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Herein, a novel tetrahedral DNA walker with four arms was engineered to travel efficiently on the 3D-tracks via catalyzed hairpin assembly autonomously, realizing the sensitive detection and activity assessment as well as intracellular imaging of apurinic/apyrimidinic endonuclease 1 (APE1). In contrast to traditional DNA walkers, the tetrahedral DNA walker with the rigid 3D framework structure and nonplanar multi-sites walking arms endowed with high collision efficiency, showing a fast walking rate and high nuclease resistance. Impressively, the initial rate of the tetrahedral DNA walker with four arms was 4.54 times faster than that of the free bipedal DNA walker and produced a significant fluorescence recovery in about 40 min, achieving a sensitive detection of APE1 with a low detection limit of 5.54× 10-6 U/µL as well as ultrasensitive intracellular APE1 fluorescence activation imaging. This strategy provides a novel DNA walker for accurate identification of low-abundance cancer biomarker and potential medical diagnosis.
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DNA Liase (Sítios Apurínicos ou Apirimidínicos) , DNA , DNA/química , Reparo do DNA , DNA Liase (Sítios Apurínicos ou Apirimidínicos)/metabolismo , Endonucleases , FluorescênciaRESUMO
Herein, Ag@pyrenecarboxaldehyde nanocapsules (Ag@Pyc nanocapsules) as emitters were prepared to construct an ultrasensitive electrochemiluminescence (ECL) biosensor for the detection of the human apurinic/apyrimidinic endonuclease1 (APE1) activity. Ag nanoparticles on the surface of Pyc nanocapsules as coreaction accelerators could significantly promote coreactant peroxydisulfate (S2O82-) to generate massive reactive intermediates of sulfate radical anion (SO4â¢-), which interacted with the Pyc nanocapsules to achieve a strong ECL response. In addition, with the aid of APE1-triggered 3D DNA machine, trace target could be converted into a large number of mimic targets (MTs), which were positively correlated with the activity of APE1. Consequently, the proposed ECL biosensor realized an ultrasensitive detection of APE1 activity with an exceptional linear working range from 5 × 10-10 to 5 × 10-4 U·µL-1 and a lower limit of detection of 1.36 × 10-11 U·µL-1. This strategy provided a new approach to construct an efficient ternary system for the detection of biomolecules and early diagnosis of diseases.
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Técnicas Biossensoriais , Nanopartículas Metálicas , Nanocápsulas , Técnicas Eletroquímicas , Humanos , Limite de Detecção , Medições Luminescentes , PrataRESUMO
Functional nucleic acids(FNAs) refer to a type of oligonucleotides with functions over the traditional genetic roles of nucleic acids, which have been widely applied in screening, sensing and imaging fields. However, the potential application of FNAs in biomedical field is still restricted by the unsatisfactory stability, biocompatibility, biodistribution and immunity of natural nucleic acids(DNA/RNA). Xeno nucleic acids(XNAs) are a kind of nucleic acid analogues with chemically modified sugar groups that possess improved biological properties, including improved biological stability, increased binding affinity, reduced immune responses, and enhanced cell penetration or tissue specificity. In the last two decades, scientists have made great progress in the research of functional xeno nucleic acids, which makes it an emerging attractive biomedical application material. In this review, we summarized the design of functional xeno nucleic acids and their applications in the biomedical field.
