Aspartate Research Articles

Nutritional and Functional Characteristics of Senescent Plantain Powder Mix

Post-harvest loss of plantain peeks at senescence. Drying senescent plantain enhances its culinary applications. This study aimed to determine the biochemical and functional properties of foam-mat dried senescent plantain samples, and their respective powdered mixes prepared for baking ofam (an Indigenous spicy cake). The nutritional benefits of foam-mat dried senescent plantain, with its high vitamin C and total carotenoid content, make it a valuable addition to dietary interventions. Foam-mat dried plantain samples and their respective powdered mixes were evaluated for their proximate composition, vitamin C, total carotenoids, amino acid contents, water and oil absorption capacities, and least gelation concentration using standard methods. The products were predominantly carbohydrates (73.3g - 80.4g/100g) with low moisture contents (9.19 - 20.68 g/100g). Vitamin C and total carotenoids ranged from 17.42 mg/100g to 33.99 mg/100g and 3.4 to 7.2 µg/g respectively. The samples had appreciable amounts of calcium (78.90 - 175.18 mg/100g), magnesium (112.13 - 113/79 mg/100g), potassium (95.76 - 77.09 mg/100g), iron (17.65 - 12.76 mg/100g) and zinc (10.94 - 15.82 mg/100 g). The most abundant amino acids were phenylalanine, histidine, methionine and aspartic acid. Sample SPPFSCF exhibited the best gelation capacity (22 g/100 mL). The water absorption capacities of the samples were influenced by the flour type used. However, the variations in the oil absorption capacities of the powdered mixes were statistically insignificant. EAPFRCF absorbed the least oil (0.84 g/g) while SPPFSCF absorbed the most (0.94 g/g). Foam-mat dried senescent plantain and their powdered mixes have the potential for utilization in nutritional interventions. Its low moisture content will support a longer shelf-life than the fresh overripe plantain.

Comparative analysis of the physical and chemical properties of dried products "KalmaKS" from the skin of the Commander and Pacific squid

The modern system of high-quality nutrition for the population includes the use of natural compounds from secondary products of animal origin. In the course of scientific substantiation of using secondary products from the processing of cephalopods, dried products from the skin of Pacific (Todarodes pacificus) and Commander squid (Berryteuthis magister) have been studied, their protein and amino acid composition and functional and technological characteristics have been analyzed. In samples from the skin of the Pacific squid, a high content of glutamic and aspartic acids (8–10 %) is noted; in samples from the skin of the Commander squid – glycine (20 %), proline (10 %) and arginine. High indicators of solubility, water-holding capacity and stability of foam structures are due to the significant content of type I destructured collagen (in a sample from the skin of Commander squid), and hydrophilic amino acids and type III collagen fragments (in a product made from Pacific squid skin). Infrared drying of products promotes denaturation and gelatinization of collagen in the skin of Commander squid, which is confirmed by the brighter color characteristics of the samples and high moisture-binding capacity when the temperature rises to 40 and 60 °C; this fact indicates an increase in the hydrophilic properties of the products of destruction of collagen fractions. Products made from skin, which is a secondary product of squid processing, have high potential for use in the food industry as water-retaining, fat-binding, and fat-emulsifying components.

New Supramolecular Hydrogels Based on Diastereomeric Dehydrotripeptide Mixtures for Potential Drug Delivery Applications.

