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Liver cancer is one of the most lethal gastrointestinal malignancies. Emerging evidence has underscored the pivotal role of long non-coding RNAs (lncRNAs) in tumorigenesis, with ST8SIA6-AS1 identified as a novel oncogenic lncRNA contributing to liver cancer progression. ST8SIA6-AS1 is consistently upregulated in hepatic cancer tissues and is strongly associated with unfavorable prognosis. Moreover, it demonstrates high diagnostic efficacy in detecting HCC. ST8SIA6-AS1 is involved in various cellular processes including proliferation, migration, and invasion, primarily through its function as a competing endogenous RNA (ceRNA), thereby facilitating hepatocarcinogenesis and disease advancement. This review provides a detailed examination of the molecular functions and regulatory mechanisms of ST8SIA6-AS1 in hepatocellular carcinoma (HCC) and highlights its potential as a promising biomarker for liver cancer, aiming to propel the development of innovative therapeutic strategies for HCC management.
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The experiment aimed to investigate the effects of plant polysaccharides combined with boric acid on digestive function, immune function and harmful gas and heavy metal contents in the faeces of fatteners. For this study, 90 healthy crossbred fatteners were selected and randomly divided into five groups: the control group was fed with a basal diet (Con); experimental group I was fed with basal diet + 40 mg/kg boric acid (BA); experimental group II was fed with basal diet + 40 mg/kg boric acid + 400 mg/kg Astragalus polysaccharides (BA+APS); experimental group III was fed with basal diet + 40 mg/kg boric acid + 200 mg/kg Ganoderma lucidum polysaccharides (BA+GLP); and experimental group IV was fed with basal diet + 40 mg/kg boric acid + 500 mg/kg Echinacea polysaccharides (BA+EPS). Compared with Con, the average daily gain (ADG), the trypsin activities in the duodenum and jejunum, the IL-2 levels in the spleen, the T-AOC activities and GSH-Px contents in the lymph node of fattening were increased in the BA group (p < 0.05), but malondialdehyde content in the lymph and spleen, and the contents of NH3, H2S, Hg, Cu, Fe and Zn in the feces and urine were decreased (p < 0.05). Compared with the BA, the ADG, gain-to-feed ratio (G/F), the trypsin and maltase activities in the duodenum and jejunum were increased in the BA+APS (p < 0.05), and the T-SOD activities in the spleen and T-AOC activities in the lymph node were also increased (p < 0.05), but the H2S level was decreased in the feces and urine (p < 0.05). Compared with the BA, the ADG, G/F and the trypsin and maltase activities in the duodenum were increased in the BA+GLP and BA+EPS (p < 0.05), the activities of maltase and lipase in the duodenum of fatteners in the BA+GLP and the activities of trypsin, maltase and lipase in the BA+EPS were increased (p < 0.05). Gathering everything together, our findings reveal that the combined addition of boric acid and plant polysaccharides in the diet of fatteners synergistically improved their growth performance and immune status. That may be achieved by regulating the activity of intestinal digestive enzymes, improving the antioxidant function and then promoting the digestion and absorption of nutrients. Furthermore, the above results reduce the emission of harmful gases and heavy metals in feces and urine.
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Bordetella bronchiseptica is a significant contributor to respiratory disease in pigs, leading to substantial economic losses in the swine industry worldwide. We isolated 52 B. bronchiseptica strains from 542 samples collected from pigs with atrophic rhinitis and bronchopneumonia in central China. Multi-locus sequence typing identified two prevalent sequence types: ST6 (69.23%) and ST7 (30.77%). PCR-based detection of seven virulence genes (fhaB, prn, cyaA, dnt, bteA, fla, and bfrZ) revealed that six of these genes were present in over 90% of the isolates, with bfrZ being the exception at 59.62%. Antimicrobial susceptibility testing, performed using the K-B method, demonstrated high sensitivity to enrofloxacin, polymyxin, and doxycycline but a notable resistance to tylosin, trimethoprim, tobramycin, ciprofloxacin, and amikacin. Remarkably, 86.54% of the isolates exhibited a multidrug-resistant phenotype. Notably, we successfully screened a strain of B. bronchiseptica with a heteroresistance phenotype to gentamicin using population analysis profiling, which is a rare case. Biofilm-formation assays indicated that 96.15% of the isolates possessed biofilm-forming capabilities. These findings provide crucial insights into the prevalence of B. bronchiseptica in central China, facilitating the development of effective preventive measures to safeguard both animal and human health.
