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Efficient and reliable technologies for the on-site detection of illicit drugs are important in drug-facilitated crime investigations. However, the development of such technologies is challenging. Based on the synthetic optimization, introducing a boron ester functional group to the two furanic indicators endows the stimulus-responsive properties synergistically. The ring-opening reaction of the indicators in the presence of amine-containing illicit drugs generated well-known donor-acceptor Stenhouse adducts, accompanied by strong color changes. A small-size and lightweight laminated sensor was integrated based on the outstanding ratiometric variations of the two active furanic indicators. A prototype platform was fabricated equipped with a circuit control, a mini pump, and a signal processing system. A user-friendly detection and efficient screening of amine-containing illicit drugs, including phenethylamines, amphetamines, cathinones, and tryptamines in the liquid states were conducted. The ratiometric response of the sensor was linear in the concentration range of 2.1-10.6 µg·mL-1 for methamphetamine·HCl and methcathinone ·HCl. The detection limits for the two illicit drugs at the sublevel (ng·mL-1) were found to be 8.4 and 9.0 ng·mL-1, respectively. Double-blind field tests and different illicit drugs were evaluated with good screening capability. Successful trials showed the potential applications of the developed prototype platform for efficient and on-site analytical determination.
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C-reactive protein (CRP) is an acute-phase protein produced by the liver in response to infection and during chronic inflammatory disorders. Systemic inflammation is a major driver of cirrhosis progression from the compensated to the decompensated stage. Previous studies have shown that pentameric CRP (pCRP) to be a weak predictor of disease severity and prognosis in patients with decompensated hepatitis B cirrhosis, with it being only helpful for identifying patients with a higher short-term risk of death under certain conditions. Accumulating evidence indicates that pCRP dissociates to and acts primarily as the monomeric conformation (mCRP) at inflammatory loci, suggesting that mCRP may be a potentially superior disease marker with higher specificity and relevance to pathogenesis. However, it is unknown whether mCRP and anti-mCRP autoantibodies are associated with disease severity, or progression in decompensated hepatitis B cirrhosis. In this study, we evaluated the serum levels of mCRP and anti-mCRP autoantibodies in patients with decompensated cirrhosis of hepatitis B and their association with disease severity and theoretical prognosis. The results showed that patients with high mCRP and anti-mCRP autoantibody levels had more severe liver damage and that coagulation function was worse in patients with high anti-mCRP autoantibodies. Analysis of the correlation between pCRP, mCRP and anti-mCRP autoantibody levels with Model for End-Stage Liver Disease (MELD), Albumin-Bilirubin (ALBI), and Child-Turcotte-Pugh (CTP) prognostic scores showed that mCRP was the most strongly correlated with MELD score, followed by anti-mCRP autoantibodies; conversely, pCRP was not significantly correlated with prognostic score. Therefore, mCRP and anti-mCRP autoantibodies may be more advantageous clinical indicators than pCRP for evaluating the pathological state of decompensated hepatitis B cirrhosis.
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Autoanticorpos , Biomarcadores , Proteína C-Reativa , Cirrose Hepática , Índice de Gravidade de Doença , Humanos , Proteína C-Reativa/análise , Proteína C-Reativa/metabolismo , Feminino , Prognóstico , Masculino , Cirrose Hepática/imunologia , Cirrose Hepática/diagnóstico , Cirrose Hepática/sangue , Cirrose Hepática/etiologia , Autoanticorpos/sangue , Autoanticorpos/imunologia , Pessoa de Meia-Idade , Biomarcadores/sangue , Adulto , Progressão da Doença , Hepatite B/imunologia , Hepatite B/sangueRESUMO
Polynitrogen has been widely studied recently as a rising star of high energy density materials. Here, we performed a systematic study of the Zr-N compounds in the N-rich region by the first-principles method. The high-pressure phase diagram of the Zr-N system is enriched by proposing five new compounds. ZrN10 with the infinitely extended band shaped structure is first reported. The band-like polynitrogen of ZrN10 decomposes into a more stable chain-like polynitrogen structure under the influence of temperature. Additionally, the novel honeycomb-like band-shaped N10 structure hcb-N10 has been discovered by removing the Zr atoms. The absence of the -4 oxidation state in the N10 unit prompts its further polymerization, which makes hcb-N10 possess dynamical and thermal stability in ambient conditions. hcb-N10 is a semiconductor with a bandgap of 2.97 eV due to highly localized electrons. Both chain-ZrN10 and hcb-N10 represent potential candidates for HEDMs with outstanding energy and explosive performance.
