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1.
Mycopathologia ; 189(2): 20, 2024 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-38407662

RESUMEN

Candidal granuloma is an uncommon type of deep chronic cutaneous candidiasis. Candida albican is the most common causative pathogen for candidal granuloma. We report herein the original case of a 69-year-old Chinese woman presented with a 3-year of painful cutaneous lesion on the back of left hand. Physical examination revealed a 4 × 5 cm large infiltrative reddish plaque with unclear boundaries. The yellow-white crusts were observed on the uneven surface of plaque. Histopathological examination of biopsy tissue revealed that yeast cells and the horizontal section of hyphae in the dermis by hematoxylin eosin staining and periodic acid-Schiff staining. Finally, the pathogen was identified as Candida parapsilosis by mycological examination and molecular identification. The patient was treated with itraconazole oral 200 mg twice daily combined with topical terbinafine hydrochloride cream for 2 months. The lesions were fully resolved and no recurrence was observed. Since the cutaneous infection caused by C. parasilosis were rarely reported, we also reviewed all 11 cases of cutaneous infection caused by C. parapsilosis in the PubMed. Our study highlighted that chronic unilateral infiltrated plaques or ulcers should be aware of the occurrence of fungal granuloma including candidal granuloma especially in immunocompromised patients.


Asunto(s)
Candidiasis Mucocutánea Crónica , Candidiasis , Femenino , Humanos , Anciano , Candida parapsilosis , Granuloma/diagnóstico , Granuloma/tratamiento farmacológico , Celulitis (Flemón) , Candida , Candidiasis/diagnóstico , Candidiasis/tratamiento farmacológico
2.
J Am Acad Dermatol ; 89(5): 911-919, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37019385

RESUMEN

BACKGROUND: Alopecia areata (AA) is a CD8+ T cell-mediated autoimmune disease characterized by nonscarring hair loss. Ivarmacitinib, which is a selective oral Janus kinase 1 inhibitor, may interrupt certain cytokine signaling implicated in the pathogenesis of AA. OBJECTIVE: To evaluate the efficacy and safety of ivarmacitinib in adult patients with AA who have ≥25% scalp hair loss. METHODS: Eligible patients were randomized 1:1:1:1 to receive ivarmacitinib 2, 4, or 8 mg once daily or placebo for 24 weeks. The primary end point was the percentage change from baseline in the Severity of Alopecia Tool score at week 24. RESULTS: A total of 94 patients were randomized. At week 24, the least squares mean difference in the percentage change from baseline in the Severity of Alopecia Tool score for ivarmacitinib 2, 4, and 8 mg and placebo groups were -30.51% (90% CI, -45.25, -15.76), -56.11% (90% CI, -70.28, -41.95), -51.01% (90% CI, -65.20, -36.82), and -19.87% (90% CI, -33.99, -5.75), respectively. Two serious adverse events-follicular lymphoma and COVID-19 pneumonia-were reported. LIMITATIONS: A small sample size limits the generalizability of the results. CONCLUSION: Treatment with ivarmacitinib 4 and 8 mg doses in patients with moderate and severe AA for 24 weeks was efficacious and generally tolerated.


Asunto(s)
Alopecia Areata , COVID-19 , Inhibidores de las Cinasas Janus , Humanos , Adulto , Alopecia Areata/tratamiento farmacológico , Inhibidores de las Cinasas Janus/efectos adversos
3.
Dermatology ; 237(4): 603-610, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33352561

RESUMEN

BACKGROUND: Topical agents are still the mainstay for the treatment of mild-to-moderate plaque psoriasis, in which fixed combinations play an important role. Tazarotene/betamethasone dipropionate (Taz/BD) cream is a novel fixed combination approved for treating plaque psoriasis in China, but its efficacy and safety have not been verified in a real-world environment. OBJECTIVES: The primary objective was to investigate the efficacy and safety of Taz/BD cream in treating plaque psoriasis. The secondary objectives were to assess its relapse after discontinuation and the efficacy and safety profiles during retreatment. METHODS: A prospective, multicenter, large-scale observational study was conducted. Adult patients with chronic plaque psoriasis involving <20% of the body surface area were enrolled. Taz/BD cream was applied once daily for 4 weeks. Patients who achieved ≥90% improvement in the Psoriasis Area and Severity Index (PASI) from baseline to week 4 were followed up to investigate relapse after drug withdrawal. Relapsed patients underwent another 4-week treatment. RESULTS: In total, 2,299 eligible patients were enrolled, and 2,095 patients (91.1%) completed the 4-week study. The mean PASI improvement at week 4 was 53.7%, and the PASI 50/75 response rates were 62.5 and 26.8%, respectively. The mean PASI reduction in plaque induration, desquamation and erythema were 58.3, 61.0 and 40.0%, respectively (p < 0.001). Adverse reactions occurred in 445 patients (20.8%) at week 4. The most frequently reported adverse reactions were local skin irritation, including pruritus (10%), pain (6.7%), erythema (6.1%) and desquamation (1.8%). During the post-treatment period, 47 patients (24.0%) relapsed within 8 weeks after drug discontinuation. Forty-five patients were retreated for another 4 weeks, and the PASI 50/75 response rates were 72.7 and 40.9%, respectively. There were no unexpected safety signals during retreatment. CONCLUSION: Taz/BD cream is effective and well tolerated in treating mild-to-moderate plaque psoriasis under near real-world conditions and demonstrates efficacy and safety during retreatment.


Asunto(s)
Antiinflamatorios/uso terapéutico , Betametasona/análogos & derivados , Fármacos Dermatológicos/uso terapéutico , Ácidos Nicotínicos/uso terapéutico , Psoriasis/tratamiento farmacológico , Administración Cutánea , Adulto , Antiinflamatorios/administración & dosificación , Betametasona/efectos adversos , Betametasona/uso terapéutico , Fármacos Dermatológicos/administración & dosificación , Combinación de Medicamentos , Eritema/inducido químicamente , Femenino , Humanos , Masculino , Persona de Mediana Edad , Ácidos Nicotínicos/efectos adversos , Dolor/inducido químicamente , Estudios Prospectivos , Prurito/inducido químicamente , Recurrencia , Retratamiento/efectos adversos , Índice de Severidad de la Enfermedad , Crema para la Piel
4.
J Sep Sci ; 44(19): 3608-3617, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34329505

RESUMEN

Advancement of novel coating materials for solid-phase microextraction is highly needed for sample pretreatment. Herein, a triazine-based covalent organic polymer was constructed from the monomers of cyanuric chloride and trans-stilbene via the Friedel-Crafts reaction and thereafter used as a solid-phase microextraction fiber coating for the extraction of polycyclic aromatic hydrocarbons and their nitrated and oxygenated derivatives. The newly-developed solid-phase microextraction method coupled with gas chromatography/flame ionization detection gives enhancement factors of 548-1236 and limits of detection of 0.40-2.81 ng/L for the determination of polycyclic aromatic hydrocarbons and their derivatives. The one fiber precision for five replicate determinations of the analytes and the fiber-to-fiber precision with three parallel prepared fibers, expressed as relative standard deviations, was in the range of 4.6-9.4% and 6.2-10.9%, respectively. The relative recoveries of the analytes for environmental water samples were in the range of 88.6-106.4% with the relative standard deviations ranging from 4.0 to 11.7% (n = 5).

