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In contrast to lithium-ion batteries, lithium-sulfur batteries have higher theoretical energy density and lower cost, so they would become competitive in the practical application. However, the shuttle effect of polysulfides and slow oxidation-reduction kinetics can degrade their electrochemical performance and cycle life. In this work, we have first developed the porous FeNi Prussian blue cubes as precursors. The calcination in different atmospheres was employed to make precursors convert into common pyrolysis products or novel carbon-based phosphides, and sulfides, labeled as FeNiP/A-C, FeNiP/A-P, and FeNiP/A-S. When these products serve as host materials in the sulfur cathode, the electrochemical performance of lithium-sulfur batteries is in the order of S@FeNiP/A-P > S@FeNiP/A-S > S@FeNiP/A-C. Specifically, the initial discharge capacity of S@FeNiP/A-P can reach 679.1 mAh g-1at 1 C, and the capacity would maintain 594.6 mAh g-1after 300 cycles. That is because the combination of carbon-based porous structure and numerous well-dispersed Ni2P/Fe2P active sites contribute FeNiP/A-P to obtain larger lithium-ion diffusion, lower resistance, stronger chemisorption, and more excellent catalytic effect than other samples. This work may deliver that metal-organic framework-derived carbon-based phosphides are more suitable to serve as sulfur hosts than carbon-based sulfides or common pyrolysis products for enhancing Li-S batteries' performance.
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In this study, the capillary electrophoresis-photodiode array detector was employed for the analysis of four iridoid compounds in Gentiana macrophylla Radix (RGM), and the method was optimized based on the concept of analytical quality by design (AQbD). The peak areas relative standard deviation (n = 3) and resolution of the four analytes were selected as critical method attributes. Fractional factorial design test combined with Pareto analysis were employed to screen critical method parameters (buffer concentration, pH, sodium dodecyl sulfate [SDS] micelle concentration, temperature, and voltage). Subsequently, three main factors (buffer concentration, buffer pH, and SDS concentration) were selected by central composite design test for constructing the design space. The optimal separation conditions as follows: capillary column (50.2 cm × 50 µm, detection length 40 cm). Working background electrolyte consisted of 51 mmol/L borax solution (pH = 9.47) and 40 mmol/L SDS. The samples were injected by pressure (5 s at 0.5 psi) and the detection was performed at 254 nm. Applied voltage was 20 kV and column temperature was 23°C. The developed method is rapid and reliable for the quantitative analysis of four iridoid compounds in RGM, providing a reference for the application of AQbD concept in the analysis of natural products.
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Medicamentos Herbarios Chinos , Gentiana , Iridoides , Electroforesis Capilar/métodos , Raíces de Plantas/química , Medicamentos Herbarios Chinos/análisisRESUMEN
The aim of this study was to establish a rapid quality assessment method for Gentianae Macrophyllae Radix (RGM) using near-infrared (NIR) spectra combined with chemometric analysis. The NIR spectra were acquired using an integrating sphere diffuse reflectance module, using air as the reference. Capillary electrophoresis (CE) analyses were performed on a model P/ACE MDQ Plus system. Partial least squares-discriminant analysis qualitative model was developed to distinguish different species of RGM samples, and the prediction accuracy for all samples was 91%. The CE response values at each retention time were predicted by building a partial least squares regression (PLSR) calibration model with the CE data set as the Y matrix and the NIR spectra data set as the X matrix. The converted CE fingerprints basically match the real ones, and the six main peaks can be accurately predicted. Transforming NIR spectra fingerprints into the form of CE fingerprints increases its interpretability and more intuitively demonstrates the components that cause diversity among samples of different species and origins. Loganic acid, gentiopicroside, and roburic acid were considered quality indicators of RGM and calibration models were built using PLSR algorithm. The developed models gave root mean square error of prediction of 0.2592% for loganic acid, 0.5341% for gentiopicroside, and 0.0846% for roburic acid. The overall results demonstrate that the rapid quality assessment system can be used for quality control of RGM.
