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Liquid–liquid phase separation plays a prominent role in the physics of life, providing the cells with various membrane-less compartments. These structures exhibit a range of material properties that, in many cases, change over time. Inspired by this, we investigate here an aqueous two-phase system formed by mixing polyethylene glycol with dextran. We modulate the material properties of the resulting dextran droplets by adding DNA that readily enters the droplets. We find a non-monotonic dependence of the physical properties of the droplets under the imposed ionic conditions. [ABSTRACT FROM AUTHOR]

Organic matter can initiate heterogeneous ice nucleation in supercooled water droplets, thereby influencing atmospheric cloud glaciation. Predicting the ice nucleation ability of organic matter-containing cloud droplets is challenging due to the unknown mechanism for templating ice. Here, we observed the presence of nanoparticles in aqueous samples of known ice-nucleating biopolymers cellulose and lignin, as well as in newly identified ice-nucleating biopolymers xylan and laminarin. Using our drop Freezing Ice Nuclei Counter (FINC), we measured the median ice nucleation temperature (T50) of xylan and of laminarin droplets of 2 μl to be −14.2 and −20.0 °C, respectively. Next, we characterized these samples using nanoparticle tracking analysis, and we detected and quantified nanoparticles with mean diameters between 132 and 267 nm. Xylan contained the largest nanoparticles and froze at higher temperatures. Xylan also dictated the freezing in a 1:1:1:1 mixture with cellulose, lignin, laminarin, and xylan. Filtration experiments down to 300 kDa with the xylan sample indicated that the presence of nanoparticles triggered freezing. Overall, only samples with mean diameters above 150 nm froze above −20 °C. Furthermore, we determined the ice-active site densities normalized to particle concentrations, surface area, and mass of the nanoparticles to show that the samples' nucleation site densities are similar to sea spray aerosols and nanometer-sized dust. The identification and characterization of xylan and laminarin as nanometer-sized ice-nucleating substances expands the growing list of organic matter capable of impacting cloud formation and thus climate. [ABSTRACT FROM AUTHOR]

We show that the reflection interference fringe (RIF) is formed on a screen far away from the microdroplets placed on a prism-based substrate, which have low contact angles and thin droplet heights, caused by the dual convex–concave profile of the droplet, not a pure convex profile. The geometric formulation shows that the interference fringes are caused by the optical path difference when the reflected rays from the upper convex profile at the droplet–air interface interfere with reflection from the lower concave profile at oblique angles lower than the critical angle. Analytic solutions are obtained for the droplet height and the contact angle out of the fringe number and the fringe radius in RIF from the geometric formulation. Furthermore, the ray tracing simulation is conducted using the custom-designed code. The geometric formulation and the ray tracing show excellent agreement with the experimental observation in the relation between the droplet height and the fringe number and the relation between the contact angle and the fringe radius. This study is remarkable as the droplet's dual profile cannot be easily observed with the existing techniques. However, the RIF technique can effectively verify the existence of a dual profile of the microdroplets in a simple setup. In this work, the RIF technique is successfully developed as a new optical diagnostic technique to determine the microdroplet features, such as the dual profile, the height, the contact angle, the inflection point, and the precursor film thickness, by simply measuring the RIF patterns on the far-field screen. [ABSTRACT FROM AUTHOR]

Lipotoxicity has been considered the main cause of pancreatic beta-cell failure during type 2 diabetes development. Lipid droplets (LD) are believed to regulate the beta-cell sensitivity to free fatty acids (FFA), but the underlying molecular mechanisms are largely unclear. Accumulating evidence points, however, to an important role of intracellular sphingosine-1-phosphate (S1P) metabolism in lipotoxicity-mediated disturbances of beta-cell function. In the present study, we compared the effects of an increased irreversible S1P degradation (S1P-lyase, SPL overexpression) with those associated with an enhanced S1P recycling (overexpression of S1P phosphatase 1, SGPP1) on LD formation and lipotoxicity in rat INS1E beta-cells. Interestingly, although both approaches led to a reduced S1P concentration, they had opposite effects on the susceptibility to FFA. Overexpression of SGPP1 prevented FFA-mediated caspase-3 activation by a mechanism involving an enhanced lipid storage capacity and prevention of oxidative stress. In contrast, SPL overexpression limited LD biogenesis, content, and size, while accelerating lipophagy. This was associated with FFA-induced hydrogen peroxide formation, mitochondrial fragmentation, and dysfunction, as well as ER stress. These changes coincided with the upregulation of proapoptotic ceramides but were independent of lipid peroxidation rate. Also in human EndoC-βH1 beta-cells, suppression of SPL with simultaneous overexpression of SGPP1 led to a similar and even more pronounced LD phenotype as that in INS1E-SGPP1 cells. Thus, intracellular S1P turnover significantly regulates LD content and size and influences beta-cell sensitivity to FFA.

Experimental findings by others suggest that OH radicals are formed in unexpected abundance on or near surfaces of 1–50 µm microdroplets comprised of pure water, but the mechanism by which these radicals are generated is not yet fully resolved. In this work, we examine two possibilities using ab initio electronic structure methods: (1) electron transfer (ET) from a microdroplet surface-bound OH− anion to a nearby H3O+ cation and (2) proton transfer (PT) from such a H3O+ cation to a nearby OH− anion. Our findings suggest that both processes are possible but only if the droplet's underlying water molecules comprising the microdroplet provide little screening of the Coulomb interaction between the anion and cation once they reach ∼10 Å of one another. In the ET event, an OH radical is formed directly; for PT, the OH formation occurs because the new O–H bond formed by the transferred proton is created at a bond length sufficiently elongated to permit homolytic cleavage. Both the ET and PT pathways predict that H atoms will also be formed. Finally, we discuss the roles played by strong local electric fields in mechanisms that have previously been proposed and that occur in our two mechanisms. [ABSTRACT FROM AUTHOR]

Several genetic risk factors for Alzheimers disease implicate genes involved in lipid metabolism and many of these lipid genes are highly expressed in glial cells1. However, the relationship between lipid metabolism in glia and Alzheimers disease pathology remains poorly understood. Through single-nucleus RNA sequencing of brain tissue in Alzheimers disease, we have identified a microglial state defined by the expression of the lipid droplet-associated enzyme ACSL1 with ACSL1-positive microglia being most abundant in patients with Alzheimers disease having the APOE4/4 genotype. In human induced pluripotent stem cell-derived microglia, fibrillar Aβ induces ACSL1 expression, triglyceride synthesis and lipid droplet accumulation in an APOE-dependent manner. Additionally, conditioned media from lipid droplet-containing microglia lead to Tau phosphorylation and neurotoxicity in an APOE-dependent manner. Our findings suggest a link between genetic risk factors for Alzheimers disease with microglial lipid droplet accumulation and neurotoxic microglia-derived factors, potentially providing therapeutic strategies for Alzheimers disease.

