Increase In Cell Volume Research Articles

Cell volume controlled by LRRC8A-formed volume-regulated anion channels fine-tunes T cell activation and function

Biosynthesis drives the cell volume increase during T cell activation. However, the contribution of cell volume regulation in TCR signaling during T lymphoblast formation and its underlying mechanisms remain unclear. Here we show that cell volume regulation is required for optimal T cell activation. Inhibition of VRACs (volume-regulated anion channels) and deletion of leucine-rich repeat-containing protein 8A (LRRC8A) channel components impair T cell activation and function, particularly under weak TCR stimulation. Additionally, LRRC8A has distinct influences on mRNA transcriptional profiles, indicating the prominent effects of cell volume regulation for T cell functions. Moreover, cell volume regulation via LRRC8A controls T cell-mediated antiviral immunity and shapes the TCR repertoire in the thymus. Mechanistically, LRRC8A governs stringent cell volume increase via regulated volume decrease (RVD) during T cell blast formation to keep the TCR signaling molecules at an adequate density. Together, our results show a further layer of T cell activation regulation that LRRC8A functions as a cell volume controlling “valve” to facilitate T cell activation.

Migration pathway and solidification mechanism of heavy metal Pb during the conversion of municipal solid waste incineration fly ash into ettringite and simultaneously purification of chloride salts solution process

The solidification/stabilization of heavy metals and valuable component recovery from municipal solid waste incineration (MSWI) fly ash are of great significance for its safe disposal. In this study, MSWI fly ash was transformed into a new solid phase mainly composed of ettringite, achieving the solidification of excessive heavy metal Pb while obtaining a mixed solution of sodium chloride and potassium chloride with extremely low impurity content, which can be recovered by evaporation-crystallization respectively. The solidification mechanism of heavy metal Pb by ettringite was investigated through a combination of DFT calculations and experiments. The results indicate that a high conversion rate of calcium ions (99.68%), separation rate of chloride (95.99%), and conversion rate of heavy metal Pb (99.42%) can be achieved by controlling the ions ratio of the MSWI fly ash reaction system to n(Ca2+):n(Al3+):n(SO42−) = 6:2:3. DFT calculations show that the reaction pathway of the formation of a vacancy-Pb entering the vacancy at the Ca-2 site of ettringite is more likely to occur. The substitution of heavy metal Pb at the Ca-2 site leads to an increase in the unit cell volume, redistribution of charges, and a decrease in the thermal stability of the ettringite. The solidified body of ettringite presents a promising potential for application in cement-based materials due to its negligible risk of heavy metals leaching and low chloride content.

