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1.
Microb Pathog ; 191: 106669, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38697231

RESUMO

African swine fever (ASF) is a lethal disease caused by ASF virus (ASFV), severely impacting the global swine industry. Though nuclear acid-based detection methods are reliable, they are laboratory-dependent. In this study, we developed a device-independent, user friendly and cost-effective quantum dots based immunochromatographic strip (QDs-ICS) with high specificity and sensitivity for the rapid and on-site detection of ASFV antigen. For the preparation of the QDs-ICS, we generated a monoclonal antibody (mAb) mAb-8G8 and polyclonal antibody (pAb) against ASFV-p72 protein. The pAb was labelled with QDs to be used as the detection probe and the mAb-8G8 was coated on the nitrocellulose membrane as the test line. Our results proved that the strip displayed no cross-reactivity with other swine viruses and detection limit of the QDs-ICS was down to 1 ng/mL for the ASFV-p72 protein with great reproducibility. The strip also exhibited high stability with a storage period up to 12 months under room temperature. Twenty blind samples and one hundred clinical samples were examined by the QDs-ICS, conventional PCR and real-time PCR method, respectively. Results showed that the agreement rate between the QDs-ICS and PCR method was 100%, and the agreement rate between the strip and real-time PCR was 94%. The novel QDs-ICS developed here would be an effective tool for on-site detection of ASFV.


Assuntos
Vírus da Febre Suína Africana , Febre Suína Africana , Anticorpos Monoclonais , Anticorpos Antivirais , Antígenos Virais , Cromatografia de Afinidade , Pontos Quânticos , Sensibilidade e Especificidade , Vírus da Febre Suína Africana/isolamento & purificação , Vírus da Febre Suína Africana/imunologia , Vírus da Febre Suína Africana/genética , Animais , Febre Suína Africana/diagnóstico , Febre Suína Africana/virologia , Febre Suína Africana/imunologia , Suínos , Anticorpos Monoclonais/imunologia , Anticorpos Antivirais/imunologia , Cromatografia de Afinidade/métodos , Antígenos Virais/análise , Antígenos Virais/imunologia , Reprodutibilidade dos Testes , Fitas Reagentes
2.
Opt Express ; 31(2): 1737-1754, 2023 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-36785202

RESUMO

Incomplete optical distortion correction in VR HMDs leads to spatial dynamic distortion, which is a potential cause of VIMS. A perception experiment is designed for the investigation with three spatial distortion levels, with the subjective SSQ, five-scale VIMS level rating, and objective postural instability adopted as the evaluation metrics. The results show that the factor of spatial distortion level has a significant effect on all metrics increments (p<0.05). As the spatial distortion level drops off, the increments of VIMS symptoms decrease. The study highlights the importance of perfect spatial distortion correction in VR HMDs for eliminating the potential VIMS aggravation effect.

3.
J Sci Food Agric ; 101(11): 4578-4584, 2021 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-33474737

RESUMO

BACKGROUND: The resistance of proteins to gastrointestinal digestion contributes to their ability to act as allergens. Near-complete digestion of protein in wheat products is important with respect to avoiding the potential immunogenic effects of undigested peptides. Five modern US wheat classes (soft red winter, hard winter, hard red spring, club and durum) including 17 wheat varieties, as well as three ancient wheat classes (spelt, emmer and einkorn) including nine wheat varieties, were analyzed for kernel hardness (KH) and flour protein characteristics, in addition to in vitro protein digestibility (IVPD) of cooked flour, flour without albumins and globulins (FWOAG), gluten, albumins, and globulins, aiming to identify the factors influencing the protein digestibility of flour. RESULTS: IVPDs of flour, FWOAG, gluten and albumins of wheat varieties ranged from 86.5% to 92.3%, 85.8% to 90.3%, 90.6% to 94.6% and 74.8% to 85.1%, respectively. The IVPD of gluten was significantly higher than the IVPDs of flour and FWOAG, indicating that non-protein components substantially affect protein digestibility. Significant differences were observed in IVPDs of flour and albumins among eight wheat classes, but not in the IVPDs of FWOAG, gluten and globulins. There were apparent differences in undigested protein bands and intensities of wheat classes with low and high flour IVPDs. KH and albumin proportion exhibited negative and positive relationships, respectively, with flour IVPD. CONCLUSION: The results of the present study demonstrate that KH, non-protein components and albumin proportion have a major influence on protein digestion and need to be considered when developing wheat cultivars with higher protein digestibility.


Assuntos
Proteínas de Plantas/metabolismo , Triticum/metabolismo , Digestão , Farinha/análise , Humanos , Modelos Biológicos , Proteínas de Plantas/química , Proteólise , Sementes/química , Sementes/classificação , Sementes/metabolismo , Triticum/química , Triticum/classificação
4.
Rapid Commun Mass Spectrom ; 34(20): e8887, 2020 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-32656863

RESUMO

RATIONALE: Gas chromatography/mass spectrometry (GC/MS) and high-performance liquid chromatography/time-of-flight mass spectrometry (HPLC/TOF-MS) were used to separate and reveal the molecular characteristics of organic matter in low-rank coals. METHODS: Six soluble portions (SPs) were obtained by sequential thermal dissolution (TD) of two low-rank coals in the order of cyclohexane, acetone and methanol solvents at 300°C. Organic matter with different molecular characteristics were enriched in eachTD extract, which was further separated and analyzed by GC/MS and HPLC/TOF-MS using an electrospray ionization source in positive mode to obtain a comprehensive understanding of the structural composition of coals. RESULTS: Low polarity compounds like alkanes and arenes have a better solubility in cyclohexane. Phorone has the highest relative abundance in the acetone SPs, and the main compounds detected in the methanol SPs are alcohols and phenols. According to the data from HPLC/TOF-MS, most of the oxygen atoms are in the form of carbonyl and alkoxy groups. The nitrogen-containing compounds in SPs are mainly saturated aliphatic amines and pyridines. The sulfur-containing compounds mainly exist in the form of thioalkanes and thiophenes. CONCLUSIONS: Non-destructive methods were used to obtain soluble matter from coals, and different chromatographic and mass spectrometric techniques were used to separate and analyze the organic matter in coals. Detailed molecular structural information was obtained for the efficient and clean utilization of low-rank coals.

5.
J Sci Food Agric ; 100(10): 3850-3856, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32297322

RESUMO

BACKGROUND: The significance of high-molecular-weight glutenin subunits (HMW-GSs) and rye translocations, and their associations with gluten strength for hard wheat used for making bread has been understood well, but remains poorly understood for soft wheat used for making cookies. The influences of HMW-GSs and rye translocations on the dough-mixing properties and cookie-baking quality of soft wheat were investigated using 50 US eastern soft winter (ESW) wheat varieties possessing 14 predominant HMW-GS profiles. RESULTS: Glu-A1 and Glu-B1 loci only influenced dough-mixing properties significantly, whereas the Glu-D1 locus influenced both dough-mixing properties and cookie-baking quality significantly. The subunits 1, 7* + 8 and 5 + 10 at the Glu-A1, Glu-B1 and Glu-D1 loci, respectively, were associated with a long midline peak time, whereas only the rare subunits 2 + 121 at the Glu-D1 locus exhibited significant associations with improved cookie-baking quality of ESW wheat. The contributions of rye translocations to dough-mixing properties and cookie-baking quality depended on HMW-GS profiles. Three HMW-GS profiles (2*, 7 + 9, 2 + 121 ), (2*, 7 + 8, 2 + 121 ) and (1, 7 + 8, 2 + 121 ) were identified as being desirable for making large-diameter cookies. Flour protein content, lactic acid (LA), and sodium carbonate (SC) solvent retention capacities and softness equivalence were identified as effective predictors of cookie diameter and accounted for 79% of the variation in cookie diameter. CONCLUSION: Subunits 2 + 121 have significant associations with the protein characteristics and cookie-baking quality of soft wheat. The determination of HMW-GS composition would be an effective tool in soft-wheat breeding programs for quickly identifying and selecting acceptable breeding lines possessing desirable cookie-baking potential. Published 2020. This article is a U.S. Government work and is in the public domain in the USA.