Airborne transmission of SARS-CoV-2 aerosol remains contentious. Importantly, whether cough or breath-generated bioaerosols can harbor viable and replicating virus remains largely unclarified. We performed size-fractionated aerosol sampling (Andersen cascade impactor) and evaluated viral culturability in human cell lines (infectiousness), viral genetics, and host immunity in ambulatory participants with COVID-19. Sixty-one percent (27/44) and 50% (22/44) of participants emitted variant-specific culture-positive aerosols  95%). There is considerable heterogeneity in potential infectiousness i.e., only 29% of participants were probably highly infectious (produced culture-positive aerosols

Effect mechanisms of the undercooling degree and the surface configuration on the ice growth characteristics were revealed under micro-droplets icing conditions. Preferential ice crystals appear firstly on the surfaces due to the randomness of icing, and obtain growth advantages to form protruding structures. Protruding structures block the incoming droplets from contacting the substrates, causing voids around the structures. The undercooling degree mainly affects the density and the growth rate of preferential ice crystals. With the increase of undercooling degree, the preferential ice crystals have higher density and growth rate, resulting in stronger growth advantage and higher porosity. The surface configuration affects the growth mode, and the ice layer grows with uniform mode, spreading mode and structure-induced mode on the aluminum, smooth Polytetrafluoroethylene (PTFE) and rough PTFE surface respectively, causing the needle-like, ridge-like and cluster-like ice crystals. The rough structures effectively improve the porosity of the ice layer, which is beneficial for optimizing the icephobic property of the materials. This paper provides important theoretical guidance for the design of subsequent icephobic materials. [ABSTRACT FROM AUTHOR]

It remains poorly understood how SARS-CoV-2 infection influences the physiological host factors important for aerosol transmission. We assessed breathing pattern, exhaled droplets, and infectious virus after infection with Alpha and Delta variants of concern (VOC) in the Syrian hamster. Both VOCs displayed a confined window of detectable airborne virus (24-48 hr), shorter than compared to oropharyngeal swabs. The loss of airborne shedding was linked to airway constriction resulting in a decrease of fine aerosols (1-10 µm) produced, which are suspected to be the major driver of airborne transmission. Male sex was associated with increased viral replication and virus shedding in the air. Next, we compared the transmission efficiency of both variants and found no significant differences. Transmission efficiency varied mostly among donors, 0-100% (including a superspreading event), and aerosol transmission over multiple chain links was representative of natural heterogeneity of exposure dose and downstream viral kinetics. Co-infection with VOCs only occurred when both viruses were shed by the same donor during an increased exposure timeframe (24-48 hr). This highlights that assessment of host and virus factors resulting in a differential exhaled particle profile is critical for understanding airborne transmission.

Adipose tissue is the site of long-term energy storage. During the fasting state, exercise, and cold exposure, the white adipose tissue mobilizes energy for peripheral tissues through lipolysis. The mobilization of lipids from white adipose tissue to the liver can lead to excess triglyceride accumulation and fatty liver disease. Although the white adipose tissue is known to release free fatty acids, a comprehensive analysis of lipids mobilized from white adipocytes in vivo has not been completed. In these studies, we provide a comprehensive quantitative analysis of the adipocyte-secreted lipidome and show that there is interorgan crosstalk with liver. Our analysis identifies multiple lipid classes released by adipocytes in response to activation of lipolysis. Time-dependent analysis of the serum lipidome showed that free fatty acids increase within 30 min of β3-adrenergic receptor activation and subsequently decrease, followed by a rise in serum triglycerides, liver triglycerides, and several ceramide species. The triglyceride composition of liver is enriched for linoleic acid despite higher concentrations of palmitate in the blood. To further validate that these findings were a specific consequence of lipolysis, we generated mice with conditional deletion of adipose tissue triglyceride lipase exclusively in adipocytes. This loss of in vivo adipocyte lipolysis prevented the rise in serum free fatty acids and hepatic triglycerides. Furthermore, conditioned media from adipocytes promotes lipid remodeling in hepatocytes with concomitant changes in genes/pathways mediating lipid utilization. Together, these data highlight critical role of adipocyte lipolysis in interorgan crosstalk between adipocytes and liver.

Recent studies in brown adipose tissue (BAT) described a unique subpopulation of mitochondria bound to lipid droplets (LDs), which were termed PeriDroplet Mitochondria (PDM). PDM can be isolated from BAT by differential centrifugation and salt washes. Contrary to BAT, this approach has so far not led to the successful isolation of PDM from white adipose tissue (WAT). Here, we developed a method to isolate PDM from WAT with high yield and purity by an optimized proteolytic treatment that preserves the respiratory function of mitochondria. Using this approach, we show that, contrary to BAT, WAT PDM have lower respiratory and ATP synthesis capacities compared with WAT cytoplasmic mitochondria (CM). Furthermore, by isolating PDM from LDs of different sizes, we found a negative correlation between LD size and the respiratory capacity of their PDM in WAT. Thus, our new isolation method reveals tissue-specific characteristics of PDM and establishes the existence of heterogeneity in PDM function determined by LD size.

Adipose tissue stores triacylglycerol (TAG) in lipid droplets (LD) and release fatty acids upon lipolysis during energy shortage. We identify ApoL6 as a LD-associated protein mainly found in adipose tissue, specifically in adipocytes. ApoL6 expression is low during fasting but induced upon feeding. ApoL6 knockdown results in smaller LD with lower TAG content in adipocytes, while ApoL6 overexpression causes larger LD with higher TAG content. We show that the ApoL6 affects adipocytes through inhibition of lipolysis. While ApoL6, Perilipin 1 (Plin1), and HSL can form a complex on LD, C-terminal ApoL6 directly interacts with N-terminal Plin1 to prevent Plin1 binding to HSL, to inhibit lipolysis. Thus, ApoL6 ablation decreases white adipose tissue mass, protecting mice from diet-induced obesity, while ApoL6 overexpression in adipose brings obesity and insulin resistance, making ApoL6 a potential future target against obesity and diabetes.

Toxoplasma gondii resides in its intracellular niche by employing a series of specialized secretory organelles that play roles in invasion, host cell manipulation, and parasite replication. Rab GTPases are major regulators of the parasite's secretory traffic that function as nucleotide-dependent molecular switches to control vesicle trafficking. While many of the Rab proteins have been characterized in T. gondii, precisely how these Rabs are regulated remains poorly understood. To better understand the parasite's secretory traffic, we investigated the entire family of Tre2-Bub2-Cdc16 (TBC) domain-containing proteins, which are known to be involved in vesicle fusion and secretory protein trafficking. We first determined the localization of all 18 TBC domain-containing proteins to discrete regions of the secretory pathway or other vesicles in the parasite. Second, we use an auxin-inducible degron approach to demonstrate that the protozoan-specific TgTBC9 protein, which localizes to the endoplasmic reticulum (ER), is essential for parasite survival. Knockdown of TgTBC9 results in parasite growth arrest and affects the organization of the ER and mitochondrial morphology. TgTBC9 knockdown also results in the formation of large lipid droplets (LDs) and multi-membranous structures surrounded by ER membranes, further indicating a disruption of ER functions. We show that the conserved dual-finger active site in the TBC domain of the protein is critical for its GTPase-activating protein (GAP) function and that the Plasmodium falciparum orthologue of TgTBC9 can rescue the lethal knockdown. We additionally show by immunoprecipitation and yeast 2 hybrid analyses that TgTBC9 preferentially binds Rab2, indicating that the TBC9-Rab2 pair controls ER morphology and vesicular trafficking in the parasite. Together, these studies identify the first essential TBC protein described in any protozoan and provide new insight into intracellular vesicle trafficking in T. gondii.

In the present work we revisit the problem of the quantum droplet in atomic Bose–Einstein condensates with an eye towards describing its ground state in the large density, so-called Thomas–Fermi (TF) limit. We consider the problem as being separable into 3 distinct regions: an inner one, where the TF approximation is valid, a sharp transition region where the density abruptly drops towards the (vanishing) background value and an outer region which asymptotes to the background value. We analyze the spatial extent of each of these regions, and develop a systematic effective description of the rapid intermediate transition region. Accordingly, we derive a uniformly valid description of the ground state that is found to accurately match our numerical computations. As an additional application of our considerations, we show that this formulation allows for an analytical approximation of excited states such as the (trapped) dark soliton in the large density limit. [ABSTRACT FROM AUTHOR]

A catalyst-free method was developed for the ring opening of azlactones (also known as oxazolones) in water microdroplets. Azlactone was dissolved in a water : acetonitrile (1 : 1) mixture, and the solution is sprayed by using nitrogen gas at a pressure of 120 psi to generate microdroplets. This method promoted selective cleavage of the lactone bond to afford the corresponding N-benzoyl derivatives in up to 94% isolated yield with no epimerization. Our method produces the ring-opening products in milliseconds (up to 94 μmol for 33.3 minutes), and may have utility for high-throughput synthesis applications. [ABSTRACT FROM AUTHOR]

Recent research on a special type of sexual reproduction and zygospore formation in Zygnematophyceae, the sister group of land plants, is summarized. Within this group, gamete fusion occurs by conjugation. Zygospore development in Mougeotia, Spirogyra and Zygnema is highlighted, which has recently been studied using Raman spectroscopy, allowing chemical imaging and detection of changes in starch and lipid accumulation. Three-dimensional reconstructions after serial block-face scanning electron microscopy (SBF-SEM) or focused ion beam SEM (FIB-SEM) made it possible to visualize and quantify cell wall and organelle changes during zygospore development. The zygospore walls undergo strong modifications starting from uniform thin cell walls to a multilayered structure. The mature cell wall is composed of a cellulosic endospore and exospore and a central mesospore built up by aromatic compounds. In Spirogyra, the exospore and endospore consist of thick layers of helicoidally arranged cellulose fibrils, which are otherwise only known from stone cells of land plants. While starch is degraded during maturation, providing building blocks for cell wall formation, lipid droplets accumulate and fill large parts of the ripe zygospores, similar to spores and seeds of land plants. Overall, data show similarities between streptophyte algae and embryophytes, suggesting that the genetic toolkit for many land plant traits already existed in their shared algal ancestor. This article is part of the theme issue 'The evolution of plant metabolism'. [ABSTRACT FROM AUTHOR]

Purpose: The COVID-19 pandemic has affected lives and dental treatment. Aerosols and droplets generated during dental treatment present a risk of infection for dental care workers. However, detailed elucidation of the conditions under which those are generated has yet to be presented, and no clear countermeasures for protection have been established. The present study aimed to clarify the process of generation of aerosol and droplets in dental treatment, as well as their dynamics for establishment of effective countermeasures and protection strategies. Methods: Images were obtained using a high-speed camera of aerosol and droplets generated during dental treatments performed on a mannequin. The effects of intraoral vacuum and extraoral vacuum to reduce those, as well as splash range with different body position were examined. Quantitative evaluations of aerosol and droplets were also performed using water-sensitive paper. Results: Aerosol and droplets quantities were significantly reduced by use of both intraoral and extraoral vacuums as compared to no vacuum in both image analysis and findings obtained with water-sensitive paper (p < 0.05). Additionally, the intensity of aerosol and droplets when using the intraoral and extraoral vacuum devices with a body position of 45 degrees was a significantly less as compared to the other settings (p < 0.001). Conclusions: The present study demonstrated the effectiveness of visualization of the aerosol and droplets generated by dental tools using a high-speed camera. Use of an extraoral vacuum resulted in a reduction of those generated during simulated dental treatment, and also contributed to diffusion prevention to protect the operator and assistant. Nevertheless, it is necessary to be careful because the use of extraoral vacuums may reverse the spread of aerosol and droplets depending on the position of patient. [ABSTRACT FROM AUTHOR]

Background: Lung adenocarcinoma (LUAD) is one of the most common malignant tumors. Although several treatments have been proposed, the long-term prognosis of this cancer is poor. Lipid droplets and mitochondria are important organelles that regulate energy metabolism in cells and are postulated to promote the occurrence and progression of tumors. However, few risk prediction models have been constructed based on lipid drop-mitochondria-related genes (LMRGs). Methods: In this study, we constructed a lipid drop-mitochondrial (LD-M) risk score model based on data from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. Biological functions and clinical benefits associated with the various risk scores were analyzed using R software, GraphPad Prism 9, and the online database system. Results: An LD-M risk score model comprising ABLIM3, AK4, CAV2, CPS1, CYP24A1, DLGAP5, FGR, and SH3BP5, was developed and its predictive power was validated. The risk score was closely associated with the cell cycle. Immunophenoscore (IPS) and Tumor immune dysfunction and exclusion (TIDE) results demonstrated that the low-risk group was more sensitive to immunotherapy. Drug sensitivity analysis indicated that BMS-754807, ZM447439, SB216763, and other drugs had lower IC50 values in the low-risk group. Conclusion: Our results suggest that the LD-M risk score is an effective prognostic indicator for individualized treatment of LUAD. [ABSTRACT FROM AUTHOR]

High resolution extended‐range cloud condensation nuclei (CCN) spectral comparisons with cloud microphysics and drizzle of the Physics of Stratocumulus Tops (POST) field experiment confirmed results in the Marine Stratus/Stratocumulus Experiment (MASE). Both of these stratus cloud projects demonstrated that bimodal CCN spectra typically caused by cloud processing were associated with clouds that exhibited higher concentrations of smaller droplets with narrower distributions and less drizzle than clouds associated with unimodal CCN spectra. Resulting brighter clouds and increased cloudiness could enhance both indirect aerosol effects (IAE). These stratus findings are opposite of analogous measurements in two cumulus cloud projects, which showed bimodal CCN associated with fewer larger droplets more broadly distributed and with more drizzle than clouds associated with unimodal CCN. Resulting reduced cumulus brightness and cloudiness could reduce both IAE. Physics of Stratocumulus Tops (POST) flights in air masses with higher CCN concentrations, NCCN, showed more extremes of the stratus characteristics. However, POST flights with lower NCCN showed opposite droplet characteristics similar to the cumulus clouds, yet still showed less drizzle in clouds associated with bimodal CCN, but not as much less as the flights with higher NCCN. Since all MASE clouds were in polluted air masses, while the two cumulus projects were in clean air masses we deduce from these four projects that both the dynamic stratus/cumulus differences (vertical wind) and NCCN are responsible for the microphysics and drizzle differences among these projects. This is because the clean POST characteristics are a hybrid between MASE/POST high NCCN and the two cumulus projects. Plain Language Summary: The Physics of Stratocumulus Tops (POST) project displayed relationships between the particles that cloud droplets condense upon (cloud condensation nuclei; CCN) and cloud and drizzle drop concentrations that are consistent with those in the Marine Stratus/Stratocumulus Experiment (MASE). CCN spectra composed of two separate modes that are often caused by chemical and physical process mechanisms within the clouds were associated with clouds that had greater concentrations of smaller droplets and less drizzle than clouds associated with single mode (unimodal) CCN spectra. These findings are opposite of analogous analyses of two cumulus cloud projects. However, a subset of POST clouds in cleaner air showed bimodal CCN associated with clouds that had fewer but larger droplets yet still less drizzle than clouds associated with unimodal CCN. These clean stratus results are thus similar to the cumulus findings with respect to cloud droplets but opposite of the cumulus drizzle findings. Therefore, throughout POST bimodal CCN were associated with clouds that contained less drizzle than clouds associated with unimodal CCN. However, the apparent bimodal CCN drizzle suppression was less in the cleaner POST clouds. Key Points: In two stratus cloud projects bimodal cloud condensation nuclei (CCN) spectra are associated with clouds that have more droplets with smaller sizes and less drizzleHowever, in cleaner Physics of Stratocumulus Tops stratus clouds bimodal CCN spectra are associated with fewer but larger droplets yet also less drizzleThese findings suggest that cloud processing of aerosol could enhance the indirect aerosol effect (IAE) in stratus, especially 2nd IAE [ABSTRACT FROM AUTHOR]

Hypervirulent Klebsiella pneumoniae (hvKp), an emerging Kp subtype, has become a serious global pathogen. However, the information regarding host interactions and innate immune responses during hvKp infection is limited. Here, we found that hvKp clinical strains increased triacylglycerol synthesis, resulting in lipid droplets (LDs) formation via the mammalian target of rapamycin signaling pathway in RAW264.7 cells. Treatment with rapamycin, an inhibitor of this pathway, affected LDs formation and antimicrobial responses against clinical hvKp infections. In accordance with the role of LDs in modulating inflammation, the pharmacological inhibition of lipogenesis reduced proinflammatory cytokine expression during hvKp infections. In addition, inhibition of LDs formation using pharmacological inhibitors and knockdown of lipogenesis regulators decreased the intracellular survival of hvKp in macrophages. Moreover, inhibiting LDs biogenesis reduced mortality, weight loss, and bacterial loads in hvKp-infected mice. Collectively, these data suggest that LDs biogenesis is crucial in linking host immune responses to clinical hvKp infections. [ABSTRACT FROM AUTHOR]