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Glucósidos Iridoides , Espectroscopía Infrarroja Corta , Espectroscopía Infrarroja Corta/métodos , Glucósidos Iridoides/análisis , Análisis de los Mínimos Cuadrados , CalibraciónRESUMEN
A competitive electrochemiluminescence immunoassay was established based on the isoluminol-H2O2 (ABEI-H2O2) system catalyzed by cobalt hydroxide (Co(OH)2) to detect florfenicol residues in food. First , ultra-thin two-dimensional Co(OH)2 nanosheets were used as the catalyst of ABEI-H2O2 system, and excellent catalytic effects were acquired by catalytic decomposition of hydrogen peroxide with cobalt ions. Then, bimetal PdAg (Pd/Ag) alloy nanoparticles were used as a bridge to connect ABEI and antibody due to their good biocompatibility; Pd/Ag alloy nanoparticles also had a catalytic effect to further amplify the ECL signal in the system due to the synergistic catalytic effect of the bimetal. A competitive immunoassay strategy was used to detect florfenicol, where the florfenicol in the sample will compete with the antibody for the limited binding sites on the coating antigen. The ECL immunosensor for florfenicol detection shows high sensitivity, with a linear range from 10-4 to 102 ng mL-1, and a detection limit of 3.1 × 10-5 ng mL-1, where the scan potential was varied from 0 to 0.6 V vs Ag/AgCl . This work was the first to use Co(OH)2 nanosheets and bimetal PdAg catalytic signal amplification methods to design the sensor, which provides a novel, convenient and reliable strategy for ultra-sensitive detection of florfenicol, and other biological small molecules. A novel ECL immunosensor based on ABEI-H2O22.
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Técnicas Biosensibles , Nanopartículas del Metal , Aleaciones , Técnicas Biosensibles/métodos , Cobalto/química , Peróxido de Hidrógeno/química , Hidróxidos , Inmunoensayo/métodos , Límite de Detección , Mediciones Luminiscentes/métodos , Luminol/análogos & derivados , Nanopartículas del Metal/química , Tianfenicol/análogos & derivadosRESUMEN
Attapulgite(ATP), as a fertilizer slow-release agent and soil conditioner, has shown remarkable effect in improving the utilization rate of fertilizer and the yield and quality of agricultural products and Chinese medicinal materials. This study aims to explore the effect of ATP on the growth and root quality of Angelica sinensis. To be specific, Mingui 1 was used, and through the pot(soil culture) experiment in the Dao-di producing area, the effects of conventional chemical fertilizer added with ATP on the morphology, photosynthesis, soil respiration, and content of ferulic acid and volatile oil in roots of Mingui 1 were detected. The underlying mechanism was discussed from the perspective of source-sink relationship. The results showed that ATP, via the fertilizer slow-release effect, could meet the needs of A. sinensis for nutrients at the root expansion stage, improve the net photosynthetic rate of leaves and aboveground biomass of plants, and promote the transfer and accumulation of nutrients from the aboveground part(source) to the underground root(sink) in advance during the dry matter accumulation period of roots, so as to improve the root weight per plant. ATP can increase the content of total ferulic acid(the sum of free ferulic acid and coniferyl ferulate), the main effective component of Angelicae Sinensis Radix, by promoting the synthesis of ferulic acid in the roots and the transformation to coniferyl ferulate. However, it had little effect on the content of volatile oil. ATP had certain influence on soil respiration, which needs to be further explored from root activity, rhizosphere microorganisms, and soil microorganisms. This study can lay a basis for soil remediation and improvement and ecological cultivation of A. sinensis.
