Bonded straight and helical flagellar filaments form ultra-low-density glasses.

We study how the three-dimensional shape of rigid filaments determines the microscopic dynamics and macroscopic rheology of entangled semidilute Brownian suspensions. To control the filament shape we use bacterial flagella, which are microns-long helical or straight filaments assembled from flagellin monomers. We compare the dynamics of straight rods, helical filaments, and shape-diblock copolymers composed of seamlessly joined straight and helical segments. Caged by their neighbors, straight rods preferentially diffuse along their long axis, but exhibit significantly suppressed rotational diffusion. Entangled helical filaments escape their confining tube by corkscrewing through the dense obstacles created by other filaments. By comparison, the adjoining segments of the rod-helix shape-diblocks suppress both the translation and the corkscrewing dynamics. Consequently, the shape-diblock filaments become permanently jammed at exceedingly low densities. We also measure the rheological properties of semidilute suspensions and relate their mechanical properties to the microscopic dynamics of constituent filaments. In particular, rheology shows that an entangled suspension of shape rod-helix copolymers forms a low-density glass whose elastic modulus can be estimated by accounting for how shear deformations reduce the entropic degrees of freedom of constrained filaments. Our results demonstrate that the three-dimensional shape of rigid filaments can be used to design rheological properties of semidilute fibrous suspensions.

The onset of heterogeneity in the pinch-off of suspension drops.

SignificanceThe pinch-off of a liquid drop extruded from a nozzle is a canonical situation that involves a series of self-similar regimes ending in a finite-time singularity. This configuration allows for exploring capillary flows over a large range of scales. In the case of suspension drops, the presence of particles breaks the self-similarity by introducing a length scale that can be much larger than the particle diameter. This length scale is a signature of the heterogeneities and delimitates a regime, in which a continuum approach of a suspension can be used from a regime where the discrete nature of the particles is involved.

Quantifying the hydrodynamic contribution to electrical transport in non-Brownian suspensions.

Electrical transport in semiconducting and metallic particle suspensions is an enabling feature of emerging grid-scale battery technologies. Although the physics of the transport process plays a key role in these technologies, no universal framework has yet emerged. Here, we examine the important contribution of shear flow to the electrical transport of non-Brownian suspensions. We find that these suspensions exhibit a strong dependence of the transport rate on the particle volume fraction and applied shear rate, which enables the conductivity to be dynamically changed by over 107 decades based on the applied shear rate. We combine experiments and simulations to conclude that the transport process relies on a combination of charge and particle diffusion with a rate that can be predicted using a quantitative physical model that incorporates the self-diffusion of the particles.

Evaluation of the Effect of Polyethylenimine on Boron Adsorption by Soil Minerals.

The removal of hazardous ions from water is crucial for safeguarding both the environment and human health. Soil minerals, integral components of soil, play a vital role as adsorbents for various contaminants, including heavy metal ions, organic dyes, and detergents. This study investigates the interaction between boron ions and soil minerals (gibbsite, kaolinite, and montmorillonite) in the presence of polyethylenimine (PEI). The minerals underwent characterization based on specific surface area, particle size distribution, zeta potential, and the presence of functional groups. The influence of PEI addition on the stability of the soil mineral suspension was evaluated by turbidimetry. Mineral-boron and mineral-boron-PEI interactions were explored under varying conditions, including pH, initial boron concentration, and mineral quantity, with all adsorption experiments conducted over 24 hours. Using the Langmuir isotherm, the maximum adsorption capacity of the studied minerals was determined for boron both without and in the presence of PEI. For gibbsite, kaolinite and montmorillonite, it was 30.63, 24.55 and 26.62 mg g-1, respectively, while in the presence of PEI, it increased to 33.11, 26.61 and 45.47 mg g-1, respectively. The addition of PEI enhanced boron adsorption from aqueous solutions, increasing the removal efficiency from 65 % to about 80 %.

Extracellular vesicles derived from stored red blood cell suspensions enhance invasion and migration of lung cancer cells by miR1246 and miR150-3p.

BACKGROUND AND OBJECTIVES: Aged red blood cell (RBC) transfusions in lung cancer patients are often related to cancer recurrence and shorter lifespans. Extracellular vesicles (EVs) accumulated in stored RBC suspensions may be one of the important influential factors. This study aims to investigate how EVs derived from RBC suspensions affect the progress of lung cancer through the most enriched microRNAs (miRNAs) previously reported in our research. STUDY DESIGN AND METHODS: EVs derived from stored RBC suspensions in Weeks 1, 3 and 5 were harvested via ultracentrifugation. Lung adenocarcinoma H1975 cells were co-cultured with EVs and transfected with miR1246 and miR150-3p mimics to evaluate alterations in their proliferation, invasion and migration abilities in vitro. Proteomics and bioinformatics were performed to predict the signalling pathway related to invasion and migration of H1975, which were verified by western blotting (WB) and flow cytometry. RESULTS: EVs derived from stored RBC suspensions in Weeks 3 and 5 could significantly enhance the invasion and migration ability of H1975 cells and also increase the expression of miR1246 and miR150-3p. After transfection with miR1246 and miR150-3p mimics, invasion, migration and proliferation of H1975 cells were obviously enhanced. Proteomics analysis demonstrated that EVs co-cultivation and miRNA transfection groups were both enriched in cell adhesion molecules. WB and cytometry indicated that integrin beta-1 (ITGB1) and Rap1b were increased. CONCLUSIONS: EVs derived from stored RBC suspensions can enhance invasion and migration ability of lung cancer cells via the most accumulated miR1246 and miR150-3p, which may increase the expression of ITGB1 through Rap1 signalling pathway.

Paving the way for new and challenging matrix reference materials-particle suspensions at the core of material processing providing RMs for method development and method validation.

Sufficient homogeneity of the certified parameter(s) over the whole fill series of a matrix reference material (RM) is a fundamental quality criterion. In practice, the heterogeneity of the target parameter is evaluated, whereby a relative value can be calculated of how much the target parameter is varying over the RM-batch. A high degree of homogeneity (low heterogeneity) is an inherent quality mark of a good RM. Here, we report how challenging matrix RMs were produced by using particle suspensions at the core of the material processing step. The examples of matrix RMs produced span from whole water reference materials for persistent organic pollutants, PM2.5-like atmospheric dust certified for specific ions to microplastic RMs. Most of these RMs were subsequently used in different phases of analytical method development or for method validation. Common to all these matrices is that they cannot be easily mixed, handled, or dosed to prepare larger sample batches. In all cases, a continuously stirred suspension of particles was used during material processing. In general, relative between-bottle heterogeneities from 1.6 to 6% were achieved for the target parameters in these matrix presentations. Concerning developments of new CRMs in emerging fields, the co-dependence between the availability of validated analytical methods with good repeatability and testing materials with a known and high homogeneity of the target parameter(s) becomes particularly challenging. This situation is an RM/Method causality dilemma. To overcome that hurdle, strategies are proposed for stepwise processes where RM producers and a network of analytical method developers could work hand in hand. In addition, development of a portfolio of inexpensive and well-homogenised common samples coupled with a reporting interface is suggested. This would benefit method developers and RM producers alike. As more and more data is compiled for a specific matrix, it paves the way for new and challenging RMs that can later be used by a wider community.

The efficacy and safety of autologous epidermal cell suspensions for re-epithelialization of skin lesions: A systematic review and meta-analysis of randomized trials.

BACKGROUND: Successful usage of autologous skin cell suspension (ASCS) has been demonstrated in some clinical trials. However, its efficacy and safety have not been verified. This latest systematic review and meta-analysis aim to examine the effects of autologous epidermal cell suspensions in re-epithelialization of skin lesions. METHODS: Relevant articles were retrieved from PubMed, Embase, Cochrane Database, Web of Science, International Clinical Trials Registry Platform, China National Knowledge Infrastructureris, VIP Database for Chinese Technical Periodicals and Wanfang database. The primary output measure was the healing time, and the secondary outputs were effective rate, size of donor site for treatment, size of study treatment area, operation time, pain scores, repigmentation, complications, scar scale scores and satisfaction scores. Data were pooled and expressed as relative risk (RR), mean difference (MD) and standardized mean difference (SMD) with a 95% confidence interval (CI). RESULTS: Thirty-one studies were included in this systematic review and meta-analysis, with 914 patients who received autologous epidermal cell suspensions (treatment group) and 883 patients who received standard care or placebo (control group). The pooled data from all included studies demonstrated that the treatment group has significantly reduced healing time (SMD = -0.86; 95% CI: -1.59-0.14; p = 0.02, I2 = 95%), size of donar site for treatment (MD = -115.41; 95% CI: -128.74-102.09; p<0.001, I2 = 89%), operation time (MD = 25.35; 95% CI: 23.42-27.29; p<0.001, I2 = 100%), pain scores (SMD = -1.88; 95% CI: -2.86-0.90; p = 0.0002, I2 = 89%) and complications (RR = 0.59; 95% CI: 0.36-0.96; p = 0.03, I2 = 66%), as well as significantly increased effective rate (RR = 1.20; 95% CI: 1.01-1.42; p = 0.04, I2 = 77%). There were no significant differences in the size of study treatment area, repigmentation, scar scale scores and satisfaction scores between the two groups. CONCLUSION: Our meta-analysis showed that autologous epidermal cell suspensions is beneficial for re-epithelialization of skin lesions as they significantly reduce the healing time, size of donar site for treatment, operation time, pain scores and complications, as well as increased effective rate. However, this intervention has minimal impact on size of treatment area, repigmentation, scar scale scores and satisfaction scores.

Biodegradable Long-Acting Injectables: Platform Technology and Industrial Challenges.

Long-acting injectables have been used to benefit patients with chronic diseases. So far, several biodegradable long-acting platform technologies including drug-loaded polymeric microparticles, implants (preformed and in situ forming), oil-based solutions, and aqueous suspension have been established. In this chapter, we summarize all the marketed technology platforms and discuss their challenges regarding development including but not limited to controlling drug release, particle size, stability, sterilization, scale-up manufacturing, etc. Finally, we discuss important criteria to consider for the successful development of long-acting injectables.

Exact Results for Non-Newtonian Transport Properties in Sheared Granular Suspensions: Inelastic Maxwell Models and BGK-Type Kinetic Model.

The Boltzmann kinetic equation for dilute granular suspensions under simple (or uniform) shear flow (USF) is considered to determine the non-Newtonian transport properties of the system. In contrast to previous attempts based on a coarse-grained description, our suspension model accounts for the real collisions between grains and particles of the surrounding molecular gas. The latter is modeled as a bath (or thermostat) of elastic hard spheres at a given temperature. Two independent but complementary approaches are followed to reach exact expressions for the rheological properties. First, the Boltzmann equation for the so-called inelastic Maxwell models (IMM) is considered. The fact that the collision rate of IMM is independent of the relative velocity of the colliding spheres allows us to exactly compute the collisional moments of the Boltzmann operator without the knowledge of the distribution function. Thanks to this property, the transport properties of the sheared granular suspension can be exactly determined. As a second approach, a Bhatnagar-Gross-Krook (BGK)-type kinetic model adapted to granular suspensions is solved to compute the velocity moments and the velocity distribution function of the system. The theoretical results (which are given in terms of the coefficient of restitution, the reduced shear rate, the reduced background temperature, and the diameter and mass ratios) show, in general, a good agreement with the approximate analytical results derived for inelastic hard spheres (IHS) by means of Grad's moment method and with computer simulations performed in the Brownian limiting case (m/mg→∞, where mg and m are the masses of the particles of the molecular and granular gases, respectively). In addition, as expected, the IMM and BGK results show that the temperature and non-Newtonian viscosity exhibit an S shape in a plane of stress-strain rate (discontinuous shear thickening, DST). The DST effect becomes more pronounced as the mass ratio m/mg increases.

In Vitro and In Vivo Cysticidal Effects of Carica Papaya Cell Suspensions.

Parasitic diseases are a major public health problem worldwide. Plant-derived products appear to be ideal candidates from a biotechnological perspective, being sustainable and environmentally friendly. The antiparasitic properties of Carica papaya have been attributed to some of its components, including papain and other compounds that are concentrated in the latex and seeds. This study demonstrated in vitro a high and insignificantly different cysticidal activity of soluble extract that was obtained after the disruption of nontransformed wild-type (WT) cells as well as transformed papaya calluses (PC-9, PC-12, and PC-23) and papaya cell suspensions (CS-9, CS-12, and CS-23). In vivo, cell suspensions of CS-WT and CS-23 that had been previously lyophilized were tested with respect to their cysticidal effects, compared with those of three commercial antiparasitic drugs. CS-WT and CS-23 together reduced the number of cysticerci, the number of buds, and the percentage of calcified cysticerci in a similar extent to albendazole and niclosamide, whereas ivermectin was less effective. Mice were then orally immunized with CS-23 that expressed the anti-cysticercal KETc7 antigen (10 µg/mouse), CS-WT (10 mg/mouse), or both together to evaluate their preventive properties. CS-23 and CS-WT significantly reduced the expected parasite and increased the percentage of calcified cysticerci as well as recovery, being more effective when employed together. The results reported in this study support the feasibility of the development of an anti-cysticercosis vaccine from cells of C. papaya in in vitro cultures, as they are a source of an anthelmintic, natural, and reproducible product.

Silymarin mediated osmotic responses and damage in HepG2 cell suspensions and monolayers.

Maintenance of cells within a volume range compatible with their functional integrity is a critical determinant of cell survival after cryopreservation, and quantifying this osmotically induced damage is a part of the rational design of improved cryopreservation protocols. The degree that cells tolerate osmotic stress significantly impacts applicable cryoprotocols, but there has been little research on the time dependence of this osmotic stress. Additionally, the flavonoid silymarin has been shown to be hepatoprotective. Therefore, here we test the hypotheses that osmotic damage is time-dependent and that flavonoid inclusion reduces osmotic damage. In our first experiment, cells were exposed to a series of anisosmotic solutions of graded hypo- and hypertonicity for 10-40 min, resulting in a conclusion that osmotically induced damage is time dependent. In the next experiment, adherent cells preincubated with silymarin at the concentration of 10-4 mol/L and 10-5 mol/L showed a significant increase in cell proliferation and metabolic activity after osmotic stress compared to untreated matched controls. For instance, when adherent cells preincubated with 10-5 mol/L silymarin were tested, resistance to osmotic damage and a significant increase (15%) in membrane integrity was observed in hypo-osmotic media and a 22% increase in hyperosmotic conditions. Similarly, significant protection from osmotic damage was observed in suspended HepG2 cells in the presence of silymarin. Our study concludes that osmotic damage is time dependent, and the addition of silymarin leads to elevated resistance to osmotic stress and a potential increase in the cryosurvival of HepG2 cells.

The Impact of Restorative Practices on the Use of Out-of-School Suspensions: Results from a Cluster Randomized Controlled Trial.

The overuse of exclusionary discipline practices, such as out-of-school suspensions (OSS), has consistently been documented over several decades. The resulting racial discipline disparities and the negative outcomes related to OSS have led policy makers and educators to consider other approaches to school discipline. One such approach, which has gained increasing use in the USA, is restorative practices (RP). However, despite its popularity, the experimental evidence base of the effects of RP and suspensions is extremely limited. To add to this knowledge base, we present findings from a cluster randomized controlled trial with 18 K-12 schools in an urban district in the US Northeast with 5878 students. Multilevel regression results, after 1 year of the intervention, showed no differences in the likelihood of suspension between students in the intervention and control schools and that the effects of the intervention did not vary by race/ethnicity, gender, or student disability status. However, for students in the intervention group, we show reductions in the likelihood of receiving an OSS for students who had previously been suspended.

Controlled Production of Carnosic Acid and Carnosol in Cell Suspensions of Lepechinia meyenii Treated with Different Elicitors and Biosynthetic Precursors.

Lepechinia meyenii is a medicinal plant specialized in the biosynthesis of different types of antioxidants including the diterpenes carnosic (CA) acid and carnosol (CS). Herein we present the results of plant tissue culture approaches performed in this medicinal plant with particular emphasis on the generation and evaluation of a cell suspension system for CA and CS production. The effect of sucrose concentration, temperature, pH, and UV-light exposure was explored. In addition, diverse concentrations of microbial elicitors (salicylic acid, pyocyanin, Glucanex, and chitin), simulators of abiotic elicitors (polyethylene glycol and NaCl), and biosynthetic precursors (mevalonolactone, geranylgeraniol, and miltiradiene/abietatriene) were evaluated on batch cultures for 20 days. Miltiradiene/abietatriene obtainment was achieved through a metabolic engineering approach using a recombinant strain of Saccharomyces cerevisiae. Our results suggested that the maximum accumulation (Accmax ) of CA and CS was mainly conferred to stimuli associated with oxidative stress such as UV-light exposure (Accmax , 6.2 mg L-1 ) polyethylene glycol (Accmax , 6.5 mg L-1 ) NaCl (Accmax , 5.9 mg L-1 ) which simulated drought and saline stress, respectively. Nevertheless the bacterial elicitor pyocyanin was also effective to increase the production of both diterpenes (Accmax , 6.4 mg L-1 ). Outstandingly, the incorporation of upstream biosynthetic precursors such as geranylgeraniol and miltiradiene/abietatriene, generated the best results with Accmax of 8.6 and 16.7 mg L-1 , respectively. Optimized batch cultures containing 100 mg L-1 geranylgeraniol, 50 mg L-1 miltiradiene/abietatriene (95 : 5 %) and 5 g L-1 polyethylene glycol treated with 6 min UV light pulse during 30 days resulted in Accmax of 26.7 mg L-1 for CA and 17.3 mg L-1 for CS on days 18-24. This strategy allowed to increase seven folds the amounts of CA and CS in comparison with batch cultures without elicitation (Accmax , 4.3 mg L-1 ).

Dividend suspensions and cash flows during the Covid-19 pandemic: A dynamic econometric model.

Firms suspended dividend payments in unprecedented numbers in response to the outbreak of the Covid-19 pandemic. We develop a multivariate dynamic econometric model that allows dividend suspensions to affect the conditional mean, volatility, and jump probability of growth in daily industry-level dividends and demonstrate how the parameters of this model can be estimated using Bayesian Gibbs sampling methods. We find considerable heterogeneity across industries in the dynamics of daily dividend growth and the impact of dividend suspensions.

The Effect of Glycerol-Based Suspensions on the Characteristics of Resonators Excited by a Longitudinal Electric Field.

This study examines the effect of suspensions based on pure glycerol and diamond powder with different concentrations on the characteristics of resonators with a longitudinal electric field. We used two disk resonators made of the quartz and langasite plates with round electrodes on both sides of the plate and resonant frequencies of 4.4 and 4.1 MHz, operating in shear and longitudinal acoustic modes, respectively. Each resonator was mounted on the bottom of a 30 mL liquid container. During the experiments, the container was filled with the suspension under study in such a way that the resonator was completely immersed in the suspension, and the frequency dependences of the real and imaginary parts of the electrical impedance of the resonator were measured. As a result, the shear modulus of the elasticity and shear coefficient of the viscosity of the studied suspensions were determined. The material constants of the suspensions were found by fitting the theoretical frequency dependences of the real and imaginary parts of the electrical impedance of the resonator to the experimentally measured ones, which was calculated using Mason's equivalent circuit. As a result, the dependencies of the density, shear modulus of elasticity, shear viscosity coefficient, and velocity of the shear acoustic wave on the volume concentration of the diamond particles were constructed.

Concentration Scaling on Linear Viscoelastic Properties of Cellular Suspensions and Effects of Equilibrium Phase Behavior.

Concentration scaling on linear viscoelastic properties of cellular suspensions has been studied by rheometric characterisation of Phormidium suspensions and human blood in a wide range of volume fraction under small amplitude oscillatory shear experiments. The rheometric characterisation results are analysed by the time-concentration superposition (TCS) principle and show a power law scaling of characteristic relaxation time, plateau modulus and the zero-shear viscosity over the concentration ranges studied. The results show that the concentration effect of Phormidium suspensions on their elasticity is much stronger than that of human blood due to its strong cellular interactions and a high aspect ratio. For human blood, no obvious phase transition could be observed over the range of hematocrits studied here and with respect to a high-frequency dynamic regime, only one concentration scaling exponent could be identified. For Phormidium suspensions with respect to a low-frequency dynamic regime, three concentration scaling exponents in the volume fraction Region I (0.36≤ϕ/ϕref≤0.46), Region II (0.59≤ϕ/ϕref≤2.89) and Region III (3.11≤ϕ/ϕref≤3.44) are identified. The image observation shows that the network formation of Phormidium suspensions occurs as the volume fraction is increased from Region I to Region II; the sol-gel transition takes place from Region II to Region III. In combination with analysis of other nanoscale suspensions and liquid crystalline polymer solutions reported in the literature, it is revealed that such a power law concentration scaling exponent depends on colloidal or molecular interactions mediated with solvent and is sensitive to the equilibrium phase behaviour of complex fluids. The TCS principle is an unambiguous tool to give a quantitative estimation.

Long Acting Ionically Paired Pamoate-based Suspension of Lurasidone: An exploration of Size Effects on in vitro Dissolution and in vivo Pharmacokinetic Behaviors.

Latuda® is an oral tablet approved by the US Food and Drug Administration (FDA) for the treatment of schizophrenia. However, the clinical efficacy of Latuda® is compromised by patient noncompliance due to frequent daily administration, especially for patients experiencing severe schizophrenia, whose medication is often needed for several months to years. Hence, developing a long-acting injectable formulation of lurasidone is urgently needed. Herein, a poorly water-soluble lurasidone pamoate (LP) salt was synthesized via the facile ion pair-based salt formation technology. The solubility of LP was decreased by 233 folds compared with that of lurasidone hydrochloride (LH). Furthermore, suspensions of LH and LP with three different particle sizes, including 400 nm small-sized nanocrystals (SNCs), 4 µm medium-sized microcrystals (MMCs), and 15 µm large-sized microcrystals (LMCs) were prepared and characterized by powder X-ray diffraction (PXRD) and differential scanning calorimetry (DSC). The in vitro release results showed that particle sizes had great effects on the sustained release of LH, where large-sized particles exhibited superior sustained release than the smaller ones. Besides, LP suspensions exhibited better sustained release than LH suspensions at the same size scale. Moreover, the pharmacokinetics showed that LP LMCs produced an extended in vivo intramuscularly injectable profile for up to 45 days, which was 10 days longer than that of the LH LMCs. Our findings demonstrated that particle size had appreciable impacts on drug sustained release and provided valuable knowledge for the rational design of optimized micronized suspensions for long-acting injectables.

Payout suspensions during the Covid-19 pandemic.

We provide evidence on the unprecedented rate at which firms suspended dividend payments and share repurchases following the outbreak of the Covid-19 pandemic, compare it to the Global Financial Crisis, and estimate the amount of cash firms saved through payout suspensions.

Plant material selection, collection, preservation, and storage for nuclear DNA content estimation.

In theory, any plant tissue providing intact nuclei in sufficient quantity is suitable for nuclear DNA content estimation using flow cytometry (FCM). While this certainly opens a wide variety of possible applications of FCM, especially when compared to classical karyological techniques restricted to tissues with active cell division, tissue selection and quality may directly affect the precision (and sometimes even reliability) of FCM measurements. It is usually convenient to first consider the goals of the study to either aim for the highest possible accuracy of estimates (e.g., for inferring genome size, detecting homoploid intraspecific genome size variation, aneuploidy, among others), or to decide that histograms of reasonable resolution provide sufficient information (e.g., ploidy level screening within a single model species). Here, a set of best practices guidelines for selecting the optimal plant tissue for FCM analysis, sampling of material, and material preservation and storage are provided. In addition, factors potentially compromising the quality of FCM estimates of nuclear DNA content and data interpretation are discussed.

Suspension of Oncology Randomized Clinical Trials during the COVID-19 Pandemic: A Cross-Sectional Evaluation of COVID-Related Suspensions.

We conducted a cross-sectional analysis of ClinicalTrials.gov-registered oncology randomized controlled trials between September 2019 and December 2021 to identify predictors of trial suspensions. The dataset included 1,183 oncology trials, of which 384 (32.5%) were suspended. COVID-19 accounted for 47 (12.2%) suspensions. Trials that were single center- or US-based had higher odds of COVID-19 (ORs: 3.85 and 2.48, 95% CIs: 1.60-11.50 and 1.28-4.93, respectively) or any-reason suspensions (ORs: 2.33 and 2.04, 95% CIs: 1.46-3.45 and 1.40-2.76, respectively). Phase two (OR 1.27), three (OR 6.45) and four trials (OR 11.5) had increased odds of COVID-19 suspensions, compared to phase one trials.