Relative Size Distribution Research Articles

Detection of a biological aerosol using optical particle counters

So far, detection and quantification of bio-aerosols requires genotypic or phenotypic identification of every single particle. Successful use of optical particle counters, as a time- and cost-saving alternative, has not been reported to date, indicating the need for further method development. Previously, such studies have focused on pollen. Here we report on a laboratory test of commercially available low-cost optical particle counters from Alphasense (OPC-N3 and OPC-R2) for the quantification of a known fungal aerosol (Botrytis cinerea). Aerosols were quantified using a Grimm Portable Aerosol Spectrometer (11E). Our measurements reveal that the low-cost sensors almost correctly detect the relative particle size distribution of the spores, as compared with the Grimm reference instrument, and potentially can be used in environmental detection of fungal aerosols.

Relative size distribution of business firms—A QRSE approach

Several studies have examined specific characteristics of firms while attempting to explain highly skewed firm size distribution and the presence of extreme values. This study adapted the quantal response statistical equilibrium model of boundedly rational firms and used firms’ probabilistic decision-making to infer the equilibrium relative size distribution. The theoretical model complements conventional and entropy-based concentration measures. The study presents an adaptation for business firms in the United States while investigating firms’ expansion decisions, aspired sizes, and responsiveness to opportunities.

Compact Symmetric Objects. II. Confirmation of a Distinct Population of High-luminosity Jetted Active Galaxies

Compact symmetric objects (CSOs) are compact (<1 kpc), jetted active galactic nuclei (AGN), whose jet axes are not aligned close to the line of sight, and whose observed emission is not predominantly relativistically boosted toward us. Two classes of CSOs have previously been identified: approximately one-fifth are edge dimmed and the rest are edge brightened. We designate these as CSO 1s and 2s, respectively. This paper focuses almost exclusively on CSO 2s. Using complete samples of CSO 2s we present three independent lines of evidence, based on their relative numbers, redshift distributions, and size distributions, which show conclusively that the vast majority (>99%) of CSO 2s do not evolve into larger-scale radio sources. These CSO 2s belong to a distinct population of jetted AGN, which should be characterized as “short-lived,” as opposed to “young,” compared to the classes of larger jetted AGN. We show that there is a sharp upper cutoff in the CSO 2 size distribution at ≈500 pc. The distinct differences between most CSO 2s and other jetted AGN provides a crucial new time domain window on the formation and evolution of relativistic jets in AGN and the supermassive black holes that drive them.

Proton Radiation Effect on Iron Thermal Oxides: Point Defects, Microstructure & Corrosion Electrochemistry

