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1.
World J Psychiatry ; 14(6): 794-803, 2024 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-38984340

RESUMEN

BACKGROUND: Accumulating evidence suggests that the inflammatory cytokine interleukin-6 (IL-6) contributes to the pathophysiology of psychiatric disorders. However, there was no study concerning the relationship between IL-6 concentrations and clinical features in the chronic phase of early-onset schizophrenia (EOS). AIM: To investigate the relationship between serum IL-6 concentration and the clinical features of EOS. METHODS: We measured serum IL-6 Levels from 74 patients with chronic schizophrenia, including 33 with age at onset < 21 years (EOS group) and 41 with onset ≥ 21 years in [adult-onset schizophrenia (AOS) group], and from 41 healthy controls. Symptom severities were evaluated using the Positive and Negative Syndrome Scale (PANSS). RESULTS: Serum IL-6 concentrations were higher in both EOS and AOS groups than healthy controls (F = 22.32, P < 0.01), but did not differ significantly between EOS and AOS groups (P > 0.05) after controlling for age, body mass index, and other covariates. Negative symptom scores were higher in the EOS group than the AOS group (F = 6.199, P = 0.015). Serum IL-6 concentrations in the EOS group were negatively correlated with both total PANSS-negative symptom score (r = -0.389, P = 0.032) and avolition/asociality subscore (r = -0.387, P = 0.026). CONCLUSION: Patients with EOS may have more severe negative symptoms than those with adult-onset schizophrenia during the chronic phase of the illness. IL-6 signaling may regulate negative symptoms and its avolition/asociality subsymptoms among the early-onset chronic schizophrenic patients.

2.
Sensors (Basel) ; 24(13)2024 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-39000921

RESUMEN

The current deep learning methods for copy-move forgery detection (CMFD) are mostly based on deep convolutional neural networks, which frequently discard a large amount of detail information throughout convolutional feature extraction and have poor long-range information extraction capabilities. The Transformer structure is adept at modeling global context information, but the patch-wise self-attention calculation still neglects the extraction of details in local regions that have been tampered with. A local-information-refined dual-branch network, LBRT (Local Branch Refinement Transformer), is designed in this study. It performs Transformer encoding on the global patches segmented from the image and local patches re-segmented from the global patches using a global modeling branch and a local refinement branch, respectively. The self-attention features from both branches are precisely fused, and the fused feature map is then up-sampled and decoded. Therefore, LBRT considers both global semantic information modeling and local detail information refinement. The experimental results show that LBRT outperforms several state-of-the-art CMFD methods on the USCISI dataset, CASIA CMFD dataset, and DEFACTO CMFD dataset.

3.
Sensors (Basel) ; 24(13)2024 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-39001047

RESUMEN

The Broad Learning System (BLS) has demonstrated strong performance across a variety of problems. However, BLS based on the Minimum Mean Square Error (MMSE) criterion is highly sensitive to label noise. To enhance the robustness of BLS in environments with label noise, a function called Logarithm Kernel (LK) is designed to reweight the samples for outputting weights during the training of BLS in order to construct a Logarithm Kernel-based BLS (L-BLS) in this paper. Additionally, for image databases with numerous features, a Mixture Autoencoder (MAE) is designed to construct more representative feature nodes of BLS in complex label noise environments. For the MAE, two corresponding versions of BLS, MAEBLS, and L-MAEBLS were also developed. The extensive experiments validate the robustness and effectiveness of the proposed L-BLS, and MAE can provide more representative feature nodes for the corresponding version of BLS.

4.
ACS Chem Biol ; 2024 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-38912606

RESUMEN

tRNA modifications help maintain tRNA structure and facilitate translation and stress response. Found in all three kingdoms of life, m1A tRNA modification occurs in the T loop of many tRNAs, stabilizes tertiary tRNA structure, and impacts translation. M1A in the T loop is reversible by three mammalian demethylase enzymes, which bypasses the need of turning over the tRNA molecule to adjust its m1A levels in cells. However, no prokaryotic tRNA demethylase enzyme has been identified that acts on endogenous RNA modifications. Using Streptomyces venezuelae as a model organism, we confirmed the presence and quantitative m1A tRNA signatures using mass spectrometry and high-throughput tRNA sequencing. We identified two RNA demethylases that can remove m1A in tRNA and validated the activity of a previously annotated tRNA m1A writer. Using single-gene knockouts of these erasers and the m1A writer, we found dynamic changes of m1A levels in many tRNAs under stress conditions. Phenotypic characterization highlighted changes in their growth and altered antibiotic production. Our identification of the first prokaryotic tRNA demethylase enzyme paves the way for investigating new mechanisms of translational regulation in bacteria.

