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Objective: The aim of this investigation was to examine the impact of Taraxacum coreanum (known as dandelion) (TC) and TC mixtures with milk thistle (MT) or Aspergillus oryzae (AO) as feed additives on the immune response, milk quality, and milk production in Holstein cows over 6 weeks of administration. Materials and Methods: Thirty-two healthy Holstein dairy cows were provided 30 kg of total mixed ration (TMR) with no TC, 90 gm TC, 54 gm TC + 36 gm MT, or 54 gm TC + 36 gm AO 40% groups. The feed additives were supplied daily in two equal portions (per 45 gm) by topdressing the TMR for 6 weeks. Milk and blood samples were collected weekly. Results: In the TC-treated cows (TC, TC + MT, and TC + AO groups), significantly lower peripheral blood white blood cell (WBC) counts at 6 weeks and milk somatic cell counts (SCCs) at 4-6 weeks of administration were observed. Concentrations of serum superoxide dismutase (SOD) and glutathione peroxidase (GSH-px) were notably elevated in cows treated with TC for 4-6 weeks, while levels of proinflammatory cytokines concentrations of tumor necrosis factor-alpha (TNF-α) and chemokine (IL-8) were significantly reduced in TC-treated cows after 3-6 weeks of administration. Conclusion: These results suggested that TC or a TC mixture with other medicinal herbs supplementations enhanced the serum antioxidative activities and, consequently, might suppress the adverse immune response due to lower serum TNF-α and IL-8 release supported by lower WBC and SCC counts.
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Flavonols effectively scavenge the reactive nitrogen species (RNS) and reactive oxygen species (ROS) and act as immune-enhancing, anti-inflammatory, anti-diabetic, and anti-carcinogenic agents. Here, we explored the comparative antioxidant and anti-inflammatory properties of plant-originating flavonols, like quercetin, rutin, and troxerutin against acetylsalicylic acid. Quercetin and rutin showed a high ability to remove active ROS, but troxerutin and acetylsalicylic acid exhibited little such function. In RAW 264.7 cells, quercetin, rutin, and troxerutin did not exhibit cellular toxicity at low concentrations. In addition, quercetin, rutin, and troxerutin considerably (p < 0.05) lowered the protein expression of cyclooxygenase 2 (COX-2) as compared to acetylsalicylic acid in cells inflamed with lipopolysaccharides (LPS). Additionally, in inflamed cells, quercetin and rutin significantly down-regulated the nitrogen oxide (NO) level (p < 0.05) at higher concentrations, whereas Troxerutin did not reduce the NO level. In addition, Troxerutin down-regulated the pro-inflammatory protein markers, such as TNF-α, COX-2, NF-κB, and IL-1ß better than quercetin, rutin, and acetylsalicylic acid. We observed that troxerutin exhibited a significantly greater anti-inflammatory effect than acetylsalicylic acid did. Acetylsalicylic acid did not significantly down-regulated the expression of COX-2 and TNF-α (p < 0.05) compared to troxerutin. Hence, it can be concluded that the down-regulation of NO levels and the expression of COX-2 and TNF-α proteins could be mechanisms of action for the natural compounds quercetin, rutin, and troxerutin in preventing inflammation.
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PD1/PD-L1 checkpoint inhibitors are at the forefront of cancer immunotherapies. However, the overall response rate remains only 10-30%. Even among initial responders, drug resistance often occurs, which can lead to prolonged use of a futile therapy in the race with the fatal disease. It would be ideal to closely monitor key indicators of patients' immune responsiveness, such as circulating PD-L1 levels. Traditional PD-L1 detection methods, such as ELISA, are limited in sensitivity and rely on core lab facilities, preventing their use for the regular monitoring. Electrochemical sensors exist as an attractive candidate for point-of-care tool, yet, streamlining multiple processes in a single platform remains a challenge. To overcome this challenge, this work integrated electrochemical sensor arrays into a digital microfluidic device to combine their distinct merits, so that soluble PD-L1 (sPD-L1) molecules can be rapidly detected in a programmed and automated manner. This new platform featured microscale electrochemical sensor arrays modified with electrically conductive 3D matrix, and can detect as low as 1 pg/mL sPD-L1 with high specificity. The sensors also have desired repeatability and can obtain reproducible results on different days. To demonstrate the functionality of the device to process more complex biofluids, we used the device to detect sPD-L1 molecules secreted by human breast cancer cell line in culture media directly and observed 2X increase in signal compared with control experiment. This novel platform holds promise for the close monitoring of sPD-L1 level in human physiological fluids to evaluate the efficacy of PD-1/PD-L1 immunotherapy.