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Angelica sinensis , Aceites Volátiles , Adenosina Trifosfato , Angelica sinensis/química , Ácidos Cumáricos , Fertilizantes/análisis , Compuestos de Magnesio , Aceites Volátiles/química , Raíces de Plantas/química , Compuestos de Silicona , SueloRESUMEN
RATIONALE: Succus Bambusae is consumed as a kind of herbal medicine and natural beverage in China. However, the current quality standards for Succus Bambusae are low and lack safety indicators, which makes it difficult to effectively guarantee its quality. Therefore, it is of great significance to study the identification and quality control technology for the product. METHODS: We have developed a set of qualitative and quantitative methods based on gas chromatography/mass spectrometry (GC/MS) for the analysis of volatile components in Succus Bambusae oral liquid (SBOL). Combining GC/MS fingerprint analysis and related chemometrics algorithms, with similarity evaluation, Hotelling T2 and distance to Model X (DModX) as criteria, the quality consistency of different batches was evaluated, and SBOL samples from different manufacturers were differentiated. RESULTS: Twenty-nine volatile components were preliminarily identified from 40 batches of SBOL samples from six manufacturers, and six Q-markers (Quality Markers) for the SBOLs were discussed and determined using GC/MS. The products from different manufacturers were distinguished using chemometrics. CONCLUSIONS: The results showed that the quality of the SBOL samples from different batches and different manufacturers fluctuated greatly, which suggested that research into the raw materials and manufacturing techniques should be strengthened to improve the quality of SBOL and ensure its quality consistency.
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Quimiometría/métodos , Medicamentos Herbarios Chinos/química , Cromatografía de Gases y Espectrometría de Masas/métodos , China , Control de Calidad , Compuestos Orgánicos Volátiles/químicaRESUMEN
The present study determined five saponins in Xuesaitong Dropping Pills(XDP) by micellar electrokinetic chromatography(MEKC), and evaluated between-batch consistency by MEKC fingerprints and similarity analysis. A background buffer was composed of 20 mmol·L~(-1) sodium tetraborate-20 mmol·L~(-1) boric acid solution(pH 8.5), 55 mmol·L~(-1) sodium dodecyl sulfate(SDS), 23 mmol·L~(-1) ß-cyclodextrin, and 13% isopropyl alcohol. All separations were performed at 25 â,20 kV and the detection wavelength was set at 203 nm. The separation channel was a fused silica capillary with a dimension of 75 µm I.D. and a total length of 50.2 cm(effective length of 40.0 cm). The contents of notoginsenoside R_1, and ginsenosides Rg_1, Re, Rb_1, Rd were determined with their quality control ranges set. The fingerprints of XDP were established and the between-batch consistency was evaluated by similarity analysis. The contents of five saponins from the 19 batches of XDP were stable in the fixed ranges. Statistical analysis was carried out on the results of multiple batches of samples, and the specific quality control ranges were recommended as follows: notoginsenoside R_1 21.92-34.16 mg·g~(-1), ginsenosides Rg_1 83.54-131.78 mg·g~(-1), ginsenosides Re 13.58-19.82 mg·g~(-1), ginsenosides Rb_1 89.40-129.90 mg·g~(-1), and ginsenosides Rd 22.34-35.67 mg·g~(-1). Eleven characteristic peaks were identified in the fingerprints. Five peaks, notoginsenoside R_1 and ginsenosides Rg_1, Re, Rb_1, Rd, were identified with reference standards. The similarities of the 19 batches of samples were all above 0.988, indicating good between-batch consistency. This method is green and simple, and can be used for the quantitative determination and quality evaluation of XDP. It can also provide references for the quality control of other Chinese medicinal dripping pills.
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Cromatografía Capilar Electrocinética Micelar , Medicamentos Herbarios Chinos , Micelas , Control de Calidad , SaponinasRESUMEN
The relationship between fractional-order heat conduction models and Boltzmann transport equations (BTEs) lacks a detailed investigation. In this paper, the continuity, constitutive and governing equations of heat conduction are derived based on fractional-order phonon BTEs. The underlying microscopic regimes of the generalized Cattaneo equation are thereafter presented. The effective thermal conductivity κeff converges in the subdiffusive regime and diverges in the superdiffusive regime. A connection between the divergence and mean-square displacement ã|Δx|2ã â¼ tγ is established, namely, κeff â¼ tγ-1, which coincides with the linear response theory. Entropic concepts, including the entropy density, entropy flux and entropy production rate, are studied likewise. Two non-trivial behaviours are observed, including the fractional-order expression of entropy flux and initial effects on the entropy production rate. In contrast with the continuous time random walk model, the results involve the non-classical continuity equations and entropic concepts. This article is part of the theme issue 'Advanced materials modelling via fractional calculus: challenges and perspectives'.