5.
Artículo en Inglés | MEDLINE | ID: mdl-38836722

RESUMEN

Objective: This meta-analysis aims to investigate the effects of prenatal prophylactic antibiotics on the diversity of intestinal flora in premature infants, with a focus on elucidating the rationale behind this investigation and the potential impact of altered intestinal flora on the health of preterm infants, such as increased susceptibility to infections, impaired nutrient absorption, and compromised immune function. Methods: Relevant literature consistent with the effects of prenatal prophylactic antibiotics on intestinal flora diversity in preterm infants was systematically searched and screened from both domestic and foreign databases, including Wanfang Medical Center, CNKNET, VIpp, and PubMed. Meta-analysis was performed using RevMan 5.2 software. Inclusion criteria for the study were: (1) comparison of prophylactic antibiotic use versus non-use, (2) no restrictions on subjects' characteristics, (3) follow-up loss < 20%, (4) institutional approval, (5) publication within the time frame from January 2017 to December 2022, (6) minimal missing data or suppliable by author contact, and (7) no major errors in sequencing or detection. Outcome measures included intestinal flora composition, phylum flora content, abundance index, and Shannon index, comparing antibiotic-treated and non-treated groups. RevMan 5.2 software was used for statistical analysis. Counting data was expressed as risk ratio (RR), and weighted mean difference (WMD) or standard mean difference (SMD) was selected as analysis statistics. Results: The study encompassed five Chinese literature sources, with one deemed low quality and four high quality. No significant publication bias was observed. Among the included studies, a significant reduction in the intestinal flora abundance index ACE was noted in the treated group compared to the non-treated group (RR: -8.10, 95% CI: -8.81 to -7.40, P < .00001). ACE estimates species richness in a microbial community by considering both abundant and rare species. Higher ACE values indicate greater diversity. Similarly, the Shannon diversity index was lower in the medication group compared to the non-medication group (RR: 0.73, 95% CI: 0.64 to 0.82, P < .00001). Shannon Diversity Index measures species diversity and evenness within a community. Higher values indicate higher diversity, considering both the number of species and their relative abundance. Analysis of Firmicutes content revealed a higher level in the treated group (RR: -6.44, 95% CI: -7.26 to -5.63, P < .00001). Additionally, lower Proteus (RR: 10.96, 95% CI: 9.47 to 12.45, P < .00001) and Klebsiella (RR: 15.96, 95% CI: 15.31 to 16.62, P < .00001) content was observed in the treated group. Conversely, Enterococcus content was higher in the treated group (RR: 2.18, 95% CI: 1.84 to 2.52, P < .00001), along with a higher proportion of Enterococcus (RR: 0.45, 95% CI: 0.27 to 0.76, P = .003). These findings collectively suggest that prophylactic antibiotic use in preterm infants significantly alters the composition of intestinal flora. Conclusion: Our findings suggest that prophylactic antibiotic use in preterm infants leads to a notable reduction in intestinal flora diversity, potentially impacting their health outcomes. Decreased microbial diversity has been linked to gastrointestinal issues, infections, and weakened immune function. These results highlight the importance of cautious antibiotic use in this vulnerable population and the need for further research to better understand and mitigate the potential health implications.

6.
Anal Chim Acta ; 1315: 342825, 2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-38879210

RESUMEN

BACKGROUND: Non-invasive indirect blood glucose monitoring can be realized by detecting low concentrations of glucose (0.05-5 mM) in tears, but sensitive optical indicators are required. The intensity of the phosphorescence of a candidate optical indicator, palladium hematoporphyrin monomethyl ether (Pd-HMME), is increased by oxygen consumption under sealed conditions in the presence of glucose and glucose oxidase. However, the glucose detection limit based on this mechanism is high (800 µM) because the phosphorescence is completely quenched under ambient oxygen conditions and hence a large amount of glucose is required to reduce the oxygen levels such that the phosphorescence signal is detectable. RESULTS: To improve the glucose detection limit of Pd-HMME phosphorescence-based methods, the triplet protector imidazole was introduced, and strong phosphorescence was observed under ambient oxygen conditions. Detectable phosphorescence enhancement occurred at low glucose concentrations (<200 µM). Linear correlation between the phosphorescence intensity and glucose concentration was observed in the range of 30-727 µM (R2 = 99.9 %), and the detection limit was ∼10 µM. The glucose sensor has a fast response time (∼90 s) and excellent selectivity for glucose. SIGNIFICANCE AND NOVELTY: These results indicate the potential of the developed optical indicator for fast, selective, and reliable low-concentration glucose sensing.


Asunto(s)
Límite de Detección , Mediciones Luminiscentes , Mediciones Luminiscentes/métodos , Hematoporfirinas/química , Hematoporfirinas/análisis , Paladio/química , Glucosa/análisis , Glucosa Oxidasa/química , Glucosa Oxidasa/metabolismo , Glucemia/análisis , Imidazoles/química , Técnicas Biosensibles/métodos , Oxígeno/química , Humanos
7.
BMC Public Health ; 24(1): 1613, 2024 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-38886687

RESUMEN

BACKGROUND: the salutogenic theory is essential to explain an individual's ability to maintain health during the perinatal period. While previous studies mainly focused on the perspectives from a family-level orientation and a global orientation, the purpose of the present study was to develop and validate a scale, the childbearing sense of coherence scale (CSOC-scale) from the individual's perceptions of the stresses, resources, and meaningfulness of childbearing. METHODS: A total of 3 separate studies contributed to the development of the CSOC-scale between July 2022 and February 2023. In study 1, the initial item pool based on the conceptual framework of the childbearing sense of coherence and the salutogenic theory was developed. Delphi expert consultation was conducted to revise and improve items. Studies 2 and 3 were cross-sectional studies. In study 2, item analysis and explore factor analysis (EFA) (N = 351 for women, N = 256 for men) were used to screen items. In study 3, confirmatory factor analysis (CFA) and reliability analysis (N = 366 for women, N = 308 for men) were used to test the fit indices and reliability of the final scale. RESULTS: final analysis suggested the CSOC-scale includes three factors, consisting of 13 items. Confirmatory factor analysis demonstrated good model fit (χ2 = 157.448, df = 62, χ2/ df = 2.539, RMSEA = 0.065, CFI = 0.974, TLI = 0.968, SRMR = 0.029 for women; χ2 = 181.363, df = 62, χ2/ df = 2.925, RMSEA = 0.079, CFI = 0.968, TLI = 0.960, SRMR = 0.033 for men) and high factor loadings (from 0.751 to 0.929 for women; from 0.746 to 0.947 for men). Internal consistency (Cronbach's α ranging from 0.895 to 0.933 for women and 0.881 to 0.945 for men in three dimensions; Cronbach's α was 0.919 for women and 0.821 for men in the entire instrument) and split-half reliability (Spearman-Brown coefficients ranging from 0.876 to 0.921 for women and 0.841 to 0.937 for men in three dimensions; Spearman-Brown coefficient was 0.744 for women and 0.785 for men in the entire instrument) were excellent. CONCLUSIONS: the CSOC-scale has robust psychometric properties. It is reliable and valid in evaluating the childbearing sense of coherence in women and men during pregnancy. Utilisation of this scale can help healthcare professionals understand the health maintenance competencies of couples during the transition of parenthood and provide health promotion services from a salutogenic perspective.


