Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 36
Filtrar
1.
Drug Dev Ind Pharm ; 49(9): 551-558, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37647269

RESUMO

OBJECTIVES: Sub-visible particle, or particulate matter, is an important indicator in the safety assessment of clinical infusions. The present study aims to evaluate the effect of the packaging formats of antibiotic on the distribution of sub-visible particles in the small particle size range (<10 µm), to provide evidence for explanation to clinical adverse reactions and guidelines for rational drug use. METHODS: The conventional light blockage and the single particle optical sensing (SPOS) technology were applied to determine the size distribution of the sub-visible particles in the redissolved injections in different packages (dual-chamber bag and vial) from different manufacturers. In order to verify our hypothesis, the influences of active pharmaceutical ingredient (API) and solvent were controlled. Further, scanning electron microscopy (SEM) was utilized to observe the morphological characteristics of sub-visible particles from different package injections. RESULTS: After redissolving, the small-sized sub-visible particles (<10 µm) in the solution of injectable powder packaged in the dual-chamber bag were significantly lower than that of the conventional injectable powder packaged in the vial, and the difference remained significant after controlling for API. The results observed by SEM also supported the differences in the amount of particulate matter between the two packaging formats, showing a higher number of sub-visible particles from sodium chloride dissolved preparations packed in vails, with irregular shapes. CONCLUSION: In our study, the differences in the distribution of sub-visible particles were mainly attributed to the packaging formats. The dual-chamber bag injection might be an effective alternative to reduce the adverse reactions caused by sub-visible particles.


Assuntos
Embalagem de Medicamentos , Material Particulado , Pós , Tamanho da Partícula , Injeções
2.
Biomed Chromatogr ; 36(9): e5419, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35638105

RESUMO

This study developed a UPLC-MS/MS method to detect isoscoparin in mouse blood, determined the pharmacokinetics of isoscoparin in mice after intravenous (5 mg/kg) and intragastric (20 mg/kg) administration, and calculated the absolute bioavailability. A HSS T3 column was used for separation, and the column temperature was set at 40°C. The mobile phases were acetonitrile and 0.1% formic acid, and the gradient elution procedure was used. The blood sample was treated with protein precipitant with acetonitrile-methanol (9:1, v/v). Multiple reaction monitoring mode was used for quantitative analysis in electrospray positive-ion mode. It showed a good linear relationship in the range of 1-4000 ng/mL (r > 0.998); the intra-day and inter-day precision was <12%, and the accuracy was 86-112%. The recovery was >68%, and the matrix effect was 86-90%. The half-life of isoscoparin was relatively short in mice, and the bioavailability was 2.6%. The developed UPLC-MS/MS method was rapid, sensitive, and suitable for the pharmacokinetics of isoscoparin in mice.


Assuntos
Espectrometria de Massas em Tandem , Acetonitrilas , Animais , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia Líquida/métodos , Camundongos , Ratos , Ratos Sprague-Dawley , Reprodutibilidade dos Testes , Espectrometria de Massas em Tandem/métodos
3.
Int J Mol Sci ; 23(19)2022 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-36232661

RESUMO

The adsorption separation and extraction of low-concentration boron from salt-lake brine have great significance. Magnetic separation avoids the problem of adsorbent granulation and improves the usage efficiency. The silicon-based adsorbents have attracted interest due to their superior acid and alkali resistance, in which polyhydroxy graphene enhances the adsorption of boron ions. Herein different boron adsorbents, derived by magnetic separation, were developed and characterized by SEM, TEM, XPS, VSM, FT-IR, and XRD analysis. The adsorption-desorption performance of boron adsorbents with different compositions was evaluated. The isotherms and kinetics parameters of the boron extraction were evaluated based on adsorption-desorption tests. The graphene-based magnetic adsorbent (Go-Fe3O4@SiO2@mSiO2-Glu) registered a high boron adsorption capacity of 23.90 mg/g at pH = 9 in the boron solution and 24.84 mg/g for East Taigener salt-lake brine. The Na+, Mg2+, Ca2+, and Cl- ions have little interference with the boron adsorption. The adsorbents exhibit magnetic separation performance and good cycle life. The results showed that acid-alkali desorption solution has little effect on the adsorbents, and the composite of graphene enhances the adsorption of boron ions. The adsorbents developed in this study are promising to recover boron from low-concentration boron-containing salt-lake brines.