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Authenticating whole wheat foods poses a significant challenge for both the grain industry and consumers. Alkylresorcinols (ARs), serving as biomarkers of whole wheat, play a crucial role in assessing the authenticity of whole wheat foods. Herein, we introduce a novel molecularly imprinted electrochemical sensor with modifications involving a molecularly imprinted polymer (MIP) and MXene nanosheets, enabling highly sensitive and selective detection of ARs. Notably, we specifically chose 5-heneicosylresorcinol (AR21), the predominant homologue in whole wheat, as the template molecule. α-Cyclodextrin and acrylamide served as dual functional monomers, establishing a robust multiple interaction between the MIP and AR21. As a result, the sensor exhibited a wide linear range of 0.005 to 100 µg·mL-1 and a low detection limit of 2.52 ng·mL-1, demonstrating exceptional selectivity and stability. When applied to commercial whole wheat foods, the assay achieved satisfactory recoveries and accuracy, strongly validating the practicality and effectiveness of this analytical technique.
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Técnicas Eletroquímicas , Contaminação de Alimentos , Impressão Molecular , Resorcinóis , Triticum , alfa-Ciclodextrinas , Resorcinóis/química , Resorcinóis/análise , Triticum/química , alfa-Ciclodextrinas/química , Técnicas Eletroquímicas/métodos , Técnicas Eletroquímicas/instrumentação , Contaminação de Alimentos/análise , Limite de DetecçãoRESUMO
Phenolic acids can be encapsulated by starch electrospun fibers, and the structural and functional properties of the electrospun fiber are affected by the chemical structure of phenolic acid. In this study, five phenolic acids (protocatechuic acid (PA), p-hydroxybenzoic acid (PHBA), p-coumaric acid (PCA), ferulic acid (FA), and caffeic acid (CA)) were chosen to prepare electrospun fibers with high amylose corn starch (HACS) at different voltages. Morphology and complexation efficiency results revealed that the electrospun fibers prepared at 21.0 kV were smooth and continuous with high encapsulation efficiency (EE) and loading efficiency (LE). The chemical structure of phenolic acid played an important role in the structure and properties of electrospun fibers by influencing the complexation of HACS with phenolic acids and the inhibitory effect of amylase. As a result, electrospun fibers containing HACS-CA inclusion complex had higher relative crystallinity (25.47 %), higher thermal degradation temperatures (356.17 °C), and the strongest resistance to digestion (starch digestive ratio = 22.98 %). It is evident that electrospun fibers containing HACS-phenolic acid inclusion complexes not only achieve high phenolic acid complexation efficiency, but also resist the effects of the gastric and small intestinal environment on phenolic acids, thereby improving the bioaccessibility of phenolic acids.
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Amido , Zea mays , Amido/química , Zea mays/química , Amilose/química , HidroxibenzoatosRESUMO
Boron is one of the essential trace elements in animals. Although boron supplementation can enhance immune function and promote cell proliferation, high-dose boron supplementation can negatively affect immune function and inhibit cell proliferation. Furthermore, its action pathway is unknown. In this study, ERK1/2, JNK, and p38MAPK signaling pathways were blocked using specific blockers to investigate the impact of low-dose and high-dose boron on proliferation, apoptosis, and immune function of lymphocytes, and the expression of genes related to cell proliferation and apoptosis in rats. The addition of 0.4 mmol/L boron did not affect the ratio of CD4+/CD8+ T cells (P>0.05), IgG and IFN-γ contents (P>0.05), the proliferation rate of lymphocytes (P>0.05), and mRNA and protein expressions of PCNA (P>0.05) in the spleen after ERK1/2 signal pathway was selectively inhibited. Moreover, the addition of 40 mmol/L boron did not affect the proportion of CD4+ T cells, contents of IgG and cytokines (IL-2 and IL-4), proliferation and apoptosis rates of lymphocytes, and expression of proliferation- and apoptosis-related genes in the spleen. Meanwhile, the addition of 0.4 mmol/l boron increased the ratio of CD4+/CD8+ T cells (P<0.05 or P<0.01), IFN-γ or IgG contents (P<0.05), and the proliferation rate of lymphocytes (P<0.05) in spleen after selective inhibition of JNK or p38MAPK signaling pathways, while the protein expression of Caspase-3 decreased (P<0.05 or P<0.01). Furthermore, 40 mmol/L boron decreased the proportion of lymphocyte subsets, cytokine contents, proliferation rate of lymphocytes, and mRNA and protein expressions of PCNA. In contrast, the mRNA and protein expressions of Caspase-3 and protein expression of Bax were increased. These results indicate that ERK1/2 signaling pathway mainly regulates the effects of low-dose and high-dose boron on proliferation, apoptosis, and immune function of splenic lymphocytes.