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Anti-leucine-rich glioma-inactivated 1 limbic encephalitis (anti-LGI1 LE) is a rare autoimmune limbic encephalitis with a potentially misleading presentation that can delay diagnosis and treatment. The incremental progression of widely variable symptoms with a prominent behavioral disturbance can conceal the disease and prompt an initial psychiatric diagnosis. Although specific MRI findings ought to be evident by the time the disease progresses to frank limbic encephalitis, it appears inconsistent and ill-defined and is thus unreliable. Nevertheless, brain imaging remains prominent in the discussion, even included in some guidelines for diagnosing anti-LGI1 LE. Here, we present a case of a patient who presented after a suicide attempt with a long history of psychiatric issues, aberrant "spasms," and subsequently encephalopathy, who was eventually diagnosed with anti-LGI1 LE only after delayed CSF antibodies studies. In this patient, symptoms emerged over two years, with multiple brain MRIs being negative, including the one completed during the hospital admission in focus. The purpose of this case report is to encourage maintaining a broad differential when patients present with bizarre symptoms. This report underlies the importance of thorough clinical evaluation, utilization of multiple diagnostic resources, and the need for heightened awareness among healthcare providers about the subtleties of autoimmune encephalitis presentations. With anti-LGI1 LE already being severely underdiagnosed, it is important to continue reviewing various cases of patients who are diagnosed with anti-LGI1 LE and further review to understand its pathophysiology and common clinical presentation. This case also underscores the ongoing evolution in understanding anti-LGI1 LE and highlights that patients may present with unfamiliar symptoms or diagnostic challenges. The overall objective is to help providers recognize anti-LGI1 LE earlier, so treatment can be initiated sooner, leading to a better prognosis for patients.
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Acute lung injury is an acute inflammation disorder that disrupts the lung endothelial and epithelial barriers. In this study, we investigated the extracellular vesicles (EVs) obtained via priming inflammatory cytokines such as tumor necrosis factor (TNF)-α and interferon (IFN)-γ on canine adipose mesenchymal stem cells in improving their anti-inflammatory and/or immunosuppressive potential, and/or their ability to alleviate lipopolysaccharide-induced lung injury in vitro. We also explored the correlation between epithelial-to-mesenchymal transition and the inflammatory repressive effect of primed EVs. Using small RNA-Seq, we confirmed that miR-16 and miR-502 significantly increased in EVs from TNF-α and IFN-γ-primed canine adipose mesenchymal stem cells. The pro and anti-inflammatory cytokines were analyzed in a lipopolysaccharide-induced lung injury model and we found that the EV anti-inflammatory effect improved on priming with inflammatory cytokines. EVs obtained from primed stem cells effectively suppress endothelial-to-mesenchymal transition in a lung injury model. Our results suggest a potential therapeutic approach utilizing EVs obtained from adipose mesenchymal stem cells primed with TNF-α and IFN-γ against lung inflammation and endothelial to mesenchymal transition.
