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1.
Adv Mater ; 36(19): e2312548, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38323869

RESUMO

Solid electrolyte interface (SEI) is arguably the most important concern in graphite anodes, which determines their achievable Coulombic efficiency (CE) and cycling stability. In spent graphite anodes, there are already-formed (yet loose and/or broken) SEIs and some residual active lithium, which, if can be inherited in the regenerated electrodes, are highly desired to compensate for the lithium loss due to SEI formation. However, current graphite regenerated approaches easily destroy the thin SEIs and residue active lithium, making their reuse impossible. Herein, this work reports a fast-heating strategy (e.g., 1900 K for ≈150 ms) to upcycle degraded graphite via instantly converting the loose original SEI layer (≈100 nm thick) to a compact and mostly inorganic one (≈10-30 nm thick with a 26X higher Young's Modulus) and still retaining the activity of residual lithium. Thanks to the robust SEI and enclosed active lithium, the regenerated graphite exhibited 104.7% initial CE for half-cell and gifted the full cells with LiFePO4 significantly improved initial CE (98.8% versus 83.2%) and energy density (309.4 versus 281.4 Wh kg-1), as compared with commercial graphite. The as-proposed upcycling strategy turns the "waste" graphite into high-value prelithiated ones, along with significant economic and environmental benefits.

2.
Adv Mater ; 36(14): e2310756, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38174831

RESUMO

Using Li2S cathodes instead of S cathodes presents an opportunity to pair them with Li-free anodes (e.g., graphite), thereby circumventing anode-related issues, such as poor reversibility and safety, encountered in Li-S batteries. However, the moisture-sensitive nature of Li2S causes the release of hazardous H2S and the formation of insulative by-products, increasing the manufacturing difficulty and adversely affecting cathode performance. Here, Li4SnS4, a Li+ conductor that is air-stable according to the hard-soft acid-base principle, is formed in situ and uniformly on Li2S particles because Li2S itself participates in Li4SnS4 formation. When exposed to air (20% relative humidity), the protective Li4SnS4 layer maintains its components and structure, thus contributing to the enhanced stability of the Li2S@Li4SnS4 composite. In addition, the Li4SnS4 layer can accelerate the sluggish conversion of Li2S because of its favorable interfacial charge transfer, and continuously confine lithium polysulfides owing to its integrity during electrochemical processes. A graphite-Li2S pouch cell containing a Li2S@Li4SnS4 cathode is constructed, which shows stable cyclability with 97% capacity retention after 100 cycles. Hence, combining a desirable air-stable Li2S cathode and a highly reversible Li-free configuration offers potential practical applications of graphite-Li2S full cells.

3.
Nanomicro Lett ; 15(1): 234, 2023 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-37874412

RESUMO

Lithium (Li) metal electrodes show significantly different reversibility in the electrolytes with different salts. However, the understanding on how the salts impact on the Li loss remains unclear. Herein, using the electrolytes with different salts (e.g., lithium hexafluorophosphate (LiPF6), lithium difluoro(oxalato)borate (LiDFOB), and lithium bis(fluorosulfonyl)amide (LiFSI)) as examples, we decouple the irreversible Li loss (SEI Li+ and "dead" Li) during cycling. It is found that the accumulation of both SEI Li+ and "dead" Li may be responsible to the irreversible Li loss for the Li metal in the electrolyte with LiPF6 salt. While for the electrolytes with LiDFOB and LiFSI salts, the accumulation of "dead" Li predominates the Li loss. We also demonstrate that lithium nitrate and fluoroethylene carbonate additives could, respectively, function as the "dead" Li and SEI Li+ inhibitors. Inspired by the above understandings, we propose a universal procedure for the electrolyte design of Li metal batteries (LMBs): (i) decouple and find the main reason for the irreversible Li loss; (ii) add the corresponding electrolyte additive. With such a Li-loss-targeted strategy, the Li reversibility was significantly enhanced in the electrolytes with 1,2-dimethoxyethane, triethyl phosphate, and tetrahydrofuran solvents. Our strategy may broaden the scope of electrolyte design toward practical LMBs.

4.
Sci Rep ; 13(1): 17269, 2023 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-37828080

RESUMO

Toxoplasma gondii is an obligate parasitic protozoon that transmits to animals and humans via ingested food. Cats that act as T. gondii's final hosts play a critical role in T. gondii transmission by shedding millions of oocysts. Timely diagnosis of infected cats is essential for preventing toxoplasmosis because oocysts are a putative T. gondii source in epidemiology. We developed a new visual LAMP assay targeting the B1 gene to analyze single oocysts in cat feces in this study. The amplification result could be visually estimated based on the color change. LAMP assay analytical sensitivity was 101 copies/µL for the B1 gene plasmid, which was tenfold better than the PCR reaction. There were no cross-reactions with other parasites. The LAMP assay can detect a single T. gondii oocyst in 200 mg of cat feces. The LAMP assay detected a single oocyst in 200 mg cat feces at a higher rate than the PCR assay (83.3% vs. 50.0%).


Assuntos
Doenças do Gato , Toxoplasma , Animais , Humanos , Gatos , Toxoplasma/genética , Oocistos/genética , Técnicas de Amplificação de Ácido Nucleico , Fezes/parasitologia , Doenças do Gato/diagnóstico , DNA de Protozoário/genética
5.
Materials (Basel) ; 16(13)2023 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-37445128

RESUMO

In order to increase the content of mineral admixtures in cement, this study proposes a method for preparing a high-volume mineral admixture cementitious material (HMAC) using superfine cement as a reverse filling material. Firstly, superfine cement is prepared through mechanical grinding. Then, the activity of mineral admixtures (such as slag and fly ash) is enhanced by mechanical grinding, sulfate activation, and alkali activation methods. Meanwhile, the evolution of HMCM from microstructure to macroscopic mechanical behavior is studied by combining a laser particle size analyzer and a scanning electron microscope. Furthermore, the reverse filling mechanism of superfine cement on mineral admixtures under different activation conditions is proposed. Results show that superfine cement can largely improve the utilization rate of cement clinker and the compressive strength of cementitious materials. In the condition that the compressive strength is not lower than that of the control group (without mineral admixture), the content of mineral admixture can be increased to 50%, 70%, and 90% after mechanical grinding, sulfate activation, and alkali activation, respectively. Analysis indicates that the reverse filling effect of superfine cement is the main reason for improving the density of the HMCM.

6.
Parasit Vectors ; 16(1): 256, 2023 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-37518013

RESUMO

BACKGROUND: Toxoplasma gondii is an opportunistic protozoan that is ubiquitous in humans and animals. It can invade any human organ and cause severe diseases, including toxoplasma ophthalmopathy, meningoencephalitis, and liver necrosis. Porcine toxoplasmosis is prevalent in China. CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) and Cas (CRISPR-Associated Protein) systems are widely used for gene editing and pathogen detection. CRISPR-based diagnostics are molecular assays that have been developed to detect parasites with high sensitivity and specificity. METHODS: This study aimed to establish a combined CRISPR/Cas12a and RPA rapid detection method for T. gondii by targeting the B1 gene and 529 bp repeat element (529 RE). The detection results could be visualized by the fluorescence or lateral flow strips (LFS). The sensitivity and specificity of the method were evaluated, and T. gondii-infected mouse blood was used for detection. RESULTS: The results indicated that the established method for T. gondii detection was satisfactory, with a detection limit of 1.5 cp/µl for the two loci. Moreover, the B1 gene could detect 1 tachyzoite per reaction, and the 529 RE could detect 0.1 tachyzoite per reaction, consistently with the highly sensitive nested polymerase chain reaction (PCR) results. The method was suitable for strains, including RH, and did not cross-react with other protozoa DNA with similar habits. The T. gondii-infected mouse blood samples were all positive for T. gondii at 1, 3, and 5 days post infection (dpi). CONCLUSIONS: This study established a rapid, sensitive, and time-saving DNA detection method for T. gondii that has the potential to be an alternative tool for T. gondii detection in the field.