Microfluidic Assessment of T Cell Deformability and Capillary Network Occlusion

Introduction: Adoptive T cell therapies offer a new frontier of cancer treatment that disrupts the conventional chemotherapy paradigm. Naïve T cells can be genetically modified to directly target cancerous cells and have proven to be aggressively effective in fighting cancers resistant to chemotherapies. A major challenge that adoptive T cell therapies face is successfully delivering the cell products to the location of the target cells, which is particularly challenging in the case of solid tumors. A complete characterization of the biomechanical properties of T cell products would help researchers gain insight into the capacity of these engineered cells to navigate and extravasate through vasculature and tumor microenvironments. Previous studies have found that T cell volume, cortical tension, and dynamic resistance increase with activation (Waugh et al. Front Bioeng Biotechnol. 2023). A simple and reproducible method to easily quantify and assess such cellular properties has yet to be established. Presently, we describe a microfluidic assay for the rapid and robust characterization of the mechanical changes of T cells upon activation. Our assay models the microcapillaries through a gradient of micropillar arrays, which allows for the evaluation of T cells perfused through the network. The spacing between pillars is 12 µm at the first array, similar to small arterioles, and incrementally decreases to 3 µm spacing in the last array, mimicking small capillaries ( Figure 1A). Trafficking of adoptive T cell therapies through the microvasculature networks of this scale into their target tissues represents a persistent and major challenge facing these therapies (Marofi et al. Stem Cell Res. Ther. 2021). Methods: The microfluidic devices were fabricated by casting polydimethylsiloxane (PDMS) on a silicone wafer fabricated through photolithographic protocols. Devices contain arrays of pillars measuring 20 µm x 10 µm x 12 µm with gradient spacing beginning at 12 µm at the inlet and 3 µm at the outlet. Jurkat T cells were cultured in RPMI 1640 medium with 10% fetal bovine serum and used in a naïve state or activated via antibody stimulation of CD3 and CD28. T cells were then suspended in growth media at 1x10 6 cells/mL. Microchannels were wetted and cleaned with 100% ethanol perfused at 10 µL/min for 15 minutes followed by cell culture media at 10 µL/min for 15 minutes to block the non-specific binding sites on the PDMS and to create a biocompatible environment for the cell sample. The devices were connected to a digital pneumatic pressure-based flow pump system. The cell sample was perfused at 100 mBar for 7 minutes and a subsequent wash process with growth media at 100 mBar for 7 minutes was performed to flush non-occluded cells. Upon completion of the experiment, the channel was scanned using Phase and DAPI filters with an Olympus IX83 inverted motorized microscope, and occluded T cells were quantified using ImageJ. Results: Our assay showed distinct levels of T cell occlusion upon activation through CD3 and CD28 stimulation. Naïve T cells showed lower levels of occlusion in each of the first five arrays compared to activated T cells, while both groups showed high levels of occlusion in the final 3 µm array. Activated T cells showed approximately three times the amount of occlusion in the second through fifth arrays. To assess overall occlusion, we use the Occlusion Index (OI), which considers the density of pillars and the number of cells caught in each array. We found that activated T cells had a significantly higher OI when compared to non-activated T cell samples (p < 0.05, unpaired t-test). Naïve T cells had an OI mean of 24.4 ± 5.0 while activated T cells had a mean of 42.5 ± 5.6 ( Figure 1B). Conclusions: Our results show that there is a significant increase in resistance of activated T cells through a microvasculature-modeled environment compared to their naïve counterparts. As adoptive T cell therapies increase in popularity, a complete understanding of the biomechanical properties of these cell products will be necessary for effective design. Our microfluidic assay mimics the narrowing channels of the microvasculature and permits the study of how naïve and engineered T cells travel through these mechanically challenging spaces.

The interaction between Co and Mn ions on the magnetic frustration and the inducement of the double-exchange mechanism in hole-doped La0.6Dy0.1Ca0.3Co1-xMnxO3 (x = 0–1.0) cobaltite

This study investigates the interaction between Co and Mn ions on spin state behaviour and magnetic frustration in hole-doped La0.6Dy0.1Ca0.3Co1-xMnxO3 (x = 0–1.0) cobaltite. It aims to understand the inducement of the double-exchange (DE) mechanism in this system. The samples were synthesised using the conventional solid-state synthesis method, and their crystal structure and magnetic properties were analysed. Rietveld refinement of X-ray diffraction data confirmed that La0.6Dy0.1Ca0.3Co1-xO3 (x = 0.0 and 0.2) samples had rhombohedral crystals structure with R c − 3 space group. An orthorhombic (Pbnm) perovskite structure was observed for the La0.6Dy0.1Ca0.3Co1-xMnxO3 (x = 0.4 –1.0) accompanied by increasing cell volume in the samples as the substitution level of Mn increases. Temperature dependence of resistivity ρ(T) shows semiconducting behaviour in the whole temperature and composition range of x = 0.0–0.8. However, further substitution with x = 0.9 and x = 1.0 give remarkable induced MI behaviour where the MI transition temperature (TMI) increased from 75 K and 132 K, respectively. The result suggests that Mn ions play an important role in the magnetic properties of the cobaltite, and the system can be tuned by adjusting the Mn concentration.

Synthesis and tailoring the structural and magnetic characteristics of Zn–Zr substituted Sr-hexaferrite targeting diverse applications