Assuntos
Grafite , Poluentes Químicos da Água , Adsorção , Álcalis , Boro , Glucose , Grafite/química , Cetoácidos , Lagos , Fenômenos Magnéticos , Sais , Silício , Dióxido de Silício/química , Espectroscopia de Infravermelho com Transformada de Fourier
4.
Angew Chem Int Ed Engl ; 61(15): e202116404, 2022 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-35156284

RESUMO

Heat-induced blueshift (HIB) observed in many luminescent materials is a puzzling phenomenon that has remained unexplained for decades. By using the high-throughput first-principles calculations and energy-screening techniques, we generated a number of model structures for five phosphors, RbLi[Li3 SiO4 ]2 :Eu2+ , Na[Li3 SiO4 ]:Eu2+ , K[Li3 SiO4 ]:Eu2+ , Sr[LiAl3 N4 ]:Eu2+ , and Ca[LiAl3 N4 ]:Eu2+ . Our analyses suggest, to a first approximation, a logarithmic energy dependence on the nearest distance between the dopant and the metal-cation vacancy. By identifying the 5 d → 4 f transition energies from the electronic structures calculated for the screened model structures, we show that the vibration of the Eu2+ ion lying in an asymmetric and anharmonic potential well couples with the electronic states, leading to their HIB phenomena.

5.
Int J Mol Sci ; 22(5)2021 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-33669030

RESUMO

Potato tuber dormancy is critical for the post-harvest quality. Snakin/Gibberellic Acid Stimulated in Arabidopsis (GASA) family genes are involved in the plants' defense against pathogens and in growth and development, but the effect of Snakin-2 (SN2) on tuber dormancy and sprouting is largely unknown. In this study, a transgenic approach was applied to manipulate the expression level of SN2 in tubers, and it demonstrated that StSN2 significantly controlled tuber sprouting, and silencing StSN2 resulted in a release of dormancy and overexpressing tubers showed a longer dormant period than that of the control. Further analyses revealed that the decrease expression level accelerated skin cracking and water loss. Metabolite analyses revealed that StSN2 significantly down-regulated the accumulation of lignin precursors in the periderm, and the change of lignin content was documented, a finding which was consistent with the precursors' level. Subsequently, proteomics found that cinnamyl alcohol dehydrogenase (CAD), caffeic acid O-methyltransferase (COMT) and peroxidase (Prx), the key proteins for lignin synthesis, were significantly up-regulated in silencing lines, and gene expression and enzyme activity analyses also supported this effect. Interestingly, we found that StSN2 physically interacts with three peroxidases catalyzing the oxidation and polymerization of lignin. In addition, SN2 altered the hydrogen peroxide (H2O2) content and the activities of superoxide dismutase (SOD) and catalase (CAT). These results suggest that StSN2 negatively regulates lignin biosynthesis and H2O2 accumulation, and ultimately inhibits the sprouting of potato tubers.


Assuntos
Cisteína/metabolismo , Peróxido de Hidrogênio/metabolismo , Lignina/biossíntese , Proteínas de Plantas/metabolismo , Tubérculos/metabolismo , Solanum tuberosum/metabolismo , Oxirredutases do Álcool/metabolismo , Catalase/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Inativação Gênica , Lignina/metabolismo , Peroxidase/metabolismo , Dormência de Plantas/genética , Proteínas de Plantas/genética , Caules de Planta/citologia , Caules de Planta/genética , Caules de Planta/metabolismo , Tubérculos/genética , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Ligação Proteica , Proteína O-Metiltransferase/metabolismo , Proteômica , Plântula/citologia , Plântula/genética , Plântula/metabolismo , Solanum tuberosum/enzimologia , Solanum tuberosum/genética , Superóxido Dismutase-1/metabolismo
6.
Int J Mol Sci ; 21(7)2020 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-32268484