The ability of anthropogenic aerosols to freeze supercooled cloud droplets remains debated. In this work, we present observational evidence for the glaciation of supercooled liquid-water clouds at industrial aerosol hot spots at temperatures between −10° and −24°C. Compared with the nearby liquid-water clouds, shortwave reflectance was reduced by 14% and longwave radiance was increased by 4% in the glaciation-affected regions. There was an 8% reduction in cloud cover and an 18% reduction in cloud optical thickness. Additionally, daily glaciation-induced snowfall accumulations reached 15 millimeters. Glaciation events downwind of industrial aerosol hot spots indicate that anthropogenic aerosols likely serve as ice-nucleating particles. However, rare glaciation events downwind of nuclear power plants indicate that factors other than aerosol emissions may also play a role in the observed glaciation events. [ABSTRACT FROM AUTHOR]

Group 2 innate lymphoid cells (ILC2s) play a crucial role in allergic diseases by coordinating a complex network of various effector cell lineages involved in type 2 inflammation. However, their function in regulating airway neutrophil infiltration, a deleterious symptom of severe asthma, remains unknown. Here, we observed ILC2-dependent neutrophil accumulation in the bronchoalveolar lavage fluid (BALF) of allergic mouse models. Chromatography followed by proteomics analysis identified the alarmin high mobility group box-1 (HMGB1) in the supernatant of lung ILC2s initiated neutrophil chemotaxis. Genetic perturbation of Hmgb1 in ILC2s reduced BALF neutrophil numbers and alleviated airway inflammation. HMGB1 was loaded onto the membrane of lipid droplets (LDs) released from activated lung ILC2s. Genetic inhibition of LD accumulation in ILC2s significantly decreased extracellular HMGB1 abundance and BALF neutrophil infiltration. These findings unveil a previously uncharacterized extracellular LD-mediated immune signaling delivery pathway by which ILC2s regulate airway neutrophil infiltration during allergic inflammation. [Display omitted] • ILC2s induce airway neutrophil infiltration in asthma models • Alarmin HMGB1 secreted from ILC2s activates a neutrophil chemotaxis program • ILC2s release HMGB1-loaded lipid droplets into the extracellular milieu • Lipid droplets facilitate the intercellular delivery of alarmin signaling Whether and how ILC2s regulate airway neutrophil infiltration during asthma is unknown. Rao et al. show that ILC2s release HMGB1-loaded lipid droplets to induce neutrophil infiltration into the airway, demonstrating the crucial functions of extracellular lipid droplets in driving the pathogenic responses of ILC2s and allergic inflammation. [ABSTRACT FROM AUTHOR]

Microglia are critically involved in post‐stroke inflammation affecting neurological outcomes. Lipid droplet (LD) accumulation in microglia results in a dysfunctional and pro‐inflammatory state in the aged brain and worsens the outcome of neuroinflammatory and neurodegenerative diseases. However, the role of LD‐rich microglia (LDRM) under stroke conditions is unknown. Using in vitro and in vivo stroke models, herein accumulation patterns of microglial LD and their corresponding microglial inflammatory signaling cascades are studied. Interactions between temporal and spatial dynamics of lipid profiles and microglial phenotypes in different post‐stroke brain regions are found. Hence, microglia display enhanced levels of LD accumulation and elevated perilipin 2 (PLIN2) expression patterns when exposed to hypoxia or stroke. Such LDRM exhibit high levels of TNF‐α, IL‐6, and IL‐1β as well as a pro‐inflammatory phenotype and differentially expressed lipid metabolism‐related genes. These post‐ischemic alterations result in distinct lipid profiles with spatial and temporal dynamics, especially with regard to cholesteryl ester and triacylglycerol levels, further exacerbating post‐ischemic inflammation. The present study sheds new light on the dynamic changes of brain lipid profiles and aggregation patterns of LD in microglia exposed to ischemia, demonstrating a mutual mechanism between microglial phenotype and function, which contributes to progression of brain injury. [ABSTRACT FROM AUTHOR]

Group 2 Innate Lymphoid Cells (ILC2) are critical drivers of both innate and adaptive type 2 immune responses, known to orchestrate processes involved in tissue restoration and wound healing. In addition, ILC2 have been implicated in chronic inflammatory barrier disorders in type 2 immunopathologies such as allergic rhinitis and asthma. ILC2 in the context of allergen-driven airway inflammation have recently been shown to influence local and systemic metabolism, as well as being rich in lipid-storing organelles called lipid droplets. However, mechanisms of ILC2 lipid anabolism and catabolism remain largely unknown and the impact of these metabolic processes in regulating ILC2 phenotypes and effector functions has not been extensively characterized. ILC2 phenotypes and effector functions are shaped by their metabolic status, and determining the metabolic requirements of ILC2 is critical in understanding their role in type 2 immune responses and their associated pathophysiology. We detail here a novel experimental method of implementing flow cytometry for large scale analysis of fatty acid uptake, storage of neutral lipids, and fatty acid oxidation in primary murine ILC2 with complementary morphological analysis of lipid storage using confocal microscopy. By combining flow cytometry and confocal microscopy, we can identify the metabolic lipid requirements for ILC2 functions as well as characterize the phenotype of lipid storage in ILC2. Linking lipid metabolism pathways to ILC2 phenotypes and effector functions is critical for the assessment of novel pharmaceutical strategies to regulate ILC2 functions in type 2 immunopathologies. [ABSTRACT FROM AUTHOR]

Ferroptosis is a regulated cell death driven by iron-dependent lipid peroxidation and associated with drug resistance in lung adenocarcinoma (LUAD). It's found that aldehyde dehydrogenase 2 (ALDH2), which is highly mutated in East Asian populations, is correlated with response to chemotherapy in LUAD patients. The rs671 variant knock-in, downregulation, and pharmacological inhibition of ALDH2 render LUAD cells more vulnerable to ferroptosis inducers and platinum-based chemotherapy. ALDH2 inhibits ferroptosis through the detoxification of 4-hydroxynonenal and malondialdehyde, the product of lipid peroxidation, as well as the production of NADH at the same time. Besides, ALDH2 deficiency leads to elevated intracellular pH (pHi), thus inhibiting the ERK/CREB1/GPX4 axis. Interestingly, ALDH2 is also regulated by CREB1, and the ALDH2 enzyme activity was decreased with elevated pHi. What's more, the elevated pHi caused by impaired ALDH2 activity promotes the biosynthesis of lipid droplets to counteract ferroptosis. At last, the effect of ALDH2 on ferroptosis and chemosensitivity is confirmed in patient-derived organoids and xenograft models. Collectively, this study demonstrates that ALDH2 deficiency confers sensitivity to platinum through ferroptosis in LUAD, and targeting ALDH2 is a promising new strategy to enhance the sensitivity of platinum-based chemotherapy for the treatment of LUAD patients. [Display omitted] • ALDH2 rs671 polymorphism is common in the Asian population. • ALDH2 deficiency renders lung adenocarcinoma (LUAD) more vulnerable to platinum via ferroptosis. • ALDH2 counteracts ferroptosis in a pH-dependent manner. • ALDH2 is a promising target for overcoming chemoresistance in LUAD patients. [ABSTRACT FROM AUTHOR]

In this paper, LD-TCF, a targeting probe for lipid droplets (LDs) with a near-infrared emission wavelength and large Stokes shift, was fabricated for polarity detection by assembling a donor–π–acceptor (D–π–A) molecule with typical twisted intramolecular charge transfer (TICT) characteristics. Surprisingly, the fluorescence emission wavelength of the newly constructed probe LD-TCF was stretched to 703 nm, and the Stokes shift was amplified to 126 nm. Furthermore, LD-TCF could specifically answer the change in polarity efficiently and did not experience interference from other biologically active materials. Importantly, LD-TCF exhibited the ability to target lipid droplets, providing valuable insights for the early diagnosis and tracking of pathophysiological processes underlying LD polarity. [ABSTRACT FROM AUTHOR]

Background: The earliest manifestation of alcohol‐associated liver disease (ALD) is steatosis characterized by deposition of fat in specialized organelles called lipid droplets (LDs). While alcohol administration causes a rise in LD numbers in the hepatocytes, little is known regarding their characteristics that allow their accumulation and size to increase. The aim of the present study is to gain insights into underlying pathophysiological mechanisms by investigating the ethanol‐induced changes in hepatic LD proteome as a function of LD size. Methods: Adult male Wistar rats (180–200 g BW) were fed with ethanol liquid diet for 6 weeks. At sacrifice, large‐, medium‐, and small‐sized hepatic LD subpopulations (LD1, LD2, and LD3, respectively) were isolated and subjected to morphological and proteomic analyses. Results: Morphological analysis of LD1‐LD3 fractions of ethanol‐fed rats clearly demonstrated that LD1 contained larger LDs compared with LD2 and LD3 fractions. Our preliminary results from principal component analysis showed that the proteome of different‐sized hepatic LD fractions was distinctly different. Proteomic data analysis identified over 2000 proteins in each LD fraction with significant alterations in protein abundance among the three LD fractions. Among the altered proteins, several were related to fat metabolism, including synthesis, incorporation of fatty acid, and lipolysis. Ingenuity pathway analysis revealed increased fatty acid synthesis, fatty acid incorporation, LD fusion, and reduced lipolysis in LD1 compared to LD3. Overall, the proteomic findings indicate that the increased level of protein that facilitates fusion of LDs combined with an increased association of negative regulators of lipolysis dictates the generation of large‐sized LDs during the development of alcohol‐associated hepatic steatosis. Conclusion: Several significantly altered proteins were identified in different‐sized LDs isolated from livers of ethanol‐fed rats. Ethanol‐induced increases in specific proteins that hinder LD lipid metabolism led to the accumulation and persistence of large‐sized LDs in the liver. [ABSTRACT FROM AUTHOR]

In the parent, gestational diabetes mellitus (GDM) causes both hyperglycemia and hyperlipidemia. Despite excess lipid availability, infants exposed to GDM are at risk for essential long-chain polyunsaturated fatty acid (LCPUFA) deficiency. Isotope studies have confirmed less LCPUFA transfer from the parent to the fetus, but how diabetic fuels impact placental fatty acid (FA) uptake and lipid droplet partitioning is not well-understood. We evaluated the effects of high glucose conditions, high lipid conditions, and their combination on trophoblast growth, viability, mitochondrial bioenergetics, BODIPY-labeled fatty acid (FA) uptake, and lipid droplet dynamics. The addition of four carbons or one double bond to FA acyl chains dramatically affected the uptake in both BeWo and primary isolated cytotrophoblasts (CTBs). The uptake was further impacted by media exposure. The combination-exposed trophoblasts had more mitochondrial protein (p = 0.01), but impaired maximal and spare respiratory capacities (p < 0.001 and p < 0.0001), as well as lower viability (p = 0.004), due to apoptosis. The combination-exposed trophoblasts had unimpaired uptake of BODIPY C12 but had significantly less whole-cell and lipid droplet uptake of BODIPY C16, with an altered lipid droplet count, area, and subcellular localization, whereas these differences were not seen with individual high glucose or lipid exposure. These findings bring us closer to understanding how GDM perturbs active FA transport to increase the risk of adverse outcomes from placental and neonatal lipid accumulation alongside LCPUFA deficiency. [ABSTRACT FROM AUTHOR]

Plasma‐activated mist (PAM) has seen increasingly widespread applications in areas such as surface disinfection and fog cultivation. The high‐resolution time diagnostics of ns pulse plasma interacting with micron‐sized droplets under high‐humidity conditions is challenging to achieve with existing experimental methods. This paper employs a global model to study the interaction between plasma and droplets, offering a detailed analysis of the plasma's transition from the gas phase to the liquid phase. It was discovered that in high‐humidity environments, hydrated ions become the predominant ion species. These acidic active substances in PAM droplets are the primary factors in the mist's ability to kill bacteria. The paper further examines how variations in droplet size and discharge voltage influence the PAM's activity. [ABSTRACT FROM AUTHOR]

Airframe icing caused by interactions with supercooled cloud droplets and precipitation can pose a risk to aviation operations and life safety. The In-Cloud Icing and Large-drop Experiment (ICICLE) was conducted in January–March 2019 to capture measurements in freezing conditions in support of the Federal Aviation Administration (FAA) Terminal Area Icing Weather Information for NextGen (TAIWIN) program. The National Research Council of Canada's Convair-580 research aircraft fulfilled the airborne data collection requirements for the ICICLE campaign and sampled icing clouds and atmospheric conditions over the midwestern United States. ICICLE flight 18, conducted on 17 February 2019, collected cloud and precipitation measurements during a widespread storm that generated supercooled small drops and freezing drizzle (FZDZ) within both liquid and mixed-phase regions. Supercooled liquid water content (LWC) typically ranged 0.30–0.45 g m−3 and exceeded 0.70 g m−3 in one instance. Maximum FZDZ diameters of 300–400 μm were commonly sampled near the base of clouds. Missed approaches performed at four Illinois airfields provided measurements of conditions from near ground level to above cloud top and supplied information regarding FZDZ formation and evolution. FZDZ was found to form at altitudes featuring relatively high LWC and sufficiently low droplet number concentrations. FZDZ formation zones were sometimes collocated with regions of atmospheric instability and/or wind shear. Flight through highly variable supercooled cloud droplet and FZDZ conditions resulted in significant Convair-580 airframe icing, highlighting the risk that icing conditions can pose to aircraft safety. [ABSTRACT FROM AUTHOR]

Intensified by climate change, extreme rainfall events are frequently increasing and have become severe particularly in tropical and subtropical regions. On 16 April 2024, the United Arab Emirates (UAE) experienced a record-breaking flood event, characterized by ~ 250 mm of rain within a 24-hour period and surpassed the previous record of 1949. Later, on 2 May 2024, another rainfall event occurred but with low rainfall (~20 mm in 12 hours). These consecutive incidents raised a need to understand convective mechanism, so present study focus to analyse it using various cloud properties over Dubai. Our findings inferred that the April event was mostly driven by extensive cloud such as cumulonimbus which stretched up to ~ 16 km, with prominent features of high optical thickness (~150), small-sized cloud droplets (~23.89 µm), and considerable liquid water content (~2185 g/m−2). Further, we found high (~400–1800 J kg−1) and comparatively low (~0–700 J kg−1) potential energies, which trigerred convection on April 16 and May 02 respectively. Thus our study gained insights related to occurrence of convective activities at regional level using atmospheric and cloud parameters. These outcomes can be used as an input in climate models to improve weather patterns even in arid environments like Dubai, where cloud seeding is a regular practice. [ABSTRACT FROM AUTHOR]

Lipid metabolism during curing of meat products is an essential biological process that affects their eating quality. Lipid droplets (LDs) are the main sites for storing neutral lipids and participating in lipid metabolism, and their surface lipid droplet-related proteins (LDRPs) directly regulate lipid degradation. In this study, we analyzed the expression changes of LDRPs in porcine biceps femoris muscle under curing conditions (1% and 3% salt concentration) by proteomics and discussed the role played by LDs in the regulation of lipid metabolism. A total of 1127 quantitative proteins were identified by mass spectrometry. Among them, the differential proteins between the control and cured groups were mainly involved in biological processes such as lipid metabolism and carbohydrate metabolism. Protein quantification results showed that RAB18 expression was downregulated after curing, suggesting that curing caused LDs to become small and dispersed. Besides, the expression trends of proteins responsible for macroautophagy (RAB7 and RAB10) and those responsible for CMA (HSPA8 and PLIN2) in LDs were opposite. The upregulation of CPT2, ACADL, FABP4, and FABP5, which were related to fatty acid transport and β-oxidation, intensified the degradation of fatty acid in cured samples. Consequently, we concluded that curing promoted LD degradation. Macroautophagy, CMA, and lipolysis were likely to occur alternately and synergistically during the degradation process. The results have significant implications for our understanding of the metabolic processes involved in lipid molecules during meat processing. [ABSTRACT FROM AUTHOR]

The pinning dynamic of oil droplet on micropore surface has a significant impact on the stability of the oil film. Herein, the numerical model of the oil droplet generated in situ at the orifices is established. The influence of pore parameters and the inlet pressure on the movement of the three‐phase contact line are explored. The transformation mechanism between pinning and spreading of the droplet is revealed. The result shows that due to the competition between the surface tension and the driving force, the flow field parameters at the pinning point become unstable. Until the three‐phase contact line is unpinned, the droplet spreads on the micropore surface. With the reduce of the contact angle or the increase of the diameter of the pore, the pinning time of the droplet is shortened, and the droplets spread faster on the micropore surface. As the inlet pressure increases, the droplets grow faster at the orifice and spread from the orifice until the apparent contact angle reaches its maximum forward angle. The spread promotes the regeneration of the lubricating film, which is conducive to improving the stability of the oil film on micropore surface. [ABSTRACT FROM AUTHOR]

Psoriasis is a chronic skin disease characterized by the hyperproliferation of keratinocytes and an overactive autoimmune response. Photodynamic therapy (PDT) has been established as a promising intervention for alleviating psoriasis. However, the current transdermal delivery of photosensitizers is inefficient and imprecise. In this study, we developed a foamed microemulsion nanodroplets system containing chlorin e6 (Ce6 FM), exhibiting precise epidermal targeting and retention, which targeted the aberrantly proliferating epidermal cells at psoriatic skin lesions and avoided the damage to the normal cutaneous cells. Upon application in a psoriatic mouse model, Ce6 FM efficiently induced keratinocyte apoptosis by generating reactive oxygen species under laser. Furthermore, Ce6 FM-based PDT activated the cyclooxygenase-2-induced immunosuppressive pathway in keratinocytes, resulting in the amelioration of the autoimmune microenvironment in psoriatic skin. Additionally, Ce6 FM-based PDT did not induce skin damage or atrophy associated with non-targeted halometasone treatment. Overall, Ce6 FM-based PDT holds promise as an effective, safe and compliant strategy for psoriasis treatment. [ABSTRACT FROM AUTHOR]

Lipid droplets (LDs) are evolutionarily conserved dynamic organelles that play an important role in cellular physiology. Growing evidence suggests that LD biogenesis occurs at discrete endoplasmic reticulum (ER) subdomains demarcated by the lipodystrophy protein, Seipin, lack of which impairs adipogenesis. However, the mechanisms of how these domains are selected is not completely known. These ER sites undergo ordered assembly of proteins and lipids to initiate LD biogenesis and facilitate establishment of ER-LD contact sites, a prerequisite for proper growth and maturation of droplets. LDs retain both physical and functional association with the ER throughout their lifecycle to facilitate bi-directional communication, such as exchange of proteins and lipids between the two organelles at these ER-LD contact sites. In recent years several molecular tethers have been identified that bridge ER and LDs together including few proteins that are found exclusively at these ER-LD contact interface. Here, we discuss recent advances in understanding the role of factors that ensure functionality of ER-LD contact site machinery for LD homeostasis. [ABSTRACT FROM AUTHOR]

Upon abiotic stress or senescence, the size and/or abundance of plastid-localized plastoglobules and cytosolic lipid droplets, both compartments devoted to neutral lipid storage, increase in leaves. Meanwhile, plant lipid metabolism is also perturbed, notably with the degradation of thylakoidal monogalactosyldiacylglycerol (MGDG) and the accumulation of neutral lipids. Although these mechanisms are probably linked, they have never been jointly studied, and the respective roles of plastoglobules and lipid droplets in the plant response to stress are totally unknown. To address this question, we determined and compared the glycerolipid composition of both lipid droplets and plastoglobules, followed their formation in response to nitrogen starvation, and studied the kinetics of lipid metabolism in Arabidopsis leaves. Our results demonstrated that plastoglobules preferentially store phytyl-esters, while triacylglycerols (TAGs) and steryl-esters accumulated within lipid droplets. Thanks to a pulse–chase labeling approach and lipid analyses of the fatty acid desaturase 2 (fad2) mutant, we showed that MGDG-derived C18:3 fatty acids were exported to lipid droplets, while MGDG-derived C16:3 fatty acids were stored within plastoglobules. The export of lipids from plastids to lipid droplets was probably facilitated by the physical contact occurring between both organelles, as demonstrated by our electron tomography study. The accumulation of lipid droplets and neutral lipids was transient, suggesting that stress-induced TAGs were remobilized during the plant recovery phase by a mechanism that remains to be explored. [ABSTRACT FROM AUTHOR]

Fog and low stratus clouds (FLS) form as a result of complex interactions of multiple factors in the atmosphere and at the land surface and impact both the anthropogenic and natural environments. Here, we analyze the role of synoptic conditions and aerosol loading on FLS occurrence and persistence in the Po valley in northern Italy. By applying k‐means clustering to reanalysis data, we find that FLS formation in the Po valley is either based on radiative processes or moisture advection from the Mediterranean sea. Satellite‐based data on FLS persistence shows longer persistence of radiatively formed FLS events, likely due to air mass stagnation and a temperature inversion. Ground‐based aerosol optical depth observations further reveal that FLS event duration is significantly higher under high aerosol loading. The results underline the combined effect of topography, moisture advection and aerosol loading on the FLS life cycle in the Po valley. Plain Language Summary: Fog and low stratus clouds (FLS) are influenced by various drivers in the atmosphere and near the ground. Here, the impact of the large‐scale weather situation and aerosols is analyzed over the Po valley in northern Italy. Using reanalysis and satellite data we find that FLS events driven by nighttime cooling under stable conditions can persist longer than FLS events formed as a result of moisture transport. Investigating ground‐based observations of aerosols, particles on which moisture can condensate and fog and cloud droplets form, we find that FLS event duration is higher when a higher amount of aerosols is present. These results can help when predicting the duration of FLS events, which is particularly important for traffic safety. Key Points: Fog and low stratus (FLS) cloud formation in the Po valley is primarily controlled by radiative processes or moisture advectionFLS persistence from the satellite perspective is highest for radiatively formed FLS events likely due to a stable boundary layerFLS persistence is significantly higher under high aerosol loading [ABSTRACT FROM AUTHOR]

Metabolic competition is a zero‐sum game between bacterial biofilms and host immune responses on the surface of medical implants. In an in vitro biofilm‐macrophages co‐culture system, it is found that suppressed lipid metabolic processes in host macrophages in the biofilm microenvironment correlates with immune tolerance and intracellular persistence. Reactivation of immune cells against bacterial infection by reprogramming lipid metabolism through the supply of lipids such as oleic acid (OA) is a promising strategy, but this cannot completely destroy the bacterial biofilms. Nanomaterial‐based zinc ion interference therapy in antibacterial field emerges relying on the outstanding benefits of nanomaterials. Therefore, a targeted nano‐fat HSA‐IR820@OA@ZIF‐8 (HIROZ) with near infrared‐II (NIR‐II) photothermal capacities is developed for the destrcution of the biofilms via zinc ion combined photothermal therapy. The improved cellular compatibility and enhanced intracellular uptake make HIROZ induce intracellular lipid droplets (LDs) formation in macrophages. Photothermal combined zinc ion‐induced metabolic interference augments the antimicrobial effect of LDs and activates lipometabolic reprogramming‐mediated antibacterial immune responses via mitochondrial stress. In the mouse wound biofilm infections model and subcutaneous implant‐associated biofilm infections (IABIs) model, HIROZ demonstrates sustained and thorough biofilm scavenging based on reprogramming of lipid metabolism, providing a new idea for metabolic interference‐centered therapeutic strategies for full‐scale IABIs eliminations. [ABSTRACT FROM AUTHOR]

SUMMARY Lipid droplets (LDs) are unusual organelles that have a phospholipid monolayer surface and a hydrophobic matrix. In oilseeds, this matrix is nearly always composed of triacylglycerols (TGs) for efficient storage of carbon and energy. Various proteins play a role in their assembly, stability and turnover, and even though the major structural oleosin proteins in seed LDs have been known for decades, the factors influencing LD formation and dynamics are still being uncovered mostly in the “model oilseed” Arabidopsis. Here we identified several key LD biogenesis proteins in the seeds of pennycress, a potential biofuel crop, that were correlated previously with seed oil content and characterized here for their participation in LD formation in transient expression assays and stable transgenics. One pennycress protein, the lipid droplet associated protein‐interacting protein (LDIP), was able to functionally complement the Arabidopsis ldip mutant, emphasizing the close conservation of lipid storage among these two Brassicas. Moreover, loss‐of‐function ldip mutants in pennycress exhibited increased seed oil content without compromising plant growth, raising the possibility that LDIP or other LD biogenesis factors may be suitable targets for improving yields in oilseed crops more broadly. [ABSTRACT FROM AUTHOR]

Investigating the self‐sorting behaviour of assemblies with subtle structural differences is a captivating yet challenging endeavour. Herein, we elucidate the unusual self‐sorting behaviour of metallacages with subtle structural differences in batch reactors and microdroplets. Narcissistic self‐sorting of metallacages has been observed for two ligands with identical sizes, shapes, and symmetries, with only minor differences in the substituted groups. In particular, the self‐sorting process in microdroplets occurs within 1 min at room temperature, in stark contrast to batch reactors, which require equilibration for 30 min. To reveal the mechanism of self‐sorting and the role of microdroplets, we conducted a series of experiments and theoretical calculations, including competitive self‐assembly, cage‐to‐cage transformation, control experiments involving model metallacages with larger cavities, noncovalent interaction analysis, and root mean square deviation (RMSD) analysis. This research demonstrates an unusual case of self‐sorting of very similar assemblies and provides a new strategy for facilitating the self‐sorting efficiency of supramolecular systems. [ABSTRACT FROM AUTHOR]

Communication between subcellular organelles is crucial for a synchronized cellular response which drives the search for chemical tools to simultaneously visualize dual organelles to unveil these dynamic interactions. A polarity‐sensitive dual organelle targeting dioxaborine derivative, namely DOBEL, which stains lipid droplets (LDs) and endoplasmic reticulum (ER) simultaneously is introduced. This report is the first to demonstrate how the intrinsic difference in micropolarity drives the visualization of LDs in the green channel while ER in the red channel involves a single probe. The in situ emission spectra inside these organelles allow polarity quantification, further leading to deciphering the unique microenvironments in different cell lines. Exploiting ratiometric fluorescence imaging revealed how the micropolarity inside both LDs and ER alters during Ferroptosis. Altogether, DOBEL can be used as a superior imaging tool for monitoring LD‐ER interaction during regular status and ferroptosis‐related diseases in living cells. [ABSTRACT FROM AUTHOR]

Droplet microarrays (DMAs) leveraging wettability differences are instrumental in digital immunoassays, single-cell analysis, and high-throughput screening. This study introduces an enhanced Teflon lift-off process to fabricate hydrophilic–hydrophobic patterns on a digital microfluidic (DMF) chip, thereby integrating DMAs with DMF technology. By employing DMF for droplet manipulation and utilizing wettability differences, the automated generation of high-throughput DMAs was achieved. The volume of the microdroplets ranged from picoliters to nanoliters. For droplets with a diameter of 150 μm, the array density reached up to 1282 cm−2. We systematically investigated the influence of various DMF parameters on the formation of DMAs and applied this technique to particle distribution, achieving a single-cell isolation rate of approximately 30%. We believe that this method will be a potent tool to enhance the capabilities of DMAs and DMF technology and extend their applicability across more fields. [ABSTRACT FROM AUTHOR]

Lipid droplets (LDs) are subcellular organelles that are dynamic and play a central role in energy homeostasis and lipid metabolism. They also contribute to the transport and maturation of cellular proteins and are closely associated with several diseases. The important role of the cellular microenvironment in maintaining cellular homeostasis. Changes in cell polarity, particularly in organelles, have been found to be strongly linked to inflammation, Alzheimer's disease, cancer, and other illnesses. It is essential to check the polarity of the LDs. A series of arylated naphthalimide derivatives were synthesized using the Suzuki reaction. Modification of synthesized aryl naphthalimides using oligomeric PEG based on intramolecular charge transfer (ICT) mechanism. A series of fluorescent probes were designed to target LDs and detect their polarity. Nap‐TPA‐PEG3 probe exhibited high sensitivity to polarity. The addition of oligomeric polyethylene glycol (PEG) to the probe not only significantly improved its solubility in water, but also effectively reduced its cytotoxicity. In addition, the probe exhibited excellent aggregation‐induced luminescence (AIE) properties and solvent discolouration effects. Nap‐TPA‐PEG3 probe exhibited high Pearson correlation coefficient (0.957163) in lipid droplet co‐localization in cells. Nap‐TPA‐PEG3 could be used as an effective hand tool to monitor cell polarity. [ABSTRACT FROM AUTHOR]

The droplet evaporation in sprays and clouds is largely influenced by the interacting surrounding droplets. This study presents a numerical investigation on the evaporation dynamics of two inline interacting droplets in a high-temperature vapor domain using ANSYS Fluent. Several methods are available to solve the multiphase flow problems with phase change, including level set, phase field, volume of fluid (VOF), and hybrid techniques. In the present study, the multiphase model equations are solved in the framework of the VOF method, which is a well-established and robust solver for multiphase flows with excellent volume conservation properties. The Lee model is used to handle the evaporative phase change at the interface. The droplet spacing, sizes, and arrangement pattern of differently sized droplets are the key parameters varied to explore their effects on the evaporation rate, droplet velocities, and inter-droplet distance. For equal-sized droplets, the evaporation of the trailing droplet slows down due to the low-temperature buffer layer of the droplet vapors generated by the evaporation of the leading droplet; the effects decrease as the initial spacing is increased. For two droplets at center-to-center distances of 2do and 6do, the evaporation of the trailing droplets reduces by 20.8% and 7%, respectively. Decreasing the size of the trailing droplet increases its evaporation rate since the smaller droplet experiences more temperature gradients as it escapes out of the influence of the leading drop buffer layer. For a smaller to larger droplet diameter ratio of 0.9, the evaporation rate of the trailing droplet is reduced by ~26% than expected. However, for the diameter ratio of 0.5, this reduction is only 12.5%. Regarding the arrangement pattern of different-sized droplets, the overall evaporation rate is lower when the bigger droplet follows the smaller one. The fact is attributed to close interaction followed by the coalescence of the bigger droplet with the leading smaller droplet, resulting in a single bigger droplet. [ABSTRACT FROM AUTHOR]

Nanodroplets have demonstrated potential for the range detection of hadron radiotherapies. Our formulation uses superheated perfluorobutane (C4F10) stabilized by a poly(vinyl-alcohol) shell. High-LET (linear energy transfer) particles vaporize the nanodroplets into echogenic microbubbles. Tailored ultrasound imaging translates the generated echo-contrast into a dose distribution map, enabling beam range retrieval. This work evaluates the response of size-sorted nanodroplets to carbon-ion radiation. We studied how thesize of nanodroplets affects their sensitivity at various beam-doses and energies, as a function of concentration and shell cross-linking. First, we show the physicochemical characterization of size-isolated nanodroplets by differential centrifugation. Then, we report on the irradiations of the nanodroplet samples in tissue-mimicking phantoms. We compared the response of large (≈900 nm) and small (≈400 nm) nanodroplets to different carbon-ions energies and evaluated their dose linearity and concentration detection thresholds by ultrasound imaging. Additionally, we verified the beam range detection accuracy for the nanodroplets samples. All nanodroplets exhibited sensitivity to carbon-ions with high range verification precision. However, smaller nanodroplets required a higher concentration sensitivity threshold. The vaporization yield depends on the carbon-ions energy and dose, which are both related to particle count/spot. These findings confirm the potential of nanodroplets for range detection, with performance depending on nanodroplets' properties and beam parameters. [ABSTRACT FROM AUTHOR]

A straightforward nebulized spray system is designed to explore the hydrogenation of carbon dioxide (CO2) within water microdroplets surrounded by different gases such as carbon dioxide, nitrogen, oxygen, and compressed air. The collected droplets are analyzed using water‐suppressed nuclear magnetic resonance (NMR). Formate anion (HCOO−), acetate anion (CH3COO−), ethylene glycol (HOCH2CH2OH), and methane (CH4) are detected when water is nebulized. This pattern persisted when the water is saturated with CO2, indicating that CO2 in the nebulizing gas triggers the formation of these small organics. In a pure CO2 atmosphere, the formate anion concentration is determined to be ≈70 µm, referenced to dimethyl sulfoxide, which has been introduced as an internal standard in the collected water droplets. This study highlights the power of water microdroplets to initiate unexpected chemistry for the transformation of CO2 to small organic compounds. [ABSTRACT FROM AUTHOR]

The generation of patterns by breaking the spatial symmetry in external confinement is a captivating area of physics. The emergence of patterns is a fundamental inquiry spanning various disciplines such as nonlinear optics, condensed matter physics, and fluid dynamics. The article investigates the generation of a variety of patterns in a one-dimensional binary mixture of Bose–Einstein condensate forming quantum droplets. By solving the extended Gross–Pitaevskii equation in the presence of tilted and driven engineered bi-chromatic optical lattices (BOL), the out-of-equilibrium dynamics of droplets under strong dc and ac fields are illustrated. Under the influence of a dc field, a stripe-like pattern emerges in the temporal domain, while the scenario with ac fields demonstrates temporal periodic and bi-periodic oscillations of density waves. The width and period of formed patterns are directly correlated with the strength of ac and dc fields. Moreover, temporal modulation of the BOL potential depth yields various harmonics in the oscillations of the condensate density pattern. Through Fast Fourier Transform (FFT) analysis, it is confirmed that these harmonics encompass multiple and combinational frequencies, suggesting potential applications in generating desired frequency combs within quantum droplets. We have also carried out a thorough numerical stability check of the obtained solutions and found them sufficiently stable. [ABSTRACT FROM AUTHOR]

Multi‐level anticounterfeiting tags have been developed using a combination of different materials. Polyvinyl alcohol (PVA) mixed with titanium dioxide (TiO2) is used to produce flexible substrates. Fluorescent Opuntia Ficus‐indica (OFI) extract dissolved with polymethyl methacrylate (PMMA) is then sprayed over the substrate to create a random, yet unique deposition of droplets. Photographs of the tags are taken under UV illumination at different angles and analyzed through the scale‐invariant feature transform (SIFT) algorithm to extract their unique features. The SIFT analysis reveals hundreds to thousands of matched features when a given tag is compared with itself, whereas this number drops to tens for different tags. To enhance the security of the tags, ITO is sputtered onto one of them in the form of a pattern formed by a patch array exhibiting a specific fingerprint at terahertz (THz) frequencies. The evaluation of ITO reflectance shows that each patch array has a unique and unpredictable response stemming from its distinct electro‐optical characteristics. The non‐deterministic response of sprayed dye droplets and ITO patches enables the realization of two‐level authentication, which is difficult to replicate at a reasonable cost. The simple manufacturing process and inexpensive materials involved make the proposed tags easily integrable into packaging. [ABSTRACT FROM AUTHOR]

The influence of entrainment, a key process characterized by the entrainment rate in cumulus parameterization, on aerosol‐cloud interactions has been widely recognized. However, despite qualitative links established between entrainment and aerosol loading, a quantitative relationship based on observational evidence remains elusive. This study utilizes aircraft observations of cumulus clouds during two field campaigns to determine the quantitative relationship between entrainment rate and aerosol loading. In both campaigns, the entrainment rate is negatively correlated with aerosol loading. It is speculated that increased aerosol loading enhances cloud edge droplet evaporation, which leads to increased buoyancy and vertical velocity within the cloud, thereby reducing the entrainment rate. Further analysis shows that the response of entrainment rate to aerosol perturbations is more significant in smaller cumulus clouds with weak buoyancy and less pronounced under opposite conditions. These findings shed new light on improving the description of aerosol‐cloud interactions in cumulus parameterizations. Plain Language Summary: Clouds play a crucial role in regulating Earth's climate, and understanding how they form and evolve is important for accurate weather and climate predictions. One key process affecting cloud development is entrainment, where drier air from outside the cloud mixes into the cloud, influencing its growth. Scientists know that aerosols can impact entrainment, but the exact relationship hasn't been clear. This study uses observations from research aircraft flown through cumulus clouds to quantify the relationship between entrainment and aerosol. The results show that aerosol concentration is negatively correlated with entrainment rate, meaning less dry air mixes into the cloud. We speculate that this happens because the increased aerosols enhance the evaporation of cloud droplets at the cloud edges, making the cloud more buoyant and less likely to mix with the surrounding air. Interestingly, this decline in entrainment rate to aerosol is stronger in smaller and weaker clouds. These findings provide valuable insights into how aerosols influence cloud development and can help improve the representation of aerosol‐cloud interactions in climate models, leading to more accurate climate projections. Key Points: The relationship between cumulus entrainment rate and aerosol loading is quantified based on observation for the first timeThe plausible physical mechanism linking entrainment rate to aerosol loading has been elucidatedA steeper decline in entrainment rate with increasing aerosol loading is observed in small and weakly buoyant cumulus clouds [ABSTRACT FROM AUTHOR]

Cloud phase has important impacts on Arctic surface temperatures, and circumstantial evidence suggests that dust aerosols have strong regional impacts on Arctic cloud phase. We used 7 years of satellite observations and model and reanalysis products to control for co‐varying meteorology, and to assess how dust and other aerosols impact cloud phase and cloud radiative effects over the summertime sea ice. We focus on clouds at 3 km, where dust modeling is most accurate. There is strong indication that dust aerosols caused about 4.5% of clouds below −15°C to change phase, with smaller effects at higher temperatures. Sulfate has a smaller impact on cloud phase. Dust is associated with cloud‐mediated surface cooling of up to a 6.3 W m−2 below single‐layer clouds at ∼3 km in June. This is the first observational study to constrain likely dust‐related cloud radiative effects over the summertime Arctic sea ice. Plain Language Summary: The amount of liquid and ice in clouds affects how much they warm or cool the surface in the rapidly warming Arctic. Dust aerosols cause cloud droplets to freeze and may be why clouds at similar temperatures are substantially icier over the Arctic than over the cleaner Antarctic. We used satellites and model information to better understand how clouds containing some dust were different from other clouds in similar meteorological conditions over summertime sea ice. At 3 km, where dust modeling is most reliable, about 4.5% more clouds below −15°C either contain some ice particles mixed with liquid droplets, or become fully composed of ice particles when dust is present. This occurs less often at warmer temperatures. Sulfate aerosol also seems to have an effect, though smaller, on the amount of liquid and ice in Arctic summertime clouds. Dustier clouds also cool the surface more than clouds with lower dust amounts. Key Points: Dust causes a fraction of Arctic clouds to change phase, leading to summertime cooling over sea iceThis is the first observational study to constrain likely dust‐related cloud radiative effects in this regionChanges to the cloud radiative effect (1.5 to 6.3 W m−2) may be underestimated here due to uncertainties in near‐surface dust concentrations [ABSTRACT FROM AUTHOR]