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1.
Circ Res ; 134(2): 203-222, 2024 01 19.
Artículo en Inglés | MEDLINE | ID: mdl-38166414

RESUMEN

BACKGROUND: Angiogenesis, which plays a critical role in embryonic development and tissue repair, is controlled by a set of angiogenic signaling pathways. As a TF (transcription factor) belonging to the basic helix-loop-helix family, HEY (hairy/enhancer of split related with YRPW motif)-1 (YRPW motif, abbreviation of 4 highly conserved amino acids in the motif) has been identified as a key player in developmental angiogenesis. However, the precise mechanisms underlying HEY1's actions in angiogenesis remain largely unknown. Our previous studies have suggested a potential role for posttranslational SUMOylation in the dynamic regulation of vascular development and organization. METHODS: Immunoprecipitation, mass spectrometry, and bioinformatics analysis were used to determine the biochemical characteristics of HEY1 SUMOylation. The promoter-binding capability of HEY1 was determined by chromatin immunoprecipitation, dual luciferase, and electrophoretic mobility shift assays. The dimerization pattern of HEY1 was determined by coimmunoprecipitation. The angiogenic capabilities of endothelial cells were assessed by CCK-8 (cell counting kit-8), 5-ethynyl-2-deoxyuridine staining, wound healing, transwell, and sprouting assays. Embryonic and postnatal vascular growth in mouse tissues, matrigel plug assay, cutaneous wound healing model, oxygen-induced retinopathy model, and tumor angiogenesis model were used to investigate the angiogenesis in vivo. RESULTS: We identified intrinsic endothelial HEY1 SUMOylation at conserved lysines by TRIM28 (tripartite motif containing 28) as the unique E3 ligase. Functionally, SUMOylation facilitated HEY1-mediated suppression of angiogenic RTK (receptor tyrosine kinase) signaling and angiogenesis in primary human endothelial cells and mice with endothelial cell-specific expression of wild-type HEY1 or a SUMOylation-deficient HEY1 mutant. Mechanistically, SUMOylation facilitates HEY1 homodimer formation, which in turn preserves HEY1's DNA-binding capability via recognition of E-box promoter elements. Therefore, SUMOylation maintains HEY1's function as a repressive TF controlling numerous angiogenic genes, including RTKs and Notch pathway components. Proangiogenic stimuli induce HEY1 deSUMOylation, leading to heterodimerization of HEY1 with HES (hairy and enhancer of split)-1, which results in ineffective DNA binding and loss of HEY1's angiogenesis-suppressive activity. CONCLUSIONS: Our findings demonstrate that reversible HEY1 SUMOylation is a molecular mechanism that coordinates endothelial angiogenic signaling and angiogenesis, both in physiological and pathological milieus, by fine-tuning the transcriptional activity of HEY1. Specifically, SUMOylation facilitates the formation of the HEY1 transcriptional complex and enhances its DNA-binding capability in endothelial cells.


Asunto(s)
Células Endoteliales , Sumoilación , Animales , Humanos , Ratones , Angiogénesis , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , ADN/metabolismo , Células Endoteliales/metabolismo
2.
PLoS Pathog ; 19(6): e1011420, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-37262073

RESUMEN

Enterovirus A71 (EV-A71) infection is a major cause of severe hand, foot and mouth disease (HFMD) in young children. The characteristics of EV-A71 neutralizing antibodies in HFMD patients are not well understood. In this study, we identified and cloned EV-A71-neutralizing antibodies by single cell RNA and B cell receptor sequencing of peripheral blood mononuclear cells. From 145 plasmablasts, we identified two IgG1 monoclonal antibodies (mAbs) and six IgM mAbs that neutralized EV-A71. Four of the IgM mAbs harbor germline variable sequences and neutralize EV-A71 potently. Two genetically similar IgM antibodies from two patients have recurrent heavy chain variable domain gene usage and similar complementarity-determining region 3 sequences. We mapped the residues of EV-A71 critical for neutralization through selection of virus variants resistant to antibody neutralization in the presence of neutralizing mAbs. The residues critical for neutralization are conserved among EV-A71 genotypes. Epitopes for the two genetically similar antibodies overlap with the SCARB2 binding site of EV-A71. We used escape variants to measure the epitope-specific antibody response in acute phase serum samples from EV-A71 infected HFMD patients. We found that these epitopes are immunogenic and contributed to the neutralizing antibody response against the virus. Our findings advance understanding of antibody response to EV-A71 infection in young children and have translational potential: the IgM mAbs could potentially be used for prevention or treatment of EV-A71 infections.


Asunto(s)
Enterovirus Humano A , Infecciones por Enterovirus , Enterovirus , Enfermedad de Boca, Mano y Pie , Niño , Humanos , Preescolar , Enterovirus/genética , Enterovirus Humano A/genética , Leucocitos Mononucleares , Anticuerpos Neutralizantes , Anticuerpos Antivirales , Epítopos , Inmunoglobulina M , Anticuerpos Monoclonales , Antígenos Virales/genética
3.
Anal Chem ; 96(18): 7194-7203, 2024 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-38656822

RESUMEN

To obtain enhanced physical and biological properties, various nanoparticles are typically assembled into hybrid nanoparticles through the binding of multiple homologous DNA strands to their complementary counterparts, commonly referred to as homomultivalent assembly. However, the poor binding affinity and limited controllability of homomultivalent disassembly restrict the assembly yield and dynamic functionality of the hybrid nanoparticles. To achieve a higher binding affinity and flexible assembly choice, we utilized the paired heteromultivalency DNA to construct hybrid nanoparticles and demonstrate their excellent assembly characteristics and dynamic applications. Specifically, through heteromultivalency, DNA-functionalized magnetic beads (MBs) and gold nanoparticles (AuNPs) were efficiently assembled. By utilizing ICP-MS, the assembly efficiency of AuNPs on MBs was directly monitored, enabling quantitative analysis and optimization of heteromultivalent binding events. As a result, the enhanced assembly yield is primarily attributed to the fact that heteromultivalency allows for the maximization of effective DNA probes on the surface of nanoparticles, eliminating steric hindrance interference. Subsequently, with external oligonucleotides as triggers, it was revealed that the disassembly mechanism of hybrid nanoparticles was initiated, which was based on an increased local concentration rather than toehold-mediated displacement of paired heteromultivalency DNA probes. Capitalizing on these features, an output platform was then established based on ICP-MS signals that several Boolean operations and analytical applications can be achieved by simply modifying the design sequences. The findings provide new insights into DNA biointerface interaction, with potential applications to complex logic operations and the construction of large DNA nanostructures.


Asunto(s)
ADN , Oro , Espectrometría de Masas , Nanopartículas del Metal , Oro/química , ADN/química , Nanopartículas del Metal/química
4.
Small ; 20(7): e2303502, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37840447

RESUMEN

Borophene, a promising material with potential applications in electronics, energy storage, and sensors, is successfully grown as a monolayer on Ag(111), Cu(111), and Au(111) surfaces using molecular beam epitaxy. The growth of two-dimensional borophene on Ag(111) and Au(111) is proposed to occur via surface adsorption and boron segregation, respectively. However, the growth mode of borophene on Cu(111) remains unclear. To elucidate this, scanning tunneling microscopy in conjunction with theoretical calculations is used to study the phase transformation of boron nanostructures under post-annealing treatments. Results show that by elevating the substrate temperature, boron nanostructures undergo an evolution from amorphous boron to striped-phase borophene (η = 1/6) adhering to the Cu ⟨ 1 1 ¯ 0 ⟩ $\langle {1\bar{1}0} \rangle $ step edge, and finally to irregularly shaped ß-type borophene (η = 5/36) either on the substrate surface or embedded in the topmost Cu layer. dI/dV spectra recorded near the borophene/Cu lateral interfaces indicate that the striped-phase borophene is a metastable phase, requiring more buckling and electron transfer to stabilize the crystal structure. These findings offer not only an in-depth comprehension of the ß-type borophene formation on Cu(111), but also hold potential for enabling borophene synthesis on weakly-binding semiconducting or insulating substrates with 1D active defects.

5.
J Stroke Cerebrovasc Dis ; 33(8): 107632, 2024 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-38417566

RESUMEN

BACKGROUND AND PURPOSE: Post-stroke cognitive impairment (PSCI) is a frequent consequence of stroke, which affects the quality of life and prognosis of stroke survivors. Numerous studies have indicated that blood biomarkers may be the key determinants for predicting and diagnosing cognitive impairment, but the results remain varied. Therefore, this meta-analysis aims to summarize potential biomarkers associated with PSCI. METHODS: PubMed, Web of Science, Embase, and Cochrane Library were comprehensively searched for studies exploring blood biomarkers associated with PSCI from inception to 15 April 2022. RESULTS: 63 studies were selected from 4,047 references, which involves 95 blood biomarkers associated with the PSCI. We meta-analyzed 20 potential blood biomarker candidates, the results shown that the homocysteine (Hcy) (SMD = 0.35; 95 %CI: 0.20-0.49; P < 0.00001), c-reactive protein (CRP) (SMD = 0.49; 95 %CI: 0.20-0.78; P = 0.0008), uric acid (UA) (SMD = 0.41; 95 %CI: 0.06-0.76; P = 0.02), interleukin 6 (IL-6) (SMD = 0.92; 95 % CI: 0.27-1.57; P = 0.005), cystatin C (Cys-C) (SMD = 0.58; 95 %CI: 0.28-0.87; P = 0.0001), creatinine (SMD = 0.39; 95 %CI: 0.23-0.55; P < 0.00001) and tumor necrosis factor alpha (TNF-α) (SMD = 0.45; 95 %CI: 0.08-0.82; P = 0.02) levels were significantly higher in patients with PSCI than in the non-PSCI group. CONCLUSION: Based on our findings, we recommend that paramedics focus on the blood biomarkers levels of Hcy, CRP, UA, IL-6, Cys-C, creatinine and TNF-α in conjunction with neuroimaging and neuropsychological assessment to assess the risk of PSCI, which may help with early detection and timely preventive measures. At the same time, other potential blood biomarkers should be further validated in future studies.

6.
Am J Physiol Cell Physiol ; 324(2): C407-C419, 2023 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-36534502

RESUMEN

Angiogenesis is involved in development, reproduction, wound healing, homeostasis, and other pathophysiological events. Imbalanced angiogenesis predisposes patients to various pathological processes, such as angiocardiopathy, inflammation, and tumorigenesis. MicroRNAs (miRNAs) have been found to be important in regulating cellular processing and physiological events including angiogenesis. However, the role of miRNAs that regulate angiogenesis (angiomiRs) is not fully understood. Here, we observed a downregulation of the miR-196 family in endothelial cells upon hypoxia. Functionally, miR-196b-5p inhibited the angiogenic functions of endothelial cells in vitro and suppressed angiogenesis in Matrigel plugs and skin wound healing in vivo. Mechanistically, miR-196b-5p bound onto the 3' untranslated region (UTR) of high-mobility group AT-hook 2 (HMGA2) mRNA and repressed the translation of HMGA2, which in turn represses HIF1α accumulation in endothelial cells upon hypoxia. Together, our results establish the role of endothelial miR-196b-5p as an angiomiR that negatively regulates endothelial growth in angiogenesis via the hypoxia/miR-196b-5p/HMGA2/HIF1α loop. miR-196b-5p and its regulatory loop could be an important addition to the molecular mechanisms underlying angiogenesis and may serve as potential targets for antiangiogenic therapy.


Asunto(s)
Células Endoteliales , Hipoxia , MicroARNs , Humanos , Línea Celular Tumoral , Proliferación Celular , Regulación hacia Abajo , Células Endoteliales/metabolismo , Hipoxia/metabolismo , MicroARNs/genética , MicroARNs/metabolismo , Neovascularización Patológica/metabolismo
7.
Opt Express ; 31(22): 35471-35483, 2023 Oct 23.
Artículo en Inglés | MEDLINE | ID: mdl-38017716

RESUMEN

We demonstrate the existence of surface gap solitons, a special type of asymmetric solitons, in the one-dimensional nonlinear Schrödinger equation with quintic nonlinearity and a periodic linear potential. The nonlinearity is suddenly switched in a step-like fashion in the middle of the transverse spatial region, while the periodic linear potential is chosen in the form of a simple sin 2 lattice. The asymmetric nonlinearities in this work can be realized by the Feshbach resonance in Bose-Einstein condensates or by the photorefractive effect in optics. The major peaks in the gap soliton families are asymmetric and they are located at the position of the jump in nonlinearity (at x = 0). In addition, the major peaks of the two-peak and multi-peak solitons at the position x = 0 are higher than those after that position, at x > 0. And such phenomena are more obvious when the value of chemical potential is large, or when the difference of nonlinearity values across the jump is big. Along the way, linear stability analysis of the surface gap solitons is performed and the stability domains are identified. It is found that in this model, the solitons in the first band gap are mostly stable (excepting narrow domains of instability at the edges of the gap), while those in the second band gap are mostly unstable (excepting extremely narrow domains of stability for fundamental solitons). These findings are also corroborated by direct numerical simulations.

8.
Proc Natl Acad Sci U S A ; 117(8): 3938-3943, 2020 02 25.
Artículo en Inglés | MEDLINE | ID: mdl-32047032

RESUMEN

Thin solids often develop elastic instabilities and subsequently complex, multiscale deformation patterns. Revealing the organizing principles of this spatial complexity has ramifications for our understanding of morphogenetic processes in plant leaves and animal epithelia and perhaps even the formation of human fingerprints. We elucidate a primary source of this morphological complexity-an incompatibility between an elastically favored "microstructure" of uniformly spaced wrinkles and a "macrostructure" imparted through the wrinkle director and dictated by confinement forces. Our theory is borne out of experiments and simulations of floating sheets subjected to radial stretching. By analyzing patterns of grossly radial wrinkles we find two sharply distinct morphologies: defect-free patterns with a fixed number of wrinkles and nonuniform spacing and patterns of uniformly spaced wrinkles separated by defect-rich buffer zones. We show how these morphological types reflect distinct minima of a Ginzburg-Landau functional-a coarse-grained version of the elastic energy, which penalizes nonuniform wrinkle spacing and amplitude, as well as deviations of the actual director from the axis imposed by confinement. Our results extend the effective description of wrinkle patterns as liquid crystals [H. Aharoni et al, Nat. Commun. 8, 15809 (2017)], and we highlight a fascinating analogy between the geometry-energy interplay that underlies the proliferation of defects in the mechanical equilibrium of confined sheets and in thermodynamic phases of superconductors and chiral liquid crystals.

9.
J Am Soc Nephrol ; 33(1): 238-252, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34732507

RESUMEN

BACKGROUND: Failure of the glomerular filtration barrier, primarily by loss of slit diaphragm architecture, underlies nephrotic syndrome in minimal change disease. The etiology remains unknown. The efficacy of B cell-targeted therapies in some patients, together with the known proteinuric effect of anti-nephrin antibodies in rodent models, prompted us to hypothesize that nephrin autoantibodies may be present in patients with minimal change disease. METHODS: We evaluated sera from patients with minimal change disease, enrolled in the Nephrotic Syndrome Study Network (NEPTUNE) cohort and from our own institutions, for circulating nephrin autoantibodies by indirect ELISA and by immunoprecipitation of full-length nephrin from human glomerular extract or a recombinant purified extracellular domain of human nephrin. We also evaluated renal biopsies from our institutions for podocyte-associated punctate IgG colocalizing with nephrin by immunofluorescence. RESULTS: In two independent patient cohorts, we identified circulating nephrin autoantibodies during active disease that were significantly reduced or absent during treatment response in a subset of patients with minimal change disease. We correlated the presence of these autoantibodies with podocyte-associated punctate IgG in renal biopsies from our institutions. We also identified a patient with steroid-dependent childhood minimal change disease that progressed to end stage kidney disease; she developed a massive post-transplant recurrence of proteinuria that was associated with high pretransplant circulating nephrin autoantibodies. CONCLUSIONS: Our discovery of nephrin autoantibodies in a subset of adults and children with minimal change disease aligns with published animal studies and provides further support for an autoimmune etiology. We propose a new molecular classification of nephrin autoantibody minimal change disease to serve as a framework for instigation of precision therapeutics for these patients.


Asunto(s)
Autoanticuerpos/sangre , Proteínas de la Membrana/inmunología , Nefrosis Lipoidea/sangre , Nefrosis Lipoidea/etiología , Adulto , Niño , Preescolar , Estudios de Cohortes , Femenino , Humanos , Masculino , Nefrosis Lipoidea/patología , Podocitos/patología
10.
Anal Chem ; 94(51): 17746-17750, 2022 12 27.
Artículo en Inglés | MEDLINE | ID: mdl-36480455

RESUMEN

DNA-based logic computing potentially for analysis of biomarker inputs and generation of oligonucleotide signal outputs is of great interest to scientists in diverse areas. However, its practical use for sensing of multiple biomarkers is limited by the universality and robustness. Based on a proximity assay, a lanthanide encoded logically gated micromachine (LGM-Ln) was constructed in this work, which is capable of responding to multiplex inputs in biological matrices. Under the logic function controls triggered by inputs and a Boolean "AND" algorithm, it is followed by an amplified "ON" signal to indicate the analytes (inputs). In this logically gated sensing system, the whole computational process does not involve strand displacement in an intermolecular reaction, and a threshold-free design is employed to generate the 0 and 1 computation via intraparticle cleavage, which facilitates the computation units and makes the "computed values" more reliable. By simply altering the affinity ligands for inputs' biorecognition, LGM-Ln can also be extended to multi-inputs mode and produce the robust lanthanide encoded outputs in the whole human serum for sensing nucleic acids (with the detection limit of 10 pM) and proteins (with the detection limit of 20 pM). Compared with a logically gated micromachine encoded with fluorophores, the LGM-Ln has higher resolution and no spectral overlaps for multiple inputs, thus holding great promise in multiplex analyses and clinical diagnosis.


Asunto(s)
Ácidos Nucleicos , Humanos , ADN/química , Oligonucleótidos , Colorantes Fluorescentes , Espectrometría de Masas
11.
Small ; 18(22): e2201449, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35557499

RESUMEN

Rechargeable aqueous proton batteries are promising competitors for the next generation of energy storage systems with the fast diffusion kinetics and wide availability of protons. However, poor cycling stability is a big challenge for proton batteries due to the attachment of water molecules to the electrode surface in acid electrolytes. Here, a hydrogen-bond disrupting electrolyte strategy to boost proton battery stability via simultaneously tuning the hydronium ion solvation sheath in the electrolyte and the electrode interface is reported. By mixing cryoprotectants such as glycerol with acids, hydrogen bonds involving water molecules are disrupted leading to a modified hydronium ion solvation sheaths and minimized water activity. Concomitantly, glycerol absorbs on the electrode surface and acts to protect the electrode surface from water. Fast and stable proton storage with high rate capability and long cycle life is thus achieved, even at temperatures as low as -50 °C. This electrolyte strategy may be universal and is likely to pave the way toward highly stable aqueous energy storage systems.


Asunto(s)
Glicerol , Protones , Electrólitos/química , Enlace de Hidrógeno , Agua/química
12.
Small ; 18(45): e2202992, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36156409

RESUMEN

Proton electrochemistry is promising for developing post-lithium energy storage devices with high capacity and rate capability. However, some electrode materials are vulnerable because of the co-intercalation of free water molecules in traditional acid electrolytes, resulting in rapid capacity fading. Here, the authors report a molecular crowding electrolyte with the usage of poly(ethylene glycol) (PEG) as a crowding agent, achieving fast and stable electrochemical proton storage and expanded working potential window (3.2 V). Spectroscopic characterisations reveal the formation of hydrogen bonds between water and PEG molecules, which is beneficial for confining the activity of water molecules. Molecular dynamics simulations confirm a significant decrease of free water fraction in the molecular crowding electrolyte. Dynamic structural evolution of the MoO3 anode is studied by in-situ synchrotron X-ray diffraction (XRD), revealing a reversible multi-step naked proton (de)intercalation mechanism. Surficial adsorption of PEG molecules on MoO3 anode works in synergy to alleviate the destructive effect of concurrent water desolvation, thereby achieving enhanced cycling stability. This strategy offers possibilities of practical applications of proton electrochemistry thanks to the low-cost and eco-friendly nature of PEG additives.


Asunto(s)
Suministros de Energía Eléctrica , Protones , Electrólitos/química , Litio/química , Agua
13.
Chembiochem ; 23(6): e202100548, 2022 03 18.
Artículo en Inglés | MEDLINE | ID: mdl-34989090

RESUMEN

Isothermal exponential amplification technology has rarely been fabricated as a universal sensing platform for the detection of proteins. To broaden their application, we have developed a strategy, named protein-recognition-initiated exponential amplification reaction (PRIEAR) using protein recognition to induce DNA assembly, which converts protein recognition events into ssDNA amplicons and combines two-stage amplification to achieve exponential amplification. Taking advantage of this principle, diverse biomarkers can be quantified at sub-picomolar concentrations in a homogenous manner, making PRIEAR suitable for clinical settings. Therefore, this strategy can expand the powerful isothermal exponential amplification technology to protein targets and thus provide a new toolbox in clinical and biomedical applications.


Asunto(s)
Técnicas Biosensibles , Técnicas de Amplificación de Ácido Nucleico , ADN , Proteínas
14.
J Transl Med ; 20(1): 530, 2022 11 18.
Artículo en Inglés | MEDLINE | ID: mdl-36401321

RESUMEN

BACKGROUND: Liver cancer is the fifth leading cause of cancer death worldwide, but early diagnosis and treatment of liver cancer remains a clinical challenge. How to screen and diagnose liver cancer early and prolong the survival rate is still the focus of researchers. METHODS: Cell experiments were used to detect the effect of WZ35 on the colony formation ability and proliferation activity of hepatoma cells, nude mouse experiment to observe the in vivo anticancer activity and toxic side effects of WZ35; metabolomics analysis, glucose metabolism experiment and Seahorse analysis of liver cancer cells treated with WZ35; cell experiments combined with bioinformatics analysis to explore the mechanism of WZ35-mediated metabolic reprogramming to exert anticancer activity; tissue microarray and case analysis to evaluate the clinical significance of biomarkers for early diagnosis, treatment and prognosis evaluation of liver cancer. RESULTS: WZ35 inhibited the proliferation activity of various cell lines of liver cancer, and showed good therapeutic effect in nude mice model of hepatocellular carcinoma without obvious toxic and side effects; WZ35 inhibited the absorption of glucose in hepatoma cells, and the drug effect glycolysis, phosphorylation and purine metabolism are relatively seriously damaged; WZ35 mainly inhibits YAP from entering the nucleus as a transcription factor activator by activating oxidative stress in liver cancer cells, reducing the transcription of GLUT1, and finally reducing its GLUT1. Tissue microarray and case analysis showed that GLUT1 and YAP were highly expressed and correlated in liver cancer patients, and were associated with poor patient prognosis. The GLUT1-YAP risk model had a high score in predicting prognosis. CONCLUSION: The study confirms that WZ35 is a small molecule glycolysis inhibitor, and through its properties, it mediates metabolic reprogramming dominated by impaired glycolysis, oxidative phosphorylation and purine metabolism to inhibit the proliferation activity of liver cancer cells. Our findings present novel insights into the pathology of liver cancer and potential targets for new therapeutic strategies. GLUT1-YAP has important reference significance for predicting the stages of disease progression in liver cancer patients and have the potential to serve as novel biomarkers for the diagnosis and treatment of liver cancer.


Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , Ratones , Animales , Carcinoma Hepatocelular/tratamiento farmacológico , Carcinoma Hepatocelular/metabolismo , Transportador de Glucosa de Tipo 1/metabolismo , Ratones Desnudos , Especies Reactivas de Oxígeno/metabolismo , Línea Celular Tumoral , Neoplasias Hepáticas/tratamiento farmacológico , Glucólisis , Purinas/uso terapéutico
15.
Phys Chem Chem Phys ; 24(27): 16415-16436, 2022 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-35766107

RESUMEN

In this contribution, we review models for the lattice effects in quantum dynamics calculations on surface scattering, which is important to modeling heterogeneous catalysis for achieving an interpretation of experimental measurements. Unlike dynamics models for reactions in the gas phase, those for heterogeneous reactions have to include the effects of the surface. For manageable computational costs in calculations, the effects of static surface (SS) are firstly modeled as this is simply and easily implemented. Then, the SS model has to be improved to include the effects of the flexible surface, that is the lattice effects. To do this, various surface models have been designed where the coordinates of the surface atoms are introduced in the Hamiltonian operator, especially those of the top surface atom. Based on this model Hamiltonian operator, extensive multi-dimension quantum dynamics calculations can be performed to recover the lattice effects. Here, we first review an overview of the techniques in constructing the Hamiltonian operator, which is a sum of the kinetic energy operator (KEO) and potential energy surface (PES). Since the PES containing the coordinates of the surface atoms in a cell is still expensive, the SS model is often accepted. We consider a mathematical model, called the coupled harmonic oscillator (CHO) model, to introduce the concepts of adiabatic and diabatic representations for separating the molecule and surface. Under the adiabatic model, we further introduce the expansion model where the potential function is Taylor expanded around the optimized geometry of the surface. By an expansion model truncated at the first and second order, various coupling surface models between the molecule and surface are derived. Moreover, by further and deeply understanding the adiabatic representation, an effective Hamiltonian operator is obtained by optimizing the total wave function in factorized form. By this factorized form of wave function and effective Hamiltonian operator, the geometry phase of the surface wave function is theoretically found. This theoretical prediction may be measured by carefully designing experiments. Finally, discussions on the adiabatic representation, the PES construction, and possibility of the classical-dynamics solutions are given. Based on these discussions, a simple outlook on the dynamics of photocatalytics is finally given.

16.
Molecules ; 28(1)2022 Dec 26.
Artículo en Inglés | MEDLINE | ID: mdl-36615394

RESUMEN

The advent of graphene opens up the research into two-dimensional (2D) materials, which are considered revolutionary materials. Due to its unique geometric structure, graphene exhibits a series of exotic physical and chemical properties. In addition, single-element-based 2D materials (Xenes) have garnered tremendous interest. At present, 16 kinds of Xenes (silicene, borophene, germanene, phosphorene, tellurene, etc.) have been explored, mainly distributed in the third, fourth, fifth, and sixth main groups. The current methods to prepare monolayers or few-layer 2D materials include epitaxy growth, mechanical exfoliation, and liquid phase exfoliation. Although two Xenes (aluminene and indiene) have not been synthesized due to the limitations of synthetic methods and the stability of Xenes, other Xenes have been successfully created via elaborate artificial design and synthesis. Focusing on elemental 2D materials, this review mainly summarizes the recently reported work about tuning the electronic, optical, mechanical, and chemical properties of Xenes via surface modifications, achieved using controllable approaches (doping, adsorption, strain, intercalation, phase transition, etc.) to broaden their applications in various fields, including spintronics, electronics, optoelectronics, superconducting, photovoltaics, sensors, catalysis, and biomedicines. These advances in the surface modification of Xenes have laid a theoretical and experimental foundation for the development of 2D materials and their practical applications in diverse fields.

17.
Anal Chem ; 93(37): 12602-12608, 2021 09 21.
Artículo en Inglés | MEDLINE | ID: mdl-34506121

RESUMEN

MicroRNAs (miRNAs) play key roles in biological processes in plants, such as stress resistance, yet can hardly be quantified by an enzyme-involved terminal polymerization process due to their 2'-O-methyl modifications at the 3'-terminal. Herein, we proposed a CRISPR/Cas14a-based rolling circle amplification (termed Cas14R) assay, allowing reverse transcription-free and demethylation-free detection of plant miRNAs with single-nucleotide resolution. The employment of target-templated rolling circle amplification circumvents the extension of the unaccessible 2'-O-methyl group at the 3'-terminal. Particularly, the activated Cas14a confers the trans-cleavage activity for identifying target single-stranded DNA sequences without the necessity of the protospacer adjacent motif, generalizing the detection of miRNA sequences and the integration of different isothermal amplification techniques. Ultimately, the Cas14R assay has been applied to profile miR156a to evaluate the ripeness process of banana, indicating its feasibility in analyzing the roles of miRNAs in biological processes of plants.


Asunto(s)
MicroARNs , Bioensayo , Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas , MicroARNs/genética , Técnicas de Amplificación de Ácido Nucleico
18.
Anal Chem ; 93(7): 3393-3402, 2021 02 23.
Artículo en Inglés | MEDLINE | ID: mdl-33511840

RESUMEN

The outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused a global health emergency, and its gene mutation and evolution further posed uncertainty of epidemic risk. Herein, we reported a light-up CRISPR-Cas13 transcription amplification method, which enables the detection of SARS-CoV-2 and its mutated variants. Sequence specificity was ensured by both the ligation process and Cas13a/crRNA recognition, allowing us to identify viral RNA mutation. Light-up RNA aptamer allows sensitive output of amplification signals via target-activated ribonuclease activity of CRISPR-Cas13a. The RNA virus assay has been designed to detect coronavirus, SARS-CoV-2, Middle East respiratory syndrome (MERS), and SARS, as well as the influenza viruses such as, H1N1, H7N9, and H9N2. It was accommodated to sense as low as 82 copies of SARS-CoV-2. Particularly, it allowed us to strictly discriminate key mutation of the SARS-CoV-2 variant, D614G, which may induce higher epidemic and pathogenetic risk. The proposed RNA virus assays are promising for point-of-care monitoring of SARS-CoV-2 and its risking variants.


Asunto(s)
Prueba de Ácido Nucleico para COVID-19/métodos , COVID-19/virología , Proteínas Asociadas a CRISPR/genética , Sistemas CRISPR-Cas/genética , Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas/genética , SARS-CoV-2/aislamiento & purificación , Humanos , Técnicas de Diagnóstico Molecular , Mutación , Técnicas de Amplificación de Ácido Nucleico , ARN Viral/genética , SARS-CoV-2/genética
19.
Small ; 17(40): e2102375, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34499420

RESUMEN

Proton is an ideal charge carrier for rechargeable batteries due to its small ionic radius, ultrafast diffusion kinetics and wide availability. However, in commonly used acid electrolytes, the co-interaction of polarized water and proton (namely hydronium) with electrode materials often causes electrode structural distortions. The hydronium adsorption on electrode surfaces also facilitates hydrogen evolution as an unwanted side reaction. Here, a "water-in-sugar" electrolyte with high concentration of glucose dissolved in acid to enable the naked proton intercalation, as well as an extended 3.9 V working potential window, is shown. A glucose-derived organic thin film is formed on electrode surface upon cycling. Molecular dynamics simulations reveal the significant decrease of free water in bulk electrolytes, while density functional theory calculations indicate that glucose preferentially binds to the electrode surface which can inhibit water adsorption. The scarcity of free water and the protective organic film work in synergy to suppress water interactions with the electrode surface, which enables the naked proton (de)intercalation. The "water-in-sugar" electrolyte significantly enhances a MoO3 electrode for stable cycling over 100 000 times. This facile electrolyte approach opens new avenues to aqueous electrochemistry and energy storage devices.


Asunto(s)
Protones , Agua , Suministros de Energía Eléctrica , Electrólitos , Azúcares
20.
J Virol ; 94(11)2020 05 18.
Artículo en Inglés | MEDLINE | ID: mdl-32188736

RESUMEN

Hepatitis B virus (HBV) chronically infects approximately 350 million people worldwide, and 600,000 deaths are caused by HBV-related hepatic failure, liver cirrhosis, and hepatocellular carcinoma annually. It is important to reveal the mechanism underlying the regulation of HBV replication. This study demonstrated that osteopetrosis-associated transmembrane protein 1 (Ostm1) plays an inhibitory role in HBV replication. Ostm1 represses the levels of HBeAg and HBsAg proteins, HBV 3.5-kb and 2.4/2.1-kb RNAs, and core-associated DNA in HepG2, Huh7, and NTCP-HepG2 cells. Notably, Ostm1 has no direct effect on the activity of HBV promoters or the transcription of HBV RNAs; instead, Ostm1 binds to HBV RNA to facilitate RNA decay. Detailed studies further demonstrated that Ostm1 binds to and recruits the RNA exosome complex to promote the degradation of HBV RNAs, and knockdown of the RNA exosome component exonuclease 3 (Exosc3) leads to the elimination of Ostm1-mediated repression of HBV replication. Mutant analyses revealed that the N-terminal domain, the transmembrane domain, and the C-terminal domain are responsible for the repression of HBV replication, and the C-terminal domain is required for interaction with the RNA exosome complex. Moreover, Ostm1 production is not regulated by interferon-α (IFN-α) or IFN-γ, and the expression of IFN signaling components is not affected by Ostm1, suggesting that Ostm1 anti-HBV activity is independent of the IFN signaling pathway. In conclusion, this study revealed a distinct mechanism underlying the repression of HBV replication, in which Ostm1 binds to HBV RNA and recruits RNA exosomes to degrade viral RNA, thereby restricting HBV replication.IMPORTANCE Hepatitis B virus (HBV) is a human pathogen infecting the liver to cause a variety of diseases ranging from acute hepatitis to advanced liver diseases, fulminate hepatitis, liver cirrhosis, and hepatocellular carcinoma, thereby causing a major health problem worldwide. In this study, we demonstrated that Ostm1 plays an inhibitory role in HBV protein production, RNA expression, and DNA replication. However, Ostm1 has no effect on the activities of the four HBV promoters; instead, it binds to HBV RNA and recruits RNA exosomes to promote HBV RNA degradation. We further demonstrated that the anti-HBV activity of Ostm1 is independent of the interferon signaling pathway. In conclusion, this study reveals a distinct mechanism underlying the repression of HBV replication and suggests that Ostm1 is a potential therapeutic agent for HBV infection.


Asunto(s)
Exosomas/metabolismo , Virus de la Hepatitis B/fisiología , Proteínas de la Membrana/metabolismo , ARN Viral/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Replicación Viral , Complejo Multienzimático de Ribonucleasas del Exosoma/genética , Complejo Multienzimático de Ribonucleasas del Exosoma/metabolismo , Exosomas/genética , Exosomas/virología , Técnicas de Silenciamiento del Gen , Células HEK293 , Células HeLa , Células Hep G2 , Antígenos de Superficie de la Hepatitis B/genética , Antígenos de Superficie de la Hepatitis B/metabolismo , Antígenos e de la Hepatitis B/genética , Antígenos e de la Hepatitis B/metabolismo , Humanos , Interferón-alfa/genética , Interferón-alfa/metabolismo , Interferón gamma/genética , Interferón gamma/metabolismo , Proteínas de la Membrana/genética , Dominios Proteicos , ARN Viral/genética , Proteínas de Unión al ARN/genética , Proteínas de Unión al ARN/metabolismo , Ubiquitina-Proteína Ligasas/genética
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