Search Results (103)

Heavy metal pollution from mining activities and urban runoff poses a serious threat to public health and aquatic ecosystems in vulnerable communities around the Bolivia–Peru transboundary Lake Titicaca basin. This study evaluates the use of two abundant wetland plants—totora (Schoenoplectus californicus) and reed (Phragmites australis)—as low-cost, locally available biosorbents for the removal of dissolved iron (Fe²⁺) from the Pallina River, a major contaminant source to Cohana Bay. Monitoring data from Bolivia’s Ministry of Environment and Water (2019–2022) revealed Fe²⁺ concentrations exceeding the national legal limit (0.3 mg/L) by more than 20 times during the dry season. Laboratory experiments using synthetic Fe²⁺ solutions (20 mg/L) optimized biosorption conditions, identifying pH 5, 4–6 g/L biomass, fine particle size (0.15–0.212 mm), and a 3 h contact time as optimal. Both plants followed pseudo-second-order kinetics and Langmuir isotherms. Totora showed superior performance, achieving a maximum capacity of 7.8 mg/g compared to reed’s 2.9 mg/g. Continuous-flow column tests removed up to 95% of Fe²⁺ from synthetic water. When applied to real Pallina River water, totora achieved 50% Fe²⁺ removal despite reduced efficiency due to competing organic matter. The findings demonstrate the potential of totora-based biosorption as a scalable, nature-based solution for transboundary water management. The policy implications of this study are profound under the national and global water and wetland governance mechanisms and transboundary frameworks like the Binational Autonomous Authority of Lake Titicaca (ALT, est. 1996) and Ramsar Convention. Full article

This study presents the first comprehensive soil gas survey across southern Uruguay’s H₂ prospective terranes. A pre-field trip selection was done on the basement rock nature, as well as vegetation anomalies in subcircular depressions and fault presence. The Neoproterozoic terrane, north of Punta del Este, and the Archean Rio de la Plata Craton, north of Montevideo, as well as along the suture zones between the two, were targeted. Our findings reveal substantial H₂ concentrations, significantly outperforming many established basins worldwide. The suture zones act as critical migration conduits for H₂ coming from a deeper structural level. Slightly abnormal helium signatures confirm an active, deep-sourced fluid system, particularly within the Sierra Ballena and Cordillera shear zones. The Archean Rio de la Plata Craton appears promising but has only been partially sampled and warrants further investigation. These results underscore the high potential of Uruguay as a new frontier for natural hydrogen exploration. Full article

Cardamom (Elettaria cardamomum (L.) Maton) is a major export crop in Guatemala; however, its genetic basis remains largely unexplored. This study aimed to evaluate the genetic diversity and differentiation among 288 cardamom accessions from the Northern Transversal Strip, the country’s primary production area. Eleven molecular markers (SSR, ISSR, and EST-SSR) were used to generate multilocus profiles analyzed under a dominant model. Genetic diversity revealed average values of Shannon’s index (I = 0.316) and expected diversity (h = 0.207), with SSR markers providing the highest values (I = 0.364, h = 0.233). Bayesian and hierarchical analysis identified three genetic groups (K = 3). The relatively low diversity observed is consistent with the introduction history of this crop in Guatemala, human-driven selection, and historical bottlenecks caused by Cardamom Mosaic Virus and thrips infestations. Despite these constraints, private and high-frequency bands were detected across genetic groups, offering potential for marker-assisted selection. These findings provide the first genetic baseline for Guatemalan cardamom, supporting future breeding strategies aimed at improving resilience, productivity, and adaptation to climate change. Full article

