Under hypoxic conditions in tumor cells, HIF-1α is unable to bind to VHL E3 ligase due to the blocked hydroxylation reaction, resulting in impaired degradation and intracellular accumulation. Mounting evidences show a close association between HIF-1α overexpression and drug resistance, treatment failure, and increased mortality. To address HIF-1α overexpression, we innovatively introduced an E3 ligase ligand to the HIF-1α inhibitor IDF-11774 using the PROTACs strategy, aiming to reactivate the degradative pathway impeded under hypoxia, and thereby achieve the degradation of HIF-1α protein under hypoxia.
View Article and Find Full Text PDFNanomaterials (Basel)
September 2024
Singlet fission (SF), as an effective way to break through the Shockley-Queisser limit, can dramatically improve energy conversion efficiency in solar cell areas. The formation, separation, and relaxation of triplet-pair excitons directly affect the triplet yield, especially triplet-pair separation; thus, how to enhance the triplet-pair separation rate becomes one of the key points to improve SF efficiency; the decay mechanism where the singlet state is converted into two triplet states is significant for the study of the SF mechanism. Herein, we employ ultrafast transient absorption spectroscopy to study the singlet-fission process of nano-amorphous 6, 13-bis(triisopropylsilylethynyl)-Pentacene (TIPS-pentacene) films in a diamond anvil cell (DAC).
View Article and Find Full Text PDFIn the presence of a high magnetic field, quantum Hall systems usually host both even- and odd-integer quantized states because of lifted band degeneracies. Selective control of these quantized states is challenging but essential to understand the exotic ground states and manipulate the spin textures. Here we demonstrate the quantum Hall effect in BiOSe thin films.
View Article and Find Full Text PDFStatistical copolymers have been extensively used in chemical industries and our daily lives, owing to their ease of synthesis and functionalization. However, self-assembly based on statistical copolymers has been haunted by high interfacial energy, poor stability, and low concentration. We proposed the statistical copolymerization-induced self-assembly (-PISA) as a general strategy for one-step preparing stable statistical copolymer assemblies with high solids content.
View Article and Find Full Text PDFThe pursuit of high-performance electronic devices has driven the research focus toward 2D semiconductors with high electron mobility and suitable band gaps. Previous studies have demonstrated that quasi-2D BiOSe (BOSe) has remarkable physical properties and is a promising candidate for further exploration. Building upon this foundation, the present work introduces a novel concept for achieving nonvolatile and reversible control of BOSe's electronic properties.
View Article and Find Full Text PDFNon-trivial topological structures, such as vortex-antivortex (V-AV) pairs, have garnered significant attention in the field of condensed matter physics. However, the detailed topological phase transition dynamics of V-AV pairs, encompassing behaviors like self-annihilation, motion, and dissociation, have remained elusive in real space. Here, polar V-AV pairs are employed as a model system, and their transition pathways are tracked with atomic-scale resolution, facilitated by in situ (scanning) transmission electron microscopy and phase field simulations.
View Article and Find Full Text PDFIn single unit-cell FeSe grown on SrTiO, the superconductivity transition temperature features a significant enhancement. Local phonon modes at the interface associated with electron-phonon coupling may play an important role in the interface-induced enhancement. However, such phonon modes have eluded direct experimental observations.
View Article and Find Full Text PDFIntroduction: Safety is one of the critical and persistent challenges in the construction industry. Measuring safety performance could allow decision-makers to check safety production processes and enhance the health and safety environment.
Method: This study developed a total-factor framework based on the global Data Envelopment Analysis (DEA) method to measure safety performance.
The presence of surface trap states (STSs) is one of the key factors to affect the electronic and optical properties of quantum dots (QDs), however, the exact mechanism of how STSs influence QDs remains unclear. Herein, we demonstrated the impact of STSs on electron transfer in CdSe QDs and triplet-triplet energy transfer (TTET) from CdSe to surface acceptor using femtosecond transient absorption spectroscopy. Three types of colloidal CdSe QDs, each containing various degrees of STSs as evidenced by photoluminescence and X-ray photoelectron spectroscopy, were employed.
View Article and Find Full Text PDFDielectric capacitors are highly desired in modern electronic devices and power systems to store and recycle electric energy. However, achieving simultaneous high energy density and efficiency remains a challenge. Here, guided by theoretical and phase-field simulations, we are able to achieve a superior comprehensive property of ultrahigh efficiency of 90-94% and high energy density of 85-90 J cm remarkably in strontium titanate (SrTiO), a linear dielectric of a simple chemical composition, by manipulating local symmetry breaking through introducing Ti/O defects.
View Article and Find Full Text PDFThe intricate nature of the surface structure of carbon dots (CDs) hinders a comprehensive understanding of their emission behavior. In this study, we employ two types of CDs created through acid-alkali treatments, one with surface protonation and the other with surface deprotonation, with the objective of investigating the impact of these surface modifications on carrier behavior using ultrafast spectroscopy techniques. TEM, XRD, FTIR and Raman spectra demonstrate the CDs' structure, featuring graphitic core and abundant surface functional groups.
View Article and Find Full Text PDFConventional indirect X-ray detectors employ scintillating phosphors to convert X-ray photons into photodiode-detectable visible photons, leading to low conversion efficiencies, low spatial resolutions, and optical crosstalk. Consequently, X-ray detectors that directly convert photons into electric signals have long been desired for high-performance medical imaging and industrial inspection. Although emerging hybrid inorganic-organic halide perovskites, such as CH NH PbI and CH NH PbBr , exhibit high sensitivity, they have salient drawbacks including structural instability, ion motion, and the use of toxic Pb.
View Article and Find Full Text PDFA high configurational entropy, achieved through a proper design of compositions, can minimize the Gibbs free energy and stabilize the quasi-equilibrium phases in a solid-solution form. This leads to the development of high-entropy materials with unique structural characteristics and excellent performance, which otherwise could not be achieved through conventional pathways. This work develops a high-entropy nonlinear dielectric system, based on the expansion of lead magnesium niobate-lead titanate.
View Article and Find Full Text PDFThe bis-benzimidazole derivative (BBM) molecule, consisting of two 2-(2'-hydroxyphenyl) benzimidazole (HBI) halves, has been synthesized and successfully utilized as a ratiometric fluorescence sensor for the sensitive detection of Cu based on enol-keto excited-state intramolecular proton transfer (ESIPT). In this study, we strategically implement femtosecond stimulated Raman spectroscopy and several time-resolved electronic spectroscopies, aided by quantum chemical calculations to investigate the detailed primary photodynamics of the BBM molecule. The results demonstrate that the ESIPT from BBM-enol* to BBM-keto* was observed in only one of the HBI halves with a time constant of 300 fs; after that, the rotation of the dihedral angle between the two HBI halves generated a planarized BBM-keto* isomer in 3 ps, leading to a dynamic redshift of BBM-keto* emission.
View Article and Find Full Text PDFPlasmonic nanoparticles (NP) possess great potential in photothermal therapy and diagnostics. However, novel NP require a detailed examination for potential toxicity and peculiarities of interaction with cells. Red blood cells (RBC) are important for NP distribution and the development of hybrid RBC-NP delivery systems.
View Article and Find Full Text PDFFront Cell Infect Microbiol
March 2023
Background: Recent studies reported the association between the changes in gut microbiota and sepsis, but there is unclear for the gut microbes on aged sepsis is associated acute lung injury (SALI), and metformin treatment for the change in gut microbiota. This study aimed to investigate the effect of metformin on gut microbiota and SALI in aged rats with sepsis. It also explored the therapeutic mechanism and the effect of metformin on aged rats with SALI.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
March 2023
Misfit dislocations at a heteroepitaxial interface produce huge strain and, thus, have a significant impact on the properties of the interface. Here, we use scanning transmission electron microscopy to demonstrate a quantitative unit-cell-by-unit-cell mapping of the lattice parameters and octahedral rotations around misfit dislocations at the BiFeO/SrRuO interface. We find that huge strain field is achieved near dislocations, i.
View Article and Find Full Text PDFThe scaling of silicon-based transistors at sub-ten-nanometre technology nodes faces challenges such as interface imperfection and gate current leakage for an ultrathin silicon channel. For next-generation nanoelectronics, high-mobility two-dimensional (2D) layered semiconductors with an atomic thickness and dangling-bond-free surfaces are expected as channel materials to achieve smaller channel sizes, less interfacial scattering and more efficient gate-field penetration. However, further progress towards 2D electronics is hindered by factors such as the lack of a high dielectric constant (κ) dielectric with an atomically flat and dangling-bond-free surface.
View Article and Find Full Text PDFPhototherapy is an efficient and safe way to reduce high levels of free 4,15-bilirubin (ZZ-BR) in the serum of newborns. The success of BR phototherapy lies in photoinduced configurational and structural isomerization processes that form excretable isomers. However, the physical picture of photoinduced photoisomerization of ZZ-BR is still unclear.
View Article and Find Full Text PDFOrganic-inorganic perovskite solar cells (PSCs) have achieved great attention due to their expressive power conversion efficiency (PCE) up to 25.7%. To improve the photovoltaic performance of PSCs, interface engineering between the perovskite and hole transport layer (HTL) is a widely used strategy.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2023
Large Stokes shift (LSS) red fluorescent proteins (RFPs) are highly desirable for bioimaging advances. The RFP mKeima, with coexisting cis- and trans-isomers, holds significance as an archetypal system for LSS emission due to excited-state proton transfer (ESPT), yet the mechanisms remain elusive. We implemented femtosecond stimulated Raman spectroscopy (FSRS) and various time-resolved electronic spectroscopies, aided by quantum calculations, to dissect the cis- and trans-mKeima photocycle from ESPT, isomerization, to ground-state proton transfer in solution.
View Article and Find Full Text PDFRecently various topological polar structures have been discovered in oxide thin films. Despite the increasing evidence of their switchability under electrical and/or mechanical fields, the dynamic property of isolated ones, which is usually required for applications such as data storage, is still absent. Here, we show the controlled nucleation and motion of isolated three-fold vertices under an applied electric field.
View Article and Find Full Text PDFRoom-temperature polar skyrmions, which have been recently discovered in oxide superlattice, have received considerable attention for their potential applications in nanoelectronics owing to their nanometer size, emergent chirality, and negative capacitance. For practical applications, their manipulation using external stimuli is a prerequisite. Herein, we study the dynamics of individual polar skyrmions at the nanoscale via in situ scanning transmission electron microscopy.
View Article and Find Full Text PDFBackground: Whether the decline of hepatitis B virus (HBV) RNA was associated with antiviral efficacy in chronic hepatitis B (CHB) patients receiving long-term nucleos(t)ide analogues (NAs) therapy remains unclear. We observed the levels of serum HBV RNA in CHB patients treated with entecavir (ETV) for 10 years and explored the clinical significance of HBV RNA during long-term antiviral treatment.
Methods: A total of 33 hepatitis B surface antigen (HBsAg)-positive CHB patients treated with ETV for up to 10 years were recruited for this study.
Heteroepitaxy with large lattice mismatch remains a great challenge for high-quality epifilm growth. Although great efforts have been devoted to epifilm growth with an in-plane lattice mismatch, the epitaxy of 2D layered crystals on stepped substrates with a giant out-of-plane lattice mismatch is seldom reported. Here, taking the molecular-beam epitaxy of 2D semiconducting Bi O Se on 3D SrTiO substrates as an example, a step-climbing epitaxy growth strategy is proposed, in which the n-th (n = 1, 2, 3…) epilayer climbs the step with height difference from out-of-plane lattice mismatch and continues to grow the n+1-th epilayer.
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