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In this study, the impact of exopolysaccharides (EPS)-positive strain Weissella cibaria (W. cibaria) fermented sourdough on the quality of whole wheat fresh noodles (WWNs) and its improvement mechanisms were studied. The optimal fermentation conditions were found to be 30% sucrose content, fermented at 25 °C for 12 h, which yielded the highest EPS, 28.06 g/kg, in the W. cibaria fermented sourdough with sucrose (DW+). During storage, the sourdough reduced polyphenol oxidase activities and delayed the browning rate of noodles. The DW+ increased the hardness by 11.98% from 2184.99 to 2446.83 g, and the adhesiveness increased by 19.60%, i.e., from 72.01 to 86.13 gâs of the noodles. The EPS mitigated acidification of sourdough, prevented the disaggregation of glutenin macropolymers (GMP), and increased sourdough elastic modulus. In addition, scanning electron microscope and confocal laser scanning microscopy of noodles containing EPS sourdough also demonstrated the uniform distribution of gluten proteins. The starch granules were also closely embedded in the gluten network. Thus, the present work indicated that the EPS produced sourdough delayed browning and improved the WWNs texture, indicating its potential to enhance the quality of whole grain noodles.
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Lactobacillales , Triticum , Alimentos , SacaroseRESUMO
Previous studies have shown that per- and polyfluoroalkyl substances (PFAS) may have hepatotoxic effects in animals. However, epidemiological evidence in humans, especially pregnant women, is limited. This study aimed to assess the association of single and multiple PFAS exposure with serum markers of liver function in pregnant women. A total of 420 pregnant women from the Guangxi Zhuang Birth Cohort were enrolled from June 2015 to April 2019. Nine PFAS were measured in the maternal serum in early pregnancy. Data for liver function biomarkers, namely, alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyltransferase (GGT), total bilirubin (TBIL), direct bilirubin (DBIL), and indirect bilirubin (IBIL), were obtained from medical records. In generalized linear model (GLM), there was a positive association of perfluorooctane sulfonate (PFOS) with ALT, perfluorodecanoic acid (PFDA) and perfluorobutanesulfonic acid (PFBS) with GGT, and perfluorohexane sulfonate (PFHxS) with TBIL and IBIL. In contrast, there was a negative association of perfluoroheptanoic acid (PFHpA) with TBIL. There were inverse U-shaped relationships of PFUnA with ALT and AST and PFDA with ALT by restricted cubic spline. The weighted quantile sum (WQS) regression model revealed the positive effects of the PFAS mixture on GGT, TBIL, DBIL, and IBIL. Bayesian kernel machine regression (BKMR) analysis confirmed that the PFAS mixture was positively associated with GGT, and PFBS was the main contributor. In addition, the BKMR model showed a positive association of individual PFBS with GGT, individual PFHxS with TBIL and IBIL, and a negative association of individual PFHpA with TBIL. Our findings provide evidence of an association between individual PFAS, PFAS mixture and maternal serum markers of liver function during pregnancy. Additionally, these findings also enhance concerns over PFAS exposure on maternal liver function and PFAS monitoring in pregnancy, reducing the effect of maternal liver dysfunction on maternal and infant health.
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Ácidos Alcanossulfônicos , Poluentes Ambientais , Fluorocarbonos , Lactente , Animais , Humanos , Feminino , Gravidez , Exposição Materna , Poluentes Ambientais/toxicidade , Teorema de Bayes , China/epidemiologia , Fluorocarbonos/toxicidade , AlcanossulfonatosRESUMO
To differentiate whole wheat foods from refined wheat foods is still challenging grain industry and confusing consumers. Alkylresorcinols (ARs), as biomarkers of whole wheat grains, can serve for assessing the authenticity of whole wheat foods. Herein, a highly efficient fluorescence sensing platform (CDs@MIP) for rapid and sensitive analysis of ARs was explored, using carbon dots (CDs) as fluorophores and 5-heneicosylresorcinol (C21:0 AR) as template molecules embedded in a molecularly imprinted polymer (MIP) coating. Benefiting from the specific cavities in the probe and a photo-induced electron transfer effect, the fluorescence intensity of CDs@MIP was significantly quenched in the presence of C21:0 AR, exhibiting a superior binding efficiency and selectivity. As a result, the fabricated optical sensor delivered a wide linear range of C21:0 AR from 0.015 to 60 µg mL-1 with an ultralow detection limit of 4 ng mL-1. It was noteworthy that the sensor was successfully applied for the rapid detection of C21:0 AR in commercial whole-wheat foods as well as visualization analysis on the test paper, comprehensively validating the practicality and efficacy of CDs@MIP based fluorescence assay. The study provides a rapid and sensitive detection method of C21:0 AR, paving a new way for guiding grain industry to effectively qualify the authenticity and to quantify the content of whole wheat in wheat-based foods.
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Técnicas Biossensoriais , Impressão Molecular , Pontos Quânticos , Carbono/química , Limite de Detecção , Impressão Molecular/métodos , Polímeros Molecularmente Impressos , Pontos Quânticos/química , Triticum/químicaRESUMO
Streptococcus suis is a zoonotic pathogen that continuously threatens animal husbandry and public health worldwide. Studies have shown that S. suis can cause persistent infection by forming biofilms. In this study, a model of S. suis biofilm-related infection was successfully constructed for the first time by simulating the natural infection of S. suis, and biofilm of S. suis in vivo was successfully observed in the lung tissue of infected pigs by a variety of detection methods. Subsequently, selective capture of transcribed sequences (SCOTS) was used to identify genes expressed by S. suis in vivo biofilms. Sixty-nine genes were captured in in vivo biofilms formed by S. suis for the first time by SCOTS; they were mainly involved in metabolism, cell replication, and division, transport, signal transduction, cell wall, etc. Genes related to S. suis in vitro biofilm formation were also identified by SCOTS and RNA sequencing. Approximately half of the genes captured by SCOTS in the in vivo and in vitro biofilms were found to be different. In summary, our study provides powerful clues for future exploration of the mechanisms of S. suis biofilm formation. IMPORTANCE Streptococcus suis is considered an important zoonotic pathogen, and persistent infection caused by biofilm is currently considered to be the reason why S. suis is difficult to control in swine. However, to date, a model of the biofilm of S. suis in vivo has not been successfully constructed. Here, we successfully detected biofilms of S. suis in vivo in lung tissues of piglets infected with S. suis. Selective capture of transcribed sequences and the transcriptome were used to obtain gene profiles of S. suis in vivo and in vitro biofilms, and the results showed large differences between them. Such data are of importance for future experimental studies exploring the mechanism of biofilm formation by S. suis in vivo.
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Streptococcus suis , Transcriptoma , Animais , Suínos , Streptococcus suis/genética , Streptococcus suis/metabolismo , Infecção Persistente , Biofilmes , PulmãoRESUMO
BACKGROUND: Cardiovascular disease (CVD) is the leading cause of death. Oxidative stress is an important pathological process of a variety of CVDs. Xinshuaining preparation has a therapeutic effect on the heart failure. However, the anti-oxidative stress role of Xinshuaining preparation in H9c2 cells is still unclear. METHODS: The medicated serum of Xinshuaining preparation was acquired and utilized to hatch with H2O2-induced H9c2 cells. Main components in the Xinshuaining preparation were analyzed by liquid chromatography-mass spectrometry (LC/MS). The effect of medicated serum on the cell viability, apoptosis rate, the oxidative stress indicators (SOD, GSH-Px, and MDA), mitochondrial membrane potential (MMP), and ROS level was evaluated by CCK-8, flow cytometry, commercial biochemical detection kits, and JC-1 staining. Additionally, the associated mechanism was determined by the detection of the protein levels (PI3K, phosphorylated PI3K, Akt, phosphorylated Akt, and Nrf-2) through western blot assays, which was also further assessed with the application of LY294002. RESULTS: The medicated serum of Xinshuaining preparation notably increased the H2O2-reduced, the cell viability, the concentration of SOD and GSH-Px, MMP level and the relative protein expression level of phosphorylated PI3K and Akt and Nrf-2, while dampened the H2O2-elevated the level of the cell apoptosis rate, MDA, and ROS. However, Xinshuaining preparation on the cell viability, apoptosis, and oxidative stress was notably antagonized by LY294002 pre-treatment. CONCLUSIONS: The medicated serum of Xinshuaining preparation increased the cell viability and suppressed apoptosis and oxidative stress via the PI3K/Akt/Nrf-2 signaling pathway.
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Fosfatidilinositol 3-Quinases , Proteínas Proto-Oncogênicas c-akt , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Fosfatidilinositol 3-Quinases/farmacologia , Peróxido de Hidrogênio/toxicidade , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais , Estresse Oxidativo , Apoptose , Superóxido Dismutase/metabolismoRESUMO
Benzoic acids are always unstable during thermal processing. Herein, effects of typical molecular structure of benzoic acids and V-amylose on the formation and thermostability of inclusion complexes were investigated. Interestingly, the helical structure of six V-amylose transformed to V6a-amylose after complexing with four benzoic acids. Encapsulation efficiency (EE) and loading efficiency (LE) results presented that gentisic acid (DA) complexed with V6a-amylose achieving the highest EE of 79.76 % and LE of 7.25 %. X-ray diffraction (XRD) and differential scanning calorimetry (DSC) results demonstrated that DA, protocatechuic acid (PA), and gallic acid (GA) formed VI inclusion complexes with V-amylose, especially V6a-amylose-DA inclusion complexes with the highest crystallinity, while p-hydroxybenzoic acid (PHBA) was difficult to complex with V-amylose. Moreover, V6a-amylose-DA inclusion complexes showed the highest capacity in protecting the antioxidant activity from thermal processing. This suggested both V6a-amylose helical cavity and benzoic acids with para-hydroxyl structure facilitated the formation of thermostable inclusion complexes.
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Amilose , Benzoatos , Amilose/química , Antioxidantes , Ácido Gálico , Hidroxibenzoatos , Difração de Raios XRESUMO
Bisphenols are endocrine disruptor chemicals that disrupt thyroid hormone homeostasis. However, evidence on the effects of bisphenol mixtures on thyroid hormones are insufficient. Therefore, the present study aimed to explore the effects of bisphenol substitutes and bisphenol mixtures on thyroid hormones during pregnancy. The study was conducted among 446 pregnant women in the Guangxi Zhuang Birth Cohort (GZBC), China. In multiple linear regressions, compared with the low-exposure group, bisphenol S (BPS) concentrations in the middle-exposure group led to a 10.90% (95% CI: - 18.16%, - 2.99%) decrease in triiodothyronine (T3) levels in the first trimester; tetrabromobisphenol A (TBBPA) levels in the middle-exposure group led to an 8.26% (95% CI: - 15.82%, - 0.01%) decrease in T3 levels in the first trimester; bisphenol B (BPB) levels in the middle-exposure group led to higher free thyroxine (FT4) levels (9.84%; 95% CI: 1.73%, 18.60%) in the second trimester; bisphenol F (BPF) in the middle-exposure group led to higher FT4 levels (8.59%, 95% CI: 0.53%, 17.31%) in the second trimester; and TBBPA levels in the high-exposure group led to a 9.39% (95% CI: 1.46%, 17.93%) increase in FT4 levels in the second trimester. The Bayesian kernel machine regression (BKMR) and restricted cubic spline (RCS) models showed a U-shaped dose-response relationship between bisphenol A (BPA) and free triiodothyronine (FT3) (p < 0.01) as well as BPS and FT4 (p < 0.05). Nonlinear relationships were also observed between the bisphenol mixture and FT3. Overall, maternal bisphenol exposure affected thyroid hormone levels during pregnancy. This study provides evidence that BPB, BPF, BPS, and TBBPA are unsafe substitutes for BPA, as well as the overall effect of bisphenols on adverse health in human beings.
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Gestantes , Tri-Iodotironina , Humanos , Feminino , Gravidez , Estudos de Coortes , Estudos Prospectivos , Coorte de Nascimento , Teorema de Bayes , China , Compostos Benzidrílicos , Hormônios Tireóideos , PartoRESUMO
Alkylresorcinols (ARs) are a group of bioactive phenolic lipids and mostly concentrated in the bran of whole grains. In this study, the influences of alkyl chain length of ARs and V-amylose structure on the stability of V-amylose-ARs inclusion complexes were characterized. On the one hand, X-ray diffraction (XRD), differential scanning calorimetry (DSC), and in vitro digestion studies of complexes showed that the crystallinity, thermo-stability, and digestion resistance of V-amylose-ARs inclusion complexes increased with increasing alkyl chain length of ARs. On the other hand, V6-amylose-ARs inclusion complexes displayed the strongest thermostability, the highest crystallinity, and the lowest digestibility compared to V7-amylose-ARs inclusion complexes and V8-amylose-ARs inclusion complexes. It could be concluded that both the helical structure of hydrated V6-amylose and ARs with longer alkyl chain stabilized the structure and stability of the inclusion complexes. This work could pave a way to develop bioactive cereal foods with high bioaccessibility of ARs.
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Amilose , Amido , Amilose/química , Varredura Diferencial de Calorimetria , Amido/química , Difração de Raios XRESUMO
There have been three major global outbreaks of acute respiratory disease caused by coronavirus in the last two decades. The ongoing Coronavirus Disease 2019 (COVID-19) first emerged in Wuhan, China, is the most dangerous, which spread to 163 countries and 6 continents and caused a major public health emergency worldwide. The outbreak is caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) originated from bats, which spreads rapidly from human to human. As of 17 March 2020, there have been 179,112 confirmed cases and 7426 deaths worldwide, with a mortality rate of 4.1%. There is currently no effective treatment or approved vaccine, so isolating the source of infection and blocking the routes of transmission is important. In this article, we summarized the worldwide epidemic trend of COVID-19 and discussed its epidemiological characteristics, prevention and control measures. We hope this article could provide experience and help for global epidemic prevention and control.
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COVID-19 , China/epidemiologia , Surtos de Doenças , Humanos , SARS-CoV-2RESUMO
Photoresponsive surface molecularly imprinted polymers (PSMIPs) with controlled nanoshell thicknesses were synthesized using different amounts of precursor materials to determine the effects of polymer shell layer thickness on the separation and purification of 6-O-alpha-maltosyl-beta-cyclodextrin (Mal-ß-CD). The physicochemical properties and adsorption and desorption capacities of PSMIPs with different shell thicknesses were studied. Interestingly, the uniform thickness of the imprinted polymer shell layer could be adjusted from 10 to 60 nm by varying the amount of polymerization precursors, and the average mesopore diameter of PSMIPs was not significantly affected by shell thickness. However, the removal efficiency and selective capacity of PSMIPs on Mal-ß-CD were strongly correlated to their shell thickness. The adsorption behavior of PSMIPs on Mal-ß-CD fitted well with the Langmuir adsorption model and pseudo-second-order kinetic model. Based on the obtained results, PSMIPs with a 30-nm imprinted layer were found to be an excellent adsorbent for Mal-ß-CD separation, with an adsorption capacity of 18.12 mg/g. They can therefore be used for industrial chromatographic separations of Mal-ß-CD in the future. PRACTICAL APPLICATION: This article clearly demonstrated that the shell thickness of core-shell molecularly imprinted materials affected the degree and rate of cyclodextrin separation. Determining the optimal thickness is of great significance for the material in the separation and purification of cyclodextrin.