Esterases catalyze the hydrolysis and transesterification of short-chain fatty acid esters, and microbial esterases are used in the production of biofuels, cosmetics, food, and pharmaceuticals. The soil strain Bacillus paralicheniformis T7 secretes enzymes with esterase activity; however, many bacterial enzymes remain insufficiently studied. Therefore, this study aimed to identify and characterize novel GDSL esterases produced by B. paralicheniformis. Protein mass spectrometry, combined with proteomics and genomics, identified genes encoding two GDSL esterases, which were cloned into the pET-28c(+) vector. The resulting proteins were obtained in Escherichia coli BL21(DE3) as the recombinant esterases rEST-24 and rEST-28. These recombinant GDSL esterases showed maximum activity at 40 °C and pH 7.0. Moreover, Ca²⁺, Zn²⁺, Cu²⁺, and Fe²⁺ ions inhibited their activity, and rEST-28 was resistant to the detergents Tween-20, Tween-80, and Triton X-100. High-yield esterase activity was detected in bacteria cultured on feather medium and nutrient broth, and submerged fermentation of the B. paralicheniformis T7 strain on feather medium enabled the production of an esterase extract exhibiting activity of 17,618 ± 610 U/g. These results suggest that the B. paralicheniformis T7 strain can produce esterases and shows promising potential for application in technologies that degrade fatty acid esters using hydrolytic enzymes. Full article

The thermophilic bacterium Thermus thermophilus represents a crucial genetic reservoir for exploring thermostable enzymes as valuable biocatalysts for industrial and biotechnology applications. Here, we identify, clone, and characterize Ces1-ET, Est1-ET, and Plp1-ET, three lipolytic enzymes obtained from T. thermophilus strain ET-1 isolated from El Tatio Geothermal Field in Northern Chile. To enable recombinant expression, we constructed the pTGT-1 expression system, a versatile bifunctional shuttle vector compatible with both Escherichia coli and T. thermophilus. The three thermoenzymes Ces1-ET, Est1-ET, and Plp1-ET, were successfully cloned, expressed, and purified using the pTGT-1 system, with a molecular mass of 25 kDa, 36 kDa, and 28 kDa, respectively. The recombinant purified enzymes displayed optimal temperatures at 60 °C, 80 °C, and 70 °C and optimal pH of 7.5, 9.0, and 8.0 for Ces1-ET, Est1-ET, and Plp1-ET, respectively. Functional biochemical assays revealed a broad tolerance to surfactants, detergents, divalent cations, and high salinity, relevant properties for their application in an industrial setting. These thermostable esterases expand the repertoire of thermozymes from Thermus spp., introducing pTGT-1 as an innovative tool for thermophilic protein expression and highlighting T. thermophilus strain ET-1 from El Tatio Geothermal Field as a valuable source of thermostable enzymes for industrial and biotechnology applications. Full article

Background/Objectives: The global prevalence and incidence of inflammatory bowel diseases have risen in the past two decades. Among them, Crohn’s disease and ulcerative colitis are still challenging to treat due to vascular and proliferative alterations. Studies in rats suggest that blocking histamine receptors (H1–H4) can improve colitis progression. However, the specific histamine receptor responsible for this effect remains debated. The experiment aimed to assess the role of specific histamine receptor subtypes in colitis development, focusing on oxidative stress markers in the liver and skeletal muscle. Methods: The study involved 60 adult male Wistar rats, divided into control and colitis experimental groups. Colitis was induced through intracolonic administration of 2,4,6-trinitrobenzenesulfonic acid. Animals in both experimental groups received intramuscular injections of NaCl (non-treated, NT) or H1, H2, H3, and H4 receptor antagonists (10 study subgroups in total). On day eight, the animals were re-anesthetized and euthanized via exsanguination. Then, liver and skeletal muscle (m. soleus) samples were collected for analysis of oxidative stress markers. Results: The analyses of skeletal muscle samples showed that using the H1 and H2 receptor antagonists increased superoxide dismutase (SOD) and catalase (CAT) activities, as well as parameters related to glutathione metabolism (reduced glutathione (GSH), glutathione S-transferase (GST)) in rats from the control groups, indicating enhanced antioxidant defense. In rats with chemically induced colitis, we observed that H1 receptor antagonists elevated CAT activity, whereas β-esterase (β-EST) activity remained elevated across all colitis subgroups. In the liver, histamine receptor antagonists produced receptor-specific redox effects: the H2 receptor antagonist reduced oxidative damage (malondialdehyde (MDA)); the H1 receptor antagonist attenuated SOD hyperactivity, but depleted GSH; and the H4 receptor antagonist increased GSH while elevating MDA. Chemically induced colitis increased α- and β-EST activities, whereas administration of the H1 or H3 antagonist reduced β-EST levels. Conclusions: Histamine receptor antagonists modulated oxidative stress responses in both liver and skeletal muscle tissues in a receptor-dependent manner. Among them, the H2 receptor antagonist most effectively mitigated hepatic oxidative injury, highlighting its potential as a therapeutic target in colitis-associated systemic oxidative stress. Full article