Self-assembly of peptide building blocks offers unique opportunities for bottom-up preparation of exquisite nanostructures, nanoarchitectures, and nanostructured bulk materials, namely hydrogels. In this work we describe the synthesis, characterization, gelation, and rheological properties of new dehydrotripeptides, Cbz-L-Lys(Cbz)-L,D-Asp-∆Phe-OH and (2-Naph)-L-Lys(2-Naph)-L,D-Asp-∆Phe-OH, containing a N-terminal lysine residue Nα,ε-bis-capped with carboxybenzyl (Cbz) and 2-Naphthylacetyl (2-Naph) aromatic moieties, an aspartic acid residue (Asp), and a C-terminal dehydrophenylalanine (∆Phe) residue. The dehydrotripeptides were obtained as diastereomeric mixtures (L,L,Z and L,D,Z), presumably via aspartimide chemistry. The dehydrotripeptides afforded hydrogels at exceedingly low concentrations (0.1 and 0.04 wt%). The hydrogels revealed exceptional elasticity (G' = 5.44 × 104 and 3.43 × 106 Pa) and self-healing properties. STEM studies showed that the diastereomers of the Cbz-capped peptide undergo co-assembly, generating a fibrillar 3D network, while the diastereomers of the 2-Naph-capped dehydropeptide seem to undergo self-sorting, originating a fibril network with embedded spheroidal nanostructures. The 2-Naph-capped hydrogel displayed full fast recovery following breakup by a mechanical stimulus. Spheroidal nanostructures are absent in the recovered hydrogel, as seen by STEM, suggesting that the mechanical stimulus triggers rearrangement of the spheroidal nanostructures into fibers. Overall, this study demonstrates that diastereomeric mixtures of peptides can be efficacious gelators. Importantly, these results suggest that the structure (size, aromaticity) of the capping group can have a directing effect on the self-assembly (co-assembly vs. self-sorting) of diastereomers. The cytotoxicity of the newly synthesized gelators was evaluated using human keratinocytes (HaCaT cell line). The results indicated that the two gelators exhibited some cytotoxicity, having a small impact on cell viability. In sustained release experiments, the influence of the charge on model drug compounds was assessed in relation to their release rate from the hydrogel matrix. The hydrogels demonstrated sustained release for methyl orange (anionic), while methylene blue (cationic) was retained within the network.

Multi-omics profiling the dynamic variations of flavor and nutritional components during pearl gentian grouper soup processing

Flavor and nutritional value are essential components of fish soup, as highlighted by both producers and consumers. This study systematically examined the color, aroma, taste, and nutritional composition of pearl gentian grouper soup (PGGS) samples processed over varying durations, employing multi-omics technologies, including sensomics, volatilomics, lipidomics, and metabolomics. A comprehensive identification of 58 volatile aroma compounds, 407 lipids, 203 metabolites, and 47 taste components was achieved. The findings indicated that as processing time increased, the brightness of PGGS diminished, resulting in a thicker consistency. The aroma profile of PGGS was predominantly characterized by meaty and fatty notes, which were closely associated with carbonyl compounds (nonanal, dodecanal, (E)-2-octenal, and 2-undecanone) that developed due to glyceride oxidation during prolonged thermal processing. The predominant taste profile of PGGS was identified as umami, likely resulting from the synergistic effects of umami-enhancing amino acids (glutamic acid, aspartic acid) and 5ʹ-nucleotides (adenosine monophosphate, inosine monophosphate, guanosine monophosphate). Furthermore, PGGS may represent a significant source of taurine, with its taurine content accounting for over 60% of the total free amino acids (FAAs). Considering the variations in color, flavor, and nutritional content throughout the processing of PGGS, as well as the associated time costs, a processing duration of 2 h was optimal.

RGD-functionalised self-assembling peptide hydrogel induces a proliferative profile in human osteoblasts in vitro.

Self-assembling peptide hydrogels (SAPHs) have been used in the past decade as reliable three-dimensional (3D) synthetic scaffolds for the culture of a variety of mammalian cells in vitro. Thanks to their versatile physicochemical properties, they allow researchers to tailor the hydrogel properties, including stiffness and functionality to the targeted cells and cells' behaviour. One of the advantages of using SAPH scaffolds is the ease of functionalisation. In the present work, we discuss the effect that functionalising the FEFEFKFK (F, phenylalanine; K, lysine; and E, glutamic acid) hydrogel scaffold using the cell-binding RGDS (fibronectin - R, arginine; G, glycine; D, aspartic acid; S, serine) epitope affects the material properties as well as the function of encapsulated human osteoblast cells. RGDS functionalisation resulted in cells adopting an elongated morphology, suggesting attachment and increased proliferation. While this led to higher cell viability, it also resulted in a decrease in extra-cellular matrix (ECM) protein production as well as a decrease in calcium ion deposition, suggesting lower mineralisation capabilities. The work clearly shows that SAPHs are a flexible platform that allow the modification of scaffolds in a controlled manner to investigate cell-material interactions.

