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The two-spotted spider mite (Tetranychus urticae Koch, TSSM) is recognized as one of the most problematic spider mite pests. However, the precise gene expression patterns across its key developmental stages remain elusive. Here, we performed a comprehensive transcriptome analysis of TSSM eggs, nymphs and adult females using publicly available RNA sequencing (RNA-seq) data to elucidate the overarching transcriptomic differences between these developmental stages. Principal component analysis and hierarchical clustering analysis unveiled distinct separations among samples across different developmental stages, regardless of their Wolbachia infection status. Differential expression analysis revealed 4,089,2,762, and 1,282 core genes specifically enriched in eggs, nymphs, and adults, respectively. KEGG and GO enrichment analyses showed upregulation of genes in eggs are associated with proteolysis, Wnt signaling pathway, DNA transcription, RNA biosynthetic and metabolic processes, as well as protein folding, sorting, and degradation pathways. Meanwhile, nymphs exhibited increased abundance of genes related to chitin/amino sugar metabolic processes, G protein-coupled receptor signaling pathways, monoatomic ion transport, and neurotransmitter transport pathways. Pathways involving sphingolipid and carbohydrate metabolic processes, proteolysis, lipid transport, and localization were particularly enriched in older females. Altogether, our findings suggest that the egg stage exhibits higher activity in cell differentiation processes, the nymph stage is more involved in chitin development, and the adult stage shows increased metabolic and reproductive activity. This study enhances our understanding of the molecular mechanisms underlying TSSM development and paves the way for further research into the intricate physiological processes of TSSM.
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Objective: Cellular pyroptosis is a pro-inflammatory mode of programmed cell death that has been identified in recent years, and studies have shown that the LncRNA SOX2OT regulates myocardial injury during sepsis, but the exact regulatory mechanism is unclear. The aim of this study was to assess the role of SOX2OT in regulating cardiomyocyte injury during sepsis cardiomyopathy. Methods: Rat cardiomyocytes, C57BL/6 mice, and transgenic mice were divided into four groups: control, LPS, LPS+ knockout LncRNA SOX2OT, and LPS+ overexpression LncRNA SOX2OT. Inflammatory factor levels were detected by qPCR. Associated proteins and gene expression were detected by Western blotting and qPCR. Dual luciferase was used to detect the target genes of SOX2OT. Nrf2 and EZH2 knockdown and overexpression cell lines were established, and the expression of related genes was detected by qPCR. Results: Results In this study, we found that SOX2OT knockdown exacerbated LPS-induced levels of inflammatory factors and procalcitoninogen (PCT), and increased the expression of pyroptosis-related proteins and LDH. The results of dual luciferase reporter gene assay showed that EZH2 is the target gene of SOX2OT, and overexpression of SOX2OT decreased the expression of EZH2; we also found that knockdown of EZH2 in H9c2 cells decreased the expression of Nrf2, which was positively correlated with the expression level of NLRP3. Further in vivo results showed that overexpression of SOX2OT attenuated SIMD (sepsis-induced myocardial dysfunction), as evidenced by improved myocardial structural integrity and reduced inflammatory cell infiltration. The expression of pyroptosis-related proteins and LDH was significantly increased in the mice in the LPS group; this effect was reversed by overexpression of SOX2OT, and potentiated by knockdown of SOX2OT. Conclusion: Our data reveal a novel mechanism by which SOX2OT inhibits cardiomyocyte sepsis through the EZH2/Nrf-2/NLRP3 pathway, thereby attenuating septic myocardial injury, which may contribute to the development of new therapeutic strategies.