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The long-term and extensive use of chemical fertilizers and pesticides in the cultivation of Chinese materia medica has resulted in serious soil ecological and environmental problems such as secondary salinization, soil consolidation, soil acidification, continuous cropping obstacles, micro-ecological imbalance, and serious soil pests and diseases in the production areas of Chinese materia medica. Therefore, promoting the ecological planting of Chinese materia medica is the only way for the production of Chinese materia medica. Attapulgite(ATP) is a kind of water-rich magnesium-rich aluminosilicate clay mineral with layered and chain structure. It has abundant reserves in China, possesses nano-material properties, strong adsorption and ion exchange properties, and has huge high value utilization space. ATP and its functional products have the potential of water and fertilizer conservation, regulating soil structure and micro-ecology, and are widely used in ecological planting of Chinese materia medica. This paper reviews the resource distribution, structural characteristics, the research and application progress in soil ecological effects of ATP, and prospects the application prospects of it in the ecological planting of Chinese materia medica.
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Medicamentos Herbarios Chinos , Materia Medica , China , Compuestos de Magnesio , Medicina Tradicional China , Compuestos de Silicona , SueloRESUMEN
BACKGROUND The aim of this study was to assess the association of single-nucleotide polymorphisms (SNPs) in IL1R1 with the risk of lumbar disc herniation (LDH) in the Han population in northwest China. MATERIAL AND METHODS To estimate the association of IL1R1 polymorphisms with LDH risk, Agena MassARRAY was used to determine the genotypes of 498 LDH patients and 463 controls. The association between IL1R1 variants and LDH risk was examined by logistic regression analysis with adjustments for age and gender. Stratification analysis was observed between gender and age with polymorphisms of IL1R1. Haplotype construction and analysis in IL1R1 were also applied to detect the potential association. RESULTS The mutant homozygous genotype in codominant model (AA versus GG, OR=2.37, 95% CI: 1.08-5.21, P=0.001) and in recessive model (AA versus GG/GA, OR=2.82, 95% CI: 1.30-6.12, P=0.005) of rs956730 were associated with an increased LDH risk in males, while rs956730 heterozygous genotype under codominant model (AG versus GG, OR=0.65, 95% CI: 0.46-0.92, P=0.001) was a protective genotype in males. In addition, the recessive model (CT/CC versus TT, OR=3.43, 95% CI: 1.11-10.57, P=0.020) of rs10490571 was associated with an increased LDH risk among people older than 50 years of age. CONCLUSIONS This study demonstrated that genetic variants in the IL1R1 genes were associated with LDH risk in the Han population of northwestern China.
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Desplazamiento del Disco Intervertebral/genética , Receptores Tipo I de Interleucina-1/genética , Adulto , Anciano , Pueblo Asiatico/genética , Estudios de Casos y Controles , China/epidemiología , Etnicidad/genética , Femenino , Frecuencia de los Genes/genética , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Genotipo , Haplotipos/genética , Humanos , Desplazamiento del Disco Intervertebral/epidemiología , Desplazamiento del Disco Intervertebral/patología , Vértebras Lumbares/metabolismo , Vértebras Lumbares/patología , Masculino , Persona de Mediana Edad , Polimorfismo de Nucleótido Simple , Factores de RiesgoRESUMEN
Generalized expressions of the entropy and related concepts in non-Fourier heat conduction have attracted increasing attention in recent years. Based on standard and fractional phonon Boltzmann transport equations (BTEs), we study entropic functionals including entropy density, entropy flux and entropy production rate. Using the relaxation time approximation and power series expansion, macroscopic approximations are derived for these entropic concepts. For the standard BTE, our results can recover the entropic frameworks of classical irreversible thermodynamics (CIT) and extended irreversible thermodynamics (EIT) as if there exists a well-defined effective thermal conductivity. For the fractional BTEs corresponding to the generalized Cattaneo equation (GCE) class, the entropy flux and entropy production rate will deviate from the forms in CIT and EIT. In these cases, the entropy flux and entropy production rate will contain fractional-order operators, which reflect memory effects.
