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BACKGROUND: Obesity is a serious public health issue worldwide, which is a risk factor of cardiovascular disorders. Obesity has been shown to be associated with subclinical myocardial injury, increasing the risk of heart failure. Our study aims to explore novel mechanisms underlying obesity-induced myocardial injury. METHODS: Mice were fed a high-fat diet (HFD) to establish a mouse model of obesity, and serum levels of TG, TCH, LDL, CK-MB, LDH, cTnI and BNP were examined. Inflammatory response was evaluated by determining the expression and secretion of proinflammatory cytokines IL-1ß and TNF-α. Macrophage infiltration in the heart was examined by IHC staining, and H&E staining was applied to evaluate myocardial injury. Primary peritoneal macrophages were isolated from mice and treated with palmitic acid (PA). Macrophage polarization was evaluated by determine the expression of CCL2, iNOS, CD206 and arginase I via Western blot, RT-qPCR, and flow cytometry. Co-IP assays were performed to examine the interaction between LEAP-2, GHSR and ghrelin. RESULTS: Hyperlipidemia, increased proinflammatory cytokines and myocardial injury were observed in mice with obesity, and silencing of LEAP-2 ameliorated HFD-induced hyperlipidemia, inflammation, and myocardial injury. Moreover, HFD-induced macrophage infiltration and M1 polarization were reversed by LEAP-2 knockdown in mice. Furthermore, silencing of LEAP-2 suppressed PA-induced M1 polarization but enhanced M2 polarization in vitro. LEAP-2 interacted with GHSR in macrophages, and knockdown of LEAP-2 promoted the interaction of GHSR and ghrelin. Overexpression of ghrelin enhanced LEAP-1 silencing-mediated suppression of inflammatory response and upregulation of M2 polarization in PA-induced macrophages. CONCLUSION: Knockdown of LEAP-2 ameliorates obesity-induced myocardial injury via promoting M2 polarization.
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Ghrelina , Macrófagos , Animales , Ratones , Citocinas/metabolismo , Ghrelina/metabolismo , Inflamación/metabolismo , Macrófagos/metabolismo , Obesidad/complicaciones , Obesidad/genéticaRESUMEN
Diffusion is generally faster at higher temperatures. Here, a counterintuitive behavior is observed in that the movement of long-chain molecules slows as the temperature increases under confinement. This report confirms that this anomalous diffusion is caused by the "thermal resistance effect," in which the diffusion resistance of linear-chain molecules is equivalent to that with branched-chain configurations at high temperature. It then restrains the molecular transportation in the nanoscale channels, as further confirmed by zero length column experiments. This work enriches our understanding of the anomalous diffusion family and provides fundamental insights into the mechanism inside confined systems.
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6:2 Chlorinated polyfluoroalkyl ether sulfonate (F-53B) is a new type of perfluorinated and polyfluoroalkyl substance (PFAS) that is used extensively in industry and manufacturing. F-53B causes damage to multiple mammalian organs. However, the impacts of F-53B on bone are unknown. Maternal exposure to F-53B is of particular concern because of the vulnerability of the developing fetus and newborn to contaminants from the mother. The goal of this study was to examine the impacts of maternal F-53B exposure on bone growth and development in offspring and to explore its underlying mechanisms. Herein, C57BL/6â¯J mice were given free access to deionized water containing 0, 0.57, or 5.7â¯mg/L F-53B during pregnancy and lactation. F-53B exposure resulted in impaired liver function, decreased IGF-1 secretion, dysregulation of bone metabolism and disruption of the dynamic balance between osteoblasts and osteoclasts in male offspring. F-53B inhibits longitudinal bone growth and development and causes osteoporosis in male offspring. F-53B may affect the growth and development of offspring bone via the IGF-1/OPG/RANKL/CTSK signaling pathway. This study provides new insights for the study of short stature and bone injury caused by F-53B.
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Desarrollo Óseo , Lactancia , Exposición Materna , Ratones Endogámicos C57BL , Efectos Tardíos de la Exposición Prenatal , Animales , Femenino , Masculino , Embarazo , Ratones , Exposición Materna/efectos adversos , Desarrollo Óseo/efectos de los fármacos , Factor I del Crecimiento Similar a la Insulina/metabolismo , Fluorocarburos/toxicidad , Osteoprotegerina/metabolismo , Osteoclastos/efectos de los fármacos , Huesos/efectos de los fármacos , Osteoblastos/efectos de los fármacos , Ácidos Sulfónicos/toxicidadRESUMEN
BACKGROUND: Previous studies on the effects of microplastics (MPs) on bone in early development are limited. This study aimed to investigate the adverse effects of MPs on bone in young rats and the potential mechanism. METHODS: Three-week-old female rats were orally administered MPs for 28 days, and endoplasmic reticulum (ER) stress inhibitor salubrinal (SAL) and ER stress agonist tunicamycin (TM) were added to evaluate the effect of ER stress on toxicity of MPs. The indicators of growth and plasma markers of bone turnover were evaluated. Tibias were analyzed using micro-computed tomography (micro-CT). Histomorphological staining of growth plates was performed, and related gene expression of growth plate chondrocytes was tested. RESULTS: After exposure of MPs, the rats had decreased growth, shortened tibial length, and altered blood calcium and phosphorus metabolism. Trabecular bone was sparse according to micro-CT inspection. In the growth plate, the thickness of proliferative zone substantial reduced while the thickness of hypertrophic zone increased significantly, and the chondrocytes were scarce and irregularly arranged according to tibial histological staining. The transcription of the ER stress-related genes BIP, PERK, ATF4, and CHOP dramatically increased, and the transcription factors involved in chondrocyte proliferation, differentiation, apoptosis, and matrix secretion were aberrant according to RT-qPCR and western blotting. Moreover, the addition of TM showed higher percentage of chondrocyte death. Administration of SAL alleviated all of the MPs-induced symptoms. CONCLUSION: These results indicated that MPs could induce growth retardation and longitudinal bone damage in early development. The toxicity of MPs may attribute to induced ER stress and impaired essential processes of the endochondral ossification after MPs exposure.
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Estrés del Retículo Endoplásmico , Placa de Crecimiento , Microplásticos , Poliestirenos , Animales , Estrés del Retículo Endoplásmico/efectos de los fármacos , Placa de Crecimiento/efectos de los fármacos , Placa de Crecimiento/patología , Femenino , Ratas , Microplásticos/toxicidad , Poliestirenos/toxicidad , Ratas Sprague-Dawley , Osteogénesis/efectos de los fármacos , Condrocitos/efectos de los fármacos , Tibia/efectos de los fármacos , Tibia/patologíaRESUMEN
Jingmen virus (JMV) associated with ticks and vertebrates have been found to be related to human disease. We obtained the genome of a Jingmen tick virus (JMTV) strain from Rhipicephalus microplus in Guizhou province and compared the genomes of seven JMV species associated with ticks and vertebrates to understand the evolutionary relationships. The topology of the phylogenetic tree of segment 1 and segment 3 is similar, and segment 2 and segment 4 formed two different topologies, with the main differences being between Alongshan virus (ALSV), Takachi virus, Yanggou tick virus and Pteropus lylei jingmen virus (PLJV), and the possibility of genetic reassortment among these viruses. Moreover, we detected recombination within JMTV and between PLJV and ALSV. The genetic reassortment and recombination that occurs during cross-species transmission of these JMV associated with ticks and vertebrates not only complicates their evolutionary relationships, but also raises the risk of these viruses to humans.
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Garrapatas , Virus , Animales , Genómica , Filogenia , Vertebrados/genética , Virus/genéticaRESUMEN
BACKGROUND: To provide useful insights into measles elimination progress in China, measles surveillance data were reviewed, and the transmission patterns of measles viruses circulating in China during 1993-2021 were analyzed. METHODS: Measles incidence data from the National Notifiable Disease Reporting System of the China Center for Disease Control and Prevention were analyzed. A total of 17 570 strains were obtained from 30 of 31 provinces in mainland China during 1993-2021. The recommended genotyping window was amplified. Genotyping analysis was conducted for comparison with the reference strains. Phylogenetic analyses were performed to identify genetic relationships among different lineages within the genotypes. RESULTS: With high coverage of routine immunization and intensive supplementary immunization activities, measles incidence has shown a downward trend since 1993, despite 2 resurgences, reaching a historic low level in 2020-2021 (average 0.5 per million). During 1993-2021, 9 genotypes including domestic genotype H1; imported genotypes B3, D4, D8, D9, D11, G3, and H2; and vaccine-associated genotype A were identified. Among them, the genotype H1 strain circulated endemically in China for more than 25 years; the last strain was detected in Yunnan Province in September 2019. Multiple imported genotypes have been identified since 2009 showing different transmission patterns. Since April 2020, no imported strains have been detected, while vaccine-associated genotype A continues to be detected. CONCLUSIONS: The evidence of low incidence during 2020-2021 and virological surveillance data in this study confirm that China is currently approaching measles elimination.