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Objective: The purpose of this review is to identify the impact of virtual reality (VR) technology on student engagement, specifically cognitive engagement, behavioral engagement, and affective engagement. Methods: A comprehensive search of databases such as Google, Scopus, and Elsevier was conducted to identify English-language articles related to VR and classroom engagement for the period from 2014 to 2023. After systematic screening, 33 articles were finally reviewed. Results: The use of VR in the classroom is expected to improve student engagement and learning outcomes, and is particularly effective for students with learning disabilities. However, introducing VR into middle school education poses several challenges, including difficulties in the education system to keep up with VR developments, increased demands on students' digital literacy, and insufficient proficiency of teachers in using VR. Conclusion: To effectively utilize VR to increase student engagement, we advocate for educational policymakers to provide training and technical support to teachers to ensure that they can fully master and integrate VR to increase student engagement and instructional effectiveness.
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Carbon nanomembranes (CNMs), with a high density of subnanometer channels, enable superior salt separation performance compared to conventional membranes. However, defects that occur during the synthesis and transfer processes impede their technical realization on a macroscopic scale. Here, we introduce a practical and scalable interfacial polymerization method to effectively heal defects while preserving the subnanometer pores within CNMs. The defect-healed freestanding CNMs show an exceptional performance in forward osmosis (FO), achieving a water flux of 105 L m-2 h-1 and a specific reverse salt flux of 0.1 g L-1 when measured with 1 M NaCl as draw solution. This water flux is 10 times higher than that of commercially available FO membranes, and the reverse salt flux is 70% lower. Through successful implementation of the defect-healing method and support optimization, we demonstrate the synthesis of fully functional, centimeter-scale CNM-based composite membranes showing high water permeance and a high salt rejection. Our defect-healing method presents a promising pathway to overcome limitations in CNM synthesis, advancing their potential for practical salt separation applications.
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BACKGROUND: Gut microbiota exert an immense effect on host health and host environmental adaptation. Furthermore, the composition and structure of gut microbiota are determined by the environment and host genetic factors. However, the relative contribution of the environment and host genetic factors toward shaping the structure of gut microbiota has been poorly understood. METHODS: In this study, we characterized the fecal microbial communities of the closely related voles Neodon fuscus, Lasiopodomys brandtii, and L. mandarinus after caged feeding in the laboratory for 6 months, through high-throughput sequencing and bioinformatics analysis. RESULTS: The results of pairwise comparisons of N. fuscus vs. L. brandtii and L. mandarinus vs. L. brandtii revealed significant differences in bacterial diversity and composition after domestication. While 991 same operational taxonomic units (OTUs) were shared in three voles, there were 362, 291, and 303 species-specific OTUs in N. fuscus, L. brandtii, and L. mandarinus, respectively. The relative abundances of Proteobacteria and Prevotella, which are reported to be enriched in high-altitude populations, were significantly higher in high-altitude N. fuscus than in low-altitude L. brandtii after domestication. Firmicutes, which produce various digestive enzymes for energy metabolism, and Spirochaetes, which can degrade cellulose, were found in higher abundance in subterranean L. mandarinus than that in L. brandtii which dwells on the earth surface. CONCLUSION: Our findings showed that some components of gut microbiota still maintained dominance even when different host species are reared under the same environmental conditions, suggesting that these bacteria are substantially influenced by host factors.