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Objective: To study with quantitative computed tomography (QCT) the correlation between grip strength and physical composition and waist and hip circumferences in young people with different body mass indexes (BMIs). Methods: A total of 1310 young people who came to West China Hospital, Sichuan University for physical checkups and underwent chest QCT at our hospital from April to July 2021 were included in the study. Their data were collected and their BMIs were calculated. The subjects were divided according to their BMIs into 4 groups, underweight group (BMI<18.5 kg/m 2), normal-weight group (18.5 kg/m 2≤BMI<24 kg/m 2), overweight group (24 kg/m 2≤BMI<28 kg/m 2), and obesity group (BMI≥28 kg/m 2). The raw data were uploaded to QCT Mindways Pro 6.1 software to be processed for measurement of the fat content (area) of the physical components of the L2 vertebral body, including total adipose tissue (TAT), visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and abdominal fat ratio, or VAT/SAT. Grip strength was measured with CAMRY EH101 digital grip dynamometer. Statistical analysis of the data was performed, and the correlations between grip strength and various physical components, waist circumference, and hip circumference in subjects of different BMIs were examined. In addition, stratified analysis of normal-weight and overweight subjects of different age groups was conducted. Results: In the normal-weight group, height, body mass, hip circumference and grip strength were positively correlated with grip strength in males aged 21-40 years, SAT was negatively correlated with grip strength in males aged 36-40 years, and VAT/SAT was positively correlated with grip strength in males aged 36-40 years. In normal-weight females aged 21-25 years, SAT was negatively correlated with grip strength, while VAT and VAT/SAT were positively correlated with grip strength. In normal-weight females aged 26-40 years, height, body mass, and hip circumference were positively correlated with grip strength. In normal-weight females aged 36-40 years, VAT/SAT was positively correlated with grip strength. In overweight males aged 21-25 years, hip circumference and body mass were positively correlated with grip strength. In overweight males aged 26-30 years, TAT, waist-to-hip ratio, and waist-to-height ratio were negatively correlated with grip strength. In overweight males aged 31-40 years, height and body mass were positively correlated with grip strength, while waist-to-hip ratio and waist-to-height ratio were negatively correlated with grip strength. In addition, hip circumference was positively correlated with grip strength in overweight males aged 31-35 years. In overweight females aged 21-25 years, waist circumference, hip circumference, and waist-to-height ratio were positively correlated with grip strength. In overweight females aged 26-30 years, height and body mass were positively correlated with grip strength. In overweight females aged 31-35 years, TAT, SAT, waist circumference, waist-to-hip ratio, and waist-to-height ratio were negatively correlated with grip strength. In overweight females aged 36-40 years, SAT and waist-to-height ratio were negatively correlated with grip strength, while VAT, VAT/SAT, height and body mass were positively correlated with grip strength. The height and body mass of males and females in the underweight group were positively correlated with grip strength, and the hip circumference of females in the underweight group was also positively correlated with grip strength. In the obesity group, TAT, VAT, and waist-to-height ratio were negatively correlated with grip strength in males, but no such correlation was observed in females. Conclusion: There is a close association between abdominal fat content and grip strength in young people with different BMIs, indicating that young people should control abdominal fat content and hip fat content in order to maintain the strength of corresponding muscles.
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Sobrepeso , Magreza , Feminino , Masculino , Humanos , Adolescente , Força da Mão , Tomografia Computadorizada por Raios X , ObesidadeRESUMO
Activation of invasion and metastasis is recognized as one of the hallmarks of cancer. There are 90% of cancer-related deaths due to metastasis and given that it is worthy of note to study cancer progression and metastasis. Owing to restricted tools used to underpin the study of tumor invasion process, an on-site platform was developed to monitor this event in vitro. We used interdigital gold electrodes to monitor the dynamic process of cancer cells invading into extracellular matrix in situ continuously. Influences of collagen concentration and number of cancer cells on the measured impedance was exhibited. In addition, the parameters used to demonstrate the experiment results were optimized. The change of impedance magnitude indicated the cell-matrix interaction during invasion process. The potential further use of this platform would be complementary in cell studies when concerning metastasis.