5.
Mikrochim Acta ; 186(3): 145, 2019 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-30707320

RESUMEN

A new covalent organic framework (COF) was synthesized by the amide coupling between 1,3,5-tris(4-aminophenyl)benzene and trimesoyl chloride at room temperature. The COF was applied as a steel fiber coating for the solid phase microextraction of polycyclic aromatic hydrocarbons (PAHs) from water samples. The effect of extraction time, salt concentration, and extraction temperature on the efficiency of SPME was optimized by a Box-Behnken design. The PAHs were quantified by gas chromatography with mass spectrometric detection. Figures of merit include (a) a wide linear range (typically from 0.2 ng L-1 to 2 µg L-1), (b) low limits of detection (0.29 to 0.94 ng L-1 at S/N = 3), and (c) high enrichment factors (EFs; 819-2420). Density functional theory was employed to study the interaction between the COF cluster and the PAHs. The results demonstrated that the EFs increase with the enhancement of π stacking interaction. The repeatability (one fiber; n = 5) and reproducibility (fiber to fiber; n = 5), expressed as the relative standard deviations were in the range of 4.3%-8.4% and 8.5-11.0%, respectively. The recoveries of the PAHs from water samples spiked at levels of 20.0 and 100 ng L-1 ranged from 79.0% to 105.0%. Graphical abstract A covalent organic framework prepared from 1,3,5-tris(4-aminophenyl)benzene and trimesoyl chloride (TAPB-TMC-COF) was synthesized and employed as solid phase microextraction (SPME) fiber coating for the extraction of polycyclic aromatic hydrocarbons from water samples prior to gas chromatography (GC) - mass spectrometric (MS) detection.

6.
Mikrochim Acta ; 185(12): 554, 2018 11 20.
Artículo en Inglés | MEDLINE | ID: mdl-30460410

RESUMEN

Magnetic knitting aromatic polymers (Fe3O4/KAPs) are introduced here as a new kind of sorbents. KAPs are hyper-cross-linked-polymers that were prepared via a Friedl-Crafts reaction from triphenylphosphine and benzene as building blocks. The Fe3O4/KAP composite was obtained by coprecipitation of KAP with magnetite nanoparticles. The resulting Fe3O4/KAP is shown to be a viable magnetic sorbent for various organic materials such as the phenylurea herbicides (PUHs), including metoxuron, monuron, chlortoluron, monolinuron and buturon, and also for various phthalates, polycyclic aromatic hydrocarbons and chlorophenols. The Fe3O4/KAP was characterized by means of Brunauer-Emmett-Teller surface area measurements, Fourier-transform infrared spectroscopy, thermogravimetry, X-ray diffraction, scanning electron microscopy and transmission electron microscopy. Following desorption with acetonitrile, the analytes were quantified by using HPLC with UV detection. The effects of adsorbent dosage, extraction time, sample pH, ionic strength, desorption solvent and desorption time were optimized for the PUHs. Under optimal conditions, response is linear from 0.5-1.0 up to 50 ng·mL-1 for the five PUHs. Lower limits of detection range between 0.05 and 0.30 ng·mL-1. Other figures of merit include (a) high enrichment factors (60-297), (b) good recoveries (91.8-106.5%), and (c) relative standard deviations of <8.4%. The method was successfully applied to analysis of the PUHs in real samples (bottled mixed juice, milk and soymilk). The results indicate that such Fe3O4/KAPs have a wide application scope as an adsorbent for use in magnetic solid phase extraction. Graphical abstract A magnetic knitting aromatic polymer based nanocomposite (Fe3O4/KAP) was prepared by a one-pot method and explored as an absorbent for magnetic solid-phase extraction (MSPE) of phenylurea herbicides (PUHs) from bottled mixed juice, milk and soymilk samples before quantitation by HPLC with UV detection.

8.
J Sep Sci ; 40(10): 2207-2213, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28371316

RESUMEN

Magnetic spherical carbon was synthesized by a facile hydrothermal carbonization procedure with biomass glucose as the carbon precursor and nanoclusters iron colloid as magnetic precursor. The textures of the as-prepared magnetic spherical carbon were characterized by nitrogen adsorption-desorption isotherms, X-ray diffraction, transmission electron microscopy, scanning electron microscopy and vibration sample magnetometry. Results indicated that the magnetic spherical carbon possessed high surface area as well as strong magnetism, which endows the material with good adsorption capability and easy separation properties. To assess its absorption performance, the magnetic spherical carbon was employed as adsorbent for the extraction and preconcentration of phthalate esters from lake water and milk samples before high-performance liquid chromatographic analysis. Some key parameters that could influence the enrichment efficiency were investigated. Under the optimum conditions, a good linearity was achieved with the linear correlation coefficients higher than 0.9973. The limits of detection (S/N = 3) were 0.05-0.08 ng/mL for lake water and 0.1-0.2 ng/mL for milk samples. The recoveries of the analytes for the method were in the range 80.1-112.6%.