Dual synergistic function of pyrite modified biochar synthesized with chelating agent for mediating arsenic removal process: Reactive site identification and pathway mechanism exploration

Arsenic (As) contamination is widespread around the world, particularly the As(III) with highly toxic and carcinogenic posing huge threats to the biosphere. The secondary pollution and high energy consumption caused by the current method prompt the need for economically feasible and sustainable scheme to achieve As removal. In this study, the pyrite (FeS2) modified biochar (IP-BC) was synthesized with assistance of N-(1,2-dicarboxyethyl)-D, L-aspartic acid (IDHA) achieving uniform distribution of Fe components and S configuration on biochar surface. These improved characteristics enable IP-BC to have excellent catalytic and adsorption capacity in coupled peroxydisulfate (PDS) system with 11.3- and 11.8- times higher removal efficiency of total As than pristine biochar and FeS2, respectively. The reactive oxidizing substances dominated by •OH are responsible for As(III) oxidation, which could be produced by IP-BC regarding the structural Fe(Ⅱ), phenolic hydroxyl and carboxyl group as possible reactive sites. S22−, Sn2− and hydroxyl of IP-BC could act as electron donors involving in Fe(II)/Fe(III) cycle, promoting the oxidation of As(III) to As(V). The final immobilization mechanism of arsenic by IP-BC was dominated by hydrogen bonding in individual system, while it transformed into the complexation and co-precipitation related with structural Fe of IP-BC in PDS coupled system. Results confirmed the prominent performance of IP-BC/PDS system that total As concentration decreased to < 10 µg/L (maximum contaminant limit) within 60 min in different water matrix. Therefore, this work provides potential insights to guide the synthesis of functional and green biochar converting from solid wastes of mining and forestry to reach the goal of efficient arsenic removal.

Effects of L-Proline on the Stability of Mulberry Anthocyanins and the Mechanism of Interaction between L-Proline and Cyanidin-3-O-Glycoside.

The protective effects of L-aspartic acid, L-valine, and L-proline on the stability of mulberry anthocyanins were investigated. Results showed that L-aspartic acid, L-valine, and L-proline significantly enhanced (p < 0.05) the stability of mulberry anthocyanins under constant light or ascorbic acid (AA). L-Proline had the best protective effect against anthocyanin degradation. The interaction between L-proline and cyanidin-3-O-glucoside (C3G) through hydrogen bonding and van der Waals forces, which improved the stability of C3G, was confirmed using FT-IR, 1H NMR, XRD, and molecular docking analyses, as well as molecular dynamics modes. In vitro digestion experiments yielded that both 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radical scavenging capacities of the C3G/Pro group were increased in the intestinal fluid (p < 0.05). The above findings suggest that L-proline effectively slowed down the degradation of mulberry anthocyanins, and that it could be used as an auxiliary pigment and food additive to extend the optimal flavor period of products containing mulberry anthocyanins, and can improve the bioavailability of mulberry anthocyanins.

Comparative Study on Growth and Metabolomic Profiles of Six Lactobacilli Strains by Sodium Selenite

Selenium (Se) has garnered increasing attention in the field of nutrition, as it is essential for both humans and animals. Certain microorganisms can enrich inorganic selenium and convert it into organic selenium. The growth and metabolomic profiles of six lactobacilli strains exposed to 50 μg/mL of sodium selenite were performed using gas chromatography tandem time-off light mass spectrometry (GC-TOF-MS) analysis. The addition of selenium significantly increased both the population and weight of the Lacticaseibacillus rhamnosus PS5, Lbs. rhamnosus RT-B, Limosilactobacillus reuteri 3630, and Lmb. reuteri 1663 strains, while those of the other two strains decreased. A total of 271 metabolites were determined, with their concentrations ranked from highest to lowest as follows: organic acids and derivatives, oxygen compounds, lipids and lipid-like molecules, and benzenoids. In certain groups, the concentrations of serine, aspartic acid, trehalose, palmitic acid, methylthreonine, and melibiose increased significantly, whereas glucuronic acid, ribose, ornithine, and methionine were downregulated. The metabolic pathways were significantly associated with ABC transporters, glycine, serine, threonine metabolism, and aminobenzoate degradation and other pathways. Based on these findings, we concluded that the transport, absorption, assimilation, and stress response to selenium by lactobacilli in metabolomic changed. Furthermore, the metabolomic alterations among different types of lactobacilli varied primarily due to their distinct properties.

Candidatus Thiothrix phosphatis SCUT-1: A novel polyphosphate-accumulating organism abundant in the enhanced biological phosphorus removal system

A novel coccus Thiothrix-related polyphosphate-accumulating organism (PAO) was enriched in an acetate-fed enhanced biological phosphorus removal (EBPR) system. High EBPR performance was achieved for an extended period (>100 days). A high-quality draft genome (completeness 97.2 %, contamination 3.26 %) was retrieved, representing a novel Thiothrix species (with similarity<93.2 % to known Thiothrix species), and was denoted as 'Candidatus Thiothrix phosphatis SCUT-1'. Its acetate uptake rate (6.20 mmol C/g VSS/h) surpassed most Ca. Accumulibacter and known glycogen-accumulating organisms (GAOs), conferring their predominance in the acetate-fed system. Metatranscriptomic analysis suggested that Ca. Thiothrix phosphatis SCUT-1 employed both low- and high-affinity pathways for acetate activation, and both the conventional (PhaABC) pathway and the fatty acid β-oxidation pathway for PHA synthesis; additionally, a much more efficient FAD-dependent malate: quinone oxidoreductase (MQO) were encoded and employed than the traditional malate dehydrogenase (MDH) to oxidize malate to oxaloacetate in the TCA and glyoxylate cycle, collectively contributing to a higher acetate utilization and processing rate of this microorganism. Batch tests further demonstrated the versatile ability of this PAO in using VFA (acetate, propionate, and butyrate), lactate, amino acids (aspartate and glutamate), and glucose as carbon sources for EBPR, showing a partially overlapped but unique ecological niche of this microorganism comparing to Ca. Accumulibacter and known GAOs. A metabolic model was built for Ca. Thiothrix phosphatis SCUT-1 using the above-mentioned carbon sources for EBPR. Overall, this study represents the first comprehensive characterization of the physiology and metabolic characteristics of representative coccus Thiothrix-related PAOs, which are expected to provide new insights into PAO microbiology in EBPR systems.

Targeting harmful effects of non-excitatory amino acids as an alternative therapeutic strategy to reduce ischemic damage.

The involvement of the excitatory amino acids glutamate and aspartate in cerebral ischemia and excitotoxicity is well-documented. Nevertheless, the role of non-excitatory amino acids in brain damage following a stroke or brain trauma remains largely understudied. The release of amino acids by necrotic cells in the ischemic core may contribute to the expansion of the penumbra. Our findings indicated that the reversible loss of field excitatory postsynaptic potentials caused by transient hypoxia became irreversible when exposed to a mixture of just four non-excitatory amino acids (L-alanine, glycine, L-glutamine, and L-serine) at their plasma concentrations. These amino acids induce swelling in the somas of neurons and astrocytes during hypoxia, along with permanent dendritic damage mediated by N-methyl-D-aspartate receptors. Blocking N-methyl-D-aspartate receptors prevented neuronal damage in the presence of these amino acids during hypoxia. It is likely that astroglial swelling caused by the accumulation of these amino acids via the alanine-serine-cysteine transporter 2 exchanger and system N transporters activates volume-regulated anion channels, leading to the release of excitotoxins and subsequent neuronal damage through N-methyl-D-aspartate receptor activation. Thus, previously unrecognized mechanisms involving non-excitatory amino acids may contribute to the progression and expansion of brain injury in neurological emergencies such as stroke and traumatic brain injury. Understanding these pathways could highlight new therapeutic targets to mitigate brain injury.