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Virus del Sarampión , Sarampión , Humanos , Virus del Sarampión/genética , Genotipo , Filogenia , China/epidemiología , Sarampión/epidemiología , Sarampión/prevención & controlRESUMEN
Acid-catalyzed reactions inside zeolites are one type of broadly applied industrial reactions, where carbocations are the most common intermediates of these reaction processes, including methanol to olefins, alkene/aromatic alkylation, and hydrocarbon cracking/isomerization. The fundamental research on these acid-catalyzed reactions is focused on the stability, evolution, and lifetime of carbocations under the zeolite confinement effect, which greatly affects the efficiency, selectivity and deactivation of zeolite catalysts. Therefore, a profound understanding of the carbocations confined in zeolites is not only beneficial to explain the reaction mechanism but also drive the design of new zeolite catalysts with ideal acidity and cages/channels. In this review, we provide both an in-depth understanding of the stabilization of carbocations by the pore confinement effect and summary of the advanced characterization methods to capture carbocations in zeolites, including UV-vis spectroscopy, solid-state NMR, fluorescence microscopy, IR spectroscopy and Raman spectroscopy. Also, we clarify the relationship between the activity and stability of carbocations in zeolite-catalyzed reactions, and further highlight the role of carbocations in various hydrocarbon conversion reactions inside zeolites with diverse frameworks and varying acidic properties.
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Research background: The processing method generally affects the toxicity and biological activity of aged sorghum vinegar. This study investigates the changes in the intermediate Maillard reaction products of sorghum vinegar during ageing and the in vivo hepatoprotective effects of pure melanoidin obtained from it. Experimental approach: High-performance liquid chromatography (HPLC) and fluorescence spectrophotometry were utilized to quantify intermediate Maillard reaction products. The CCl4-induced liver damage in rats was used to evaluate the protective role of pure melanoidin in rat liver. Results and conclusions: Compared with the initial concentration, the 18-month ageing process caused a 1.2- to 3.3-fold increase in the concentrations of intermediate Maillard reaction products, i.e. 5-hydroxymethylfurfural (HMF), 5-methylfurfural (MF), methyglyoxal (MGO), glyoxal (GO) and advanced glycation end products (AGEs). The concentrations of HMF in the aged sorghum vinegar were 6.1-fold higher than the 450 µM limit standard for honey, implying the need for shortening the ageing of the vinegar in practice for safety concerns. Pure melanoidin (Mr>3.5 kDa) demonstrated significant protective effects against CCl4-induced rat liver damage, as evidenced by normalized serum biochemical parameters (transaminases and total bilirubin), suppressing hepatic lipid peroxidation and reactive oxygen species, as well as increasing glutathione amount and restoring antioxidant enzyme activities. Histopathological analysis revealed that melanoidin in vinegar reduced cell infiltration and vacuolar hepatocyte necrosis in rat liver. The findings demonstrated that a shortened ageing process should be considered in practice to ensure the safety of aged sorghum vinegar. Vinegar melanoidin is a potential alternative for the prevention of hepatic oxidative damage. Novelty and scientific contribution: This study demonstrates that the manufacturing process had a profound influence on the generation of vinegar intermediate Maillard reaction products. In particular, it revealed the in vivo hepatoprotective effect of pure melanoidin from aged sorghum vinegar, and provides insight into the in vivo biological activity of melanoidin.