RESUMO

Alligator weed is reported to have a strong ability to adapt to potassium deficiency (LK) stress. Leaves are the primary organs responsible for photosynthesis of plants. However, quantitative proteomic changes in alligator weed leaves in response to LK stress are largely unknown. In this study, we investigated the physiological and proteomic changes in leaves of alligator weed under LK stress. We found that chloroplast and mesophyll cell contents in palisade tissue increased, and that the total chlorophyll content, superoxide dismutase (SOD) activity and net photosynthetic rate (PN) increased after 15 day of LK treatment, but the soluble protein content decreased. Quantitative proteomic analysis suggested that a total of 119 proteins were differentially abundant proteins (DAPs). KEGG analysis suggested that most represented DAPs were associated with secondary metabolism, the stress response, photosynthesis, protein synthesis, and degradation pathway. The proteomic results were verified using parallel reaction monitoring mass spectrometry (PRM-MS) analysis and quantitative real-time PCR (qRT-PCR)assays. Additional research suggested that overexpression of cationic peroxidase 1 of alligator weed (ApCPX1) in tobacco increased LK tolerance. The seed germination rate, peroxidase (POD) activity, and K+ content increased, and the hydrogen peroxide (H2O2) content decreased in the three transgenic tobacco lines after LK stress. The number of root hairs of the transgenic line was significantly higher than that of WT, and net K efflux rates were severely decreased in the transgenic line under LK stress. These results confirmed that ApCPX1 played positive roles in low-K+ signal sensing. These results provide valuable information on the adaptive mechanisms in leaves of alligator weed under LK stress and will help identify vital functional genes to apply to the molecular breeding of LK-tolerant plants in the future.


Assuntos
Peroxidases/metabolismo , Folhas de Planta/metabolismo , Plantas Daninhas/metabolismo , Deficiência de Potássio/metabolismo , Proteoma , Proteômica , Estresse Fisiológico , Animais , Cromatografia Líquida de Alta Pressão , Biologia Computacional/métodos , Ontologia Genética , Fenótipo , Proteômica/métodos , Espectrometria de Massas em Tandem
7.
Int J Mol Sci ; 18(11)2017 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-29084178

RESUMO

Sprouting regulation in potato tubers is important for improving commercial value and producing new plants. Camphor shows flexible inhibition of tuber sprouting and prolongs the storage period of potato, but its underlying mechanism remains unknown. The results of the present study suggest that camphor inhibition caused bud growth deformities and necrosis, but after moving to more ventilated conditions, new sprouts grew from the bud eye of the tuber. Subsequently, the sucrose and fructose contents as well as polyphenol oxidase (PPO) activity were assessed after camphor inhibition. Transcription and proteomics data from dormancy (D), sprouting (S), camphor inhibition (C), and recovery sprouting (R) samples showed changes in the expression levels of approximately 4000 transcripts, and 700 proteins showed different abundances. KEGG (Kyoto encyclopaedia of genes and genomes) pathway analysis of the transcription levels indicated that phytohormone synthesis and signal transduction play important roles in tuber sprouting. Camphor inhibited these processes, particularly for gibberellic acid, brassinosteroids, and ethylene, leading to dysregulation of physiological processes such as cutin, suberine and wax biosynthesis, fatty acid elongation, phenylpropanoid biosynthesis, and starch and sucrose metabolism, resulting in bud necrosis and prolonged storage periods. The KEGG pathway correlation between transcripts and proteins revealed that terpenoid backbone biosynthesis and plant-pathogen interaction pathways showed significant differences in D vs. S samples, but 13 pathways were remarkably different in the D vs. C groups, as camphor inhibition significantly increased both the transcription levels and protein abundance of pathogenesis-related protein PR-10a (or STH-2), the pathogenesis-related P2-like precursor protein, and the kirola-like protein as compared to sprouting. In recovery sprouting, these genes and proteins were decreased at both the transcriptional level and in protein abundance. It was important to find that the inhibitory effect of camphor on potato tuber sprout was reversible, revealing the action mechanism was similar to resistance to pathogen infection. The present study provides a theoretical basis for the application of camphor in prolonging seed potato storage.