Asunto(s)
Carbono , Ésteres/aislamiento & purificación , Lagos/química , Leche/química , Ácidos Ftálicos/aislamiento & purificación , Adsorción , Animales , Cromatografía Líquida de Alta Presión
9.
J Sep Sci ; 40(8): 1637-1643, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28195426

RESUMEN

A new kind of magnetic N-doped mesoporous carbon was prepared by the one-step carbonization of a hybrid precursor (glucose, melamine, and iron chloride) in a N2 atmosphere with a eutectic salt (KCl/ZnCl2 ) as the porogen. The obtained magnetic N-doped mesoporous carbon showed excellent characteristics, such as strong magnetic response, high surface area, large pore volume, and abundant π-electron system, which endow it with a great potential as a magnetic solid-phase extraction adsorbent. To evaluate its adsorption performance, the magnetic N-doped mesoporous carbon was used for the extraction of three phthalate esters from soft drink samples followed by high-performance liquid chromatographic analysis. Under the optimum conditions, the developed method showed a good linearity (1.0-120.0 ng/mL), low limit of detection (0.1-0.3 ng/mL, S/N = 3), and good recoveries (83.2-119.0%) in soft drink samples. The results indicated that the magnetic N-doped mesoporous carbon has an excellent adsorption capacity for phthalate esters and the present method is simple, accurate, and highly efficient for the extraction and determination of phthalate esters in complex matrix samples.


Asunto(s)
Bebidas Gaseosas/análisis , Ésteres/aislamiento & purificación , Ácidos Ftálicos/aislamiento & purificación , Adsorción , Carbono , Magnetismo , Extracción en Fase Sólida
10.
Mycoses ; 60(6): 394-401, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28239908

RESUMEN

To study the pathogenicity of Conidiobolus coronatus (C. coronatus) and Fusarium solani (F. solani) in animal models. Immunocompromised mice were treated with cyclophosphamide and prednisolone via intraperitoneal injection before and after inoculation. According to pathogenic characteristics of different fungi, C. coronatus was used to infect mice via intravenous inoculation, intraperitoneal inoculation, gastrointestinal infusion and intradermal inoculation methods. And F. solani was used to infect mice by inoculation via the abraded or normal skin. In the group of immunocompromised mice, C. coronatus was isolated from the lung tissues of one mouse on day 7 and another on day 10 respectively. The corresponding histopathology revealed infiltration of local inflammatory cells in the lung tissue. Pathogenic lesions were observed in all normal and immunocompromised mice infected with F. solani via abraded skin. The lesions in the immunocompromised mice were more severe and persisted longer than those in the normal mice. Moreover, hyphae were mostly observed in the histopathological examination and fungal culture from the immunocompromised mouse. The pathogenicity of C. coronatus was relatively weak as it did not induce local infections and did not disseminate the disease in immunocompetent and immunocompromised mice. Therefore, F. solani is a type of opportunistic pathogenic fungus, and abraded skin is one of the causative routes of infection.


Asunto(s)
Conidiobolus/patogenicidad , Fusariosis/patología , Fusarium/patogenicidad , Cigomicosis/patología , Animales , Conidiobolus/efectos de los fármacos , Ciclofosfamida/farmacología , Modelos Animales de Enfermedad , Fusariosis/tratamiento farmacológico , Fusarium/efectos de los fármacos , Huésped Inmunocomprometido , Inmunosupresores/farmacología , Pulmón/microbiología , Pulmón/patología , Masculino , Ratones , Ratones Endogámicos ICR , Prednisolona/farmacología , Piel/microbiología , Piel/patología , Cigomicosis/tratamiento farmacológico
11.
Postepy Dermatol Alergol ; 38(2): 338-339, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-34408601
13.
Food Chem ; 439: 138182, 2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38100880

RESUMEN

Analysis of organochlorine pesticides (OCPs) residues in milk faces a significant challenge. Herein, a sea urchin structured covalent organic framework bearing boric acid groups named COF-B(OH)2 was synthesized and applied as a coating material for solid-phase microextraction (SPME) of the OCPs in cattle's milk. Its performance was superior to that of three commonly used commercial SPME fibers, which could be due to the coexistence of hydrogen bonding, halogen bonding, π-stacking and electrostatic interactions. Besides, the fiber coating displayed good stability and reusability. After optimization, a COF-B(OH)2 based SPME coupled with gas chromatography-electron capture detection was established for the sensitive detection of the OCPs from milk samples. The limits of detection (S/N = 3) were between 0.04 and 1.00 µg kg-1. Satisfactory accuracy was achieved with the method recoveries in the range of 87.5 % to 112.5 %. These results manifest the feasibility of the COF-B(OH)2 coated fiber for the enrichment of the trace OCPs from milk samples.


Asunto(s)
Hidrocarburos Clorados , Estructuras Metalorgánicas , Residuos de Plaguicidas , Plaguicidas , Contaminantes Químicos del Agua , Animales , Bovinos , Estructuras Metalorgánicas/análisis , Adsorción , Leche/química , Contaminantes Químicos del Agua/análisis , Reproducibilidad de los Resultados , Plaguicidas/análisis , Hidrocarburos Clorados/análisis , Residuos de Plaguicidas/análisis , Microextracción en Fase Sólida/métodos
14.
J Hazard Mater ; 465: 133293, 2024 03 05.
Artículo en Inglés | MEDLINE | ID: mdl-38141301

RESUMEN

Autochthonous bioaugmentation and nutrient biostimulation are promising bioremediation methods for polycyclic aromatic hydrocarbons (PAHs) in contaminated agricultural soils, but little is known about their combined working mechanism. In this study, a microcosm trial was conducted to explore the combined mechanism of autochthonous fungal bioaugmentation and ammonium nitrogen biostimulation, using DNA stable-isotope-probing (DNA-SIP) and microbial network analysis. Both treatments significantly improved phenanthrene (PHE) removal, with their combined application producing the best results. The microbial community composition was notably altered by all bioremediation treatments, particularly the PHE-degrading bacterial and fungal taxa. Fungal bioaugmentation removed PAHs through extracellular enzyme secretion but reduced soil microbial diversity and ecological stability, while nitrogen biostimulation promoted PAH dissipation by stimulating indigenous soil degrading microbes, including fungi and key bacteria in the soil co-occurrence networks, ensuring the ecological diversity of soil microorganisms. The combination of both approaches proved to be the most effective strategy, maintaining a high degradation efficiency and relatively stable soil biodiversity through the secretion of lignin hydrolytic enzymes by fungi, and stimulating the reproduction of soil native degrading microbes, especially the key degraders in the co-occurrence networks. Our findings provide a fresh perspective of the synergy between fungal bioaugmentation and nitrogen biostimulation, highlighting the potential of this combined bioremediation approach for in situ PAH-contaminated soils.


Asunto(s)
Fenantrenos , Hidrocarburos Policíclicos Aromáticos , Contaminantes del Suelo , Contaminantes del Suelo/metabolismo , Hidrocarburos Policíclicos Aromáticos/análisis , Biodegradación Ambiental , Suelo , ADN , Microbiología del Suelo
15.
Food Chem ; 446: 138875, 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-38430772

RESUMEN

Reliable monitoring of nitroimidazoles (NDZs) is of great significance to public health. Herein, an azo-linked porous organic polymer (Res-POPs) was prepared by green synthesis method using natural resveratrol as monomer for the first time. Using Res-POPs as sorbent, a facile method coupling solid-phase extraction with high performance liquid chromatography-diode array detection was developed for effective detecting NDZs. The method achieved good linearities (0.06 âˆ¼ 100 ng mL-1 for water, 1.8 âˆ¼ 200 ng g-1 for shrimp, and 1.5 âˆ¼ 200 ng g-1 for Basa fish) with determination coefficients above 0.995, low detection limits (0.02 âˆ¼ 0.05 ng mL-1, 0.60 âˆ¼ 1.00 ng g-1 and 0.50 âˆ¼ 0.90 ng g-1 for water, shrimp and Basa fish), high method recovery (85 %∼114 %) and relative standard deviations below 8.2 %. The results demonstrated the superiority and the promising potential of the established method for detection of NDZs compared with the reported method.


