Search Results (648)

In late 2019, a new virus, SARS-CoV-2, emerged in Wuhan, China, causing COVID-19 and the subsequent global pandemic. As of 30 April 2023, more than 774 million cases of COVID-19 had been reported worldwide, including over 7.5 million in Mexico. Despite advances in vaccination, epidemic surges of COVID-19 continued to occur globally, highlighting the importance of sharing and disseminating the experiences gained during these first years to better understand the virus’s evolution and respond accordingly. For this reason, the National Council for Science and Technology (CONACYT) organized the meeting “Challenges and Opportunities for Genomic Surveillance of SARS-CoV-2 in Mexico” from 15 to 17 August 2022, to present the efforts and results accumulated over more than two years of the pandemic. In this meeting report, we summarize the key findings of each participant and provide their contact information. Full article

The contamination of drinking water sources with selenium (Se) oxyanions, including selenite (Se(IV)) and selenate (Se(VI)), contains serious health hazards with an oral intake exceeding 400 µg/day and therefore requires urgent attention. Various natural and anthropogenic sources are responsible for high Se concentrations in aquatic environments. In addition, the chemical behavior and speciation of selenium can vary noticeably depending on the origin of the source water. The Se(VI) oxyanion is more soluble and therefore more abundant in surface water. Se levels in contaminated waters often exceed 50 µg/L and may reach several hundred µg/L, well above drinking water limits set by the World Health Organization (40 µg/L) and Germany (10 µg/L), as well as typical industrial discharge limits (5–10 µg/L). Overall, Se is difficult to remove using conventionally available physical, chemical, and biological treatment technologies. The recent literature has therefore highlighted promising advancements in Se removal using emerging technologies. These include advanced physical separation methods such as membrane-based treatment systems and engineered nanomaterials for selective Se decontamination. Additionally, other integrated approaches incorporating photocatalysis coupled adsorption processes, and bio-electrochemical systems have also demonstrated high efficiency in redox transformation and capturing of Se from contaminated water bodies. These innovative strategies may offer enhanced selectivity, removal, and recovery potential for Se-containing species. Here, a current review outlines the sources, distribution, and chemical behavior of Se in natural waters, along with its toxicity and associated health risks. It also provides a broad and multi-perspective assessment of conventional as well as emerging physical, chemical, and biological approaches for Se removal and/or recovery with further prospects for integrated and sustainable strategies. Full article

Resistive stretching sensors are currently used in healthcare robotics due to their ability to vary electrical resistance when subjected to mechanical strain. However, commercial sensors often lack the softness required for integration into soft structures. This study presents a detailed methodology to characterize fabric-based resistive stretching sensors, focusing on both static and dynamic performance, for application in a smart vascular simulator for surgical training. Five sensors, called #1–#5, were developed using conductive fabrics integrated into soft silicone. Stability and fatigue tests were performed to evaluate their behavior. The surface structure and fiber distribution were analyzed using digital microscopy and scanning electron microscopy, while element analysis was performed via Energy-Dispersive X-ray Spectroscopy. Sensors #1 and #3 are the most stable with a low relative standard deviation and good sensitivity at low strains. Sensor #3 showed the lowest hysteresis, while sensor #1 had the widest operating range (0–30% strain). Although all sensors showed non-monotonic behavior across 0–100% strain, deeper investigation suggested that the sensor response depends on the configuration of conductive paths within and between fabric layers. Soft fabric-based resistive sensors represent a promising technical solution for physical simulators for surgical training. Full article

The role of bacterial selenium metabolism in non-polluted environments remains underexplored within the selenium biogeochemical cycle. In this study, selenium-metabolizing bacteria were isolated from urban environmental samples. Among 12 isolates, 10 were identified as Citrobacter spp., while the remaining 2 were Scandinavium hiltneri and Klebsiella aerogenes. The Citrobacter isolates demonstrated high selenium-removal efficiency, removing over 95% of 5 mM selenium from the aqueous phase within one week. In contrast, S. hiltneri K24-1 and K. aerogenes K24-4 removed only 19% and 69%, respectively. A detailed investigation of five representative isolates, C. freundii K21-1, S. hiltneri K24-1, C. braakii K24-2, K. aerogenes K24-4, and C. freundii K24-5, revealed that Citrobacter spp. efficiently reduced selenate directly to elemental selenium, with minimal accumulation of selenite intermediates. These results highlight Citrobacter spp. as key selenium reducers and suggest their potential as bioindicators of selenium metabolic capacity in the environment. Full article