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CD36 expression in both immune and non-immune cells is known to be directly involved in cancer metastasis. Extracellular vesicles (EVs) secreted by malignant melanocytes play a vital role in developing tumor-promoting microenvironments, but it is unclear whether this is mediated through CD36. To understand the role of CD36 in melanoma, we first analyzed the SKCM dataset for clinical prognosis, evaluated the percentage of CD36 in lymphatic fluid-derived EVs (LEVs), and tested whether melanoma-derived EVs increase CD36 expression and induce M2-macrophage-like characteristics. Furthermore, we performed a multiplex immunofluorescence (MxIF) imaging analysis to evaluate the CD36 expression and its colocalization with various other cells in the lymph node (LN) of patients and control subjects. Our findings show that cutaneous melanoma patients have a worse clinical prognosis with high CD36 levels, and a higher percentage of CD36 in total LEVs were found at baseline in melanoma patients compared to control. We also found that monocytic and endothelial cells treated with melanoma EVs expressed more CD36 than untreated cells. Furthermore, melanoma-derived EVs can regulate immunosuppressive macrophage-like characteristics by upregulating CD36. The spatial imaging data show that cells in tumor-involved sentinel LNs exhibit a higher probability of CD36 expression than cells from control LNs, but this was not statistically significant. Conclusively, our findings demonstrated that CD36 plays a vital role in controlling the immunosuppressive microenvironment in the LN, which can promote the formation of a protumorigenic niche.
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Antígenos CD36 , Vesículas Extracelulares , Melanoma , Microambiente Tumoral , Humanos , Vesículas Extracelulares/metabolismo , Melanoma/metabolismo , Melanoma/patologia , Antígenos CD36/metabolismo , Neoplasias Cutâneas/patologia , Neoplasias Cutâneas/metabolismo , Linhagem Celular Tumoral , Macrófagos/metabolismo , Macrófagos/patologia , Prognóstico , Feminino , Melanoma Maligno Cutâneo , Linfonodos/patologia , Linfonodos/metabolismo , MasculinoRESUMO
BACKGROUND: Scientific and clinical interest in extracellular vesicles (EVs) is growing. EVs that expose tissue factor (TF) bind factor VII/VIIa and can trigger coagulation. Highly procoagulant TF-exposing EVs are detectable in the circulation in various diseases, such as sepsis, COVID-19, or cancer. Many in-house and commercially available assays have been developed to measure EV-TF activity and antigen, but only a few studies have compared some of these assays. OBJECTIVES: The International Society on Thrombosis and Haemostasis Scientific and Standardization Committee Subcommittee on Vascular Biology initiated a multicenter study to compare the sensitivity, specificity, and reproducibility of these assays. METHODS: Platelet-depleted plasma samples were prepared from blood of healthy donors. The plasma samples were spiked either with EVs from human milk or EVs from TF-positive and TF-negative cell lines. Plasma was also prepared from whole human blood with or without lipopolysaccharide stimulation. Twenty-one laboratories measured EV-TF activity and antigen in the prepared samples using their own assays representing 18 functional and 9 antigenic assays. RESULTS: There was a large variability in the absolute values for the different EV-TF activity and antigen assays. Activity assays had higher specificity and sensitivity compared with antigen assays. In addition, there was a large intra-assay and interassay variability. Functional assays that used a blocking anti-TF antibody or immunocapture were the most specific and sensitive. Activity assays that used immunocapture had a lower coefficient of variation compared with assays that isolated EVs by high-speed centrifugation. CONCLUSION: Based on this multicenter study, we recommend measuring EV-TF using a functional assay in the presence of an anti-TF antibody.
