Large Aggregates Research Articles

Interactions between DNA and a Pyrene-Labeled Surfactant Probed by Pyrene Excimer Formation, Transmission Electron Microscopy, and Dynamic Light Scattering.

The interactions between calf thymus DNA and a pyrene-labeled gemini surfactant termed PyO-3-12 were investigated by using dynamic light scattering (DLS), transmission electron microscopy (TEM), and pyrene excimer formation (PEF) between an excited and a ground-state pyrene. PyO-3-12 was prepared with two dimethylammonium bromide headgroups linked with a propyl spacer, with one ammonium bearing a dodecyl tail and the other bearing a 1-pyrenemethoxyhexyl pendent. The size and electrostatic properties of the colloidal species were characterized by DLS, and TEM was used to describe the overall dimensions and morphologies of the aggregates. PEF enabled the study of PyO-3-12 at the molecular level. The association of PyO-3-12 and DNA was studied in detail for two specific PyO-3-12 concentrations of 16 and 56 μM using a (∓) ratio equal to the [DNA]/[PyO-3-12] ratio with [DNA] expressed in terms of DNA base pairs, yielding a (∓) ratio ranging from 0.1 to 10. An increase in PyO-3-12 association upon adding DNA was detected through an increase in PEF. Analysis of the fluorescence decays indicated a progressive binding of PyO-3-12 to DNA until the equicharge point was reached after which all PyO-3-12 surfactants were bound to DNA. The formation of large colloidal aggregates was observed by DLS, which showed a spike in the hydrodynamic diameter (Dh) as the (∓) ratio approached unity. Analysis of the fluorescence spectra suggested that the excited pyrenyl labels experienced a more hydrophobic environment for the lipoplexes generated by the 56 μM PyO-3-12 solutions, which appeared smaller and more globular in the TEM images than the lipoplexes obtained with the lower 16 μM PyO-3-12 concentration. Together, these experiments suggest that the concentrations of the cationic gemini surfactants and DNA are important parameters for the morphology of lipoplexes with possible implications for their transfection efficiency.

Collective Deformation Modes Promote Fibrous Self-Assembly in Deformable Particles

The self-assembly of particles into organized structures is a key feature of living organisms and a major engineering challenge. While it may proceed through the binding of perfectly matched, puzzle-piece-like particles, many other instances involve ill-fitting particles that must deform to fit together. These include some pathological proteins, which have a known propensity to form fibrous aggregates. Despite this observation, the general relationship between the individual characteristics of the particles and the overall structure of the aggregate is not understood. To elucidate it, we analytically and numerically study the self-assembly of two-dimensional, deformable ill-fitting particles. We find that moderately sticky particles tend to form equilibrium self-limited aggregates whose size is set by an elastic boundary layer associated with collective deformations that may extend over many particles. Particles with a soft internal deformation mode thus give rise to large aggregates. In addition, when the particles are incompressible, their aggregates tend to be anisotropic and fiberlike. Our results are preserved in a more complex particle model with randomly chosen elastic properties. This indicates that generic proteinlike characteristics such as allostery and incompressibility could favor the formation of fibers in protein aggregation, and suggests design principles for artificial self-assembling structures. Published by the American Physical Society 2025

Soil Aggregate Stability and Characteristics of Nitrogen, Phosphorus, and Potassium Contents in Cut Slope Soils With Different Aspects in Plateau Areas

ABSTRACTSlope aspects can affect the soil‐forming process. The implementation of road construction projects in plateau regions has resulted in the formation of numerous cut slopes. However, the soil aggregate stability and the characteristics of soil nitrogen (N), phosphorus (P), and potassium (K) nutrients under different cut slope aspects (east‐facing slope (EFS), west‐facing slope (WFS), south‐facing slope (SFS) and north‐facing slope (NFS)) are still unclear. In this context, the present study aims to assess the characteristics and influencing factors of soil aggregate stability, as well as N, P, and K contents, under different slope aspects in typical cut slope soils with the four different aspects in the southwestern plateau of China. In addition, the relationships of the soil aggregate stability with the soil N, P, and K contents were further explored in this study. The results showed significant differences in the soil aggregate stability (MWD, mean weight diameter) between the four slope aspects. The MWD values of the WFS and SFS were 1.18 and 1.16, respectively, which were significantly higher than those of the EFS and NFS (p < 0.05). Large macroscopic aggregates (LMA) showed the greatest contribution to the MWD values. The soil total phosphorus (TP), total nitrogen (TN), total potassium (TK), alkali‐hydrolyzed nitrogen (AN), available phosphorus (AP), available potassium (AK), and soil organic carbon (SOC) contents showed significant differences between the four slope aspects and soil particle sizes. However, comparatively lower SOC contents were observed in the silt and clay fraction (SCA). The SOC contents and soil pH were the major factors influencing the LMA and SCA, which, in turn, affected the soil aggregate stability and contents of N, P, and K. The current study provides a useful reference for improving the quality of cut slope soils.