Assuntos
Toxoplasma , Toxoplasmose , Animais , Humanos , Camundongos , Suínos , Sistemas CRISPR-Cas , Toxoplasmose/parasitologia , Toxoplasma/genética , Reação em Cadeia da Polimerase , Sensibilidade e Especificidade , DNA de Protozoário/análise
7.
Materials (Basel) ; 16(10)2023 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-37241355

RESUMO

S2--enriched alkali-activator (SEAA) was prepared by modifying the alkali activator through Na2S. The effects of S2--enriched alkali-activated slag (SEAAS) on the solidification performance of Pb and Cd in MSWI fly ash were investigated using SEAAS as the solidification material for MSWI fly ash. Combined with microscopic analysis through scanning electron microscopy (SEM), X-ray fluorescence spectroscopy (XRF), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR), the effects of SEAAS on the micro-morphology and molecular composition of MSWI fly ash were studied. The solidification mechanism of Pb and Cd in S2--enriched alkali-activated MSWI fly ash was discussed in detail. The results showed that the solidification performance for Pb and Cd in MSWI fly ash induced by SEAAS was significantly enhanced first and then improved gradually with the increase in dosage of ground granulated blast-furnace slag (GGBS). Under a low GGBS dosage of 25%, SEAAS could eliminate the problem of severely exceeding permitted Pb and Cd in MSWI fly ash, which compensated for the deficiency of alkali-activated slag (AAS) in terms of solidifying Cd in MSWI fly ash. The highly alkaline environment provided by SEAA promoted the massive dissolution of S2- in the solvent, which endowed the SEAAS with a stronger ability to capture Cd. Pb and Cd in MSWI fly ash were efficiently solidified by SEAAS under the synergistic effects of sulfide precipitation and chemical bonding of polymerization products.

8.
Materials (Basel) ; 16(7)2023 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-37049001

RESUMO

In this investigation, non-spontaneous combustion coal gangue was activated by two methods: (1) low-temperature calcination and (2) calcium addition. Differences in the activity of the activated coal gangue were studied at various calcination temperatures and amounts of calcium addition. Meanwhile, the cementation activity of the activated coal gangue was evaluated according to the activity effect analysis. Furthermore, the influences of the activated coal gangue on the cementation activity of cement were investigated. The results indicated that the activities of the activated coal gangue increased at a temperature between 500 °C and 700 °C. The calcium addition method can also increase the activity of coal gangue, with the effect being better when the gangue is mixed with slag. The addition of calcium and the calcination of coal gangue can promote the production of active minerals such as metakaolin, which is the main reason for the increased cementation activity.

9.
ACS Appl Mater Interfaces ; 15(15): 18763-18770, 2023 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-37036946

RESUMO

In conventional lithium-ion batteries (LIBs), active lithium (Li) ions, which function as charge carriers and could only be supplied by the Li-containing cathodes, are also consumed during the formation of the solid electrolyte interphase. Such irreversible Li loss reduces the energy density of LIBs and is highly desired to be compensated by prelithiation additives. Herein, lithium selenide (Li2Se), which could be irreversibly converted into selenide (Se) at 2.5-3.8 V and thus supplies additional Li, is proposed as a cathode prelithiation additive for LIBs. Compared with previously reported prelithiation reagents (e.g., Li6CoO4, Li2O, and Li2S), the delithiation of Li2Se not only delivers a high specific capacity but also avoids gas release and incompatibility with carbonate electrolytes. The electrochemical characterizations show that with the addition of 6 wt % Li2Se to the LiFePO4 (LFP) cathodes, a 9% increase in the initial specific capacity in half Li||LFP cells and a 19.8% increase in the energy density (based on the total mass of the two electrodes' materials) could be achieved without sacrificing the other battery performance. This work demonstrates the possibility to use Li2Se as a high-efficiency prelithiation additive for LIBs and provides a solution to the high-energy LIBs.

10.
Spectrochim Acta A Mol Biomol Spectrosc ; 293: 122421, 2023 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-36801729

