ACS Macro Lett
November 2024
The mesoscope has emerged as a powerful imaging tool in biomedical research, yet its high cost and low resolution have limited its broader application. Here, we introduce the Omni-Mesoscope, a high-spatial-temporal and multimodal mesoscopic imaging platform built from cost-efficient off-the-shelf components. This system uniquely merges the capabilities of label-free quantitative phase microscopy to capture live-cell morphodynamics across thousands of cells with highly multiplexed fluorescence imaging for comprehensive molecular characterization.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
October 2024
Using angle-resolved X-ray photoelectron spectroscopy, sum-frequency generation vibrational spectroscopy, contact angle measurements, and molecular dynamics simulations, we verify that the glass transition temperature () of polymer glass is lower near the free surface. However, the experimental -gradients showed a linear variation with depth () from the free surface, while the simulated equilibrium -gradients exhibited a double exponential -dependence. In typical simulations, is determined based on the relaxation time of the system reaching a prescribed threshold value at equilibrium.
View Article and Find Full Text PDFThe mesoscope has emerged as a powerful imaging tool in biomedical research, yet its high cost and low resolution have limited its broader application. Here, we introduce the Omni-Mesoscope, a cost-effective high-spatial-temporal, multimodal, and multiplex mesoscopic imaging platform built from cost-efficient off-the-shelf components. This system uniquely merges the capabilities of quantitative phase microscopy to capture live-cell dynamics over a large cell population with highly multiplexed fluorescence imaging for comprehensive molecular characterization.
View Article and Find Full Text PDFT lymphocyte activation plays a pivotal role in adaptive immune response and alters the spatial organization of nuclear architecture that subsequently impacts transcription activities. Here, using stochastic optical reconstruction microscopy (STORM), we observe dramatic de-condensation of chromatin and the disruption of nuclear envelope at a nanoscale resolution upon T lymphocyte activation. Super-resolution imaging reveals that such alterations in nuclear architecture are accompanied by the release of nuclear DNA into the cytoplasm, correlating with the degree of chromatin decompaction within the nucleus.
View Article and Find Full Text PDFEcotoxicol Environ Saf
March 2024
The potential of invertebrates in the biodegradation of plastic polymers such as polyvinyl chloride (PVC) is receiving increasing attention. The present study is aimed to identify the gut microbiome involved in this degradation in yellow mealworms, i.e.
View Article and Find Full Text PDFThe polymer/substrate interface plays a significant role in the dynamics of nanoconfined polymers because of its suppression on polymer mobility and its long-range propagation feature, while the molecular origin of the long-range substrate effect in unentangled polymer material is still ambiguous. Herein, we investigated the propagation distances of the substrate effect (*) by a fluorinated tracer-labeled method of two unentangled polymer films supported on silicon substrates: linear and ring poly(methyl methacrylate) films with relatively low molecular weights. The results indicate that the value of * has a molecular weight dependence of *∝ ( is the degree of polymerization) in the unentangled polymer films, while *∝ was presented as previously reported in the entangled films.
View Article and Find Full Text PDFHerein, the adsorption of polystyrene (PS) on phenyl-modified SiO-Si substrates was investigated. Different from those for PS adsorption on a neat SiO-Si substrate, the growth rate () in the linear regime and / (, thickness of flattened and loosely adsorbed layers on the substrate; , radius of gyration) declined with increasing molecular weight () of PS and the phenyl content on the modified substrates, while the thickness of the flattened layer () and its coverage increased with increasing phenyl content. The results indicated that the adsorption of loose chains was controlled by the adsorption of flattened chains, as it only occurred in the empty contact sites remaining after the adsorption of flattened chains.
View Article and Find Full Text PDFHerein, the desorption of the adsorbed chains (including two regions of flattened chains and loosely adsorbed chains) was examined by monitoring the chain exchange kinetics between the adsorbed chains and the top-free chains in a bilayer system by using fluorine-labeled polystyrene (PS). The results indicated that the exchange behavior of PS-flattened chains with the top-free chains is much slower than that of PS-loose chains and has a strong molecular weight (MW) dependence. Interestingly, in the presence of loosely adsorbed chains, the desorption of flattened chains was accelerated greatly and had weaker MW dependency.
View Article and Find Full Text PDFThe amyloid precursor protein (APP) is linked to the genetics and pathogenesis of Alzheimer's disease (AD). It is the parent protein of the β-amyloid (Aβ) peptide, the main constituent of the amyloid plaques found in an AD brain. The pathways from APP to Aβ are intensively studied, yet the normal functions of APP itself have generated less interest.
View Article and Find Full Text PDFDue to the importance of the interface in the segmental dynamics of supported macromolecule ultrathin films, the glass transition temperature () of polystyrene (PS) ultrathin films upon solid substrates modified with a cross-linked PS (CLPS) layer has been investigated. The results showed that the of the thin PS films on a silica surface with a ∼5 nm cross-linked layer increased with reducing film thickness. Meanwhile, the increase in of the thin PS films became more pronounced with increasing the cross-linking density of the layer.
View Article and Find Full Text PDFImaging chromatin organization at the molecular-scale resolution remains an important endeavor in basic and translational research. Stochastic optical reconstruction microscopy (STORM) is a powerful superresolution imaging technique to visualize nanoscale molecular organization down to the resolution of ~20 to 30 nm. Despite the substantial progress in imaging chromatin organization in cells and model systems, its routine application on assessing pathological tissue remains limited.
View Article and Find Full Text PDFThalidomide induces γ-globin expression in erythroid progenitor cells, but its efficacy on patients with transfusion-dependent β-thalassemia (TDT) remains unclear. In this phase 2, multi-center, randomized, double-blind clinical trial, we aimed to determine the safety and efficacy of thalidomide in TDT patients. A hundred patients of 14 years or older were randomly assigned to receive placebo or thalidomide for 12 weeks, followed by an extension phase of at least 36 weeks.
View Article and Find Full Text PDFSuper-resolution localization microscopy allows visualization of biological structure at nanoscale resolution. However, the presence of heterogeneous background can degrade the nanoscale resolution by tens of nanometers and introduce significant image artifacts. Here we investigate and validate an efficient approach, referred to as extreme value-based emitter recovery (EVER), to accurately recover the distorted fluorescent emitters from heterogeneous background.
View Article and Find Full Text PDFChromatin organization play a vital role in gene regulation and genome maintenance in normal biological processes and in response to environmental insults. Disruption of chromatin organization imposes a significant effect on many cellular processes and is often associated with a range of pathological processes such as aging and cancer. Extensive attention has been attracted to understand the structural and functional studies of chromatin architecture.
View Article and Find Full Text PDFThe antibody immune response is essential for the survival of mammals. However, we still lack a systematic understanding of the antibody repertoire. Here, we developed a proteomic strategy to survey, at an unprecedented scale, the landscape of antigen-engaged, circulating camelid heavy-chain antibodies, whose minimal binding fragments are called VH antibodies or nanobodies.
View Article and Find Full Text PDFDirect visualization of higher-order chromatin structure at the molecular scale is of great importance for understanding the impact of chromatin organization on gene expression in many biological processes. Understanding the changes in chromatin structure during pathological processes requires the use of in vivo models and clinical samples, and formalin-fixed, paraffin-embedded (FFPE) tissue is the most widespread form of preservation. Here we describe the details of PathSTORM, an optimized stochastic optical reconstruction microscopy (STORM) protocol for high-quality super-resolution imaging of densely packed higher-order chromatin organization in pathological tissue.
View Article and Find Full Text PDFGenomic DNA is folded into a higher-order structure that regulates transcription and maintains genomic stability. Although progress has been made on understanding biochemical characteristics of epigenetic modifications in cancer, the in-situ higher-order folding of chromatin structure during malignant transformation remains largely unknown. Here, using optimized stochastic optical reconstruction microscopy (STORM) for pathological tissue (PathSTORM), we uncover a gradual decompaction and fragmentation of higher-order chromatin folding throughout all stages of carcinogenesis in multiple tumor types, and prior to tumor formation.
View Article and Find Full Text PDFA method based on the PeakForce QNM atomic force microscopic (AFM) adhesion measurement is employed to investigate the glassy dynamics of polystyrene (PS) single-chain particles end-grafted to SiO-Si substrates with different diameters, D, of 3.4 nm-8.8 nm and molar masses, M, of 8-123 kg/mol.
View Article and Find Full Text PDFWe observe that the confinement effect of polymer films can saturate with polymer-substrate interaction. Thickness dependences of the glass transition temperature, (), of random copolymer films of 4--butylstyrene (TBS) and 4-acetoxystyrene (AS) supported by silica (SiOx) were measured for different TBS concentrations, . For 0 ≤ ≤ 0.
View Article and Find Full Text PDFGenomic DNA in eukaryotic cells is tightly compacted with histone proteins into nucleosomes, which are further packaged into the higher-order chromatin structure. The physical structuring of chromatin is highly dynamic and regulated by a large number of epigenetic modifications in response to various environmental exposures, both in normal development and pathological processes such as aging and cancer. Higher-order chromatin structure has been indirectly inferred by conventional bulk biochemical assays on cell populations, which do not allow direct visualization of the spatial information of epigenomics (referred to as spatial epigenomics).
View Article and Find Full Text PDFHigh-throughput nanoscopy becomes increasingly important for unraveling complex biological processes from a large heterogeneous cell population at a nanoscale resolution. High-density emitter localization combined with a large field of view and fast imaging frame rate is commonly used to achieve a high imaging throughput, but the image processing speed and the presence of heterogeneous background in the dense emitter scenario remain a bottleneck. Here, we present a simple non-iterative approach, referred to as WindSTORM, to achieve high-speed high-density emitter localization with robust performance for various image characteristics.
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