Biofilm characterisation of Mycoplasma bovis co-cultured with Trueperella pyogenes

Mycoplasma pneumonia, caused by Mycoplasma bovis (Mycoplasmopsis bovis; M. bovis), is linked with severe inflammatory reactions in the lungs and can be challenging to treat with antibiotics. Biofilms play a significant role in bacterial persistence and contribute to the development of chronic lesions. A recent study has shown that polymicrobial interactions between species are an important factor in biofilm formation, yet the precise mechanism of biofilm formation in M. bovis remains unknown. By assuming multiple pathogen infections in the bovine respiratory disease complex (BRDC), this study examined the characterisation of the polymicrobial relationship between M. bovis and Trueperella pyogenes (T. pyogenes) during biofilm formation. Autopsies were performed on four Holstein calves (two chronic Mycoplasma pneumonia calves and two control calves). Bacterium-like aggregation structures (> 10 μm), which were assumed to be biofilms of M. bovis in vivo, were observed adhering to the cilia in calves with Mycoplasma pneumonia. M. bovis released an extracellular matrix to connect with neighbouring bacteria and form a mature biofilm on the plate. Biofilm formation in the co-culture of M. bovis and T. pyogenes (strain T1: 1 × 105 and 1 × 106 CFU/well) significantly increased (p < 0.05 and p < 0.01; 64.1% and 64.8% increase) compared to that in a single culture of these bacteria. Furthermore, some large aggregates (> 40 μm), composed of M. bovis and T. pyogenes, were observed. The morphological characteristics of this biofilm were similar to those observed in vivo compared to a single culture. In conclusion, the polymicrobial interaction between M. bovis and T. pyogenes induces biofilm formation, which is associated with increased resistance to antimicrobial agents, and this exacerbates the progression of chronic Mycoplasma pneumonia.

REVISITING THE PHYSICAL AND CHEMICAL NATURE OF THE MINERAL COMPONENT OF BONE.

The physico-chemical characteristics of bone mineral remain heavily debated. On the nanoscale, bone mineral resides both inside and outside the collagen fibril as distinct compartments fused together into a cohesive continuum. On the micrometre level, larger aggregates are arranged in a staggered pattern described as crossfibrillar tessellation. Unlike geological and synthetic hydroxy(l)apatite, bone mineral is a unique form of apatite deficient in calcium and hydroxyl ions with distinctive carbonate and acid phosphate substitutions (CHAp), together with a minor contribution of amorphous calcium phosphate as a surface layer around a crystalline core of CHAp. In mammalian bone, an amorphous solid phase has not been observed, though an age-dependent shift in the amorphous-to-crystalline character is observed. Although octacalcium phosphate has been postulated as a bone mineral precursor, there is inconsistent evidence of calcium phosphate phases other than CHAp in the extracellular matrix. In association with micropetrosis, magnesium whitlockite is occasionally detected, indicating pathological calcification rather than a true extracellular matrix component. Therefore, the terms 'biomimetic' or 'bone-like' should be used cautiously in descriptions of synthetic biomaterials. The practice of reporting the calcium-to-phosphorus ratio (Ca/P) as proxy for bone mineral maturity oversimplifies the chemistry since both Ca2+ and PO43- ions are partially substituted. Moreover, non-mineral sources of phosphorus are ignored. Alternative compositional metrics should be considered. In the context of bone tissue and bone mineral, the term 'mature' must be used carefully, with clear criteria that consider both compositional and structural parameters and the potential impact on mechanical properties. STATEMENT OF SIGNIFICANCE: Bone mineral exhibits a unique hierarchical structure and is classified as intrafibrillar and extrafibrillar mineral compartments with distinct physico-chemical characteristics. The dynamic nature of bone mineral, i.e., evolving chemical composition and physical form, is poorly understood. For instance, bone mineral is frequently described as "hydroxy(l)apatite", even though the OH- content of mature bone mineral is negligible. Moreover, the calcium-to-phosphorus ratio is often taken as an indicator of bone mineral maturity without acknowledging substitutions at calcium and phosphate sites. This review takes a comprehensive look at the structure and composition of bone mineral, highlighting how experimental data are misinterpreted and unresolved concerns that warrant further investigation, which have implications for characterisation of bone material properties and development of bone repair biomaterials.