Assuntos
Cânfora/farmacologia , Perfilação da Expressão Gênica , Tubérculos/efeitos dos fármacos , Tubérculos/fisiologia , Proteômica , Solanum tuberosum/efeitos dos fármacos , Solanum tuberosum/fisiologia , Biologia Computacional/métodos , Frutose/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Redes Reguladoras de Genes , Fenótipo , Proteoma , Proteômica/métodos , Transdução de Sinais , Solanum tuberosum/citologia , Sacarose/metabolismo , Transcriptoma
8.
Biol Pharm Bull ; 38(7): 1049-53, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26133715

RESUMO

Paraquat is one of the most widely used herbicides in the world and is highly toxic to humans and animals. In this study, we developed a serum metabolomic method based on GC/MS to evaluate the effects of acute paraquat poisoning on rats. Pattern recognition analysis, including both principal component analysis and partial least squares-discriminate analysis revealed that acute paraquat poisoning induced metabolic perturbations. Compared with the control group, the level of octadecanoic acid, L-serine, L-threonine, L-valine, and glycerol in the acute paraquat poisoning group (36 mg/kg) increased, while the levels of hexadecanoic acid, D-galactose, and decanoic acid decreased. These findings provide an overview of systematic responses to paraquat exposure and metabolomic insight into the toxicological mechanism of paraquat. Our results indicate that metabolomic methods based on GC/MS may be useful to elucidate the mechanism of acute paraquat poisoning through the exploration of biomarkers.


Assuntos
Herbicidas/intoxicação , Metaboloma/efeitos dos fármacos , Paraquat/intoxicação , Aminoácidos/sangue , Animais , Biomarcadores/sangue , Galactose/sangue , Metabolismo dos Lipídeos/efeitos dos fármacos , Masculino , Metabolômica , Ratos Sprague-Dawley
9.
Biomed Chromatogr ; 29(12): 1805-10, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26033449

RESUMO

In this work, a sensitive and selective ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for determination of hupehenine in rat plasma was developed and validated. After addition of imperialine as an internal standard (IS), protein precipitation by acetonitrile-methanol (9:1, v/v) was used to prepare samples. Chromatographic separation was achieved on a UPLC BEH C18 column (2.1 × 100 mm, 1.7 µm) with 0.1% formic acid and acetonitrile as the mobile phase with gradient elution. An electrospray ionization source was applied and operated in positive ion mode; multiple reaction monitoring mode was used for quantification using target fragment ions m/z 416.3 → 98.0 for hupehenine, and m/z 430.3 → 138.2 for IS. Calibration plots were linear throughout the range 2-2000 ng/mL for hupehenine in rat plasma. Mean recoveries of hupehenine in rat plasma ranged from 92.5 to 97.3%. Relative standard deviations of intra-day and inter-day precision were both <6%. The accuracy of the method was between 92.7 and 107.4%. The method was successfully applied to a pharmacokinetic study of hupehenine after either oral or intravenous administration. For the first time, the bioavailability of hupehenine was reported as 13.4%.


Assuntos
Alcaloides/sangue , Alcaloides/farmacocinética , Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas em Tandem/métodos , Alcaloides/química , Animais , Modelos Lineares , Masculino , Ratos , Ratos Sprague-Dawley , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
10.
ACS Omega ; 9(29): 31803-31813, 2024 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-39072068

RESUMO

Co-pyrolysis of coal and biomass is an efficient way to utilize resources. This study investigates the co-pyrolysis behavior and kinetics of coal and biomass using thermogravimetric analysis (TGA) and TG-FTIR. Co-pyrolysis of coal and biomass exhibits a synergistic effect. When the biomass is 25%, the weight loss increases, showing a positive synergistic effect. When the biomass is 50%, it exhibits a negative synergistic effect. Increasing the heating rate can promote the generation of a synergistic effect. Co-pyrolysis involves two central pyrolysis stages: stage III (250-380 °C) and stage IV (380-550 °C). Friedman, FWO, KAS, and STA methods are used to calculate the activation energy for stages III and IV. The activation energy (E α) for co-pyrolysis is higher than that for coal or biomass pyrolysis alone. A positive synergistic effect is observed in stage III, while a negative synergistic effect is noted in stage IV. The master curve method determines an accurate reaction order (n) and pre-exponential factor (A) value of Coal75-Bio25. In stage III, E α = 238.81 kJ/mol, n = 2.4, A = 1.30 × 1021 s-1. In stage IV, E α = 37 8.01 kJ/mol, n = 4.0, A = 1.10 × 1027 s-1. The kinetic parameters in stage IV are significantly higher than those in stage III. TG-FTIR is used to analyze the synergistic effect of co-pyrolysis. Compared with coal and biomass pyrolysis separately, the Coal75-Bio25 pyrolysis process releases less CO2 and more CH4. These findings support the synergistic effect of coal and biomass during co-pyrolysis.

11.
Carbohydr Polym ; 331: 121853, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38388035

RESUMO

Stability of displacement front is of great importance in the immiscible fluid displacement for enhancing oil recovery. Here, a CO2-strenghened assembly approach is demonstrated for the fabrication of highly jammed CNSs (cellulose nanocrystal surfactants) with EPD (N'-ethylpropane-1,3-diamine) and TOCNC (TEMPO oxidized cellulose nanocrystal), which produce a structured film at the oil-water interface to counteract the capillary force, and thus governing the local displacing pattern. In this approach, EPD molecules can be deeply protonated in the presence of CO2, favoring their binding forces with TOCNC at the interface to produce more CNSs. Meanwhile, the strong intermolecular attractions among CO2-bearing CNSs promote to form a striped interfacial film with both the close-packed rod-like arrays in horizontal and the multi-layer in lateral. Further, the CNSs-based film confers with a high strength and elasticity can reduce the capillary force by 87 % in micro-channels, yielding a smooth water-to-oil displacement front, which markedly enhances the oil recovery by 20.6 % compared to the surfactant-only flooding. This self-assembly strategy has a great implication in eco-friendly and cost-effective applications, such as enhanced oil recovery, CO2 geo-sequestration, and water infiltration.

12.
Asian J Pharm Sci ; 19(3): 100913, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38903129

RESUMO

Flare and multiple recurrences pose significant challenges in gouty arthritis. Traditional treatments provide temporary relief from inflammation but fail to promptly alleviate patient pain or effectively prevent subsequent recurrences. It should also be noted that both anti-inflammation and metabolism of uric acid are necessary for gouty arthritis, calling for therapeutic systems to achieve these two goals simultaneously. In this study, we propose a biomimetic integrated nanozyme, HMPB-Pt@MM, comprising platinum nanozyme and hollow Prussian blue. It demonstrates anti-inflammatory properties by eliminating reactive oxygen species and reducing infiltration of inflammatory macrophages. Additionally, it rapidly targets inflamed ankles through the camouflage of macrophage membranes. Furthermore, HMPB-Pt@MM exhibits urate oxidase-like capabilities, continuously metabolizing locally elevated uric acid concentrations, ultimately inhibiting multiple recurrences of gouty arthritis. In summary, HMPB-Pt@MM integrates ROS clearance with uric acid metabolism, offering a promising platform for the treatment of gouty arthritis.

13.
Sci Total Environ ; 926: 172024, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38547989

RESUMO

The use of reclaimed water for urban river replenishment has raised concerns regarding its impact on water quality and aquatic ecosystems. This study aims to reveal the improvements seen in an urban river undergoing a practical water eco-remediation after being replenished with reclaimed water. A one-year monitoring of water quality, phytoplankton, and zooplankton was carried out in Dongsha River undergoing eco-remediation in Beijing, China. The results showed that compared to the unrestored river, the concentrations of COD, NH4+-N, TP, and TN decreased by 28.22 ± 7.88 %, 40.24 ± 11.77 %, 44.17 ± 17.29 %, and 28.66 ± 10.39 % in the restoration project area, respectively. The concentration of Chlorophyll-a in the restoration area was maintained below 40 µg/L. During summer, when algal growth is vigorous, the density of Cyanophyta in the unrestored river decreased from 46.84 × 104cells/L to 16.32 × 104cells/L in the restored area, while that of Chlorophyta decreased from 41.61 × 104cells/L to 11.87 × 104cells/L, a reduction of 65.16 % and 71.47 %, respectively. The dominant phytoplankton species were replaced with Bacillariophyta, such as Synedra sp. and Nitzschia sp., indicating that the restoration of aquatic plants reduces the risk of Cyanophyta blooms. Zooplankton species also changed in the restoration area, especially during summer. The density of pollution-tolerant Rotifer and Protozoa decreased by 31.06 % and 27.22 %, while the density of clean water indicating Cladocera increased by 101.19 %. We further calculated the diversity and evenness index of phytoplankton and zooplankton within and outside the restoration area. The results showed that the Shannon-Weaver index for phytoplankton and zooplankton in the restoration area was 2.1 and 1.91, which was higher than those in the river (1.84 and 1.82). This further confirmed that aquatic plant restoration has positive effects. This study can provide a practical reference and theoretical basis for the implementation of water ecological restoration projects in other reclaimed water rivers in China.