RESUMO

It is well known that the physicochemical properties of nanocarriers, which are closely related to the surface modification of nanoparticles, have crucial impacts on their biological effects. Herein, the interaction between functionalized degradable dendritic mesoporous silica nanoparticles (DDMSNs) and bovine serum albumin (BSA) was investigated for probing into the nanocarriers' potential toxicity using multi-spectroscopy such as ultraviolet/visible (UV/Vis), synchronous fluorescence, Raman and circular dichroism (CD) spectroscopy. BSA, owing to its structural homology and high sequence similarity with HSA, was employed as the model protein to study the interactions with DDMSNs, amino-modified DDMSNs (DDMSNs-NH2) and hyaluronic acid (HA) coated nanoparticles (DDMSNs-NH2-HA). It was found that the static quenching behavior of DDMSNs-NH2-HA to BSA was accompanied by an endothermic and hydrophobic force-driven thermodynamic process, which was confirmed by fluorescence quenching spectroscopic studies and thermodynamic analysis. Furthermore, the conformational variations of BSA upon interaction with nanocarriers were observed by combination of UV/Vis, synchronous fluorescence, Raman and CD spectroscopy. The microstructure of amino residues in BSA changed due to the existence of nanoparticles, for example, the amino residues and hydrophobic groups exposed to microenvironment and the alpha helix (α-helix) content of BSA decreased. Specially, through thermodynamic analysis, the diverse binding modes and driving forces between nanoparticles and BSA were discovered because of different surface modifications on DDMSNs, DDMSNs-NH2 and DDMSNs-NH2-HA. We believe that this work can promote the interpretation of mutual impact between nanoparticles and biomolecules, which will be in favor of predicting the biological toxicity of nano-DDS and engineering functionalized nanocarriers.


Assuntos
Nanopartículas , Soroalbumina Bovina , Soroalbumina Bovina/química , Dicroísmo Circular , Espectrometria de Fluorescência/métodos , Termodinâmica , Ligação Proteica , Sítios de Ligação , Espectrofotometria Ultravioleta/métodos
12.
Angew Chem Int Ed Engl ; 62(9): e202218803, 2023 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-36596979

RESUMO

The use of non-solvating, or as-called sparingly-solvating, electrolytes (NSEs), is regarded as one of the most promising solutions to the obstacles to the practical applications of Li-S batteries. However, it remains a puzzle that long-life Li-S batteries have rarely, if not never, been reported with NSEs, despite their good compatibility with Li anode. Here, we find the capacity decay of Li-S batteries in NSEs is mainly due to the accumulation of the dead Li2 S at the cathode side, rather than the degradation of the anodes or electrolytes. Based on this understanding, we propose an electrochemical strategy to reactivate the accumulated Li2 S and revive the dead Li-S batteries in NSEs. With such a facile approach, Li-S batteries with significantly improved cycling stability and accelerated dynamics are achieved with diglyme-, acetonitrile- and 1,2-dimethoxyethane-based NSEs. Our finding may rebuild the confidence in exploiting non-solvating Li-S batteries with practical competitiveness.

13.
Nanomaterials (Basel) ; 12(22)2022 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-36432333

RESUMO

This study focuses on overcoming the agglomeration issue of nano-SiO2 powder in cement, facilitating the strengthening mechanism of cement-based materials. A nano-SiO2 precursor solution (NSPS) was added to cement-based materials to replace nano-SiO2 powder. The influencing laws of the alkalinity and dosage of the NSPS on the mechanical properties of cement were investigated. Further, the strengthening mechanism of the mechanical properties of cement-based materials after internal nano-SiO2 production was analysed. The results show that (1) when the alkalinity of the precursor solution is a weak acid (pH = 6), the compressive strength of cement-based materials after internal nano-SiO2 production is 25%~36% higher than that of pure cement-based materials and 16%~22% higher than that of cement-based materials with silica fume; (2) when the solid content of SiO2 in the current displacement solution is about 0.16% of the cement mass, the compressive strength of the prepared cement-based material is the highest. With the continuous increase in the solid content of SiO2 in the precursor solution, the compressive strength of cement-based materials after internal nano-SiO2 production decreases but is always greater than the compressive strength of the cement-based material mixed with nano-SiO2 micro powder. According to a microstructural analysis, nano-SiO2 particles that precipitate from the precursor solution can facilitate the hydration process of cement and enrich the gel products formed on the cement particle surface. In addition, new network structures among cement particles are formed, and precipitated nano-SiO2 particles fill in the spaces among these cement particles as crystal nuclei to connect the cement particles more tightly and compact the cement-based materials. This reinforces the mechanical properties of cement-based materials.

14.
Materials (Basel) ; 15(20)2022 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-36295275

RESUMO

The issues associated with the fabrication of nano-silica (NS) mineral powder, such as high cost and agglomeration, can be effectively mitigated by using a precursor solution of NS as the external mixture of cement-based materials. Based on the liquid-phase preparation of NS mineral powder, its preparation technology was thoroughly investigated herein. The precursor solution of NS was synthesized using acid media (HCL, HNO3, HBO3, HCOOH, CH3COOH)-the acetic acid concentration was 1~15%-and siliceous materials. (The concentration of sodium silicate was 20~38%). In addition, the pH value (pH4~pH8) of the precursor solution was measured using a pH detector. The indexes of NS, such as precipitation time, morphology, and distribution, were observed to formulate a preparation technique for the precursor solution of NS that possessed the best results for the precipitation of nanoparticles. From the acquired results, it was demonstrated that acetic acid solution (concentration ≤ 3%) and sodium silicate solution (concentration ≤ 25%) were mixed into a solution with pH = 6, which was the optimum mixing ratio for the precursor solution of NS. The prepared precursor solution of NS was also added to the Ca(OH)2 saturated solution, and the precursor solution became active from a stable state. Then, NS particles were precipitated in an alkaline solution and reacted with Ca(OH)2 to form calcium silicate gel, which made the solution increasingly turbid and generated many visible and uniformed flocculating substances. With time, gels were continuously produced, which then turn white. Similarly, NS particles can be precipitated when the precursor solution is added to cement paste, which reacts with the Ca(OH)2 to generate CSH gel and improve the compactness of the cement paste.

15.
PLoS One ; 17(4): e0267017, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35421166

RESUMO

Drug resistance, either intrinsic or acquired, can impair treatment effects and result in increased cell motility and death. MicroRNA-21 (miR-21), a proto-oncogene, may facilitate the development or maintenance of drug resistance in cancer cells. Restoring drug sensitivity can improve therapeutic strategies, a possibility that requires functional evaluation and mechanistic exploration. For miR-21 detection, matched tissue samples from 30 head and neck squamous cell carcinoma (HNSCC) patients and 8 head and neck cancer (HNC) cell lines were obtained. Reverse transcription-PCR to detect expression, MTT and clonogenic assays to evaluate cell proliferation, apoptosis assays, resazurin cell viability assays, western blot and luciferase reporter assays to detect protein expression, and flow cytometry to analyse the cell cycle were adopted. Compared to the corresponding normal control (NC) tissues, 25 cancer tissues had miR-21 upregulation among the 30 matched pair tissues (25/30, 83.8%); furthermore, among the 8 HNC cell lines, miR-21 expression that was notably upregulated in three: UPCI-4B, UMSCC-1, and UPCI-15B. In both the UMSCC-1 and UPCI-4B cell lines, the miR-21 mimic enhanced cell proliferation with reduced apoptosis and increased viability, whereas the miR-21 inhibitor resulted in the opposite effects (all P<0.001); additionally, miR-21 directly targeted the tumour suppressor phosphatase and tensin homologue (PTEN) and inhibited PTEN expression. Furthermore, the miR-21 mimic induced cisplatin resistance, while the miR-21 inhibitor restored cisplatin sensitivity. Overexpression of miR-21 can enhance cell proliferation, reduce apoptosis, and induce drug resistance by inhibiting PTEN expression. Targeting miR-21 may facilitate cancer diagnosis, restore drug sensitivity, and improve therapeutic effects.


Assuntos
Neoplasias de Cabeça e Pescoço , MicroRNAs , Apoptose/genética , Linhagem Celular Tumoral , Proliferação de Células , Cisplatino/farmacologia , Regulação Neoplásica da Expressão Gênica , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Neoplasias de Cabeça e Pescoço/genética , Humanos , MicroRNAs/metabolismo , Carcinoma de Células Escamosas de Cabeça e Pescoço/tratamento farmacológico , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética
17.
Biomed Pharmacother ; 144: 112281, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34624676