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Cardiac arrest most commonly occurs outside of the hospital, known as out-of-hospital cardiac arrest (OHCA), and is an important global health problem. Approximately 40% of cardiac arrest has no clear cause. Hereditary arrhythmias and cardiomyopathies factors contribute to cardiac arrest. The identification of genetic factors for cardiac arrest after its occurrence is of great value not only for the individual, but also for relatives who may be at risk for the disease in their family. In the United States, there are over 350 000 cases of OHCA and over 200 000 cases of in-hospital cardiac arrest (IHCA) each year, and in Western Europe, cardiac arrest accounts for 15%-20% of all adult natural deaths and 50% of all cardiovascular deaths. In order to reduce the burden caused by cardiac arrest within society, it is essential to further understand its etiological factors, such as incidence in different regions, risk factors, and populations at higher risk. For each individual, cardiac arrest is the result of a complex interaction of genetic and acquired factors. Understanding the complex interplay of pathogenic factors in cardiac arrest and the development of individualized prevention and treatment approaches requires the collection of clinical data from cardiac arrest populations and multimodal analysis in order to identify epidemiological features and risk factors for cardiac arrest. Recently, cardiac arrest-related data are being collected and integrated in Europe in different regions and populations. As a result of the commitment to the creation of large datasets of clinical information on cardiac arrest populations, the knowledge of the pathology of cardiac arrest pathogenesis as well as risk factors is steadily increasing. This article reviews the epidemiologic data of cardiac arrest in recent years and the associated risk factors, thus providing ideas for developing better strategies for the prevention and treatment of cardiac arrest.
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Paro Cardíaco , Humanos , Factores de Riesgo , Paro Cardíaco/epidemiología , Paro Cardíaco Extrahospitalario/epidemiologíaRESUMEN
SARS-CoV-2 infection of the upper airway and the subsequent immune response are early, critical factors in COVID-19 pathogenesis. By studying infection of human biopsies in vitro and in a hamster model in vivo, we demonstrated a transition in nasal tropism from olfactory to respiratory epithelium as the virus evolved. Analyzing each variant revealed that SARS-CoV-2 WA1 or Delta infect a proportion of olfactory neurons in addition to the primary target sustentacular cells. The Delta variant possessed broader cellular invasion capacity into the submucosa, while Omicron displayed enhanced nasal respiratory infection and longer retention in the sinonasal epithelium. The olfactory neuronal infection by WA1 and the subsequent olfactory bulb transport via axon were more pronounced in younger hosts. In addition, the observed viral clearance delay and phagocytic dysfunction in aged olfactory mucosa were accompanied by a decline of phagocytosis-related genes. Further, robust basal stem cell activation contributed to neuroepithelial regeneration and restored ACE2 expression postinfection. Together, our study characterized the nasal tropism of SARS-CoV-2 strains, immune clearance, and regeneration after infection. The shifting characteristics of viral infection at the airway portal provide insight into the variability of COVID-19 clinical features, particularly long COVID, and may suggest differing strategies for early local intervention.
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COVID-19 , Resfriado Común , Animales , Cricetinae , Humanos , Anciano , SARS-CoV-2/genética , Síndrome Post Agudo de COVID-19 , COVID-19/genética , AxonesRESUMEN
Oxidative stress (OS) and disruption of proteostasis caused by aggregated proteins are the primary causes of cell death in various diseases. Selenopeptides have shown the potential to control OS and alleviate inflammatory damage, suggesting promising therapeutic applications. However, their potential function in inhibiting proteotoxicity is not yet fully understood. To address this gap in knowledge, this study aimed to investigate the effects and underlying mechanisms of the selenopeptide VPRKL(Se)M on amyloid ß protein (Aß) toxicity in transgenic Caenorhabditis elegans. The results revealed that supplementation with VPRKL(Se)M can alleviate Aß-induced toxic effects in the transgenic C. elegans model. Moreover, the addition of VPRKL(Se)M inhibited the Aß aggregates formation, reduced the reactive oxygen species (ROS) levels, and ameliorated the overall proteostasis. Importantly, we found that the inhibitory effects of VPRKL(Se)M on Aß toxicity and activation of the unfolded protein are dependent on skinhead-1 (SKN-1). These findings suggested that VPRKL(Se)M is a potential bioactive agent for modulating SKN-1, which subsequently improves proteostasis and reduces OS. Collectively, the findings from the current study suggests VPRKL(Se)M may play a critical role in preventing protein disorder and related diseases.