Assuntos
Glutens/química , Secale/genética , Açúcares/química , Triticum/química , Pão/análise , Culinária , Farinha/análise , Manipulação de Alimentos , Glutens/genética , Melhoramento Vegetal , Subunidades Proteicas/química , Subunidades Proteicas/genética , Translocação Genética , Triticum/genética
6.
Rapid Commun Mass Spectrom ; 33(13): 1107-1113, 2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-30941795

RESUMO

RATIONALE: Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) was applied to the characterization of organic compounds in coal extracts at the molecular level. Large volumes of data obtained by FT-ICR MS were processed via statistical methods to extract valuable information on the molecular structures and compositions of organic compounds in coal. METHODS: A low-rank coal was subjected to ultrasonic extraction sequentially with six solvents to separate and enrich species with different molecular characteristics. Complex mass spectra of the six extracts were obtained by a FT-ICR MS system equipped with two ionization sources. Two multivariate statistical methods, hierarchical clustering analysis (HCA) and principle component analysis (PCA), were introduced to mine useful information from the complex MS data and visually exhibit comprehensive molecular details in coal extracts. RESULTS: Similarities and differences between the 17 MS data sets from six coal extracts ionized by different ion sources were visually exhibited in plots via data processing using HCA and PCA. For HCA, all of the identified compounds were divided into seven classes (CH, O, N, S, ON, OS, and NS), and detailed differences in the relative abundance were revealed. In addition, PCA discriminated the differences in molecular composition for organic compounds from the six extracts. CONCLUSIONS: Multivariate statistical analysis is a promising methodology which can interpret the chemical composition of coals and coal derivatives at the molecular level, especially for the analysis of multiple complex samples presenting in a single plot.

7.
Rapid Commun Mass Spectrom ; 32(16): 1462-1472, 2018 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-29740899

RESUMO

RATIONALE: Gas chromatography/mass spectrometry (GC/MS) is a routine and basic instrumental method for the analysis of complex coal conversion products in the chemical industry. To further enhance the practical potential of GC/MS in chemical industry, a tandem MS method for the selection of ion pairs applied in monitoring coal conversions was established using GC/quadrupole time-of-flight MS (GC/Q-TOF MS). The corresponding fragmentation pathways were explored and suitable ion pairs were screened. METHODS: Fourteen coal-related model compounds (CRMCs) were analyzed using GC/Q-TOF MS with different collision-induced dissociation (CID) energies (5-20 eV). The fragmentation pathways can offer a better understanding of chemical bond breaking, hydrogen transfer, rearrangement reactions and elimination of neutral fragments for CRMCs during the CID process. RESULTS: The precursor ions of aromatic hydrocarbons without alkyl chains were difficult to fragment with a CID energy of 20 eV. But aromatic hydrocarbons with branched chains were prone to fragment via the loss of alkyl chains and further fragmented through ring-opening reactions. Compared with the Calk Car bond, the Car Car bond was difficult to fragment due to its high bond dissociation energy. The existence of heteroatoms facilitated fragmentation that was conducive to the screening of ion pairs. CONCLUSIONS: The CID technique of GC/Q-TOF MS will contribute to studies on the organic composition of coals and to building monitoring methods for coal conversions via fragmentation and ion pair selection.

8.
J Huazhong Univ Sci Technolog Med Sci ; 33(3): 339-345, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23771657

RESUMO

Previous studies have shown that STAT3 plays a vital role in the genesis and progression of cancer. In this study, we investigated the relationship between the JAK2/STAT3 signalling pathway and germacrone-induced apoptosis in HepG2 cells. HepG2 cells were incubated with germacrone for 24 h, the protein expression of p-STAT3, STAT3, p-JAK2 and JAK2 was detected by Western Blotting, and RT-PCR was used to determine the expression of STAT3, p53, Bcl-2 and Bax at transcriptional levels. Besides that, HepG2 cells were pre-treated with AG490 or IL-6 for 2 h, and then incubated with germacrone for 24 h. The expression of p-JAK2, JAK2, p-STAT3, STAT3, p53, Bax and Bcl-2 was detected by Western blotting. The activity of HepG2 cells was tested by MTT assay. The apoptosis of HepG2 cells and levels of reactive oxygen species (ROS) were flow cytometrically measured. The results showed that germacrone exposure decreased p-STAT3 and p-JAK2 and regulated expression of p53 and Bcl-2 family members at the same time. Moreover, IL-6 enhanced the activation of the JAK2/STAT3 signalling pathway and therefore attenuated the germacrone-induced apoptosis. Suppression of JAK2/STAT3 signalling pathway by AG490, an inhibitor of JAK2, resulted in apoptosis and an increase in ROS in response to germacrone exposure. We therefore conclude that germacrone induces apoptosis through the JAK2/STAT3 signalling pathway.


