Super-resolution imaging of T lymphocyte activation reveals chromatin decondensation and disrupted nuclear envelope.

T 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. The authors show that under the influence of metabolism, T lymphocyte activation de-condenses chromatin, disrupts the nuclear envelope, and releases DNA into the cytoplasm. Taken together, this result provides a direct, molecular-scale insight into the alteration in nuclear architecture. It suggests the release of nuclear DNA into the cytoplasm as a general consequence of chromatin decompaction after lymphocyte activation.

Toward drift-free high-throughput nanoscopy through adaptive intersection maximization.

Single-molecule localization microscopy (SMLM) often suffers from suboptimal resolution due to imperfect drift correction. Existing marker-free drift correction algorithms often struggle to reliably track high-frequency drift and lack the computational efficiency to manage large, high-throughput localization datasets. We present an adaptive intersection maximization-based method (AIM) that leverages the entire dataset's information content to minimize drift correction errors, particularly addressing high-frequency drift, thereby enhancing the resolution of existing SMLM systems. We demonstrate that AIM can robustly and efficiently achieve an angstrom-level tracking precision for high-throughput SMLM datasets under various imaging conditions, resulting in an optimal resolution in simulated and biological experimental datasets. We offer AIM as one simple, model-free software for instant resolution enhancement with standard CPU devices.

Study of Mechanics and Durability of Non-Spontaneous Combustion Coal Gangue Coarse-Aggregate High-Performance Concrete.

The coal gangue coarse-aggregate content in ordinary concrete should not be too large. In order to further improve the utilization rate of coal gangue coarse aggregate, this study used the principle of "strong wrapped weak" to prepare high-performance concrete. This study considered four factors, namely, water-binder (W/B) ratios, non-spontaneous combustion coal gangue (NCCG) coarse-aggregate contents, fly ash-slag mass ratios, and silica fume coating to prepare high-performance concrete. The workability, mechanical, and durability properties were studied, and the changes in the interfacial transition zone (ITZ) of concrete before and after sulfate attack and freeze-thaw cycles were analyzed based on the SEM test. The life prediction of NCCG coarse-aggregate high-performance concrete was carried out based on the grey system GM(1,1) prediction model. The results show that the NCCG coarse-aggregate contents have the greatest effect on compressive strength, sulfate resistance, and frost resistance. The W/B ratio has the greatest effect on the anti-carbonization properties. Fly ash-slag mixing can obtain better durability. Considering the effect on the design service life of high-performance concrete, NCCG coarse aggregate is used to prepare high-performance concrete in North China, and the recommended content is 60%; in the Northwest and Northeast regions, the recommended content is 45%. This study provides a basis for the preparation of high-performance concrete with NCCG coarse aggregate.

Biodegradability enhancement of waste lubricating oil regeneration wastewater using electrocoagulation pretreatment.

As a sustainable management of fossil fuel resources and ecological environment protection, recycling used lubricating oil has received widespread attention. However, large amounts of waste lubricating-oil regeneration wastewater (WLORW) are inevitably produced in the recycling process, and challenges are faced by traditional biological treatment of WLORW. Thus, this study investigated the effectiveness of electrocoagulation (EC) as pretreatment and its removal mechanism. The electrolysis parameters (current density, initial pH, and inter-electrode distance) were considered, and maximal 60.06% of oil removal was achieved at a current density of 15 mA/cm2, initial pH of 7, and an inter-electrode distance of 2 cm. The dispersed oil of WLORW was relatively easily removed, and most of the oil removal was contributed by emulsified oil within 5-10 µm. Gas chromatography-mass spectrometry (GC-MS) analysis revealed that effective removal of the biorefractory organic compounds could contribute to the improvement of biodegradability of WLORW. Thus, the 5-day biochemical oxygen demand/chemical oxygen demand ratio (BOD5/COD) was significantly enhanced by 4.31 times, which highly benefits future biological treatment. The routes of WLORW removal could be concluded as charge neutralization, adsorption bridging, sweep flocculation, and air flotation. The results demonstrate that EC has potential as an effective pretreatment technology for WLORW biological treatment.

A review on the effect of light-thermal-humidity environment in sow houses on sow reproduction and welfare.

The environment in sow houses is the key to restrict sow production due to its significant effect on sow growth and reproduction. In this article, the effect of light, thermal and light-thermal-humidity environment in sow houses is systematically reviewed for sow reproduction and welfare according to the existing literature. The results show the optimal ambient temperature range for sows is approximately 16-22°C, as well as the lowest and highest critical temperature are 16 and 27°C respectively. Meanwhile, the increase of relative humidity from 50% to 70% is equivalent to the increase of effective temperature by 0.9°C in sow houses. In addition, the evaluation indexes are summarized to the future research direction is proposed according to the reviewed results. It can be concluded that the current research mainly focuses on the effect mechanism of light-thermal-humidity environment on sow growth and reproductive performance, as well as the optimal regulation range of light-thermal-humidity environment. In particular, it is a popular topic to further study the effect of light-thermal-humidity environment on the genetic material of sows, as well as metabolic parameters and body composition of their offspring. The above conclusions can contribute to guiding the regulation of light-thermal-humidity environment in sow houses and improving the sow welfare.

A systematic literature review on indoor PM2.5 concentrations and personal exposure in urban residential buildings.

Particulate matter with an aerodynamic diameter less than 2.5µm (PM2.5) is currently a major air pollutant that has been raising public attention. Studies have found that short/long-term exposure to PM2.5 lead detrimental health effects. Since people in most region of the world spend a large proportion of time in dwellings, personal exposure to PM2.5 in home microenvironment should be carefully investigated. The objective of this review is to investigate and summary studies in terms of personal exposure to indoor PM2.5 pollutants from the literature between 2000 and 2021. Factors from both outdoor and indoor environment that have impact on indoor PM2.5 levels were explicated. Exposure studies were verified relating to individual activity pattern and exposure models. It was found that abundant investigations in terms of personal exposure to indoor PM2.5 is affected by factors including concentration level, exposure duration and personal diversity. Personal exposure models, including microenvironment model, mathematical model, stochastic model and other simulation models of particle deposition in different regions of human airway are reviewed. Further studies joining indoor measurement and simulation of PM2.5 concentration and estimation of deposition in human respiratory tract are necessary for individual health protection.

Redox regulation of RAD51 Cys319 and homologous recombination by peroxiredoxin 1.

RAD51 is a critical recombinase that functions in concert with auxiliary mediator proteins to direct the homologous recombination (HR) DNA repair pathway. We show that Cys319 RAD51 possesses nucleophilic characteristics and is important for irradiation-induced RAD51 foci formation and resistance to inhibitors of poly (ADP-ribose) polymerase (PARP). We have previously identified that cysteine (Cys) oxidation of proteins can be important for activity and modulated via binding to peroxiredoxin 1 (PRDX1). PRDX1 reduces peroxides and coordinates the signaling actions of protein binding partners. Loss of PRDX1 inhibits irradiation-induced RAD51 foci formation and represses HR DNA repair. PRDX1-deficient human breast cancer cells and mouse embryonic fibroblasts display disrupted RAD51 foci formation and decreased HR, resulting in increased DNA damage and sensitization of cells to irradiation. Following irradiation cells deficient in PRDX1 had increased incorporation of the sulfenylation probe DAz-2 in RAD51 Cys319, a functionally-significant, thiol that PRDX1 is critical for maintaining in a reduced state. Molecular dynamics (MD) simulations of dT-DNA bound to a non-oxidized RAD51 protein showed tight binding throughout the simulation, while dT-DNA dissociated from an oxidized Cys319 RAD51 filament. These novel data establish RAD51 Cys319 as a functionally-significant site for the redox regulation of HR and cellular responses to IR.

Ultrastructural visualization of chromatin in cancer pathogenesis using a simple small-molecule fluorescent probe.

Imaging 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. It is, in part, hampered by the lack of simple labels that consistently generates high-quality STORM images on the highly processed clinical tissue. We developed a fast, simple, and robust small-molecule fluorescent probe-cyanine 5-conjugated Hoechst-for routine superresolution imaging of nanoscale nuclear architecture on clinical tissue. We demonstrated the biological and clinical significance of imaging superresolved chromatin structure in cancer development and its potential clinical utility for cancer risk stratification.

Robust emitter localization with enhanced harmonic analysis.

We present a non-iterative and model-free algorithm for three-dimensional (3D) single emitter localization. Our algorithm decodes the axial position and the emitter width via the ratio of the first and second Fourier harmonic. The retrieved width information is further used for dynamic extraction of the proper region of interest to robustly eliminate the outer noisy background, thus improving the localization precision over existing non-iterative algorithms. Using simulated and experimental datasets, we demonstrate that our algorithm achieves localization precision approaching the state-of-the-art iterative fitting-based methods in all three dimensions at two orders of magnitude faster speed, applicable in various 3D single-molecule localization techniques.

Enhanced super-resolution microscopy by extreme value based emitter recovery.

Super-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. Through numerical simulation and biological experiments, we validated the accuracy of EVER in improving the fidelity of the reconstructed super-resolution image for a wide variety of imaging characteristics. EVER requires no manual adjustment of parameters and has been implemented as an easy-to-use ImageJ plugin that can immediately enhance the quality of reconstructed super-resolution images. This method is validated as an efficient way for robust nanoscale imaging of samples with heterogeneous background fluorescence, such as thicker tissue and cells.

Embedded nanometer position tracking based on enhanced phasor analysis: erratum.

We present an erratum to our Letter [Opt. Lett.46, 3825 (2021)OPLEDP0146-959210.1364/OL.433740]. This erratum corrects an error in Eq. (2). All the simulations and experiments in the original Letter were performed using the correct equation, and therefore, this correction does not affect the results and conclusions of the original Letter.

Embedded nanometer position tracking based on enhanced phasor analysis.

We present an embedded real-time 1D position tracking device at a nanometer precision. The embedded algorithm extracts the most appropriate region of the signal without manual intervention and estimates the position based on the phase shift from the signal's first Fourier harmonic. Using simulated datasets, we demonstrate that the proposed approach can achieve a similar precision to the state-of-the-art maximum likelihood fitting-based method while executing over four orders of magnitude faster. We further implemented this algorithm on a low-power microprocessor and developed a simple, compact, and low-cost embedded position tracking device. We demonstrate nanometer tracking precision in real-time drift tracking experiments.

Optimized Stochastic Optical Reconstruction Microscopy for Imaging Chromatin Structure in Pathological Tissue.

Direct 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. We discuss detailed methods for fluorescence staining of DNA and histone proteins, as well as the key technical factors for obtaining high-quality STORM images in pathological tissue samples. © 2020 Wiley Periodicals LLC Basic Protocol 1: Fluorescence staining of chromatin in pathological tissue Basic Protocol 2: STORM data processing Support Protocol 1: Drift correction Support Protocol 2: Image reconstruction Support Protocol 3: Hematoxylin & eosin (H&E) staining.

RAB23 coordinates early osteogenesis by repressing FGF10-pERK1/2 and GLI1.

Mutations in the gene encoding Ras-associated binding protein 23 (RAB23) cause Carpenter Syndrome, which is characterized by multiple developmental abnormalities including polysyndactyly and defects in skull morphogenesis. To understand how RAB23 regulates skull development, we generated Rab23-deficient mice that survive to an age where skeletal development can be studied. Along with polysyndactyly, these mice exhibit premature fusion of multiple sutures resultant from aberrant osteoprogenitor proliferation and elevated osteogenesis in the suture. FGF10-driven FGFR1 signaling is elevated in Rab23-/-sutures with a consequent imbalance in MAPK, Hedgehog signaling and RUNX2 expression. Inhibition of elevated pERK1/2 signaling results in the normalization of osteoprogenitor proliferation with a concomitant reduction of osteogenic gene expression, and prevention of craniosynostosis. Our results suggest a novel role for RAB23 as an upstream negative regulator of both FGFR and canonical Hh-GLI1 signaling, and additionally in the non-canonical regulation of GLI1 through pERK1/2.

In many animals, the skull is made of several separate bones that are loosely joined during childhood and only fuse into one piece when the animal stops growing. A genetic disease called Carpenter syndrome causes the bones of the skull to fuse early in life, stopping it from growing correctly. Carpenter syndrome is often caused by changes to the gene responsible for making a protein called RAB23. RAB23 helps move other molecules and cell components between different parts of the cell, and is therefore involved in a number of cellular processes. Previous studies suggest that RAB23 has a role in many parts of the body during development. Yet, it is unclear which cells in the skull depend on RAB23 activity and how this protein is controlled. To answer this question, Hasan et al. grew pieces of developing skull bones that had been taken from mice lacking the RAB23 protein in the laboratory. Examining these samples revealed that RAB23 is active in cells called osteoblasts that add new bone to the edge of each piece of the skull as it grows. Hasan et al. also found that RAB23 regulates two cellular signaling pathways ­ called the hedgehog pathway and the fibroblast growth factor pathway ­ that interact with one another and co-ordinate skull development. These findings show how RAB23 controls the growth and fusion of skull bones in developing animals. This could improve our understanding of the role RAB23 plays in other processes during development. It also sheds light on the mechanisms of Carpenter syndrome which may inform new approaches for treating patients.

Study on the Pore and Microstructure Fractal Characteristics of Alkali-Activated Coal Gangue-Slag Mortars.

Just as it is regarding ordinary cement-based materials, the pore structure and microstructure of alkali-activated materials are disordered. It is essential to predict the macroscopic properties by studying the pore and microstructure fractal characteristics of materials. In this paper, the effects of slag content and alkali activator modulus on compressive strength, porosity, and microstructure of alkali-activated coal gangue-slag (AACGS) mortar were studied. Further, with the help of mercury intrusion porosimetry (MIP) data and the MATLAB programming, the pore and SEM photos fractal dimensions of AACGS mortar specimens were obtained, respectively, and the relationship between the microscopic fractal dimensions and the macroscopic strength and the structural characteristics of pores was established. The results show that the pore fractal dimension has a good linear relationship with the compressive strength and pore characteristic parameters (porosity, total pore area, and average pore diameter, etc.). With the increase of slag content, the SEM photos fractal dimension of AACGS mortar specimens increases, and the fractal dimension and compressive strength also show a significant positive linear relationship. The two fractal characterization methods can be used in the alkali-activated material system and have important guiding significance for predicting the macroscopic strength and pore characteristic parameters of the material.

Super-resolution imaging reveals the evolution of higher-order chromatin folding in early carcinogenesis.

Genomic 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. Our integrated imaging, genomic, and transcriptomic analyses reveal functional consequences in enhanced transcription activities and impaired genomic stability. We also demonstrate the potential of imaging higher-order chromatin disruption to detect high-risk precursors that cannot be distinguished by conventional pathology. Taken together, our findings reveal gradual decompaction and fragmentation of higher-order chromatin structure as an enabling characteristic in early carcinogenesis to facilitate malignant transformation, which may improve cancer diagnosis, risk stratification, and prevention.

Super-resolution localization microscopy: Toward high throughput, high quality, and low cost.

After nearly 15 years since its initial debut, super-resolution localization microscopy that surpasses the diffraction-limited resolution barrier of optical microscopy has rapidly gotten out of the ivory tower and entered a new phase to address various challenging biomedical questions. Recent advances in this technology greatly increased the imaging throughput, improved the imaging quality, simplified the sample preparation, and reduced the system cost, making this technology suitable for routine biomedical research. We will provide our perspective on the recent technical advances and their implications in serving the community of biomedical research.

Property Comparison of Alkali-Activated Carbon Steel Slag (CSS) and Stainless Steel Slag (SSS) and Role of Blast Furnace Slag (BFS) Chemical Composition.

In order to compare the properties of alkali-activated carbon steel slag (CSS) and stainless steel slag (SSS), the effects of sodium hydroxide/sodium silicate solution mass ratio (NH/NS), liquid/solid ratio and blast furnace slag (BFS) dosage on the compressive strength, hydration products and hydration degree of CSS and SSS were studied. Furthermore, a combination of X-ray diffraction (XRD), thermo-gravimetric analysis coupled with differential thermal analysis (TGA-DTA), Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscope-energy dispersive spectrometer (SEM-EDS) were used to characterize the morphology and structure of alkali-activated CSS-BFS and SSS-BFS cementitious materials. As the results revealed, the primary hydrate of alkali-activated CSS and SSS is C-(A)-S-H with Q2 [SiO4] units, which has a low Ca/Si ratio and includes inert phases like a CaO-FeO-MnO-MgO solid solution (RO) in CSS while cuspidine, magnesiochromite etc. in SSS. More active C3S and ß-C2S promote the alkali activation of CSS, whereas the less active γ-C2S hinders the depolymerization of SSS. The incorporation of BFS does not change the hydrate, whose seed effect is helpful for accelerating the depolymerization and polycondensation of CSS and SSS, especially for SSS, and makes the hydrate increase significantly. Owing to the high SiO2 and Al2O3 contents of SSS, the C-(A)-S-H chain length is increased, thus facilitating the polycondensation effect. In this study, the optimal NH/NS of CSS and SSS is NH/NS= 1:2, and the optimal liquid/solid ratio is 0.29. Compared to CSS-BFS, the C-(A)-S-H gel produced by SSS-BFS has lower Ca/Si and Al/Si ratios. Unlike CSS, pure SSS is inappropriate as an alkali-activated precursor and needs to be co-activated with BFS.

Preparation and Reaction Mechanism Characterization of Alkali-activated Coal Gangue-Slag Materials.

In this paper, slag is used as a calcium source to make alkali-activated coal gangue-slag (AACGS) based material. The reaction mechanism of AACGS materials was discussed in depth by means of XRD, FT-IR, 29Si MAS-NMR (nuclear magnetic resonance) and SEM-EDS (energy dispersive spectrometer). The experimental results show that coal gangue can be used as a raw material for preparing alkali-activated materials. The liquid-solid ratio is the most influential factor on AACGS paste fluidity and strength, followed by slag content. As the modulus of sodium hydroxide increases, the depolymerization process of the reactant precursor is accelerated, but the high sodium hydroxide concentration inhibits the occurrence of the early coal gangue-slag polycondensation reaction, and exerts little effect on the 28 d compressive strength. Ca2+ in the slag promotes exchange with Na+, and the product is converted from N-A-S-H gel to C-(A)-S-H gel, and C-(A)-S-H is formed with higher Ca/Si ratio with the increase of slag content. The slight replacement of coal gangue by slag can greatly improve the reaction process and the strength of AACGS materials.