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Proteínas de Caenorhabditis elegans , Cordyceps , Animales , Caenorhabditis elegans/metabolismo , Péptidos beta-Amiloides/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Cordyceps/metabolismo , Animales Modificados Genéticamente , Estrés OxidativoRESUMEN
BACKGROUND: A pineal region tumor is a rare intracranial tumor, and its specific location leads to its own characteristics. This study aimed to provide some insight for medical practice in the care of pineal region tumors. We investigated the key epidemiological characteristics and survival prognosis of pineal tumors based on the epidemiological data from the Surveillance, Epidemiology, and End Results database. METHODS: Data of pineal region tumor patients from 1975 to 2019 were extracted from the Surveillance, Epidemiology, and End Results database. The data were divided into 3 pathologic groups: germ cell tumors, pineal parenchymal tumors, and other. The patients' overall survival (OS) was analyzed using the Kaplan-Meier method. The prognostic effects of the patient characteristics on OS were explored using the Cox proportional hazard model. The analysis results are presented as tabular data, Kaplan-Meier plots, forest plots, and nomograms. A calibration curve was used to verify the nomograms. All analyses were performed for all patients overall and stratified by pathological group using SPSS and R language. RESULTS: Based on the predefined inclusion and exclusion criteria, 628 patients were included in this study, of whom 440 (70.1%) were male and 188 (29.9%) were female. Most patients were aged 0-19 years. The pathological type was germinoma for 225 patients (35.8%). Age, surgery, behavioral code, and pathology were significant factors for OS. A calibration curve was used to verify that the nomograms had a good prediction effect. CONCLUSIONS: An intuitive nomogram was developed and verified and can predict the prognosis of patients with pineal tumors.
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Neoplasias Encefálicas , Glándula Pineal , Pinealoma , Humanos , Masculino , Femenino , Pinealoma/epidemiología , Estadificación de Neoplasias , Estudios Retrospectivos , Programa de VERF , Pronóstico , Nomogramas , Neoplasias Encefálicas/epidemiologíaRESUMEN
This study aimed to compare the nutritive value and obesity prevention of ordinary Cordyceps militaris (CM) and selenium-enriched CM (SeCM). The results indicated that Se enrichment significantly increased the total carbohydrate and soluble dietary fiber content, while the protein and insoluble dietary fiber content decreased. Although the fat content was not affected, the medium and long-chain fatty acids content significantly changed. Moreover, Se enrichment significantly elevated the secondary metabolites belonging to terpenoids and alkaloids, which are linked with the enhanced biosynthesis of secondary metabolites. Both CM and SeCM reduced body weight, adipose accumulation, impaired glucose tolerance, and lipid levels in high-fat diet (HFD)-fed mice, and there was no significant difference between them. Network pharmacological analysis revealed that dietary CM and SeCM prevented HFD-induced obesity and associated metabolic diseases with multi-ingredients acting on multi-targets. Overall, Se enrichment improved the nutritive value of CM without altering its role in preventing obesity.
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This study was conducted to evaluate the effect of salt brining process parameters (salt concentration 0-15%, brining time 4-12 h, brining temperature 4-20 °C) on the quality of sous vide cooked duck meat by a single factor combined with response surface methodology (RSM). The sensory evaluation, physicochemical indexes (color, weight loss, NaCl content, TBARS value, and texture properties), and flavor characteristics were analyzed. The sensory overall mean score was applied as the evaluation index to optimize the brining conditions by RSM, and the optimum results contained a salt concentration of 11.69%, a brining temperature of 7.35 °C, and a brining time of 8.03 h. Under these conditions, the sensory overall mean score of duck meat was 8.59, with a relatively higher a* value and moderate NaCl content. GC-MS and odor activity value (OAV) results indicated that salt brining treatment significantly promoted the formation of the major odorants in duck meat, including pentanal, heptanal, octanal, (E)-2-nonenal, cis-4-decenal, decanal, 2,4-decadienal, (E,E)-2,4-decadienal, 1-heptanol, and 2-methyl-3-octanone, but decreased the content of hexanal, (E)-2-octenal, nonanal, (E,E)-2,4-nonadienal, 1-octen-3-ol, and 1-octen-3-one. 5'-nucleotides in duck meat were significantly increased after brining treatment. Therefore, salt brining treatment could be regarded as an efficient way to improve the sensory, aroma, and taste quality of sous vide cooked meat.