Silica Nanoparticle-Protein Aggregation and Protein Corona Formation Investigated with Scattering Techniques.

Protein-nanoparticle interactions and the resulting corona formation play crucial roles in the behavior and functionality of nanoparticles in biological environments. In this study, we present a comprehensive analysis of protein corona formation with superfolder green fluorescent protein (sfGFP) and bovine serum albumin in silica nanoparticle dispersions using small-angle X-ray scattering (SAXS) and dynamic light scattering (DLS). For the first time, we subtracted the scattering of individual proteins in solution and individual nanoparticles from the protein-nanoparticle complexes. This approach effectively isolated the contributions of specific components within the corona. Our form factor analysis revealed consistent core-shell sphere thicknesses but varied attractive interaction strengths of the nanoparticle complexes, influenced by the protein corona and the surface properties of silica and aminated silica nanoparticles. Interestingly, fractal analysis of nanoparticles showed a transition from surface to mass fractals for sfGFP samples at high protein:nanoparticle molar ratios of over 264,000:1. DLS analysis highlighted aggregation behaviors, including the increasing size of protein-nanoparticle complexes and significant aggregation of both free proteins and complexes at ∼264,000 molar ratio. Large polydispersity and heterogeneous protein aggregation were observed at these high molar ratios. Both SAXS and DLS revealed transitions and changes in protein-nanoparticle interactions at molar ratios of 4000 to 44,000, consistent with corona formation, while pronounced aggregation was observed at a molar ratio of ∼264,000. These findings advance our understanding of the structural complexities in protein-nanoparticle association and suggest further avenues for refining characterization techniques in protein corona research.

Soil Aggregation, Aggregate Stability, and Associated Soil Organic Carbon in Huron Mountains Forests, Michigan, USA

Soil organic carbon (SOC) plays a critical role in regulating the global carbon (C) cycle, with forest soils serving as significant C sinks. Soil aggregate stability and the distribution of SOC in different aggregate fractions would be affected by different forest types. In this study, we investigate the distribution and dynamics of SOC within different soil aggregate fractions across three main forest types in the Huron Mountains, Michigan, USA: white birch–eastern hemlock mixed forest, eastern-hemlock-dominated forest, and sugar maple forest. We hypothesize that variations in species composition and soil depth influence SOC storage and aggregate stability through mechanisms such as root interactions, microbial activity, and soil structure development. Soil samples were collected from three depth intervals (0–20 cm, 20–40 cm, and 40–60 cm) and analyzed for aggregate size distribution and SOC content. The results showed that aggregate size distribution and SOC stocks differ significantly across forest types, with the white birch–eastern hemlock mixed forest exhibiting the highest proportion of large aggregates (&gt;1.0 mm), which contribute to more stable soil structures. This forest type also had the highest total aggregate mass and mean weight diameter, indicating enhanced soil stability. In contrast, sugar maple forest displayed a greater proportion of smaller aggregates and a lower macroaggregate-to-microaggregate ratio, suggesting fewer stable soils. SOC stocks were closely linked to aggregate size, with macroaggregates containing the highest proportion of SOC. These differences in SOC distribution and soil aggregate stability can be attributed to several underlying mechanisms, including variations in plant root interactions, microbial activity, and the physical properties of the soil. Forests with diverse species compositions, such as the white birch–eastern hemlock mixed forest, tend to support more complex root systems and microbial communities, leading to improved soil aggregation and greater SOC storage. Additionally, forest management practices such as selective thinning and mixed-species planting contribute to these processes by enhancing soil structure, increasing root biomass, and promoting soil microbial health. These interactions play a crucial role in enhancing C sequestration and improving soil health. Our findings emphasized the importance of forest composition in influencing SOC dynamics and soil stability, offering insights into the role of forest management in C sequestration and soil health. This study provided a reference to a deeper understanding of SOC storage potential in forest ecosystems and supports the development of sustainable forest management strategies to mitigate climate change.

Insights into the morphology-productivity relationship of filamentous fungi through small-scale cultivation and automated microscopy of Thermothelomyces thermophilus.

Filamentous fungi are a cornerstone in the biotechnological production of enzymes, proteins, and organic acids. However, challenges in understanding and controlling the relationship between morphology and productivity can limit their application. This study addresses these challenges using Thermothelomyces thermophilus, a promising thermophilic fungus known for the production of thermostable enzymes. We investigated the effects of environmental conditions on fungal morphology and enzyme production using a combination of microbioreactor cultivation, automated liquid handling, and automated microscopy. Specifically, batch and fed batch cultivations were performed at different pH levels and glucose feeding rates to study their effects on secretory phytase production, fungal growth, and morphology. Results from batch cultivations revealed a two-fold higher phytase activity at pH 5.5 compared to pH 6.5, with notably smaller fungal fragments at the end of cultivation. Conversely, fed batch cultivations at a feeding rate of 1 g (l h)-1 glucose showed a 1.6-fold higher enzyme activity at pH 5.5, accompanied by much larger fungal aggregates throughout the feeding phase. These findings suggest that large aggregates are associated with high productivity; however, their breakdown further enhances enzyme release, increasing activity in the supernatant. This study not only provides insights on the morphology-productivity relationship of T. thermophilus, but also demonstrates the efficacy of integrating microbioreactors with automated microscopy. This methodology represents a significant advance in the field of fungal biotechnology, paving the way for more efficient industrial bioprocesses.

Toxicological problems of tattoo removal: characterization of femtosecond laser-induced fragments of Pigment Green 7 and Green Concentrate tattoo ink.

Femtosecond lasers represent a novel tool for tattoo removal as sources that can be operated at high power, potentially leading to different removal pathways and products. Consequently, the potential toxicity of its application also needs to be evaluated. In this framework, we present a comparative study of Ti:Sapphire femtosecond laser irradiation, as a function of laser power and exposure time, on water dispersions of Pigment Green 7 (PG7) and the green tattoo ink Green Concentrate (GC), which contains PG7 as its coloring agent. The treated samples were subsequently analyzed via UV‒Vis spectroscopy, gas chromatography‒mass spectrometry (GC‒MS), SEM imaging and associated statistical analysis. We found that, on average, the discoloration efficacy of femtosecond laser treatment was comparable to that of nanosecond lasers as were the decomposition products. In fact, two primary types of fragments are produced, both of which are potentially harmful, resulting either from the decomposition of chlorinated phthalocyanine (i.e., PG7) or from the active chlorination of naphthalene impurities. However, the outcomes for the PG7 and GC treatments differed significantly from each other from several points of view. The spectral intensity patterns of GC and PG7 were distinct, depending on the treatment conditions, and showed linearity with power only in the case of GC. Additionally, the relative ratios of the fragment products differed significantly, with the production rate showing a linear dependence on power only in the case of GC and no discernible trend for PG7. Shape and size distribution of the generated particles were highly dependent on the type of sample. Femtosecond laser irradiation of GCs primarily produces nanoparticles with a homogeneous size distribution, which are typically considered nontoxic. Large aggregates also formed, exhibiting a regular shape. In contrast, PG7 yielded rods and needles with aspect ratios similar to those of toxic fibers.

The Impact of Targeted Therapies on Red Blood Cell Aggregation in Patients with Chronic Lymphocytic Leukemia Evaluated Using Software Image Flow Analysis.

Chronic lymphocytic leukemia (CLL), the most common type of leukemia, remains incurable with conventional therapy. Despite advances in therapies targeting Bruton's tyrosine kinase and anti-apoptotic protein BCL-2, little is known about their effect on red blood cell (RBC) aggregation in blood flow. In this study, we applied a microfluidic device and a newly developed Software Image Flow Analysis to assess the extent of RBC aggregation in CLL patients and to elucidate the hemorheological effects of the commonly applied therapeutics Obinutuzumab/Venetoclax and Ibrutinib. The results revealed that, in RBC samples from untreated CLL patients, complex 3D clusters of large RBC aggregates are formed, and their number is significantly increased compared to healthy control samples. The application of the Obinutuzumab/Venetoclax combination did not affect this aspect of RBCs' rheological behavior. In contrast, targeted therapy with Ibrutinib preserves the aggregation state of CLL RBCs to levels seen in healthy controls, demonstrating that Ibrutinib mitigates the alterations in the rheological properties of RBCs associated with CLL. Our findings highlight the alterations in RBC aggregation in CLL and the impact of different targeted therapies on RBCs' rheological properties, which is critical for predicting the potential complications and side effects of CLL treatments, particularly concerning blood flow dynamics.

Trapping Anions within Stacks of Tetra-Urea Macrocycles.

Designing molecular receptors that bind anions in water is a significant challenge, and an even greater difficulty lies in using these receptors to remove anions from water without resorting to the hazardous liquid-liquid extraction approach. We here demonstrate an effective and synthetically simple strategy toward these goals by exploiting ion-pair assembly of macrocycles. Our anion binding ensemble consists of an octa-chloro tetra-urea macrocyclic anion receptor (ClTU), which forms water-dispersible aggregates, and a tetra-cationic fluorescent dye 5,10,15,20-tetrakis(1-methyl-4-pyridinio)porphyrin (TMPyP4), which provides Coulombic stabilization and fluorescence reporting of anion binding in an ion-pair assembly. The ability of ClTU to form oligomeric/polymeric stacks with chloride ions and countercations was demonstrated by X-ray crystallographic and 1H NMR studies in DMSO. In water, the addition of anions to a mixture of ClTU and TMPyP4 led to the formation of ion-pair assemblies showing quenched fluorescence from TMPyP4 and apparent selectivity in the order of CrO42- ≈ SO42- > Cl- > ClO4- ≈ NO3- > AcO- > F- > H2PO4-. The assembly can be applied to remove traces of toxic CrO42- anions from tap water simply by using syringe filters to separate large aggregates from water. Molecular dynamics studies support the formation of columnar stacks of ClTU in solution, which allow for insertion of both anionic guests and cationic TMPyP4 dyes.

Seasonal variation in roost climate and emergence behaviour in a colony of the highly gregarious wrinkle-lipped free-tailed bat (Mops plicatus)

ABSTRACT As obligate nocturnal mammals, most bats spend the day hiding in dark shelters, sometimes as gregarious colonies. Roosting in such large colonies may have the advantage of reducing thermoregulatory costs, as the heat dissipated by thousands of bodies raises the temperature of the cave interior. However, bats in large aggregations may also suffer from increased predation risk. Here we studied the effect of a highly gregarious Palaeotropical bat, the wrinkle-lipped free-tailed bat (Mops plicatus), on cave temperature and the factors that influence its emergence behaviour. We studied cave temperature, prey abundance, emergence behaviour and attack rates by birds of prey during colony emergence. The study was made at Khao Wongkot Cave, counting more than one million individuals. In all seasons, we observed that the presence of M. plicatus caused relatively higher temperatures of around 30°C inside the cave, while temperatures outside were lower and more variable. This suggests that the body heat of aggregated bats raised the temperature inside the cave, presumably close to the thermo-neutral zone at the roosting sites of bats. Arthropod abundance was highest during late pregnancy/early lactation and lowest during late lactation/post lactation. Bats emerged earliest during the late wet season and latest during the hot season. During periods of high predation risk, bats always emerged as a column, whereas during periods of low predation risk (hot and early wet seasons), individual bats left first, before a column of bats formed, 10 to 20 min after the first individuals exited the cave. Our study highlights that large colonies may provide thermoregulatory benefits that could increase individual fitness. However, aggregations also increase predation costs during emergence. Bats form a column when aerial predator attacks are most frequent. Also, bats seem to adjust their emergence timing in response to seasonal changes in predation risk.

Impact of GAUT1 Gene Knockout on Cell Aggregation in Arabidopsis thaliana Suspension Culture.

The development of efficient producers of recombinant pharmaceuticals based on plant cell suspension cultures is a pressing challenge in modern applied science. A primary limitation of plant cell cultures is their relatively low yield of the target protein. One strategy to enhance culture productivity involves reducing cell aggregation. In order to minimize cell-to-cell adhesion in culture, we used Cas9 endonuclease to knock out the GAUT1 gene, which is a key gene of pectin biosynthesis in the genome of Arabidopsis thaliana. The resulting knockouts exhibited altered phenotypes and were unable to form viable plants. The suspension cell culture induced from seedlings bearing a homozygous deletion in the GAUT1 gene displayed darker coloration and an increased number of large aggregates compared to the control. The biomass accumulation rate showed no difference from the control, while the level of recombinant GFP protein accumulation was significantly reduced. Thus, our findings indicate that disruptions in pectin synthesis and the formation of larger aggregates in the suspension cell culture adversely affect the accumulation of the target recombinant protein. Alternative targets should be sought to reduce cell aggregation levels in plant cell cultures through genome editing.

Bacterial contamination in public transport during COVID-19 pandemic: Characterization of an unusual Staphylococcus aureus isolate tolerant to vancomycin.

Public transport represents a potential site for the transmission of resistant pathogens due to the rapid movement of large numbers of people. This study aimed to investigate the bacterial contamination of frequently touched surfaces in the public transport system operating in the proximity of the biggest Czech hospital during the coronavirus pandemic despite extensive cleaning and disinfection efforts. In June and September 2020, samples from the metro trains, ground transport and stationary objects were collected, enriched and cultured. The antimicrobial susceptibility was tested by broth microdilution. Staphylococcus aureus isolates exhibiting inconclusive results of vancomycin susceptibility testing were retested by broth macrodilution and subjected to whole genome sequencing. All S. aureus isolates were tested for vancomycin heteroresistance (hVISA). A total of 513/542 (94.6 %) samples were culture-positive with higher frequency in September (p = 0.004). S. aureus was the most frequent opportunistic bacterial pathogen found (3.7 %, 20/542) followed by Enterobacterales spp. (1.8 %, 10/542). No methicillin-resistant S. aureus (MRSA), extended-spectrum beta-lactamase producers (ESBL) or carbapenemase-producing bacteria were detected. Resistance to clinically relevant drugs was rare except for resistance to ampicillin (67 %, 8/12), cefuroxime (42 %, 5/12) in Enterobacterales and chloramphenicol (90 %, 18/20), penicillin (45 %, 9/20), and erythromycin (20 %, 4/20) in S. aureus. One S. aureus isolate was shown to be resistant to vancomycin (8 mg/L) by forming large visible cell aggregates. Population analysis profile-area under the curve ratio (PAP-AUC) testing did not confirm the hVISA phenotype, but mutations in the hVISA phenotype-related gene vraR and other genes related to cell wall synthesis (fmtB) and intercellular adhesion (sasC) were found. Our study shows that in the COVID-19 pandemic, despite the intensive use of disinfectants, public transport was a source of opportunistic bacterial pathogens including S. aureus with unusual vancomycin resistance phenotype that could be easily missed by standard susceptibility testing.

Modeling aerobic granules in continuously flowing wastewater-treatment processes.

Continuously flowing wastewater-treatment processes can be configured for biological and physical selection to form and retain large biological aggregates (LBAs), along with suspended biomass that contains ordinary biological flocs and biomass that has detached from the LBAs. Suspended biomass and LBAs have different solids residence times (SRTs) and mass-transport resistances. Here, mathematical sub-models that describe metabolic processes, a 1-D biofilm, and spherical carriers that can migrate throughout a wastewater-treatment process were combined to simulate a full-scale demonstration train having anaerobic, anoxic, and oxic zones, as well as side-stream enhanced biological phosphorus removal. Hydrocyclones were utilized for physical selection. Simulation results and experimental observations agreed for soluble chemical oxygen demand, nitrogen, and phosphorus removals, as well as mixed liquor concentration and characteristics. The model outputs demonstrated that suspended biomass was responsible for most of the transformations in the bioreactor, but LBAs contributed importantly to P accumulation as polyphosphate. The simulated LBAs accumulated a higher density of phosphorus-storing bacteria, polyphosphate, and total- and protein-extracellular polymeric substances (EPS), particularly near their core. Protein-EPS accumulated near the substratum because protein-EPS hydrolyzed more slowly than carbohydrate-EPS, while the SRT in each layer increased from the surface layer to the layer adjacent to the LBA core. PRACTITIONER POINTS: Combined models well represented observed solids components in a full-scale demonstration train as A2O with S2EBPR. Simulations described aerobic-granule structure and function consistent with what is known about aerobic granules in BNR processes. Suspended biomass dominated most of the simulated transformation rates, but the LBAs accumulated ~2000 mg P/L as polyphosphosphate. The simulated aerobic granules did not intensify WWT overall but should have improved the net solids-settling characteristics. Aerobic granules had more EPS than the suspended biomass and protein-EPS accumulated inside the LBA by slower hydrolysis kinetics.

Dual-Amplification Single-Particle ICP-MS Strategy Based on Strand Displacement Amplification-CRISPR/Cas12a Amplification for Homogeneous Detection of miRNA.

MicroRNAs (miRNAs) regulate a myriad of biological processes and thus have been regarded as useful biomarkers in biomedical research and clinical diagnosis. The specific and highly sensitive detection of miRNAs is of significant importance. Herein, a sensitive and rapid dual-amplification elemental labeling single-particle inductively coupled plasma-mass spectrometry (spICP-MS) analytical method based on strand displacement amplification (SDA) and CRISPR/Cas12a was developed for miRNA-21 detection. Taking gold nanoparticles (AuNPs) as the elemental labels, the Au NP probe initially hybridized with linker DNA, forming large aggregates. In the absence of target miRNA-21, large aggregates of AuNPs will produce high pulse signals in spICP-MS detection. In the presence of the target miRNA-21, it triggered the SDA reaction, and the SDA products activated CRISPR/Cas12a's trans-cleavage activity to cleave the linker DNA, resulting in disassembly of the AuNP aggregates. The AuNP aggregates with smaller size displayed lower pulse signals in spICP-MS detection. Under the optimal conditions, a good relationship between the average pulse signal intensity of AuNP aggregates and the concentration of miRNA-21 was obtained in the range of 0.5 fmol L-1-100 pmol L-1 with a quantification limit as low as 0.5 fmol L-1. The developed method was successfully used for determination of miRNA-21 in human breast cancer cell lines (SK-BR-3 and MCF-7) and real blood samples from breast cancer patients. It is versatile, can be adapted to detect other targets by modifying the specific sequence of the SDA template chain that is complementary to the analytes, and offers a promising strategy for detecting various biomarkers with high sensitivity and specificity.

How Will Concrete Piles for Offshore Wind Power Be Damaged Under Seawater Erosion? Insights from a Chemical-Damage Coupling Meshless Method.

Based on the background of the continuously rising global demand for clean energy, offshore wind power, as an important form of renewable energy utilization, is booming. However, the pile foundations of offshore wind turbines are subject to long-term erosion in the harsh marine environment, and the problem of corrosion damage is prominent, which seriously threatens the safe and stable operation of the wind power system. In view of this, a meshless numerical simulation method based on smoothed particle hydrodynamics (SPH) and a method for generating the concrete meso-structures are developed. Concrete pile foundation models with different aggregate contents, particle sizes, and ion concentration diffusion coefficients are established to simulate the corrosion damage processes under various conditions. The rationality of the numerical algorithm is verified by a typical example. The results show that the increase in the aggregate percentage gradually reduces the diffusion rate of chemical ions, and the early damage development also slows down. However, as time goes, the damage will still accumulate continuously; when the aggregate particle size increases, the ion diffusion becomes more difficult, the damage initiation is delayed, and the early damage is concentrated around the large aggregates. The increase in the ion diffusion coefficient significantly accelerates the ion diffusion process, promotes the earlier and faster development of damage, and significantly deepens the damage degree. The research results contribute to a deeper understanding of the corrosion damage mechanisms of pile foundations and providing important theoretical support for optimizing the durability design of pile foundations. It is of great significance for ensuring the safe operation of offshore wind power facilities, prolonging the service life, reducing maintenance costs, and promoting the sustainable development of offshore wind power.

Asymmetrically PEGylated and amphipathic heptamethine indocyanine dyes potentiate radiotherapy of renal cell carcinoma via mitochondrial targeting

Enhancing the sensitivity of radiotherapy (RT) towards renal cell carcinoma (RCC) remains a challenge because RCC is a radioresistant tumor. In this work, we design and report asymmetrically Polyethylene Glycol (PEG)ylated and amphipathic heptamethine indocyanine dyes for efficient radiosensitization of RCC treatment. They were synthesized by modifying different lengths of PEG chains as hydrophilic moieties on one N-alkyl chain of a mitochondria-targeting heptamethine indocyanine dye (IR-808), and a radiosensitizer 2-nitroimidazole (NM) as a hydrophobic moiety on another N-alkyl chain. The PEG modification significantly improved water solubility, decreased the intermolecular π–π large aggregates, thereby enhanced renal excretion. The asymmetrical and amphipathic modification enhanced the preferential accumulation in renal tumors through self-assembly into small-size nanoparticles in aqueous environment. Radiosensitization was further improved by preferential accumulation in renal tumor cells and their mitochondria as mitochondria play a crucial role in rapid cancer cell growth, metastasis, and RT resistance. Additionally, the modification also increased the abilities of fluorescence emission and photostability, which is meaningful for imaging-guided precise RCC RT. Therefore, our findings may present a theranostic radiosensitizer for renal tumor-targeted imaging and radiosensitization.Graphical

The Influence of Resin Volume Fraction on Selected Properties of Polymer Concrete.

Polymer concrete is a promising material with applications in construction and architecture; however, guidelines for its design and optimization are not well-established in the literature. This study aimed to evaluate how resin volume fraction and aggregate size distribution affect key properties of polyester polymer concrete, including flexural strength, compressive strength, water absorption, and material cost. Three types of quartz aggregates with different particle size distributions were used, as follows: small (below 0.5 mm, quartz dust), medium (0.2-2.0 mm, quartz sand), and large (2.0-10.0 mm, quartz gravel). The resin volume content varied from 5% to 30%. Differences in apparent density, open porosity, water absorption, flexural strength, compressive strength, and material cost were analyzed as functions of resin volume content and aggregate size. The results showed that apparent density and mechanical properties are positively correlated with resin content for small and medium aggregates; however, in the case of large aggregates, flexural strength decreased when the resin volume content exceeded 20%. A significant reduction in material porosity and water absorption (to ~0.4% and ~0.2%, respectively) was observed at high resin volume fractions.

Research on Detection of Icing Cover Transmission Lines Under Different Weather Conditions Based on Wide-Field Dynamic Convolutional Network LDKA-NET

The safety of transmission lines is a crucial guarantee for the operation of the power grid. To address the issue of low detection accuracy for icing transmission line defects with existing models, this paper proposes a defect detection algorithm for icing transmission line defects under different weather conditions based on a Large Dynamic Kernel Aggregation Net (LDKA-NET). First, a wide field of view convolutional network (WFVC Net) is introduced to enhance the network’s perception and generalization capabilities, enabling better adaptation to complex scene targets. Secondly, a full-dimensional dynamic convolutional feature fusion network is proposed, which strengthens the model’s feature extraction ability by learning linear combinations of multiple convolution kernels and their weighted input-related attention. Finally, an Expectation Maximization Dynamic Convolutional Attention (EM-DCA) mechanism is introduced, which focuses on and utilizes important information in the input data to help the model better allocate attention, thereby improving its generalization and robustness. Experimental results show that on the dataset proposed in this paper, the average accuracy of the improved algorithm (mAP@0.5) reaches 99.01%. The model parameters decreased by 47.7 M compared with the baseline model and 91.26 M compared with the Faster region with CNN feature (Faster R-CNN) model. The accuracy is 4.81% and 3.11% higher than the SSD model and YOLOv5-L model, respectively. Compared with the existing models, our model is smaller and has higher detection accuracy. It can accurately detect ice-covered wires and complete the task of the ice-covered detection of transmission lines.