Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 236
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
J Cell Mol Med ; 28(18): e70094, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39317949

RESUMEN

Cancer is the leading public health problem worldwide. However, the side effects accompanying anti-cancer therapies, particularly those pertaining to cardiotoxicity and adverse cardiac events, have been the hindrances to treatment progress. Long QT syndrome (LQTS) is one of the major clinic manifestations of the anti-cancer drug associated cardiac dysfunction. Therefore, elucidating the relationship between the LQTS and cancer is urgently needed. Transcriptomic sequencing data and clinic information of 10,531 patients diagnosed with 33 types of cancer was acquired from TCGA database. A pan-cancer applicative gene prognostic model was constructed based on the LQTS gene signatures. Meanwhile, transcriptome data and clinical information from various cancer types were collected from the GEO database to validate the robustness of the prognostic model. Furthermore, the expression level of transcriptomes and multiple clinical features were integrated to construct a Nomo chart to optimize the prognosis model. The ssGSEA analysis was employed to analysis the correlation between the LQTS gene signatures, clinic features and cancer associated signalling pathways. Our findings revealed that patients with lower LQTS gene signatures enrichment levels exhibit a poorer prognosis. The correlation of enrichment levels with the typical pathways was observed in multiple cancers. Then, based on the 17 LQTS gene signatures, we construct a prognostic model through the machine-learning approaches. The results obtained from the validation datasets and training datasets indicated that our prognostic model can effectively predict patient outcomes across diverse cancer types. Finally, we integrated this model with clinical features into a nomogram, demonstrating its potential as a valuable prognostic tool for cancer patients. Our study sheds light on the intricate relationship between LQTS and cancer pathways. A LQTS feature based clinic decision tool was developed aiming to enhance precision treatment of cancer.


Asunto(s)
Síndrome de QT Prolongado , Neoplasias , Humanos , Síndrome de QT Prolongado/genética , Neoplasias/genética , Pronóstico , Transcriptoma/genética , Regulación Neoplásica de la Expresión Génica , Perfilación de la Expresión Génica , Bases de Datos Genéticas , Biología Computacional/métodos , Biomarcadores de Tumor/genética , Nomogramas , Aprendizaje Automático
2.
EMBO J ; 39(14): e104389, 2020 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-32484956

RESUMEN

In bacteria, σ28 is the flagella-specific sigma factor that targets RNA polymerase (RNAP) to control the expression of flagella-related genes involving bacterial motility and chemotaxis. However, the structural mechanism of σ28 -dependent promoter recognition remains uncharacterized. Here, we report cryo-EM structures of E. coli σ28 -dependent transcribing complexes on a complete flagella-specific promoter. These structures reveal how σ28 -RNAP recognizes promoter DNA through strong interactions with the -10 element, but weak contacts with the -35 element, to initiate transcription. In addition, we observed a distinct architecture in which the ß' zinc-binding domain (ZBD) of RNAP stretches out from its canonical position to interact with the upstream non-template strand. Further in vitro and in vivo assays demonstrate that this interaction has the overall effect of facilitating closed-to-open isomerization of the RNAP-promoter complex by compensating for the weak interaction between σ4 and -35 element. This suggests that ZBD relocation may be a general mechanism employed by σ70 family factors to enhance transcription from promoters with weak σ4/-35 element interactions.


Asunto(s)
Proteínas Bacterianas , ADN Bacteriano , Escherichia coli , Regiones Promotoras Genéticas , Factor sigma , Transcripción Genética , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/ultraestructura , Microscopía por Crioelectrón , ADN Bacteriano/metabolismo , ADN Bacteriano/ultraestructura , Escherichia coli/metabolismo , Escherichia coli/ultraestructura , Dominios Proteicos , Factor sigma/metabolismo , Factor sigma/ultraestructura
3.
Anal Chem ; 96(6): 2651-2657, 2024 02 13.
Artículo en Inglés | MEDLINE | ID: mdl-38306178

RESUMEN

In vivo sensing of the dynamics of ions with high selectivity is essential for gaining molecular insights into numerous physiological and pathological processes. In this work, we report an ion-selective micropipette sensor (ISMS) through the integration of functional crown ether-encapsulated metal-organic frameworks (MOFs) synthesized in situ within the micropipette tip. The ISMS features distinctive sodium ion (Na+) conduction and high selectivity toward Na+ sensing. The selectivity is attributed to the synergistic effects of subnanoconfined space and the specific coordination of 18-crown-6 toward potassium ions (K+), which largely increase the steric hindrance and transport resistance for K+ to pass through the ISMS. Furthermore, the ISMS exhibits high stability and sensitivity, facilitating real-time monitoring of Na+ dynamics in the living rat brain during spreading of the depression events process. In light of the diversity of crown ethers and MOFs, we believe this study paves the way for a nanofluidic platform for in vivo sensing and neuromorphic electrochemical sensing.


Asunto(s)
Éteres Corona , Estructuras Metalorgánicas , Éteres Corona/química , Sodio/química , Iones/química , Potasio/química
4.
J Virol ; 97(11): e0113723, 2023 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-37855619

RESUMEN

IMPORTANCE: The ongoing COVID-19 pandemic has been characterized by the emergence of new SARS-CoV-2 variants including the highly transmissible Omicron XBB sublineages, which have shown significant resistance to neutralizing antibodies (nAbs). This resistance has led to decreased vaccine effectiveness and therefore result in breakthrough infections and reinfections, which continuously threaten public health. To date, almost all available therapeutic nAbs, including those authorized under Emergency Use Authorization nAbs that were previously clinically useful against early strains, have recently been found to be ineffective against newly emerging variants. In this study, we provide a comprehensive structural basis about how the Class 3 nAbs, including 1G11 in this study and noted LY-CoV1404, are evaded by the newly emerged SARS-CoV-2 variants.


Asunto(s)
Anticuerpos Neutralizantes , COVID-19 , Pandemias , Humanos , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales , Infección Irruptiva , COVID-19/inmunología , COVID-19/virología
5.
Cancer Cell Int ; 24(1): 114, 2024 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-38528618

RESUMEN

BACKGROUND: Esophageal squamous cell carcinoma (ESCC) is one of the leading causes of digestive system tumor related death in the world. Unfortunately, effective chemopreventive agent is lack for patients with ESCC in clinical practice, which leads to the extremely high mortality rate. METHODS: A library of prescribed drugs was screened for finding critical anti-tumor properties in ESCC cells. The phosphoproteomics, kinase array, pulldown assay and drug affinity responsive target stabilization assay (DARTS) were applied to explore mechanisms and searched for synergistic targets. Established models of PDX in mice were used to determine the therapeutic effect of domperidone. RESULTS: After screening a library of prescribed drugs, we discovered that domperidone has anti-tumor properties. Domperidone, acting as a gastroprokinetic agent, has been widely used in clinic for gastrointestinal motility disorders. Despite limited research, there are indications that domperidone may have anti-tumor properties. In this study, we determined that domperidone significantly inhibited ESCC proliferation in vitro and in vivo. We employed phosphoproteomics to reveal p-ERK, and p-SMAD3 down-regulation upon domperidone treatment. Then, the results of kinase assay and pulldown assay further validated that domperidone directly combined with MEK1/2 and CDK4, leading to the inhibition of their kinase activity. Furthermore, our results revealed that MEK/ERK and CDK4/SMAD3 signal pathway were major pathways in domperidone against ESCC. CONCLUSION: Collectively, these findings suggest that domperidone serves as an effective "multi-target" inhibitor of MEK1/2 and CDK4, offering potential benefits for the chemoprevention of ESCC.

6.
Clin Exp Rheumatol ; 2024 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-39360363

RESUMEN

OBJECTIVES: Th1/Th2 shift occurs during pregnancy. Systemic lupus erythematosus (SLE) flares may induce the dysregulation of Th1 and Th2 cells. We aimed to investigate the dynamic changes of Th1/Th2 associated transcription factors and cytokines in patients with SLE during pregnancy. METHODS: Twenty-five pregnant patients with SLE and twenty-two healthy age-matched women served as controls from September 2021 to March 2022 were enrolled in the study. Real-time quantitative reverse transcription polymerase chain reaction analysis of peripheral blood mononuclear cells were performed to measure the expression of Th1 specific transcription factors T-bet, cytokine IFN-γ, and Th2 specific transcription factors GATA3, cytokine IL-4. The main statistical analysis methods were t test, Mann-Whitney U-test, Pearson correlation and Spearman rank correlation analysis. RESULTS: The mRNA level of IFN-γ and the relative expression of T-bet/GATA3 and IFN-γ/IL-4 in SLE patients were significantly higher than those in healthy individuals, whereas the GATA3 expression is lower in pregnant patients with SLE (p<0.001, p<0.05, p<0.05 and p<0.01 during the whole pregnancy, respectively; p<0.05, p<0.01, p<0.05 and p<0.05 specifically for the 3rd trimester, respectively). There were significant correlations between T-bet and IFN-γ (r=0.492, p<0.05), and between T-bet/GATA3 and IFN-γ/IL-4 (r=0.482, p<0.05). CONCLUSIONS: Our work indicates that in SLE patients Th1/Th2 shift is blocked with up-regulation of Th1 cell function and insufficient Th2 polarisation during pregnancy, which may be involved in adverse pregnancy outcomes.

7.
Sensors (Basel) ; 24(20)2024 Oct 18.
Artículo en Inglés | MEDLINE | ID: mdl-39460186

RESUMEN

The primary objective of modal identification for variable thickness quartz plates is to ascertain their dominant operating mode, which is essential for examining the vibration of beveled quartz resonators. These beveled resonators are plate structures with varying thicknesses. While the beveling process mitigates some spurious modes, it still presents challenges for modal identification. In this work, we introduce a modal identification technique based on the energy method. When a plate with variable thickness is in a resonant state of thickness-shear vibration, the proportions of strain energy and kinetic energy associated with the thickness-shear mode in the total energy reach their peak values. Near this frequency, their proportions are the highest, aiding in identifying the dominant mode. Our research was based on the Mindlin plate theory, and appropriate modal truncation were conducted by retaining three modes for the coupled vibration analysis. The governing equation of the coupled vibration was solved for eigenvalue problem, and the modal energy proportions were calculated based on the determined modal displacement and frequency. Finally, we computed the eigenvalue problems at different beveling time, as well as the modal energies associated with each mode. By calculating the energy proportions, we could clearly identify the dominant mode at each frequency. Our proposed method can effectively assist engineers in identifying vibration modes, facilitating the design and optimization of variable thickness quartz resonators for sensing applications.

8.
Mol Carcinog ; 62(4): 517-531, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36645220

RESUMEN

Esophageal squamous cell carcinoma (ESCC) accounts for 90% of esophageal cancers and has a high mortality rate worldwide. The 5-year survival rate of ESCC patients in developing countries is <20%. Hence, there is an urgent need for developing new and effective treatments that are based on newly-discovered emerging molecules and pathways to prevent ESCC occurrence and recurrence. We investigated the effects of Daurisoline, a bis-benzylisoquinoline alkaloid extracted from the rhizome of menisperum dauricum, on ESCC cell proliferation and elucidated the molecular mechanisms underlying its functions. To explore the effects of Daurisoline on ESCC growth in vitro and in vivo, cell proliferation assays and anchorage-independent growth assays were performed and a patient-derived xenograft (PDX) model was established. Subsequently, phosphoproteomics, molecular docking analysis, pull down assays, mutation experiments and in vitro kinase assay were performed to explore the mechanism of Daurisoline's function on ESCC. Daurisoline inhibited ESCC proliferation in vitro and reduced ESCC PDX exnograft growth in vivo by reducing ERK1/2 phosphorylation. Furthermore, it directly bound to MEK1 (at Asn78 and Lys97) and MEK2 (at Asp194 and Asp212) kinases to inactivate the ERK1/2 signaling pathway. Our results suggest that Daurisoline is a dual inhibitor of MEK1 and MEK2 and suppresses ESCC growth both in vitro and in vivo by inactivating the ERK1/2 signaling pathway. This is first report on the use of MEK inhibitor for ESCC and highlights its potential applications for ESCC treatment and prevention.


Asunto(s)
Bencilisoquinolinas , Neoplasias Esofágicas , Carcinoma de Células Escamosas de Esófago , Humanos , Carcinoma de Células Escamosas de Esófago/genética , Neoplasias Esofágicas/genética , Simulación del Acoplamiento Molecular , Proliferación Celular , Ensayos Antitumor por Modelo de Xenoinjerto , Línea Celular Tumoral , Bencilisoquinolinas/farmacología , Regulación Neoplásica de la Expresión Génica
9.
J Transl Med ; 21(1): 52, 2023 01 28.
Artículo en Inglés | MEDLINE | ID: mdl-36707890

RESUMEN

BACKGROUND/AIMS: Arsenic trioxide (ATO) is the first-line therapeutic drug for acute promyelocytic leukemia. However, the cardiotoxicity of ATO limits its clinical application. This study aims to explore the long noncoding RNA (lncRNA) involved molecular mechanism in ATO-induced cardiotoxicity and to identify available prevention strategies. METHODS: ATO was administered to mice or primary cultured mouse cardiomyocytes. Small interfering RNA targeting lncRNA Kcnq1ot1 (si-Kcnq1ot1) was used to knockdown lncRNA Kcnq1ot1. MiR-34a-5p mimic and antisense morpholino oligonucleotide targeting miR-34a-5p (AMO-34a-5p) were used to upregulate and downregulate the expression of miR-34a-5p, respectively. TUNEL staining was conducted to detect cell DNA damage. Flow cytometry assay was used to detect cell apoptosis. Western blot was conducted to detect Bcl-2, Bax and Sirt1 protein expression. Real-time PCR was used to detect lncRNA Kcnq1ot1, miR-34a-5p, and Sirt1 mRNA expression. Dual-luciferase reporter assay was performed to validate the predicted binding site. RESULTS: ATO induced apoptosis in cardiomyocytes both in vivo and in vitro. Simultaneously, the expression of lncRNA Kcnq1ot1 and Sirt1 was downregulated, and miR-34a-5p was upregulated. MiR-34a-5p has binding sites with lncRNA Kcnq1ot1 and Sirt1. Knockdown of lncRNA Kcnq1ot1 induced apoptosis of cardiomyocytes, with increased miR-34a-5p and decreased Sirt1 expression. Inhibition of miR-34a-5p attenuated si-Kcnq1ot1-induced apoptosis in cardiomyocytes. Therefore, the lncRNA Kcnq1ot1/miR-34a-5p/Sirt1 signaling pathway is involved in ATO-induced cardiotoxicity. Propranolol alleviated ATO-induced apoptosis in cardiomyocytes both in vivo and in vitro, which was related to the lncRNA Kcnq1ot1/miR-34a-5p/Sirt1 signaling pathway. CONCLUSION: The lncRNA Kcnq1ot1/miR-34a-5p/Sirt1 pathway is involved in ATO-induced cardiotoxicity. Propranolol can attenuate ATO-induced cardiotoxicity at least partially through the lncRNA Kcnq1ot1/miR-34a-5p/Sirt1 pathway. Combined administration with propranolol may be a new strategy for alleviating the cardiotoxicity of ATO.


Asunto(s)
MicroARNs , ARN Largo no Codificante , Ratones , Animales , Trióxido de Arsénico , MicroARNs/genética , MicroARNs/metabolismo , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Cardiotoxicidad , Sirtuina 1/genética , Propranolol , Apoptosis/genética
10.
Chemistry ; 29(39): e202301163, 2023 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-37093547

RESUMEN

Achieving efficient separation of mono-/multivalent metal ions is essential in various fields, yet it remains a significant challenge. In this work, a metal-organic framework (MOF) array with subnanochannels that exhibit high selectivity and ion permeability in the sieving of mono-/multivalent metal ion was developed. Specifically, we used confined interfacial reaction at room temperature to synthesis the MOF array inside the micrometer through-pores of a polyethylene terephthalate (PET) membrane. The location of the oil/water interface was regulated by adjusting the surface wettability of the PET membrane. By taking advantage of size sieving effect of the subnanochannels of MOF crystals, we were able to effectively separate monovalent metal ions from multivalent metal ions with selectivity reaching up to 3930±373 (e.g., Li+ /Zr4+ ). The fluxes of Li+ ions were observed to be as high as 1.97 mol h-1 m-2 . The MOF array-based membrane with subnanochannels that we have developed exhibits great promise for applications in wastewater treatment, lithium extraction from salt-lake brines, and other related fields.

11.
PLoS Biol ; 18(4): e3000706, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-32310937

RESUMEN

Transcription activation by cyclic AMP (cAMP) receptor protein (CAP) is the classic paradigm of transcription regulation in bacteria. CAP was suggested to activate transcription on class-II promoters via a recruitment and isomerization mechanism. However, whether and how it modifies RNA polymerase (RNAP) to initiate transcription remains unclear. Here, we report cryo-electron microscopy (cryo-EM) structures of an intact Escherichia coli class-II CAP-dependent transcription activation complex (CAP-TAC) with and without de novo RNA transcript. The structures reveal two distinct architectures of TAC and raise the possibility that CAP binding may induce substantial conformational changes in all the subunits of RNAP and transiently widen the main cleft of RNAP to facilitate DNA promoter entering and formation of the initiation open complex. These structural changes vanish during further RNA transcript synthesis. The observations in this study may reveal a possible on-pathway intermediate and suggest a possibility that CAP activates transcription by inducing intermediate state, in addition to the previously proposed stabilization mechanism.


Asunto(s)
Proteína Receptora de AMP Cíclico/química , Proteínas de Escherichia coli/química , Microscopía por Crioelectrón , Proteína Receptora de AMP Cíclico/metabolismo , ARN Polimerasas Dirigidas por ADN/química , ARN Polimerasas Dirigidas por ADN/metabolismo , Visualización de Datos , Proteínas de Escherichia coli/metabolismo , Modelos Moleculares , Complejos Multiproteicos/química , Conformación Proteica , ARN/química , ARN/metabolismo , Factor sigma/química , Factor sigma/metabolismo , Transcripción Genética
12.
Bioorg Chem ; 130: 106267, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36402024

RESUMEN

Among posttranslational modifications, atypical arginine N-glycosylation has drawn increasing interest due to its fundamental role in various cellular procedures and signaling pathways. The efficient synthesis of arginine N-glycosylated substrates, as well as the generation of specific antibodies, remains challenging. This work describes the efficient synthesis of diverse arginine N-glycosylated peptides, in a process termed silver-promoted solid-phase glycosylation (SGG). There are two key features of the SSG strategy: (i) robust synthesis of gram-scale S-alkyl-isothiourea glycosyl donors facilitates the subsequent SSG procedure and (ii) the simultaneous introduction of both the side-chain sugar motif and arginine residue. Notably, our findings, combined with our previous results, provide a toolbox containing diverse S-alkyl-isothiourea glycosyl donors (glucose, galactose, mannose, ribose, xylose, lactose and maltose) as well as the corresponding Arg N-glycosylated peptides. In addition, our toolbox is shown to help investigate specific antibodies and identify multiple potent and precise biochemical tools for exploring arginine N-glycosylation.


Asunto(s)
Arginina , Péptidos , Glicosilación , Arginina/química , Péptidos/química , Anticuerpos , Manosa/química
13.
Int J Clin Pharmacol Ther ; 61(9): 394-403, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37489511

RESUMEN

Acute lung injury (ALI) is a systemic inflammatory response syndrome in the lungs, with a high incidence and fatality rate of 30 - 40%. Despite the abundance of research on the pathogenesis of lung injury and the great progress that has been achieved, the various number of cells, cytokines and inflammatory response pathways involved in the pathogenesis of ALI and their complex relationships - which together constitute the cell network and inflammatory factor network of ALI inflammatory response - demand more attention. This study reviews the formation of this network in the pathogenesis of ALI.


Asunto(s)
Lesión Pulmonar Aguda , Humanos , Lesión Pulmonar Aguda/etiología , Lesión Pulmonar Aguda/metabolismo , Lesión Pulmonar Aguda/patología , Pulmón , Citocinas , Lipopolisacáridos
14.
Int J Mol Sci ; 24(20)2023 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-37894715

RESUMEN

Flower color is a key ornamental trait in plants. The petals of Gloriosa superba 'Rothschildiana' petals undergo a color transformation from yellow to red during their development, but the molecular mechanism of this process remains unexplored. This study examines the anthocyanin profiles and gene expression patterns of 'Rothschildiana' petals across four developmental stages: bud (S1), initial opening (S2), half opening (S3), and full opening stage (S4). A total of 59 anthocyanins were identified with significant increases in cyanidin-3,5-O-diglucoside, cyanidin-3-O-glucoside, pelargonidin-3-O-glucoside, and pelargonidin-3,5-O-diglucoside levels observed during petal maturation. Transcriptome analysis revealed 46 differentially expressed genes implicated in flavonoid and anthocyanin biosynthesis. Additionally, three gene modules were found to be associated with anthocyanin accumulation throughout flower development. Expression levels of genes associated with auxin, abscisic acid, brassinosteroid signaling, and transcription factors such as NACs and WRKYs underwent significant changes and exhibited strong correlations with several flavonoid and anthocyanin biosynthetic genes in these modules. These findings offer novel insights into the molecular underpinnings of flower color variation and lay the groundwork for the improvement of G. superba.


Asunto(s)
Antocianinas , Pigmentación , Pigmentación/genética , Perfilación de la Expresión Génica , Metaboloma , Glucósidos/metabolismo , Flores/metabolismo , Transcriptoma , Regulación de la Expresión Génica de las Plantas
15.
Pharm Biol ; 61(1): 1462-1473, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37691404

RESUMEN

CONTEXT: Diabetic wounds (DW) are a complication of diabetes and slow wound healing is the main manifestation. Methylene blue (MB) has been shown to exhibit therapeutic effects on diabetes-related diseases. OBJECTIVE: To investigate the mechanisms of action of MB-nanoemulsion (NE) in the treatment of DW. MATERIALS AND METHODS: The concentration of MB-NE used in the in vivo and in vitro experiments was 0.1 mg/mL. Streptozocin-induced diabetic mice were used as models. The mice were separated into nondiabetic, diabetic, MB-NE treated, and NE-treated groups. Intervention of high glucose-induced human umbilical vein endothelial cells using MB-NE. The mechanism by which MB-NE promotes DW healing is investigated by combining histological analysis, immunofluorescence analysis, TUNEL and ROS assays and western blotting. RESULTS: In diabetic mice, the MB-NE accelerated DW healing (p < 0.05), promoted the expression of endothelial cell markers (α-SMA, CD31 and VEGF) (p < 0.05), and reduced TUNEL levels. In vitro, MB accelerated the migration rate of cells (p < 0.05); promoted the expression of CD31, VEGF, anti-apoptotic protein Bcl2 (p < 0.05) and decreased the expression of the pro-apoptotic proteins cleaved caspase-3 and Bax (p < 0.05). MB upregulated the expression of Nrf2, catalase, HO-1 and SOD2 (p < 0.05). In addition, MB reduced the immunofluorescence intensity of TUNEL and ROS in cells and reduced apoptosis. The therapeutic effect of MB was attenuated after treatment with an Nrf2 inhibitor (ML385). DISCUSSION AND CONCLUSION: This study provides a foundation for the application of MB-NE in the treatment of DW.


Asunto(s)
Diabetes Mellitus Experimental , Humanos , Animales , Ratones , Diabetes Mellitus Experimental/tratamiento farmacológico , Azul de Metileno/farmacología , Factor 2 Relacionado con NF-E2 , Especies Reactivas de Oxígeno , Factor A de Crecimiento Endotelial Vascular , Células Endoteliales de la Vena Umbilical Humana
16.
Angew Chem Int Ed Engl ; 62(4): e202216530, 2023 Jan 23.
Artículo en Inglés | MEDLINE | ID: mdl-36458952

RESUMEN

Proton conductors have attracted great attention in various fields, especially in energy production. Here, we find that graphdiyne oxide (GDYO), derived from graphdiyne (GDY), features the highest proton conductivity of 0.54 S cm-1 (100 % RH, 348 K) among the oxidized carbon allotropes reported so far. The sp- and sp2 -co-hybridized carbon skeleton of GDY enables GDYO with the giant water uptake, which is 2.4 times larger than that of graphene oxide (GO), resulting in ultrahigh proton conductivity by increasing the proton concentration and proton conduction pathways. This ultrahigh proton conductivity of GDYO is further proved in a methanol fuel cell by using GDYO membrane as proton exchange membrane. The GDYO membrane enables the cell with higher open circuit voltage, larger power density and lower methanol permeability, compared with commercial Nafion 117. Moreover, the GDYO membrane bears high ion exchange capacity, good acidic stability and low swelling ratio.

17.
Angew Chem Int Ed Engl ; 62(21): e202302997, 2023 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-36943400

RESUMEN

Biological ion channels regulate the ion flow across cell membrane via opening or closing of the pores in response to various external stimuli. Replicating the function of high ion gating effects with artificial porous materials has been challenging. Herein, we report that the self-assembled two-dimensional metal-organic framework (MOF) membrane can serve as an excellent nanofluidic platform for smart regulation of ion transport. The MOF membrane with good photothermal performance exhibits extremely high ion gating ratio (up to 104 ), which is among the highest values in MOF membrane nanochannels for light-controlled ion gating reported so far. By repeatedly turning on and off the light, the nanofluidic device shows outstanding stability and reversibility that can be applied in the remote light-switching system. This work may spark promising applications of MOF membrane with variety of stimuli responsive properties in ion sieving, biosensing, and energy conversion.

18.
Angew Chem Int Ed Engl ; 62(2): e202215906, 2023 01 09.
Artículo en Inglés | MEDLINE | ID: mdl-36374215

RESUMEN

Biological ion channels penetrated through cell membrane form unique transport pathways for selective ionic conductance. Replicating the success of ion selectivity with mixed matrix membranes (MMMs) will enable new separation technologies but remains challenging. Herein, we report a soft substrate-assisted solution casting method to develop MMMs with penetrating subnanochannels for selective metal ion conduction. The MMMs are composed of penetrating Prussian white (PW) microcubes with subnanochannels in dense polyimide (PI) matrices, achieving selective monovalent metal ion conduction. The ion selectivity of K+ /Mg2+ is up to 14.0, and the ion conductance of K+ can reach 45.5 µS with the testing diameter of 5 mm, which can be further improved by increasing the testing area. Given the diversity of nanoporous materials and polymer matrices, we expect that the MMMs with penetrating subnanochannels could be developed into a versatile nanofluidic platform for various emerging applications.


Asunto(s)
Metales , Nanoporos , Membrana Celular , Iones , Polímeros
19.
Br J Cancer ; 126(7): 1037-1046, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-34912075

RESUMEN

BACKGROUND: Due to the high recurrence and low 5-year survival rates of esophageal squamous cell carcinoma (ESCC) after treatment, the discovery of novel drugs for recurrence chemoprevention is of particular importance. METHODS: We screened the FDA-approved drug library and found that Nuplazid, an atypical antipsychotic that acts as an effective 5-HT 2 A receptor inverse agonist, could potentially exert anticancer effects in vitro and in vivo on ESCC. RESULTS: Pull-down results indicated that Nuplazid binds with p21-activated kinase 4 (PAK4), and a kinase assay showed that Nuplazid strongly suppressed PAK4 kinase activity. Moreover, Nuplazid exhibited inhibitory effects on ESCC in vivo. CONCLUSIONS: Our findings indicate that Nuplazid can suppress ESCC progression through targeting PAK4.


Asunto(s)
Neoplasias Esofágicas , Carcinoma de Células Escamosas de Esófago , Línea Celular Tumoral , Proliferación Celular , Neoplasias Esofágicas/metabolismo , Carcinoma de Células Escamosas de Esófago/metabolismo , Regulación Neoplásica de la Expresión Génica , Humanos , Piperidinas , Urea/análogos & derivados , Quinasas p21 Activadas/metabolismo
20.
Anal Chem ; 94(10): 4328-4334, 2022 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-35245019

RESUMEN

Nanofluidic ionic diodes have attracted much attention, because of the unique property of asymmetric ion transport and promising applications in molecular sensing and biosensing. However, it remains a challenge to fabricate diode-like nanofluidic system with molecular-size pores. Herein, we report a new and facile approach to construct nanofluidic ionic diode by in situ asymmetric growth of metal-organic frameworks (MOFs) in nanochannels. We implement microwave-assisted strategy to obtain asymmetric distribution of MOFs in porous anodic aluminum oxide with barrier layer on one side. After etching the barrier layer and modifying with positively charged molecules, the nanofluidic device possesses asymmetric geometry and surface charge, performing the ionic current rectification (ICR) behavior in different electrolyte concentrations. Moreover, the ICR ratio is readily regulated with visible light illumination mainly due to the enhancement of surface charge of MOFs, which is further confirmed by finite element simulation. This study provides a reliable way to build the nanofluidic platform for investigating the asymmetric ion transport through the molecular-size pores, which is envisaged to be important for molecular sensing based on ICR with molecular-size pores.


Asunto(s)
Estructuras Metalorgánicas , Óxido de Aluminio , Transporte Iónico , Iones
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA