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In both cancer and infections, diseased cells are presented to human Vγ9Vδ2 T cells through an 'inside out' signalling process whereby structurally diverse phosphoantigen (pAg) molecules are sensed by the intracellular domain of butyrophilin BTN3A11-4. Here we show how-in both humans and alpaca-multiple pAgs function as 'molecular glues' to promote heteromeric association between the intracellular domains of BTN3A1 and the structurally similar butyrophilin BTN2A1. X-ray crystallography studies visualized that engagement of BTN3A1 with pAgs forms a composite interface for direct binding to BTN2A1, with various pAg molecules each positioned at the centre of the interface and gluing the butyrophilins with distinct affinities. Our structural insights guided mutagenesis experiments that led to disruption of the intracellular BTN3A1-BTN2A1 association, abolishing pAg-mediated Vγ9Vδ2 T cell activation. Analyses using structure-based molecular-dynamics simulations, 19F-NMR investigations, chimeric receptor engineering and direct measurement of intercellular binding force revealed how pAg-mediated BTN2A1 association drives BTN3A1 intracellular fluctuations outwards in a thermodynamically favourable manner, thereby enabling BTN3A1 to push off from the BTN2A1 ectodomain to initiate T cell receptor-mediated γδ T cell activation. Practically, we harnessed the molecular-glue model for immunotherapeutics design, demonstrating chemical principles for developing both small-molecule activators and inhibitors of human γδ T cell function.
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Butirofilinas , Activación de Linfocitos , Fosfoproteínas , Receptores de Antígenos de Linfocitos T gamma-delta , Linfocitos T , Animales , Humanos , Antígenos CD/inmunología , Antígenos CD/metabolismo , Butirofilinas/inmunología , Butirofilinas/metabolismo , Camélidos del Nuevo Mundo/inmunología , Simulación de Dinámica Molecular , Fosfoproteínas/inmunología , Fosfoproteínas/metabolismo , Receptores de Antígenos de Linfocitos T gamma-delta/inmunología , Receptores de Antígenos de Linfocitos T gamma-delta/metabolismo , Linfocitos T/citología , Linfocitos T/inmunología , Linfocitos T/metabolismo , Cristalografía por Rayos X , Resonancia Magnética Nuclear Biomolecular , TermodinámicaRESUMEN
Urolithiasis stands as a prevalent ailment within the urinary system, with hyperoxaluria and hypocitraturia being the most frequent manifestations characterized by excessive oxalic acid (OA) and deficient citric acid (CA) levels in urine. Detecting these compounds in urine quantitatively holds paramount importance for early urolithiasis screening. Existing methodologies fall short in achieving simultaneous and on-site identification of OA and CA, posing challenges for accurate urolithiasis screening. Addressing this concern, the study successfully accomplishes the concurrent identification of OA and CA in urine through a combination of dual-spectral analysis and biomimetic peroxidase utilization. Bovine serum albumin and dithiothreitol-modified copper nanoclusters (BSA-DTT-CuNCs) are employed as biomimetic peroxidases, effectively mitigating interference and enabling the simultaneous determination of OA and CA. The quantification range spans from 0 to 12 mm for OA and 0.5 to 2.5 mm for CA, with detection limits of 0.18 and 0.11 mm, respectively. To facilitate swift and on-location urine analysis, a fully automated urine analyzer (FAUA) is introduced that streamlines the process of biomarker pretreatment and identification within urine samples. Validation with real urine samples from urolithiasis patients demonstrates the method's diagnostic precision, highlighting the dual-spectral technique and analyzer's promising role in urolithiasis screening.
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Peroxidasa , Urolitiasis , Humanos , Ácido Oxálico , Biomimética , Peroxidasas , Urolitiasis/diagnóstico , Ácido Cítrico , ColorantesRESUMEN
Regioselective methods to access alkylated tetrazoles still remain a challenging goal. Herein, we describe a novel regioselective protocol for N2-arylation of tetrazoles with diazo compounds using inexpensive Al(OTf)3. This reaction could be conducted under mild conditions to access a diverse array of alkylated tetrazoles with 2-substituted tetrazoles as the major products, demonstrating a comprehensive range of substrate compatibility and excellent functional group compatibility. Mechanistic studies revealed a carbene-free process in this reaction procedure. Furthermore, the scale-up reaction and transformations of the N2-arylation of tetrazole products demonstrated the potential of this strategy.
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Studies of how positive and negative coping styles affect social anxiety show mixed results. Hence, our two meta-analyses determined the overall effect sizes of problem solving-focused coping (PSC) styles and emotion-focused coping (EFC) styles on social anxiety in mainland China (PSC: k = 49 studies, N = 34,669; EFC: k = 52, N = 36,531). PSC was negatively linked to social anxiety (- .198), and EFC was positively linked to social anxiety (.223). In years with more national income, PSC's and EFC's effect sizes were larger. PSC's effect sizes were smaller among rural students (vs. urban students), larger among older students (university, high school, middle school), and larger in cross-sectional (vs. longitudinal) studies. When using SAD (vs. others) social anxiety measures, PSC effect sizes were larger, but EFC effect sizes were smaller. EFC effect sizes were larger in studies with convenience (vs. representative) samples. Gender, single child status, and coping style measurement showed no moderation effects. These findings suggest that using problem solving-focused coping styles rather than emotion-focused may reduce social anxiety, so future experimental studies can test this idea more rigorously.
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PbTx-2 and okadaic acid (OA) are two typical marine toxins that are highly toxic and harmful to human health. The approach based on citrate-capped gold nanoparticles (Cit-AuNPs) and specific aptamers to construct label-free colorimetric sensors is a widely used method for marine toxin detection. However, the potential interactions between Cit-AuNPs and target molecules have always been ignored, which may result in wrong analytical results due to shortcomings in the Cit-AuNPs. To overcome these shortfalls, in this work, AuNPs were synthesized using tyrosine as a reducing and capping agent, and a robust colorimetric aptasensor based on tyrosine-capped AuNPs (Tyr-AuNPs) was constructed for the label-free detection of marine toxins. Tyr-AuNPs presented better stability compared to Cit-AuNPs due to the stronger binding of amine groups on tyrosine to AuNPs through the Au-N bond. Interactions between Tyr-AuNPs and PbTx-2 were analyzed through UV-vis and isothermal titration calorimetry methods and the results validated the robustness of the Tyr-AuNPs. Colorimetric aptasensors were established for PbTx-2 and OA detection with a linear range of 0.05-4 ppm and limits of detection of 2.25 ppb and 5.19 ppb, respectively. These results demonstrate that the developed colorimetric aptasensor can be a robust and promising method for marine toxin detection.
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Aptámeros de Nucleótidos , Técnicas Biosensibles , Nanopartículas del Metal , Humanos , Oro/química , Colorimetría/métodos , Nanopartículas del Metal/química , Tirosina , Ácido Ocadaico , Aptámeros de Nucleótidos/química , Límite de Detección , Técnicas Biosensibles/métodosRESUMEN
Previous research on the relationship between parenting style and social anxiety in Chinese youth has been inconsistent, which has made it difficult to consider whether improving parenting may serve as a preventative intervention for social anxiety. The current study aimed to clarify these inconsistencies by examining the strength of the association between positive/negative parenting style and social anxiety among Chinese students and the role of certain moderators in those associations. A meta-analysis was conducted on 53 studies with a total sample of 26,024 Chinese mainland students. Separate analyses were conducted for positive parenting style and social anxiety (N = 24,081), and negative parenting style and social anxiety (N = 24,933). Findings suggest a small negative association exists between positive parenting style and social anxiety, and a small positive association exists between negative parenting style and child social anxiety. Analyses suggested type of social anxiety measures, developmental stage, and gender all moderated the relationships between parenting style and social anxiety. Results clarify the direction of the relationship between parenting and social anxiety amongst Chinese youth and point to particular implications and future directions for policy, practice, and research.
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Gastric cancer (GC) is one of the most fatal common cancers in worldwide. Helicobacter pylori (H. pylori) infection is closely related to the development of GC, although the mechanism is still unclear. In our study, we aim to develop a robust messenger RNA (mRNA) signature associated with H. pylori (-) GC that can sensitively and efficiently predict the prognostic. The RNA-seq expression profile and corresponding clinical data of 598 gastric cancer samples and 63 normal samples obtained from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus database. Using gene set enrichment analysis H. pylori (+) GC and H. pylori (-) GC patients and normal samples to select certain genes for further analysis. Using univariate and multivariate Cox regression model to establish a gene signature for predicting the overall survival (OS). Finally, we identified G2/M related seven-mRNA signature (TGFB1, EGF, MKI67, ILF3, INCENP, TNPO2, and CHAF1A) closely related to the prognosis of patients with H. pylori (-) GC. The seven-mRNA signature was identified to act as an independent prognostic biomarker by stratified analysis and multivariate Cox regression analysis. It was also validated on two test groups from TCGA and GSE15460 and shown that patients with high-risk scores based on the expression of the seven mRNAs had significantly shorter survival times compared to patients with low-risk scores (P < .0001). In this study, we developed a seven-mRNA signature related to G2/M checkpoint from H. pylori (-) GCs that as an independent biomarker potentially with a good performance in predicting OS and might be valuable for the clinical management for patients with GC.
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Biomarcadores de Tumor/genética , Regulación Neoplásica de la Expresión Génica , Redes Reguladoras de Genes , Infecciones por Helicobacter/complicaciones , Helicobacter pylori/aislamiento & purificación , Interacciones Huésped-Patógeno/genética , Neoplasias Gástricas/patología , Femenino , Perfilación de la Expresión Génica , Infecciones por Helicobacter/virología , Humanos , Masculino , ARN Neoplásico/análisis , ARN Neoplásico/genética , Neoplasias Gástricas/genética , Neoplasias Gástricas/virologíaRESUMEN
BACKGROUND: Increasing studies have suggested that aberrant expression of microRNAs might play essential roles in the progression of cancers. In this study, we sought to construct a high-specific and superior microRNAs signature to improve the survival prediction of colon adenocarcinoma (COAD) patients. METHODS: The genome-wide miRNAs, mRNA and lncRNA expression profiles and corresponding clinical information of COAD were collected from the TCGA database. Differential expression analysis, Kaplan-Meier curve and time-dependent ROC curve were calculated and performed using R software and GraphPad Prism7. Univariate and multivariate Cox analysis was performed to evaluate the prognostic ability of signature. Functional enrichment analysis was analyzed using STRING database. RESULTS: We identified ten prognosis-related microRNAs, including seven risky factors (hsa-miR-197, hsa-miR-32, hsa-miR-887, hsa-miR-3199-2, hsa-miR-4999, hsa-miR-561, hsa-miR-210) and three protective factors (hsa-miR-3917, hsa-miR-3189, hsa-miR-6854). The Kaplan-Meier survival analysis showed that the patients with high risk score had shorter overall survival (OS) in test series. And the similar results were observed in both validation and entire series. The time-dependent ROC curve suggested this signature have high accuracy of OS for COAD. The Multivariate Cox regression analysis and stratification analysis suggested that the ten-microRNA signature was an independent factor after being adjusted with other clinical characteristics. In addition, we also found microRNA signature have higher AUC than other signature. Furthermore, we identified some miRNA-target genes that affect lymphatic metastasis and invasion of COAD patients. CONCLUSION: In this study, we established a ten-microRNA signature as a potentially reliable and independent biomarker for survival prediction of COAD patients.
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BACKGROUND: Triple negative breast cancer (TNBC) is a specific subtype of breast cancer with a poor prognosis due to its aggressive biological behaviour and lack of therapeutic targets. We aimed to explore some novel genes and pathways related to TNBC prognosis through bioinformatics methods as well as potential initiation and progression mechanisms. METHODS: Breast cancer mRNA data were obtained from The Cancer Genome Atlas database (TCGA). Differential expression analysis of cancer and adjacent cancer, as well as, triple negative breast cancer and non-triple negative breast cancer were performed using R software. The key genes related to the pathogenesis were identified by functional and pathway enrichment analysis and protein-protein interaction network analysis. Based on univariate and multivariate Cox proportional hazards model analyses, a gene signature was established to predict overall survival. Receiver operating characteristic curve was used to evaluate the prognostic performance of our model. RESULTS: Based on mRNA expression profiling of breast cancer patients from the TCGA database, 755 differentially expressed overlapping mRNAs were detected between TNBC/non-TNBC samples and normal tissue. We found eight hub genes associated with the cell cycle pathway highly expressed in TNBC. Additionally, a novel six-gene (TMEM252, PRB2, SMCO1, IVL, SMR3B and COL9A3) signature from the 755 differentially expressed mRNAs was constructed and significantly associated with prognosis as an independent prognostic signature. TNBC patients with high-risk scores based on the expression of the 6-mRNAs had significantly shorter survival times compared to patients with low-risk scores (P < 0.0001). CONCLUSIONS: The eight hub genes we identified might be tightly correlated with TNBC pathogenesis. The 6-mRNA signature established might act as an independent biomarker with a potentially good performance in predicting overall survival.
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A light-addressable potentiometric sensor (LAPS) is a semiconductor electrochemical sensor based on the field-effect which detects the variation of the Nernst potential on the sensor surface, and the measurement area is defined by illumination. Thanks to its light-addressability feature, an LAPS-based chemical imaging sensor system can be developed, which can visualize the two-dimensional distribution of chemical species on the sensor surface. This sensor system has been used for the analysis of reactions and diffusions in various biochemical samples. In this review, the LAPS system set-up, including the sensor construction, sensing and substrate materials, modulated light and various measurement modes of the sensor systems are described. The recently developed technologies and the affecting factors, especially regarding the spatial resolution and temporal resolution are discussed and summarized, and the advantages and limitations of these technologies are illustrated. Finally, the further applications of LAPS-based chemical imaging sensors are discussed, where the combination with microfluidic devices is promising.
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Baicalein, a famously effective component of the traditional Chinese medicine Rhizoma Huang Qin (Scutellaria altissima L.), has been proved to have potent neuroprotection and anti-platelet aggregation effects with few side effects. Meanwhile, recent studies have revealed that the introduction of amino acid to baicalein could improve its neuroprotective activity. In the present study, a series of novel baicalein amino acid derivatives were designed, synthesized, and screened for their neuroprotective effect against tert-butyl, hydroperoxide-induced, SH-SY5Y neurotoxicity cells and toxicity on the normal H9C2 cell line by standard methylthiazol tetrazolium (MTT) assay. In addition, all of the newly synthesized compounds were characterized by 1H-NMR, 13C-NMR, and high resolution mass spectrometry (HR-MS). The results showed that most of the compounds provided more potent neuroprotection than baicalein, and were equivalent to the positive drug edaravin. They showed no obvious cytotoxicity on normal H9C2 cells. Notably, the most active compound 8 displayed the highest protective effect (50% effective concentration (EC50) = 4.31 µM) against tert-butyl, hydroperoxide-induced, SH-SY5Y neurotoxicity cells, which was much better than the baicalein (EC50 = 24.77 µM) and edaravin (EC50 = 5.62 µM). Further research on the chick chorioallantoic membrane (CAM) model indicated that compound 8 could significantly increase angiogenesis, which might promote neurovascular proliferation. The detection of apoptosis analysis showed that compound 8 could dramatically alleviate morphological manifestations of cell damage. Moreover, the benzyloxycarbonyl (cbz)-protected baicalein amino acid derivatives showed better neuroprotective activity than the t-Butyloxy carbonyl (boc)-protected derivatives.
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Aminoácidos/química , Flavanonas/síntesis química , Flavanonas/farmacología , Fármacos Neuroprotectores/síntesis química , Fármacos Neuroprotectores/farmacología , Inductores de la Angiogénesis/química , Inductores de la Angiogénesis/farmacología , Animales , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Técnicas de Química Sintética , Embrión de Pollo , Relación Dosis-Respuesta a Droga , Flavanonas/química , Humanos , Concentración 50 Inhibidora , Estructura Molecular , Fármacos Neuroprotectores/química , Relación Estructura-ActividadRESUMEN
OBJECTIVE: Rising concerns over wellness and aging have heightened the demand for convenient and efficient on-site health monitoring and disease screening. Current research, focused on specific biomarker detection, often neglects the complexities of sample matrix interference and the absence of a comprehensive, automated platform. To address these issues, we have developed a universal, fully automated analyzer for multifaceted, on-site biochemical analysis of body fluids. METHODS: This analyzer integrates automated sample pretreatment, automatic dilution, detection, and self-cleaning functionalities seamlessly. It is designed to detect a wide range of analytes, from small molecules to macromolecules, including ions and proteins, utilizing spectrophotometric sensing. After optimization, the analyzer achieves performance comparable to traditional Enzyme-Linked Immunosorbent Assay (ELISA), while significantly expanding its detection range through automated dilution. RESULTS: Demonstrations of small molecule detection include the simultaneous assessment of citric acid (CA) and oxalic acid (OA) in urine, achieving recovery rates between 96.65%-106.42% and 93.13%-112.50%, respectively. For protein detection, the analyzer successfully identified Cyfra21-1 in saliva with a recovery rate of 104.93%-111.31%. The pre-treatment process requires only 8.8 minutes, showing enhanced recovery rates for CA and OA at 97.8% and 97.6% respectively, which are superior and more rapid than manual methods. CONCLUSION: The exemplary pretreatment and detection performance of the analyzer underlines its effectiveness in multifaceted, on-site biomarker detection, establishing it as a promising and versatile tool for disease screening and health monitoring. SIGNIFICANCE: This analyzer offers a powerful technological solution for on-site fluid testing, advancing community health care by facilitating more reliable and rapid diagnostics.
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Via an insufficient coat protein complex I (COPI) retrieval signal, the majority of SARS-CoV-2 spike (S) is resident in host early secretory organelles and a tiny amount is leaked out in cell surface. Only surface-exposed S can be recognized by B cell receptor (BCR) or anti-S therapeutic monoclonal antibodies (mAbs) that is the trigger step for B cell activation after S mRNA vaccination or infected cell clearance by S mAbs. Now, a drug strategy to promote S host surface exposure is absent. Here, we first combined structural and biochemical analysis to characterize S COPI sorting signals. A potent S COPI sorting inhibitor was then invented, evidently capable of promoting S surface exposure and facilitating infected cell clearance by S antibody-dependent cellular cytotoxicity (ADCC). Importantly, with the inhibitor as a probe, we revealed Omicron BA.1 S is less cell surface exposed than prototypes because of a constellation of S folding mutations, possibly corresponding to its ER chaperone association. Our findings not only suggest COPI is a druggable target against COVID-19, but also highlight SARS-CoV-2 evolution mechanism driven by S folding and trafficking mutations.
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The C-glycosidic bond that connects the sugar moiety with aglycone is difficult to be broken or made due to its inert nature. The knowledge of C-glycoside breakdown and synthesis is very limited. Recently, the enzyme DgpA/B/C cascade from a human intestinal bacterium PUE was identified to specifically cleave the C-glycosidic bond of puerarin (daidzein-8-C-glucoside). Here we investigated how puerarin is recognized and oxidized by DgpA based on crystal structures of DgpA with or without substrate and biochemical characterization. More strikingly, we found that apart from being a C-glycoside cleaving enzyme, DgpA/B/C is capable of efficiently converting O- to C-glycoside showing the activity as a structure isomerase. A possible mechanistic model was proposed dependently of the simulated complex structure of DgpB/C with 3â³-oxo-daidzin and structure-based mutagenesis. Our findings not only shed light on understanding the enzyme-mediated C-glycosidic bond breakage and formation, but also may help to facilitate stereospecific C-glycoside synthesis in pharmaceutical industry.
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This study applied cognitive diagnostic models to assess students' learning progressions in energy. A Q-matrix (i.e., an item attribute alignment table) was proposed based on existing literature about learning progressions of energy in the physical science domain and the Trends in International Mathematics and Science Study (TIMSS) assessment framework. The Q-matrix was validated by expert review and real data analysis. Then, the deterministic inputs, noisy 'and' gate (DINA) model with hierarchical relations was applied to data from three jurisdictions that had stable, defined science curricula (i.e., Australia, Hong Kong, and Ontario). The results suggested that the hypothesized learning progression was consistent with the observed progression in understanding the energy concept. We also found similarities in students' attribute mastery across the three jurisdictions. In addition, we examined the instructional sensitivity of the selected item. We discuss several curriculum-related issues and student misconceptions that may affect students' learning progressions and mastery patterns in different regions of the world.
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The design-on-demand of lignocellulose nanofibril-based materials for contaminant disposal is worth exploring. Herein, we mildly extract sulfated lignocellulose nanofibrils from bagasse via a deep eutectic solvent-based approach, and use them as a matrix for TiO2 nanoparticles (TNPs) towards adsorption-photocatalytic synergistic removal of tetracycline (TC). The resultant lignocellulose-based nanocomposite aerogel possessing a high specific surface area (95.3 m2/g), surface charge density (1.78 mmol/g) and well-preserved lignocellulosic structure, strongly adsorbed TC with a maximum adsorption capacity of 70 mg/g via a combination of intermolecular interactions (i.e., hydrogen bonding and π-π stacking) and electrostatic forces. Furthermore, the excellent photocatalytic activity of uniformly distributed TNPs in combination with the outstanding adsorption capacity of nanocomposite aerogel can synergistically remove TC in a dynamic and continuous process, during which ~90 % TC (10 mg/L) was efficiently removed within 40 min. HPLC-MS was performed to reveal the degradation pathways of TC. Meanwhile, our developed nanocomposite aerogel demonstrated favorable structural stability and recyclability, which together supported its durability for environmental remediation.
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Compuestos Heterocíclicos , Contaminantes Químicos del Agua , Adsorción , Antibacterianos/química , Lignina , Sulfatos , Óxidos de Azufre , Tetraciclina/química , Contaminantes Químicos del Agua/químicaRESUMEN
The accumulation of dissolved and colloidal substances (DCS) in the increasingly closed paper circulating water system can seriously lower the productivity and safety of papermaking machines, and it has been a challenge to develop an adsorbent with low cost, high adsorption efficiency and large adsorption capacity for DCS removal. In this study, cationic lignocellulose nanofibers (CLCNF) were obtained by cationic modification of agricultural waste bagasse in deep eutectic solvents (DES) followed by mechanical defibrillation, and then CLCNF were employed as an adsorbent for DCS model contaminant polygalacturonic acid (PGA) removal. CLCNF was characterized by transmission electron microscopy, Fourier transform infrared, elemental analysis, X-ray diffraction, and thermogravimetric analysis. The analytical results confirmed the successful preparation of CLCNF with 4.6-7.9 nm diameters and 0.97-1.76 mmol/g quaternary ammonium groups. The effects of quaternary ammonium group contents, pH, contact time and initial concentration of PGA on the adsorption were investigated in a batch adsorption study. According to the results, the cationic modification significantly enhanced the adsorption of PGA by CLCNF and the adsorption performance increased with the increase of the quaternary ammonium group contents. The adsorption of PGA on CLCNF followed the pseudo-second-order and the fitted Langmuir isotherm model. The adsorption showed fast initial kinetics and the experimental maximum adsorption capacity was 1054 mg/g, which is much higher than PGA adsorbents previously reported in the literature. Therefore, CLCNF with high cationic group content developed in this paper is a promising adsorbent for DCS removal.
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Citric acid (CA) has been considered as a biomarker of urolithiasis due to its vital suppression role in urinary stone formation. Most analytical methods for detecting CA are complicated and require expensive equipment. Herein, a colorimetric method based on sodium dodecylsulfate (SDS) modified AgNPs was presented for convenient and portable detection of CA in urine. By detecting the absorption of the solution color, the quantitative detection of CA can be achieved. The pH value of SDS-AgNPs, concentration of Al3+ and incubation time were optimized. Under optimal conditions, the method has the detection range of 1-10 mg/L, with a limit of detection (LOD) of 0.21 mg/L. Moreover, a self-developed portable CD(Compact Disk)-spectrometer (CDs) was established for detecting CA with a LOD of 0.49 mg/L featuring high simplicity, low time cost and good portability. This method was also validated with good selectivity to CA. In addition, the artificial urine samples were also detected to verify the capability of the method and CDs. The results validated that the method integrating with the CDs can be a promising platform for citric acid detection that can be further used for early screening and prognostic monitoring of urolithiasis.
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Nanopartículas del Metal , Urolitiasis , Biomarcadores , Ácido Cítrico , Colorimetría , Humanos , Plata , Sodio , Dodecil Sulfato de Sodio , Urolitiasis/diagnósticoRESUMEN
Heavy metal pollution has severe threats to the ecological environment and human health. Thus, it is urgent to achieve the rapid, selective, sensitive and portable detection of heavy metal ions. To overcome the defects of traditional methods such as time-consuming, low sensitivity, high cost and complicated operation, QDs (Quantum dots)-based nanomaterials have been used in sensors to significantly improve the sensing performance. Due to their excellent physicochemical properties, high specific surface area, high adsorption and reactive capacity, nanomaterials could act as potential probes or offer enhanced sensitivity and create a promising nanosensors platform. In this review, the rapidly advancing types of QDs for heavy metal ions detection are first summarized. Modified with ligands, nanomaterials, or biomaterials, QDs are assembled on sensors by the interaction of electrostatic adsorption, chemical bonding, steric hindrance, and base-pairing. The stability of QDs-based nanosensors is improved by doping the elements to QDs, providing the reference substance, optimizing the assemble strategies and so on. Then, according to transducer principles, the two most typical sensor categories based on QDs: optical and electrochemical sensors are highlighted to be discussed. In the meanwhile, portable devices combining with QDs to adapt the practical detection in complex situations are summarized. The deficiencies and future challenges of QDs in toxicity, specificity, portability, multi-metal co-detection and degradation during the detection are also pointed out. In the end, the development trends of QDs-based nanosensors for heavy metal ions detection are discussed. This review presents an overall understanding, recent advances, current challenges and future outlook of QDs-based nanosensors for heavy metal detection.
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Metales Pesados , Nanoestructuras , Puntos Cuánticos , Humanos , Iones , TransductoresRESUMEN
Malnutrition is a common complication in children with cancer. Cancer treatment and malnutrition can disrupt gut microbiome diversity and composition. The gut microbiome is of broad interest to better understand the mechanisms of malnutrition in cancer therapy. This study aimed to compare the gut microbiome between children with solid tumors postchemotherapy and healthy controls, and investigated the association of the putative microbiome differences with diet. Study participants were 27 children (7-18 years) with solid tumors within the first year after the completion of chemotherapy and 22 healthy controls. The study groups did not have a statistically significant difference in age, race, sex, and body mass index. At study intake, the participants completed the Block Kids Food Screener for dietary intakes in the past week. Fecal specimens were collected and analyzed for the gut microbiome. The cancer and control groups differed in gut microbial ß-diversity and abundance analyses. The macronutrient intakes such as carbohydrates, fiber, beta-carotene, and vitamin B6 were positively associated with α-diversity. Children with adequate vitamin B6 had a higher Chao1 diversity index than children with inadequate or excessive intake (p = 0.0004). Children with excessive selenium intake had a trend for higher Pielou's_e index than children with inadequate intake (p = 0.091). Maintaining a healthy gut microbiome is critical among children with cancer. This study provides new insights on the linkages between dietary intakes and the gut microbiome in children with solid tumors postchemotherapy. These findings, if replicated in future independent studies, may help anticipate malnutrition and plan for personalized nutrition approaches during chemotherapy in pediatric cancers.