Large Aggregates Research Articles

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

Integrating 3D Bioprinting and Organoids to Better Recapitulate the Complexity of Cellular Microenvironments for Tissue Engineering.

Organoids, with their capacity to mimic the structures and functions of human organs, have gained significant attention for simulating human pathophysiology and have been extensively investigated in the recent past. Additionally, 3D bioprinting, as an emerging bio-additive manufacturing technology, offers the potential for constructing heterogeneous cellular microenvironments, thereby promoting advancements in organoid research. In this review, the latest developments in 3D bioprinting technologies aimed at enhancing organoid engineering are introduced. The commonly used bioprinting methods and materials for organoids, with a particular emphasis on the potential advantages of combining 3D bioprinting with organoids are summarized. These advantages include achieving high cell concentrations to form large cellular aggregates, precise deposition of building blocks to create organoids with complex structures and functions, and automation and high throughput to ensure reproducibility and standardization in organoid culture. Furthermore, this review provides an overview of relevant studies from recent years and discusses the current limitations and prospects for future development.

The disordered effector RipAO of Ralstonia solanacearum destabilizes microtubule networks in Nicotiana benthamiana cells.

Ralstonia solanacearum causes bacterial wilt, a devastating disease in solanaceous crops. The pathogenicity of R. solanacearum depends on its type III secretion system, which delivers a suite of type III effectors into plant cells. The disordered core effector RipAO is conserved across R. solanacearum species and affects plant immune responses when transiently expressed in Nicotiana benthamiana. Specifically, RipAO impairs pathogen-associated molecular pattern-triggered reactive oxygen species production, an essential plant defense mechanism. RipAO fused to yellow fluorescent protein initially localizes to filamentous structures, resembling the cytoskeleton, before forming large punctate aggregates around the nucleus. Consistent with these findings, tubulin alpha 6 (TUA6) and tubulin beta-1 (TUB1), building blocks of microtubules, were identified as a putative targets of RipAO in immunoprecipitation and mass spectrometry analyses. In the presence of RipAO, TUA6-labeled microtubules fragmented into puncta, mimicking the effects of oryzalin, a microtubule polymerization inhibitor. These effects were corroborated in a N. benthamiana transgenic line constitutively expressing GFP-labeled TUA6, where RipAO reduced microtubule density and stability at an accumulation level that did not induce aggregation. Moreover, oryzalin treatment further enhanced RipAO's impairment of ROS production, suggesting that RipAO disrupts microtubule networks via its association with tubulins, leading to immune suppression. Further research into RipAO's interaction with the microtubule network will enhance our understanding of bacterial strategies to subvert plant immunity.

Dysregulation of protein degradation and alteration of secretome in α-synuclein-exposed astrocytes: implications for dopaminergic neuronal dysfunction

BackgroundA key factor in the propagation of α-synuclein pathology is the compromised protein quality control system. Variations in membrane association and astrocytic uptake between different α-synuclein forms suggest differences in exocytosis or membrane cleavage, potentially impacting the secretome's influence on dopaminergic neurons. We aimed to understand differences in protein degradation mechanisms of astrocytes for both wild-type (WT) and mutant forms of α-synuclein, specifically during periods of reduced degradation efficiency. We also investigated α-synuclein release into the secretome and its effects on healthy dopaminergic neurons.MethodsCellular models used were rat primary astrocytes alongside hiPSC-derived astrocytes, whose impact on rat primary dopaminergic neurons and the human SH-SY5Y cell line was investigated. We examined the release and accumulation of α-synuclein resulting from impaired degradatory pathways, including matrix metalloprotease-MMP9, the ubiquitin proteasomal pathway-UPS, and the autophagy-lysosomal pathway-ALP, using immunocytochemical analysis and flow cytometry. Additionally, we explored the effect of astrocytic secretome on dopaminergic-neuronal survival, neurite collapse and function.ResultsAt early stages, astrocytes were able to deal efficiently with monomeric α-synuclein (via UPS), and larger aggregates (through MMP9 and autophagy), clearing extracellular α-synuclein and maintaining neuronal health. However, extended exposure to extracellular monomeric and aggregated α-synuclein compromised their proteasomal activity, inhibiting MMP9 and destabilizing autophagy, transforming astrocytes from protectors to promoters of neurodegeneration. This study is the first to elucidate the astrocytes' preferred degradation pathways for both monomeric and aggregated forms of α-synuclein, along with the subsequent effects of these payloads on the cellular degradation machinery. The astrocytic transformation is characterized by α-synuclein expulsion, increased release of inflammatory cytokines, and diminished secretion of growth factors leading to dopaminergic neuronal apoptosis and dysfunction, particularly neurite collapse, intracellular Ca2+ response and vesicular dopamine release. The presence of phosphorylated and nitrated α-synuclein species in astrocytes also suggests their potential involvement in modifying both forms of the protein.ConclusionThe initial protective action of astrocytes in clearing and degrading extracellular α-synuclein is severely compromised at latter stages, leading to astrocytic dysfunction and impairing neuron-glia cross-talk. This study underscores the criticality of integrating astrocytes into treatment paradigms in synucleinopathies.

