was at the top of the SUCRA rankings, followed by keverprazan. Vonoprazan showed superior performance in peptic ulcers, especially for patients with -positive peptic ulcers. However, the risk of adverse events associated with vonoprazan should be noted. Keverprazan has also shown good therapeutic outcomes and has performed better in terms of safety.
PubMed: 38931366
DOI: 10.3390/ph17060698 -
Nutrients Jun 2024Iron deficiency remains a public health challenge globally. Prebiotics have the potential to improve iron bioavailability by modulating intestinal bacterial population,...
Iron deficiency remains a public health challenge globally. Prebiotics have the potential to improve iron bioavailability by modulating intestinal bacterial population, increasing SCFA production, and stimulating expression of brush border membrane (BBM) iron transport proteins among iron-deficient populations. This study intended to investigate the potential effects of soluble extracts from the cotyledon and seed coat of three pea () varieties (CDC Striker, CDC Dakota, and CDC Meadow) on the expression of BBM iron-related proteins (DCYTB and DMT1) and populations of beneficial intestinal bacteria in vivo using the model by oral gavage (one day old chicks) with 1 mL of 50 mg/mL pea soluble extract solutions. The seed coat treatment groups increased the relative abundance of compared to the cotyledon treatment groups, with CDC Dakota seed coat (dark brown pigmented) recording the highest relative abundance of . In contrast, CDC Striker Cotyledon (dark-green-pigmented) significantly increased the relative abundance of ( < 0.05). Subsequently, the two dark-pigmented treatment groups (CDC Striker Cotyledon and CDC Dakota seed coats) recorded the highest expression of DCYTB. Our study suggests that soluble extracts from the pea seed coat and dark-pigmented pea cotyledon may improve iron bioavailability by affecting intestinal bacterial populations.
Topics: Animals; Pisum sativum; Chickens; Prebiotics; Gastrointestinal Microbiome; Iron; Plant Extracts; Intestines; Seeds; Bifidobacterium; Cotyledon; Lactobacillus; Cation Transport Proteins
PubMed: 38931211
DOI: 10.3390/nu16121856 -
Plants (Basel, Switzerland) Jun 2024is an important vegetable, and its quality is affected by salt stress. () contribute to plant development and tolerance to salt stress. In this study, 35 genes were...
is an important vegetable, and its quality is affected by salt stress. () contribute to plant development and tolerance to salt stress. In this study, 35 genes were identified from a genome database for , including 9 , 5 , and 21 genes. Furthermore, in , the expression levels of most genes were higher at a low salinity level (50 or 100 mM NaCl) than in the control or 200 mM NaCl treatment. Levels of most genes were elevated in the stem. Moreover, was homologous to , which is involved in the regulation of sodium homeostasis and salt stress response. After overexpression in , seed germination was better, and the flowering time was earlier than that of wild-type plants. Additionally, the overexpression of in improved salt tolerance. These results reveal the roles of genes under salt stress and provide valuable information on this gene family in amaranth.
PubMed: 38931134
DOI: 10.3390/plants13121701 -
Molecules (Basel, Switzerland) Jun 2024Homogeneous catalysis involving a transition metal agostic interaction (TMHC) is an attractive strategy for C-H bond activation, in which the transition metal agostic...
Homogeneous catalysis involving a transition metal agostic interaction (TMHC) is an attractive strategy for C-H bond activation, in which the transition metal agostic intermediates serve as the critical component. To investigate the roles of manganese agostic intermediates in the unusual migration of the Mn(CO) fragment in the (exo-phenyl)(η-cyclohexenyl)manganese tricarbonyl [(Ph)(η-CH)Mn(CO)] (complex ) under the protonation of tetrafluoroboric acid-diethyl ether (HBF.EtO), a comprehensive density functional theory (DFT) theoretical study was performed. The computational results showed that formation of the [(cyclohex-3-enyl)-η-benzene]manganese tricarbonyl complex [(CH)(η-Ph)Mn(CO)][BF] (complex ) was achieved via a series of mono-agostic and di-agostic intermediates. The overall rate-limiting step for this unusual migration of the Mn(CO) fragment is the formation of the di-agostic (η-phenyl)manganese complex ( → → ) with a Gibbs barrier of 15.4 kcal mol. The agostic intermediates with TMHC agostic interactions were well-characterized by geometry parameters, Atoms-In-Molecules (AIM) analyses, and the Natural Adaptive Orbitals (NAdOs). The located pathways in the current study successfully explained the experimental observations, and the findings on the TMHC agostic interaction provided a new aspect of the catalytic reaction with the manganese complex.