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Introduction: Root-knot nematode (RKN; Meloidogyne spp.) is one of the most infamous soilborne plant diseases, causing severe crop losses every year. Effector proteins secreted by RKNs play crucial roles during plant-nematode interaction. However, less is known about whether RKN effector proteins can impact the rhizosphere microbial environment. Methods: In this study, we investigated the rhizosphere microbiome community of MiMIF-2 (a plant immunity-modulating effector) transgenic Arabidopsis thaliana with or without nematode infection using the Illumina high-throughput sequencing analysis. Results and discussion: The results showed that the bacterial species richness index increased, while the fungi species richness index decreased in M. incognita-infected MiMIF-2 transgenic A. thaliana plants. The relative abundance of genera such as Clitopilus, Komagataeibacter, Lactobacillus, Prevotella, Moritella, Vibrio, Escherichia-Shigella, and Pseudomonas was reduced in MiMIF-2 transgenic A. thaliana plants compared to wild type, but was significantly increased after inoculation with M. incognita. The Cluster of Orthologous Genes (COG) function classification analysis revealed a decrease in the relative abundance of defense mechanisms, secondary metabolite biosynthesis, transport, and nematode infection catabolism-related functions in MiMIF-2 lines compared to the wild type. These differences may be the reason for the increased susceptibility of MiMIF-2 transgenic A. thaliana to nematode infection. Our results provide a new insight into RKN effector proteins and their association with the microbial community, host, and plant pathogens, which will lead to the exploration of new innovative ideas for future biological control of RKNs.
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Verticillium dahliae, one of the most destructive fungal pathogens of several crops, challenges the sustainability of cotton productivity worldwide because very few widely-cultivated Upland cotton varieties are resistant to Verticillium wilt (VW). Here, we report that REVEILLE2 (RVE2), the Myb-like transcription factor, confers the novel function in resistance to VW by regulating the jasmonic acid (JA) pathway in cotton. RVE2 expression was essentially required for the activation of JA-mediated disease-resistance response. RVE2 physically interacted with TPL/TPRs and disturbed JAZ proteins to recruit TPL and TPR1 in NINJA-dependent manner, which regulated JA response by relieving inhibited-MYC2 activity. The MYC2 then bound to RVE2 promoter for the activation of its transcription, forming feedback loop. Interestingly, a unique truncated RVE2 widely existing in D-subgenome (GhRVE2D) of natural Upland cotton represses the ability of the MYC2 to activate GhRVE2A promoter but not GausRVE2 or GbRVE2. The result could partially explain why Gossypium barbadense popularly shows higher resistance than Gossypium hirsutum. Furthermore, disturbing the JA-signalling pathway resulted into the loss of RVE2-mediated disease-resistance in various plants (Arabidopsis, tobacco and cotton). RVE2 overexpression significantly enhanced the resistance to VW. Collectively, we conclude that RVE2, a new regulatory factor, plays a pivotal role in fine-tuning JA-signalling, which would improve our understanding the mechanisms underlying the resistance to VW.
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Verticillium , Ciclopentanos/metabolismo , Oxilipinas/metabolismo , Transducción de Señal/genética , Gossypium/metabolismo , Resistencia a la Enfermedad/genética , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/microbiología , Regulación de la Expresión Génica de las Plantas/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismoRESUMEN
Selenopeptides are promising candidates for intervening in neuroinflammation; however, the key role of selenium (Se) in selenopeptides remains poorly understood. To address this gap, we compared the neuroprotective effects of selenopeptide Val-Pro-Arg-Lys-Leu-SeMet (namely, Se-P1) and its native peptide Val-Pro-Arg-Lys-Leu-Met (namely, P1). Our results demonstrate that Se-P1 treatment exhibits superior antioxidant and antineuroinflammatory effects in PC12 cells and lipopolysaccharide (LPS)-injured mice compared to P1. Moreover, the administration of Se-P1 and P1 resulted in a shift in the gut microbiota composition. Notably, during LPS-induced injury, Se-P1 treatment demonstrated greater stability in maintaining gut microbiota composition compared to P1 treatment. Specifically, Se-P1 may have a positive impact on gut microbiota dysbiosis by modulating inflammatory-related bacteria such as enhancing Lactobacillus abundance while reducing that of Lachnospiraceae_NK4A136_group. Furthermore, the alteration of metabolites induced by Se-P1 treatment exhibited a significant correlation with gut microbiota, subsequently modulating the inflammatory-related metabolic pathways including histidine metabolism, lysine degradation, and purine metabolism. These findings suggest that organic Se contributes to the bioactivities of Se-P1 in mitigating neuroinflammation in LPS-injured mice compared to P1. These findings hold significant value for the development of potential preventive or therapeutic strategies against neurodegenerative diseases and introduce novel concepts in selenopeptide nutrition and supplementation recommendations.