Asunto(s)
Psicometría , Sentido de Coherencia , Humanos , Femenino , Masculino , Adulto , Reproducibilidad de los Resultados , Análisis Factorial , Encuestas y Cuestionarios/normas , Estudios Transversales , Técnica Delphi , Adulto Joven , Embarazo , Persona de Mediana Edad
8.
Plants (Basel) ; 13(9)2024 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-38732430

RESUMEN

Salt stress is one of the major abiotic stresses that damage the structure and composition of cell walls. Alginate oligosaccharides (AOS) have been advocated to significantly improve plant stress tolerance. The metabolic mechanism by which AOS induces salt tolerance in rice cell walls remains unclear. Here, we report the impact of AOS foliar application on the cell wall composition of rice seedlings using the salt-tolerant rice variety FL478 and the salt-sensitive variety IR29. Data revealed that salt stress decreased biomass, stem basal width, stem breaking strength, and lodging resistance; however, it increased cell wall thickness. In leaves, exogenous AOS up-regulated the expression level of OSCESA8, increased abscisic acid (ABA) and brassinosteroids (BR) content, and increased ß-galacturonic activity, polygalacturonase activity, xylanase activity, laccase activity, biomass, and cellulose content. Moreover, AOS down-regulated the expression levels of OSMYB46 and OSIRX10 and decreased cell wall hemicellulose, pectin, and lignin content to maintain cell wall stability under salt stress. In stems, AOS increased phenylalamine ammonia-lyase and tyrosine ammonia-lyase activities, while decreasing cellulase, laccase, and ß-glucanase activities. Furthermore, AOS improved the biomass and stem basal width and also enhanced the cellulose, pectin, and lignin content of the stem, As a result, increased resistance to stem breakage strength and alleviated salt stress-induced damage, thus enhancing the lodging resistance. Under salt stress, AOS regulates phytohormones and modifies cellulose, hemicellulose, lignin, and pectin metabolism to maintain cell wall structure and improve stem resistance to lodging. This study aims to alleviate salt stress damage to rice cell walls, enhance resistance to lodging, and improve salt tolerance in rice by exogenous application of AOS.

9.
Microb Cell Fact ; 23(1): 149, 2024 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-38790014

RESUMEN

BACKGROUND: Streptomyces is renowned for its robust biosynthetic capacity in producing medically relevant natural products. However, the majority of natural products biosynthetic gene clusters (BGCs) either yield low amounts of natural products or remain cryptic under standard laboratory conditions. Various heterologous production hosts have been engineered to address these challenges, and yet the successful activation of BGCs has still been limited. In our search for a valuable addition to the heterologous host panel, we identified the strain Streptomyces sp. A4420, which exhibited rapid initial growth and a high metabolic capacity, prompting further exploration of its potential. RESULTS: We engineered a polyketide-focused chassis strain based on Streptomyces sp. A4420 (CH strain) by deleting 9 native polyketide BGCs. The resulting metabolically simplified organism exhibited consistent sporulation and growth, surpassing the performance of most existing Streptomyces based chassis strains in standard liquid growth media. Four distinct polyketide BGCs were chosen and expressed in various heterologous hosts, including the Streptomyces sp. A4420 wild-type and CH strains, alongside Streptomyces coelicolor M1152, Streptomyces lividans TK24, Streptomyces albus J1074, and Streptomyces venezuelae NRRL B-65442. Remarkably, only the Streptomyces sp. A4420 CH strain demonstrated the capability to produce all metabolites under every condition outperforming its parental strain and other tested organisms. To enhance visualization and comparison of the tested strains, we developed a matrix-like analysis involving 15 parameters. This comprehensive analysis unequivocally illustrated the significant potential of the new strain to become a popular heterologous host. CONCLUSION: Our engineered Streptomyces sp. A4420 CH strain exhibits promising attributes for the heterologous expression of natural products with a focus on polyketides, offering an alternative choice in the arsenal of heterologous production strains. As genomics and cloning strategies progress, establishment of a diverse panel of heterologous production hosts will be crucial for expediting the discovery and production of medically relevant natural products derived from Streptomyces.


Asunto(s)
Productos Biológicos , Ingeniería Metabólica , Familia de Multigenes , Policétidos , Streptomyces , Streptomyces/genética , Streptomyces/metabolismo , Productos Biológicos/metabolismo , Policétidos/metabolismo , Streptomyces coelicolor/genética , Streptomyces coelicolor/metabolismo , Streptomyces lividans/genética , Streptomyces lividans/metabolismo , Vías Biosintéticas/genética
10.
Microb Cell Fact ; 23(1): 141, 2024 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-38760782

RESUMEN

BACKGROUND: The oleaginous yeast Rhodotorula toruloides is a promising chassis organism for the biomanufacturing of value-added bioproducts. It can accumulate lipids at a high fraction of biomass. However, metabolic engineering efforts in this organism have progressed at a slower pace than those in more extensively studied yeasts. Few studies have investigated the lipid accumulation phenotype exhibited by R. toruloides under nitrogen limitation conditions. Consequently, there have been only a few studies exploiting the lipid metabolism for higher product titers. RESULTS: We performed a multi-omic investigation of the lipid accumulation phenotype under nitrogen limitation. Specifically, we performed comparative transcriptomic and lipidomic analysis of the oleaginous yeast under nitrogen-sufficient and nitrogen deficient conditions. Clustering analysis of transcriptomic data was used to identify the growth phase where nitrogen-deficient cultures diverged from the baseline conditions. Independently, lipidomic data was used to identify that lipid fractions shifted from mostly phospholipids to mostly storage lipids under the nitrogen-deficient phenotype. Through an integrative lens of transcriptomic and lipidomic analysis, we discovered that R. toruloides undergoes lipid remodeling during nitrogen limitation, wherein the pool of phospholipids gets remodeled to mostly storage lipids. We identify specific mRNAs and pathways that are strongly correlated with an increase in lipid levels, thus identifying putative targets for engineering greater lipid accumulation in R. toruloides. One surprising pathway identified was related to inositol phosphate metabolism, suggesting further inquiry into its role in lipid accumulation. CONCLUSIONS: Integrative analysis identified the specific biosynthetic pathways that are differentially regulated during lipid remodeling. This insight into the mechanisms of lipid accumulation can lead to the success of future metabolic engineering strategies for overproduction of oleochemicals.


Asunto(s)
Metabolismo de los Lípidos , Nitrógeno , Rhodotorula , Rhodotorula/metabolismo , Rhodotorula/genética , Nitrógeno/metabolismo , Transcriptoma , Ingeniería Metabólica/métodos , Fosfolípidos/metabolismo , Lipidómica , Lípidos/biosíntesis
11.
Nat Commun ; 15(1): 3823, 2024 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-38714643

RESUMEN

The CRISPR-Cas12a system is more advantageous than the widely used CRISPR-Cas9 system in terms of specificity and multiplexibility. However, its on-target editing efficiency is typically much lower than that of the CRISPR-Cas9 system. Here we improved its on-target editing efficiency by simply incorporating 2-aminoadenine (base Z, which alters canonical Watson-Crick base pairing) into the crRNA to increase the binding affinity between crRNA and its complementary DNA target. The resulting CRISPR-Cas12a (named zCRISPR-Cas12a thereafter) shows an on-target editing efficiency comparable to that of the CRISPR-Cas9 system but with much lower off-target effects than the CRISPR-Cas9 system in mammalian cells. In addition, zCRISPR-Cas12a can be used for precise gene knock-in and highly efficient multiplex genome editing. Overall, the zCRISPR-Cas12a system is superior to the CRISPR-Cas9 system, and our simple crRNA engineering strategy may be extended to other CRISPR-Cas family members as well as their derivatives.


Asunto(s)
Sistemas CRISPR-Cas , Edición Génica , Edición Génica/métodos , Humanos , Células HEK293 , ARN Guía de Sistemas CRISPR-Cas/genética , ARN Guía de Sistemas CRISPR-Cas/metabolismo , ARN/genética , ARN/metabolismo , Proteínas Asociadas a CRISPR/metabolismo , Proteínas Asociadas a CRISPR/genética , Proteínas Bacterianas , Endodesoxirribonucleasas
12.
BMC Oral Health ; 24(1): 594, 2024 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-38778380

RESUMEN

BACKGROUND: Oral frailty has become a worldwide problem among older adults. Although researchers have conducted various studies on oral frailty, its definition remains controversial. PURPOSE: To clarify the concept of oral frailty. METHODS: Online databases PubMed, Web of Science, CINAHL, Cochrane Library, ProQuest, China National Knowledge Infrastructure (CNKI), China Science and Technology Journal Database (VIP), and Wanfang database were searched from inception to September 20, 2023. The reference lists of relevant studies were searched manually. Eligible articles, theses, and books were analyzed using Walker & Avant's concept analysis model. RESULTS: The attributes of oral frailty were abnormal oral structure and/or decline in multi-faceted oral function and coexisting decline in physical, cognitive and social functions. Its antecedents were aging, social frailty, and severe periodontitis, whereas its consequences were decline in physical health and mental health, social withdrawal, lower quality of life and systemic frailty. CONCLUSION: Oral frailty could result in worse conditions among older adults physically, psychologically and socially. Tools based on the concept analysis need to be developed to comprehensively assess oral frailty.


Asunto(s)
Fragilidad , Salud Bucal , Anciano , Humanos , Envejecimiento/psicología , Envejecimiento/fisiología , Anciano Frágil , Fragilidad/complicaciones , Calidad de Vida
13.
Anal Chem ; 96(15): 6037-6044, 2024 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-38560885

RESUMEN

Dopamine (DA), an essential neurotransmitter, is closely associated with various neurological disorders, whose real-time dynamic monitoring is significant for evaluating the physiological activities of neurons. Electrochemical sensing methods are commonly used to determine DA, but they mostly rely on the redox reaction of its o-phenolic hydroxyl group, which makes it difficult to distinguish it from substances with this group. Here, we design a biomimetic nanozyme inspired by the coordination structure of the copper-based active site of dopamine ß-hydroxylase, which was successfully synthesized via a urea-mediated MOF pyrolysis reconstruction strategy. Experimental studies and theoretical calculations revealed that the nanozyme with Cu-N3 coordination could hydroxylate the carbon atom of the DA ß-site at a suitable potential and that the active sites of this Cu-N3 structure have the lowest binding energy for the DA ß-site. With this property, the new oxidation peak achieves the specific detection of DA rather than the traditional electrochemical signal of o-phenol hydroxyl redox, which would effectively differentiate it from neurotransmitters, such as norepinephrine and epinephrine. The sensor exhibited good monitoring capability in DA concentrations from 0.05 to 16.7 µM, and its limit of detection was 0.03 µM. Finally, the sensor enables the monitoring of DA released from living cells and can be used to quantitatively analyze the effect of polystyrene microplastics on the amount of DA released. The research provides a method for highly specific monitoring of DA and technical support for initial screening for neurocytotoxicity of pollutants.


Asunto(s)
Dopamina , Oxigenasas de Función Mixta , Dopamina/química , Fenol , Biomimética , Cobre , Plásticos , Pirólisis , Electrodos , Neurotransmisores , Técnicas Electroquímicas/métodos
14.
J Am Chem Soc ; 146(15): 10716-10722, 2024 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-38579164

RESUMEN

Chiral alkyl amines are common structural motifs in pharmaceuticals, natural products, synthetic intermediates, and bioactive molecules. An attractive method to prepare these molecules is the asymmetric radical hydroamination; however, this approach has not been explored with dialkyl amine-derived nitrogen-centered radicals since designing a catalytic system to generate the aminium radical cation, to suppress deleterious side reactions such as α-deprotonation and H atom abstraction, and to facilitate enantioselective hydrogen atom transfer is a formidable task. Herein, we describe the application of photoenzymatic catalysis to generate and harness the aminium radical cation for asymmetric intermolecular hydroamination. In this reaction, the flavin-dependent ene-reductase photocatalytically generates the aminium radical cation from the corresponding hydroxylamine and catalyzes the asymmetric intermolecular hydroamination to furnish the enantioenriched tertiary amine, whereby enantioinduction occurs through enzyme-mediated hydrogen atom transfer. This work highlights the use of photoenzymatic catalysis to generate and control highly reactive radical intermediates for asymmetric synthesis, addressing a long-standing challenge in chemical synthesis.

15.
Sci Total Environ ; 927: 172168, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38582120

RESUMEN

Many cities face unprecedented high temperatures with increasing extreme events. Heatwaves pose significant health risks, including cardiovascular diseases, heatstroke, and dehydration. Mapping urban near-surface air temperature (Tair) is crucial for understanding thermal exposure and addressing climate change. Previous studies relied on satellite-derived land surface temperature (LST) and stationary monitoring, but high spaio-temporal Tair mapping is still a challenge. This study optimized a mobile sensing scheme using an electric bicycle platform with environmental and image sensors, and deep learning captured local-scale urban factors. A spatio-temporal data fusion model that consisted of three parts, temporal trend extraction, locality analysis, and neighborhood effect analysis, generated hyperlocal Tair maps. The Results from Beijing demonstrated the effectiveness of the framework, achieving the lowest MAE of 0.02 °C. Optimized data collection and the new model achieved accurate temperature predictions and thermal exposure assessment. Efficiency enhanced sensing strategy was also proposed. The study highlights local-scale factors and spatio-temporal dependencies in addressing heatwaves and climate change impacts in urban areas.

16.
Chembiochem ; 25(12): e202400212, 2024 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-38648232

RESUMEN

The ß-hemolytic factor streptolysin S (SLS) is an important linear azol(in)e-containing peptide (LAP) that contributes significantly to the virulence of Streptococcus pyogenes. Despite its discovery 85 years ago, SLS has evaded structural characterizing owing to its notoriously problematic physicochemical properties. Here, we report the discovery and characterization of a structurally analogous hemolytic peptide from Enterococcus caccae, termed enterolysin S (ELS). Through heterologous expression, site-directed mutagenesis, chemoselective modification, and high-resolution mass spectrometry, we found that ELS contains an intriguing contiguous octathiazole moiety. The discovery of ELS expands our knowledge of hemolytic LAPs by adding a new member to this virulence-promoting family of modified peptides.


Asunto(s)
Enterococcus , Enterococcus/metabolismo , Tiazoles/química , Tiazoles/metabolismo , Péptidos/química , Péptidos/metabolismo , Hemólisis/efectos de los fármacos , Proteínas Bacterianas/química , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/genética , Secuencia de Aminoácidos
17.
PeerJ ; 12: e17068, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38495756

RESUMEN

The aim of this experiment was to investigate the effects of exogenous sprays of 5-aminolevulinic acid (5-ALA) and 2-Diethylaminoethyl hexanoate (DTA-6) on the growth and salt tolerance of rice (Oryza sativa L.) seedlings. This study was conducted in a solar greenhouse at Guangdong Ocean University, where 'Huanghuazhan' was selected as the test material, and 40 mg/L 5-ALA and 30 mg/L DTA-6 were applied as foliar sprays at the three-leaf-one-heart stage of rice, followed by treatment with 0.3% NaCl (W/W) 24 h later. A total of six treatments were set up as follows: (1) CK: control, (2) A: 40 mg⋅ L-1 5-ALA, (3) D: 30 mg⋅ L-1 DTA-6, (4) S: 0.3% NaCl, (5) AS: 40 mg⋅ L-1 5-ALA + 0.3% NaCl, and (6) DS: 30 mg⋅ L-1 DTA-6+0.3% NaCl. Samples were taken at 1, 4, 7, 10, and 13 d after NaCl treatment to determine the morphology and physiological and biochemical indices of rice roots. The results showed that NaCl stress significantly inhibited rice growth; disrupted the antioxidant system; increased the rates of malondialdehyde, hydrogen peroxide, and superoxide anion production; and affected the content of related hormones. Malondialdehyde content, hydrogen peroxide content, and superoxide anion production rate significantly increased from 12.57% to 21.82%, 18.12% to 63.10%, and 7.17% to 56.20%, respectively, in the S treatment group compared to the CK group. Under salt stress, foliar sprays of both 5-ALA and DTA-6 increased antioxidant enzyme activities and osmoregulatory substance content; expanded non-enzymatic antioxidant AsA and GSH content; reduced reactive oxygen species (ROS) accumulation; lowered malondialdehyde content; increased endogenous hormones GA3, JA, IAA, SA, and ZR content; and lowered ABA content in the rice root system. The MDA, H2O2, and O2- contents were reduced from 35.64% to 56.92%, 22.30% to 53.47%, and 7.06% to 20.01%, respectively, in the AS treatment group compared with the S treatment group. In the DS treatment group, the MDA, H2O2, and O2- contents were reduced from 24.60% to 51.09%, 12.14% to 59.05%, and 12.70% to 45.20%. In summary, NaCl stress exerted an inhibitory effect on the rice root system, both foliar sprays of 5-ALA and DTA-6 alleviated damage from NaCl stress on the rice root system, and the effect of 5-ALA was better than that of DTA-6.


Asunto(s)
Antioxidantes , Oryza , Humanos , Antioxidantes/metabolismo , Plantones , Reguladores del Crecimiento de las Plantas/farmacología , Peróxido de Hidrógeno/farmacología , Cloruro de Sodio/farmacología , Superóxidos/farmacología , Estrés Oxidativo , Oxígeno/farmacología , Hormonas/farmacología , Malondialdehído/farmacología
18.
Nat Chem Biol ; 2024 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-38448734

RESUMEN

Metabolic efficiency profoundly influences organismal fitness. Nonphotosynthetic organisms, from yeast to mammals, derive usable energy primarily through glycolysis and respiration. Although respiration is more energy efficient, some cells favor glycolysis even when oxygen is available (aerobic glycolysis, Warburg effect). A leading explanation is that glycolysis is more efficient in terms of ATP production per unit mass of protein (that is, faster). Through quantitative flux analysis and proteomics, we find, however, that mitochondrial respiration is actually more proteome efficient than aerobic glycolysis. This is shown across yeast strains, T cells, cancer cells, and tissues and tumors in vivo. Instead of aerobic glycolysis being valuable for fast ATP production, it correlates with high glycolytic protein expression, which promotes hypoxic growth. Aerobic glycolytic yeasts do not excel at aerobic growth but outgrow respiratory cells during oxygen limitation. We accordingly propose that aerobic glycolysis emerges from cells maintaining a proteome conducive to both aerobic and hypoxic growth.

19.
Bioresour Technol ; 399: 130641, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38552861

RESUMEN

This study presents a cost-effective strategy for producing organic acids from glucose and xylose using the acid-tolerant yeast, Issatchenkia orientalis. I. orientalis was engineered to produce lactic acid from xylose, and the resulting strain, SD108XL, successfully converted sorghum hydrolysates into lactic acid. In order to enable low-pH fermentation, a self-buffering strategy, where the lactic acid generated by the SD108XL strain during fermentation served as a buffer, was developed. As a result, the SD108 strain produced 67 g/L of lactic acid from 73 g/L of glucose and 40 g/L of xylose, simulating a sugar composition of sorghum biomass hydrolysates. Moreover, techno-economic analysis underscored the efficiency of the self-buffering strategy in streamlining the downstream process, thereby reducing production costs. These results demonstrate the potential of I. orientalis as a platform strain for the cost-effective production of organic acids from cellulosic hydrolysates.


Asunto(s)
Ácido Láctico , Pichia , Xilosa , Glucosa , Análisis Costo-Beneficio , Fermentación , Saccharomyces cerevisiae
20.
Nat Chem ; 2024 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-38528101

RESUMEN

Recent efforts in genome mining of ribosomally synthesized and post-translationally modified peptides (RiPPs) have expanded the diversity of post-translational modification chemistries. However, RiPPs are rarely reported as hybrid molecules incorporating biosynthetic machinery from other natural product families. Here we report lipoavitides, a class of RiPP/fatty-acid hybrid lipopeptides that display a unique, putatively membrane-targeting 4-hydroxy-2,4-dimethylpentanoyl (HMP)-modified N terminus. The HMP is formed via condensation of isobutyryl-coenzyme A (isobutyryl-CoA) and methylmalonyl-CoA catalysed by a 3-ketoacyl-(acyl carrier protein) synthase III enzyme, followed by successive tailoring reactions in the fatty acid biosynthetic pathway. The HMP and RiPP substructures are then connected by an acyltransferase exhibiting promiscuous activity towards the fatty acyl and RiPP substrates. Overall, the discovery of lipoavitides contributes a prototype of RiPP/fatty-acid hybrids and provides possible enzymatic tools for lipopeptide bioengineering.

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