Background: Device-detected subclinical atrial fibrillation (SCAF) and atrial high-rate episodes (AHRE) are increasingly recognized in patients with cardiac implantable electronic devices and through long-term rhythm monitoring. Although often asymptomatic, these episodes are associated with a higher risk of clinical atrial fibrillation (AF), stroke, and heart failure. Aims: This narrative review summarizes clinical, electrocardiographic, echocardiographic, and circulating biomarkers associated with the development and progression of device-detected SCAF/AHRE. Methods: We performed a comprehensive search of PubMed, Embase, and Scopus using combinations of the terms “subclinical atrial fibrillation”, “atrial high-rate episodes”, “device-detected AF”, “predictive factors”, “P-wave morphology”, “echocardiographic parameters”, “left atrial strain”, and “biological markers”. We included English-language-only studies of patients with cardiac implantable electronic devices or long-term monitoring and reporting incident SCAF/AHRE or AF as outcomes, published in the last 10 years. Results: Older age, high body mass index, heart failure, obstructive sleep apnea, and C₂HEST score are consistently associated with SCAF. On-surface electrocardiogram (ECG) and device electrograms, prolonged and dispersed P-wave indices, low atrial sensing amplitude, and specific pacing configurations, particularly right ventricular apical pacing with wide QRS, predict incident and longer-lasting AHRE. Echocardiographic markers of atrial cardiomyopathy, including increased left atrial volume and impaired atrial strain, together with indices of left ventricular diastolic dysfunction, further refine risk. Among circulating biomarkers, galectin-3 and high-sensitivity C-reactive protein show the most reproducible associations with incident AHRE. Conclusions: A multiparametric approach combining clinical profile, ECG features, advanced echocardiography, and selected biomarkers may improve identification of patients at risk for device-detected SCAF. Further prospective studies are needed to define risk thresholds that justify intensified rhythm surveillance and early initiation of anticoagulation or rhythm control strategies, especially in AHRE shorter than 24 h. Full article

This study investigates the atmospheric corrosion behavior of zinc in tropical marine environments affected by hydrogen sulfide (H₂S), particularly from the decomposition of stranded Sargassum algae. Four exposure sites in Martinique with varying levels of H₂S and marine chlorides were selected. Gravimetric analysis showed that zinc thickness loss reached up to 45 µm after one year at the most impacted site (Frégate Est), compared to only 3–10 µm at less contaminated locations. This degradation level classifies the site as “extremely corrosive” according to ISO 9223. Electrochemical impedance spectroscopy (EIS) and linear polarization measurements revealed distinct corrosion behaviors. After 12 months of exposure, the polarization resistance and corrosion current density reached R_p = 916 Ω·cm² and I_corr = 28 µA·cm² at the Frégate Est site and R_p = 1835 Ω·cm² and I_corr = 6 µA·cm² at the Vauclin site. In H₂S-poor environments (Diamant, Vert-Pré, Vauclin), corrosion resistance increased over time due to the formation of protective layers such as hydrozincite and simonkolleite. In contrast, H₂S-rich environments favored the formation of sulfur-based compounds like elemental sulfur and zinc sulfide (ZnS), which exhibit poor protective properties and result in lower polarization resistance and higher corrosion current densities. Polarization curves confirmed a general decrease in anodic and cathodic currents over time, with less significant improvements in passivation at H₂S-impacted sites. The corrosion mechanism is influenced by both pollutant type and exposure duration. Overall, this study highlights the synergistic effect of H₂S and chlorides on accelerating zinc corrosion and underscores the need for adapted protection strategies in tropical coastal zones affected by Sargassum proliferation. Full article