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Microbioma Gastrointestinal , Fragmentos de Péptidos , Animales , Ratones , Secuencia de Aminoácidos , Lipopolisacáridos/efectos adversos , Enfermedades Neuroinflamatorias , Neuroprotección , PéptidosRESUMEN
It is well known that plant genotype can regulate phyllosphere fungi at the species level. However, little is known about how plant varieties shape the fungal communities in the phyllosphere. In this study, four types of maize varieties with various levels of resistances to Exserohilum turcicum were subjected to high-throughput sequencing to reveal the properties that influences the composition of phyllosphere fungal communities. The dominant fungi genera for all four maize varieties were Alternaria at different relative abundances, followed by Nigrospora. Hierarchical clustering analysis, non-metric multidimensional scaling and similarity analysis confirmed that the fungal communities in the phyllosphere of the four varieties were significantly different and clustered into the respective maize variety they inhabited. The findings from Redundancy Analysis (RDA) indicated that both maize resistance and leaf chemical constituents, including nitrogen, phosphorus, tannins, and flavonoids, were the major drivers in determining the composition of phyllosphere fungal communities. Among these factors, maize resistance was found to be the most influential, followed by phosphorus. The co-occurrence network of the fungal communities in the phyllosphere of highly resistant variety had higher complexity, integrity and stability compared to others maize varieties. In a conclusion, maize variety resistance and leaf chemical constituents play a major role in shaping the phyllosphere fungal community. The work proposes a link between the assembled fungal communities within the phyllosphere with maize variety that is resistant to pathogenic fungi infection.
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SARS-CoV-2 vaccines have played a crucial role in effectively reducing COVID-19 disease severity, with a new generation of vaccines that use messenger RNA (mRNA) technology being administered globally. Neutralizing antibodies have featured as the heroes of vaccine-induced immunity. However, vaccine-elicited CD8+ T cells may have a significant impact on the early protective effects of the mRNA vaccine, which are evident 12 days after initial vaccination. Vaccine-induced CD8+ T cells have been shown to respond to multiple epitopes of SARS-CoV-2 and exhibit polyfunctionality in the periphery at the early stage, even when neutralizing antibodies are scarce. Furthermore, SARS-CoV-2 mRNA vaccines induce diverse subsets of memory CD8+ T cells that persist for more than six months following vaccination. However, the protective role of CD8+ T cells in response to the SARS-CoV-2 mRNA vaccines remains a topic of debate. In addition, our understanding of CD8+ T cells in response to vaccination in the lymph nodes, where they first encounter antigen, is still limited. This review delves into the current knowledge regarding the protective role of polyfunctional CD8+ T cells in controlling the virus, the response to SARS-CoV-2 mRNA vaccines, and the contribution to supporting B cell activity and promoting immune protection in the lymph nodes.
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The ongoing climate change is predicted to induce more weather extremes such as frequent drought and high-intensity precipitation events, causing more severe drying-rewetting cycles in soil. However, it remains largely unknown how these changes will affect soil nitrogen (N)-cycling microbes and the emissions of potent greenhouse gas nitrous oxide (N2 O). Utilizing a field precipitation manipulation in a semi-arid grassland on the Loess Plateau, we examined how precipitation reduction (ca. -30%) influenced soil N2 O and carbon dioxide (CO2 ) emissions in field, and in a complementary lab-incubation with simulated drying-rewetting cycles. Results obtained showed that precipitation reduction stimulated plant root turnover and N-cycling processes, enhancing soil N2 O and CO2 emissions in field, particularly after each rainfall event. Also, high-resolution isotopic analyses revealed that field soil N2 O emissions primarily originated from nitrification process. The incubation experiment further showed that in field soils under precipitation reduction, drying-rewetting stimulated N mineralization and ammonia-oxidizing bacteria in favor of genera Nitrosospira and Nitrosovibrio, increasing nitrification and N2 O emissions. These findings suggest that moderate precipitation reduction, accompanied with changes in drying-rewetting cycles under future precipitation scenarios, may enhance N cycling processes and soil N2 O emissions in semi-arid ecosystems, feeding positively back to the ongoing climate change.