This study focuses on the stabilization of a natural hair dye derived from Lawsonia inermis L. (henna) and Indigofera suffruticosa (indigo). Although various formulations already exist, they are designed for immediate use and cannot be stored. Lawsonia, a primary component of the dye, tends to degrade after release. To ensure its stability, freeze-drying was implemented as a protective measure. Colorimetric analysis confirmed the dye’s ability to maintain an intense, uniform coloration even after multiple washing cycles. Stability tests demonstrate that freeze-drying effectively enhances the dye’s stability and capacity to retain its physical properties and color under various environmental conditions, demonstrating its potential for long-term use. The dye’s pH (5.05) aligns with the natural pH of hair, promoting cuticle sealing and improving hair health. Cytotoxicity tests confirmed the dye’s safety, showing no harmful effects. Gray hair exhibited a total color difference (ΔE) of 64.06 after the initial application, using natural gray hair as a reference. By the third application, ΔE increased to 69.86 and gradually decreased to 68.20 after 15 washing cycles, highlighting its long-term durability. Gray hair exposed to 720 h of UV radiation showed a ΔE of 17.34, whereas dyed gray hair exhibited a ΔE of 2.96 compared to non-UV-exposed samples. This indicates superior resistance to color degradation in dyed hair. Also, SEM imaging revealed the dye’s restorative effects, progressively improving hair cuticle structure with each application. Full article

The efficacy of two selected Metarhizium rileyi Mexican isolates (T9-21 and L8-22) against Spodoptera frugiperda was evaluated under greenhouse conditions. To this end, a suspension (1 × 10⁸ conidia/mL) of these isolates was sprayed on maize plants previously infested with six second-instar larvae. No significant differences were observed between the survival curves of the T9-21 and L8-22 isolates. Cadaver sporulation was significantly higher, and the lethal time was significantly lower with the T9-21 isolate compared with those of the L8-22 isolate (97% and 8 days vs. 70% and 10 days, respectively). Based on these results, a small-scale field trial on maize was performed to evaluate the degree of pest control achieved by the T9-21 isolate and compare it with the insecticide spinetoram, applied at a rate of 1 × 10¹³ conidia/ha and 75 mL/ha, respectively. No significant differences were observed in the proportion of larval mortality between the T9-21 isolate (0.49) and spinetoram (0.72). However, spinetoram significantly reduced natural enemies and phytophagous insect populations compared with the fungus and the control. In conclusion, M. rileyi T9-21 isolate could be a promising alternative for the control of S. frugiperda larvae. Full article

Background/Objectives: Evidence of patient experiences with heart failure with preserved ejection fraction (HFpEF) and disease impact on quality of life (QoL) is scarce. This study explored perceived impacts on QoL and healthcare experiences of HFpEF patients and their caregivers. Methods: This was a mixed-methods study with HFpEF patients, ≥40 years, New York Heart Association functional classes I-IV in Spain. Qualitative data were collected through semi-structured interviews with patients (n = 19) and caregivers (n = 17). The EuroQoL 5D-5L, Patient Global Impression of Severity, and Kansas City Cardiomyopathy Questionnaire were used to collect QoL measures. Results: The themes were as follows. (1) Impact of HFpEF on QoL; (2) new roles of informal caregiving; and (3) the increasing value of multidisciplinary care. Qualitative data were supported by a trend of worsening QoL on quantitative measures as HF progressed, despite quantitative measures not fully capturing the burden. Qualitative data further captured discrepancies of QoL perceptions. Conclusions: The impact of HFpEF on patients and their caregivers was similar to the HFrEF population’s. Insights from discrepancies between PROMs data and interviews could help with tailoring QoL questionnaires to capture the broader impact of HFpEF, identify unmet needs, and customize care. Full article