Iron(Fe)-based alloys, such as austenitic stainless steels, form protective surface oxide layers when exposed to oxygen, aqueous electrolyte, and water vapor, which effectively inhibit corrosion [1]. One attribute that underpins the electrochemical reactivity of surface oxide layers is the presence and properties of charged point defects (e.g. vacancies and interstitials charge compensated by electrons or holes), which govern the rate and mechanism of ionic transport when exposed to an oxidizing environment such as an aqueous electrolyte [2,3,4]. However, the effect of radiation on the relationship between point defects, oxide microstructure, and oxidation behavior is poorly understood. Structural materials used in nuclear applications are particularly susceptible to radiation damage, which can degrade the underlying surface oxides. To investigate this phenomenon, thermally oxidized pure Fe was selected as a model material system to study radiation-induced defects in iron oxide scales [3]. Iron oxides were fabricated by thermal oxidation of pure Fe metal in air at 400°C, 600oC, and 800°C for 1 hour. Each oxides layer exhibits an outer hematite (α-Fe2O3) and inner magnetite (Fe3O4)/wüstite (FeO) layers with varying thickness depending on the oxidation conditions. These oxides were then irradiated with 200 keV, 0.03 dpa protons at room temperature. The oxide microstructure and phase compositions were characterized with transmission electron microscopy (TEM) coupled with electron energy loss spectroscopy (EELS). These results were corroborated with X-Ray diffraction (XRD) and Raman spectroscopy analysis. The relative vacancy concentrations and size distributions in the oxide layers were investigated using positron annihilation spectroscopy (PAS) and positron annihilation lifetime spectroscopy (PALS) techniques. Lastly, these oxides were exposed to a 0.1 M borate buffer solution (pH 9.2) at applied potential where corrosion reactivity was governed by interfacial reactions and ionic defects to regulate the growth processes observed. The potentials were cycled over the ranges where oxides growth and reduction occurred involving Fe/Fe(II)/Fe(III) reactions at a pH which suppressed chemical reactions at the oxide/electrolyte interface and would lead to solubilization of Fe species. The subsequent oxidation, reduction, and semiconductor properties of the oxides were evaluated using AC and DC electrochemical methods, both with and without prior irradiation. Current results demonstrate that radiation damage can manifest itself in the form of vacancy clustering and possible maghemite (γ-Fe2O3) formation. These phenomena were corroborated with donor density and diffusivity values calculated using Mott-Schottky analysis and electrochemical impedance spectroscopy (EIS) analysis and equivalent circuit model (ECM) interpretation, respectively. Radiation damages to the outer rate-regulating α-Fe2O3 layer correlates with enhanced anodic current density corresponding to Fe/Fe(II)/Fe(III) reactions. However, proton radiation may also interact with the metal/oxide and oxide/oxide interfaces depending on the oxide structure and H+ beam penetration depth, leading to either degradation or improvement in the Fe-oxide corrosion responses. Nevertheless, the damage persists and can continue to impact corrosion mechanisms long after the irradiation source is removed. The multiple techniques adopted, each characterizing a material property of a different length scale (from meso-, micro-, to macroscopic) enable us to hypothesize the roles that point defects played after irradiation and during corrosion and how the radiation-induced changes in the defect characteristics influence corrosion electrochemistry. Acknowledgment Research primarily supported as part of the fundamental understanding of transport under reactor extremes (FUTURE), an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences. Utilization of the Malvern-Panalytical Empyrean diffractometer were supported by Nanoscale Materials Characterization Facility with National Science Foundation under award CHE-2102156. The TEM sample preparation and characterization was performed at the Analytical Instrumentation Facility at North Carolina State University, which is supported by the State of North Carolina and the National Science Foundation (award number ECCS-1542015). LANL is operated by Triad National Security, LLC, for the National Nuclear Security Administration of the U.S. DOE (Contract No. 89233218CNA000001).

Experimental study on the mechanical behavior and energy absorption capacity of coral sand at high strain rates

This study investigated and compared the compression responses and energy absorption capacities of coral sand and silica sand at a strain rate of approximately 1000 s−1. To this end, the effects of the relative density and particle size distribution on the abovementioned properties were analyzed, and the stress–strain curves, yield stresses, compressibilities, energy absorption curves, and energy absorption ratios were obtained. The experimental results showed that coral sand had a significantly higher energy absorption capacity than silica sand owing to its higher compressibility. The energy absorption curve for sand was primarily influenced by the yield stress and energy absorption ratio. The lower relative density of coral sand contributed to its higher compressibility and energy absorption capacity compared to silica sand. For coral and silica sands with different particle sizes, the intersection of the stress–strain and energy absorption curves was observed and analyzed. Formulas for predicting the yield stress, compressibility, and energy absorption curve of coral sand were derived, considering the variations in the relative density and particle size. The study findings reveal that using poorly graded coral sand with large particle sizes can improve the energy absorption capacity of coral sand.

Cisco population characteristics in Wisconsin lakes in relation to lake‐ and landscape‐level factors