PubMed: 38931010
DOI: 10.3390/molecules29122945 -
Molecules (Basel, Switzerland) Jun 2024Fuel cells are at the forefront of modern energy research, with graphene-based materials emerging as key enhancers of performance. This overview explores recent... (Review)
Review
Fuel cells are at the forefront of modern energy research, with graphene-based materials emerging as key enhancers of performance. This overview explores recent advancements in graphene-based cathode materials for fuel cell applications. Graphene's large surface area and excellent electrical conductivity and mechanical strength make it ideal for use in different solid oxide fuel cells (SOFCs) as well as proton exchange membrane fuel cells (PEMFCs). This review covers various forms of graphene, including graphene oxide (GO), reduced graphene oxide (rGO), and doped graphene, highlighting their unique attributes and catalytic contributions. It also examines the effects of structural modifications, doping, and functional group integrations on the electrochemical properties and durability of graphene-based cathodes. Additionally, we address the thermal stability challenges of graphene derivatives at high SOFC operating temperatures, suggesting potential solutions and future research directions. This analysis underscores the transformative potential of graphene-based materials in advancing fuel cell technology, aiming for more efficient, cost-effective, and durable energy systems.
PubMed: 38931001
DOI: 10.3390/molecules29122937 -
Molecules (Basel, Switzerland) Jun 2024Electrochemical nitrate reduction (NORR) has been recognized as a promising strategy for sustainable ammonia (NH) production due to its environmental friendliness and...
Electrochemical nitrate reduction (NORR) has been recognized as a promising strategy for sustainable ammonia (NH) production due to its environmental friendliness and economical nature. However, the NORR reaction involves an eight-electron coupled proton transfer process with many by-products and low Faraday efficiency. In this work, a molybdenum oxide (MoO)-decorated titanium dioxide nanotube on Ti foil (Mo/TiO) was prepared by means of an electrodeposition and calcination process. The structure of MoO can be controlled by regulating the concentration of molybdate during the electrodeposition process, which can further influence the electron transfer from Ti to Mo atoms, and enhance the binding energy of intermediate species in NORR. The optimized Mo/TiO-M with more Mo(IV) sites exhibited a better activity for NORR. The Mo/TiO-M electrode delivered a NH yield of 5.18 mg h cm at -1.7 V vs. Ag/AgCl, and exhibited a Faraday efficiency of 88.05% at -1.4 V vs. Ag/AgCl. In addition, the cycling test demonstrated that the Mo/TiO-M electrode possessed a good stability. This work not only provides an attractive electrode material, but also offers new insights into the rational design of catalysts for NORR.
PubMed: 38930847
DOI: 10.3390/molecules29122782 -
Molecules (Basel, Switzerland) Jun 2024The formation of nitrogen-containing organic interstellar molecules is of great importance to reveal chemical processes and the origin of life on Earth. Benzonitrile...
The formation of nitrogen-containing organic interstellar molecules is of great importance to reveal chemical processes and the origin of life on Earth. Benzonitrile (BN) is one of the simplest nitrogen-containing aromatic molecules in the interstellar medium (ISM) that has been detected in recent years. Methanol (CHOH) exists widely in interstellar space with high reactivity. Herein, we measured the infrared (IR) spectra of neutral and cationic BN-CHOH clusters by vacuum ultraviolet (VUV) photoionization combined with time-of-flight mass spectrometry. Combining IR spectra with the density functional theory calculations, we reveal that the BN-CHOH intends to form a cyclic H-bonded structure in neutral clusters. However, after the ionization of BN-CHOH clusters, proton-shared N···H···O and N···H···C structures are confirmed to form between BN and CHOH, with the minor coexistence of H-bond and O-π structures. The formation of the proton-shared structure expands our knowledge of the evolution of the life-related nitrogen-containing molecules in the universe and provides a possible pathway to the further study of biorelevant aromatic organic macromolecules.
PubMed: 38930810
DOI: 10.3390/molecules29122744 -
Micromachines May 2024Recently, various kinds of micro- and nanofluidic functional devices have been proposed, where a large surface-to-volume ratio often plays an important role in nanoscale...
Recently, various kinds of micro- and nanofluidic functional devices have been proposed, where a large surface-to-volume ratio often plays an important role in nanoscale ion transport phenomena. Ionic current analysis methods for ions, molecules, nanoparticles, and biological cells have attracted significant attention. In this study, focusing on ionic current rectification (ICR) caused by the separation of cation and anion transport in nanochannels, we successfully induce electrodiffusioosmosis with concentration differences between protons separated by nanochannels. The proton concentration in sample solutions is quantitatively evaluated in the range from pH 1.68 to 10.01 with a slope of 243 mV/pH at a galvanostatic current of 3 nA. Herein, three types of micro- and nanochannels are proposed to improve the stability and measurement accuracy of the current-voltage characteristics, and the ICR effects on pH analysis are evaluated. It is found that a nanochannel filled with polyethylene glycol exhibits increased impedance and an improved ICR ratio. The present principle is expected to be applicable to various types of ions.
PubMed: 38930669
DOI: 10.3390/mi15060698