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This study aimed to investigate effects of long-term probiotic supplementation on gut microbiota and growth performance in health weaned piglets. The non-probiotic group (N-PrB) was fed only a basal diet, while the probiotic group (PrB) was fed a basal diet + probiotic combination (E. faecium 1.6 × 108 CFU/g, B. subtilis 2.0 × 108 CFU/g, S. cerevisiae 3.0 × 108 CFU/g). The probiotics combination was provided to the PrB, mixing with the basal diet in 5 kg/ton. As a result, the PrB exhibited significantly improved weight gain compared to the N-PrB (p = 0.00991). In the gut microbiome analysis, the PrB exhibited a significant increasing tendency of α-diversity compared to those of the N-PrB (p < 0.01). In the bacterial relative abundance changes in bacteria comprising the gut microbiota, Ruminococcaceae (p = 0.00281) and Prevotella (p = 0.00687) tended to significantly increase in the PrB, but decreased in the N-PrB. The Eubaterium coprostanoligenes group exhibited an increasing tendency in both groups, but tended to increase more significantly in the PrB compared to the N-PrB (p = 0.00681). Muribaculaceae tended to significantly increase in the N-PrB, but decreased in the PrB (p = 0.002779). In this study, significant differences on the gut microbiome were found according to the probiotics supplementation in the weaned piglets and these gut microbiome changes appeared to improve the growth performance.
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Liver fibrosis is characterized by the activation of perivascular hepatic stellate cells (HSCs), the release of fibrogenic nanosized extracellular vesicles (EVs), and increased HSC glycolysis. Nevertheless, how glycolysis in HSCs coordinates fibrosis amplification through tissue zone-specific pathways remains elusive. Here, we demonstrate that HSC-specific genetic inhibition of glycolysis reduced liver fibrosis. Moreover, spatial transcriptomics revealed a fibrosis-mediated up-regulation of EV-related pathways in the liver pericentral zone, which was abrogated by glycolysis genetic inhibition. Mechanistically, glycolysis in HSCs up-regulated the expression of EV-related genes such as Ras-related protein Rab-31 (RAB31) by enhancing histone 3 lysine 9 acetylation on the promoter region, which increased EV release. Functionally, these glycolysis-dependent EVs increased fibrotic gene expression in recipient HSC. Furthermore, EVs derived from glycolysis-deficient mice abrogated liver fibrosis amplification in contrast to glycolysis-competent mouse EVs. In summary, glycolysis in HSCs amplifies liver fibrosis by promoting fibrogenic EV release in the hepatic pericentral zone, which represents a potential therapeutic target.
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Vesículas Extracelulares , Glicólise , Células Estreladas do Fígado , Cirrose Hepática , Animais , Cirrose Hepática/metabolismo , Cirrose Hepática/patologia , Cirrose Hepática/genética , Células Estreladas do Fígado/metabolismo , Células Estreladas do Fígado/patologia , Vesículas Extracelulares/metabolismo , Camundongos , Proteínas rab de Ligação ao GTP/metabolismo , Proteínas rab de Ligação ao GTP/genética , Humanos , Modelos Animais de Doenças , Fígado/metabolismo , Fígado/patologia , Camundongos Endogâmicos C57BL , MasculinoRESUMO
Synaptic loss is an early event in the penumbra area after an ischemic stroke. Promoting synaptic preservation in this area would likely improve functional neurological recovery. We aimed to detect proteins involved in endogenous protection mechanisms of synapses in the penumbra after stroke and to analyse potential beneficial effects of these candidates for a prospective stroke treatment. For this, we performed Liquid Chromatography coupled to Mass Spectrometry (LC-MS)-based proteomics of synaptosomes isolated from the ipsilateral hemispheres of mice subjected to experimental stroke at different time points (24 h, 4 and 7 days) and compared them to sham-operated mice. Proteomic analyses indicated that, among the differentially expressed proteins between the two groups, cystatin C (CysC) was significantly increased at 24 h and 4 days following stroke, before returning to steady-state levels at 7 days, thus indicating a potential transient and intrinsic rescue mechanism attempt of neurons. When CysC was applied to primary neuronal cultures subjected to an in vitro model of ischemic damage, this treatment significantly improved the preservation of synaptic structures. Notably, similar effects were observed when CysC was loaded into brain-derived extracellular vesicles (BDEVs). Finally, when CysC contained in BDEVs was administered intracerebroventricularly to stroked mice, it significantly increased the expression of synaptic markers such as SNAP25, Homer-1, and NCAM in the penumbra area compared to the group supplied with empty BDEVs. Thus, we show that CysC-loaded BDEVs promote synaptic protection after ischemic damage in vitro and in vivo, opening the possibility of a therapeutic use in stroke patients.