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Adenocarcinoma/patologia , Técnicas Biossensoriais/métodos , Espectroscopia Dielétrica/métodos , Neoplasias Hepáticas/patologia , Invasividade Neoplásica/patologia , Adenocarcinoma/metabolismo , Linhagem Celular Tumoral , Impedância Elétrica , Eletrodos , Matriz Extracelular/metabolismo , Ouro/química , Humanos , Neoplasias Hepáticas/metabolismo , Metástase Neoplásica/patologiaRESUMO
There is a great demand for robust diagnostic and prognostic approaches for Hepatocellular Carcinoma (HCC). DNA methylation, a common epigenetic modification, has been found in many promoter regions of tumor suppressor genes. Hypermethylation of these gene promoters will repress the gene transcription and lead to the occurrence of cancers. The abnormal methyation level of the p16 gene promoter could be a promising marker for the detection of HCC. The adsorption affinities between different DNA bases and AuNPs are not the same. After bisulfite treatment and asymmetric PCR, methylation and unmethylation sequences can be changed into guanine-enriched and adenine-enriched sequences, respectively. A home-made gold nanoparticle modified screen printed carbon electrode (AuNP-SPCE) was employed to distinguish the adsorption affinities between guanine-enriched and adenine-enriched sequences, which could be used to analyze the level of DNA methylation. Several key experimental factors were investigated and optimized. The results had shown that the optimal AuNP electrodeposition time was 100 s and 15 min of adsorption could distinguish guanine-enriched and adenine-enriched sequences with a concentration of 100 nM at 25 °C. The detection limit of our AuNP-SPCE was 1.1 ng, and the assay had a good sensitivity of 10% methylation change and was able to distinguish only one methylated CpG site. What's more, the RSD over three assays with a disposable AuNP-SPCE was ≤7.2%. The assay was applied to real samples including cell lines and clinical tissues. Compared with normal hepatic cell lines and normal tissues, lower signals of HCC cell lines and cancer tissues were observed, respectively. It had shown a good discrimination of the abnormal methylation level of the p16 gene promoter.
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Carcinoma Hepatocelular/genética , Metilação de DNA , DNA/análise , DNA/genética , Eletrodos , Neoplasias Hepáticas/genética , Adenina/química , Adsorção , Carbono/química , Linhagem Celular Tumoral , DNA/química , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Genes p16 , Ouro/química , Guanina/química , Humanos , Limite de Detecção , Nanopartículas Metálicas/química , Regiões Promotoras GenéticasRESUMO
In this study, polysaccharides (RRTPs) were extracted from Rosa roxburghii Tratt pomace by hot water or ultrasound (US)-assisted extraction. The structural properties and potential prebiotic functions of RRTPs were investigated. Structural characterization was conducted through HPAEC, HPGPC, GC-MS, FT-IR and SEM. Chemical composition analysis revealed that RRTPs extracted by hot water (RRTP-HW) or US with shorter (RRTP-US-S) or longer duration (RRTP-US-L) all consisted of galacturonic acid, galactose, glucose, arabinose, rhamnose and glucuronic acid in various molar ratio. US extraction caused notable reduction in molecular weight of RRTPs but no significant changes in primary structures. Fecal fermentation showed RRTPs could reshape microbial composition toward a healthier balance, leading to a higher production of beneficial metabolites including total short-chain fatty acids, curcumin, noopept, spermidine, 3-feruloylquinic acid and citrulline. More beneficial shifts in bacterial population were observed in RRTP-HW group, while RRTP-US-S had stronger ability to stimulate bacterial short-chain fatty acids production. Additionally, metabolic profiles with the intervention of RRTP-HW, RRTP-US-S or RRTP-US-L were significantly different from each other. The results suggested RRTPs had potential prebiotic effects which could be modified by power US via molecular weight degradation.
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Polissacarídeos , Prebióticos , Rosa , Rosa/química , Polissacarídeos/química , Polissacarídeos/isolamento & purificação , Peso Molecular , Ondas Ultrassônicas , Fermentação , Fracionamento Químico/métodosRESUMO
Chitosan is a natural polysaccharide that is abundant, biocompatible and exhibits effective antifungal activity against various pathogenic fungi. However, the potential intracellular targets of chitosan in pathogenic fungi and the way of activity of chitosan are far from well known. The present work demonstrated that chitosan could inhibit Penicillium expansum, the principal causal agent of postharvest blue mold decay on apple fruits, by binding to DNA and triggering apoptosis. UV-visible spectroscopy, fluorescence spectroscopy and electrophoretic mobility assay proved the interaction between chitosan and DNA, while atomic force microscope (AFM) observation revealed the binding morphology of chitosan to DNA. Chitosan could inhibit in vitro DNA replication, and cell cycle analysis employing flow cytometry demonstrated that cell cycle was retarded by chitosan treatment. Furthermore, the reactive oxygen species (ROS) assay and membrane potential analysis showed that apoptosis was induced in P. expansum cells after exposure to chitosan. In conclusion, our results confirmed that chitosan interacts with DNA and induces apoptosis. These findings are expected to provide a feasible theoretical basis and practical direction for the promoting and implementing of chitosan in plant protection and further illuminate the possible antifungal mechanisms of chitosan against fungal pathogens.
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Quitosana , Malus , Penicillium , Antifúngicos/farmacologia , Quitosana/farmacologia , Penicillium/genética , Frutas , DNA/farmacologiaRESUMO
Aspergillus westerdijkiae can infect many agricultural products including cereals, grapes, and pear. Pathogenic fungi secrete diverse effectors as invasive weapons for successful invasion the host plant. During the pathogen-host interaction, 4486 differentially expressed genes were observed in A. westerdijkiae with 2773 up-regulated and 1713 down-regulated, whereas 8456 differentially expressed genes were detected in pear fruits with 4777 up-regulated and 3679 down-regulated. A total of 309 effector candidate genes were identified from the up-regulated genes in A. westerdijkiae. Endoglucanase H (AwEGH) was significantly induced during the pathogen-host interaction. Deletion of AwEGH resulted in altered fungal growth and morphology and reduced conidia production and germination compared to the wild-type. Further experiments demonstrated that AwEGH plays a role in cell wall integrity. Importantly, disruption of AwEGH significantly reduced the fungal virulence on pear fruits, and this defect can be partly explained by the impaired ability of A. westerdijkiae to penetrate host plants.
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Aspergillus , Celulase , Pyrus , Pyrus/genética , Celulase/genética , Virulência , Frutas/genética , Proteínas Fúngicas/genéticaRESUMO
Purpose: We aim to observe the potential survival benefits of driver gene-guided targeted therapy in advanced non-small cell lung cancer (NSCLC) patients compared to non-targeted therapy. Additionally, the study aims to assess whether Next-generation sequencing technology (NGS)-guided targeted therapy can provide survival advantages for advanced NSCLC patients compared to conventional Epidermal growth factor receptor (EGFR)/anaplastic lymphoma kinase (ALK) gene detection. Methods: Clinical data, genetic testing results, and treatment information of 1663 advanced lung cancer patients diagnosed by pathology from January 2013 to June 2019 in Jiangsu University Affiliated Lianyungang Hospital were collected. Propensity score matching survival analysis was used to evaluate the differences in overall survival(OS) between groups. Results: In the unadjusted survival curve, targeted therapy patients had significantly longer median OS than non-targeted therapy patients (28.3 months vs 15.4 months, Hazard ratio (HR) = 0.5426, 95% confidence interval (CI) 0.4768-0.6176, P < 0.0001); the conclusion was the same after propensity score matching analysis, with targeted therapy group patients having significantly prolonged OS median (27.5 months vs 14.8 months, HR = 0.5572, 95% CI 0.4796-0.6474, P < 0.0001). In the unadjusted survival curve, the NGS group had a significantly prolonged median OS compared to the conventional gene detection group (23.4 months vs 21.2 months, HR = 1.243, 95% CI = 1.017-1.519, P = 0.0495). However, after propensity score matching analysis, no statistically significant difference existed in the median OS between the two patient groups (23.1 months vs 21.5 months, HR = 1.288, 95% CI = 0.9557-1.735, P = 0.0926). Further analysis demonstrated no advantage in the five-, three-, and two-year survival rates of the NGS group compared to conventional gene detection group patients. However, the one-year survival rate of the NGS group was significantly increased (83.2% vs 68.1%, HR = 0.4890, 95% CI = 0.3170-0.7544, P = 0.0015). Conclusion: Driver gene-guided targeted precision therapy significantly prolonged the median OS of advanced NSCLC patients compared to non-targeted therapy. NGS detection did not improve the median OS of advanced NSCLC patients compared to conventional EGFR/ALK gene detection but increased the one-year survival rate of patients.
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Penicillium expansum is the causal agent of blue mold decay on apple fruits and is also known to be the major producer of patulin, a mycotoxin that represents serious hazard to human health. Several mechanisms have been suggested to explain the pathogenesis of P. expansum in host plants. Secreted effector proteins are vital for the pathogenicity of many fungal pathogens through manipulating their hosts for efficient colonization. In this study, we performed a RNA-Seq analysis followed by computational prediction of effector proteins from P. expansum during infection of the host apple fruits, and a total of 212 and 268 candidate effector protein genes were identified at 6 and 9 h after inoculation (hai), respectively. One of the candidate effector protein genes was identified as a concanavalin A-like lectin/glucanase (Peclg), which was dramatically induced during the pathogen-host interaction. Targeted knockout of Peclg resulted in significant reduction in conidial production and germination relative to the wild type. Further studies showed that in addition to salt stress, the mutant was much more sensitive to SDS and Congo red, suggesting a defect in cell wall integrity. Pathogenicity assays revealed that the ΔPeclg mutant showed significant decrease in virulence and infectious growth on apple fruits. All these results suggest that Peclg is required for fungal growth, stress response, and the virulence of P. expansum.
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BACKGROUND: There were controversies for the association between computed tomography (CT)-determined low skeletal muscle mass (SMM) and overall survival (OS) in gastric cancer (GC). In this study, we investigated whether cachexia could be a potential confounding variable for this issue. METHODS: We retrospectively collected the patients of GC in our institution between July 2016 and January 2021. Preoperative SMM was determined by analyzing the skeletal muscle index of L3 with abdominal CT, and the cut-offs for low SMM were defined as <52.4 (men) and < 38.5 cm2 /m2 (women), respectively. Overall survival (OS) was the primary endpoint. RESULTS: Of the 255 included GC patients, 117 (46%) were classified as having low SMM. Those with low SMM were associated with a higher level of circulating interleukin 6 and C reactive protein but a lower level of albumin than those of normal SMM. The univariate analysis showed that low SMM, tumor-node-metastasis (TNM) stage, body mass index (BMI), postoperative chemotherapy, and cachexia were significantly associated with OS, while in the multivariate analysis, only low SMM and TNM stage were significantly associated with OS. Kaplan-Meier survival curves with log-rank tests indicated that low SMM significantly predicted worse OS of GC. After grouping by cachexia, the low SMM significantly predicted worse OS in patients with cachexia instead of those without cachexia. CONCLUSIONS: CT-determined low SMM predicts worse OS of GC in patients with cachexia instead of those without cachexia, and greater attention should be paid to such patients with synchronous low SMM and cachexia.
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Caquexia , Neoplasias Gástricas , Masculino , Humanos , Feminino , Prognóstico , Estudos Retrospectivos , Caquexia/etiologia , Caquexia/patologia , Neoplasias Gástricas/patologia , Músculo Esquelético/diagnóstico por imagem , Músculo Esquelético/patologia , Tomografia Computadorizada por Raios XRESUMO
Carbon nanotube fibers (CNTFs) are widely utilized in flexible and wearable electronics due to their outstanding electrical and mechanical properties. However, the spinning process of CNTFs has limited the CNTs from exposure, leading to an ultralow usage efficiency of individual CNTs. Here, we propose an electrochemical expansion strategy of a single CNTF at the liquid-air interface, forming a macroscopic spindle-shaped CNTF (SS-CNTF) with an enlarged volume of up to 5000-fold upon the spindle. The obtained spindle-shaped structure endows CNTF with a high specific surface area together with excellent conductivity and good mechanical properties. Therefore, the SS-CNTF-based devices exhibit outstanding performances both in energy storage (electrical double-layer supercapacitor, energy density: 11.22 Wh kg-1, power density: 203.9 kW kg-1) and electrochemical sensing (ascorbic acid: 1.26 µA µM-1 cm-2; dopamine: 103.91 µA µM-1 cm-2; uric acid: 11.53 µA µM-1 cm-2). The novel architecture of SS-CNTF prepared by one-step electrochemical expansion at the liquid-air interface enabled its high performance in multiple applications, providing new insight into the development of CNTF-based devices.
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Urine analysis is widely used in clinical practice to indicate human heathy status and is important for diagnosing chronic kidney disease (CKD). Ammonium ions (NH4+), urea, and creatinine metabolites are main clinical indicators in urine analysis of CKD patients. In this paper, NH4+ selective electrodes were prepared using electropolymerized polyaniline-polystyrene sulfonate (PANI: PSS), and urea- and creatinine-sensing electrodes were prepared by modifying urease and creatinine deiminase, respectively. First, PANI: PSS was modified on the surface of an AuNPs-modified screen-printed electrode, as a NH4+-sensitive film. The experimental results showed that the detection range of the NH4+ selective electrode was 0.5~40 mM, and the sensitivity reached 192.6 mA M-1 cm-2 with good selectivity, consistency, and stability. Based on the NH4+-sensitive film, urease and creatinine deaminase were modified by enzyme immobilization technology to achieve urea and creatinine detection, respectively. Finally, we further integrated NH4+, urea, and creatinine electrodes into a paper-based device and tested real human urine samples. In summary, this multi-parameter urine testing device offers the potential for point-of-care testing of urine and benefits the efficient chronic kidney disease management.
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Técnicas Biossensoriais , Nanopartículas Metálicas , Insuficiência Renal Crônica , Humanos , Ouro , Creatinina , Urease , Eletrodos , Ureia/análise , Técnicas Biossensoriais/métodos , Compostos de AnilinaRESUMO
With the development of social media, advertising has migrated from traditional media to social media. Marketers are increasingly using social media's brand pages to actively create humorous dialogue interactions with other brands for brand communication to achieve positive business outcomes. Especially brand-to-brand's aggressive humor dialogue can also be an effective brand communication strategy. Based on benign violation theory, we have studied the influence mechanism and boundary condition of the brand-to-brand's aggressive humor styles (low-aggressive and high-aggressive) on consumer engagement behavioral intention in social media context. Through experiments, it is indicated that low-aggressive humor could promote consumer engagement behavioral intention more than high-aggressive humor. Benign appraisal mediates the relationship between low-aggressive humor and consumer engagement behavioral intention. Furthermore, brand personality not only moderates the effect of low-aggressive humor on consumer engagement behavioral intention, but also moderates the mediating role of benign appraisal between low-aggressive humor and consumer engagement behavior intention.
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International openness can affect regional innovation through more export opportunities, enhanced import competition and the spillover effects of foreign direct investment. Many studies have been conducted based on different countries for capturing the determinants of regional innovation, but very little literature is available with contradictory findings for the case of China. Based on 19 years' panel data of 31 Chinese provinces, this paper analyzes the impact of international openness on regional innovation measured by the number of patent grants. The positive effects of overall trade and a higher proportion of exports and imports to GDP are significant and robust across different model specifications, indicating that an increase in international openness can promote regional innovating activities in China. The causal relationship of all the variables depicted by path analysis matches the results of the system GMM model. Higher intellectual property protection provides each region with the opportunity to obtain economic benefits from innovation and then make a higher investment in R&D activities. Besides, the lag effect of regional innovation capability can also explain a large part of local innovating activities. In our subsample regressions, the positive effect of trade openness on innovation is majorly manifested in developed areas like eastern provinces.
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Desenvolvimento Econômico , Propriedade Intelectual , China , Humanos , Invenções , Investimentos em Saúde , PolíticaRESUMO
Recently, ternary electrochemiluminescence (ECL) system has become a hot research topic due to its great potential for improving ECL efficiency by promoting the generation of intermediates. However, it is still a great challenge to increase the utilization rate of intermediates in a ternary ECL system. Herein, we propose a strategy to increase the utilization rate of intermediates by designing pyrenecarboxaldehyde (Pyc) encapsulated porous titania (pTiO2) nanospheres (Pyc@pTiO2) as ECL nanoreactors for an integrated ternary (luminophore/coreactant/co-reaction accelerator, Pyc/S2O82-/TiO2) ECL system construction. Specifically, pTiO2 acted as an ECL co-reaction accelerator, in which Pyc could obtain electrons from the conduction band of TiO2 to produce more SO4Ë-, increasing its emissions. Simultaneously, pTiO2 could provide confined reaction spaces to effectively shorten the diffusion distance, extend the lifetime of free radicals, increase the utilization rate of intermediates and improve the efficiency of the ternary ECL system. As a proof of concept, the Pyc@pTiO2 nanoreactors-based sensing platform was successfully constructed to sensitively monitor cellular GSH levels. Overall, this work for the first time proposed an avenue to increase the utilization rate of intermediates in a ternary ECL system, which opened a new route for ECL biosensing in cell analysis applications.