AbstractObjectiveDeclines in Cisco Coregonus artedi populations in some inland lakes have prompted assessments of Cisco occurrence and extirpation risk in relation to various stressors to identify refuge lakes and factors that promote Cisco persistence. However, most previous assessments have focused on presence–absence of Cisco rather than examining how population characteristics, such as relative abundance or growth, might change in relation to lake‐ and landscape‐level environmental factors. Consequently, our specific objectives were to identify important environmental factors explaining variation in Cisco relative abundance and growth and to determine whether population metrics describing size and age distributions were related to relative abundance in Wisconsin inland lakes.MethodsCisco were collected from 48 inland Wisconsin lakes during 2011–2015 using vertical monofilament gill nets and population‐specific relative abundance estimates (catch per unit effort [CPUE]) were quantified as the number of individuals per gill‐net night. Sagittal otoliths were removed from a subsample of Cisco for age estimation and growth was indexed as mean total length (TL; mm) at age 2. Length and age data were used to develop a suite of metrics describing size and age distributions of each population. Random forest models were used to evaluate relationships between 10 biologically relevant predictor variables representing variation in physical, climatic, catchment, and limnological characteristics and Cisco CPUE and growth. Pearson correlations were used to determine whether population characteristics were related to CPUE.ResultCisco populations exhibited large variation in relative abundance, growth, and size and age distributions. Best‐fit random forest models explained approximately 25% of the variation in Cisco CPUE and 46% of the variation in growth. Growing degree‐days and variables associated with availability, quality, and quantity of suitable oxythermal conditions were identified as important predictors of both Cisco CPUE and growth; CPUE was also identified as an important predictor of growth. Mean TL and mean TL at age 2 were negatively related to Cisco CPUE, whereas mean age, number of age‐classes present, and maximum observed age were positively related to CPUE.ConclusionOur results suggest that maintenance of suitable oxythermal habitat conditions may be critical to conserving abundant Cisco populations. Our assessment also provides insights on how Cisco populations may respond to environmental and anthropogenic stressors, which could aid ongoing and future conservation and management efforts in Wisconsin and elsewhere.

On the process of fine sediment infiltration into static gravel bed: A CFD–DEM modelling perspective

AbstractThe gravel bed clogging, caused by infiltration and accumulation of fine sediment, degrades the river ecology. A proper understanding of the infiltration process, and underlying mechanism and causes, are necessary to take preventive measures. The process of fine sediment infiltration into static gravel bed is studied by distinguishing between bridging and percolation behaviours, as they affect the river ecology and physical processes occurring in the river system differently. However, several contradicting observations, concerning their occurrences, are reported. We employed the unresolved CFD–DEM method to simulate and investigate the infiltration process. The theoretical size ratios, corresponding to different geometrical configurations for a binary mixture of mono‐disperse spherical particles, representing bridging and percolation processes, are considered and simulated with and without flowing water effects. The effects of several turbulence models on the infiltration process are also studied. We found that fine sediment infiltration in fluvial deposits is mainly gravity‐dominated, supporting Cui's hypothesis that fine sediment infiltration through intra‐gravel flow is similar to fine sediment infiltration driven by gravity. In contrast to consensus in the field, our results demonstrate that the occurrences of different infiltration processes (bridging and percolation) seem to be independent of gravel bed thickness, rather depend only on the relative grain size distribution of fine sediment and gravel. However, a precise definition of a ‘thick enough’ gravel bed is necessary to distinguish between bridging and percolation behaviours. Here, we hypothesize a suitable gravel bed thickness, which might be regarded as a ‘thick enough’ gravel bed.

Effect of atomizer and cross-flows on liquid and gelled Jet A-1 fuel injection

The current study aims to experimentally investigate the effect of atomizer and cross-flow velocities on liquid and gelled Jet A-1 fuels. For gelled Jet A-1, Jet A-1 liquid, Thixatrol® ST and rectified xylene are the base fuel, gellant and solvent, respectively. Gelled Jet A-1 is prepared by adding 85% by weight of base fuel along with 7.5% by weight of gellant and solvent, each at optimum processing conditions. Atomization using a simple-plain-orifice atomizer is investigated to understand its effect on Jet A-1 gel fuel break-up without air cross-flow. Based on the investigation from qualitative flow visualization and quantitative analysis of Jet A-1 gel fuel break-up, a modified simple-plain-orifice atomizer called an internally impinging air-blast atomizer is made. Primary atomization using this new atomizer is studied to understand the break-up of liquid and gelled Jet A-1 gel fuels without any air cross-flow. Secondary atomization of liquid and gel fuel is investigated by transversely injecting fuel into different low-speed subsonic air cross-flow environments. Laser sheet Imaging (LSI) technique is used to capture spray images of both fuels. Break-up mechanisms of both liquid and gel fuels were observed, and the results were compared. Information on the cross-flow air mass flow rate effect on the liquid and gel spray is extracted by developing an algorithm in MATLAB using an image processing tool. Relative droplet size distribution of liquid and gel spray revealed their dependence on cross-flow air mass flow rate. Total droplet count of both liquid and gel fuel decreases significantly as the cross-flow Reynolds’ number increases. At higher cross-flow Reynolds’ number, gel droplets in the flow are observed to be more as compared to liquid fuel.

Multistep Extraction Transformation of Spent Coffee Grounds to the Cellulose-Based Enzyme Immobilization Carrier

The present study investigated the possibility of spent coffee ground (SCG) transformation to a cellulose-based enzyme immobilization carrier using a multistep extraction procedure. In the first step, SCGs were extracted with n-hexane by Soxhlet extraction in order to obtain SCG oil, while the remaining solid residue was subjected to continuous solvent flow sequential subcritical extraction with 96% and 50% ethanol and water. Afterwards, the obtained solid residue was subjected to alkaline liquefaction with 8% NaOH in order to remove lignin and produce cellulose-enriched SCGs as a potential enzyme immobilization carrier. Multistep extraction transformation of SCGs was monitored by chemical analysis of extracts and obtained solid residues. Soxhlet extraction of 100 g of SCGs yielded 10.58 g of SCG oil rich in linoleic and palmitic acid, while continuous solvent flow sequential subcritical extraction of 100 g of defatted SCGs yielded a total of 1.63 g of proteins, 5.58 g of sugars, 204 mg of caffeine, 76 mg of chlorogenic acid, and 11.97 mg of 5-(hydroxymethyl)furfural. Alkaline liquefaction of 100 g of sequentially extracted defatted SCGs by 8% NaOH yielded 7.45 g of proteins, 8.63 g of total polyphenols, 50.73 g of sugars, and 20.83 g of cellulose-enriched SCGs. Based on the characteristics of cellulose-enriched SCGs including a volume-weighted mean particle size of 277 μm, relative narrow particle size distribution with a span value of 1.484, water holding capacity of 7.55 mL/g, and a lack of carrier leakage, it could be safely concluded that produced cellulose-enriched SCGs fulfills criteria to be used as potential enzyme immobilization carrier. Overall, it seems that the proposed multistep extraction transformation of SCGs has great potential to be used for the production of several high-value added products.

Photo-Induced Cross-Linking of Unmodified α-Synuclein Oligomers.

Photo-induced cross-linking of unmodified proteins (PICUP) has been used in the past to study size distributions of protein assemblies. PICUP may, for example, overcome the significant experimental challenges related to the transient nature, heterogeneity, and low concentration of amyloid protein oligomers relative to monomeric and fibrillar species. In the current study, a reaction chamber was designed, produced, and used for PICUP reaction optimization in terms of reaction conditions and lighting time from ms to s. These efforts make the method more reproducible and accessible and enable the use of shorter reaction times compared to previous studies. We applied the optimized method to an α-synuclein aggregation time course to monitor the relative concentration and size distribution of oligomers over time. The data are compared to the time evolution of the fibril mass concentration, as monitored by thioflavin T fluorescence. At all time points, the smaller the oligomer, the higher its concentration observed after PICUP. Moreover, the total oligomer concentration is highest at short aggregation times, and the decline over time follows the disappearance of monomers. We can therefore conclude that these oligomers form from monomers.

Kinetic control of liposome size by direct lipid transfer

Spontaneous lipid vesiculation and related size distribution are traditionally studied in the framework of equilibrium thermodynamics and continuum mechanics, overlooking the kinetic aspects of the process. In the scenario of liposomes consisting of different lipid molecules dispersed in the same medium - a non-equilibrium situation -, the system evolves driven by lipid monomer transfer among the different liposomes. This process encompasses time-dependent changes in liposome size and size distribution, thus predicting size and composition at a given time would entail the control of the size of liposomes by kinetic means, an asset in the framework of diagnostics and synthetic biology. We introduce a direct transfer model, based on the fact that monomers are highly reactive species and apply it to saturated phospholipid molecules differing in hydrophobic chain length. Considering a well-defined gamma-type liposome size distribution, we demonstrate a clear liposome size-composition correlation and are able to predict liposome size and size distribution at any time in the transfer process. The size-composition correlation opens up new prospects for the control of the self-assembling properties of lipids and thereby the control of the liposome size.

Time–Space Evolution of the Groningen Gas Field in Terms ofb-Value: Insights and Implications for Seismic Hazard

AbstractThe Groningen gas field, located in the northeast of The Netherlands, is the Europe’s largest onshore gas field. It was discovered in 1959 and production started in 1963: Continuous production leads to reservoir compaction and subsidence, gradually loading preexisting fault and induced seismicity that started about 30 yr into the production. The seismic hazard and risk related to the induced seismicity is determined not only for the rate of activity, but it is also equally influenced by the relative size distribution of the seismicity—the b-value. I reanalyze the spatial and temporal evolution of the b-value in the field using an alternative approach to overcome magnitude in completeness heterogeneity, and link it to the evolution of fault loading and subsidence. Spatial variations of b-values are found to vary between 0.61 and 1.3, with the lowest observed values observed in the location of the 2012 M 3.6 Huizinge earthquake. In the last 10 yr, the mapped b-values are more homogeneous throughout the field. The spatial and temporal evolution of the b-value in the field in this study is shown to be quite complex, and systematically linked it to the evolution of fault loading, absolute compaction, and the rate of compaction—an important finding that offers new insights into hazard reduction and mitigation strategies of extraction relation-induced seismicity. Compaction rates below 2 mm/yr are not correlated to seismicity above M 2.0 in the history of the field, suggesting that low-volume production may be safer than that previously assumed.

On the impact of differential diffusion between soot and gas phase species in turbulent flames

The molecular diffusivities of larger PAHs and soot particles approach zero leading to differential diffusion with gas-phase species. The present work systematically quantifies the impact on soot moments, soot related statistical correlations and Particle Size Distributions (PSDs) using a fully coupled transported joint probability density function (JPDF) method featuring a 78-dimensional joint-scalar space, including enthalpy, gas phase species with the PSD discretised using 62 size classes via a mass and number density preserving sectional method. Differential diffusion of soot (DDS) is treated via a gradual decline of diffusivity among soot sections maintaining realisability and the expected exponential decay of variance. The solution of the flow field features a time-dependent second moment closure and an elliptic solver. The turbulent non-premixed Sandia C2H4 flame from the International Sooting Flame (ISF) data base was selected as a target along with the KAUST (C2H4/N2) variant of the same flame. Results show that reduced soot diffusion leads to a significant increase in the soot volume fraction RMS and that the correlation coefficient between soot volume fraction and temperature is further reduced in a particle-size-dependent manner. Similar observations are made for correlations between the soot volume fraction and the mass fractions of gas-phase species such as CO, OH, H and C2H2. The results suggest that computational methods that presume explicit (e.g. flame structure related) correlations between such scalars and with soot face leading order modeling challenges. It is also shown that the correlation between CO and soot increases due to oxidation of soot and that DDS leads to a modest downstream shift of PSDs towards larger particles.

Transient evolution of the relative size distribution of earthquakes as a risk indicator for induced seismicity

Induced earthquakes pose a substantial challenge to many geo-energy applications, and in particular to Enhanced Geothermal Systems. We demonstrate that the key factor controlling the seismic hazard is the relative size distribution of earthquakes, the b-value, because it is closely coupled to the stress conditions in the underground. By comparing high resolution observations from an Enhanced Geothermal System project in Basel with a loosely coupled hydro-mechanical-stochastic model, we establish a highly systematic behaviour of the b-value and resulting hazard through the injection cycle. This time evolution is controlled not only by the specific site conditions and the proximity of nearby faults but also by the injection strategy followed. Our results open up new approaches to assess and mitigate seismic hazard and risk through careful site selection and adequate injection strategy, coupled to real-time monitoring and modelling during reservoir stimulation.

Early detection of cancer using cell-free DNA (cfDNA) size analysis on a multiplexed amplicon-based next-generation sequencing (NGS) platform.

3041 Background: Tumor-derived cfDNA fragments are observed to be shorter in length than normal cfDNA. This size (length) difference can be analyzed as a tumor-specific signal. Whole genome or probe hybridization-based NGS methods can capture cfDNA fragments of native sizes. However, amplicon-based NGS assays are not directly amenable to cfDNA size analysis due to predetermination of amplicon sizes by design. Here we present a method to extract relative distribution of cfDNA fragment lengths from a targeted amplicon-based assay and show its utility in cancer detection. Methods: The LiquidHALLMARK cfDNA assay is an amplicon-based NGS test for the sensitive detection of genomic alterations in 80 genes. Although panel design is optimized for cfDNA with average amplicon length of ̃150 bp, the consecutive tiling design of amplicons for genes with contiguously targeted regions, e.g. BRCA permits the formation of longer amplicons (&gt; 150 bp) from physically subsequent primer pairs, provided longer template cfDNA molecules are present. Cancer samples (n = 281), clinically tested by LiquidHALLMARK during Sep 2020-Sep 2021, and healthy samples (n = 28) were included for analysis. For each sample, fragment lengths were inferred from sequencing alignment files, and binned into “short” (0-150 bp) and “long” (151-500 bp) groups. A relative “size ratio” of the total number of short vs. long fragments per sample was calculated, and examined with clinical features, plasma cfDNA concentration (cfDNA/ml) and highest mutation allele frequency (AF%), in a model to predict cancer. Results: Calculated size ratios (relative abundance of short fragments) were higher in cancer than normal samples (median 47.6 vs. 31.2, p &lt; 0.001). Cholangiocarcinoma and colorectal cancer samples had the highest size ratios (medians: 62.9 and 60.9, respectively) in agreement with a genome-wide NGS study that profiled cfDNA sizes. Size ratios were higher in metastatic (n = 143) compared to early stage (n = 30) lung cancers (p = 0.0039), indicating a stage-dependent accumulation of shorter cfDNA fragments. Size ratio was correlated with cfDNA/ml ( r= 0.63, p &lt; 0.01) and AF% ( r= 0.42, p &lt; 0.01). In 20-fold cross-validation of a logistic regression model trained to predict cancer, average area under curve (AUC) was 0.82 using size ratio, 0.86 using cfDNA/ml, and increased to 0.95 with the two features combined. Conclusions: Our analysis shows that it is feasible to derive meaningful cfDNA fragment size information from amplicon-based NGS data. Importantly, relative fragment size distributions observed in cancer and healthy plasma samples by this method are concordant with alternate target capture methods. Fragment size ratios derived from relatively small, targeted amplicon panels are a novel feature that, combined with other molecular and clinical features, can enhance non-invasive methods of cancer detection.

Experimental and numerical investigation of the effect of ultrasound on the growth kinetics of zeolite A

Ultrasound is a promising technology for the improvement of zeolite production, due to its beneficial effects on mass transfer and nucleation. However, a broad understanding of the sonication parameters that influence the growth of zeolites most is still lacking. In the present work, zeolite A was synthesized and the kinetic model of Gualtieri was used to obtain information about the crystallization parameters. The effect of the sonication power and duration on the relative crystallinity and particle size distribution were investigated using a Langevin-type transducer operating at 40 kHz. The experimental data shows that ultrasound has a significant effect on the nucleation and growth. With that, a reduction of up to 40 % of the initial synthesis time can be achieved. Additionally, a narrower particle size distribution is achieved when ultrasound is used during the zeolite A synthesis.

Microwave‐Assisted Synthesis of ZnO Nanoparticles: Phase Transfer to Water

Herein, a simple one‐pot procedure is reported to obtain aqueous zinc oxide (ZnO) nanoparticle dispersions from ZnO nanoparticles dispersed in cyclohexane. In the process, polyoxyethylene (20) sorbitan monooleate (polysorbate 80, Tween 80) functions as a phase transfer agent and colloidal stabilizer. The particles grow in a defined manner during the transfer, presumably via coalescence. The final particle radii are tuneable in the range from 2.3 ± 0.1 nm to 5.7 ± 0.1 nm depending on the incubation time of the dispersion at 90 °C. Small‐angle X‐ray scattering is employed to determine the particle radius distributions before and after phase transfer. The larger ZnO particle radii are associated with a redshift of the optical bandgap and luminescence emission, as expected for semiconductor nanoparticles. The particles presented here exhibit a relative size distribution width of 20%, rendering them attractive for applications in, e.g., biology or catalysis. The latter application is demonstrated at the photocatalytic degradation of methylene blue dye.

Capillary flow experiments for thermodynamic and kinetic characterization of protein liquid-liquid phase separation

Liquid-liquid phase separation or LLPS of proteins is a field of mounting importance and the value of quantitative kinetic and thermodynamic characterization of LLPS is increasingly recognized. We present a method, Capflex, which allows rapid and accurate quantification of key parameters for LLPS: Dilute phase concentration, relative droplet size distributions, and the kinetics of droplet formation and maturation into amyloid fibrils. The binding affinity between the polypeptide undergoing LLPS and LLPS-modulating compounds can also be determined. We apply Capflex to characterize the LLPS of Human DEAD-box helicase-4 and the coacervate system ssDNA/RP3. Furthermore, we study LLPS and the aberrant liquid-to-solid phase transition of α-synuclein. We quantitatively measure the decrease in dilute phase concentration as the LLPS of α-synuclein is followed by the formation of Thioflavin-T positive amyloid aggregates. The high information content, throughput and the versatility of Capflex makes it a valuable tool for characterizing biomolecular LLPS.

Analysis and Design of Lattice Structures for Rapid-Investment Casting.

This paper aims to design lattice structures for rapid-investment casting (RIC), and the goal of the design methodology is to minimize casting defects that are related to the lattice topology. RIC can take full advantage of the unprecedented design freedom provided by AM. Since design for RIC has multiple objectives, we limit our study to lattice structures that already have good printability, i.e., self-supported and open-celled, and improve their castability. To find the relationship between topological features and casting performance, various lattice topologies underwent mold flow simulation, finite element analysis, casting experiments, and grain structure analysis. From the results, the features established to affect casting performance in descending order of importance are relative strut size, joint number, joint valence, and strut angle distribution. The features deemed to have the most significant effect on tensile and shear mechanical performance are strut angle distribution, joint number, and joint valence. The practical application of these findings is the ability to optimize the lattice topology with the end goal of manufacturing complex lattice structures using RIC. These lattice structures can be used to create lightweight components with optimized functionality for various applications such as aerospace and medical.

Combined hyperosmolarity and inflammatory conditions in stressed human corneal epithelial cells and macrophages to evaluate osmoprotective agents as potential DED treatments

PurposeTo develop an easy-to-perform combined model in human corneal epithelial cells (HCECs) and Balb/c mice macrophages J774.A1 (MP) for preliminary screening of potential ophthalmic therapeutic substances. MethodsHCECs were exposed to different osmolarities (350–500 mOsm/L) and MTT assay was employed for cell survival and flow cytometry to assess apoptosis-necrosis and relative cell size (RCS) distribution. Effectiveness of Betaine, L-Carnitine, Taurine at different concentrations (ranging from 20 mM to 200 mM) was studied. Also, mucoadhesive polymers such as Hyaluronic acid (HA) and Hydroxypropylmethylcellulose (HPMC) (0.4 and 0.8%) were evaluated. Cells were pre-incubated with the compounds (8h) and then exposed to hyperosmotic stress (470 mOsm/L) for 16h. Moreover, anti-inflammatory activity was performed in LPS-stimulated MP. ResultsExposure to hyperosmotic solutions between 450 and 500 mOsm/L promoted the highest cell death after 16h exposures (p < 0.0001) with a drop in viability to 34.96% ± 11.77 for 470 mOsm/L. Pre-incubation with Betaine at 150 mM and 200 mM provided the highest cell survival against hyperosmolarity (66.01% ± 3.65 and 65.90% ± 0.78 respectively) while HA 0.4% was the most effective polymer in preventing cell death (42.2% ± 3.60). Flow cytometry showed that Betaine and Taurine at concentrations between 150-200 mM and 20–80 mM respectively presented the highest anti-apoptotic activity. Also, HA and HPMC polymers reduced apoptotic-induced cell death. All osmoprotectants modified RCS, and polymers increased their value over 100%. L-Carnitine 50 mM, Taurine 40 mM and HA 0.4% presented the highest TNF-α inhibition activity (60%) albeit all of them showed anti-inflammatory inhibition percentages higher than 20% ConclusionsHCECs hyperosmolar model combined with inflammatory conditions in macrophages allows the screening of osmoprotectants by simulating chronic hyperosmolarity (16h) and inflammation (24h).