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Ecosistema , Suelo , Óxido Nitroso/análisis , Pradera , Dióxido de Carbono/análisis , Nitrógeno/análisisRESUMEN
In this study, a functionalized mesoporous silica-coated solid-phase microextraction (SPME) Arrow system was developed for the enrichment of six biogenic amines (BAs) from pork and fish samples before gas chromatographic separation with a mass spectrometer as a detector. MCM-41 was utilized as the substrate material and thereby functionalized by titanate and sodium dodecyl sulfate to adjust its surface acidity and hydrophobicity, respectively. The functionalized MCM-41 (named as MCM-T-H) was coated on a bare SPME Arrow using the dipping method and polyacrylonitrile was used as the adhesive. The extraction capacity and selectivity of the MCM-T-H-SPME Arrow for six kinds of derivatized BAs were studied and compared with commercial SPME Arrows. Experimental parameters, e.g., sample volume, derivatization reagent amount, extraction time, and desorption time, which have a dramatic effect on SPME Arrow pretreatment, were optimized. Acidity enhanced MCM-T-H coating showed a much higher affinity to derivatized BAs compared to a commercial SPME Arrow in terms of extraction capacity. In addition, hydrophobicity modification significantly reduced the interference of water molecules on the interaction between MCM-T-H and the derivatized BAs. The MCM-T-H-SPME Arrow showed efficient separation and enrichment capacity for derivatized BAs from complex matrices and therefore, the sample pretreatment time was saved. According to the experimental results, the optimal condition was to add 10 µL derivatization reagent to a 10 mL sample and maintain an agitation speed of 1250 r min-1. The MCM-T-H-SPME showed excellent reproducibility (RSD < 9.8%) and fast adsorption kinetics (30 min) and desorption kinetics (5 min) for derivatized BAs under optimal conditions. In summary, the MCM-T-H-SPME Arrow based method was employed for accurate monitoring of the variations of BAs in pork and fish, and good results were achieved.
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Dysfunctional autophagy induced by excessive reactive oxygen species (ROS) load and inflammation accelerates the development of Alzheimer's disease (AD). Recently, there has been an increasing interest in selenium-enriched ingredients (SEIs), such as selenoproteins, selenoamino acids and selenosugars, which could improve AD through antioxidant and anti-inflammation, as well as autophagy modulating effects. This review indicates that SEIs eliminate excessive ROS by activating the nuclear translocation of nuclear factor erythroid2-related factor 2 (Nrf2) and alleviate inflammation by inhibiting the mitogen-activated protein kinases (MAPKs)/nuclear factor kappa-B (NF-κB) pathway. Furthermore, they can activate the adenosine 5'-monophosphate-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) pathway, and subsequently promote amyloid beta (Aß) clearance and reduce memory impairments. SEIs are ubiquitous in many plants and microorganisms, such as Brassicaceae vegetables, yeast, and mushroom. Enzymatic hydrolysis, as well as physical processing, such as thermal, high pressure and microwave treatment, are the main techniques to modify the properties of dietary selenium. This work highlights the fact that SEIs can inhibit inflammation and oxidative stress and provides evidence that supports the potential use of these dietary materials to be a novel strategy for improving AD.
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Antenna beam deflection, along with miniaturization and wideband of the antenna is in demand for practical applications. In this paper, a cylindrical conformal array antenna with a small-tilt forward beam was designed. The microstrip antenna unit was loaded with the artificial electromagnetic structure, which reduced the size of the antenna unit. As a result, the center spacing of the array elements can be shortened with the same array element spacing. The beam deflection angle can be increased in this way without increasing the coupling effect between the parts. Changing the number of line array elements and the number of line arrays can regulate the beam width of E-field and H-field, respectively. The bandwidth of the antenna can be significantly extended by slotting the ground plane. This work implemented a cylindrical conformal array of the antenna's forward beam with a small dip angle using a cylindrical carrier as an example. The measurement results showed that the angle between the main beam and the carrier axis of the conformal antenna was less than 30°, the bandwidth was more than 30%, and the antenna volume decreased by 40.4%.