Assuntos
Apoptose/efeitos dos fármacos , Medicamentos de Ervas Chinesas/administração & dosagem , Janus Quinase 2/metabolismo , Fator de Transcrição STAT3/metabolismo , Sesquiterpenos de Germacrano/administração & dosagem , Transdução de Sinais/efeitos dos fármacos , Relação Dose-Resposta a Droga , Células Hep G2 , Humanos
9.
J Nanosci Nanotechnol ; 12(9): 7280-3, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23035464

RESUMO

A facile one-pot route for the synthesis of monodisperse Ag nanocrystals with a narrow size distribution is described. Uniform Ag nanoparticles with the size of around 12 nm were obtained by reduction of AgNO3 in the presence of oleylamine and polymer polyvinylpyrrolidone (PVP) at low temperature. It is found that temperature has a significant effect on the sizes and the size distributions of the nanoparticles. Because irregular Ag nanoparticles are produced easily due to Ostwald ripening or kinetic control at both high temperature and low temperature, respectively, uniform nanocrystals can be obtained at an appropriate temperature (70 degrees C).


Assuntos
Nanopartículas Metálicas , Prata/química , Temperatura , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Espectrofotometria Ultravioleta
10.
Int Immunopharmacol ; 105: 108555, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35121223

RESUMO

Today, it is well-known that the interactions and secretion within the tumour are crucial to consider for cancer therapy. Some novel cancer therapy modalities such as immunotherapy or tumour vaccination therapy work based on the control of interactions within the tumour microenvironment (TME). It has been revealed that anti-cancer drugs or radiotherapy can modulate some interactions in favour of cancer therapy. However, they may induce some mechanisms to increase the resistance of cancer cells to therapy. Paclitaxel is known as the first approved herbal derived chemotherapy drug. Although the main known anti-cancer effect of paclitaxel is the inhibition of the cell cycle, today, it has been well known that paclitaxel may suppress the tumour via modulating several interactions in TME. Furthermore, paclitaxel may increase the expression of some tumour resistance drivers. This review aims to discuss the interactions within TME following treatment with paclitaxel. The effects of paclitaxel on the anti-tumour immunity, immunosuppressive cells, hypoxia, and also angiogenesis will be discussed. The targeting of these interactions may be interesting to increase therapy efficiency using the combination modalities.


Assuntos
Antineoplásicos , Neoplasias , Antineoplásicos/uso terapêutico , Humanos , Imunoterapia , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Paclitaxel/farmacologia , Paclitaxel/uso terapêutico , Microambiente Tumoral
11.
Plants (Basel) ; 11(22)2022 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-36432845

RESUMO

Wheat heading time is genetically controlled by phenology genes including vernalization (Vrn), photoperiod (Ppd) and earliness per se (Eps) genes. Characterization of the existing genetic variation in the phenology genes of wheat would provide breeding programs with valuable genetic resources necessary for the development of wheat varieties well-adapted to the local environment and early-maturing traits suitable for double-cropping system. One hundred forty-nine eastern U.S. soft winter (ESW) and 32 Korean winter (KW) wheat genotypes were characterized using molecular markers for Vrn, Ppd, Eps and reduced-height (Rht) genes, and phenotyped for heading date (HD) in the eastern U.S. region. The Ppd-D1 and Rht-D1 genes exhibited the highest genetic diversity in ESW and KW wheat, respectively. The genetic variations for HD of ESW wheat were largely contributed by Ppd-B1, Ppd-D1 and Vrn-D3 genes. The Rht-D1 gene largely contributed to the genetic variation for HD of KW wheat. KW wheat headed on average 14 days earlier than ESW wheat in each crop year, largely due to the presence of the one-copy vrn-A1 allele in the former. The development of early-maturing ESW wheat varieties could be achieved by selecting for the one-copy vrn-A1 and vrn-D3a alleles in combination with Ppd-B1a and Ppd-D1a photoperiod insensitive alleles.