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Arvicolinae , Microbioma Gastrointestinal , Animais , Arvicolinae/microbiologia , Fezes/microbiologia , Especificidade da EspécieRESUMO
Carrageenan (CGN) is a typical sulfated polysaccharide widely applied in the food and pharmaceutical industries. Its in vivo behavior plays vital roles in understanding structural and biological functional relationships. The lack of UV chromophores in highly sulfated polysaccharides presents a challenge for their in vivo behavior studies. Therefore, this study aimed to develop a fast and effective quantitative fluorescence method for investigating the pharmacokinetics and tissue distribution of CGN. Fluorescence isothiocyanate labeling of CGN (FCGN) and microplate reader-based measurements were developed and validated to study its pharmacokinetics. These results showed that the FCGN concentration peaked at 3 h, the mean residence time was 36.6 h, and the clearance rate was 0.1 L/h/kg. Most of the FCGN was excreted in the feces, while 9.2 % was excreted in the urine, suggesting absorption and metabolism. The pharmacokinetic parameters indicated that the FCGN was absorbed quickly, eliminated slowly, and could remain in the body for a sustained profile. Moreover, ex vivo imaging and quantification of FCGN in tissues revealed that FCGN accumulated in the liver and kidney. Furthermore, oral administration of CGN or KOs for 14 days led to changes in liver and kidney indices. Histological analysis of significant organs revealed hepatocyte necrosis in the liver, renal tubular vacuolization in the kidney, and incomplete colonic epithelial cells. The KOs had a more significant effect on inflammatory cell infiltration than did CGNs. These in vivo findings laid the foundation for the study and application of CGN in food and pharmaceutical applications.
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Carragenina , Animais , Camundongos , Distribuição Tecidual , Administração Oral , Masculino , Fígado/metabolismo , Fígado/efeitos dos fármacos , Rim/efeitos dos fármacos , Rim/metabolismoRESUMO
Background: The main purpose of this study is to analyze the relationship between moral sensitivity, empathy, and caring behaviors and to explore the mediating effect of empathy on moral sensitivity and caring behaviors of nursing interns. Methods: A cross-sectional survey was conducted from August to September 2022 in which 261 nursing interns from two Grade 3A Hospitals in Xi'an participated. The questionnaires used in the survey include the General Information Questionnaire (GIQ), the Moral Sensitivity Questionnaire-Revised Version translated into Chinese (MSQ R-CV), the Chinese version of the Jefferson Empathy Scale (JSE), and the Chinese version of the Caring Behavior Inventory (C-CBI). The obtained data were analyzed through descriptive statistics, a one-way analysis of variance (ANOVA), and Pearson's correlation coefficient, and the mediating effect of empathy was tested through structural equations. Results: The overall mean of moral sensitivity of nursing interns in two Grade 3A Hospitals in Xi'an is 40.84 ± 8.73, the overall mean of empathy is 100.51 ± 21.56, and the overall mean of caring behavior is (113.81 ± 21.05). Statistical analysis showed that there is a positive correlation between moral sensitivity and caring behavior of nursing interns (r = 0.376, p < 0.01), between their empathy and moral sensitivity (r = 0.336, p < 0.01), and between their empathy and caring behavior (r = 0.394, p < 0.01). The empathy of nursing interns has a mediated effect on the relationship between moral sensitivity and caring behavior. The mediated effect value was 0.14, accounting for 31.82% of the total effect. Conclusion: The moral sensitivity of nursing interns can have a direct impact on predicting the caring behavior and indirect influences their caring behaviors mediated by empathy, with the latter effect being mediated by empathy. Therefore, nursing educators and hospital administrators should adopt targeted interventions to improve the moral sensitivity and empathy of nursing interns, which can further prove to be beneficial in improving their caring behaviors, leading to enhanced quality of nursing care and reduced nurse-patient conflicts and finally to a stabilized nursing team.
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Empatia , Princípios Morais , Humanos , Estudos Transversais , Análise de Variância , Inquéritos e QuestionáriosRESUMO
BACKGROUND: Screening and developing novel antifungal agents with minimal environmental impact are needed to maintain and increase crop production, which is constantly threatened by various pathogens. Small peptides with antimicrobial and antifungal activities have been known to play an important role in plant defense both at the pathogen level by suppressing its growth and proliferation as well as at the host level through activation or priming of the plant's immune system for a faster, more robust response against fungi. Rust fungi (Pucciniales) are plant pathogens that can infect key crops and overcome resistance genes introduced in elite wheat cultivars. RESULTS: We performed an in vitro screening of 18 peptides predominantly of plant origin with antifungal or antimicrobial activity for their ability to inhibit leaf rust (Puccinia triticina, CCDS-96-14-1 isolate) urediniospore germination. Nine peptides demonstrated significant fungicidal properties compared to the control. Foliar application of the top three candidates, ß-purothionin, Purothionin-α2 and Defensin-2, decreased the severity of leaf rust infection in wheat (Triticum aestivum L.) seedlings. Additionally, increased pathogen resistance was paralleled by elevated expression of defense-related genes. CONCLUSIONS: Identified antifungal peptides could potentially be engineered in the wheat genome to provide an alternative source of genetic resistance to leaf rust.
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PURPOSE: Pancreatic cancer (PC) is a highly malignant tumor that poses a severe threat to human health. Brain glycogen phosphorylase (PYGB) breaks down glycogen and provides an energy source for tumor cells. Although PYGB has been reported in several tumors, its role in PC remains unclear. METHODS: We constructed a risk diagnostic model of PC-related genes by WGCNA and LASSO regression and found PYGB, an essential gene in PC. Then, we explored the pro-carcinogenic role of PYGB in PC by in vivo and in vitro experiments. RESULTS: We found that PYGB, SCL2A1, and SLC16A3 had a significant effect on the diagnosis and prognosis of PC, but PYGB had the most significant effect on the prognosis. Pan-cancer analysis showed that PYGB was highly expressed in most of the tumors but had the highest correlation with PC. In TCGA and GEO databases, we found that PYGB was highly expressed in PC tissues and correlated with PC's prognostic and pathological features. Through in vivo and in vitro experiments, we found that high expression of PYGB promoted the proliferation, invasion, and metastasis of PC cells. Through enrichment analysis, we found that PYGB is associated with several key cell biological processes and signaling pathways. In experiments, we validated that the MAPK/ERK pathway is involved in the pro-tumorigenic mechanism of PYGB in PC. CONCLUSION: Our results suggest that PYGB promotes PC cell proliferation, invasion, and metastasis, leading to poor patient prognosis. PYGB gene may be a novel diagnostic biomarker and gene therapy target for PC.
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Neoplasias Pancreáticas , Humanos , Biomarcadores , Glicogênio Fosforilase Encefálica/genética , Glicogênio Fosforilase Encefálica/metabolismo , Sistema de Sinalização das MAP Quinases/genética , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/terapia , Prognóstico , Transdução de Sinais/genéticaRESUMO
Four high-pressure N-rich compounds (Pmn21-CeN7, Amm2-CeN9, P1Ì-CeN10, and P1Ì-II-CeN10) are proposed using first-principles calculations. Novel polymeric units (a heart shaped layered structure, chain-like N8 rings, and two new banded structures) in four cerium nitrides are reported for the first time in this study. The analyses of electronic structures and bonding properties show that the charge transfer between Ce and N atoms promotes the formation of the Ce-N ionic bond and N-N covalent bond, which play an important role in stabilizing the nitrogen skeleton. Four new phases possess high energy densities (3.24-3.86 kJ g-1), indicating that they are favorable high-energy density materials. Moreover, P1Ì-CeN10 possesses ultra-incompressibility along the [1 0 0] direction. Finally, infrared and Raman spectra are analyzed to provide guidance for experimental synthesis.