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Polímeros Molecularmente Impressos , Polímeros , beta-Ciclodextrinas , Adsorção , Polímeros Molecularmente Impressos/análise , Polímeros Molecularmente Impressos/química , Polimerização , Polímeros/isolamento & purificação , beta-Ciclodextrinas/químicaRESUMO
Acoustic wave can destabilize the flame and has a potential in firefighting, but the influences of the sound source and its frequency are still poorly understood. This work applies a loudspeaker to extinguish a laminar diffusion propane flame of 5-25 mm high, where the local sound frequency is 50-70 Hz and sound pressure is 0.8-3.2 Pa (92.0-104.1 dB). Results reveal a constant flame pulsating displacement at the extinction limit, independent of the sound environment used. Such a flame pulsating displacement is found to be caused by the motion of the speaker membrane (or diaphragm) and its induced wind, which could be two orders of magnitude larger than the displacement of the air that transmits acoustic wave. Thus, under the influence of sound source, a critical flame strain rate, stretched by the pulsating airflow, can be formulated to characterize the blow-off limit better than the local sound pressure. The sound source with a lower frequency can produce larger pulsating displacements of both membrane and flame, and thus promoting extinction. This work improves the understanding of flame dynamics under the external sound field and source, and it helps establish a scientific framework for acoustic-based fire suppression technologies.
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The immobilization of Thermomyces lanuginosus lipase on polydopamine-functionalized Fe3O4 magnetic nanoparticles (Fe3O4@PDA-TLL) as a nanobiocatalyst was successfully performed for the first time, and the Fe3O4@PDA-TLL was used for regioselective acylation of natural hyperoside with vinyl decanoate. The effects of several crucial factors, such as the reaction solvent, substrate molar ratio, temperature, and immobilized enzyme dosage, were investigated. Under optimum conditions, the reaction rate, 6â³-regioselectivity, and maximum substrate conversion were as high as 12.6 mM/h, 100%, and 100%, respectively. An operational stability study demonstrated that the immobilized enzyme could maintain 90.1% of its initial maximum conversion even after reusing it five times. In addition, further investigations on the kinetic parameters, like V max, K m, V max/K m, and E a, also revealed that the biocompatible Fe3O4@PDA could act as an alternative carrier for the immobilization of different enzymes.
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All-optical photonic crystal diodes based on the Fano resonance of nonlinear defects are studied. The diodes can achieve nonreciprocal transmission ratios of 31.7 dB and 33.9 dB at working wavelengths of 1534.83 nm and 1536.02 nm, respectively. The function of two defects' coupling to the performance of unidirectional light transmission is also analyzed. When two Fano cavities are cascaded to form a two-branch-channel diode, unidirectional light propagation at 1536.88, 1538.76, 1612.80, and 1616.78 nm wavelengths is achieved along two opposite forward directions, and the nonreciprocal transmission ratios are 36.5, 30.3, 23.9, and 19.6 dB, respectively.
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Based on the nonlinear resonators and self-collimation characteristics of light beams, we designed an all-optical photonic crystal beam splitter and switch. The proposed device consists of an input waveguide and three output waveguides connected to different ring resonators. Three pump beams transmit through different resonators via the self-collimation effect, and eight output states are realized by altering the intensity of the pump light. The proposed device works at the wavelength of 1629.57 nm, and the pump wavelength is located at 1240.00 nm. The transmittance contrast between the "on" and "off" states reached a maximum value of 124.0 and a minimum of 17.6. The minimal pump light intensity required to implement the performance is only ${0.162}\,\,{\rm W/}\unicode{x00B5}{\rm m}^2$0.162W/µm2, while the maximal value is about ${0.497}\,\,{\rm W/}\unicode{x00B5}{\rm m}^2$0.497W/µm2. Due to the small size of our proposed device and also its insensitivity to the pump light beams' incident location and spatial width within a certain degree, it has great potential application value in all-optical communications.