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CouR, a MarR-type transcriptional repressor, regulates the cou genes, encoding p-hydroxycinnamate catabolism in the soil bacterium Rhodococcus jostii RHA1. The CouR dimer bound two molecules of the catabolite p-coumaroyl-CoA (Kd = 11 ± 1 µM). The presence of p-coumaroyl-CoA, but neither p-coumarate nor CoASH, abrogated CouR's binding to its operator DNA in vitro. The crystal structures of ligand-free CouR and its p-coumaroyl-CoA-bound form showed no significant conformational differences, in contrast to other MarR regulators. The CouR-p-coumaroyl-CoA structure revealed two ligand molecules bound to the CouR dimer with their phenolic moieties occupying equivalent hydrophobic pockets in each protomer and their CoA moieties adopting non-equivalent positions to mask the regulator's predicted DNA-binding surface. More specifically, the CoA phosphates formed salt bridges with predicted DNA-binding residues Arg36 and Arg38, changing the overall charge of the DNA-binding surface. The substitution of either arginine with alanine completely abrogated the ability of CouR to bind DNA. By contrast, the R36A/R38A double variant retained a relatively high affinity for p-coumaroyl-CoA (Kd = 89 ± 6 µM). Together, our data point to a novel mechanism of action in which the ligand abrogates the repressor's ability to bind DNA by steric occlusion of key DNA-binding residues and charge repulsion of the DNA backbone.
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Acilcoenzima A/química , Proteínas Bacterianas/química , ADN/química , Regulación Bacteriana de la Expresión Génica , Proteínas Represoras/química , Acilcoenzima A/metabolismo , Alanina/química , Alanina/metabolismo , Sustitución de Aminoácidos , Arginina/química , Arginina/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Sitios de Unión , Coenzima A/química , Coenzima A/metabolismo , Ácidos Cumáricos/química , Ácidos Cumáricos/metabolismo , Cristalografía por Rayos X , ADN/metabolismo , Interacciones Hidrofóbicas e Hidrofílicas , Ligandos , Modelos Moleculares , Regiones Promotoras Genéticas , Propionatos , Unión Proteica , Dominios y Motivos de Interacción de Proteínas , Multimerización de Proteína , Proteínas Represoras/genética , Proteínas Represoras/metabolismo , Rhodococcus , Electricidad Estática , Transcripción GenéticaRESUMEN
Many rhodococci are oleaginous and, as such, have considerable potential for the sustainable production of lipid-based commodity chemicals. Herein, we demonstrated that Rhodococcus jostii RHA1, a soil bacterium that catabolizes a wide range of organic compounds, produced wax esters (WEs) up to 0.0002% of its cellular dry weight during exponential growth on glucose. These WEs were fully saturated and contained primarily 31 to 34 carbon atoms. Moreover, they were present at higher levels during exponential growth than under lipid-accumulating conditions. Bioinformatics analyses revealed that RHA1 contains a gene encoding a putative fatty acyl coenzyme A (acyl-CoA) reductase (FcrA). The purified enzyme catalyzed the NADPH-dependent transformation of stearoyl-CoA to stearyl alcohol with a specific activity of 45 ± 3 nmol/mg · min and dodecanal to dodecanol with a specific activity of 5,300 ± 300 nmol/mg · min. Deletion of fcrA did not affect WE accumulation when grown in either carbon- or nitrogen-limited medium. However, the ΔfcrA mutant accumulated less than 20% of the amount of WEs as the wild-type strain under conditions of nitric oxide stress. A strain of RHA1 overproducing FcrA accumulated WEs to â¼13% cellular dry weight under lipid-accumulating conditions, and their acyl moieties had longer average chain lengths than those in wild-type cells (C17 versus C16). The results provide insight into the biosynthesis of WEs in rhodococci and facilitate the development of this genus for the production of high-value neutral lipids.IMPORTANCE Among the best-studied oleaginous bacteria, rhodococci have considerable potential for the sustainable production of lipid-based commodity chemicals, such as wax esters. However, many aspects of lipid synthesis in these bacteria are poorly understood. The current study identifies a key enzyme in wax ester synthesis in rhodococci and exploits it to significantly improve the yield of wax esters in bacteria. In so doing, this work contributes to the development of novel bioprocesses for an important class of oleochemicals that may ultimately allow us to phase out their unsustainable production from sources such as petroleum and palm oil.