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Pancreatic adenocarcinoma (PAAD) is a frequent malignant tumor in the pancreas. The incomplete understanding of cancer etiology and pathogenesis, as well as the limitations in early detection and diagnostic methods, have created an urgent need for the discovery of new therapeutic targets and drugs to control this disease. As a result, the current therapeutic options are limited. In this study, the weighted gene co-expression network analysis (WGCNA) method was employed to identify key genes associated with the progression and prognosis of pancreatic adenocarcinoma (PAAD) patients in the Gene Expression Profiling Interactive Analysis (GEPIA) database. To identify small molecule drugs with potential in the treatment of pancreatic adenocarcinoma (PAAD), we compared key genes to the reference dataset in the CMAP database. First, we analyzed the antitumor properties of small molecule drugs using cell counting kit-8 (CCK-8), AO/EB and Transwell assays. Subsequently, we integrated network pharmacology with molecular docking to explore the potential mechanisms of the identified molecules' anti-tumor effects. Our findings indicated that the progression and prognosis of PAAD patients in pancreatic cancer were associated with 11 genes, namely, DKK1, S100A2, CDA, KRT6A, ITGA3, GPR87, IL20RB, ZBED2, PMEPA1, CST6, and MUC16. These genes were filtered based on their therapeutic potential through comparing them with the reference dataset in the CMAP database. Taxifolin, a natural small molecule drug with the potential for treating PAAD, was screened by comparing it with the reference dataset in the CMAP database. Cell-based experiments have validated the potential of Taxifolin to facilitate apoptosis in pancreatic cancer cells while restraining their invasion and metastasis. This outcome is believed to be achieved via the HIF-1 signaling pathway. In conclusion, this study provided a theoretical basis for screening genes related to the progression of pancreatic cancer and discovered potentially active small molecule drugs. The experimental results confirm that Taxifolin has the ability to promote apoptosis in pancreatic cancer cells.
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Adenocarcinoma , Neoplasias Pancreáticas , Quercetina/análogos & derivados , Humanos , Detecção Precoce de Câncer , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/genética , Simulação de Acoplamento Molecular , Pâncreas , Perfilação da Expressão Gênica , Apoptose/genética , Prognóstico , Regulação Neoplásica da Expressão Gênica , Proteínas de Membrana , Receptores de Ácidos LisofosfatídicosRESUMO
The increasing automobile repair industries (ARIs) with spray facilities have become an important volatile organic compound (VOC) pollution source in China. However, the VOC health risk assessment for long-term exposure in ARIs has not been well characterized. In this study, though sampled VOCs from 51 typical ARIs in Beijing, the relationship between emission patterns, average daily exposure concentrations (EC), and health risks was comprehensively analyzed with the health assessment method. Results showed that concentrations of 117 VOCs from the samples ranged from 68.53 to 19863.32 µg·m-3, while the ARI operator's daily VOC inhalation EC was 11.24-1460.70 µg·m-3. The organic VOC (OVOC) concentration accounted for 73.16 ~ 94.52% in the solvent-based paint workshops, while aromatics were the main VOC component in water-based paint spraying (WPS) workshops, accounting for 70.08%, respectively. And the method of inhalation exposure health risk assessment was firstly used to evaluate carcinogenicity and non-carcinogenicity risk for sprayers in ARIs. The cumulative lifetime carcinogenic risk (LCR) for 24 sampled VOCs were within acceptable ranges, while the mean hazard index (HI) for 1 year with 44 sampled VOCs was over 1. Among them, ethyl alcohol had a high carcinogenic risk in both mixed water-based paint (MP) and solvent-based paint workshops. The mean HI associated with aromatics were 2.88E - 3 and 4.30E - 3 for 1 h in MP and WPS workshops. O-ethyl toluene and acetone are VOC components that need to be paid attention to in future paint raw materials and spraying operations. Our study will provide the important references for the standard of VOC occupational exposure health limits in ARIs.