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Isquemia Encefálica , Encéfalo , Cistatina C , Vesículas Extracelulares , Camundongos Endogâmicos C57BL , Sinapses , Animais , Vesículas Extracelulares/metabolismo , Vesículas Extracelulares/transplante , Cistatina C/metabolismo , Sinapses/metabolismo , Camundongos , Masculino , Isquemia Encefálica/metabolismo , Isquemia Encefálica/patologia , Encéfalo/metabolismo , Encéfalo/patologia , Proteômica/métodos , Sinaptossomos/metabolismo , Neurônios/metabolismo , Acidente Vascular Cerebral/metabolismo , Acidente Vascular Cerebral/patologia , Acidente Vascular Cerebral/terapia , Células Cultivadas , Modelos Animais de DoençasRESUMO
BACKGROUND: Hypometabolism tied to mitochondrial dysfunction occurs in the aging brain and in neurodegenerative disorders, including in Alzheimer's disease, in Down syndrome, and in mouse models of these conditions. We have previously shown that mitovesicles, small extracellular vesicles (EVs) of mitochondrial origin, are altered in content and abundance in multiple brain conditions characterized by mitochondrial dysfunction. However, given their recent discovery, it is yet to be explored what mitovesicles regulate and modify, both under physiological conditions and in the diseased brain. In this study, we investigated the effects of mitovesicles on synaptic function, and the molecular players involved. METHODS: Hippocampal slices from wild-type mice were perfused with the three known types of EVs, mitovesicles, microvesicles, or exosomes, isolated from the brain of a mouse model of Down syndrome or of a diploid control and long-term potentiation (LTP) recorded. The role of the monoamine oxidases type B (MAO-B) and type A (MAO-A) in mitovesicle-driven LTP impairments was addressed by treatment of mitovesicles with the irreversible MAO inhibitors pargyline and clorgiline prior to perfusion of the hippocampal slices. RESULTS: Mitovesicles from the brain of the Down syndrome model reduced LTP within minutes of mitovesicle addition. Mitovesicles isolated from control brains did not trigger electrophysiological effects, nor did other types of brain EVs (microvesicles and exosomes) from any genotype tested. Depleting mitovesicles of their MAO-B, but not MAO-A, activity eliminated their ability to alter LTP. CONCLUSIONS: Mitovesicle impairment of LTP is a previously undescribed paracrine-like mechanism by which EVs modulate synaptic activity, demonstrating that mitovesicles are active participants in the propagation of cellular and functional homeostatic changes in the context of neurodegenerative disorders.
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Doença de Alzheimer , Síndrome de Down , Doenças Mitocondriais , Humanos , Animais , Camundongos , Espaço Extracelular , Plasticidade Neuronal , Encéfalo , Modelos Animais de Doenças , MonoaminoxidaseRESUMO
In high-density network environments with multiple access points (APs) and stations, individual uplink scheduling by each AP can severely interfere with the uplink transmissions of neighboring APs and their associated stations. In congested areas where concurrent uplink transmissions may lead to significant interference, it would be beneficial to deploy a cooperative scheduler or a central coordinating entity responsible for orchestrating cooperative uplink scheduling by assigning several neighboring APs to support the uplink transmission of a single station within a proximate service area to alleviate the excessive interference. Cooperative uplink scheduling facilitated by cooperative information sharing and management is poised to improve the likelihood of successful uplink transmissions in areas with a high concentration of APs and stations. Nonetheless, it is crucial to account for the queue stability of the stations and the potential delays arising from information exchange and the decision-making process in uplink scheduling to maintain the overall effectiveness of the cooperative approach. In this paper, we propose a Lyapunov drift-plus-penalty framework-based cooperative uplink scheduling method for densely populated Wi-Fi networks. The cooperative scheduler aggregates information, such as signal-to-interference-plus-noise ratio (SINR) and queue status. During the aggregation procedure, propagation delays are also estimated and utilized as a value of expected cooperation delays in scheduling decisions. Upon aggregating the information, the cooperative scheduler calculates the Lyapunov drift-plus-penalty value, incorporating a predefined model parameter to adjust the system accordingly. Among the possible scheduling candidates, the proposed method proceeds to make uplink decisions that aim to reduce the upper bound of the Lyapunov drift-plus-penalty value, thereby improving the network performance and stability without a severe increase in cooperation delay in highly congested areas. Through comprehensive performance evaluations, the proposed method effectively enhances network performance with an appropriate model parameter. The performance improvement is particularly notable in highly congested areas and is achieved without a severe increase in cooperation delays.
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Objectives: To update recent information on contamination levels of mycotoxins in South Korea. Materials and methods: A total of 208 samples sourced from the feeds of swine farms were collected. The contamination levels of mycotoxins, which are aflatoxin (Afla), ochratoxin A (OTA), deoxynivalenol (DON), zearalenone (ZEN), fumonisin (FUM), and T-2 toxin, were investigated by enzyme-linked immunosorbent assays (ELISAs). Results: The detection levels of the total samples were 78.91% for DON, 75.24% for Afla, 47.02% for ZEN, 68.31% for FUM, and 5.94% for OTA and T-2, which were not detected at all. Most of the analyzed mycotoxins showed significant high occurrences in 47.02%-78.91% of the swine feed samples. 11 of the 152 alfa-positive samples exceeded the maximum residue limit (MRL) of Afla proposed by the Korean regulation. In the analysis of mycotoxin detection levels by growth stage, ZEN was found in the nursery stage at a remarkably high concentration level (126.46 ± 63.76 ppb), exceeding the MRL of ZEN for piglets proposed by the European Commission. This mycotoxin was also found in the samples from the gestation barn (89.04 ± 46.05 ppb) and the farrowing house (105.58 ± 94.12) at a high concentration level. Afla was found in the nursery stage at a high concentration (8.00 ± 2.22 ppb), approaching the MRL (10 ppb) of Afla proposed by the Korean regulation. Conclusion: These results indicate that many swine farms in South Korea are still exposed to mycotoxin risk, and special attention and surveillance are necessary for these mycotoxin risks in swine farms.
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The development of exopolysaccharide-based polymers is gaining increasing attention in various industrial biotechnology fields for materials such as thickeners, texture modifiers, anti-freeze agents, antioxidants, and antibacterial agents. High-viscosity carboxyethyl-succinoglycan (CE-SG) was directly synthesized from succinoglycan (SG) isolated from Sinorhizobium meliloti Rm 1021, and its structural, rheological, and physiological properties were investigated. The viscosity of CE-SG gradually increased in proportion to the degree of carboxyethylation substitution. In particular, when the molar ratio of SG and 3-chloropropionic acid was 1:100, the viscosity was significantly improved by 21.18 times at a shear rate of 10 s-1. Increased carboxyethylation of SG also improved the thermal stability of CE-SG. Furthermore, the CE-SG solution showed 90.18 and 91.78 % antibacterial effects against Escherichia coli and Staphylococcus aureus and effective antioxidant activity against DPPH and hydroxyl radicals. In particular, CE-SG hydrogels coordinated with Fe3+ ions, which improved both viscosity and rheological properties, while also exhibiting reduction-responsive drug release through 1,4-dithiothreitol. The results of this study suggest that SG derivatives, such as CE-SG, can be used as functional biomaterials in various fields such as food, cosmetics, and pharmaceutical industries.