A new occurrence of hydrous andradite within pyroclastic rocks of the Sierra De Bahoruco, Dominican Republic

The titanium-bearing (up to 3.31 wt% TiO2) hydrous andradite [Ca2.98Na(0.02)K(0.01)Fe2+(0.01)]Σ=3.02[Fe3 + 1.25Al0.45Ti0.15Fe2+0.07Mg0.04V3+0.01Mn2+0.01]Σ=2.98Si2.43O9.72(OH)2.28 was identified within intensely altered and weathered pyroclastic rocks in the Sierra de Bahoruco region in the Dominican Republic. It forms small isolated euhedral crystals, infillings of fissures and fractures, and large polycrystalline aggregates, in close paragenesis with clinochlore and calcite. Other phases present in the secondary assemblage, formed as a result of hydrothermal and/or supergenic processes, include prehnite, pumpellyite, and natrolite. The formation of this secondary assemblage was a result of metasomatism under low temperature zeolite facies conditions. The formation of hydrous garnet required high-pH aqueous fluids enriched in Ca and Fe. The Ca needed for garnet crystallization might have derived from primary calcic plagioclases, diopside, and Eocene-Miocene limestones overlying the Cretaceous magmatic complex. Geothermometry on coexisting chlorite revealed that the metasomatic hydrous andradite was formed under low-temperature conditions (∼160 °C). Iron and Ti oxidation states in the andradite indicate that its formation occurred under relatively oxidizing conditions. The hydrous titanian garnet represents one of the latest phases of the pervasive calcium metasomatic event in the Sierra de Bahoruco area.

Effect of polyethylene microplastics on anammox sludge characteristics and microbial communities

Microplastics (MPs), a class of emerging pollutants, pose significant potential risks to microbial metabolism and ecology. By adding different concentration gradients of polyethylene (PE), the effects of PE on the nitrogen removal efficiency and bacterial colony structure of anammox granular sludge (AnGS) were examined. The results of the 40 d experiment with various concentrations (0.05~1.0g/L) of PE MPs on AnGS showed that the elimination of ammonia and nitrite nitrogen was less affected than in the control group. Analysis of extracellular polymer (EPS) content revealed a decreasing trend in EPS content under high stress concentrations (0.2~1.0g/L) compared to the control, and protein/polysaccharide (PN/PS) showed a similar situation, suggesting that the stability of AnGS was compromised by elevated PE concentrations. Specific anammox activity (SAA) indicated a declining trend with increasing polyethylene microplastic (PE MP) concentrations between 0.2 and 1.0g/L, and the nitrogen removal performance of AnGS decreased. From the micro-morphological point of view, the AnGS subjected to 0.5g/L stress formed blocky large particle aggregates. PE MPs were adsorbed on the surface of AnGS and combined with it to form dense particles, and both particle size and mechanical strength of the granular sludge increased proportionally the concentration of PE MPs. High-throughput sequencing data indicated that exposure to 0.5g/L PE MPs stress enhanced the complexity of the microbial community structure in AnGS, while reduced the relative abundance of the anammox bacteria Candidatus Brocadia and Planctomycetes by 2.2% and 4.2%, respectively.

