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Lateral flow strip was widely used and their qualitative and quantitative performance was in continuous improvement. However, the traditional strip was in a single-test-line format, which restricted operators to making a semi-quantitative judgment around a desired threshold concentration. Herein, a single strip with three test lines (TTLS) was developed for the semi-quantitative and quantitative determination of deoxynivalenol (DON). Four visual detection thresholds were obtained under optimized conditions and 35 wheat samples with DON content from 45 µg/kg to 2841 µg/kg were used to verify the method. The detection results were compared with that of the traditional strip and UPLC-MS/MS. In a three-test-line format, TTLS could reveal at least 200, 500, 1000, and 2000 µg/kg DON existed in different samples by the naked eye. The agreement analysis and statistical results indicated the new TTLS can be used as a useful tool for quantitative detection of DON with wide dynamic range.
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Espectrometría de Masas en Tándem , Triticum , Espectrometría de Masas en Tándem/métodos , Cromatografía Liquida/métodos , Contaminación de Alimentos/análisisRESUMEN
The importance of catalysts today as workhorses in most modern industrial fields cannot be downplayed. As a result, rational design and engineering of targeted catalysts have emerged as key objectives and are dependent on in-depth understanding of complex catalytic dynamics. Synchrotron radiation (SR) light sources with rich advanced experimental methods are being recognized as a comprehensive characterization platform, which can draw a full picture on such multiparameter-involved catalysis under actual working conditions. Herein, the recent progress of catalytic dynamics process studied by the means of various SR techniques is summarized. In particular, SR-based spectroscopic, scattering, and imaging investigations on true catalysts are first introduced with the potential of in situ and operando characterizations. Apparently, the limitations from single SR technique naturally prompt a simple combination of SR techniques to better understand the whole catalysis process. Moreover, the discrepancies among various online testing facilities and batches of samples, along with random/systematic errors introduced by traditional intermittent/asynchronous measurement make it imperative to develop more prolific systems, complementary of multiple SR techniques for deep probing of dynamic catalytic processes. It is believed that the booming new light sources can further enrich the current multiple SR techniques, and thus may realize the true visualization on future catalytic dynamic processes.
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Despite their widely used and access as biological reagents in analytical methods, the detailed structural features for most of the antibodies were rarely known. Here, a new antibody for AFB1 with high specificity in constructing ELISA was studied in detail. The molecular structure and modification were elucidated mainly by nano-electrospray ionization mass spectrometry. The mass experiments, including MALDI-TOF MS, revealed complete and specific fragments, including antibody molecular weight, peptides, glycopeptide, and N-glycoform. By proteolytic treatment of pepsin and trypsin and high-resolution tandem-MS, the primary structure of the newly developed anti-AFB1 antibody was assembled by several rounds of Database search process assisted with the de novo results. The antibody CDR annotation and constraint-based multiple alignment tool were used to differentiate and align the sequences. The method uses only two proteases to generate numerous peptides for de novo sequencing. This artificial assembled AFB1-specific monoclonal antibody sequence was validated by comparison with the sequencing results of the immunoglobulin gene. The results showed that this method achieves full sequence coverage of anti-AFB1 monoclonal antibody, with an accuracy of 100% in the CDR regions of light chain and four amino acid mismatch in heavy chain. This simple and low-cost method was confirmed by treating a public dataset. The secondary structure information of intact antibody was also elucidated from the results of circular dichroism spectrum.
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Anticuerpos Monoclonales , Pepsina A , Aminoácidos , Anticuerpos Monoclonales/química , Glicopéptidos , Péptidos/química , Análisis de Secuencia de Proteína/métodos , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Tripsina/metabolismoRESUMEN
In this work, we report the structure-dependent electrochemical performance of cobalt carbonate hydroxide (Co2(OH)2CO3) nanocrystals by experimental investigation and theoretical simulation. Different Co2(OH)2CO3 nanostructures including two-dimensional (2D) nanosheets (NSs) and one-dimensional (1D) nanowires (NWs), were synthesized on self-supported carbon cloth substrates by a facile hydrothermal method. Compared to 1D NWs, 2D Co2(OH)2CO3 NSs provided a short ion transfer path, and low electron transfer resistance during the electrochemical reaction. At the current density of 2 mA cm-2, 2D Co2(OH)2CO3 NSs exhibited a higher area capacitance of 2.15F cm-2 and better cycling performance (96.2% retention after 10,000 cycles) than that of 1D NWs (1.15F cm-2 and 90.1% retention). First-principles density functional theory (DFT) calculations revealed that the band gap of the (120) facet in 2D NSs was 0.2 eV, far less than of the (200) facet in 1D NWs (1.04 eV). Electrochemical impedance spectroscopy (EIS) measurements further indicated that the electron transfer and reaction kinetics were more efficient in 2D NSs. This work can provide an important insight in understanding the mechanism of electrochemical energy storage.