Identification of a thermostable L-asparaginase from Pyrococcus yayanosii CH1 and its application in the reduction of acrylamide.

L-asparaginase (ASNase, E.C. 3.5.1.1) catalyzes the deamination of L-asparagine to L-aspartic acid and ammonia and is widely used in medicine to treat acute lymphocytic leukemia. It also has significant applications in the food industry by inhibiting acrylamide formation. In this study, we characterized a thermostable ASNase from the hyper thermophilic strain, Pyrococcus yayanosii CH1. The recombinant enzyme (PyASNase) exhibited maximal activity at pH 8.0 and 85°C. Moreover, PyASNase demonstrated promising thermostability across temperatures ranging from 70 to 95°C. The kinetic parameters of PyASNase for L-asparagine were a Km of 6.3mM, a kcat of 1989s-1, and a kcat/Km of 315.7mM-1s-1. Treating potato samples with 10 U/mL of PyASNase at 85°C for merely 10min reduced the acrylamide content in the final product by 82.5%, demonstrating a high efficiency and significant advantage of PyASNase in acrylamide inhibition.

Growth and physiological metabolic regulation mechanisms of the dominant plant Leymus secalinus in alpine meadow under nitrogen deposition

Nitrogen (N) deposition is an important pathway that affects the growth and development of alpine grassland plants. Under N deposition, Leymus secalinus has become the most dominant species in the alpine meadow of the Qinghai-Tibetan Plateau. However, its adaptive mechanisms to N deposition are still unknown. Therefore, we analyzed the physiological indices of Leymus secalinus under different N deposition levels (CK, 0 kg N ha−1 yr−1; N1, 8 kg N ha−1 yr−1; N3, 40 kg N ha−1 yr−1; N5, 72 kg N ha−1 yr−1) and focused on its growth and metabolism. The results indicated that the leaf carbon (C), N, amino acid (AA), and photosynthetic pigment contents in Leymus secalinus were significantly increased under N deposition, its endogenous hormone levels were regulated and the activities of N metabolism-related enzymes were enhanced. Metabolomics analysis further showed that the metabolites changed significantly and were mostly enriched in the amino acid metabolic pathway. Among them, glutamine and aspartic acid played key roles in N deposition for dominant growth of Leymus secalinus by regulating N and amino acid metabolism. These analyses unveiled the physiological and biochemical changes of dominant species in response to N deposition, identifying critical metabolites involved in this process. Furthermore, these findings provide substantial evidence explaining the ecological phenomenon of Leymus secalinus emerging as a dominant species under N deposition, serving as a data reference for understanding the physiological response and adaptation to N deposition in alpine grassland plants.

Assessment of amino acid charge states based on cryo-electron microscopy and molecular dynamics simulations of respiratory complex I

The charge states of titratable amino acid residues play a key role in the function of membrane-bound bioenergetic proteins. However, determination of these charge states both through experimental and computational approaches is extremely challenging. Cryo-EM density maps can provide insights on the charge states of titratable amino acid residues. By performing classical atomistic molecular dynamics simulations on the high resolution cryo-EM structures of respiratory complex I from Yarrowia lipolytica, we analyze the conformational and charge states of a key acidic residue in its ND1 subunit, aspartic acid D203, which is also a mitochondrial disease mutation locus. We suggest that in the native state of respiratory complex I, D203 is negatively charged and maintains a stable hydrogen bond to a conserved arginine residue. Alternatively, upon conformational change in the turnover state of the enzyme, its sidechain attains a charge-neutral status. We discuss the implications of this analysis on the molecular mechanism of respiratory complex I.

Physiology, Pathophysiology and Clinical Relevance of D-Amino Acids Dynamics: From Neurochemistry to Pharmacotherapy.

Over three decades ago, two independent groups of investigators identified free D-aspartic and later D-serine in specific brain nuclei and endocrine glands. This finding revealed a novel, non-proteinogenic role of these molecules. Moreover, the finding that aged proteins from the human eye crystallin, teeth, bone, blood vessels or the brain incorporate D-aspartic acids to specific primary protein sequences fostered the hypothesis that aging might be related to D-amino acid isomerization of body proteins. The experimental confirmation that schizophrenia and neurodegenerative diseases modify plasma free D-amino acids or tissue levelsnurtured the opportunity of using D-amino acids as therapeutic agents for several disease treatments, a strategy that prompted the successful current application of D-amino acids to human medicine.

Synthesis and Mechanism of a Green Scale and Corrosion Inhibitor.

A new green water treatment agent, a poly(aspartic acid)-modified polymer (PASP/5-AVA), was synthesized using polysuccinimide and 5-aminovaleric acid (5-AVA) in a hybrid system. The structure was characterized, and the scale and corrosion inhibition performance were carried out with standard static scale inhibition and electrochemical methods, respectively. The mechanism was explored using XRD, XPS, SEM, and quantum chemistry calculations. The results indicated that PASP/5-AVA exhibited better scale and corrosion inhibition performance than PASP and maintained efficacy and thermal stability of the scale inhibition effect for a long time. Mechanistic studies indicated that PASP/5-AVA interferes with the normal generation of CaCO3 and CaSO4 scales through lattice distortion and dispersion, respectively; the combined effect of an alkaline environment and terminal electron-withdrawing -COOH groups can induce the stable C- ionic state formation in -CH2- of the extended side chain, thus enhancing its chelating ability for Ca2+ ions. At the same time, the extension of the side chain length also enhances the adsorption ability of the agent on the metal surface, forming a thick film and delaying the corrosion of the metal surface. This study provides the necessary theoretical reference for the design of green scale and corrosion agents.

Comparative study on metabolites, nutrients, and antioxidant capacity of endosperm in Gymnocladus chinensis, Gleditsia sinensis, and Gleditsia japonica var. delavayi

‘Zaojiaomi’ is a traditional food derived from Gleditsia sinensis or Gleditsia japonica var. delavayi endosperm. However, metabolite profile of Gymnocladus chinensis endosperm and its comparison to the aforementioned species remains understudied. This research employed a UPLC-MS based metabolomics approach to investigate and compare metabolite composition of G. chinensis endosperm with that of G. sinensis and G. japonica endosperm. A total of 1177 metabolites were identified, with 579 and 577 differentially abundant metabolites found between G. chinensis vs. G. japonica and G. chinensis vs. G. sinensis, respectively. They were mainly enriched in pathways related to flavonoid biosynthesis, suggesting potential for enhanced antioxidant activity, compared to G. japonica and G. sinensis. Additionally, G. chinensis endosperm was found to be rich in L-arginine, L-aspartic acid, and zinc elements, which have various health benefits. These findings provide valuable insights into metabolic composition of G. chinensis endosperm and its potential as a functional food source.

Evaluation of Fasting Bile Acid Levels in Pregnant Women Diagnosed with Hyperemesis Gravidarum

Background: Hyperemesis gravidarum is a common cause of nausea and vomiting during the early gestational week. At the same time, it can also lead to an increase in liver enzyme values in patients due to or independently of underlying liver disease. This study aimed to evaluate fasting bile acid (FBA) levels, alanine aminotransferase (ALT), aspartate aminotransferase (AST), total and direct bilirubin, and urine ketone levels in pregnant women diagnosed with hyperemesis gravidarum (HG). Additionally, the study sought to investigate the relationship between HG and FBA levels. The diagnosis of HG remains primarily clinical, and identifying markers for disease severity is crucial. Methods: This retrospective cohort study obtained blood samples from 50 women diagnosed with HG and 25 healthy pregnant women. Serum levels of AST, ALT, total bilirubin (TBS), direct bilirubin, urine ketones, and FBA were measured. Statistical analysis was performed using the SPSS software version 28.0. Results: FBA levels were significantly higher in pregnant women diagnosed with HG compared to the healthy control group. Additionally, FBA levels increased simultaneously with ketonuria in the patient group. Our findings suggest that FBA levels can serve as a biomarker for diagnosing HG and indicating early-stage liver damage. Unlike previous studies, our research focused on the relationship between FBA levels and HG, providing valuable insights for future studies. Conclusions: FBA levels show promise as an objective biomarker for diagnosing HG and indicating early-stage liver damage. Further research with larger cohorts is necessary to validate these findings.

Spatial distribution of dissolved free amino acids in three Iberian Atlantic estuaries

Rivers and estuaries are the main link between land and ocean, transferring significant amounts of dissolved organic carbon. These ecosystems receive large amount of dissolved organic matter (DOM) from diverse sources, both allochthonous and autochthonous. Within this pool, dissolved free amino acids (DFAA) represent the most labile fraction, offering valuable insights into DOM composition and diagenetic processes. Our study focused on three Iberian Atlantic estuaries—Guadalquivir, Guadiana, and Tinto-Odiel— that differ in hydrology, land use and DOM sources. We studied the longitudinal distribution of DFAA and their response to tidal cycles across these estuaries. Despite similar DFAA concentrations between estuaries (176.6 nM to 1770 nM) were found, variations in specific amino acids like glutamic acid, taurine, and aspartic acid pointed to a substantial influence of terrestrial inputs in Guadalquivir and Guadiana estuaries and an anthropogenic influence in Tinto-Odiel. Predominant amino acids—serine, glycine, ornithine, and asparagine —comprised more than 50 mol% of the estuarine DFAA pool. The dominance of serine, glycine, and ornithine indicated substantial DOM degradation, possibly associated with the loss of labile DOM during estuarine transport. Concurrently, asparagine prevalence was linked to allochthonous DOM input particularly associated with terrestrial runoff, lateral input, and anthropogenic activities at estuarine margins. Our results underscore the impact of tidal cycles on DFAA distribution and emphasize the potential of DFAA in unraveling estuarine DOM dynamics and their role as indicators of reactivity and composition in estuarine biogeochemistry.

A synonymous mutation of rs1137070 cause the mice Maoa gene transcription and translation to decrease.

The Monoamine Oxidase-A (MAOA) EcoRV polymorphism (rs1137070) is a unique synonymous mutation (c.1409 T > C) within the MAOA gene, which plays a crucial role in Maoa gene expression and function. This study aimed to explore the relationship between the mouse Maoa rs1137070 genotype and differences in MAOA gene expression. Mice carrying the CC genotype of rs1137070 exhibited a significantly lower Maoa expression level, with an odds ratio of 2.44 compared to the T carriers. Moreover, the wild-type TT genotype of MAOA demonstrated elevated mRNA expression and a longer half-life. We also delved into the significant expression and structural disparities among genotypes. Furthermore, it was evident that different aspartic acid synonymous codons within Maoa influenced both MAOA expression and enzyme activity, highlighting the association between rs1137070 and MAOA. To substantiate these findings, a dual-luciferase reporter assay confirmed that GAC was more efficient than GAT binding. Conversely, the synonymous mutation altered Maoa gene expression in individual mice. An RNA pull-down assay suggested that this alteration could impact the interaction with RNA-binding proteins. In summary, our results illustrate that synonymous mutations can indeed regulate the downregulation of gene expression, leading to changes in MAOA function and their potential association with neurological-related diseases.

Renaissance of Ketamine

The history of ketamine began in the 1960s. Ketamine is a specific anesthetic drug that exhibits analgesia, has a stabilizing impact on the cardiovascular system and does not significantly depress the respiratory system. It is responsible for causing the so-called dissociative effect. The effects of ketamine depend on the dose. Its mechanism of action is based primarily on the blockade of N-methyl D-aspartic acid receptors (NMDA) in the central nervous system. Due to its favorable action profile and small number of contraindications, ketamine is becoming an increasingly popular drug. In medicine, it is commonly used as an analgesic and an anesthetic. Studies conducted over recent years have noted that it can be effective in conditions such as: status epilepticus, status asthmaticus, agitation, alcohol dependence and alcohol withdrawal syndrome, depression, and suicidal thoughts. This paper reviews current reports on the uses of ketamine, beneficial especially to physicians with the Specialty in emergency medicine.