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Antioxidantes , Hidrogéis , Polissacarídeos Bacterianos , Hidrogéis/farmacologia , Antioxidantes/farmacologia , Antibacterianos/farmacologia , Indústria Farmacêutica , Escherichia coliRESUMO
PURPOSE: We developed machine learning (ML) models to assess demographic and socioeconomic status (SES) variables' value in predicting continued participation in a low-dose CT lung cancer screening (LCS) program. MATERIALS AND METHODS: 480 LCS subjects were retrospectively examined for the following outcomes: (#1) no follow-up (single LCS scan) vs. multiple follow-ups (220 and 260 subjects respectively) and (#2) absent or delayed (>1 month past the due date) follow-up vs timely follow-up (356 and 124 subjects respectively). We quantified the contributions of 14 socioeconomic, demographic, and clinical predictors to LCS adherence, and validated and compared prediction performances of multivariate logistic regression (MLR), support vector machine (SVM) and shallow neural network (NN) models. RESULTS: For outcome #1, age, sex, race, insurance status, personal cancer history, and median household income were found to be associated with returning for follow-ups. For outcome #2, age, sex, race, and insurance status were significant predictor of absent/delayed LCS follow-up. Across 5-fold cross-validation, the MLR model achieved an average AUC of 0.732 (95% CI, 0.661-0.803) for outcome #1 and 0.633 (95% CI, 0.602-0.664) for outcome #2 and is the model with best predictive performance overall, whereas NN and SVM tended to overfit training data and fell short on testing data performance for either outcome. CONCLUSIONS: We identified significant predictors of LCS adherence, and our ML models can predict which subjects are at higher risk of receiving no or delayed LCS follow-ups. Our results could inform data-driven interventions to engage vulnerable populations and extend the benefits of LCS.
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Detecção Precoce de Câncer , Neoplasias Pulmonares , Tomografia Computadorizada por Raios X , Humanos , Neoplasias Pulmonares/diagnóstico por imagem , Masculino , Feminino , Pessoa de Meia-Idade , Estudos Retrospectivos , Idoso , Determinantes Sociais da Saúde , Aprendizado de Máquina , Fatores Socioeconômicos , DemografiaRESUMO
Interactions between monatomic ions and water molecules are fundamental to understanding the hydration of complex polyatomic ions and ionic process. Among the simplest and well-established ion-related reactions is dissolution of salt in water, which is an endothermic process requiring an increase in entropy. Extensive efforts have been made to date; however, most studies at single-ion level have been limited to theoretical approaches. Here, we demonstrate the salt dissolution process by manipulating a single water molecule at an under-coordinated site of a sodium chloride film. Manipulation of molecule in a controlled manner enables us to understand ion-water interaction as well as dynamics of water molecules at NaCl interfaces, which are responsible for the selective dissolution of anions. The water dipole polarizes the anion in the NaCl ionic crystal, resulting in strong anion-water interaction and weakening of the ionic bonds. Our results provide insights into a simple but important elementary step of the single-ion chemistry, which may be useful in ion-related sciences and technologies.
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Copper (Cu) is a widely used catalyst for the nitrate reduction reaction (NO3RR), but its susceptibility to surface oxidation and complex electrochemical conditions hinders the identification of active sites. Here, we employed electropolished metallic Cu with a predominant (100) surface and compared it to native oxide-covered Cu. The electropolished Cu surface rapidly oxidized after exposure to either air or electrolyte solutions. However, this oxide was reduced below 0.1 V vs. RHE, thus returning to the metallic Cu before NO3RR. It was distinguished from the native oxide on Cu, which remained during NO3RR. Fast NO3- and NO reduction on the metallic Cu delivered 91.5 ± 3.7% faradaic efficiency for NH3 at -0.4 V vs. RHE. In contrast, the native oxide on Cu formed undesired products and low NH3 yield. Operando shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS) analysis revealed the adsorbed NO3-, NO2, and NO species on the electropolished Cu as the intermediates of NH3. Low overpotential NO3- and NO adsorptions and favorable NO reduction are key to increased NH3 productivity over Cu samples, which was consistent with the DFT calculation on Cu(100).