12.
Talanta ; 250: 123686, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-35763952

RESUMO

In this work, we studied the preparation of a high-affinity antibody and its immunochromatographic applications to simultaneously identify capsaicin(LJJ), dihydrocapsaicin(HLJ), nordihydrocapsaicin, homodihydrocapsaicin, and other congeners in illegal cooking oil. We used dihydrocapsaicin hapten-conjugated carrier protein BSA as the immunogen according to the formaldehyde method, and conjugated capsaicin and OVA as the coated detection antigen according to the formaldehyde method. We subsequently screened and cloned a hybridoma cell line 2B3 with the highest affinity, which could stably secrete monoclonal antibodies against compounds in the capsaicin family. We then established a capsaicin indirect ELISA standard curve, which was fitted using the linear regression equation R = 0.9987, curve y = -2.3x + 0.2, and IC50 = 0.2 ng/mL. The cross-reaction rate for capsaicin was 100%, 116% for dihydrocapsaicin, 88% for homodihydrocapsaicin, and 94% for nordihydrocapsaicin. In the second application, we established a simple and accurate sample pretreatment method and a quantum dot-labeled test strip to quickly and quantitatively detect capsaicin family compounds in illegal cooking oil in 8 min. The average recovery rates for each spiked concentration were between 75% and 107.8%, and the coefficient of variation values for each spiked concentration were less than 15%. The high-affinity antibody we identified could simultaneously identify capsaicin, dihydrocapsaicin, nordihydrocapsaicin, homodihydrocapsaicin, and other congeners in illegal cooking oil, and the antibody could be quickly and accurately applied for the qualitative and quantitative detection of capsaicin family residues in illegal cooking oil.


Assuntos
Anticorpos Monoclonais , Capsaicina , Capsaicina/análogos & derivados , Capsaicina/análise , Proteínas de Transporte , Culinária , Formaldeído/análise , Haptenos/análise
13.
ACS Omega ; 7(40): 35496-35505, 2022 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-36249390

RESUMO

Increasing attention is currently obtained by the exploitation and utilization of unconventional energy sources globally. Jimusaer shale oil (JSO) was prepared by dry distillation from oil shale in Jimusaer, Xinjiang, China. Using n-heptane and toluene as solvents, saturate (SA), aromatic (AR), resin (RE), and asphaltene (AS) samples were produced from JSO. Samples were subsequently analyzed by elemental analysis (EA), thermogravimetric analysis (TG-DTG), infrared analysis (FT-IR), high-performance gel chromatography (GPC), and nuclear magnetic resonance (1H-NMR and 13C-NMR). In terms of basic properties, element content, classification of combustible minerals, and refining performance, JSO, which has a high H/C value, low carbon residue yield, low metal content, and excellent refining-processing performance, is considered a high-quality shale oil compared with the shale oil produced in other areas. The refining performance of JSO is even comparable with petroleum. According to column chromatography, the contents of SA, AR, RE, and AS in JSO are 54.32, 18.86, 25.81, and 1.01%, respectively. The results of FT-IR and NMR (1H-NMR and 13C-NMR) demonstrated that the chain alkane or aromatic cycloalkyl substituents of SA, AR, and RE decrease sequentially, while the number of aromatic rings and cycloalkane rings and the degree of condensation increase sequentially. These results indicate that the chain alkanes with a small number of cycloalkanes are the main component of SA. The AR and RE contain more thick-ring aromatic hydrocarbons. According to GPC, the molecular weight (M n) of JSO is 845 g·mol-1, and those of SA, AR, and RE are 702, 1107, and 2218 g·mol-1, respectively. The estimated molecular formulas (M af) of JSO, SA, AR, and RE, which were calculated based on the combined results of GPC and EA, are C57.91H115.60O1.38N0.79S0.04, C48.02H101.79O0.69N0.85S0.03, C76.96H137.16O1.08N1.87S0.09, and C156.24H247.75O1.46N4.42S0.32.

14.
Acta Biochim Biophys Sin (Shanghai) ; 43(4): 284-91, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21343162

RESUMO

Chloroplast transformation in wheat was achieved by bombardment of scutella from immature embryos and immature inflorescences, respectively. A wheat chloroplast site-specific expression vector, pBAGNRK, was constructed by placing an expression cassette containing neomycin phosphotransferase II (nptII) and green fluorescent protein (gfp) as selection and reporter genes, respectively, in the intergenic spacer between atpB and rbcL of wheat chloroplast genome. Integration of gfp gene in the plastome was identified by polymerase chain reaction (PCR) analysis and Southern blotting using gfp gene as a probe. Expression of GFP protein was examined by western blot. Three positive transformants were obtained and the Southern blot of partial fragment of atpB and rbcL (targeting site) probes verified that one of them was homoplasmic. Stable expression of GFP fluorescence was confirmed by confocal microscopy in the leaf tissues from T(1) progeny seedlings. PCR analysis of gfp gene also confirmed the inheritance of transgene in the T(1) progeny. These results strengthen the feasibility of wheat chloroplast transformation and also give a novel method for the introduction of important agronomic traits in wheat through chloroplast transformation.


Assuntos
Cloroplastos/genética , Inflorescência/genética , Estruturas Vegetais/genética , Triticum/genética , Southern Blotting , Western Blotting , Cloroplastos/metabolismo , DNA de Cloroplastos/genética , Vetores Genéticos/genética , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Inflorescência/metabolismo , Canamicina Quinase/genética , Microscopia Confocal , Folhas de Planta/genética , Folhas de Planta/metabolismo , Estruturas Vegetais/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Reação em Cadeia da Polimerase , Transformação Genética , Transgenes/genética , Triticum/metabolismo
15.
ACS Omega ; 6(12): 8288-8296, 2021 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-33817488

RESUMO

Hydrodynamic cavitation (HC) of aromatic hydrocarbons present in creosote oil obtained from coal tar in the presence of 0.3% (w/w) Ni2+ as an inducer increased its naphthalene and phenanthrene content by 7.3 and 2.6%, respectively. An optimal procedure was developed based on the use of an upstream pressure of 2.6 MPa, an immersing height (H) for the cavitator of 105 mm, 10% H2O content, use of a NiSO4 solution at pH 4.0, and an operating temperature of 75 °C. Enrichment of the naphthalene and phenanthrene components is caused by hydroxyl and hydrogen radicals generated in the reaction inducing aromatic components to undergo a series of radical demethylation/methylation reactions to produce new product ratios. The observed increases in naphthalene and phenanthrene content using Ni2+ as a radical inducer are in contrast with the previous results using Fe2+ under similar conditions, which led to the enrichment of the acenaphthalene fraction of creosote oil.

16.
ACS Omega ; 6(25): 16373-16380, 2021 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-34235308

RESUMO

Three Ni-Al2O3 catalysts were prepared, in planetary ball-milling machine, by the mechanochemical method with Al(NO3)3·9H2O as the aluminum precursor, (NH4)2CO3 as the precipitant, and Ni(NO3)2·6H2O, NiCl2·6H2O, and Ni(CH3COO)2·4H2O as nickel precursors (the corresponding catalysts were labeled as Ni-NO, Ni-Cl, and Ni-Ac). The prepared catalysts were characterized by X-ray diffraction (XRD), temperature-programmed reduction (H2-TPR), and N2 adsorption-desorption technologies, and CO methanation performance evaluation was carried out for the catalysts. Results showed that the catalyst with Ni(NO3)2·6H2O as the precursor presented good Ni dispersibility and a small Ni grain size of 6.80 nm. CO conversion, CH4 selectivity, and yield of the catalyst were as high as 78.8, 87.9, and 69.8%, respectively. Carbon deposition analysis from temperature-programmed hydrogenation (TPH) characterization showed that the H2 consumption peak area of the three samples followed the order: Ni-NO (2886.66 au) < Ni-Cl (4389.97 au) < Ni-Ac (5721.65 au), indicating that the Ni-NO catalyst showed higher resistance to carbon deposition, which might be due to its small Ni grain size.

17.
ACS Omega ; 6(25): 16381-16390, 2021 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-34235309

RESUMO

Modified Ni-Al2O3 catalysts with Ca, Co, and Ce species as promoters were prepared by the combustion method, and the structure, morphology, reduction characteristic, and CO2-CH4 reforming of the catalysts were discussed by X-ray diffraction (XRD), H2-temperature-programmed reduction (H2-TPR), energy-dispersive X-ray (EDX) mapping, NH3-temperature-programmed desorption (NH3-TPD), N2 adsorption-desorption, thermogravimetric-differential thermal analysis (TG-DTG), and temperature-programmed hydrogenation (TPH) methods. The crystal size of Ni on Ca-Ni-Al2O3 was 16.97 nm, and the active component and additive were distributed well in the catalyst. Co-Ni-Al2O3 presented a surface area of 65.70 m2·g-1 and a pore diameter of 161.60 nm. Ce-Ni-Al2O3 showed relatively stable nickel-aluminum spinel (NiAl2O4), which could not be easily reduced to the active component Ni. Evaluation results demonstrated that the performance of the catalysts followed the order Co-Ni-Al2O3 > Ca-Ni-Al2O3 > Ni-Al2O3 > Ce-Ni-Al2O3. Carbon deposition analysis showed that the carbon resistance of Ca-Ni-Al2O3 was poor and graphitic carbon was generated on the catalyst. However, Ce-Ni-Al2O3 showed less carbon deposition, which might have resulted from the lower activity of the catalyst.