SrZnxZrxFe12-2xO19 (x varying within 0.1–0.4) samples were prepared successfully via solid state route. Their structural characteristics (along with microstructural and magnetic) have been discussed. Rietveld refinement established the phase purity for the samples x ≤ 0.3 (goodness-of-fit <1.15) whereas the presence of ZnFe2O4 and SrZrO3 impure phases was observed in x = 0.4 sample. The three-phase model resulted in decreasing χ2 values from 1.21 to 1.05 for x = 0.4 sample. The XRD findings also reveal an increasing cell volume from 690.675 Å3 (x = 0.1) to 693.096 Å3 (x = 0.3) and a decreasing porosity from 33% to 30% on increasing ˋx’. The average grain size increases from 0.83 μm to 1.04 μm according to FESEM micrographs with increasing ˋx’. The TEM measurements reveal the presence of rod like particles (in addition to random shaped particles) in x = 0.1–0.3 samples. M v/s H studies reveal, and increase in Ms from 90.26 emu/g (for x = 0.0) to 91.41 emu/g (for x = 0.1) and a decreasing trend afterwards to 87.90 emu/g (at x = 0.3). Hc value continuously decreases from 5032 Oe (for x = 0.0) to 1903 Oe (for x = 0.4). Low temperature M − H and M-T measurements coupled with room temperature M − H measurements reveal the absence of superparamagnetic behaviour. The magnetic data suggest that all the samples possess hard ferrite characteristics and could be useful for microwave absorbers, permanent magnets as well as high-density recording media applications.

Comparative Evaluation of the Effect of Copper Oxide and Copper Sulfate Nanoparticles on Structural and Functional Characteristics of Thalassiosira weissflogii under Conditions of Enrichment Cultivation // Russian Journal of Plant Physiology.

The effect of copper oxide nanoparticles (500, 1000, 2000 μg/L) and copper ions (37.5, 75, 150 μg/L) on the morphological, structural-functional, and fluorescent parameters of diatom microalgae Thalassiosira weissflogii under conditions of long-term cultivation was studied. It was shown that copper in ionic form is more toxic for this microalgae species than in the form of a nanooxide. The nature of the effect of copper in ionic and nanoform on cells Thalassiosira weissflogii has both similarities and significant differences. The difference in the effect of the studied toxicants on the growth of algae and the performance of photosynthetic apparatus was revealed. The addition of copper ions into the cultivation medium led to long lag phase during the initial stage of the experiment, followed by the restoration of growth on days 3–6 of exposure. An increase in the concentration of copper oxide nanoparticles in the medium caused inhibition of algae growth without a pronounced lag phase. With an increase in the concentration of Cu2+ in the culture medium, a decrease in the quantum efficiency of light energy utilization by the PS II photosynthetic complex and the maximum relative electron transport rate were observed, while copper oxide nanoparticles had an insignificant effect on the efficiency of the photosynthetic apparatus ofThalassiosira weissflogii. With an increase in the concentration of copper, both in the ionic form and in the form of nanooxide, increase in cell volume, changes of cell shape and granularity, an increase in the production of reactive oxygen species, suppression of enzymatic activity and a decrease in autofluorescence values of individual cells in the red region of the spectrum were observed.

Long-Term Tests and Advanced Post-Test Characterizations of the Oxygen Electrode in Solid Oxide Electrolysis Cells

Solid Oxide cells (SOCs) are promising high-temperature electrochemical energy-conversion devices, which enable a fossil-free sustainable development. Nevertheless, performance degradation is still a bottleneck for the large-scale commercialization. The most commonly employed material for the air electrode is La1-xSrxCoy-1FeyO3-δ. The chemical decomposition of this material is known to considerably impact the cell performance [1,2].The studied cells are composed of a La0.6Sr0.4Co0.2Fe0.8O3 -δ (LSCF) current collecting layer (CCL) and a LSCF-Ce0.8Gd0.2O2 -δ (LSCF-GDC) composite for the air electrode, GDC for the barrier layer, (Y2O3)0.08(ZrO2)0.92 (YSZ) for the electrolyte and Ni-YSZ for the functional layer and the support layer of the fuel electrode. The present study aims to investigate the degradation occurring in the air electrode of a complete cell aged at 750°C for 2000 h in electrolysis mode. The cell degradation is assessed by electrochemical measurements, such as polarization curves and electrochemical impedance spectroscopy (EIS), and post-mortem characterizations of the air electrode using high resolution multimodal chemical imaging based on synchrotron X-ray diffraction (µ-XRD) in Paul Scherrer Institut (PSI, microXAS), complemented by X-ray photoelectron spectroscopy (XPS).The electrochemical characterizations performed at the beginning of the test and after ageing showed a decrease in the cell performance. Notably, a significant evolution at the high frequency region was observed in the impedance spectrum. However, the medium frequency region of the EIS, mainly ascribed to the air electrode using a physically-based multiscale model [3], did not show any particular evolution. Post-mortem characterizations using synchrotron µ-XRD technique showed an inter-diffusion layer (IDL) in between the GDC and YSZ layers, for both pristine and aged samples (Fig. 1). In addition, a slight increase in the LSCF unit cell volume was observed after ageing. Nevertheless, XPS results did not highlight any significant evolution in the Sr segregation after operation. According to the impedance spectra and the post-mortem analyses, the ageing of the air electrode seems to have a limited impact on the cell performance loss in these operating conditions.

Negative magnetization, shielding current effect and divalent manganese in CaMn1-xTaxO3 manganites

Crystal and electronic structures, and magnetic properties of polycrystalline tantalum substituted manganites CaMn1-xTaxO3 (x = 0.00, 0.03, 0.06, 0.09 and 0.12) were studied by x-ray diffraction, x-ray absorption near edge spectroscopy (XANES) at Mn K-edge, and by magnetization measurements. Large changes of cell volume and magnetic transition temperature, in addition to shift of Mn K-edge spectra and change of shape of XANES spectra, indicate the existence of Mn3+ as well as Mn2+ species induced by the substitution of Mn4+ by Ta5+. Cell parameters and cell volume increase with increasing x because the Mn3+, Mn2+ and Ta5+ ions are larger that substituted Mn4+ ion. According to XANES results, at least the x = 0.00 sample is oxygen deficient. The negative magnetization was observed in the CaMnO3-δ sample, and a possible explanation of the phenomenon is given considering two canted (almost antiferro)magnetic sublattices and a shielding current, associated with the itinerant eg electrons, induced by the oxygen vacancies.

Enhanced humidity sensing properties of interstitial B-doped TiO2 nanofibers

This paper investigates the ability of boron (B) as a dopant in TiO2 nanofibers for use in humidity sensing. B-doped TiO2 nanofibers are synthesized through tuning molar ratio of B/Ti using a facile electrospinning technique. The influences of B content on the phase transition, specific surface area, morphology, and surface valence of TiO2 nanofibers are studied by employing XRD, BET, SEM, and XPS characterization tests. The doping mode and humidity sensing performances for B doping TiO2 nanofibers are also performed in detail. The results show that B is successfully incorporated into the TiO2 lattice using interstitial mode, inducing the increase in cell volume and specific surface area, decreasing grain size. Compared to pristine TiO2 nanofibers, interstitial B doping generates oxygen vacancies and increases the Ti3+ concentration, resulting in an increase in humidity sensitivity. The B-doped TiO2 nanofibers based on the optimum B/Ti molar ratios of 1:4 exhibit high sensitivity, excellent linearity, narrow hysteresis, quick response and recovery time as well as favorable repeatability and stability, which are promising humidity sensing materials. The sensing mechanism is systematically investigated using electrochemical impedance spectroscopy combined with equivalent circuits.

Pendidikan Kesehatan Yang Service Execellent Tentang Edukasi Pencegahan Anemia Pada Ibu Hamil Masa Pandemi Covid – 19 Di Desa Bangun Rejo Kecamatan Tanjung Morawa Kabupaten Deli Serang Tahun 2023

Pregnant women are prone to anemia, because during pregnancy, especially at the end of pregnancy, the process of hemodilution occurs. This process is due to the increase in blood plasma volume in the body which is not proportional to the increase in red blood cell volume, resulting in a decrease in hemoglobin levels in the blood (Ali, 2020). A decrease in hemoglobin levels during pregnancy will cause a decrease in oxygen transport to the body and result in anemia (Percy, et al., 2017). Anemia during pregnancy has long-term and short-term impacts. In the short term, a fetus with an anemic mother in the first trimester is at risk of small for gestational age (SGA) and fetal distress. In Trimester II, the fetus is at risk for macrosomia (Sun et al., 2021), and in Trimester III in the long term it will have an impact on neurocognitive in childhood. Long-term effects include autism, schizophrenia, brain structural abnormalities, impaired thinking memory, and delays in responding to things (Georgieff, 2020; Malinowski et al., 2021). The impact of anemia on mothers during pregnancy in the short term includes infectious shock during inpartum and postpartum (Getahun, et al., 2017), cardiac decompensation (Stephen et al., 2018), and postpartum hemorrhage (Getahun, et al., 2017). In the long term, postpartum hemorrhage leads to death. Meanwhile, postpartum hemorrhage is the first cause of high maternal mortality rates (MMR) in Indonesia in 2020.

Impact of copper oxide nanoparticles on the physiology of different microalgal species

Sublethal concentrations of CuO NPs were added to the medium in the amounts of 3000, 2500, 1000, and 400μg L−1, respectively, to determine the main trends of changes in the morpho — physiological, biochemical and structural indicators of the microalgae Dunaliella salina (Teod.), Isochrysis galbana Parke, 1949; Thalassiosira weissflogii (Grunow) G.A. Fryxell & Hasle, 1977; and Prorocentrum cordatum (Ostenfeld) Dodge, 1975. Nearly every aspect of algae physiology is impacted by NPs, which also cause changes in the integrity of cell wall, an increase in cell volume, and a rise in the number of dead or inactive cells in culture. Reactive oxygen species production rises, metabolic activity of cells falls, mitochondrial membranes depolarize. The four studied species — D. salina, I. galbana, Th. weissflogii and P. cordatum — are arranged in a row, starting with the most resistant to the effects of NPs CuO. The 2% release of Cu2+ copper ions from CuO NPs is not the main cause of the harmful effects of NPs on cells. The mechanical action of CuO NPs, which damages cell membranes and aggregates NPs on the algae’s surface, is primarily responsible for their inhibitory effect on algae. P. cordatum and Th. weissflogii, which have dense shells in comparison to D. salina and I. galbana with ultrathin cell membranes, did not produce cells that were more resilient to the effects of CuO NPs. The photosynthetic system of the tested algae species exhibited high functional tolerance to the impacts of copper oxide nanoparticles. Fluorescent measures (Fv/Fm, rETR) can be used to determine a pollutant’s capacity to obliterate microalgae. It is shown that there is a connection between the unrestrained increase in CuO NPs concentration in water and the potential harm to the primary production of aquatic ecosystems.

Interplay between Kondo and magnetic interactions in Pr0.75Gd0.25ScGeH

Combined experimental and density functional theory (DFT) study of Pr0.75Gd0.25ScGe and its hydride (Pr0.75Gd0.25ScGeH) reveals intricacies of composition-structure-property relationships in those distinctly layered compounds. Hydrogenation of the intermetallic parent, crystalizing in a tetragonal CeScSi-type structure, leads to an anisotropic volume expansion, that is, a(=b) lattice parameter decreases while the lattice expands along the c direction, yielding a net increase of cell volume. DFT calculations predict an antiparallel coupling of localized Gd and Pr magnetic moments in both materials at the ground state. While experiments corroborate this for the parent compound, there is no conclusive experimental proof for the hydride, where Pr moments do not order down to 3 K. DFT results also reveal that rare-earth – hydrogen interactions reduce spin-polarization of the Pr and Gd 5d and Sc 3d states at the Fermi energy, disrupt indirect exchange interactions mediated by conduction electrons, dramatically reduce the magnetic ordering temperature, and open a pseudo-gap in the majority-spin channel. Both experiments and theory show evidence of Kondo-like behavior in the hydride in the absence of an applied magnetic field, whereas increasing the field promotes magnetic ordering and suppresses Kondo-like behavior.

Structural, dielectric, and morphological properties of (1-x)Ba0.65Sr0.35TiO3-xBi(Mg2/3Nb1/3)O3

Compared to other electrical energy storage devices, dielectric capacitors provide advantages like high power density, fast charge and discharge times, thermal stability, excellent mechanical strength, and a long cycling lifetime. Amongst the various dielectric materials, relaxor ferroelectric materials offer low remanent polarization and high energy efficiency. Previous research has shown that (i) doping Bi3+ ions into perovskite material can achieve improved results because its valence electronic configuration is close to that of Pb2+ and its ionic radius is also comparable to that of Ba2+, and (ii) introducing complex ions at the B-site can reduce the long-range ferroelectric order and result in the occurrence of polar nano regions.The present work aims at (i) incorporating both these strategies for the synthesis of the dielectric ceramic material and (ii) studying the structural, morphological, and dielectric properties of the prepared material. We have successfully synthesized (1-x) Ba0.65Sr0.35TiO3 – x BiMg2/3Nb1/3O3 with the help of a conventional solid-state reaction technique. The XRD analysis demonstrates the formation of cubic perovskite structure with space group Pm3m. The diffraction peaks shift towards lower 2θ angles with an increasing concentration of BMN, indicating a regular increase in unit cell volumes owing to the substitution of the smaller Ti4+ ions with bigger Mg2+ and Nb5+ ions. FESEM images illustrate the development of a homogeneous and dense microstructure. Element mapping analysis confirms the uniform distribution of all the elements within the prepared sample. From the dielectric measurements, we found that with the increase in doping, the dielectric peak broadens, and the frequency dispersion increases, indicating a rise in the relaxor behavior, which may be attributed to the increase in cation disorder due to the substitution of Bi3+ and [Mg2/3Nb1/3]4+ at the A- and B-site, respectively. The excellent dielectric properties indicate that (1-x)BST-xBMN is a promising ceramic material for use as a dielectric in capacitors for advanced pulsed power applications and consumer electronic devices.

Activation of CWI pathway through high hydrostatic pressure, enhancing glycerol efflux via the aquaglyceroporin Fps1 in Saccharomyces cerevisiae.

The fungal cell wall is the initial barrier for the fungi against diverse external stresses, such as osmolarity changes, harmful drugs, and mechanical injuries. This study explores the roles of osmoregulation and the cell-wall integrity (CWI) pathway in response to high hydrostatic pressure in the yeast Saccharomyces cerevisiae. We demonstrate the roles of the transmembrane mechanosensor Wsc1 and aquaglyceroporin Fps1 in a general mechanism to maintain cell growth under high-pressure regimes. The promotion of water influx into cells at 25 MPa, as evident by an increase in cell volume and a loss of the plasma membrane eisosome structure, activates the CWI pathway through the function of Wsc1. Phosphorylation of Slt2, the downstream mitogen-activated protein kinase, was increased at 25 MPa. Glycerol efflux increases via Fps1 phosphorylation, which is initiated by downstream components of the CWI pathway, and contributes to the reduction in intracellular osmolarity under high pressure. The elucidation of the mechanisms underlying adaptation to high pressure through the well-established CWI pathway could potentially translate to mammalian cells and provide novel insights into cellular mechanosensation.

SLC26A11 Inhibition Reduces Oncotic Neuronal Death and Attenuates Stroke Reperfusion Injury

Neuronal swelling is a pathological feature of stroke which contributes to the formation of cytotoxic edema. Under hypoxic condition, aberrant accumulation of sodium and chloride ions inside neurons increases osmotic pressure, leading to cell volume increase. Sodium entry pathway in neurons has been studied extensively. Here, we determine whether SLC26A11 is the major chloride entry pathway under hypoxia and could be the target for protection against ischemic stroke. In this study, electrophysiological properties of chloride current in primary cultured neurons were characterized using low chloride solution, 4,4′-diisothiocyano-2,2′-stilbenedisulfonic acid, and SLC26A11-specific siRNA under physiological conditions or ATP-depleted conditions. In vivo effect of SLC26A11 was evaluated on a rat stroke reperfusion model. We found that SLC26A11 mRNA in primary cultured neurons was upregulated as early as 6 h after oxygen glucose deprivation, and later, the protein level was elevated accordingly. Blockade of SLC26A11 activity could reduce chloride entry and attenuate hypoxia-induced neuronal swelling. In the animal stroke model, SLC26A11 upregulation was mainly located in surviving neurons close to the infarct core. SLC26A11 inhibition ameliorates infarct formation and improves functional recovery. These findings demonstrate that SLC26A11 is a major pathway for chloride entry in stroke, contributing to neuronal swelling. Inhibition of SLC26A11 could be a novel therapeutic strategy for stroke.

A comparative study of structural, magnetic and catalytic properties of half doped nanocrystalline La0.5A0.5Mn0.5Fe0.5O3 (A = Ca, Sr) perovskite oxides: Highly efficient and versatile candidates for enhanced oxidative degradation of hazardous organic dyes at ambient conditions