Asunto(s)
Nitroimidazoles , Agua , Animales , Nitroimidazoles/análisis , Polímeros , Porosidad , Cromatografía Líquida de Alta Presión , Extracción en Fase Sólida/métodos , Límite de Detección
16.
Plast Reconstr Surg Glob Open ; 12(1): e5525, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38204875

RESUMEN

Background: Letibotulinum toxin A has an established efficacy and safety profile for aesthetic treatment of glabellar wrinkles. This study was conducted to demonstrate the noninferiority of letibotulinum toxin A versus onabotulinum toxin A in improving the appearance of moderate-to-severe glabellar wrinkles in Chinese patients. Methods: This phase-III multicenter, randomized, parallel positive control, double-blinded study compared the efficacy and safety of letibotulinum toxin A and onabotulinum toxin A. Eligible participants were randomized 3:1 to receive 20 U of letibotulinum toxin A or onabotulinum toxin A and were observed for 16 weeks postinjection. The primary endpoint was noninferiority in the proportion of study participants receiving a score of 0 or 1 for glabellar wrinkles on a four-point photographic evaluation scale, as assessed by an institution evaluator at maximum frown at week 4. Secondary endpoints included assessments at rest, photographic assessment of efficacy, and subjective self-assessment of the study participants. Results: The proportion of participants (N = 500) receiving a score of 0 or 1 at maximum frown by the institution evaluator at week 4 was 88.49% for letibotulinum toxin A and 87.39% for onabotulinum toxin A (difference, 1.10%; 95% confidence interval, -5.02 to 8.82; P = 0.7469). No significant differences were observed between the treatments for secondary efficacy or safety endpoints. Participants' self-assessment and satisfaction tended to be higher for letibotulinum toxin A than onabotulinum toxin A. Conclusion: Letibotulinum toxin A is noninferior to onabotulinum toxin A in improving the appearance of moderate-to-severe glabellar wrinkles in Chinese patients.

17.
Anal Chim Acta ; 1260: 341222, 2023 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-37121655

RESUMEN

Triazine herbicides have been widely detected in water resources and food, which poses a potential hazard to both ecosystem and human health. Due to their high polarity, conventional adsorbents have limitations for their extractions. Herein, for the effective magnetic extraction of triazine herbicides, a novel and effective magnetic adsorbent was prepared with a satisfactory extraction performance. In the experiments, five porous organic frameworks (POFs) with hydroxyl functional groups were synthesized by diazo-coupling reactions in aqueous solution with ß-cyclodextrin (ß-CD) as a green monomer. After evaluation of the five POFs, the DDM-CD-POF, which was synthesized with 4'4-diaminodiphenylmethane (DDM) and ß-CD, showed the largest specific surface area and the best adsorption capacity for the five triazine herbicides. Then, it was magnetized by introducing Fe3O4@SiO2 into it to prepare a magnetic adsorbent (M-DDM-CD-POF) to facilitate separation and recycling. Finally, the M-DDM-CD-POF-based magnetic solid-phase extraction in combination with high performance liquid chromatographic detection method was established for the quantitative determination of the triazine herbicides in environmental water and watermelon juice samples. The current strategy showed low limits of detection of 0.03-0.11 ng mL-1 for environmental water and 0.07-0.22 ng mL-1 for watermelon juice sample. The method recoveries for spiked samples ranged from 84.0% to 113.0% with the relative standard deviations ≤8.8%. This work provides a new approach for the detection of the triazine herbicides with good application prospect.