18.
ACS Omega ; 6(23): 14765-14773, 2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-34151058

RESUMO

N-methyl-2-pyrrolidone (NMP), pyridine (Py), tetrahydrofuran (THF), and tetralin (THN) were used to swell Hefeng acid-washed bituminous coal (HBCAC). The swelling effect on HBCAC by each solvent is different, among which NMP presented well swelling performance, with a swelling degree of 2.11. FTIR results showed that acid washing and swelling processes presented a marginal effect on HBC, and there was no damage to the macromolecule structure of the coal. TG-DTG profiles of the swollen coals illustrated that the total weight loss of each sample was lower than that of the acid-washing one, while the temperature of the maximum weight loss rate peak was almost unchanged, around 445 °C. Extract yield by methanol followed the order of HBCAC > HBC > HBCAC-NMP (swelled by NMP), showing that acid washing promoted the methanol extraction process, with a higher extract yield of 3.21%, which is twice that of HBC (1.66%).

19.
ACS Omega ; 5(27): 16789-16795, 2020 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-32685847

RESUMO

Iron-supported catalysts exhibit good catalytic performance in direct coal liquefaction (DCL), but the effect of the carrier on the performance of the composite catalyst is unclear. In this paper, a simple solid-state synthesis strategy for the preparation of coal-loaded Fe3O4 nanoparticles (Fe3O4/Coal) and the hydrochloric acid treatment of coal-loaded Fe3O4 nanoparticles (Fe3O4/Coal-HCl) is presented. The resulting composite was used as a catalyst for DCL. The effects of supports on the structure and performance of iron-supported catalysts have been illustrated. After the acid pretreatment of the catalyst carrier coal, the surface structure and functional groups changed, which affected the aggregation morphology of the Fe3O4 active component. The Fe3O4/Coal-HCl catalyst improved the catalytic performance of DCL with conversion and oil yield of 98.02 and 49.96 wt %, respectively. The result shows that pretreatment can be an effective way to modify the surface of the catalyst carrier coals, thereby further improving the catalytic performance of composites. The iron-based composites prepared by the solid-state route show great potential as supported catalysts in DCL.

20.
RSC Adv ; 10(10): 5516-5524, 2020 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-35497417

RESUMO

Three commercial Ni-Al alloys formed by a vacuum atomization method (NAV), atmospheric atomization method (NAA) and high-temperature melting method (NAH) were leached by 10 wt% NaOH solution to prepare three RANEY®-Ni catalysts (RNAV, RNAA and RNAH, correspondingly). The effects of a forming process on the structure of Ni-Al alloys and the corresponding RANEY®-Ni catalysts were investigated via XRD, XPS, SEM, TEM, NH3-TPD, N2 adsorption-desorption and EDX-mapping studies. Also, the as-prepared RANEY®-Ni catalysts were evaluated via the hydrogenation of 1,4-butenediol (BED) to produce 1,4-butanediol (BDO). The results showed that the specific surface areas and surface morphologies of the Ni-Al alloys present significant differences. Meanwhile, the RNAA sample presented a comparatively regular morphology, similar to a small piece of sugar cane. The weak and medium acid peak areas of the RNAA catalyst were lower than those of the other samples. RNAV showed higher weak and medium acid peak areas, demonstrating the higher number of acid centers on the surface of the catalyst. The surface of the RNAA catalyst obtained from NAA contained more active component-Ni, about 90 wt% on the surface, and the specific surface area of the sample was 75 times that of its precursor Ni-Al alloy powder (NAA). The evaluation results present that the RNAA catalyst shows better hydrogenation performance, with BED conversion of 100%, both BDO selectivity and yield of 46.11%.

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