Asthma is a chronic and heterogeneous inflammatory airway disease with diverse clinical endotypes and limited curative treatment options. Recent systems biology analyses identified four potential molecular triggers—AKT1, MAPK13, STAT1, and TLR4—as candidate regulators of asthma-associated signaling pathways. This study aimed to validate the expression of these four proteins and their downstream signaling elements in peripheral blood mononuclear cells (PBMCs) from patients with allergic asthma (AA), nonallergic asthma (NA), and healthy controls (HC), to explore their potential as biomarkers or therapeutic targets. For that, PBMC samples were collected from 45 AA patients, 17 NA patients, and 15 HC subjects. Gene and protein expression of AKT1, MAPK13, STAT1, and TLR4 were quantified using RT-qPCR and Western blotting. Expression patterns were compared across groups and stratified by asthma severity. Correlations with clinical parameters (FEV1, FVC, FeNO, IgE, eosinophil counts) and treatment regimens were also assessed. All four target genes showed significantly reduced expression in asthma patients compared to controls (p < 0.001), with the most marked downregulation in NA patients. At the protein level, MAPK13 and TLR4 showed significant differential expression. Stratification by severity revealed a stepwise reduction in gene expression in AA patients, correlating with disease severity, whereas NA patients showed uniformly low expression regardless of severity. Multiple pathway-related genes, including RELA, SMAD3, NFATC1, and ALOX5, were also downregulated, particularly in NA patients. Notably, differential correlations were observed between gene expression and lung function parameters in AA vs. NA groups. In conclusion, this study supports the potential involvement of AKT1, MAPK13, STAT1, and TLR4 in asthma pathogenesis and highlights differences between allergic and nonallergic asthma at the molecular level. These proteins and their associated pathways may serve as future targets for biomarker development or endotype-specific therapies. Further studies in larger and more diverse cohorts, including functional validation, are warranted. Full article

Triatoma dimidiata is a widely distributed vector of Trypanosoma cruzi in Mexico and Central America, found across a range of habitats from sylvatic to domestic. Vector control has relied heavily on indoor residual spraying with pyrethroids; however, reinfestation and emerging resistance have limited its long-term effectiveness. In this study, we analyzed the genetic diversity and population structure of T. dimidiata from Veracruz, Oaxaca, and Yucatan using mitochondrial markers (cyt b and ND4) and screened for knockdown resistance (kdr)-type mutations in the voltage-gated sodium channel (VGSC) gene. High haplotype diversity and regional differentiation were observed, with most genetic variation occurring between populations. The ND4 marker provided greater resolution than cyt b, revealing ten haplotypes and supporting evidence of recent population expansion. Haplotype networks showed clear geographic segregation, particularly between populations east and west of the Isthmus of Tehuantepec. The L925I mutation, highly associated with pyrethroid resistance, was detected for the first time in Mexican populations of T. dimidiata, albeit at low frequencies. These findings highlight the importance of integrating population genetic data and resistance surveillance into regionally adapted vector control strategies for Chagas disease. Full article

A facile fabrication method was developed for the growth of Cu_1.8Se nanosheets (NSs) on a Cu foil substrate, enabling dual-functionality as an electrochemical sensor for H₂O₂ and an active surface-enhanced Raman scattering (SERS) substrate. The process involved the preparation of Cu(OH)₂ nanowires (NWs) via electrochemical oxidation, followed by chemical conversion to Cu_1.8Se through a selenization process. The morphology, composition, and microstructure of the resulting Cu_1.8Se NSs were systematically characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The Cu_1.8Se NSs exhibited excellent electrocatalytic activity for H₂O₂ reduction, achieving a notably low detection limit of 1.25 μM and demonstrating rapid response and high sensitivity with a linear relationship in amperometric detection. Additionally, SERS experiments using Rhodamine B as a probe molecule and the Cu_1.8Se NS/Cu foil as a substrate displayed outstanding performance, with a detection limit as low as 1 μM. The flower-like structure of the Cu_1.8Se NSs exhibited linear dependence between analyte concentration and detection signals, along with satisfactory reproducibility in dual-sensing applications. These findings underscore the scalability and potential of this fabrication approach for advanced sensor development. Full article

Background: Although COVID-19 vaccination has been effective in reducing severe illness and mortality, its differential clinical behavior in vaccinated and unvaccinated individuals during the early stages of the pandemic—especially in settings with partial coverage and real-world conditions—remains insufficiently characterized. Objective: To assess differences in clinical presentation, comorbidity prevalence, hospitalization, and mortality between vaccinated and unvaccinated patients diagnosed with SARS-CoV-2 during the early phase of the pandemic. Methods: An analytical cross-sectional study was conducted using 4625 electronic medical records of patients diagnosed with COVID-19 in Guerrero, Mexico, between 1 January and 31 December 2021. Variables included vaccination status, age, sex, comorbidities, symptom severity, clinical outcomes, and mortality. Statistical analyses involved chi-square tests, logistic regression for hospitalization probability, and Cox proportional hazards models for mortality risk. Results: Of the patients analyzed, 31.45% had received at least one vaccine dose. Fever, headache, cough, and anosmia were more frequent among vaccinated individuals (p < 0.001). Prostration and chest pain were strongly associated with hospitalization in both groups. In unvaccinated patients, smoking (OR = 4.75), obesity (OR = 3.85), and hypertension (OR = 2.94) increased hospitalization risk. Among vaccinated patients, diabetes mellitus (OR = 3.62) and hypertension (OR = 2.88) were key predictors. Vaccination was significantly associated with lower odds of hospitalization (OR = 0.38; 95% CI: 0.26–0.55) and reduced mortality risk (HR = 0.24; 95% CI: 0.08–0.71). Conclusions: Vaccination status was a significant protective factor for both hospitalization and mortality; however, clinical symptoms and comorbidity-related risks varied, highlighting the need for individualized patient management strategies. Full article

Background/Objectives: For viral entry into host cells, the spike (S) protein of coronavirus (CoV) uses its S1 domain to bind to the host receptor and S2 domain to mediate the fusion between virion and cellular membranes. The S1 domain acquired multiple mutations as the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) evolved to give rise to Variant of Concerns (VOCs) but the S2 domain has limited changes. In particular, the stem helix in S2 did not change significantly and it is fairly well-conserved across multiple beta-CoVs. In this study, we generated a murine mAb 7B2 binding to the stem helix of SARS-CoV-2. Methods: MAb 7B2 was isolated from immunized mouse and its neutralization activity was evaluated using microneutralization, plaque reduction and cell–cell fusion assays. Bio-layer interferometry was used to measure binding affinity and AlphaFold3 was used to model the antibody–antigen interface. Results: MAb 7B2 has lower virus neutralizing and membrane block activities when compared to a previously reported stem helix-binding human mAb S2P6. Alanine scanning and AlphaFold3 modeling reveals that residues K1149 and D1153 in S form a network of polar interactions with the heavy chain of 7B2. Conversely, S2P6 binding to S is not affected by alanine substitution at K1149 and D1153 as indicated by the high ipTM scores in the predicted S2P6-stem helix structure. Conclusions: Our detailed characterization of the mechanism of inhibition of 7B2 reveals its distinctive binding model from S2P6 and yields insights on multiple neutralizing and highly conserved epitopes in the S2 domain which could be key components for pan-CoV vaccine development. Full article

Selenium (Se), as a vital trace element, plays an important role in regulating the antioxidant systems of plants, strengthening photosynthetic capacity, and enhancing their stress resistance. Selenate and selenite are the dominant forms of Se available to plants in soils. This research takes highland barley as the research object, aiming to assess the impacts of plant growth, organic acid metabolite, and six transcription factor families in highland barley seedlings under varying concentrations of Na₂SeO₃. The study indicated that compared to the control group (CK), the plant height of highland barley seedlings under Se1 (0.02 g/kg Na₂SeO₃) treatment significantly increased by 66%. Under the Se2 (0.2 g/kg Na₂SeO₃) treatment, plant height significantly decreased by 28%. With Na₂SeO₃ concentration increased, the pigment content, O₂⁻ production rate, and soluble protein content in highland barley seedlings decreased, while the contents of soluble sugar, MDA, and H₂O₂ increased. Se1 treatment was found to be more beneficial for the growth and development of seedlings. The organic selenium in leaves and roots under Se2 treatment significantly increased by 1105-fold and 188-fold, respectively. The most effective migration capability from soil to leaf under Se1 or Se2 treatment was up to 6.15 or 6.56, respectively. Based on metabolomics, 30 differential metabolites of organic acids were screened from highland barley seedlings under Na₂SeO₃ treatment and showed positive correlationships with organic selenium, inorganic selenium, and total selenium in highland barley seedling leaves. Through transcriptome analysis, heatmap analysis on six major categories of transcription factors (bHLH, MYB, NAC, WRKY, GATA, and HSF) was performed. Under Se2 treatment, approximately two-thirds of the transcription factors showed high expressions. We further screened 26 differentially expressed genes (DEGs) related to Na₂SeO₃ concentration. Based on correlation analysis, there were six genes in the bHLH family, five in MYB, three in NAC, five in WRKY, and three in the GATA and HSF families that showed positive correlations with 30 differential organic acid metabolites. These results enhance our understanding of the relationship between the organic acid metabolites and transcription factor expression in highland barley seedlings under Na₂SeO₃ treatment. Full article