Cadmium distribution and availability in different particle-size aggregates of post-harvest paddy soil amended with bio-based materials

Research on the use of organic materials as soil amendments for the remediation of Cd-contaminated agricultural land exists. However, the mechanisms based on which organic materials affect the distribution and availability of Cd in soil aggregates remain unclear. Here, Cd-contaminated paddy soil and different bio-based materials were used for rice pot experiments. Rhizosphere soils were separated into six particle sizes. Cd fractions were analyzed with BCR sequential extraction and specific functional groups associated with Cd were characterized using XPS. We found that bio-based materials promoted the formation of large aggregates to different extents. Cd tended to be enriched in fine- and coarse-grained soil particles, which is mainly related to the soil organic matter. Bio-based materials reduced the relative content of the weak-acid extractable fraction and increased the relative content of the reducible fraction, resulting in soil Cd immobilization. Soil dissolved organic matter (DOM) was the key factor affecting the distribution and availability of Cd in soil aggregates and different organic matter and Cd-binding functional groups in aggregates altered the Cd availability in soil. The results provide insight and guidance for understanding the cadmium immobilization mechanism and screening appropriate materials in the remediation of agricultural land.

Resolution of acute inflammation induced by monosodium urate crystals (MSU) through neutrophil extracellular trap-MSU aggregate-mediated negative signaling

BackgroundPolymorphonuclear neutrophils (PMN) activation by monosodium urate crystals (MSU) is crucial to acute gouty arthritis and subsequent spontaneous remission within 7–10 days. Activated PMNs release neutrophil extracellular traps (NETs) that entrap MSU crystals, forming NET-MSU aggregates. Whether NET-MSU aggregates contribute to the resolution of acute inflammation remains to be elucidated. This study uses a cell-based approach to unveil their molecular bases.MethodsAll-trans retinoic acid-differentiated HL-60 cells (dHL-60) served as surrogate PMNs. NET release from MSU-activated dHL-60 was confirmed by detecting DNA, neutrophil elastase, and citrullinated histone 3, forming large NET-MSU aggregates. NET area was measured with Fiji software after SYTOX Green staining. Released pro-inflammatory cytokines IL-8 and TNF-α, and the anti-inflammatory cytokine IL-1RA in culture supernatants were quantified to calculate the estimate inflammation score (EIS). Cellular redox state was determined by a FRET-based sensor. Expression of intracellular positive (ERK1/2) and negative (SHP-1 and SHIP-1) cytokine signaling regulators was detected by western blot. qPCR detected mRNA expressions of CISH and SOCS1–SOCS7. Flow cytometry measured neutrophil N1 (CD54) and N2 (CD182) surface markers after staining with fluorescent-conjugated antibodies.ResultsIncubating dHL-60 with MSU for 4 h maximized NET-MSU aggregate formation and acute inflammation with an EIS of 11.6. Prolonging the incubation of dHL-60 + MSU to 22 h gradually raised the EIS to 19.40 without increasing NET area, due to reduced cellular redox capacity. Adding both new dHL-60 and new MSU crystals to the culture, mimicking the clinical scenario, increased NET area but conversely suppressed EIS to 1.53, indicating acute inflammation resolution. The resolution of acute inflammation following prolonged incubation was attributed to decreases in P-ERK and increases in P-SHP-1, SOCS2, SOCS3, and CISH gene expressions, which may suppress pro-inflammatory and enhance anti-inflammatory cytokine production. Moreover, the large NET-MSU aggregates facilitated N1 to N2 polarization, crucial for accelerating inflammation resolution.ConclusionWe explored the potential molecular basis for the spontaneous resolution of MSU induced acute inflammation using a cell-based model in that huge NET-MSU aggregates frustrate the transformation of newly entering PMNs to the N2 phenotype, enhancing the production of the anti-inflammatory cytokine IL-1RA.

UNLEASH: Ultralow Nanocluster Loading of Pt via Electro-Acoustic Seasoning of Heterocatalysts.

The shift toward sustainable energy has fueled the development of advanced electrocatalysts to enable green fuel production and chemical synthesis. To date, no material outperforms Pt-group catalysts for key electrocatalytic reactions, necessitating advanced catalysts that minimize use of these rare and expensive constituents (i.e., Pt) to reduce cost without sacrificing activity. Whilst a myriad of routes involving co-synthesis of Pt with other elements have been reported, the Pt is often buried within the bulk of the composite, rendering a large proportion of it inaccessible to the interfacial electrocatalytic reaction. Surface decoration of Pt on arbitrary substrates is therefore desirable to maximize catalytic activity; nevertheless, Pt electrodeposition suffers from clustering and ripening effects that result in large ( ) aggregates that hinder electrocatalytic activity. Herein, an unconventional synthesis method is reported that utilizes high-frequency (10 MHz) acoustic waves to electrochemically 'season' a gold working electrode with an ultralow loading of Pt nanoclusters. The UNLEASH platform is shown to facilitate high-density dispersion of nanometer-order clusters at the bimetallic interface to enable superior atomic utilization of Pt. This is exemplified by its utility for methanol oxidation reaction (MOR), wherein a mass activity of 5.28 A is obtained, outperforming all other Au/Pt bimetallic electrocatalysts reported todate.

Balanced Miscibility and Crystallinity by 2D Acceptors Enabled Halogen-Free Solvent-Processed Organic Solar Cells to Achieve 19.28% Efficiency.

Two highly crystalline 2D acceptors, ATIC-C11 and ATIC-BO, with acenaphthene-expanded quinoxaline central cores, have been demonstrated with very different characteristics in ternary organic solar cells (OSCs). The difference in side chains induces their distinctive molecular packing mode and unique crystal structure, in which ATIC-C11 displays a 3D structure with an elliptical framework, and ATIC-BO gives a rectangular framework. Their high crystallinity contributes to organized molecular packing in ternary devices, thus low energetic disorder and suppressed energy loss. Through the analysis of morphology and carrier kinetics, it is found that ATIC-BO's strong self-aggregation and immiscibility induce large aggregates and severely impede charge transfer (CT) and dissociation. Conversely, ATIC-C11's suitable crystallinity and compatibility positively regulate the crystalline kinetics during film formation, thus forming much-ordered molecular packing and favorable phase separation size in blend films. As a result, ATIC-C11-based ternary devices achieve a high efficiency of 19.28% with potential in scalability and stability, which is the top-ranking efficiency among nonhalogenated solvent-processed OSCs. This work not only displays highly efficient and stable halogen-free solvent-processed organic photovoltaics (OPVs), but also offers a new thought for material design and selection rule on the third component in highly efficient ternary OSCs.

The Multi-State Epigenetic Pacemaker enables the identification of combinations of factors that influence DNA methylation.

Epigenetic clocks, DNA methylation-based predictive models of chronological age, are often utilized to study aging associated biology. Despite their widespread use, these methods do not account for other factors that also contribute to the variability of DNA methylation data. For example, many CpG sites show strong sex-specific or cell-type-specific patterns that likely impact the predictions of epigenetic age. To overcome these limitations, we developed a multidimensional extension of the Epigenetic Pacemaker, the Multi-state Epigenetic Pacemaker (MSEPM). We show that the MSEPM is capable of accurately modeling multiple methylation-associated factors simultaneously, while also providing site-specific models that describe the per site relationship between methylation and these factors. We utilized the MSEPM with a large aggregate cohort of blood methylation data to construct models of the effects of age-, sex-, and cell-type heterogeneity on DNA methylation. We found that these models capture a large faction of the variability at thousands of DNA methylation sites. Moreover, this approach allows us to identify sites that are primarily affected by aging and no other factors. An analysis of these sites reveals that those that lose methylation over time are enriched for CTCF transcription factor chip peaks, while those that gain methylation over time are associated with bivalent promoters of genes that are not expressed in blood. These observations suggest mechanisms that underlie age-associated methylation changes and suggest that age-associated increases in methylation may not have strong functional consequences on cell states. In conclusion, the MSEPM is capable of accurately modeling multiple methylation-associated factors, and the models produced can illuminate site-specific combinations of factors that affect methylation dynamics.

Impact of Land Use Conversion on Soil Structure and Hydropedological Functions in an Arid Region

ABSTRACTLand use conversion critically affects soil structure and associated functions. This study investigated variations in soil structure and hydropedological characteristics across different land use types, that is, uncultivated, cultivated, and abandoned land under an arid condition. Water‐stable aggregates in the uncultivated land were 15.4%–37.1% of those in the cultivated and abandoned lands at depths of 0–60 cm. Reclamation of the uncultivated land enhanced soil aggregate stability, while prolonged tillage led to the loss of binding organic matter, breakdown of large aggregates and decrease in aggregate stability. The mean weight diameter of aggregates at 0–40 cm depth in the cultivated land was 39.0% lower than in the abandoned land. The volume fraction of micropores (< 100 μm) in the cultivated soils was 3.7%–39.7% of that in the uncultivated soils, whereas macropores (> 1000 μm) was 1.4–1.8 times greater. Following the abandonment, soil pore diversity recovered and a hierarchical structure developed. In the abandoned land, the volume fraction of micropores (< 100 μm) was 2.4–18.9 times that of the cultivated lands, while macropores (> 1000 μm) constituted 81.4%–93.9% of those in the cultivated lands. The permeability and longitudinal dispersivity of soils in the cultivated land were significantly lower than in the uncultivated and abandoned lands, particularly at deeper soil layers. The increase in large pores in the abandoned land, important for water movement and solute transport, resulted in an order‐of‐magnitude rise in both permeability and longitudinal dispersivity compared with the cultivated lands. Overall, the abandoned land showed potential for rehabilitation from the perspectives of soil aggregates and pore structure. The findings may provide reference for land reclamation and management in arid regions.

Diverse effects of fluorescent labels on alpha-synuclein condensate formation during liquid-liquid phase separation.

Liquid-liquid phase separation is an emerging field of study, dedicated to understanding the mechanism and role of biomolecule assembly into membraneless organelles. One of the main methods employed in studying protein and nucleic acid droplet formation is fluorescence microscopy. Despite functioning as an excellent tool for monitoring biomolecule condensation, a few recent reports have presented possible drawbacks of using fluorescently labeled particles. It was observed that fluorescent tags could alter the process of protein liquid-liquid phase separation and even promote their aggregation. In this study, we examined the influence of three different protein labels on alpha-synuclein phase separation in vitro and determined that the changes in droplet formation were related to both the type, as well as concentration of the fluorescently tagged alpha-synuclein. Both protein-based labels (mCherry and eGFP) induced the formation of significantly larger droplets, while fluorescein-tagged alpha-synuclein generated an abundance of small condensates or noticeably inhibited the process of LLPS. The study also revealed that alpha-synuclein with protein-based labels could self-associate at much lower concentrations than its untagged counterpart, forming either large droplets or protein aggregates.

Carbon mineralization potential and nutrient dynamics in soils under vegetation types and soil depths at Luot mountain

Soil mineralization is a crucial soil process that improves soil physical properties, enhances carbon sequestration, and provides essential minerals and available nutrients for plant growth. This study was conducted at five vegetation types and soil depths at Luot mountain area, located in VNUF campus, Hanoi city. Samples were incubated in the dark at 25°C and measured at intervals of 1, 2, 5, 10, 15, 25, 35, and 40 days in the laboratory to determine C-CO2 respiration from soils. The study showed that CO2 emissions were highest in topsoils and decreased with deeper soil depths. Mineralized C-CO2 decreased from Shrubs > Acacia + Native species (NS) > Pinus + NS > Native species > Control. CO2 emissions peaked early in the incubation period and then stabilized in the 40-day incubation period. Larger aggregates (≥ 5mm) decreased significantly under most vegetation types, except for Shrubs, where the reduction was minimal. Aggregate size ≥3mm increased post-incubation, notably under Pinus + NS and Native species, with smaller aggregates also increasing slightly. Organic matter content was highest in the topsoil but decreased post-incubation due to microbial C mineralization. There was an increase in soil organic matter at 10-20 cm and 20-40 cm layers after incubation, especially under Shrubs. Available nitrogen slightly increased in soils post-incubation for most vegetation types. Phosphorus content increased post-incubation, peaking under Shrubs, while potassium levels were generally poor but increased during incubation. The study found that C-CO2 mineralization was strongly associated with soil porosity and pH, suggesting that higher porosity and optimal pH enhance mineralization, with organic matter content being crucial for available nutrient cycles in soils.

Research on Vocational Regional to Development by Vocational Education

Zhejiang province of China has a large economic aggregate, optimized industrial structure, balanced regional development pattern, transformation and upgrading of industrial layout, along with excellent business environment and urban-rural integrated development. For decades, through the training of technical talents which directly meets the needs of regional economic development; deepens the cooperation between schools and enterprises, provides skilled personnel support for economic and social development, and promotes regional cooperation and foreign cooperation. Taking Zhejiang Province as an example, this paper discusses how vocational education promotes the regional economy, and analyzes the existing problems and future prospects.

Mixed Adsorption Mono- and Multilayers of ß-Lactoglobulin Fibrils and Sodium Polystyrene Sulfonate

The formation of beta-lactoglobulin (BLG)/sodium polystyrene sulfonate (PSS) complexes decelerates the change in the surface properties of the mixed solutions with the surface age and increases the steady-state dilational surface elasticity in a narrow PSS concentration range. At the same time, the changes in the surface properties are accelerated in the dispersions of BLG fibrils with and without PSS due to the influence of small peptides coexisting with fibrils. A decrease in the peptide concentration as a result of the dispersion purification leads to slower changes in the surface properties at low PSS concentrations. The increase in the polyelectrolyte concentration results in an increase in the steady-state surface elasticity due to the fibril/PSS complex formation and in very slow changes in the surface properties if the polyelectrolyte exceeds a certain critical value. The latter effect is a consequence of the formation of large aggregates and of an increase in the electrostatic adsorption barrier. The consecutive adsorption of BLG fibrils and PSS leads to the formation of regular multilayers at the liquid–gas interface. The multilayer properties change noticeably with an increase in the number of layers from four to six in agreement with previous results on the multilayers of PSS with an oppositely charged synthetic polyelectrolyte, presumably due to the heterogeneity of the first PSS layer. The dynamic elasticity of the multilayers approaches 250 mN/m, indicating that they can effectively stabilize foams and emulsions.

Reactivity of chondritic meteorites under H2-rich atmospheres: Formation of H2S.

Abstract Current models of chemical evolution during star and planetary formation rely on the presence of dust grains to act as a third body. However, they generally ignore the reactivity of the dust grains themselves. Dust grains present in the protoplanetary phase will evolve as the solar system forms and, after protoplanets have appeared, they will be constantly delivered to their surfaces in the form of large aggregates or meteorites. Chondritic meteorites are mostly unaltered samples of the dust present in the first stages of the Solar System formation, that still arrive nowadays to the surface of Earth and allow us to study the properties of the materials forming the early Solar System. These materials contain, amongst others, transition metals that can potentially act as catalysts, as well as other phases that can potentially react in different astrophysical conditions, such as FeS. In this work, we present the reactivity of chondritic meteorites under H2-rich atmospheres, particularly towards the reduction of FeS for the formation of H2S and metallic Fe during the early phases of the planetary formation. We present the obtained results on the reaction rates and the percentage of FeS available to react in the materials. Additionally, we include a computational study of the reaction mechanism and the energetics. Finally, we discuss the implications of an early formation of H2S in planetary surfaces.

Primary Modes of Northern Hemisphere Snowfall Particle Size Distributions

Abstract A comprehensive understanding of snowfall microphysics is crucial for enhancing the accuracy of remote sensing snowfall retrievals. However, variations in regional and seasonal snow particle size distributions (PSDs) contribute substantial uncertainty. Here, we examine snowfall PSDs from across the Northern Hemisphere, applying Principal Component Analysis (PCA) to disdrometer observations with the aim of identifying dominant modes of variability across varying regional climates. The PCA revealed three Empirical Orthogonal Functions (EOFs) that account for a combined 95% of the variability across the dataset, which are attributed to latent linear embeddings of snowfall intensity (EOF1), snowfall character (EOF2) and snowfall regime (EOF3). Examining point clusters with the highest combined EOF values reveals six distinct modes of variability (i.e., Principal Component [PC] groups) with unique PSD traits. These groups are then correlated with environmental factors using data from collocated vertically pointing radar, surface meteorology, and reanalysis to assist in assigning physical attributes. The first and second PC groups, linked to EOF1’s intensity embedding, are described by their PSD intercepts, snowfall rates, and reflectivity and Doppler velocity values, representing low and high intensity snowfall modes, respectively. The third and fourth PC groups, associated with EOF2’s character embedding, are defined by temperature, fall speed, and density, indicative of cold, fluffy snowfall and warm, dense snowfall, respectively. The fifth and sixth PC groups, related to EOF3’s regime embedding, are distinguished by their PSD slope, snowfall rate, and reflectivity profiles, signifying shallow, weak convective systems with small particles, and deep, stratiform snowfall events with large aggregates, respectively.

Molecular dynamics simulations unveil the aggregation patterns and salting out of polyarginines at zwitterionic POPC bilayers in solutions of various ionic strengths

This study employs molecular dynamics (MD) simulations to investigate the adsorption and aggregation behavior of simple polyarginine cell-penetrating peptides (CPPs), specifically modeled as R9 peptides, at zwitterionic phosphocholine POPC membranes under varying ionic strengths of two peptide concentrations and two concentrations of NaCl and CaCl2. The results reveal an intriguing phenomenon of R9 aggregation at the membrane, which is dependent on the ionic strength, indicating a salting-out effect. As the peptide concentration and ionic strength increase, peptide aggregation also increases, with aggregate lifetimes and sizes showing a corresponding rise, accompanied by the total decrease of adsorbed peptides at the membrane surface. Notably, in high ionic strength environments, large R9 aggregates, such as octamers, are also observed occasionally. The salting-out, typically uncommon for short positively charged peptides, is attributed to the unique properties of arginine amino acid, specifically by its side chain containing amphiphilic guanidinium (Gdm+) ion which makes both intermolecular hydrophobic like-charge Gdm+ – Gdm+ and salt-bridge Gdm+ – C-terminus interactions, where the former are increased with the ionic strength, and the latter decreased due to electrostatic screening. The aggregation behavior of R9 peptides at membranes can also be linked to their CPP translocation properties, suggesting that aggregation may aid in translocation across cellular membranes.

Influence of storage time of fermented soghurt on the changes in fat and protein biomolecules through Confocal Laser Scanning Microscopy (CLSM) under refrigeration condition

The aim of the study is to assess the significance of storage duration on fermented Soghurt (soy curd), focusing on changes in fat and protein biomolecules analyzing with CLSM, viscosity measurements, and particle size distributions under refrigerated conditions. Soghurt prepared with 1% yogurt culture (Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus) was analyzed for storage stability under refrigerated conditions for up to 15 days measuring the pH, acidity, microbial counts, viscosity, particle size distribution and scanning electron microscopy for structural analysis. Even though lactic counts were not affected significantly during the storage periods, yeast & mold counts and coliform counts were absent up to 15 days during the storage. However, the product could be stored upto 7 days under refrigeration condition (6–8 °C). During the storage period, it was observed that the viscosity of soghurt increased with increase in storage time. Particle size distribution was estimated during the entire storage periods for soghurt and it was observed that smaller particle was mostly found in the range of 3.0–50.0 µm while bigger particles were in the range of 57.0–910.0 µm. Further, larger aggregates with big particle sizes were observed during prolonged storage period. The CLSM study showed the appearance of proteins and fats being dispersed slowly during the storage due to the proteolytic and lipolytic activities of yoghurt cultures after 5 days of storage under refrigeration condition.