Asunto(s)
Herbicidas , Agua , Humanos , Cromatografía Líquida de Alta Presión , Ecosistema , Herbicidas/análisis , Límite de Detección , Fenómenos Magnéticos , Porosidad , Dióxido de Silicio , Extracción en Fase Sólida/métodos , Triazinas/química , Bebidas
18.
ACS Appl Mater Interfaces ; 15(46): 53189-53197, 2023 Nov 22.
Artículo en Inglés | MEDLINE | ID: mdl-37946326

RESUMEN

A single-atom catalyst (Fe SAs/-N-C) with excellent stability and conductivity was strategically fabricated via high-temperature calcination using the NiFe layered double hydroxide (LDH)/ZIF-8 composite as precursors. With the help of Ni as a catalyst, a great number of carbon nanotubes were produced whereby the isolated carbon bulks were interconnected to form an "island-bridge"-like 3D network structure, which greatly enhanced the exposure of active sites and the electron transfer. Accordingly, caffeic acid (CA) with versatile biological and pharmacological activities was chosen as the model analyte. The Fe SAs/-N-C with Fe-N4 as the catalytic active site was employed to establish the electrochemical sensing of CA with satisfactory sensitivity, selectivity, and long-term stability. This work expands the application range of single-atom catalysts and contributes a significant reference for the synthesis of hybrid double-atom catalysts.

19.
Food Chem ; 404(Pt B): 134652, 2023 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-36283305

RESUMEN

A novel hypercrosslinked polymer (API-HCP) was synthesized using as monomer for the first time. API-HCP exhibited high adsorption affinity toward chlorophenols due to the hydrogen bond, halogen bond and π-stacking interactions. With API-HCP as adsorbent, an efficient solid phase extraction method coupled with high performance liquid chromatography (SPE-HPLC) was established for the sensitive detection of chlorophenols in water and honey samples. Under the optimum conditions, the method provided a good linear response in the range of 0.07-100 ng mL-1 for water and 1.7-500 ng g-1 for honey sample. High sensitivity was achieved, with detection limits (S/N = 3) of 0.02-0.07 ng mL-1 for water and 0.5-1.5 ng g-1 for honey samples. The method recoveries for spiked sample were between 84.0 % and 116.0 %, with relative standard deviations ≤6.1 %. The API-HCP based SPE-HPLC method provided a robust platform for sensitive determination of chlorophenols in water and honey samples.


Asunto(s)
Clorofenoles , Miel , Clorofenoles/análisis , Miel/análisis , Polímeros/química , Agua/química , Porosidad , Extracción en Fase Sólida/métodos , Cromatografía Líquida de Alta Presión/métodos , Límite de Detección
20.
Anal Chim Acta ; 1238: 340638, 2023 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-36464452

RESUMEN

Sensitive, accurate, and simultaneous determination of nitrobenzene compounds (NBs) in environmental water samples is of great significance due to their high risk to human health. In this work, a new triazine-based hyper-crosslinked polymer named CC-Py was constructed via the Friedel-Crafts reaction between cyanuric chloride (CC), pyridine (Py) and 1,2-dichloroethane. Due to its excellent stability, high surface area and hydrophilic-lipophilic (amphiphilic) structure, the CC-Py exhibited a high affinity toward the NBs (nitrobenzene, 2-nitrotoluene, 2,6-dimethylnitrobenzene, 3-nitrotoluene, 4-nitrotoluene, 3-nitrochlorobenzene, 4-nitrochlorobenzene, 2-nitrochlorobenzene, 2,4-dimethylnitrobenzene, 3-nitrobromobenzene, 4-nitrobromobenzene and 4-nitroiodobenzene). Then, a CC-Py based solid-phase microextraction coupled with gas chromatography-flame ionization detection was developed to detect the twelve NBs in real water samples. The results showed that the method had low limits of detection (0.20-0.50 µg L-1), good reproducibility (relative standard deviations (RSDs) < 8.6%) and high enrichment factors (967-1590). The recoveries for the NBs in six different types of water samples were between 90% and 111% with the RSDs less than 7.5%. This work provides a facile and sensitive method for the determination of trace level of NBs in real water samples.


Asunto(s)
Polímeros , Triazinas , Humanos , Reproducibilidad de los Resultados , Nitrobencenos , Agua
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