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Miniaturización , Conformación MolecularRESUMEN
The removal of trivalent arsenic (As (III)) from water has received extensive attention from researchers. Iron electrocoagulation (Fe-EC) is an efficient technology for arsenic removal. However, electrode passivation hinders the development and application of Fe-EC. In this work, an innovative Fe-EC route was developed to remove As (III) through an electrochemical-siderite packed column (ESC). Ferrous ions were produced from siderite near the anode, and hydroxide was generated near the cathode during the electrochemical decomposition of siderite. As a result, an effect of Fe-EC-like was obtained. The results showed that an excellent removal performance of As (III) (>99%) was obtained by adjusting the parameters (As (III) concentration at 10 mg/L, pH at 7, Na2SO4 at 10 mM and the hydraulic retention time at 30 min) and the oxidation rate of As (III) reached 84.12%. The mechanism analysis indicated that As (III) was oxidized to As (â ¤) by the produced active oxide species and electrode, and then was removed by capturing on the iron oxide precipitates. As (III) was likely to be oxidized in two ways, one by the reactive oxygen species (possibly â¢OH, Fe(IV) and â¢O2- species), and another directly by the anode. The long-term effectiveness of arsenic removal demonstrated that ESC process based on the electrochemical-siderite packed column was an appropriate candidate for treating As (III) pollution.
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Arsénico , Contaminantes Químicos del Agua , Purificación del Agua , Arsénico/química , Carbonatos , Compuestos Férricos , Floculación , Hierro/química , Oxidación-Reducción , Óxidos , Especies Reactivas de Oxígeno , Agua , Contaminantes Químicos del Agua/química , Purificación del Agua/métodosRESUMEN
Due to the stable chelating effect of organic phosphonates in wastewater, phosphonates with increasing emission are difficult to be removed effectively by traditional ferric salt flocculation, which has posed tough challenges for reducing total phosphorus pollution in recent years. In this work, calcium carbonate (CaCO3) was introduced to work together with the widely investigated flocculant of ferric chloride (FeCl3) to realize an efficient removal of nitrilotrismethylenephosphonic acid (NTMP) at much lower dosage of FeCl3. With an aid of synergy effect from together use of CaCO3 and FeCl3, the remaining concentration as low as 0.16 mg-P/L, far below the sewage discharge limit (0.5 mg-P/L), was simply obtained with a significantly reduced Fe/P molar ratio at only 4, resulting from calcium source donor to form more stable Fe-Ca-P tridentate bridging complexes, high affinity towards ferric ions on CaCO3 surface and slow-release alkaline from CaCO3. A comparison among sodium hydroxide (NaOH), calcium hydroxide (Ca(OH)2) and CaCO3 as additives, was carried out to highlight the advantages of using CaCO3 and clarify the mechanism for the greatly improved performance by a set of characterizations including XRD, FTIR, Zeta potential, XPS, SEM-EDS and TG analyses. The addition of CaCO3 in ferric flocculation resulted in further obvious advantages such as 75% shortened settling time and only one-third of sludge volume of the precipitant, beneficial to the sample handling in engineering application. The proposed new approach has been further confirmed to work efficiently on real phosphonate-containing wastewater. Discussion on the interaction between CaCO3 and ferric salts in phosphonate solutions shed new insights into the working mechanism of using CaCO3 for the treatment of phosphonates-containing wastewater.
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Toward the treatment of waste solution containing heavy metals, direct precipitation of the metal ions from an acidic solution without alkaline neutralisation is still the greatest challenge. Based on the ligand properties of benzene tricarboxylic acid (BTC) to copper ions, a simple ball milling with 90â min at 400â rpm was used to activate BTC to enhance its capacity for copper removal from the pH of the original solution around 3-4. A set of analytical methods were used to characterise the activated BTC sample and BTC-Cu precipitate before and after copper precipitation. Compared with the raw BTC, the activated BTC could efficiently remove copper ions over 90% from an initial copper concentration of 100â mg/L in a shorter time from an acidic media with lower pH of around 2.60 and the maximum adsorption capacity can be stable at about 111.70â mg/g, resulting from probably the enhanced deprotonation effect for copper incorporation. Furthermore, at controlled dosage, the activated BTC demonstrated much high selectivity on precipitating copper ions from other heavy metals of Ni, Mn, Zn and Cd and provided a new approach for easy copper recycling from waste solution as secondary sources. This process may serve the purpose of recycling both metal and acidic solutions after the purification.