Granule Matrix Research Articles

Caliche From Archaeological Zone of Guanajuato Mexico and Nearby Deposits: Geochemical and Mechanical Characterizations

ABSTRACT Currently, several archaeological sites are being studied in the Mexican state of Guanajuato. Among these sites is the Cerro de Los Remedios, located in the municipality of Comonfort, in the state of Guanajuato. The archaeological site shows that among the main materials used for construction was a carbonate-based stone called caliche. Caliche is the result of carbonate sedimentation in sandstone; therefore, its physical and geochemical characteristics are specific to each archaeological zone around the world. Therefore, it was necessary to conduct a study of the chemical, physical, and mechanical properties of the material found. Samples were removed from the CZA archaeological site and characterized by infrared spectroscopy, XRD, X-ray fluorescence and SEM. The results showed that more than 93% of the caliche is composed of CaCO3 as a matrix of micrite and calcite granules. In addition, the physical and mechanical properties were determined, including density, porosity, and uniaxial compression stress. With the results obtained from the samples from the archaeological site, it was possible to identify material banks close to the caliche properties that were most like those used at the site, which can be proposed to be used in the conservation work required at the archaeological site.

Insights into the rapid granulation for treating refractory wastewater under salt stress: Variation of sludge property, treatment performance and microbial community

Industrial effluents often contain high total dissolved solids, which exhibit negative effects on microorganisms. In this study, the granulation process under salt stress in the presence of aniline (a common organic pollutant in several types of industrial wastewaters) was evaluated. The sludge properties, removal performance of pollutants and microbial community structure were investigated. Two reactors, namely R1 and R2 were set up, and influent in R1 contained 15 g L−1 of NaCl while R2 was in the absence of salt as contrast. Results showed that aerobic granules appeared within 20 d under saline conditions with 30 min sludge volume index (SVI30) below 36 mL g−1. High salinity led to larger granule size and extracellular polymeric substances was 1.3 times higher than those in R2. However, part of Ca2+ ions in the bio-aggregate matrix of granules were replaced by Na+ ions in the saline environment, resulting in the modestly higher SVI30. Regarding the treatment performance, high removal efficiencies of aniline and COD were observed (~100% and 93.7%, respectively) after 4-h treatment under saline condition while both nitrification and denitrification were slightly retarded. The average concentration of NH4+-N and TN in the effluent of R1 after formation of granules were 1.2 ± 0.4 and 17.3 ± 1.7 mg L−1, respectively. Microbial community analysis indicated that saline condition could facilitate microorganisms with high flocculation activity and high tolerance to salinity such as Paraclostridium, Citrobacter, and Flavobacterium, which contributed to simultaneous removal of organics and nitrogen in AGS process for treating saline refractory wastewater.

Hydroxypropyl Methylcellulose as Hydrogel Matrix and Citric Acid-Locust Bean Gum as Negative Matrix for Controlled Release Tablet.

Purpose: This study aimed at determining the optimum concentration of hydroxypropyl methylcellulose (HPMC) as hydrogel matrix and citric acid-locust bean gum (CA-LBG) as negative matrix for controlled release tablet formulation. In addition, the study was to determine the effect of CA-LBG and HPMC. CA-LBG accelerates the disintegration of tablets into granules so that the HPMC granule matrix swells immediately and controls drug release. The advantage of this method is that the tablets do not produce large HPMC gel lumps without drug (ghost matrix) but form HPMC gel granules, which can be rapidly degraded after all of the drug is released. Methods : The experiment followed the simplex lattice design to obtain the optimum tablet formula with CA-LBG and HPMC concentrations as optimization factors. Tablet production by the wet granulation method and ketoprofen is the model of the active ingredient. The kinetics of ketoprofen release was studied using several models. Results : Based on the coefficients of each polynomial equation that HPMC and CA-LBG increased the value of angle of repose (29.91:27.87), tap index (18.99:18.77), hardness (13.60:13.32), friability (0.41:0.73), and release of ketoprofen (52.48:99.44). Interaction of HPMC and CA-LBG increased the value of angle of repose (3.25), tap index (5.64), and hardness (2.42). Interaction of HPMC and CA-LBG too decreased the friability value (-1.10) and release of ketoprofen (-26.36). The Higuchi, Korsmeyer-Peppas, and Hixson-Crowell model is the kinetics of eight experimental tablet formulas. Conclusions : The optimum concentrations of HPMC and CA-LBG for controlled release tablets are 32.97 and 17.03%, respectively. HPMC, CA-LBG, and a combination of both affect the physical quality of tablet and tablet mass. CA-LBG is a new excipient candidate that can control drug release from tablets by the matrix disintegration mechanism on the tablet.

Turnover of the extracellular polymeric matrix of granules performing biological phosphate removal

Polyphosphate accumulating organisms (PAOs) are responsible for enhanced biological phosphate removal (EBPR) from wastewater, where they grow embedded in a matrix of extracellular polymeric substances (EPS). EPSs comprise a mixture of biopolymers like polysaccharides or (glyco)proteins. Despite previous studies, little is known about the dynamics of EPS in mixed cultures, and their production by PAOs and potential consumption by flanking microbes. EPSs are biodegradable and have been suggested to be a substrate for other organisms in the community. Studying EPS turnover can help elucidate their biosynthesis and biodegradation cycles. We analyzed the turnover of proteins and polysaccharides in the EPS of an enrichment culture of PAOs relative to the turnover of internal proteins. An anaerobic-aerobic sequencing batch reactor (SBR) simulating EBPR conditions was operated to enrich for PAOs. After achieving a stable culture, carbon source was switched to uniformly 13C-labeled acetate. Samples were collected at the end of each aerobic phase. EPSs were extracted by alkaline treatment. 13C enrichment in proteins and sugars (after hydrolysis of polysaccharides) in the extracted EPS were measured by mass spectrometry. The average turnover rate of sugars and proteins (0.167 and 0.192 d−1 respectively) was higher than the expected value based on the solid removal rate (0.132 d−1), and no significant difference was observed between intracellular and extracellular proteins. This indicates that EPS from the PAO enriched community is not selectively degraded by flanking populations under stable EBPR process conditions. Instead, we observed general decay of biomass, which corresponds to a value of 0.048 d−1.Key Points• Proteins showed a higher turnover rate than carbohydrates.• Turnover of EPS was similar to the turnover of intracellular proteins.• EPS is not preferentially consumed by flanking populations.

Time-Resolved Four-Channel Jones Matrix Measurement of Birefringent Materials Using an Ultrafast Laser.

A method for ultrafast time-resolved four-channel Jones matrix measurement of birefringent materials using an ultrafast laser is investigated. This facilitated the acquisition of a four-channel angular multiplexing hologram in a single shot. The Jones matrix information of a birefringent sample was retrieved from the spatial spectrum of a hologram. The feasibility of this approach was established by measuring the Jones matrix of starch granules in microfluidic chips and the complex amplitude distribution and phase delay distribution of liquid crystal cell at different voltages. Moreover, when the picosecond laser was switched to a femtosecond laser, ultrafast measurements were possible provided that the time interval between two detection pulses was larger than the pulse width.

The Architecture, Nature, and Mystery of Starch Granules. Part 2

AbstractA review with 259 references. Part 2 of a summarized history of investigations into the structures of starch granules is divided into seven sections: the molecules of starches, amylopectin models and starch crystallinity, the granule matrix, blocklet and fibrillar structures, location of amylose and amylopectin, granule models, summary of the architecture of starch granules.

Diffusion of soluble organic substrates in aerobic granular sludge: Effect of molecular weight

Aerobic granular sludge (AGS) is an advanced biofilm-based technology for wastewater treatment. Diffusion of substrates into the granules is a key aspect of this technology. Domestic wastewater contains soluble organic substrates of different sizes that could potentially diffuse into the granules. In this study, the relation between the molecular weight of a substrate and its diffusion coefficient within the granule was studied with model substrates (polyethylene glycols (PEGs) with a molecular weight between 62 and 10 000 Da). The diffusion coefficients of the model substrates within granules from a full-scale installation were measured with the ‘transient uptake of a non-reactive solute’ method. The diffusion coefficients in the granules were not significantly different from the diffusion coefficients in water, at least up to 4000 Da molecular weight. This indicates that these PEGs were not obstructed by the granule matrix. The 10 kDa PEG behaved differently from the lighter PEGs, as it could not penetrate the entire granule. Furthermore, the granule structure was characterized with Environmental Scanning Electron Microscopy (ESEM). The granules displayed an open structure with large macropores and semi-solid regions, which contained microbial cells. The diffusion results suggest that most diffusing molecules were unobstructed in the macropores and barely obstructed in the semi-solid regions. Only the diffusion of the 10 kDa PEG seemed to be hindered by the semi-solid regions, but not by the macropores. Lastly, the apparent molecular weight distribution of domestic wastewater soluble COD was determined with ultrafiltration membranes of 100, 10, and 1 kDa molecular weight cut-off. The influent fractionation revealed that a large part (61–69%) of the influent soluble COD was lighter than 1 kDa. As molecules lighter than 1 kDa diffuse easily, the majority of the influent soluble COD can be considered as diffusible COD. These findings provide new insight into the availability of influent COD for granular sludge.

Electrostatic switch of magnetic anisotropy in the composite with iron-metal granule and barium-titanate matrix

This work investigates electrostatic switch of magnetic anisotropy in the composite with iron-metal granule and barium-titanate matrix theoretically. As the spontaneous polarization is switched downward or upward in barium-titanate matrix, the parallel or perpendicular magnetizing is preferred in iron-metal granule respectively. This demagnetizing anisotropy originates from the long-range electrostatic interaction in matrix body, which induces the inharmonic magnetic moment on granule surface. The effects of position bias and composite size are delicately studied. The cross-section map displays distorted electric polarization in barium-titanate matrix, and demagnetizing energy gradient in iron-metal granule. This work predicts the electrostatic switch of magnetic anisotropy in metal/oxide composite, which would develop the integrated device and functional material.

Mast Cells Heparin — New Information on the Old Component (Review)

Mast cells (MC) are widely distributed throughout the body of animals and humans, mainly in barrier tissues. This review provides new information on the hematopoietic origin of MCs from early erythromyeloid progenitors (EMPs), late EMPs, and definitive hematopoietic stem cells. As well as information on the maturation of MSs and heparin synthesis already in the embryonic period. Many physiological functions of MCs are determined by the properties of heparin, which forms the basis of the matrix of granules, since the heparin molecule is a strong polyanion, capable to forming complexes with many biologically active substances and regulating their properties. In a new hypothesis about the participation of MCs in pathological processes, it is assumed that this is due to the depletion of the heparin pool. In such cases, injections of exogenous heparin can help replenish MCs heparin stores. As a result of the restoration of the physiological functions of MCs and the action of exogenous heparin, the pathological process will be converted into an adaptive one. In clinical practice, unfractionated heparin (UFH) obtained from natural sources and low molecular weight heparin (LMWH) obtained by the biochemical route are used. Most often, UFH and LMWH are used in the clinic only as anticoagulants. The worldwide spread of a disease named COVID-19 in 2020 showed that UFH and LMWH are multifunctional drugs that have saved many people. The pandemic caused by COVID-19 has been an unprecedented social and health emergency worldwide. Depression, anxiety and post-traumatic stress disorder (PTSD) have been reported in populations of many countries. This review provides new information on experimental studies on the successful treatment of pathology with low doses of UFH in modeling PTSD in animals. Consequently, heparin can be considered as a promising multifunctional drug for effective pharmacological correction of comorbid diseases under the influence of extreme factors.

The Alpha-Granule Release Reaction Is Mediated By SNARE-Dependent Solubilization of the Granule Matrix

Within their electron dense granule matrix, alpha-granules package a wide range of proteins important to hemostasis, thrombosis, inflammation, and angiogenesis. During the platelet release reaction, these proteins are secreted in a kinetically diverse manner that is proportional to agonist stimulation. The release reaction is accompanied by a large expansion in granule volume, matrix decondensation, and the solubilization of the included proteins. We have previously posited that some combination of differential protein proximity to granule exit sites and protein solubilization could contribute to the diversity of protein release.Here we have used thrombin stimulation and SNARE knockout mice to test two possible mechanisms for granule decondensation/matrix solubilization. In the first, granule swelling and decondensation precedes fusion with the plasma membrane and is regulated by aquaporin-mediated water influx presumably driving the volume change. In the second, matrix solubilization is plasma membrane fusion dependent with the extracellular influx of water through the fusion pore driving volume change and granule decondensation.In wild-type mouse platelets, we found a precursor-product relationship between the incidence of condensed and decondensed granules with the incidence of decondensed granules peaking at 90 sec post-stimulus (0.1 U/mL thrombin). The subsequent decrease in decondensed granules was due to an increasing incidence of compound granule fusion. By electron tomography, granules were connected to the plasma membrane by “necks” or short “pipes”. The granule membrane remained physically distinct during the entire granule decondensation process. Granule decondensation was marked by the conversion of the granule matrix into a diffuse fibrous structure that decreased progressively in electron density over the 5 min stimulation period. A residual electron-dense core was most obvious at 90 sec post stimulation. At the plasma membrane fused granule neck/pipe, solubilized granule matrix fibers were observed to be extruded extracellularly.Overall, the data suggest a progressive solubilization of granule matrix contents and their accompanying extrusion through the granule neck/pipe. In SNARE knockout mouse platelets, SNARE-selective inhibition of matrix solubilization/granule decondensation was observed. Both qualitatively and quantitatively, knockout of VAMP2/3 had little-to-no effect on 1) alpha-granule fusion with the plasma membrane, 2) granule decondensation, 3) matrix solubilization, or 4) compound granule fusion. In striking contrast, VAMP8 knockout initially produced a substantial inhibition of the incidence of all four steps in the granule releasate reaction while a VAMP2/3/8 knockout almost totally inhibited all four steps. In sum, our data strongly indicate that alpha-granule decondensation and matrix protein solubilization/extrusion are highly dependent on SNARE-mediated granule fusion with the plasma membrane. These data provide no support for the alternative mechanism that regulated aquaporin-dependent water influx mediates granule decondensation prior to granule fusion with the plasma membrane or canalicular system.This work was supported in part by NIH grant R01 HL 119393 to BS, NIH grant R01 HL56652 to SWW, and AHA grant 15PRE2555020 to SJ. DisclosuresNo relevant conflicts of interest to declare.

Use of Drug Release Testing to Evaluate the Retention of Abuse-Deterrent Properties of Polyethylene Oxide Matrix Tablets.

Abuse-deterrent formulations (ADFs) using physical/chemical barrier approaches limit abuse by providing resistance to dosage form manipulation to limit drug extraction or altered release. Standardizing in vitro testing methods to assess the resistance to manipulation presents a number of challenges, including the variation in particle sizes resulting from the use of various tools to alter the tablet matrix (e.g., grinding, chipping, crushing). A prototype, direct-compression ADF using a sintered polyethylene oxide (PEO) matrix containing dextromethorphan, an enantiomeric form of the opioid, levorphanol, was developed to evaluate testing methodologies for retention of abuse-deterrent properties following dosage form tampering. Sintered PEO tablets were manipulated by grinding, and drug content and release were evaluated for the recovered granules. Drug content analysis revealed that higher amounts of drug were contained in the smaller size granules (< 250μm, 190% of the theoretical amount) compared with the larger particles (> 250μm, 55-75% of theoretical amount). Release testing was performed on various size granule fractions (> 850μm, 500-850μm, 250-500μm, and < 250μm) using USP type I (basket), type II (paddle), and type IV (flow-through) apparatus. The USP type I and type II apparatus gave highly variable release results with poor discrimination among the release rates from different size granules. The observed sticking of the hydrated granules to the baskets and paddles, agglomeration of hydrated granules within the baskets/vessels, and ongoing PEO hydration with subsequent gel formation further altered the particle size and impacted the rate of drug release. The use of a flow-through apparatus (USP type IV) resulted in improved discrimination of drug release from different size granules with less variability due to better dispersion of granules (minimal sticking and aggregation). Drug release profiles from the USP type IV apparatus showed that the larger size granules (> 500μm) offered continued resistance to drug release following tablet manipulation, but the smaller size granules (< 500μm) provided rapid drug release that was unhindered by the hydrated granule matrix. Since < 500-μm size particles are preferred for nasal abuse, improved direct-compression ADF formulations should minimize the formation of these smaller-sized particles following tampering to maintain the product's abuse-deterrent features.

Amylose in starch: towards an understanding of biosynthesis, structure and function.

Starch granules are composed of two distinct glucose polymers - amylose and amylopectin. Amylose constitutes 5-35% of most natural starches and has a major influence over starch properties in foods. Its synthesis and storage occurs within the semicrystalline amylopectin matrix of starch granules, this poses a great challenge for biochemical and structural analyses. However, the last two decades have seen vast progress in understanding amylose synthesis, including new insights into the action of GRANULE BOUND STARCH SYNTHASE (GBSS), the major glucosyltransferase that synthesises amylose, and the discovery of PROTEIN TARGETING TO STARCH1 (PTST1) that targets GBSS to starch granules. Advances in analytical techniques have resolved the fine structure of amylose, raising new questions on how structure is determined during biosynthesis. Furthermore, the discovery of wild plants that do not produce amylose revives a long-standing question of why starch granules contain amylose, rather than amylopectin alone. Overall, these findings contribute towards a full understanding of amylose biosynthesis, structure and function that will be essential for future approaches to improve starch quality in crops.

Taurine chloramine selectively regulates neutrophil degranulation through the inhibition of myeloperoxidase and upregulation of lactoferrin.

Taurine is a free amino acid rich in neutrophils, and neutrophils play an important role in the forefront defense against infection. Upon neutrophil activation, taurine reacts with hypochlorous acid (HOCl/OCl-) produced by the myeloperoxidase (MPO) system and gets converted to taurine chloramine (Tau-Cl). Neutrophils have three types of granules, of which the primary granule MPO, secondary granule lactoferrin, and tertiary granule matrix metalloproteinase (MMP)-9 are released into the extracellular space by a process called degranulation. MPO produces hypochlorous acid to kill microorganisms, and the released MPO forms neutrophil extracellular traps (NETs) with released chromatin. Excessive secretion of MPO causes oxidative damage to the surrounding tissues. Lactoferrin exerts antioxidant activity, prevents pro-inflammatory pathway activation, sepsis, and tissue damages, and delays neutrophil apoptosis. Our experimental results show that neutrophils released small amount of granules in an inactive state, and phorbol 12-myristate 13-acetate (PMA) and N-formyl-methionine-leucyl-phenylalanine induced neutrophil degranulation. Tau-Cl inhibited the PMA-induced degranulation of MPO and formation of NETs. While Tau-Cl increased the degranulation of lactoferrin, it had no effect on MMP-9 degranulation. MPO negatively regulated the production of macrophage inflammatory protein (MIP)-2, which stimulates the degranulation and migration of neutrophils. Tau-Cl abrogated MIP-2 expression, suggestive of its inhibitory effect on MPO release. The increase in the intracellular level of MPO may negatively regulates MIP-2 expression, thereby contributing to the further regulation of neutrophil degranulation and migration. Here, we suggest that Tau-Cl selectively inhibits MPO degranulation and stimulates lactoferrin degranulation from neutrophils, thereby protecting inflamed tissues from oxidative damage induced by excessively released MPO.

Design of self-dispersible microsponge containing cyclosporine through wet milling and drop freeze-drying processes to improve dissolution behavior

Cyclosporine (Cyc) is an immunosuppressant used to treat psoriasis and atopic dermatitis and mainly commercialized as a soft capsule due to its poorly water-soluble characteristics. The authors attempted to develop the solid pharmaceutical formulations for oral use (granules, tablet) with improved solubility of Cyc. In this research, a manufacturing method of spherical granules containing nano-sized Cyc particles was newly developed by using the combination between wet milling and drop freeze-drying (DFD) technique. Cyc nanosuspension prepared through wet-milling process was poured dropwise into liquid nitrogen, and the resultant spherical ice grains were freeze-dried to prepare granules with around 300 μm in size. The granules prepared through these sequential processes were identified as porous spherical granules having submicron Cyc particles embedded in water-soluble fiber network structure of additives. When they were placed in aqueous phase, water would immediately penetrate into the matrix of granules through the pores. Subsequently, Cyc particles were spontaneously dispersed into the media as soon as matrix base was dissolved, resulting in the reconstitution of nano-suspension. As a result, the resultant DFD granule, named microsponge, had fast dissolution behavior of more than 80% within 10 min in aqueous phase. The dissolution rate of Cyc from the microsponge strongly depended on the size of embedded Cyc particles, demonstrating that the wet nano-milling must be indispensable process to prepare the microsponge.

Flow cytometric basophil activation tests: Staining of exteriorized basophil granule matrix by fluorescent avidin versus appearance of CD63.

Staining of exteriorized basophil granule matrix by fluorescent avidin might be a reliable technique to monitor basophil degranulation. This study compares the avidin-based technique with the upregulation of CD203c and appearance of CD63 in response to various stimuli. Fourteen individuals responsive to anti-IgE, nine healthy controls, and five birch pollen-allergic patients, and five nonresponders were studied. Activation experiments included anti-IgE, fMLP, interleukin-(IL)-3, and birch pollen allergen. Basophil activation/degranulation was analyzed by flow cytometry and microscopy using anti-CD63, anti-CD203c, and avidin. Stimulation with anti-IgE, fMLP, and relevant allergen results in upregulation of CD203c, CD63 appearance, and an increase in avidin binding. In response to anti-IgE and allergen, upregulation of CD203c peaks within 10 min, CD63 and avidin binding reach a plateau after 10-20 min. CD63 staining leads to a bimodal distribution, avidin staining causes a unimodal shift with a less clear discrimination between degranulating and nondegranulating cells. In response to fMLP, upregulation of CD203c and CD63 and avidin binding are maximal after 2.5 min. Following incubation with anti-IgE and fMLP, percentages of CD203c+ cells are higher than those of CD63+ and avidin+ cells, pointing to a dissociation between activation and degranulation. Percentages of CD63+ cells are systemically higher than those of avidin+ cells. Incubated with IL-3 only upregulates CD203c, while no CD63 or avidin binding is observed. Staining of exteriorized proteoglycans by avidin is a reliable technique to quantify basophil degranulation but offers no added value when compared to traditional assays that use CD63 as a readout.

Subcellular Localization of the TFF Peptides xP1 and xP4 in the Xenopus laevis Gastric/Esophageal Mucosa: Different Secretion Modes Reflecting Diverse Protective Functions.

The TFF peptides xP1 and xP4 from Xenopus laevis are orthologs of TFF1 and TFF2, respectively. xP1 is secreted as a monomer from gastric surface mucous cells and is generally not associated with mucins, whereas xP4 is a typical secretory peptide from esophageal goblet cells, and gastric mucous neck and antral gland cells tightly associated as a lectin with the ortholog of mucin MUC6. Both TFF peptides have diverse protective functions, xP1 as a scavenger for reactive oxygen species preventing oxidative damage and xP4 as a constituent of the water-insoluble adherent inner mucus barrier. Here, we present localization studies using immunofluorescence and immunoelectron microscopy. xP1 is concentrated in dense cores of secretory granules of surface mucous cells, whereas xP4 mixes with MUC6 in esophageal goblet cells. Of note, we observe two different types of goblet cells, which differ in their xP4 synthesis, and this is even visible morphologically at the electron microscopic level. xP4-negative granules are recognized by their halo, which is probably the result of shrinkage during the processing of samples for electron microscopy. Probably, the tight lectin binding of xP4 and MUC6 creates a crosslinked mucous network forming a stabile granule matrix, which prevents shrinkage.

3D ultrastructural analysis of α‐granule, dense granule, mitochondria, and canalicular system arrangement in resting human platelets

BackgroundState‐of‐the‐art 3‐dimensional (3D) electron microscopy approaches provide a new standard for the visualization of human platelet ultrastructure. Application of these approaches to platelets rapidly fixed prior to purification to minimize activation should provide new insights into resting platelet ultrastructure. ObjectivesOur goal was to determine the 3D organization of α‐granules, dense granules, mitochondria, and canalicular system in resting human platelets and map their spatial relationships. MethodsWe used serial block face–scanning electron microscopy images to render the 3D ultrastructure of α‐granules, dense granules, mitochondria, canalicular system, and plasma membrane for 30 human platelets, 10 each from 3 donors. α‐Granule compositional data were assessed by sequential, serial section cryo‐immunogold electron microscopy and by immunofluorescence (structured illumination microscopy). Results and Conclusionsα‐Granule number correlated linearly with platelet size, while dense granule and mitochondria number had little correlation with platelet size. For all subcellular compartments, individual organelle parameters varied considerably and organelle volume fraction had little correlation with platelet size. Three‐dimensional data from 30 platelets indicated only limited spatial intermixing of the different organelle classes. Interestingly, almost 70% of α‐granules came within ≤35 nm of each other, a distance associated in other cell systems with protein‐mediated contact sites. Size and shape analysis of the 1488 α‐granules analyzed revealed no more variation than that expected for a Gaussian distribution. Protein distribution data indicated that all α‐granules likely contained the same major set of proteins, albeit at varying amounts and varying distribution within the granule matrix.

Basophil Activation Techniques: Staining of Exteriorized Granule Matrix.

The basis of traditional flow cytometry allergy diagnosis is measurement of the expression of basophilic surface activation and/or degranulation markers. Basophils, upon encounter with a specific allergen that cross-links surface FcRI-bound IgE antibodies, not only secrete and release quantifiable bioactive mediators but also upregulate the expression of different markers (e.g., CD63, CD203c) which can be detected by multicolor flow cytometry using specific monoclonal antibodies. Here, we describe a novel technique that relies upon the staining of exteriorized anionic proteoglycans from a basophil granule matrix by cationic fluorescent avidin probes.

Adrenergic chromaffin cells are adrenergic even in the absence of epinephrine.

Adrenal chromaffin cells release epinephrine (EPI) and norepinephrine (NE) into the bloodstream as part of the homeostatic response to situations like stress. Here we utilized EPI-deficient mice generated by knocking out (KO) the phenylethanolamine N-methyltransferase (Pnmt) gene. These Pnmt-KO mice were bred to homozygosis but displayed no major phenotype. The lack of EPI was partially compensated by an increase in NE, suggesting that EPI storage was optimized in adrenergic cells. Electron microscopy showed that despite the lack of EPI, chromaffin granules retain their shape and general appearance. This indicate that granules from adrenergic or noradrenergic cells preserve their characteristics even though they contain only NE. Acute insulin injection largely reduced the EPI content in wild-type animals, with a minimal reduction in NE, whereas there was only a partial reduction in NE content in Pnmt-KO mice. The analysis of exocytosis by amperometry revealed a reduction in the quantum size (-30%) and Imax (-21%) of granules in KO cells relative to the wild-type granules, indicating a lower affinity of NE for the granule matrix of adrenergic cells. As amperometry cannot distinguish between adrenergic or noradrenergic cells, it would suggest even a larger reduction in the affinity for the matrix. Therefore, our results demonstrate that adrenergic cells retain their structural characteristics despite the almost complete absence of EPI. Furthermore, the chromaffin granule matrix from adrenergic cells is optimized to accumulate EPI, with NE being a poor substitute. Open Science: This manuscript was awarded with the Open Materials Badge For more information see: https://cos.io/our-services/open-science-badges/.

Electric modulation of magnetic anisotropy on the granule/matrix interface of a permalloy/PZT composite

In this work, the electric modulation of magnetic anisotropy is investigated on a granule/matrix interface of a Py/PZT composite. Outside the Py/PZT interface, the electric polarization is derived through the Thomas-Fermi model and mean field approximation. Inside the Py/PZT interface, the magnetizing energy is derived through the spin-split model and spherical shell approximation. As the Py volume fraction varies from 0.0% to 0.8%, the electric polarization evolves from radiationlike to vortexlike distribution, while the magnetizing energy evolves from symmetric-type to asymmetric-type distribution. Under downward and upward polarization, parallel and perpendicular magnetization are preferred, respectively. As the granule diameter or matrix thickness is varied, the downward polarization induces unstable parallel magnetic anisotropy, while the upward polarization induces stable perpendicular magnetic anisotropy. This work is beneficial for achieving electrostatic manipulation of a magnetic vortex.