Helichrysum italicum (Roth) G. Don (Asteraceae) is a valuable medicinal and aromatic plant native to a variety of habitats across the Mediterranean region. However, genetic studies of this morphologically diverse species have been limited by the scarcity of species-specific DNA markers. To address this limitation, we generated the first de novo transcriptome assembly comprising 24,806 transcripts from young shoots containing leaves and flowers, developed EST-SSR markers, and evaluated their utility in population genetic analysis. Seventy-eight primer pairs were designed, of which 23 showed successful amplification, polymorphism, and transferability to Helichrysum litoreum Guss. and Helichrysum arenarium (L.) Moench. A subset of 12 EST-SSRs was used to genotype 270 individuals from 12 natural populations of H. italicum in Corsica (France), along with one outgroup population from Croatia. The polymorphic information content ranged from 0.250 to 0.796, and Shannon’s information index ranged from 0.588 to 1.843, indicating the markers’ suitability for population genetic studies. Analysis of molecular variance revealed that 15% of the total genetic variation was attributable to differences among populations. Discriminant analysis of principal components and Bayesian clustering in STRUCTURE identified distinct population clusters corresponding to geographic locations. Notably, the southernmost coastal populations were clearly differentiated from the others. Full article

Background/Objectives: Long-read metagenomic sequencing can detect bacteria and antimicrobial resistance genes (ARGs) from bovine respiratory samples, providing an alternative to culture and antimicrobial susceptibility testing (C/S). This study applied Bayesian latent class models (BLCMs) to estimate the sensitivity (Se) and specificity (Sp) of long-read metagenomic sequencing compared to C/S for detecting Mannheimia haemolytica, Pasteurella multocida, and Histophilus somni, as well as associated macrolide and tetracycline resistance potential. Methods: Deep nasopharyngeal swabs were collected from fall-placed feedlot calves at arrival, 13, and 36 days on feed across two years and two metaphylaxis protocols. Samples underwent C/S and long-read metagenomic sequencing. BLCMs were used to estimate Se and Sp for the detection of bacteria and potential for antimicrobial resistance (AMR). Results: Se and Sp for detecting respiratory bacteria by metagenomics were not significantly different than culture, with four exceptions. For the 2020 samples, Se for M. haemolytica was lower than culture, and Sp for H. somni was lower, while in both 2020 and 2021 samples, Se for P. multocida was higher for metagenomics than culture. The estimated Se and Sp of metagenomics for the detection of msrE-mphE, EstT, and tet(H) within bacterial reads were either not significantly different or were lower than AST, with Sp > 95% with one exception. Conclusions: This study provided BLCM-based estimates of clinical Se and Sp of metagenomics and C/S without assuming a gold standard in a large pen research setting. These findings demonstrate the potential of long-read metagenomics to support bovine respiratory disease diagnostics, AMR surveillance, and antimicrobial stewardship in feedlot cattle. Full article

Background/Objectives: Esterases are widely used in various industrial fields. This study aimed to isolate and characterize esterase genes from Laceyella sacchari HS49-1, a thermophilic bacterium from a hot spring, which can survive at 45–60 °C and pH 5-10 with robust esterase activity. Methods: A genomic shotgun library was constructed to identify three esterase genes: two in family XII (Est2 and Est7) and one in family VIII (Est1). Sequence analysis revealed significant divergence from other genera. Only Est1 was successfully expressed in Escherichia coli. Its activity, optimal conditions, thermostability, and structure were investigated using p-NP butyrate, temperature/pH assays, heating pre-treatment, and fluorescence quenching. Results: Est1 demonstrated high activity (57.43 ± 0.04 U/mg) towards short-chain p-NP butyrate (C4). Molecular-docking analyses revealed that Est1’s catalytic motif (GXSXG) interacts with various p-NP esters, with binding energy and interaction types varying by acyl chain length. The optimal temperature was 60 °C, and the optimal pH was 8. Est1 exhibited excellent thermostability, retaining 90% of its activity after pre-treatment at 50 °C for 8 h and 69.8% after pre-treatment at 80 °C for the same duration. Fluorescence quenching showed that after 1 h at 80 °C, the fluorescence was reduced by only 16.6%, indicating remarkable heat resistance. Additionally, Est1 did not require metal ions as cofactors and maintained 74.8% of its activity in the presence of 0.1% SDS. Conclusions: The unique properties of Est1 from L. sacchari HS49-1 highlight its potential for industrial applications. Further exploration of this thermophilic bacterium could uncover more valuable genes. Full article