Background: Cytokines are effector molecules of the host immune response that have been associated with chronic inflammatory processes related to risk and a poor prognosis in cancer patients. However, the impact of these molecules on the genesis and prognosis of Neuroblastoma (NB) is uncertain. Objective: The aim of the study was to analyze serum concentrations of pro-inflammatory and anti-inflammatory cytokines in a cohort of pediatric patients with NB. Methods: We evaluated the serum levels of several cytokines with a pro-inflammatory profile (IL-8, MCP-1, IL-6, IL-1β, IFN-γ, TNF-α, IL-12 p40 and IL-12p70), and anti-inflammatory profile (IL-10 and TGF-β), in pediatric patients with NB using the ELISA method, compared to a healthy control group (non-oncology). Results: Serum levels of pro-inflammatory cytokines IL-6, TNF-α, INF-γ, IL-12, IL-8 and MCP1 were significantly elevated in patients with NB compared to healthy pediatric controls. Only the anti-inflammatory cytokine IL-10 showed high levels in patients with NB in relation to the control group, unlike the synthesis of TGF-β, which had no differences between both groups. Likewise, significant positive correlations were found between the circulating levels of IL-6 with TNF-α (r = 0.667; p ≤ 0.01), IL-6 with IL-8 (r = 0.641; p ≤ 0.01), IL-8 with TNF-α (r = 0.637; p ≤ 0.01) and IL-10 with INF-γ (r = 0.542; p ≤ 0.01) in patients with NB. The simple logistic regression analysis revealed a significant association between low serum concentrations of IL-6 and a lower risk of presenting an unfavorable tumor histology (p = 0.048); in addition, low levels of IL-12p40 (p = 0.007), IFN-γ (p = 0.006) and MCP-1 (p = 0.029) were found to be associated with a lower risk of presenting NB in disseminated stages of the disease (INSS 3 and 4). Additionally, a higher risk of death was found in patients with high levels of IL-6 (p = 0.022) and IL-8 (p = 0.04). Conclusions: Taken together, the results demonstrate that the serum levels of pro-inflammatory cytokines such as IL-6, IL-8, IFN-γ, and TNF-α could be considered serum immunological indicators with a potential prognostic role in the pathogenesis of NB. Full article

Selenium (Se) is an important micronutrient for the maintenance of human health. In China, however, the population is more severely deficient in Se. Soybean is an important grain and oil crop in the world and serves as a major dietary source. The development of Se biofortification of soybeans may be an effective measure to address human Se deficiency. Arbuscular mycorrhizal fungi (AMF) are ubiquitous soil microorganisms that can enhance nutrient uptake in host plants. So, it is necessary to investigate whether soybean inoculated with AMF can biofortificate Se. In this experiment, we studied the impact of the exogenous application of three Se species (selenite, selenate, and selenomethionine) and two AMF species (Funneliformis mosseae and Glomus versiforme) on Se uptake in soybean seedlings. The results showed that the inoculation of AMF significantly (p < 0.05) improved biomass and P concentration in soybeans. Regardless of exogenous Se addition, the inoculation of AMF improved the Se transfer factor and significantly (p < 0.05) increased Se translocation to the soybean shoot. The inoculation of AMF also significantly (p < 0.05) increased the percentage of available Se in soil with selenite addition. Based on these findings, the combined application of exogenous Se and AMF inoculation represents a viable strategy for the Se biofortification of soybeans. Full article