RESUMO
Gene duplication is increasingly recognized as an important mechanism for the origination of new genes, as revealed by comparative genomic analysis. However, how new duplicate genes contribute to phenotypic evolution remains largely unknown, especially in plants. Here, we identified the new gene EXOV, derived from a partial gene duplication of its parental gene EXOVL in Arabidopsis thaliana. EXOV is a species-specific gene that originated within the last 3.5 million years and shows strong signals of positive selection. Unexpectedly, RNA-sequencing analyses revealed that, despite its young age, EXOV has acquired many novel direct and indirect interactions in which the parental gene does not engage. This observation is consistent with the high, selection-driven substitution rate of its encoded protein, in contrast to the slowly evolving EXOVL, suggesting an important role for EXOV in phenotypic evolution. We observed significant differentiation of morphological changes for all phenotypes assessed in genome-edited and T-DNA insertional single mutants and in double T-DNA insertion mutants in EXOV and EXOVL. We discovered a substantial divergence of phenotypic effects by principal component analyses, suggesting neofunctionalization of the new gene. These results reveal a young gene that plays critical roles in biological processes that underlie morphological evolution in A. thaliana.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Duplicação Gênica , Arabidopsis/genética , Arabidopsis/fisiologia , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Cromossomos de Plantas , Regulação da Expressão Gênica de Plantas , Genes Duplicados , Genética Populacional , Mutação , Fenótipo , Plantas Geneticamente Modificadas , Análise de Componente Principal , Seleção GenéticaRESUMO
Thoracic aortic aneurysm (TAA) is characterized by dilation of the aortic root or ascending/descending aorta. TAA is a heritable disease that can be potentially life threatening. While 10%-20% of TAA cases are caused by rare, pathogenic variants in single genes, the origin of the majority of TAA cases remains unknown. A previous study implicated common variants in FBN1 with TAA disease risk. Here, we report a genome-wide scan of 1,351 TAA-affected individuals and 18,295 control individuals from the Cardiovascular Health Improvement Project and Michigan Genomics Initiative at the University of Michigan. We identified a genome-wide significant association with TAA for variants within the third intron of TCF7L2 following replication with meta-analysis of four additional independent cohorts. Common variants in this locus are the strongest known genetic risk factor for type 2 diabetes. Although evidence indicates the presence of different causal variants for TAA and type 2 diabetes at this locus, we observed an opposite direction of effect. The genetic association for TAA colocalizes with an aortic eQTL of TCF7L2, suggesting a functional relationship. These analyses predict an association of higher expression of TCF7L2 with TAA disease risk. In vitro, we show that upregulation of TCF7L2 is associated with BCL2 repression promoting vascular smooth muscle cell apoptosis, a key driver of TAA disease.
Assuntos
Aneurisma da Aorta Torácica/genética , Diabetes Mellitus Tipo 2/genética , Células Endoteliais/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/genética , Locos de Características Quantitativas , Proteína 2 Semelhante ao Fator 7 de Transcrição/genética , Aorta/metabolismo , Aorta/patologia , Aneurisma da Aorta Torácica/metabolismo , Aneurisma da Aorta Torácica/patologia , Estudos de Casos e Controles , Caspase 3/genética , Caspase 3/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/patologia , Células Endoteliais/patologia , Regulação da Expressão Gênica , Genoma Humano , Estudo de Associação Genômica Ampla , Humanos , Íntrons , Michigan , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/patologia , Mutação , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteína 2 Semelhante ao Fator 7 de Transcrição/metabolismo , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismoRESUMO
Hydrogen peroxide (H2O2) overexpressed in mitochondria has been regarded as a key biomarker in the pathological processes of various diseases. However, there is currently a lack of suitable mitochondria-targetable near-infrared (NIR) probes for the visualization of H2O2 in multiple diseases, such as PM2.5 exposure-induced lung injury, hepatic ischemia-reperfusion injury (HIRI), nonalcoholic fatty liver (NAFL), hepatic fibrosis (HF), and malignant tumor tissues containing clinical cancer patient samples. Herein, we conceived a novel NIR fluorescent probe (HCy-H2O2) by introducing pentafluorobenzenesulfonyl as a H2O2 sensing unit into the NIR hemicyanine platform. HCy-H2O2 exhibits good sensitivity and selectivity toward H2O2, accompanied by a remarkable "turn-on" fluorescence signal at 720 nm. Meanwhile, HCy-H2O2 has stable mitochondria-targetable ability and permits monitoring of the up-generated H2O2 level during mitophagy. Furthermore, using HCy-H2O2, we have successfully observed an overproduced mitochondrial H2O2 in ambient PM2.5 exposure-induced lung injury, HIRI, NAFL, and HF models through NIR fluorescence imaging. Significantly, the visualization of H2O2 has been achieved in both tumor-bear mice as well as surgical specimens of cancer patients, making HCy-H2O2 a promising tool for cancer diagnosis and imaging-guided surgery.
Assuntos
Corantes Fluorescentes , Peróxido de Hidrogênio , Mitocôndrias , Imagem Óptica , Corantes Fluorescentes/química , Corantes Fluorescentes/síntese química , Peróxido de Hidrogênio/metabolismo , Animais , Mitocôndrias/metabolismo , Mitocôndrias/química , Camundongos , Humanos , Lesão Pulmonar/diagnóstico por imagem , Lesão Pulmonar/induzido quimicamente , Lesão Pulmonar/metabolismo , Raios InfravermelhosRESUMO
The presence of abnormal dopamine (DA) levels may cause serious neurological disorders, therefore, the quantitative analysis of DA and its related research are of great significance for ensuring health. Herein, the bovine serum albumin (BSA) template method has been proposed for the preparation of catalytically high-performance ruthenium dioxide/multiwalled carbon nanotube (RuO2/MWCNT) nanocomposites. The incorporation of MWCNTs has improved the active surface area and conductivity while effectively preventing the aggregation of RuO2 nanoparticles. The outstanding electrocatalytic performance of RuO2/MWCNTs has promoted the electro-oxidation of DA at neutral pH. The electrochemical sensing platform based on RuO2/MWCNTs has demonstrated a wide linear range (0.5 to 111.1 µM), low detection limit (0.167 µM), excellent selectivity, long-term stability, and good reproducibility for DA detection. The satisfactory recovery range of 94.7% to 103% exhibited by the proposed sensing podium in serum samples signifies its potential for analytical applications. The aforementioned results reveal that RuO2/MWCNT nanostructures hold promising aptitude in the electrochemical sensor to detect DA in real samples, further offering broad prospects in clinical and medical diagnosis.
Assuntos
Técnicas Biossensoriais , Dopamina , Técnicas Eletroquímicas , Nanotubos de Carbono , Compostos de Rutênio , Soroalbumina Bovina , Animais , Bovinos , Humanos , Técnicas Biossensoriais/métodos , Dopamina/sangue , Técnicas Eletroquímicas/métodos , Limite de Detecção , Nanotubos de Carbono/química , Compostos de Rutênio/química , Soroalbumina Bovina/químicaRESUMO
Proteins encoded by small open reading frames (sORFs) can serve as functional elements playing important roles in vivo. Such sORFs also constitute the potential pool for facilitating the de novo gene birth, driving evolutionary innovation and species diversity. Therefore, their theoretical and experimental identification has become a critical issue. Herein, we proposed a protein-coding sORFs prediction method merely based on integrative sequence-derived features. Our prediction performance is better or comparable compared with other nine prevalent methods, which shows that our method can provide a relatively reliable research tool for the prediction of protein-coding sORFs. Our method allows users to estimate the potential expression of a queried sORF, which has been demonstrated by the correlation analysis between our possibility estimation and codon adaption index (CAI). Based on the features that we used, we demonstrated that the sequence features of the protein-coding sORFs in the two domains have significant differences implying that it might be a relatively hard task in terms of cross-domain prediction, hence domain-specific models were developed, which allowed users to predict protein-coding sORFs both in eukaryotes and prokaryotes. Finally, a web-server was developed and provided to boost and facilitate the study of the related field, which is freely available at http://guolab.whu.edu.cn/codingCapacity/index.html.
Assuntos
Algoritmo Florestas Aleatórias , Fases de Leitura Aberta/genéticaRESUMO
N-type electronic doping of organic semiconductors (OSCs) by using superbase compounds shows high doping efficiency (H. Wei, Z. Cheng, T. Wu, Y. Liu, J. Guo, P.-A. Chen, J. Xia, H. Xie, X. Qiu, T. Liu, B. Zhang, J. Hui, Z. Zeng, Y. Bai and Y. Hu, Adv. Mater. 2023, 35, 2300084). While a deprotonation reaction is believed to trigger the doping process, the detailed mechanism therein is not yet fully understood. In the present work we theoretically study the electronic structure of the deprotonated Phenyl-C61-butyric acid methyl ester (PCBM) molecule, as well as the charge transfer (CT) between PCBM and its deprotonated species. We find that deprotonated PCBM without formation of a new bond between the deprotonated side chain and fullerene induces electronic structure with broken spin symmetry, where an in-gap state is singly occupied by an unpaired electron. A second scenario that we find to be possible is the formation of a new bond between the deprotonated side chain and a fullerene. This leads to a spin symmetric electronic structure with partially localized in-gap state, which is expected to contribute less to the effective doping. These results show that the deprotonated PCBM species without new bond formation predominantly accounts for the effective n-type doping of PCBM, an insight that will be useful for optimization of this recently discovered doping method.
RESUMO
A dual-responsive ratio electrochemical-colorimetric method for nitrite (NO2-) is established based on the combination of nanoenzyme (Mn3O4) catalysis with diazotization reactions. The Mn3O4 can oxidize colorless 3,3',5,5'-tetramethylbenzidine (TMB) into blue TMBox. The NO2- induces the diazotization reaction of TMBox, leading to a decrease of the signal at 652 nm and the generation of a new signal from diazotized TMBox at 445 nm. Furthermore, the presence of NO2- reduces the electrochemical oxidation signal of TMB and simultaneously provides its electrochemical signal. Compared with traditional single-mode detection, dual-mode detection offers higher sensitivity, lower detection limits, and better interference resistance. The inherent advantages of this method make it feasible to detect NO2- in real samples, offering broad prospects for applications in food safety and environmental monitoring.
Assuntos
Benzidinas , Colorimetria , Técnicas Eletroquímicas , Limite de Detecção , Nitritos , Nitritos/análise , Colorimetria/métodos , Técnicas Eletroquímicas/métodos , Benzidinas/química , Contaminação de Alimentos/análise , Oxirredução , Monitoramento Ambiental/métodos , Análise de Alimentos/métodos , CatáliseRESUMO
Abnormal changes occurring in the mitochondrial microenvironment are important markers indicating mitochondrial and cell dysfunction. Herein, we designed and synthesized a multifunctional fluorescent probe DPB that responds to polarity, viscosity, and peroxynitrite (ONOO-). DPB is composed of an electron donor (diethylamine group) and electron acceptor (coumarin, pyridine cations, and phenylboronic acid esters), in which the pyridine group with a positive charge is responsible for targeting to mitochondria. D-π-A structure with strong intramolecular charge transfer (ICT) and twisted intramolecular charge transfer (TICT) properties give rise to respond to polarity and viscosity. The introduction of cyanogroup and phenylboronic acid esters increases the electrophilicity of the probe, which is prone to oxidation triggered by ONOO-. The integrated architecture satisfies the multiple response requirements. As the polarity increases, the fluorescence intensity of probe DPB at 470 nm is quenched by 97%. At 658 nm, the fluorescence intensity of DPB increases with viscosity and decreases with the concentration of ONOO-. Furthermore, the probe is not only successfully used to monitor mitochondrial polarity, viscosity, and endogenous/exogenous ONOO- level fluctuations but also to distinguish cancer cells from normal cells by multiple parameters. Therefore, as-prepared probe provides a reliable tool for better understanding of the mitochondrial microenvironment and also a potential approach for the diagnosis of disease.
Assuntos
Corantes Fluorescentes , Mitocôndrias , Corantes Fluorescentes/química , Viscosidade , Mitocôndrias/química , Microscopia de Fluorescência/métodos , Imagem Óptica/métodos , Piridinas/análise , Ácido Peroxinitroso/análiseRESUMO
Intracellular peroxynitrite anions (ONOO-) and microenvironments (such as viscosity and polarity) play an important role in maintaining redox homeostasis, regulating diffusion, transportation, and signal transduction in living cells. The abnormality of these factors is often closely related to various physiological/pathological processes. However, owing to the lack of suitable probes, the simultaneous visualization of ONOO-, viscosity, and polarity in ferroptosis and cancer models has not been achieved. To meet urgent needs, we presented a multifunctional near-infrared (NIR) fluorescent probe, named MQA-P, for simultaneously detecting ONOO-, viscosity, and polarity within mitochondria. The probe exhibited a remarkable turn-on response to ONOO- with the far-red emission of about 645 nm and was highly sensitive to viscosity/polarity in the NIR channel with λem > 704 nm. Facilitated by MQA-P, for the first time, we revealed that erastin-induced ferroptosis was accompanied by a significant upregulation of ONOO- and an increase of viscosity (or decrease of polarity) at the same time. Moreover, the concurrent use of ONOO-, viscosity, and polarity for the diagnosis of cancer has been successfully achieved not only at cell/tissue levels but also in tumor mice models. Compared with detecting only one factor, this simultaneous detection of multimarkers provides a more sensitive and reliable method/tool for tracking ferroptosis-related pathological processes and cancer diagnosis, holding great potential in preclinical research, medical diagnosis, and imaging-guided surgery.
Assuntos
Ferroptose , Neoplasias , Animais , Camundongos , Corantes Fluorescentes , Viscosidade , Ácido Peroxinitroso , Mitocôndrias , Neoplasias/diagnóstico por imagemRESUMO
Lysosomal viscosity is an essential microenvironment parameter in lysosomes, which is closely associated to the occurrence and development of various diseases, including cancer. Thus, accurately quantifying lysosomal viscosity changes is highly desirable for a better understanding of the dynamics and biological functions of lysosomes. In this study, lysosome self-targetable orange-red emissive carbon dots (OR-CDs) were rationally designed and developed for monitoring lysosomal viscosity fluctuations. The enhanced fluorescence of OR-CDs could be obviously observed as the viscosity increased from 1.07 to 950 cP. Moreover, the as-prepared OR-CDs could quickly enter cells for lysosome-targeting imaging and visualize viscosity variations in living cells and zebrafish. More importantly, by utilizing OR-CDs, we successfully achieved tracing the variations in lysosomal viscosity during the autophagy process. Additionally, as cancer cells possess high viscosity than normal cells, the OR-CDs have been effectively utilized for cancer imaging from cell, tissue, and organ to in vivo levels. It is expected that the developed OR-CDs not only provide a meaningful tool for visualizing investigations of lysosome viscosity-related diseases but also shed light on the development based on the nanomaterial for the clinical diagnosis of cancer.
Assuntos
Pontos Quânticos , Peixe-Zebra , Animais , Carbono , Viscosidade , Lisossomos , Espectrometria de Fluorescência , Corantes FluorescentesRESUMO
The broad application of plastic products has resulted in a considerable release of microplastics (MPs) into the ecosystem. While MPs in other environmental matrices (e.g., soil and water) have been studied for a long time, the atmospheric fine particulate matter (PM2.5)-bound MPs are rarely investigated due to the lack of an appropriate analytical approach. The prevalently used visual and spectroscopic means (e.g., optical microscopy, Fourier-transform infrared spectroscopy, and Raman spectroscopy) suffer from obvious drawbacks that cannot precisely detect MPs of tiny sizes and provide quantitative information. In the present study, a novel strategy that does not require sample pretreatment was developed to first effectuate accurate quantification of polyethylene MP (PE-MP) in PM2.5 based on pyrolysis-gas chromatography-tandem mass spectrometry (Pyr-GC-MS/MS). It featured acceptable recoveries (97%-110%), high sensitivity (LOD = 1 pg), and qualified precisions (RSD of 3%-13%). Employing this approach, for the first time, exact atmospheric concentrations of PE-MPs in PM2.5 from megacities in North (Zhengzhou and Taiyuan) and South (Guangzhou) China were obtained, and relatively serious pollution was found in Taiyuan. The 100% sample detection rates also suggested the widespread occurrence and possible human exposure risks of PM2.5-bound PE-MPs. In brief, the new strategy could conduct direct, sensitive, and accurate quantification of PE-MP in PM2.5, favoring further studies of environmental fates, distributions, and toxicities of atmospheric MPs.
RESUMO
Adipose tissue-derived mesenchymal stem cells (ADSCs) have promising effects on nerve repair due to the differentiation ability to neural cells. Ghrelin has been shown to promote the neural differentiation of ADSCs. This work was designed to explore its underlying mechanism. Herein, we found high expression of LNX2 in ADSCs after neuronal differentiation. Knockdown of LNX2 might block neuronal differentiation of ADSCs, as evidenced by the decreased number of neural-like cells and dendrites per cell, and the reduced expressions of neural markers (including ß-Tubulin III, Nestin, and MAP2). We also demonstrated that LNX2 silencing suppressed the nuclear translocation of ß-catenin in differentiated ADSCs. Luciferase reporter assay indicated that LNX2 inhibited wnt/ß-catenin pathway by reducing its transcriptional activity. In addition, results showed that LNX2 expression was increased by ghrelin, and its inhibition diminished the effects of ghrelin on neuronal differentiation. Altogether, the results suggest that LNX2 is involved in the role of ghrelin to facilitate neuronal differentiation of ADSCs.
Assuntos
Grelina , Células-Tronco Mesenquimais , beta Catenina , beta Catenina/metabolismo , Diferenciação Celular/fisiologia , Células Cultivadas , Grelina/farmacologia , Grelina/metabolismo , Células-Tronco Mesenquimais/metabolismo , Neurônios/metabolismo , HumanosRESUMO
Exome sequencing of genes associated with heritable thoracic aortic disease (HTAD) failed to identify a pathogenic variant in a large family with Marfan syndrome (MFS). A genome-wide linkage analysis for thoracic aortic disease identified a peak at 15q21.1, and genome sequencing identified a novel deep intronic FBN1 variant that segregated with thoracic aortic disease in the family (LOD score 2.7) and was predicted to alter splicing. RT-PCR and bulk RNA sequencing of RNA harvested from fibroblasts explanted from the affected proband revealed an insertion of a pseudoexon between exons 13 and 14 of the FBN1 transcript, predicted to lead to nonsense mediated decay (NMD). Treating the fibroblasts with an NMD inhibitor, cycloheximide, greatly improved the detection of the pseudoexon-containing transcript. Family members with the FBN1 variant had later onset aortic events and fewer MFS systemic features than typical for individuals with haploinsufficiency of FBN1. Variable penetrance of the phenotype and negative genetic testing in MFS families should raise the possibility of deep intronic FBN1 variants and the need for additional molecular studies.
Assuntos
Doenças da Aorta , Síndrome de Marfan , Humanos , Síndrome de Marfan/genética , Fibrilina-1/genética , Mutação , FenótipoRESUMO
Heat shock factor 1 (HSF1) functions to maintain cellular and organismal homeostasis by regulating the expression of target genes, including those encoding heat shock proteins (HSPs). In the present study, the gene encoding HSF1 was cloned from the rice pest Chilo suppressalis, and designated Cshsf1. The deduced protein product, CsHSF1, contained conserved domains typical of the HSF1 family, including a DNA-binding domain, two hydrophobic heptad repeat domains, and a C-terminal transactivation domain. Real-time quantitative PCR showed that Cshsf1 was highly expressed in hemocytes. Expression analysis in different developmental stages of C. suppressalis revealed that Cshsf1 was most highly expressed in male adults. RNAi-mediated silencing of Cshsf1 expression reduced C. suppressalis survival at high temperatures. To investigate the regulatory interactions between Cshsf1 and Cshsps, the promoters and expression patterns of 18 identified Cshsps in C. suppressalis were analysed; four types of heat shock elements (HSEs) were identified in promoter regions including canonical, tail-tail, head-head, and step/gap. The expression of Cshsp19.0, Cshsp21.7B, Cshsp60, Cshsp70 and Cshsp90 was positively regulated by Cshsf1; however, Cshsp22.8, Cshsp702, Cshsp705 and Cshsp706 gene expression was not altered. This study provides a foundation for future studies of HSF1 in insects during thermal stress.
Assuntos
Proteínas de Choque Térmico , Mariposas , Masculino , Animais , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Mariposas/genética , Mariposas/metabolismo , Resposta ao Choque Térmico/genética , Regiões Promotoras Genéticas , Interferência de RNARESUMO
Epidemiological studies suggested that PM2.5 (particle matters with an aerodynamic diameter ≤2.5 µm) exposure is associated with atherosclerosis. Extracellular vesicles (EVs) are messengers between intracellular communications which are important in diseases procession. At present, whether EVs derived from PM2.5-exposed alveolar epithelial cells (P-EVs) involve in atherosclerosis has not been clearly understood. This study is performed to investigate the effects of P-EVs on the development of endothelium adhesion and atherosclerosis. Here, ApoE-/- mice were randomized into different groups receiving one of the following treatments, filtered air (FA), PM2.5, PBS, PBS-treated alveolar epithelial cells-derived EVs (EVs), or P-EVs. Then the atherosclerosis level in aortas or aorta sections was evaluated by oil red O staining. The results indicated that ApoE-/- mice treated with P-EVs or PM2.5 showed more obvious atherosclerosis plaques in aortas and aortic arches than those treated with EVs or PBS. Endothelial cells (ECs) were treated with PBS, EVs, P-EVs, or PM2.5. The adhesion property, miRNAs level and expressions of IκBα, phosphorylated IκBα, NF-κB p65, phosphorylated NF-κB p65, and VCAM1 in ECs were determined. It was found that P-EVs activated IκBα-NF-κB-VCAM1 signaling and increased adhesion of ECs, and such effects could be reversed by adalimumab (the TNF-α inhibitor) or miR-326-3p inhibitor. Further study suggested that P-EVs induced upregulation of TNF-α and miR-326-3p in recipient ECs and contributed to the phosphorylation of NF-κB p65. Collectively, EVs derived from PM2.5-exposed alveolar epithelial cells played an important role in the development of atherosclerosis via activating IκBα-NF-κB-VCAM1 signaling.
Assuntos
Células Epiteliais Alveolares/patologia , Apolipoproteínas E/metabolismo , Aterosclerose/patologia , Adesão Celular/efeitos dos fármacos , Endotélio/patologia , Vesículas Extracelulares/patologia , Material Particulado/efeitos adversos , Células Epiteliais Alveolares/efeitos dos fármacos , Células Epiteliais Alveolares/metabolismo , Animais , Aorta/efeitos dos fármacos , Aorta/metabolismo , Aorta/fisiologia , Aterosclerose/metabolismo , Endotélio/efeitos dos fármacos , Endotélio/metabolismo , Vesículas Extracelulares/efeitos dos fármacos , Vesículas Extracelulares/metabolismo , Camundongos , Placa Aterosclerótica/metabolismo , Placa Aterosclerótica/patologia , Células RAW 264.7 , Transdução de Sinais/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacosRESUMO
Constructing nanozymes with satisfactory catalytic efficiency under physiological conditions is still in great demand for facilitating the advancement of biocatalysts. We herein present a gold nanoparticles-carbon dots nanocomposite (Au-CDs) as an efficient photo-activated nanozyme for monitoring H2O2 released from living cells. The integration of CDs with AuNPs remarkably accelerates the catalytic activity at neutral pH via engaging Mn3+ ions as the mediators. Meanwhile, the reserved cyclodextrin cavities also enhance the adsorption capacity towards chromogenic substrates through host-guest interactions. Moreover, taking advantage of the inhibitory effect of H2O2 on the photo-oxidation ability of the Au-CDs nanocomposite, the Au-CDs based colorimetric method was able to realize in situ assessment of the hydrogen peroxide (H2O2) released from living cells. This method paves a new way to establish a promising biosensing platform for unraveling biological events.
Assuntos
Nanopartículas Metálicas , Nanocompostos , Carbono , Peróxido de Hidrogênio , Ouro , Concentração de Íons de HidrogênioRESUMO
Membrane-based air humidification-dehumidification desalination (MHDD) technology is an effective way to ease fresh water shortage owing to its excellent salt rejection. However, industrial applications pose higher requirements on membrane life expectancy. Membrane cleaning is considered as a potentially sustainable approach to prolong the operation time. Traditional cleaning methods are limited due to the poor recovery efficiency and the introduction of impurities. Here, a novel solar-assisted-self-healing N-doped MXene quantum dots (NMQDs)/ZnO-based membrane was fabricated to repair the water production capability of membranes contaminated by proteins from seawater. On the one hand, NMQDs with up-conversion properties absorb visible light and emit ultraviolet light, under which ZnO could be excited to form electron/hole pairs that help to degrade organic matter pollutants. On the other hand, the addition of NMQDs could improve the charge separation efficiency of ZnO. The synergistic effect of the two enhances the light absorption capacity of ZnO. The as-designed membrane exhibited excellent repair ability. The moisture permeation rate of the healed membrane reached 99.8% of the initial membrane after illumination. The self-healing membrane with solar energy is promising advances in sustainable desalination.
Assuntos
Pontos Quânticos , Óxido de Zinco , Luz , Água do MarRESUMO
In this work, bright yellow fluorescent and multifunctional carbon dots (N-CDs) were prepared by hydrothermal method from O-phenylenediamine and 4-aminobenzoic acid. The fluorescence characterization showed that the N-CDs possessed good optical properties (QY = 32%) and excitation dependent multi-color emission. By exciting with 390 nm, the strong selective interaction of VB12 with N-CDs could result in a sharp decrease in the luminescence of N-CDs at 567 nm. An efficient fluorescence sensor in aqueous solution was constructed which could linearly respond VB12 in wide concentration ranges of 0-90 µM and 140-250 µM. The linear correlation coefficients of N-CDs and VB12 were 0.9950 and 0.9968, respectively, and the detection limit was 0.119 µM. N-CDs were performed for sensitive determination of VB12 in real samples. Moreover, the N-CDs were exploited to image cell. This N-CDs was a sensitive fluorescence probe to monitor VB12 and presented prospective potential in living cells imaging. Schematic diagram of the synthesis process and application research of N-CDs.
RESUMO
A label-free and efficient electrochemical (EC) sensing platform for di-2-ethylhexyl phthalate (DEHP) was developed based on in situ probe nickel hexacyanoferrate nanoparticle (NiHCF NP)-decorated three-dimensional reduced graphene oxide (3D rGO) composites. NiHCF NPs in the composites as an in situ probe show a pair of well-defined peaks with good reversibility and stability. Coupling 3D rGO with NiHCF NPs not only improved the electron transfer capability of NiHCF NPs but also provided more sites for aptamer immobilization. The synthesized NiHCF NP-decorated 3D rGO composites were used to act as a substrate for the immobilization of anti-DEHP aptamer by the covalent bonding method. The designed EC sensing platform displays excellent sensing performance for DEHP with a low detection limit of 3.64 pg/L, and a linear working range of 0.01 - 1000 ng/L. The application of the sensing platform to actual environmental samples was studied and satisfactory results were obtained. Thus, the proposed EC sensing platform would provide a potential tool for efficient detection of pollutants in the environment.
RESUMO
Lung is the largest organ of the respiratory system. During hypoxia, pulmonary cells undergo rapid damage changes and activate the self-rescue pathways, thus leading to complex biomacromolecule modification. Death from mechanical asphyxia refers to death due to acute respiratory disorder caused by mechanical violence. Because of the absence of characteristic signs in corpse, the accurate identification of mechanical asphyxia has always been the difficulty in forensic pathology. This paper reviews the biomacromolecule changes under the pulmonary hypoxia condition and discusses the possibility of application of these changes to accurate identification of death from mechanical asphyxia, aiming to provide new ideas for related research.