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Técnicas Biossensoriais , Técnicas Eletroquímicas , Medições Luminescentes , Nanotecnologia , Porosidade , TitânioRESUMO
Endowed with a soft and conductive feature, hydrogels have been widely used as interface materials in bioelectronics to fulfill mechanical matching and bidirectional exchange between electronic platforms and living samples. Despite their ionic conductivity, the lack of electron mobility has limited their further applications in biosensing, especially in the field of electrochemical sensing. Here, we propose a Ti3C2/sodium alginate (SA) hybrid hydrogel with not only a tissue-like mechanical strength (down to 80 kPa) but also a combined exchange interface for ions and electrons, realizing both mechanical and electrical coupling toward biological tissues. Due to the shared gelation tendency with cations, the Ti3C2 sheets and SA chains can be easily in situ coassembled through a one-step electrogelation method, making the hybrid hydrogel a well-suited interface layer for device functionalization. In addition, the typical two-dimensional (2D) structure and the abundant active terminals of Ti3C2 have endowed the Ti3C2/SA with a massive loading capacity toward catalytic nanoparticles. For example, the Prussian Blue (PB)-loaded Ti3C2/SA hybrid hydrogel exhibited an excellent electrochemical performance (sensitivity: 600 nA µM-1 cm-2; LOD: 12 nM) toward hydrogen peroxide sensing in tissue fluids, illustrating a promising application potentiality of the hybrid hydrogel in biochemical detection at tissue interfaces.
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Alginatos , Hidrogéis , Hidrogéis/química , Alginatos/química , Titânio/química , Condutividade Elétrica , ÍonsRESUMO
MXene based composite conductive aerogels have been extensively investigated as sensitive materials for wearable pressure sensors owing to their effective 3D network microstructures and the excellent conductivity of MXene. In this work, we fabricated a 3D porous Ti3C2Tx MXene/poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) composite aerogel (MPCA) with a controllable patterning property utilizing the Cu-assisted electrogelation method. The prepared composite aerogel can be assembled into pressure sensors for wearable physical monitoring and high-resolution sensor microarrays for robotic tactile sensing. The multi-interactions between MXene and PEDOT:PSS enable the MPCA to have a stable 3D conductive network, which consequently enhances both the mechanical flexibility and the piezoresistive property of the MPCA. Thus, the fabricated pressure sensor demonstrating high sensitivity (26.65 kPa-1 within 0-2 kPa), fast response ability (106 ms), and excellent stability can be further applied for wearable physical monitoring. Moreover, due to the controllable patterning property of the electrogelation preparation method, a high-resolution pressure sensor microarray was successfully prepared as an artificial tactile interface, which can be attached to a robotic fingertip to directly recognize the tactile stimuli from human fingers and identify braille letters like human fingers. The proposed MPCA, endowed with a remarkable comprehensive property, particularly the highly sensitive sensing performance and controllable patterning property, demonstrates an enormous advantage and a great potentiality toward wearable electronics.
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Ochratoxin A (OTA), primarily produced by the fungi belonging to the species of Aspergillus and Penicillium, is one of the most common mycotoxins found in cereals and fruits. In addition to resulting in huge economic losses, OTA contamination also poses considerable threat to human and livestock health. Microbial degradation of mycotoxins has been considered with great potential in mycotoxins decontamination. In a previous study, Bacillus velezensis E2 was isolated by our laboratory and showed appreciable inhibitory effect on Aspergillus flavus growth and aflatoxin production in rice grains. In this study, B. velezensis E2 was investigated for its ability to remove OTA and biocontrol against the ochratoxigenic Aspergillus westerdijkiae fc-1. The results revealed that B. velezensis E2 has considerable inhibitory effect on A. westerdijkiae fc-1 both on PDA medium and pear fruits, with inhibitory rate of 51.7% and 73.9%, respectively. In addition, its ability to remove OTA was evaluated in liquid medium and the results showed that more than 96.1% of OTA with an initial concentration of 2.5 µg/mL could be removed by B. velezensis E2 in 48 h. Further experiments revealed that enzymatic transformation and alkaline hydrolysis might be the main mechanisms related to OTA degradation by B. velezensis E2, with ring open ochratoxin α (OP-OTα) as a possible degradation product. Our study indicated that the B. velezensis E2 strain could be a potential bacterial candidate in biodegradation of OTA and biocontrol against A. westerdijkiae fc-1.