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In this paper, we have combined experimental neurophysiologic recording and statistical analysis to investigate the nonlinear characteristic and the cognitive function of the brain. Spectrum and bispectrum analyses are proposed to extract multiple effective features of electroencephalograph (EEG) signals from Alzheimer's disease (AD) patients and further applied to distinguish AD patients from the normal controls. Spectral analysis based on autoregressive Burg method is first used to quantify the power distribution of EEG series in the frequency domain. Compared to the control group, the relative power spectral density of AD group is significantly higher in the theta frequency band, while lower in the alpha frequency bands. In addition, median frequency of spectrum is decreased, and spectral entropy ratio of these two frequency bands undergoes drastic changes at the P3 electrode in the central-parietal brain region, implying that the electrophysiological behavior in AD brain is much slower and less irregular. In order to explore the nonlinear high order information, bispectral analysis which measures the complexity of phase-coupling is further applied to P3 electrode in the whole frequency band. It is demonstrated that less bispectral peaks appear and the amplitudes of peaks fall, suggesting a decrease of non-Gaussianity and nonlinearity of EEG in ADs. Notably, the application of this method to five brain regions shows higher concentration of the weighted center of bispectrum and lower complexity reflecting phase-coupling by bispectral entropy. Based on spectrum and bispectrum analyses, six efficient features are extracted and then applied to discriminate AD from the normal in the five brain regions. The classification results indicate that all these features could differentiate AD patients from the normal controls with a maximum accuracy of 90.2%. Particularly, different brain regions are sensitive to different features. Moreover, the optimal combination of features obtained by discriminant analysis may improve the classification accuracy. These results demonstrate the great promise for scape EEG spectral and bispectral features as a potential effective method for detection of AD, which may facilitate our understanding of the pathological mechanism of the disease.
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Enfermedad de Alzheimer/fisiopatología , Encéfalo/fisiopatología , Electroencefalografía/métodos , Procesamiento de Señales Asistido por Computador , Anciano , Femenino , Humanos , MasculinoRESUMEN
In this paper, weighted-permutation entropy (WPE) is applied to investigating the complexity abnormalities of Alzheimer's disease (AD) by analyzing 16-channel electroencephalograph (EEG) signals from 14 severe AD patients and 14 age-matched normal subjects. The WPE values are estimated in the delta, the theta, the alpha, and the beta sub-bands for each channel with an overlapped sliding window. WPE is modified from the permutation entropy (PE), which has been recently suggested as a measurement to extract the complexity of the EEG signals. The advantage of WPE over PE is verified by both the model simulated and the experimental EEG signals. Although the results show that both the average PE and WPE of AD patients are decreased in contrast with the normal group in these four sub-bands, especially in the theta band, WPE can exhibit a better performance in distinguishing the AD patients from the normal controls by the more significant differences in the four sub-bands, which may be attributed to the brain dysfunction. Thus, it suggests that WPE may become a probable useful tool to detect brain dysfunction in AD and it seems to be promising to disclose the abnormalities of brain activity for other neural disease.
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Enfermedad de Alzheimer/fisiopatología , Electroencefalografía , Procesamiento de Señales Asistido por Computador , Anciano , Anciano de 80 o más Años , Algoritmos , Enfermedad de Alzheimer/diagnóstico , Encéfalo/fisiopatología , Simulación por Computador , Entropía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Dinámicas no Lineales , Probabilidad , Reproducibilidad de los ResultadosRESUMEN
4-coumarate coenzyme A ligase is a key enzyme of phenylpropanoid metabolic pathway in higher plant and may regulate the biosynthesis of ferulic acid in Angelica sinensis. In this study, the homology-based cloning and rapid amplification of cDNA ends (RACE) technique were used to clone a full length cDNA encoding 4-coumarate coenzyme A ligase gene (4CL), and then qRT-PCR was taken for analyzing 4CL gene expression levels in the root, stem and root tissue at different growth stages of seedlings of A. sinensis. The results showed that a full-length 4CL cDNA (1,815 bp) was obtained (GenBank accession number: KT880508) which shares an open reading frame (ORF) of 1 632 bp, encodes 544 amino acid polypeptides. We found 4CL gene was expressed in all tissues including leaf, stem and root of seedlings of A. sinensis. The expressions in the leave and stem were increased significantly with the growth of seedlings of A. sinensis (P < 0.05), while it in the root showed little change. It indicates a time-space pattern of 4CL gene expression in seedlings of A. sinensis. These findings will be useful for establishing an experiment basis for studying the structure and function of 4CL gene and elucidating mechanism of ferulic acid biosynthesis and space-time regulation in A. sinensis.
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Angelica sinensis/genética , Clonación Molecular , Coenzima A Ligasas/genética , Secuencia de Aminoácidos , Secuencia de Bases , ADN Complementario/química , Datos de Secuencia MolecularRESUMEN
The activation of endogenous Oct4 transcription is a key step in the reprogramming of somatic cells into induced pluripotent stem (iPS) cells but until now it has been difficult to analyze this critical event in the reprogramming process. We have generated a transgenic mouse that expresses the tamoxifen-inducible Cre recombinase MerCreMer under the control of the endogenous Oct4 locus, enabling lineage tracing of Oct4 expression in cells in vivo or in vitro, during either reprogramming or differentiation. Using this novel resource, we have determined the timing and outcome of endogenous Oct4 induction during fibroblast reprogramming. We show that both the initiation of this key reprogramming step and the ability of cells activating endogenous Oct4 expression to complete reprogramming are not influenced by the presence of exogenous c-Myc, although the overall efficiency of the process is increased by c-Myc. Oct4 lineage tracing reveals that new reprogramming events continue to initiate over a period of 3 weeks. Furthermore, the analysis of mixed colonies, where only a subset of daughter cells induce endogenous Oct4 expression, indicates the role of unknown, stochastic events in the progression of reprogramming from the initial events to a pluripotent state. Our transgenic mouse model and cells derived from it provide powerful and precise new tools for the study of iPS cell reprogramming mechanisms and have wider implications for the investigation of the role of Oct4 during development.
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Células Madre Pluripotentes Inducidas/metabolismo , Factor 3 de Transcripción de Unión a Octámeros/metabolismo , Animales , Linaje de la Célula , Células Cultivadas , Embrión de Mamíferos/citología , Fibroblastos/metabolismo , Fibroblastos/fisiología , Regulación del Desarrollo de la Expresión Génica , Técnicas de Sustitución del Gen , Proteínas Fluorescentes Verdes/biosíntesis , Proteínas Fluorescentes Verdes/genética , Células Madre Pluripotentes Inducidas/fisiología , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Factor 3 de Transcripción de Unión a Octámeros/genética , Fenotipo , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/genética , Activación TranscripcionalRESUMEN
OBJECTIVE: To study the anti-hepatic fibrosis effect of serum containing extracts of Periplaneta americana. METHODS: The serum contained extracts of Periplaneta americana was prepared with serologic pharmacological method. MTT method was used to observe the effect of serum containing extracts from periplaneta americana on hepatic stellate cells (HSC), and Elisa method was used to detect the contents of TGF-beta1 and collagen I in supernatant. RESULTS: Serum containing extracts I and II (15%) of Periplaneta americana had inhibitory effect on HCS (P < 0.05) after HSC were cultured with serum containing extracts of different concentration of Periolaneta americana for 24, 48 and 72 h. At 24 and 48 h, serum containing extracts I and II of Periplaneta americana decreased the content of collagen I in supernatant without significant difference (P < 0.05). Serum containing extracts I (15%, 9%, 5.4%) of Periplaneta americana could reduce generation of TGF-beta1 in supernatant for 24 h (P < 0.05). As for 48 h, only high concentration serum containing extracts I (15%) deceased the content of TGF-beta1 in supernatant. For 24 and 48 h,serum containing extracts II couldn't reduce the content of TGF-beta1 in supernatant (P < 0.05). CONCLUSION: It has definite effect on anti-hepatic fibrosis with serum containing extracts of Periplaneta americana in vitro. The mechanism may be related to inhibiting HSC propagation and reducing the production of TGF-beta1.
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Colágeno Tipo I/metabolismo , Células Estrelladas Hepáticas/metabolismo , Cirrosis Hepática/patología , Materia Medica/farmacología , Periplaneta/química , Factor de Crecimiento Transformador beta1/metabolismo , Animales , Línea Celular , Ensayo de Inmunoadsorción Enzimática , Regulación de la Expresión Génica/efectos de los fármacos , Células Estrelladas Hepáticas/efectos de los fármacos , Cirrosis Hepática/metabolismo , Masculino , Materia Medica/aislamiento & purificación , Distribución Aleatoria , Ratas , Ratas Wistar , Suero/químicaRESUMEN
As a complex food, meat displays various biochemical properties that are determined to a great extent by physical architecture and lipid metabolites. Pekin duck and Liancheng white duck are elite breeds with distinct characteristics. Here, we explored the development of the muscle fibers from embryonic stage to 10-wk after birth, and muscle fibers grow slowly after 8-wk. We investigated the meat quality, ultrastructure, lipidomics profiling, and lipids spatial distribution of skeletal muscle at 8 wk. Pekin duck has lower Warner-Bratzler shear force (WBSF) (P < 0.05), high intramuscular fat (IMF) (P < 0.01), longer and wider sarcomere, and higher mitochondrial density (P < 0.001). Liancheng white duck with tighter collagen architecture. A total of 950 lipids from 6 lipid classes identified with lipidomics were analyzed, the levels of GP, GL, and PR were significantly higher in Pekin duck (P < 0.05), SL and ST were significantly higher in Liancheng white duck (P < 0.05). There were 333 significantly different lipids (|log2(Fold Change)| ≥ 1 and FDR < 0.05) screened, most lipids distributed in the muscle tissue were uniform, but some specifically distributed in connective tissue. To some extent, the results demonstrate the high lipid deposition capacity of Pekin duck and the high medicinal function of Liancheng white duck. Our study provides new insights into the relationship between skeletal muscle architecture and meat toughness, which increased the knowledge of lipidomic characteristics and provide a basis for duck meat authentication.
Asunto(s)
Pollos , Patos , Animales , Patos/metabolismo , Músculo Esquelético/metabolismo , Lípidos , Carne/análisisRESUMEN
Diabetic macular edema (DME) is a significant complication of diabetes that impacts the eye and is a primary contributor to vision loss in individuals with diabetes. Early control of the related risk factors is crucial to reduce the incidence of DME. Artificial intelligence (AI) clinical decision-making tools can construct disease prediction models to aid in the clinical screening of the high-risk population for early disease intervention. However, conventional machine learning and data mining techniques have limitations in predicting diseases when dealing with missing feature values. To solve this problem, a knowledge graph displays the connection relationships of multi-source and multi-domain data in the form of a semantic network to enable cross-domain modeling and queries. This approach can facilitate the personalized prediction of diseases using any number of known feature data. In this study, we proposed an improved correlation enhancement algorithm based on knowledge graph reasoning to comprehensively evaluate the factors that influence DME to achieve disease prediction. We constructed a knowledge graph based on Neo4j by preprocessing the collected clinical data and analyzing the statistical rules. Based on reasoning using the statistical rules of the knowledge graph, we used the correlation enhancement coefficient and generalized closeness degree method to enhance the model. Meanwhile, we analyzed and verified these models' results using link prediction evaluation indicators. The disease prediction model proposed in this study achieved a precision rate of 86.21%, which is more accurate and efficient in predicting DME. Furthermore, the clinical decision support system developed using this model can facilitate personalized disease risk prediction, making it convenient for the clinical screening of a high-risk population and early disease intervention.