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Commercial bacterial exopolysaccharide (EPS) applications have been gaining interest; therefore, strains that provide higher yields are required for industrial-scale processes. Succinoglycan (SG) is a type of bacterial anionic exopolysaccharide produced by Rhizobium, Agrobacterium, and other soil bacterial species. SG has been widely used as a pharmaceutical, cosmetic, and food additive based on its properties as a thickener, texture enhancer, emulsifier, stabilizer, and gelling agent. An SG-overproducing mutant strain (SMC1) was developed from Sinorhizobium meliloti 1021 through N-methyl-N'-nitro-N-nitrosoguanidine (NTG) mutation, and the physicochemical and rheological properties of SMC1-SG were analyzed. SMC1 produced (22.3 g/L) 3.65-fold more SG than did the wild type. Succinoglycan (SMC1-SG) overproduced by SMC1 was structurally characterized by FT-IR and 1H NMR spectroscopy. The molecular weights of SG and SMC1-SG were 4.20 × 105 and 4.80 × 105 Da, respectively, as determined by GPC. Based on DSC and TGA, SMC1-SG exhibited a higher endothermic peak (90.9 °C) than that of SG (77.2 °C). Storage modulus (G') and loss modulus (Gâ³) measurements during heating and cooling showed that SMC1-SG had improved thermal behavior compared to that of SG, with intersections at 74.9 °C and 72.0 °C, respectively. The SMC1-SG's viscosity reduction pattern was maintained even at high temperatures (65 °C). Gelation by metal cations was observed in Fe3+ and Cr3+ solutions for both SG and SMC1-SG. Antibacterial activities of SG and SMC1-SG against Escherichia coli and Staphylococcus aureus were also observed. Therefore, like SG, SMC1-SG may be a potential biomaterial for pharmaceutical, cosmetic, and food industries.
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Recently, polymer-based tissue adhesives (TAs) have gained the attention of scientists and industries as alternatives to sutures for sealing and closing wounds or incisions because of their ease of use, low cost, minimal tissue damage, and short application time. However, poor mechanical properties and weak adhesion strength limit the application of TAs, although numerous studies have attempted to develop new TAs with enhanced performance. Therefore, next-generation TAs with improved multifunctional properties are required. In this review, we address the requirements of polymeric TAs, adhesive characteristics, adhesion strength assessment methods, adhesion mechanisms, applications, advantages and disadvantages, and commercial products of polysaccharide (PS)-based TAs, including chitosan (CS), alginate (AL), dextran (DE), and hyaluronic acid (HA). Additionally, future perspectives are discussed.
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Quitosana , Adesivos Teciduais , Polissacarídeos , Polímeros , Alginatos , AdesivosRESUMO
BACKGROUND: Inflammasomes recognize endogenous and exogenous danger signals, and subsequently induce the secretion of IL-1ß. Studying inflammasomes in the red fox (Vulpes vulpes) is crucial for wildlife veterinary medicine, as it can help control inflammatory diseases in foxes. METHODS: We investigated the activation and intracellular mechanisms of three inflammasomes (NLRP3, AIM2, and NLRC4) in fox peripheral blood mononuclear cells (PBMCs), using established triggers and inhibitors derived from humans and mice. RESULTS: Fox PBMCs exhibited normal activation and induction of IL-1ß secretion in response to representative inflammasome triggers (ATP and nigericin for NLRP3, dsDNA for AIM2, flagellin for NLRC4). Additionally, PBMCs showed normal IL-1ß secretion when inoculated with inflammasome-activating bacteria. In inhibitors of the inflammasome signaling pathway, fox inflammasome activation was compared with mouse inflammasomes. MCC950, a selective NLRP3 inhibitor, suppressed the secretion of dsDNA- and flagellin-mediated IL-1ß in foxes, unlike mice. CONCLUSIONS: These findings suggest that NLRP3 may have a common role in dsDNA- and flagellin-mediated inflammasome activation in the red fox. It implies that this fox inflammasome biology can be applied to the treatment of inflammasome-mediated diseases in the red fox.