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Poluentes Atmosféricos , Compostos Orgânicos Voláteis , Compostos Orgânicos Voláteis/análise , Poluentes Atmosféricos/análise , Automóveis , Monitoramento Ambiental , Solventes , Água , ChinaRESUMO
The catalytic hydrogenation of biomass-derived chemicals is essential in chemical industry due to the growing demand for sustainable and renewable energy sources. In this study, we present a comprehensive theoretical investigation regarding the hydrogenation of glycolaldehyde to ethylene glycol over a Ru/C catalyst by employing density functional theory and ab initio molecular dynamics simulations. With inclusion of explicit solvation, we have demonstrated that the glycolaldehyde hydrogenation is significantly improved due to the fast proton transfer through the hydrogen bond network. The enhanced activity could be attributed to the participation of the solvent water as the hydrogen source and the highly positively charged state of a Ru cluster in an aqueous phase, which are critical for the activation of aldehyde groups and proton-assisted hydrogenation. Overall, our findings provide valuable insights into glycolaldehyde hydrogenation over Ru/C catalysts in the aqueous phase, highlighting the importance of solvation effects in the biomass conversion.
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Polysaccharides have unique physio-chemical properties and various biological functions and have rapidly expanded interest over the last two decades. The purification of polysaccharides and their degraded oligosaccharides is challenging because carbohydrates have no chromophore and need a proper detector to monitor the chromatographic elution process. This study proposed an active derivatization detection (ADD) method based on active splitting from post-column flow, a microchannel reactor for efficient derivatization of polysaccharide reducing sugars with p-hydroxybenzoic acid hydrazide, and in-line detection by the UV detector of liquid chromatography system. The method and device were validated by the use of 11 monosaccharides, sulfated oligosaccharides (from degraded carrageenan), and polysaccharides (from Zizania latifolia). It has shown much better performance than the traditional phenol-sulfuric acid method (gold standard). Moreover, the ADD module presumes an add-in to the original preparative LC system, independent of the scale of the purification process and type of system. The developed method is versatile for chromatographic separation of carbohydrates and lays the foundation for their subsequent studies.
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Carboidratos , Oligossacarídeos , Cromatografia Líquida de Alta Pressão/métodos , Carboidratos/análise , Cromatografia Líquida , Oligossacarídeos/química , Polissacarídeos/químicaRESUMO
Purpose: To investigate the intestinal inflammatory response and the abundance of intestinal bacteria in rats with high-fat diet (HFD)-induced nonalcoholic fatty liver disease (NAFLD) and assess the intervention effects of taurine (TAU). Methods: Forty male Sprague-Dawley rats were randomly divided into five groups: group I, normal diet and normal saline gavage; group II, normal diet and TAU gavage; group III, HFD and normal saline gavage; group IV, HFD and TAU gavage (from the 1st week); group V, HFD and TAU gavage (from the 10th week). At the end of the 16th week, all the animals were sacrificed. Body weight, liver weight, liver function, and serum lipid levels were measured. The histopathologies of the liver and ileum were observed. The mRNA and protein expression levels of interleukin 17 (IL-17) and IL-10 in the ileum were detected by reverse transcription quantitative polymerase chain reaction (qPCR) and immunohistochemistry. Three types of bacteria were detected in intestinal feces using the 16S rDNA qPCR method. Results: The ileal IL-17 level in group III was significantly higher than those in the other four groups (P < 0.01). The ileal IL-10 mRNA levels in group IV was significantly higher than those in groups III and V (P < 0.05), and IL-10 protein MOD levels in group III was significantly lower than those in the other four groups (P < 0.01). The numbers of Lactobacillus in group III were significantly lower than those in the other four groups (P < 0.01 or P < 0.05). The numbers of Bifidobacteria in groups IV and V were significantly increased compared with that in group III (P < 0.05). Conclusion: TAU may down-regulate the expression of IL-17, up-regulate the expression of IL-10 and regulate the intestinal flora, and alleviate the liver and intestinal damage in rats with HFD-induced NAFLD.
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The swollen culm (also known as Jiaobai) of Zizania latifolia is formed by the smut Ustilago esculenta invades the Z. latifolia. The new tissue formed due to the symbiotic relationship has entices the attention of researchers to study its polysaccharide structure along with biological evaluation. Five fractions of polysaccharides were obtained owing to hot water extraction, alcoholic precipitation, and chromatographic purification. Bioactivity assays showed that ZLPs have good antioxidant, hypoglycemic activities and protective activity against oxidative damage. The ZLP-1 and ZLP-2 were determined to be neutral polysaccharides with high purity, exhibiting propitious bioactivity, consequently they were subjected to indispensable structural characterization. These results showed that ZLP-1 has molecular weight (Mw) of 103 kDa and glucose (Glc) (76.68 %) as the primary monosaccharide; the ZLP-2 has Mw of 122 kDa and galactose (Gal) (41.04 %) and arabinose (Ara) (27.12 %). Structural elucidation by methylation and nuclear magnetic resonance (NMR) analysis suggested ZLP-1 is a glucan, with â3)-ß-Glcp-(1â3)-ß-Glcp-(1â4)-ß-Glcp-(1â4)-ß-Glcp-(1â3,6)-ß-Galp-(1â3)-ß-Glcp-(1â as the mainchain and the terminal Araf and Glcp; the ZLP-2 is a Galactoxylan, with â3,4)-ß-xylp-(1â3)-ß-Galp-(1â3,6)-ß-Galp-(1â3,6)-ß-Galp-(1â as the mainchain and the terminal Araf and Glcp. The structural arrangements provide a chemical basis for understanding the nutritional and pharmacological activities of polysaccharides from Zizania latifolia.
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Glucanos , Polissacarídeos , Polissacarídeos/química , Monossacarídeos/análise , Antioxidantes/química , GalactoseRESUMO
Despite the prodigious potential of lithium-sulfur (Li-S) batteries as future rechargeable electrochemical systems, their commercial implementation is hindered by several vital issues, including the shuttle effect and sluggish migration of lithium-polysulfides leading to rapid capacity fading. Here, we systematically investigate the potential of first-row two-dimensional transition metal carbides (TMCs) as sulfur cathodes for Li-S batteries. The adsorption strength of lithium-polysulfides on TMCs is induced by the amount of charge transfer from the former to the latter and the proposed periodic relationship between sulfur in Li2S and 3d-transition metals. Our findings show that the VC nanosheet possesses immense anchoring potential and exhibits a comparatively low migration energy barrier for lithium-ion and Li2S molecules. Additionally, we report ab initio molecular dynamics simulations for lithiated polysulfide species anchored on a TMC-based model with a liquid-electrolyte medium. The microscopic reaction mechanism, revealed by the evolution of the reaction voltage during lithiation, demonstrates that the dissolution of high-order lithium-polysulfides in the electrolytes can be prevented due to their robust interaction with TMC-based cathode materials. These appealing features suggest that TMCs present colossal performance improvements for anchoring lithium-polysulfides, stimulating the active design of sulfur cathodes for practical Li-S batteries.
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Unlike the known aggregation-caused quenching (ACQ) that the enhancement of π-π interactions in rigid organic molecules usually decreases the luminescent emission, here we show that an intermolecular "head-to-head" π-π interaction in the phenanthrene crystal, forming the so-called "transannular effect", could result in a higher degree of electron delocalization and thus photoluminescent emission enhancement. Such a transannular effect is molecular configuration and stacking dependent, which is absent in the isomers of phenanthrene but can be realized again in the designed phenanthrene-based cocrystals. The transannular effect becomes more significant upon compression and causes anomalous piezoluminescent enhancement in the crystals. Our findings thus provide new insights into the effects of π-π interactions on luminescence emission and also offer new pathways for designing efficient aggregation-induced emission (AIE) materials to advance their applications.