Assuntos
Cianobactérias , Diatomáceas , Animais , Qualidade da Água , Pequim , Ecossistema , Rios , China , Fitoplâncton , Zooplâncton , Monitoramento Ambiental
14.
Zhongguo Zhong Yao Za Zhi ; 38(8): 1198-202, 2013 Apr.
Artigo em Zh | MEDLINE | ID: mdl-23944035

RESUMO

The alkaloids in Zanthoxylum nitidum were identified by HPLC-DAD/ESI-Q-TOF-MS. Separation was performed on a Hanbon C18 column with acetonitrile (with 0.1% formic acid) and water(with 0.1% formic acid) as mobile phase. Based on the high-resolution mass information, MS/MS fragmentation behaviors and chemical components from literatures, 48 components were identified or tentatively characterized including 6 new compounds. This work could be useful for the quality control and further studies of the plant.


Assuntos
Alcaloides/química , Zanthoxylum/química , Cromatografia Líquida de Alta Pressão , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
15.
ACS Appl Mater Interfaces ; 15(33): 39883-39895, 2023 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-37578297

RESUMO

Hydrogels have been widely applied to the water shutoff in oilfields due to their excellent three-dimensional network and thermal and physicochemical stability, and it is still a huge challenge to develop new hydrogels with simple preparation, low cost, and high mechanical performance that can meet the requirements of practical applications. Herein, we devised a simple and universal manufacturing method for regulating the hydrogen bonds between poly(vinyl alcohol) (PVA) and cellulose nanofibers (CNF) via the water-diffusion action, thus fabricating a physically tough PVA-CNF hydrogel for the in situ water shutoff. This method allowed the polymer chains to strengthen the molecular interactions between polymers upon replacing with water (a poor solvent) to regulate the cross-linking structure, characterizing by the nano-crystallinity domains and fibrillar segments, which also accounted for the thermal stability, extraordinary elasticity, high stretchability, and toughness of PVA-CNF hydrogel. Further, the obtained PVA-CNF hydrogel exhibited superb plugging performance, that is, the breakthrough pressure gradient could reach 71.56 MPa·m-1, surpassing all currently reported gelling water shutoff agents. This water-induced in situ hydrogelation made it well suited as a water shutoff agent in oilfields and may provide a promising strategy to fabricate mechanically robust smart materials for the water shutoff projects with low cost, simple processing, and high efficiency.

16.
Materials (Basel) ; 16(10)2023 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-37241241

RESUMO

Porous carbon nanofibers are commonly used for adsorption processes owing to their high specific surface area and rich pore structure. However, the poor mechanical properties of polyacrylonitrile (PAN)-based porous carbon nanofibers have limited their applications. Herein, we introduced solid waste-derived oxidized coal liquefaction residue (OCLR) into PAN-based nanofibers to obtain activated reinforced porous carbon nanofibers (ARCNF) with enhanced mechanical properties and regeneration for efficient adsorption of organic dyes in wastewater. This study examined the effects of contact time, concentration, temperature, pH, and salinity on the adsorption capacity. The adsorption processes of the dyes in ARCNF are appropriately described by the pseudo-second-order kinetic model. The maximum adsorption capacity for malachite green (MG) on ARCNF is 2712.84 mg g-1 according to the fitted parameters of the Langmuir model. Adsorption thermodynamics indicated that the adsorptions of the five dyes are spontaneous and endothermic processes. In addition, ARCNF have good regenerative performance, and the adsorption capacity of MG is still higher than 76% after 5 adsorption-desorption cycles. Our prepared ARCNF can efficiently adsorb organic dyes in wastewater, reducing the pollution to the environment and providing a new idea for solid waste recycling and water treatment.

17.
Artigo em Inglês | MEDLINE | ID: mdl-36883961

RESUMO

Polymer gels can be effectively applied to plug fractured reservoirs and carbonate cave strata. Herein, polyvinyl alcohol (PVA), acrylamide, and 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) were used as raw materials to prepare interpenetrating three-dimensional network polymer gels using formation saltwater in the Tahe oilfield (Tarim Basin, NW China) as a solvent. The effect of AMPS concentration on the gelation properties of PVA in high-temperature formation saltwater was analyzed. Further, the effect of PVA concentration on the strength and viscoelastic properties of polymer gel was studied. The polymer gel could retain stable continuous entanglement at 130 °C and exhibited satisfactory thermal stability. Continuous step oscillation frequency tests showed that it exhibited an excellent self-healing performance. Scanning electron microscopy images of the simulated core by gel plugging showed that the polymer gel could firmly fill the porous media, indicating that the polymer gel exhibits excellent application prospects in oil and gas reservoirs under high-temperature and high-salinity conditions.

18.
Carbohydr Polym ; 311: 120759, 2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37028878

RESUMO

The injection of CO2 into oil reservoirs to enhance oil recovery (EOR) has become a widely accepted and effective technical method, which, however, remains subject to the gas channeling caused by the reservoir fractures. Herein, this work developed a novel plugging gel combining excellent mechanical properties, fatigue resistance, elastic and self-healing properties for the CO2 shutoff purpose. This gel consisting of grafted nanocellulose and polymer network was synthesized via a free-radical polymerization, and reinforced by using Fe3+ to cross-link the two networks. The as-prepared PAA-TOCNF-Fe3+ gel has a stress of 1.03 MPa and a high strain of 1491 %, and self-heals to its original 98 % in stress and 96 % in strain after rupture, respectively. The introduce of TOCNF/Fe3+ improves the excellent energy dissipation and self-healing via the synergy effect of dynamical coordination bonds and hydrogen bonds. Further, the PAA-TOCNF-Fe3+ gel is both flexible and high-strength in plugging the multi-round CO2 injection, during which the CO2 breakthrough pressure is above 9.9 MPa/m, the plugging efficiency exceeds 96 %, and the self-healing rate is larger than 90 %. Given that above, this gel shows a great potential to plug the high-pressure CO2 flow, which could offer a new method for CO2-EOR and carbon storage.

19.
ACS Omega ; 8(28): 25134-25141, 2023 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-37483196

RESUMO

Catalysts are an important factor in reducing harsh reaction conditions and increasing oil yields for the cohydrogenation of coal-oil. In this article, nano-iron-based catalysts have been prepared by mechanical solid-phase ball milling with FeCl3·6H2O, Fe(NO3)3·9H2O, and ammonium carbonate as reactants. The catalysts were characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. With these catalysts, cohydrogenation behaviors of coal-oil have been carried out with Hami Baishihu coal and Karamay petrochemical coking residual oil under conditions of 400 °C, initial pressure of 7 MPa, and reaction time of 1 h. The results showed that the coal conversion rate reached 98.45% and the oil yield reached 77.73% when the catalyst prepared with FeCl3·6H2O as an iron source was added. Compared with research results reported in the literature, under the same conditions, the catalyst prepared in this article showed better catalytic activity in the cohydrogenation of coal-petrochemical coking residual oil.

20.
ACS Omega ; 8(21): 18400-18407, 2023 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-37273628

RESUMO

With the growing demand for gasoline and diesel fuel and the shortage of conventional oil reserves, there has been extensive interest in upgrading technologies for unconventional feedstocks such as heavy oil. Slurry bed reactors with high tolerance to heavy oil have been extensively investigated. Among them, dispersive MoS2 is favored for its excellent hydrogenation ability for heavy oil even under harsh reaction conditions such as high pressure and high temperature, its ability to effectively prevent damage to equipment from deposited coke, and its ability to meet the requirement of high catalyst dispersion for slurry bed reactors. This paper reviews the relationship between the structure and hydrogenation effectiveness of dispersive molybdenum disulfide, the hydrogenation mechanism, and the improvement of its hydrogenation performance by adding defects and compares the application of molybdenum disulfide in heavy oil hydrogenation, desulfurization, deoxygenation, and denitrification. It is found that the current research on dispersive molybdenum disulfide catalysts focuses mostly on the reduction of stacking layers and catalytic performance, and there is a lack of research on the lateral dimensions, microdomain regions, and defect sites of MoS2 catalysts. The relationship between catalyst structure and hydrogenation effect also lags far behind the application of MoS2 in the precipitation of hydrogen, etc. Oil-soluble and water-soluble MoS2 catalysts eventually need to be converted to a solid sulfide state to have hydrogenation activity. The conversion history of soluble catalysts to solid-type catalysts and the key to their improved catalytic effectiveness remain unclear.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA