RESUMEN
Immunodeficiency can disrupt normal physiological activity and function. In this study, donkey bone collagen peptide (DP) and its iron chelate (DPI) were evaluated their potential as immunomodulators in cyclophosphamide (Cytoxan®, CTX)-induced Balb/c mice. The femoral tissue, lymphocytes, and serum from groups of mice were subjected to hematoxylin and eosin (H&E) staining, methylthiazolyldiphenyl-tetrazolium bromide (MTT) cell proliferation assays, and enzyme-linked immunosorbent assay (ELISA), respectively. Furthermore, a non-targeted metabolomics analysis based on UPLC-MS/MS and a reverse transcription polymerase chain reaction (RT-qPCR) technology were used to explore the specific metabolic pathways of DPI regulating immunocompromise. The results showed that CTX was able to significantly reduce the proliferative activity of mouse splenic lymphocytes and led to abnormal cytokine expression. After DP and DPI interventions, bone marrow tissue damage was significantly improved. In particular, DPI showed the ability to regulate the levels of immune factors more effectively than Fe2+ and DP. Furthermore, metabolomic analysis in both positive and negative ion modes showed that DPI and DP jointly regulated the levels of 20 plasma differential metabolites, while DPI and Fe2+ jointly regulated 14, and all 3 jointly regulated 10. Fe2+ and DP regulated energy metabolism and pyrimidine metabolism pathways, respectively. In contrast, DPI mainly modulated the purine salvage pathway and the JAK/STAT signaling pathway, which are the key to immune function. Therefore, DPI shows more effective immune regulation than Fe2+ and DP alone, and has good application potential in improving immunosuppression.
Asunto(s)
Colágeno , Ciclofosfamida , Equidae , Quelantes del Hierro , Ratones Endogámicos BALB C , Animales , Colágeno/metabolismo , Quelantes del Hierro/farmacología , Ratones , Proliferación Celular/efectos de los fármacos , Péptidos/farmacología , Linfocitos/efectos de los fármacos , Linfocitos/metabolismo , Inmunosupresores/farmacología , Metabolómica , Citocinas/metabolismo , Masculino , Huesos/efectos de los fármacos , Huesos/metabolismo , Terapia de InmunosupresiónRESUMEN
Phytochemical studies on cigar tobacco leaves led to the isolation of 18 ionone-type compounds, including previously undescribed cigatobanes E (1) and F (2). Additionally, compounds vomifoliol acetate (3), dehydrovomifoliol (4), 8,9-dihydromegastigmane-4,6-diene-3-one (5), 7α,8α-epoxyblumenol B (6), 3-oxoactinidol (12), and loliolide acetate (15), 4ß-hydroxy-dihydroactinidiolide (17), were found in tobacco leaves for the first time. The structural elucidation of all compounds was accomplished through rigorous spectral analysis.
Asunto(s)
Nicotiana , Hojas de la Planta , Hojas de la Planta/química , Estructura Molecular , Nicotiana/química , Norisoprenoides/químicaRESUMEN
Immobilization of imidazole molecules as proton carriers into MOFs to facilitate proton conduction is a general strategy for developing high proton conductive materials. Herein, we designed two imidazole substituted phthalic acid ligands and constructed two novel MOFs, {[Zr6(OH)16(H3L1)4]Cl8·20H2O}n [Zr-MOF; H3L1 = 2-(1H-imidazol-4-yl) methylaminoterephthalic acid] and {Gd(HCOO)(H2L2)2}n [Gd-MOF; H3L2 = 5-(1H-imidazol-4-yl)methylaminoisophthalic acid] and fully studied their porous nature, stability and water-assisted proton conduction. The resulting Zr-MOF exhibits a high proton conductivity of 1.82 × 10-2 S cm-1 at 98% RH and 80 °C, while Gd-MOF has a proton conductivity of 3.01 × 10-3 S cm-1 at 98% RH and 60 °C.
RESUMEN
Ameloblastoma (AM) is characterised by local aggressiveness and bone resorption. To our knowledge, the proteomic profile of bone adjacent to AM has not previously been explored. We therefore looked at the differential proteins in cancellous bone (CB) adjacent to AM and normal CB from the mandible. CB proteins were extracted, purified, quantified, and analysed by liquid chromatography-mass spectrometry (LC-MS) using samples from five patients with AM. These proteins were further investigated using gene ontology for additional functional annotation and enrichment. Proteins that met the screening requirements of expression difference ploidy > 1.5-fold (upregulation and downregulation) and p < 0.05 were subsequently deemed differential proteins. Immunohistochemical staining was performed to confirm the above findings. Compared with normal mandibular CB, 151 differential proteins were identified in CB adjacent to the mandibular AM. These were mainly linked to cellular catabolic processes, lipid metabolism, and fatty acids (FA) metabolism. LC-MS and immunohistochemistry showed that CD36 was one of the notably decreased proteins in CB bordering the AM compared with normal mandibular CB (p = 0.0066 and p = 0.0095, respectively). CD36 expression in CB correlates with bone remodelling in AM, making CD36 a viable target for therapeutic approaches.
Asunto(s)
Ameloblastoma , Remodelación Ósea , Antígenos CD36 , Proteómica , Humanos , Ameloblastoma/metabolismo , Ameloblastoma/patología , Remodelación Ósea/fisiología , Antígenos CD36/metabolismo , Antígenos CD36/análisis , Neoplasias Mandibulares/metabolismo , Neoplasias Mandibulares/patología , Cromatografía Liquida , Hueso Esponjoso/metabolismo , Metabolismo de los Lípidos/fisiología , Adulto , Femenino , Masculino , Mandíbula/metabolismo , Espectrometría de Masas , Ácidos Grasos/metabolismo , Persona de Mediana Edad , Proteoma/análisisRESUMEN
OBJECTIVES: Ameloblastoma (AM), a locally aggressive tumor with extensive growth capacity, causes significant damage to the jaw and affects facial appearance. Although the high prevalence of BRAF V600E mutation in AM is known, its specific impacts on patients with AM remain unclear. Thus, the present study investigated the role of BRAF V600E mutation, thereby focusing on its impact on AM invasion and growth. MATERIALS AND METHODS: Immunohistochemical analysis was used to compare BRAF V600E, MMP2, MMP9, and Ki-67 expressions in AM (n = 49), normal oral mucosa (NOM) (n = 10), and odontogenic keratocyst (OKC) (n = 15) tissues. AM was further classified according to the presence or absence of BRAF V600E. The relationship between BRAF V600E and invasion as well as growth was evaluated. In addition, correlation analysis was performed using immunohistochemistry and confirmed via double-labeling immunofluorescence. Finally, comparative analyses using mass spectrometry, immunohistochemistry, and immunofluorescence were performed to explore and identify underlying mechanisms. RESULTS: AM exhibited a higher incidence of BRAF V600E mutation than NOM and OKC. BRAF V600E expression was positively correlated with the invasion-associated proteins MMP2 and MMP9 and the growth-related protein Ki-67. Proteomic data revealed that BRAF V600E primarily activates the MAPK signaling pathway in AM, particularly driving the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2). CONCLUSIONS: In summary, the findings suggested that the BRAF V600E mutation enhances the invasion and growth abilities of AM via the MAPK/ERK signaling pathway. Thus, targeting BRAF V600E or the MAPK/ERK pathway may be a potential AM therapy.
RESUMEN
SCPEEK@MOF proton exchange membranes, where SCPEEK is sulfinyl chloride polyether ether ketone and MOF is a metal-organic framework, were prepared by doping Fe-MIL-101-NH2 into polymers. The amino group in the MOF and the -SOCl2 group in thionyl chloride polyether ether ketone cross-link to form a covalent bond through the Hinsberg reaction, and the prepared composite membrane has stronger stability than other electrostatic interactions and simple physical doping composite membranes. The formation of covalent bonds improves the water absorption of the composite membrane, which makes it easy for water molecules to form hydrogen bonds. Moreover, SPEEK as a proton conductive polymer and the synergy of MOFs improve the proton conductivity of composite membranes. The composite membranes were characterized by Fourier transform infrared spectroscopy, powder X-ray diffraction, scanning electron microscopy, and atomic force microscopy. The swelling rate, water absorption, mechanical stability, ion exchange capacity, and proton conductivity of the pure sulfonated polyether ether ketone (SPEEK) membrane were compared with those of the mechanically doped SPEEK/MOF membrane and the composite membrane SCPEEK@MOF doped with different ratios of Fe-MIL-101-NH2, and all of the SCPEEK@MOF showed superior performance. When the Fe-MIL-101-NH2 loading rate of the composite membrane is 2%, the proton conductivity of the composite membrane can reach 0.202 S cm-1 at 363 K and a 98% relative humidity, which is much higher than that of the SPEEK/MOF membrane obtained by simple physical doping under the same conditions.
RESUMEN
Engineering of genetic networks with artificial signaling pathways (ASPs) can reprogram cellular responses and phenotypes under different circumstances for a variety of diagnostic and therapeutic purposes. However, construction of ASPs between originally independent endogenous genes in mammalian cells is highly challenging. Here we report an amplifiable RNA circuit that can theoretically build regulatory connections between any endogenous genes in mammalian cells. We harness the system of catalytic hairpin assembly with combination of controllable CRISPR-Cas9 function to transduce the signals from distinct messenger RNA expression of trigger genes into manipulation of target genes. Through introduction of these RNA-based genetic circuits, mammalian cells are endowed with autonomous capabilities to sense the changes of RNA expression either induced by ligand stimuli or from various cell types and control the cellular responses and fates via apoptosis-related ASPs. Our design provides a generalized platform for construction of ASPs inside the genetic networks of mammalian cells based on differentiated RNA expression.
Asunto(s)
ARN Catalítico , Animales , ARN Catalítico/metabolismo , ARN/genética , ARN Mensajero/genética , ARN Mensajero/metabolismo , Apoptosis , Transducción de Señal , Redes Reguladoras de Genes , Mamíferos/metabolismoRESUMEN
Phytochemical investigation on cigar tobacco leaves led to four unknown sesquiterpenoids as well as nine reported ones. Among of them, 3-acetoxy-ß-damascone was first found in tobacco leaves. All the structures were elucidated by intensive spectroscopic analyses and X-ray diffraction. The relationship between the newly isolates and known ones was tried to describe.
Asunto(s)
Sesquiterpenos , Productos de Tabaco , Estructura Molecular , Difracción de Rayos X , Sesquiterpenos/químicaRESUMEN
Chronic HBV infection patients who do not conform to any of the usual immune states are regarded as 'grey zone' patients. We aimed to investigate the proportion of chronic HBV infection patients in the grey zone, and evaluate the clinical characteristics and liver pathological changes in grey zone patients. Clinical data of 1391 treatment-naive chronic HBV infection patients with liver biopsy were collected. Natural history of HBV infection was determined based on European Association for the Study of the Liver (EASL) 2017, American Association for the Study of Liver Diseases (AASLD) 2018 and Chinese 2019 guidelines for the prevention and treatment of chronic HBV infection. Significant liver histological changes and associated risk factors of normal ALT grey zone patients were analysed. According to EASL, AASLD and Chinese criteria, there were 50.0%, 28% and 37.4% chronic HBV infection patients in the grey zone. Among the 353 grey zone patients with normal ALT, 72.4% had significant liver histological changes. ALT (optimal cut-off value 25 IU/L) and HBV DNA (optimal cut-off value 18,000 IU/mL) were independent risk factors of significant liver histological abnormalities. In conclusion, a substantial proportion of grey zone patients with normal ALT have significant liver histological changes that can be predicted by levels of serum ALT and HBV DNA. These results provide guidance of antiviral treatment in grey zone patients.
Asunto(s)
Hepatitis B Crónica , Humanos , Hepatitis B Crónica/tratamiento farmacológico , Virus de la Hepatitis B/genética , ADN Viral , Cirrosis Hepática , Alanina Transaminasa , Antígenos e de la Hepatitis BRESUMEN
A sulfonated poly(ethersulfone) (SPES)-metal-organic framework (MOF) film with excellent proton conductivity was synthesized by anchoring UiO-66-NH2 to the main chain of the aromatic polymer through the Hinsberg reaction. The chemical bond was formed between the amino group in MOFs and the -SO2Cl group in chlorosulfonated poly(ethersulfones) to conduct protons in the proton channel of the membrane, making the membrane have excellent proton conductivity. UiO-66-NH2 is successfully prepared as a result of the consistency of the experimental and simulated powder X-ray diffraction (PXRD) patterns of MOFs. The existence of absorption peaks of characteristic functional groups in Fourier transform infrared (FTIR) spectra proved the successful preparation of SPES, PES-SO2Cl, and a composite film. The results of the AC impedance test indicate that the composite film with a 3% mass fraction has the best proton conductivity of 0.215 S·cm-1, which is 6.2 times higher than that of the blended film without a chemical bond at 98% RH and 353 K. To our knowledge, there are rarely any reports on the preparation of a composite membrane by directly linking MOFs and the membrane matrix with chemical bonds. This work provides a good way to synthesize the highly conductive proton exchange film.
RESUMEN
The well-defined 2D or 3D structure of covalent organic frameworks (COFs) makes it have great potential in photoelectric conversion and ions conduction fields. Herein, a new donor-accepter (D-A) COF material, named PyPz-COF, constructed from electron donor 4,4',4â³,4'â³-(pyrene-1,3,6,8-tetrayl)tetraaniline and electron accepter 4,4'-(pyrazine-2,5-diyl)dibenzaldehyde with an ordered and stable π-conjugated structure is reported. Interestingly, the introduction of pyrazine ring endows the PyPz-COF a distinct optical, electrochemical, charge-transfer properties, and also brings plentiful CN groups that enrich the proton by hydrogen bonds to enhance the photocatalysis performance. Thus, PyPz-COF exhibits a significantly improved photocatalytic hydrogen generation performance up to 7542 µmol g-1 h-1 with Pt as cocatalyst, also in clear contrast to that of PyTp-COF without pyrazine introduction (1714 µmol g-1 h-1 ). Moreover, the abundant nitrogen sites of the pyrazine ring and the well-defined 1D nanochannels enable the as-prepared COFs to immobilize H3 PO4 proton carriers in COFs through hydrogen bond confinement. The resulting material has an impressive proton conduction up to 8.10 × 10-2 S cm-1 at 353 K, 98% RH. This work will inspire the design and synthesis of COF-based materials with both efficient photocatalysis and proton conduction performance in the future.
RESUMEN
Xiaoheiyao is the rhizome of Inula nervosa Wall., a traditional spice and medicinal herb in China. In this study, the creatinine inhibitor from Xiaoheiyao extract and also the effects and mechanism on the production of heterocyclic aromatic amines (HAAs) were investigated. Xiaoheiyao extract inhibited the total contents of seven detected HAAs in grilled beef patties, particularly aminoimidazole-azaarenes (AIAs) in a dose-dependent manner, reaching a maximum inhibition rate of 62% for total HAAs and 73% for AIAs. The most effective subfraction of Xiaoheiyao extract (IER80) contained abundant potential creatinine inhibitors, as revealed by immobilized creatinine probe, HPLC and UPLC-MS/MS analyses. Moreover, electrophilic p-coumaric acid derivatives were discovered from IER80 by feature based molecular networking. p-Coumaric acid was demonstrated to inhibit the contents of total HAAs and AIAs in grilled beef patties and model system. Quantitative analyses of the precursor and intermediates of AIAs in model system revealed that p-coumaric acid mainly affected the generation of AIAs by inhibiting creatinine.
Asunto(s)
Compuestos Heterocíclicos , Inula , Bovinos , Animales , Creatinina , Compuestos Heterocíclicos/análisis , Cromatografía Liquida , Rizoma/química , Espectrometría de Masas en Tándem , Aminas/análisis , Extractos Vegetales , Culinaria , Carne/análisisRESUMEN
Mammalian target of rapamycin (mTOR) inhibitors (sirolimus or everolimus) have been demonstrated effective in reducing the size of tuberous sclerosis complex (TSC)-associated retinal astrocytic hamartoma (RAH) in short term. To investigate the long-term efficacy and safety of sirolimus on TSC-associated RAH, 13 TSC-associated RAH patients (59 RAH lesions) who received sirolimus therapy for at least 2 years were retrospectively enrolled in this study. Changes in the maximal thickness (MT) of RAH on optical coherence tomography and the longest base diameter (LBD) of RAH on color fundus photography were assessed. The results showed that for a mean follow-up of 39 months, sirolimus was associated with a mean reduction of 14.6% in MT and 6.8% in LBD of RAHs. The main impacts of sirolimus occurred within the first 6-12 months, with 14.8% reduction in MT and 4.7% reduction in LBD. Mouth ulceration (10 [76.9%]) and acne (9 [69.2%]) were the most common adverse events. These follow-up data support the long-term use of sirolimus in TSC-associated RAH patients, and persistent use of sirolimus possibly prevents tumor regrowth.
RESUMEN
This study analyzed the outcome indicators in randomized controlled trial(RCT) on Chinese medicine as adjuvant therapy for severe pneumonia in the past years, laying a foundation for the design of clinical trials on and construction of core outcome set(COS) for severe pneumonia. To be specific, related RCT was retrieved from CNKI, Wanfang, VIP, SinoMed, PubMed, EMbase, Cochrane Library, Web of Science, Chinese Clinical Trial Registry, and ClinicalTrials.gov(from January 1,2011 to April 9,2022). Then data in the trials were extracted, and the quality of included RCT was assessed according to Cochrane handbook, followed by descriptive analysis of the use of outcome indicators. A total of 11 833 articles were screened out, and finally 34 RCTs were included(2 were protocols). The included trials involved 109 outcome indicators with emergence frequency of 320, which were mainly classified into 9 categories: physicochemical indicators(54, frequency 167), time to achieve the efficacy(15, frequency 38), clinical effective rate(10, frequency 36), quality of life(11, frequency 35), symptoms and signs(7, frequency 18), traditional Chinese medicine(TCM) syndrome(4, frequency 13), safety(3, frequency 8), economic evaluation(1, frequency 1), other indicators(4, frequency 4). The indicators with high frequency followed the order: total effective rate, arterial oxygen partial pressure, C-reactive protein, white blood cell count, arterial blood carbon dioxide partial pressure. A total of 5 articles(14.71%) reported the main outcome indicators and 11 articles(32.35%) adopted the efficacy on TCM syndromes as the outcome indicator. There are many problems in the selection of outcome indicators in RCT on the treatment of severe pneumonia with Chinese medicine, mainly manifested as the disregard of clinical endpoint indicators, the inappropriate selection of surrogate indicators, and the non-standard evaluation criteria for the efficacy on TCM syndrome. It is suggested that the evaluation system for the efficacy of Chinese medicine on severe pneumonia should be established in accordance with the method for international COS to improve the quality of clinical trials.
Asunto(s)
Medicamentos Herbarios Chinos , Neumonía , Humanos , Medicina Tradicional China , Medicamentos Herbarios Chinos/uso terapéutico , Calidad de Vida , Terapia Combinada , Neumonía/tratamiento farmacológicoRESUMEN
Food-derived electrophilic compounds (FECs) are small molecules with electrophilic groups with potential cytoprotective effects. This study investigated the differential effects of six prevalent FECs on colitis in dextran sodium sulfate (DSS)-induced mice and the underlying relationship with molecular characteristics. Fumaric acid (FMA), isoliquiritigenin (ISO), cinnamaldehyde (CA), ferulic acid (FA), sulforaphane (SFN), and chlorogenic acid (CGA) exhibited varying improvements in colitis on clinical signs, colonic histopathology, inflammatory and oxidative indicators, and Nrf2 pathway in a sequence of SFN, ISO > FA, CA > FMA, CGA. Representative molecular characteristics of the "penetration-affinity−covalent binding" procedure, logP value, Keap1 affinity energy, and electrophilic index of FECs were theoretically calculated, among which logP value revealed a strong correlation with colitis improvements, which was related to the expression of Nrf2 and its downstream proteins. Above all, SFN and ISO possessed high logP values and effectively improving DSS-induced colitis by activating the Keap1−Nrf2 pathway to alleviate oxidative stress and inflammatory responses.
RESUMEN
A series of heterometallic tetranuclear clusters, Ln2Ni2(NO3)4L4(µ3-OCH3)2·2(CH3CN) (Ln = Gd(1), Tb(2), Dy(3), Ho(4), Er(5); HL = methyl 3-methoxysalicylate), were synthesized solvothermally. The intramolecular synergistic effect of two metal centers of Ln(III) and Ni(II) and the exposed multimetallic sites serving as Lewis acid activators greatly increase the efficiency of the CO2 conversion, and the yield for cluster 3 can be achieved at 96% at atmospheric pressure and low temperature. In particular, the self-assembly multimetal center with polydentate ligand shows good generality and enhanced recyclability. The design of such 3d-4f heterometallic clusters provides an effective strategy for the conversion of CO2 under greener conditions. Meanwhile, magnetic investigations indicate that cluster 1 is a good candidate for magnetic refrigerant materials with a relatively large magnetocaloric effect (MCE) (-ΔSm = 28.5 J kg-1 K-1 at 3.0 K and 7.0 T), and cluster 3 shows single-molecular magnet behavior under zero dc field. Heterometallic clusters with special magnetic properties and good catalytic behavior for the conversion of CO2 are rare. Thus, they are potential bifunctional materials applied in practice.
RESUMEN
Background: Interleukin 8 (IL-8) is a chemotactic cytokine released by various cells including leukocytes, endothelial cells, and epithelial cells. IL-8 has multiple functions in inflammation, tumour invasion, or angiogenesis. Human odontogenic cystic lesions are chronic and frequently inflamed. Tissue-derived extracellular vesicles (Ti-EVs) are widely present in various tissues and could more accurately reflect the characteristics of the primary tissue. However, the involvement of IL-8 in Ti-EVs of human odontogenic lesions is still unclear. This study aimed to explore the expression of IL-8 in Ti-EVs of human odontogenic lesions and the potential roles of Ti-EVs that carried IL-8. Methods: Fresh tissue samples of dentigerous cyst (DC, n = 5) and odontogenic keratocyst (OKC, n = 5) were collected for Ti-EVs isolation. Ti-EVs were characterised by transmission electron microscopy and nano-flow cytometry analysis. The cytokine profile of Ti-EVs was explored by cytokine antibody array. The IL-8 expression was examined by immunochemical staining in tissue of odontogenic lesions (DC, n =12; OKC, n =28). Antioxidants (N-acetyl-L-cysteine and diphenyleneiodonium) were employed to treat HaCaT cells, and the expression of IL-8 was detected by enzyme-linked immunosorbent assay. The gene expression of MMP9 was explored by quantitative real-time polymerase chain reaction in co-culture system of fibroblasts of OKC with Ti-EVs. Results: Compared with DC, the expression of IL-8 in Ti-EVs and fixed tissue specimens of OKC was markedly upregulated. The antioxidants decreased the expression level of IL-8 protein in the supernatant of HaCaT cells. The Ti-EVs treatment (10 µg/ml) of fibroblasts significantly induced the MMP9 mRNA expressions in OKC fibroblasts. Conclusions: IL-8 was upregulated in Ti-EVs of OKC and might be involved in the tissue destruction of OKC.
Asunto(s)
Quiste Dentígero , Interleucina-8/metabolismo , Quistes Odontogénicos , Tumores Odontogénicos , Quiste Dentígero/metabolismo , Quiste Dentígero/patología , Células Endoteliales/metabolismo , Humanos , Interleucina-8/genética , Metaloproteinasa 9 de la Matriz , Quistes Odontogénicos/metabolismoRESUMEN
A metal-organic framework, {Zn3(BTB)2(µ3-OH)[(CH3)2NH2](H2O)}n (1), was synthesized based on H3BTB (1,3,5-tri(4-carboxyphenyl)benzene). An AC impedance test proves that 1 has a relatively high conductivity performance of 1.52 × 10-3 S·cm-1 at 338 K and 98% RH. The proton conductivity of the composite film 1@CS-9 (CS = chitosan) reaches 1.84 × 10-1 S·cm-1 at 328 K and 98% RH. In addition, 1 is discovered to have a good adsorption effect on iodine vapor, and the adsorption capacity reaches 726 mg·g-1. The multifunctionality caused by dimethylamine cations was investigated for the first time, which has implications for multifunctionality generated by host-guest molecules.
RESUMEN
Antibiotic residues contained in poultry eggs pose threat to human health. However, the classes and concentrations of antibiotics in poultry egg in southwestern China is unknown due to insufficient monitoring and research. A total of 513 egg samples were collected from supermarkets and farm markets in Kunming city in 2020 and the levels of 7 antibiotics were analyzed using ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method. The linear correlation coefficients were above 0.990 for all antibiotics tested. The limits of detection and limits of quantification in poultry eggs were 0.002 to 0.010 µg/g and 0.007 to 0.033 µg/g, respectively. The average recoveries of the 7 analytes from poultry egg samples were 80.00 to 128.01%, with relative standard deviations of less than 13.97%. A total of 93 (18.13%) samples tested positive for antibiotics, with the highest concentration being 2.48 µg/g. The concentration range of ofloxacin, danofloxacin, difloxacin, sulfadimethoxine, sulfamonomethoxine, sulfamethoxypyridazine, and sulfamethoxazole in poultry eggs was 0.01 to 0.37 µg/g, 0.06 to 0.48 µg/g, 0.05 to 0.29 µg/g, 0.03 to 0.16 µg/g, 0.06 to 1.00 µg/g, 0.05 to 0.37, and 0.07 to 2.48 µg/g, respectively. Sulfamonomethoxine was detected from hen eggs with the highest concentration level at 1.00 µg/g. Sulfamethoxazole was detected with the highest concentration level from both duck and quail eggs, at 1.87 and 2.48 µg/g, respectively. The antibiotic with the highest residue level in pheasant eggs was danofloxacin, which was 0.37 µg/g. Sulfamethoxypyridazine was identified in 30 samples with the highest positive rate of 5.85%, sulfadimethoxine was identified in 3 samples with the lowest positive rate of 0.58%. We observed that 7 targeted antibiotic residues in quail eggs and 3 targeted antibiotic residues in pheasant eggs. We also found that there were antibiotic residues in free-range hen eggs and the concentration was not low. The antibiotic with the highest residue level in free-range eggs was sulfamonomethoxine, which was 1.00 µg/g. These findings suggest that continual antibiotic residue monitoring of poultry eggs is essential in China.
Asunto(s)
Residuos de Medicamentos , Sulfametoxipiridazina , Sulfamonometoxina , Animales , Antibacterianos/análisis , Pollos , Cromatografía Líquida de Alta Presión/veterinaria , Residuos de Medicamentos/análisis , Huevos/análisis , Femenino , Fluoroquinolonas , Contaminación de Alimentos/análisis , Óvulo/química , Aves de Corral , Extracción en Fase Sólida/veterinaria , Sulfadimetoxina/análisis , Sulfametoxazol/análisis , Sulfametoxipiridazina/análisis , Sulfamonometoxina/análisis , Sulfonamidas/análisis , Espectrometría de Masas en Tándem/métodos , Espectrometría de Masas en Tándem/veterinariaRESUMEN
Metal-organic frameworks have great potential in the field of proton conducting materials and fluorescent probes due to their structural tunability and designability. A novel water-stable metal organic framework material [Cd2(Hdpb)(H2O)3] (Cd-MOF) was synthesized based on H5dpb (H5dpb = 3,5-diphosphonobenzoic acid) and Cd2+ ions. Cd2+ ions are connected with phosphonates and carboxyl groups of H5dpb to form an infinitely extended 1D chain, which is further connected by the Hdpb4- ligand and coordinated water to form a three-dimensional network structure. There are hydrogen bond networks in the 3D structure of the Cd-MOF, which are favorable for proton transfer, achieving its maximum proton conductivity of 2.97 × 10-3 S cm-1 at 338 K and 98% relative humidity (RH). To realize its application in fuel cells, the Cd-MOF was introduced into the chitosan (CS) matrix, and a series of composite membranes (Cd-MOF@CS-X) with high proton conductivity were obtained. The results of AC impedance show that the proton conductivity of Cd-MOF@CS-5 reaches 3.55 × 10-1 S cm-1 at 358 K and 98% RH, which is comparable to the highest values reported for MOF-polymer complexes. Moreover, the Cd-MOF can be used as a selective fluorescent probe for pyridine detection, and its detection limit can reach 1.0 × 10-6 M. A bifunctional MOF with proton conduction and pyridine recognition is reported for the first time, and has important reference value for the practical application of functional MOFs in both electrochemical and luminescence sensing.