RESUMO

Schistosomiasis is a serious parasitic infection caused by Schistosoma. The parasite deposits eggs in the host liver, causing inflammation that activates hepatic stellate cells (HSCs), which leads to liver fibrosis. Currently, there is no effective therapy for liver fibrosis; thus, treatments are urgently needed. Therefore, in the present study, mice infected with Schistosoma japonicum were treated with JQ-1, a small-molecule bromodomain inhibitor with reliable anti-tumor and anti-inflammatory activities. The fibrotic area of the liver measured by computer-assisted morphometric analysis and the expression levels of the cytoskeletal protein alpha smooth muscle actin (α-SMA) and of collagen assessed by quantitative PCR, Western blot and immunohistochemistry were significantly decreased in the liver following JQ-1 treatment compared with vehicle-treated controls. Total RNA was extracted from the liver of JQ-1-treated Schistosoma-infected mice for RNA-sequencing analysis. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses indicated that JQ-1 affected biological processes and the expression of cellular components known to play key roles in the transdifferentiation of HSCs to myofibroblasts. In vitro treatment with JQ-1 of JS-1 cells, a mouse HSC line, indicated that JQ-1 significantly inhibited JS-1 proliferation but had no effect on JS-1 activity, senescence, or apoptosis. Western blot results showed that JQ-1 inhibited the expression levels of phosphorylated JAK2 and phosphorylated STAT3 without altering expression levels of these non-phosphorylated proteins. Taken together, these findings suggested that JQ-1 treatment ameliorated S. japonicum egg-induced liver fibrosis, at least in part, by suppressing HSC activation and proliferation through the inhibition of JAK2/STAT3 signaling. These results lay a foundation for the development of novel approaches to treat and control liver fibrosis caused by S. japonicum.


Assuntos
Antifibróticos/farmacologia , Azepinas/farmacologia , Células Estreladas do Fígado/efeitos dos fármacos , Janus Quinase 2/metabolismo , Cirrose Hepática/prevenção & controle , Fígado/efeitos dos fármacos , Fator de Transcrição STAT3/metabolismo , Schistosoma japonicum/patogenicidade , Esquistossomose/tratamento farmacológico , Triazóis/farmacologia , Animais , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Modelos Animais de Doenças , Feminino , Células Estreladas do Fígado/enzimologia , Células Estreladas do Fígado/parasitologia , Células Estreladas do Fígado/patologia , Interações Hospedeiro-Patógeno , Fígado/enzimologia , Fígado/parasitologia , Fígado/patologia , Cirrose Hepática/enzimologia , Cirrose Hepática/parasitologia , Cirrose Hepática/patologia , Camundongos Endogâmicos C57BL , Fosforilação , Esquistossomose/enzimologia , Esquistossomose/parasitologia , Esquistossomose/patologia , Transdução de Sinais
18.
ACS Omega ; 6(20): 13508-13515, 2021 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-34056497

RESUMO

It is significantly crucial to develop a robust pretreatment for the quantitative analysis of herbs. However, the traditional strategies are time-consuming, tedious, and not eco-friendly. In this work, cloud point extraction (CPE) is engineered for the simultaneous separation and enrichment of ferulic acid (FA), chlorogenic acid (CLA), and caffeic acid (CA) from dandelion prior to its determination by high-performance liquid chromatography (HPLC). A famous nonionic surfactant of Triton X-114 was selected as an extractant of CPE, and parameters affecting the extraction, such as surfactant concentration, salt content, pH value, temperature, and incubation time, were investigated carefully. Furthermore, the well-designed CPE with ultrasonic assistance combined with HPLC was developed for the detection of the target analytes in dandelion. The established method having a good linearity in the range of 0.15-26.2 mg L-1 with R 2 more than 0.9979 and the spiked recoveries ranging from 81 to 96% was applied to test real samples of dandelion. The contents of CA in samples were consistent with those assayed by the method (Chinese Pharmacopoeia 2015). The proposed method afforded good analytical performances, shorter pretreatment time (65 min), and less organic solvent consumption (less than 1.0 mL). It was proved that the developed method presented a facile, inexpensive, efficient, and environment-friendly pretreatment and can be used for the quantitative analysis of CLA, CA, and FA in dandelion. As expected, the proposed method would be a promising potential for the quality analysis of herbal medicines.

19.
Materials (Basel) ; 14(8)2021 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-33921393

RESUMO

Setting time and mechanical properties are key metrics needed to assess the properties of municipal solid waste incineration (MSWI) bottom ash alkali-activated samples. This study investigated the solidification law, polymerization, and strength development mechanism in response to NaOH and liquid sodium silicate addition. Scanning electron microscopy and X-ray diffraction were used to identify the formation rules of polymerization products and the mechanism of the underlying polymerization reaction under different excitation conditions. The results identify a strongly alkaline environment as the key factor for the dissolution of active substances as well as for the formation of polymerization products. The self-condensation reaction of liquid sodium silicate in the supersaturated state (caused by the loss of free water) is the major reason for the rapid coagulation of alkali-activated samples. The combination of both NaOH and liquid sodium silicate achieves the optimal effect, because they play a compatible coupling role.

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