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Electrocatalysis is recognized as a significant process for energy conversion. In fact, numerous factors, including the variable electronic structure of electrocatalysts, rich intermediates, and mutable active phases, have important but complex influences on the catalytic process. In addition, the support of electrocatalysts is considered as one of key factors that correlate to the final catalytic performance. In this Perspective, some recent advances regarding the support effects in electrocatalysis are briefly summarized. Synchrotron radiation-based characterizations are introduced to reveal the support-induced modulation in electrocatalysts. Recent in situ/operando studies are emphasized for better understanding of the real interaction between catalysts and support, together with visualizing the dynamic catalytic process. Some perspectives are proposed that may accelerate more attention being given to the support's optimization for future practical applications.
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Técnicas Electroquímicas/métodos , Sincrotrones , CatálisisRESUMEN
Cyclodextrin metal-organic framework (CD-MOF) as a highly porous supramolecular carrier could be one of the solutions to the insolubility of isosteviol (STV). The solubility of STV was lower than 20.00 ng/mL at pH 1.0 and pH 4.5, whilst its solubility increased to 20,074.30 ng/mL at pH 6.8 and 129.58 ng/mL in water with a significant pH-dependence. The in vitro release profiles of STV from STV@CD-MOF (0.5:1) were pH-independent in distinct pH media and closed to be thoroughly released but no such release profiles were observed for STV@CD-MOF (1:1) owing to nanoclusters formation. The bioavailability of STV@CD-MOF (1:1) in rats was 8.67-fold higher than that of STV, and was 1.32- and 1.27-fold higher than that of STV@CD and STV@CD-MOF (0.5:1). Our results indicated that the inclusion mechanism played a primary role when STV in CD-MOF was at a low loading ratio, while the increasement in bioavailability at a high loading ratio, which was attributed to the nanocluster mechanism. This was confirmed by molecular simulation. In conclusion, CD-MOF is a promising system for STV loading, overcoming the insolubility and to improve the bioavailability of this natural compound.
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Although hepatocellular carcinoma (HCC) is a type of carcinoma with high malignancy, high morbidity and low survival rate, its underlying mechanism has not been entirely elucidated. Abnormal lncRNAs involve many diseases such as neurological diseases, tumors, cardiovascular diseases, immune-mediated disorders, and genetic disorders. The abnormal expression of several lncRNAs is involved in HCC. This paper describes the roles of lncRNAs in promoting and maintaining tumor initiation and progression, interactions between lncRNAs and miRNAs, and exosomes associated with lncRNAs in HCC. We introduce their prospective clinical applications as tumor markers for the diagnosis, treatment, prognosis, and recurrence of HCC. This paper will help us better understand how lncRNAs produce their effects on HCC and provide general directions and strategies to conduct further research.
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Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/terapia , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/terapia , Redes y Vías Metabólicas/genética , ARN Largo no Codificante/genética , Animales , Carcinoma Hepatocelular/diagnóstico , Exosomas/genética , Humanos , Neoplasias Hepáticas/diagnósticoRESUMEN
Soil salinity is contributed largely by NaCl but some halophytes such as Sesuvium portulacastrum have evolved to adapt salinity environment and demonstrate optimal development under moderate salinity. To elucidate the detail mechanisms of the great salt tolerance and determine the respective contributions of Na(+), K(+) and Cl(-) on the development of S. portulacastrum, morphological and physiological analysis were performed using plants supplied with 200 mM of different ions including cations (Na(+), K(+), Li(+)) and anions (Cl(-), NO(3)(-), Ac(-)) respectively. The results revealed that the salt-treated plants accumulated large amounts of sodium in both leaf and stem. There was a greater shoot growth in presence of external Na(+) compared to K(+) and Cl(-). Na(+) was found more effective than K(+) and Cl(-) in cell expansion, leaf succulence, and shoot development. Flame emission and X-Ray microanalysis revealed the relative Na(+) content was much higher than K(+) and Cl(-) in both leaf and stem of well developed S. portulacastrum, leading to a higher Na(+)/K(+) ratio. The effects of different ions on the development of S. portulacastrum were listed as the following: Na(+) > NO(3)(-) > CK > Cl(-) > K(+) > Ac(-) > Li(+). These results demonstrated NaCl toxicity is attributable largely to the effect of Cl(-) but rarely to Na(+), and thus sodium is concluded as a more important macronutrient than potassium and chloride for improving leaf succulence and shoot development of halophyte S. portulacastrum.