Background/Objectives: Long-read metagenomic sequencing can assign antimicrobial resistance genes (ARGs) to speciated bacterial reads. This study evaluated whether metagenomic data from respiratory bacteria derived from feedlot calves sampled in the early feeding period were associated with subsequent bovine respiratory disease (BRD) treatment and phenotypic antimicrobial resistance (AMR) at treatment. Methods: Deep nasopharyngeal swabs (DNPSs) obtained at arrival processing (1 day on feed; DOF), 13 DOF, and the time of BRD treatment were cultured and subjected to antimicrobial susceptibility testing (AST) and long-read metagenomic sequencing. Analyses focused on macrolide (mphE-msrE, EstT) and tetracycline (tet(H)) ARGs within reads assigned to Mannheimia haemolytica, Pasteurella multocida, Histophilus somni, or Bibersteinia trehalosi. Generalized estimating equations assessed associations between metagenomic results from 1 and 13 DOF and subsequent BRD treatment risk and AST outcomes at treatment, at both the individual animal (calf) and pen levels. Results: Calf-level detection of H. somni at 13 DOF was associated with a greater BRD treatment risk between 14 and 45 DOF. An increased pen prevalence of either M. haemolytica or P. multocida at 13 DOF was associated with a greater BRD treatment risk from 14 to 45 DOF. At 13 DOF, detections of mphE-msrE, EstT, or tet(H) in target bacteria were associated with corresponding phenotypic AMR at BRD treatment. Similarly, a higher pen-level prevalence of mphE-msrE or EstT at 13 DOF was also associated with increased macrolide resistance at BRD treatment. Conclusions: The results from long-read metagenomic sequencing of DNPSs collected at 13 DOF were associated with both BRD risk and AMR at treatment. These findings align with prior culture-based results and support the potential utility of pen-level metagenomic testing for AMR surveillance and informing antimicrobial selection in feedlots. Full article

Chronic coronary syndrome (CCS) and atrial fibrillation (AF) are prevalent cardiovascular conditions that share numerous risk factors and pathophysiological mechanisms. While clinical scores commonly used in AF—such as CHA₂DS₂VA (which includes congestive heart failure, hypertension, age ≥ 75, diabetes, stroke/TIA, vascular disease, and age 65–74), HAS-BLED (which incorporates hypertension, abnormal renal/liver function, stroke, bleeding history, labile INR, elderly age, and drug/alcohol use), and C₂HEST (incorporating coronary artery disease, COPD, hypertension, elderly age ≥ 75, systolic heart failure, and thyroid disease)—are traditionally applied to rhythm or bleeding risk prediction, their value in estimating the angiographic severity of coronary artery disease (CAD) remains underexplored. We conducted a prospective, single-center study including 131 patients with suspected stable CAD referred for coronary angiography, stratified according to coronary angiographic findings into two groups: significant coronary stenosis (S-CCS) and non-significant coronary stenosis (N-CCS). At admission, AF-related scores (CHA₂DS₂, CHA₂DS₂VA, CHA₂DS₂VA-HSF, CHA₂DS₂VA-RAF, CHA₂DS₂VA-LAF, HAS-BLED, C₂HEST, and HATCH) were calculated. CAD severity was subsequently assessed using the SYNTAX and Gensini scores. Statistical comparisons and Pearson correlation analyses were performed to evaluate the association between clinical risk scores and angiographic findings. Patients in the S-CCS group had significantly higher scores in CHA₂DS₂VA (4.09 ± 1.656 vs. 3.20 ± 1.338, p = 0.002), HAS-BLED (1.98 ± 0.760 vs. 1.36 ± 0.835, p < 0.001), CHA₂DS₂VA-HSF (6.00 ± 1.854 vs. 5.26 ± 1.712, p = 0.021), and C₂HEST (3.49 ± 1.501 vs. 2.55 ± 1.279, p < 0.001). Multivariate logistic regression identified HAS-BLED and C₂HEST as independent predictors of significant coronary lesions. A threshold value of HAS-BLED ≥ 1.5 and C₂HEST ≥ 3.5 demonstrated moderate discriminative ability (AUC = 0.694 and 0.682, respectively), with acceptable sensitivity and specificity. These scores also demonstrated moderate to strong correlations with both Gensini and SYNTAX scores. AF-related clinical scores, especially HAS-BLED and C₂HEST, may serve as practical and accessible tools for early CAD risk stratification in patients with suspected CCS. Their application in clinical practice may serve as supplementary triage tools to help prioritize patients for further diagnostic evaluation, but they are not intended to replace standard imaging or testing. Full article

Small non-coding microRNAs (miRNAs) play crucial roles in the degradation of the messenger RNAs (mRNAs) that are involved in various biological processes post-transcriptionally and translationally. Many plants, especially Musa spp. (plantains and bananas), which are important perennial herbs of the family Musaceae, experience significant yield loss due to abiotic stressors, yet only a few miRNAs involved in this response have been identified. This study employed in silico analyses of transcriptome shotgun assembly (TSA) and expressed sequence tag (EST) sequences to identify Musa miRNAs and their target genes. Leaf and root tissues from three Musa genomic groups (AAA, AAB, and ABB) under drought stress were analyzed using quantitative real-time PCR (qRT-PCR) to validate the expression of miRNAs. A total of 17 potential conserved miRNAs from 11 families were identified, with the minimal folding free energies (-kcal/mol) of precursors ranging from −136.00 to −55.70, as observed through RNA folding analysis. Six miRNAs (miR530-5p, miR528-5p, miR482a, miR397a, miR160h, and miR399a) showed distinct tissue-specific expression patterns in the roots and leaves across the three groups. A total of 59 target regulatory transcription factors and enzymes involved in stress response, growth, and metabolism were predicted. Of these, 11 targets were validated for miR530-5p, miR528-5p, miR482a, and miR397a, using qRT-PCR. These four stress-responsive miRNAs exhibited an inverse expression relationship with their target genes across two different tissues in Musa groups. This research provides insights into miRNA-mediated drought stress responsiveness in Musa spp., potentially benefiting future studies on gene regulation under drought stress. Full article

Background: Gloriosa superba L., commonly known as Glory Lily, is a medicinally valuable perennial climber native to tropical and subtropical regions of India. It is known for its rich alkaloid content, including colchicine and colchicoside, which contribute to its therapeutic potential in treating various ailments. Despite its pharmacological significance, genomic research on G. superba remains limited due to the lack of genetic markers, hindering molecular studies and breeding advancements. Methods: This study utilized a previously reported de novo transcriptome assembly of G. superba, identifying 14,672 EST-SSRs as genomic markers to assess genetic variations across different accessions. Genetic diversity was examined using SSR markers, while 20 morphological traits were systematically evaluated across 19 G. superba accessions from diverse geographic regions to provide insights into trait variability. Results: The most highly variable traits included plant height, number of leaves per plant, number of branches per plant, fresh pod yield, fresh seed yield, dry seed yield, number of pods per plant, leaf width, and internodal length, with coefficients of variation (CV) ranging from 63.53% to 22.45%. Intermediate CV values (10.05% to 18.75%) were observed in eight traits, while three traits (days to flowering, days to 50% flowering, and colchicine content) had low variation (<5%). Principal component analysis (PCA) accounted for 51.3% of phenotypic variation, with PC1 and PC2 contributing 29.4% and 21.9%, respectively. Clustering analysis grouped the 19 G. superba accessions into two main clusters and four sub-clusters, highlighting significant genetic divergence, with the highest dissimilarity (81.45%) observed between accessions from Arrupukottai and Pachmarhi. SSR analysis using 112 markers revealed high polymorphism but a relatively low heterozygosity index (H = 0.277) and PIC values of individual SSRs ranged from 0.26069 in RGM-51635 to 0.4534 in RGM-24219. Conclusions: The genetic divergence observed among the collected G. superba ecotypes provides valuable insights for future breeding programs aimed at enhancing cultivation efficiency and developing superior varieties with improved yield and colchicine content. Full article