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Zeolite nanosheets with excellent mass transfer are attractive, but their successful syntheses are normally resulted from a huge number of experiments. Here, we show the design of a small organic template for the synthesis of self-pillared pentasil (SPP) zeolite nanosheets from theoretical calculations in interaction energies between organic templates and pentasil zeolite skeletons. As expected, the SPP zeolite nanosheets with the thickness at 10-20 nm have been synthesized successfully. Characterizations show that the SPP zeolite nanosheets with about 90% MFI and 10% MEL structures have good crystallinity, the house-of-card morphology, large surface area, and fully four-coordinated aluminum species. More importantly, methanol-to-propylene tests show that the SPP zeolite nanosheets exhibit much higher propylene selectivity and longer reaction lifetime than conventional ZSM-5 zeolite. These results offer a good opportunity to develop highly efficient zeolite catalysts in the future.
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Novel all-hydrocarbon cross-linked aza-stapled peptides were designed and synthesized for the first time by ring-closing metathesis between two aza-alkenylglycine residues. Three aza-stapled peptidic analogues based on the peptide dual inhibitor of p53-MDM2/MDMX interactions were synthesized and screened for biological activities. Among the three aza-stapled peptides, aSPDI-411 displayed increased anti-tumor activity, binding affinities to both MDM2 and MDMX, and cell membrane permeability compared to its linear peptide counterpart.
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Proteínas Proto-Oncogénicas c-mdm2 , Proteína p53 Supresora de Tumor , Proteína p53 Supresora de Tumor/química , Secuencia de Aminoácidos , Péptidos/química , Unión Proteica , HidrocarburosRESUMEN
Recent studies revealed a causal relationship between Toll-like receptors (TLRs) and lipid droplet biogenesis. Interestingly, it has been reported before that nanomaterials (NMs) were capable to modulate TLRs, but it remains unclear if NMs could affect lipid levels via TLR signaling pathways. In this study, we investigated the influences of airway exposure to graphene oxide (GO) on TLR3 signaling pathways and lipid levels in mouse livers. Intratracheal instillation of GO (0.1, 1, and 5 mg/kg, once a day, totally 5 days) induced inflammatory cell infiltrations as indicated by hematoxylin-eosin (H&E) staining and fibrosis as indicated by Masson staining in lungs, accompanying with decreased TLR3 proteins. Consistently, a TLR3-regulated anti-virus protein, namely interferon induced protein with tetratricopeptide repeats 1 (IFIT1), as well as two TLR3-regulated lipid proteins, namely radical S-adenosyl methionine domain containing 2 (RSAD2) and perilipin 2 (PLIN2), were decreased in lungs. The protein levels of interferon-ß in serum were also decreased. In livers, GO exposure induced disorganization of liver cells but not fibrosis. In agreement with the trends observed in lungs, TLR3, IFIT1, RSAD2, and PLIN2 proteins were decreased in livers. As a possible consequence, GO exposure dose-dependently decreased lipid levels in livers as indicated by oil red O and BODIPY 493/503 staining. We concluded that airway exposure to GO decreased anti-virus responses and lipid levels in mouse livers via the suppression of TLR3.
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Receptor Toll-Like 3 , Receptores Toll-Like , Animales , Eosina Amarillenta-(YS) , Grafito , Hematoxilina , Interferón beta/metabolismo , Interferones/metabolismo , Lípidos , Hígado/metabolismo , Metionina , Ratones , Perilipina-2 , Receptor Toll-Like 3/metabolismo , Receptores Toll-Like/metabolismoRESUMEN
A simple dual-read assay for uric acid (UA) was developed based on a combined ratiometric fluorescent and colorimetric strategy using nitrogen-doped carbon dots (N-CDs). The biosensor relies on the oxidation of UA by uricase to produce H2O2, which was then converted to â¢OH radicals by I-, resulting in the oxidation of o-phenylenediamine (OPD) to 2,3-diaminophenazine (DAP). In the presence of UA, the colorless biosensor system changed to yellow. Furthermore, the presence of DAP quenched the fluorescence emission of the N-CDs at 427 nm based on the inner filter effect (IFE). With increasing UA concentrations, the fluorescence intensity of the biosensor at 427 nm decreased but increased at 580 nm, demonstrating the ratiometric response. A strong linearity was observed between the fluorescence intensity ratio of DAP to N-CDs (I580/I427) and the corresponding UA concentration over the range 0.5-150 µM, and a limit of detection (S/N ratio of 3) of 0.06 µM was calculated. The dual-read assay was successfully employed in the quantitation of UA in human serum and urine samples, revealing its potential for measuring UA in clinical samples.
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Colorimetría/métodos , Colorantes Fluorescentes/química , Puntos Cuánticos/química , Espectrometría de Fluorescencia/métodos , Ácido Úrico/sangre , Ácido Úrico/orina , Técnicas Biosensibles/métodos , Carbono/química , Humanos , Peróxido de Hidrógeno/química , Límite de Detección , Nitrógeno/química , Fenilendiaminas/química , Urato Oxidasa/química , Ácido Úrico/químicaRESUMEN
Carbonium ions are an important class of reaction intermediates, but their dynamic evolution is difficult to be monitored by in situ techniques under experimental conditions because of their extremely short lifetime. Probably the most famous case is 2-norbornyl cation (2NB+ ): its existing form (classical or non-classical) had been debated for decades, until the concrete proof of non-classical geometry was achieved by X-ray crystallographic characterization at ultra-low temperature (40â K) and super acidic environment. However, we lack the understanding about 2NB+ at ambient conditions. Herein, by taking advantage of the confinement effect and delocalized acidic environment of zeolites, we successfully stabilized 2NB+ and unequivocally confirmed its "non-classical" structure inside the ZSM-5 zeolite by ab initio molecular dynamics simulations and 13 C solid-state nuclear magnetic resonance experiments. It is the first time to in situ observe the non-classical 2NB+ without the super acidic environment at ambient temperature, which provides a new strategy to expand the carbocation chemistry.
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Soft materials that contain dynamic and reversible bonds exhibit unique properties including unusual extensibility, reversible elasticity, and self-healing capabilities, for example. Catechol motifs are of particular interest owing to their ability to form many kinds of reversible bonds; however, there are few reports on the role of hydrogen bonds between catechols. Here, physically crosslinked self-assembled networks composed of catechol-functionalized ABA triblock co-polymers are synthesized and characterized to elucidate the role of intermolecular bonding between catechol motifs on bulk mechanical properties. The Young's moduli of equilibrated networks range from 16 to 43 MPa. Furthermore, the concentration of intermolecular interaction is controlled indirectly by synthesizing polymers with prescribed catechol concentrations on each A block. Further, network dynamics are characterized by measuring the relaxation spectrum, and it is found that the network mean relaxation time is inversely related to catechol density. Finally, networks exhibit time-dependent recovery after uniaxial strain. These findings establish important relationships between molecular design, network composition, and macroscopic mechanical properties of model soft matter networks with dynamic intermolecular bonds. Furthermore, this insight has the potential to guide the design of dissipative materials for use in applications ranging from consumer products to surgical materials.
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Catecoles/química , Polietilenglicoles/química , Polímeros/química , Módulo de Elasticidad , Elasticidad , Enlace de Hidrógeno , Metacrilatos/química , Modelos Moleculares , Polímeros/síntesis químicaRESUMEN
BACKGROUND: Yes-associated protein (YAP) plays a crucial role in tumour development and it is the main effector of the Hippo signalling pathway. However, the mechanism underlying YAP downregulation in laryngeal cancer is still unclear. In our previous study, we found that YAP, compared with adjacent tissues, was expressed higher in laryngeal cancer and was also closely associated with histological differentiation, TNM stage and poor prognosis. METHODS: In this study, we attempted to determine whether silenced YAP could downregulate human laryngeal carcinoma Hep-2 cells progression. YAP was downregulated in Hep-2 cells by shRNA, and the malignant ability of Hep-2 was assessed in vitro and in vivo. RESULTS: In vitro, CCK-8, colony formation and wound healing assays showed that downregulation of YAP significantly reduced the rates of proliferation, migration, and invasion in Hep-2 cells. Downregulation of YAP distinctly induced G2/M cycle arrest and increased the rate of apoptosis. Accordingly, western blot assay suggested that the expression of DKK1, vimentin and ß-catenin was significantly decreased after YAP downregulated treatment, thereby indicating that YAP mediated the EMT programme and the Wnt/ß-catenin signalling pathway in carcinoma of the larynx. Furthermore, silencing of YAP suppressed Hep-2 cell tumourigenesis and metastasis in vivo. CONCLUSION: In summary, our findings demonstrated the proliferation of YAP downregulation and the invasion of Hep-2 cells via downregulating the Wnt/ß-catenin pathway in vitro and in vivo, suggesting that YAP may provide a potential therapeutic strategy for the treatment of laryngeal cancer.
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Proteínas Adaptadoras Transductoras de Señales/metabolismo , Neoplasias Laríngeas/metabolismo , Neoplasias Laríngeas/patología , Fosfoproteínas/metabolismo , beta Catenina/metabolismo , Animales , Apoptosis , Movimiento Celular , Proliferación Celular , Regulación hacia Abajo , Puntos de Control de la Fase G2 del Ciclo Celular , Técnicas de Silenciamiento del Gen , Puntos de Control de la Fase M del Ciclo Celular , Masculino , Ratones , Ratones Endogámicos BALB C , Invasividad Neoplásica , Estadificación de Neoplasias , ARN Interferente Pequeño , Sincalida , Factores de Transcripción , Ensayo de Tumor de Célula Madre , Vimentina/metabolismo , Vía de Señalización Wnt , Cicatrización de Heridas , Proteínas Señalizadoras YAPRESUMEN
A simple, rapid, and effective colorimetric assay for the detection of uric acid (UA) has been built, using the MoS2 nanoflakes-catalyzed 3,3',5,5'-tetramethylbenzidine (TMB)-H2O2 system. In the presence of oxygen and uricase, uric acid was oxidized specifically to produce H2O2. MoS2 nanoflakes synthesized by hydrothermal reaction could catalyze the oxidation of TMB by H2O2, and engendering the colorimetric signal. Finally, the change in the color from colorless to blue was seen with naked eye, indicating the presence or absence of UA. Under the optimized conditions, a linear relationship between the absorbance and UA concentration in the range of 0.5-100 µM (R2 = 0.996) with the limit of detection for 0.3 µM (S/N = 3). The proposed assay was successfully applied to the detection of UA in human serum with the recoveries over 94.54%. Thus, these results suggest that the UA assay-based MoS2-catalyzed TMB-H2O2 has great foreground for fast clinical diagnosis of gout without the need for advanced and costly equipment. Graphical Abstract á .
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Bencidinas/química , Colorimetría/métodos , Disulfuros/química , Molibdeno/química , Ácido Úrico/sangre , Catálisis , Color , Humanos , Peróxido de Hidrógeno/química , Radical Hidroxilo/química , Límite de Detección , Microscopía de Fuerza Atómica , Microscopía Electrónica de Transmisión , Estructura Molecular , Nanoestructuras/química , Oxidación-Reducción , Reproducibilidad de los Resultados , Espectrofotometría Ultravioleta , Difracción de Rayos XRESUMEN
A luminescent microRNA nanoprobe based on the target-triggered Ir(III)-solvent complex release has been fabricated. The complex is initially embedded into mesoporous silica nanoparticles (MSNs), and then is capped by single-stranded (ss) DNA. In the presence of the target microRNA, the ssDNA hybridize with the microRNA forming a rigid DNA/RNA heteroduplexes and leaving the surface of MSN. Thus, the capped Ir(III) solvent complex is released and re-coordinated with histidine (His) to form a new luminescent complex. The luminescence intensity of the nascent complex (with excitation/emission maxima at 340/570 nm) is positively correlated with the concentrations of the target microRNA in the range from 0.05 to 2 nM, and the detection limit of microRNA is estimated as 0.2 pM (S/N = 3). The ability of this nanoprobe to detect microRNA in cell extract further demonstrates its potential in practical application. Graphical abstractSchematic of a luminescent microRNA nanoprobe based on the target-triggered release of an Ir(III)-solvent complex from mesoporous silica nanoparticles.
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Complejos de Coordinación/química , Sustancias Luminiscentes/química , MicroARNs/química , Nanopartículas/química , Dióxido de Silicio/química , Acetonitrilos/química , ADN de Cadena Simple/química , ADN de Cadena Simple/genética , Histidina/química , Humanos , Iridio/química , Límite de Detección , Mediciones Luminiscentes/métodos , Células MCF-7 , MicroARNs/genética , Hibridación de Ácido Nucleico , Porosidad , Prueba de Estudio ConceptualRESUMEN
An HPLC method for combined quantification of five major constituents (vicenin-1, schaftoside, isoschaftoside, vicenin-3 and isovitexin) of Desmodium styracifolium was developed to evaluate the quality consistency of this medicinal herb. The chromatographic separation was accomplished on an Agilent 5 TC-C18 column (4.6 × 250 mm, 5 µm) with gradient elution using acetonitrile and 0.1 % aqueous formic acid (v/v). The column temperature was 30 °C and the detection wavelength was 272 nm. The chromatographic data were analyzed with a novel systematic quantitative fingerprint method (SQFM). The established quantitative fingerprint method was successfully applied to simultaneously determine the levels of the major constituents, and 39 common peaks were found. The samples collected in Guangdong province had a good quality consistency, in accordance with the traditional opinion that Guangdong province is the best region for cultivation of D. styracifolium. The fingerprint-antioxidant efficacy relationship of the different samples was investigated by examining the correlation between the common peaks and the antioxidant effect. Twenty-two common peaks were positively correlated with the antioxidant effect, while the others showed a negative correlation. This quantitative fingerprint method could be considered as a suitable approach to evaluate the quality of traditional Chinese medicines and herbal preparations. The SQFM was reliable and efficient for analysis of the chromatographic data.
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Cromatografía Líquida de Alta Presión/métodos , Fabaceae/química , Extractos Vegetales/análisis , Acetonitrilos/química , Antioxidantes/análisis , Apigenina/análisis , Medicamentos Herbarios Chinos/análisis , Glucósidos/análisis , Glicósidos/análisisRESUMEN
HPLC analysis was performed on a Phenomenex PS C18ï¼4.6 mm×250 mm, 5 µmï¼column using methanol -0.2% formic acid (30:70) at a flow rate of 0.8 mL·min⻹. The column temperature was 30 °C and the detection wavelength was set at 335 nm. The injection volume was 10 µL. The HPLC fingerprint of Desmodium styracifolium was established with 10 common peaks, and 5 of them were identified as vicenin-1, schaftoside, isoorientin, isoschaftoside and isovitexin, respecivetly. The fingerprints of 21 batches of D. styracifolium samples were analyzed with similarity evaluation, cluster analysis, principal component analysis and partial least squares discriminant analysis. There was no significant difference among the quantitative results of these five ingredients verified by external standard method (ESM) and quantitative analysis of multi-components by single marker (QAMS) method. The application of fingerprint, pattern recognition combined with QAMS can provide more comprehensive references for the quality control and evaluation of D. styracifolium.
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Medicamentos Herbarios Chinos/normas , Fabaceae/química , Control de Calidad , Cromatografía Líquida de Alta Presión , Medicamentos Herbarios Chinos/química , Fitoquímicos/análisisRESUMEN
Crossovers (COs) shuffle genetic information and allow balanced segregation of homologous chromosomes during the first division of meiosis. In several organisms, mutants demonstrate that two molecularly distinct pathways produce COs. One pathway produces class I COs that exhibit interference (lowered probability of nearby COs), and the other pathway produces class II COs with little or no interference. However, the relative contributions, genomic distributions, and interactions of these two pathways are essentially unknown in nonmutant organisms because marker segregation only indicates that a CO has occurred, not its class type. Here, we combine the efficiency of light microscopy for revealing cellular functions using fluorescent probes with the high resolution of electron microscopy to localize and characterize COs in the same sample of meiotic pachytene chromosomes from wild-type tomato. To our knowledge, for the first time, every CO along each chromosome can be identified by class to unveil specific characteristics of each pathway. We find that class I and II COs have different recombination profiles along chromosomes. In particular, class II COs, which represent about 18% of all COs, exhibit no interference and are disproportionately represented in pericentric heterochromatin, a feature potentially exploitable in plant breeding. Finally, our results demonstrate that the two pathways are not independent because there is interference between class I and II COs.