This work presents a systematic study of half doped nanocrystalline La0.5A0.5Mn0.5Fe0.5O3 (A = Ca, Sr) perovskite oxides to examine the effect of A-site cation radius on structural, magnetic and catalytic properties via different characterization techniques. Rietveld refinements of powder X-ray diffraction data confirmed the orthorhombic symmetry for both the samples with Pbnm space group. The results show an increase in lattice parameters and unit cell volume with doping of larger A cation. The BET surface area for Ca and Sr-doped samples has been found to be 32.3 m2/g and 33.8 m2/g respectively. The magnetic properties of nano structured samples show magnetic inhomogeneity due to coexistence of ferromagnetic and antiferromagnetic interactions. The magnetization has enhanced in Sr-doped sample which may be associated with increase in double exchange interactions between mixed valence manganese ions through oxygen. Moreover, the synthesized nano samples have been employed to catalytic degradation of rhodamine B dye as model pollutant under normal atmospheric conditions and it has been found that Sr-doped sample has shown better catalytic dye degradation than Ca-doped (99% degradation in 25 min) due to the presence of greater number of Mn3+/Mn4+ redox couples as determined by iodometric titration. Additionally, methylene blue and methyl orange dyes were also tested for catalytic degradation by more active Sr-doped catalyst in order to check its versability.

Structural and optical properties of gadolinium doped-magnetite nano-crystal for photocatalytic application

Doped ferrite materials offer a combination of enhanced magnetic properties, multifunctionality, higher Curie temperature, biocompatibility, and potential energy applications. Their unique characteristics make them appealing for research in diverse fields, including materials science, electronics, biomedical engineering, and energy technology. In present work, Gadolinium-doped magnetite samples are synthesized following the co-precipitation method. The effects of doping on the structural and optical properties of Fe3O4 are studied. Structural parameters of the samples such as cell parameters, cell volume crystalline size, x-ray density, and average micro-strain are calculated from the analysis of x-ray diffraction (XRD) data via Rietveld refinement method. An increase in crystalline size and cell volume is observed while a reduction in micro-strain is observed with increase in doping concentration. The particle size estimated from FE-SEM data ranges from 9 to 16 nm and is in good agreement with XRD data and confirms the formation of nanoscopic phase of the particles. The presence of characteristic peaks concerned with tetrahedral and octahedral site vibrations in the Fourier transform infrared spectroscopy data approve the formation of inverse spinel structure. The distribution of Gd in the samples is determined with Energy dispersive x-ray analysis. The optical studies show that the direct and indirect band gaps decrease from 4.07 to 3.95 eV and 3.79–3.65 eV, respectively. These values of band gap are indicated the potential use of the synthesized nanoparticles for photocatalytic application.

Crystallite size reduction of Cr doped Al2O3 materials via optimized high-energy ball milling method

α-Al2O3 based compounds have large crystals and it is very difficult to reduce the crystallite size because they are very stable and hard. One way of reducing the crystallite size of the materials is by using high-energy ball milling method. Pure and single-phase micron-sized α-Al2−xCrxO3 (x = 0.1, 0.2, 0.3) materials were successfully obtained via self-propagating combustion method. These materials were then subjected to a simple milling process from their microcrystalline powders. Comparisons between the micron-sized and milled samples in terms of their phase, structure, morphology and crystallite size were discussed. The XRD results reveal that all the milled samples were pure with no impurity or other phases present. Structural parameters are extracted via the Rietveld method, revealing that the cell constant, a, of the milled samples is higher than that of the micron-sized materials by 0.09 % to 0.11 %, resulting in a 0.28 % to 0.39 % increase in cell volume. FESEM results show a gradual decrease in crystallite size with increased milling time. Notably, the method successfully reduces the crystallite size without changing the phase of the materials and preserving the stoichiometry of the Al2−xCrxO3 materials which may offer improved properties in various applications.

Early Endothelial Signaling Transduction in Developing Lung Edema.

The lung promptly responds to edemagenic conditions through functional adaptations that contrast the increase in microvascular filtration. This review presents evidence for early signaling transduction by endothelial lung cells in two experimental animal models of edema, hypoxia exposure, and fluid overload (hydraulic edema). The potential role of specialized sites of the plasma membranes considered mobile signaling platforms, referred to as membrane rafts, that include caveolae and lipid rafts, is presented. The hypothesis is put forward that early changes in the lipid composition of the bilayer of the plasma membrane might trigger the signal transduction process when facing changes in the pericellular microenvironment caused by edema. Evidence is provided that for an increase in the extravascular lung water volume not exceeding 10%, changes in the composition of the plasma membrane of endothelial cells are evoked in response to mechanical stimuli from the interstitial compartment as well as chemical stimuli relating with changes in the concentration of the disassembled portions of structural macromolecules. In hypoxia, thinning of endothelial cells, a decrease in caveolae and AQP-1, and an increase in lipid rafts are observed. The interpretation of this response is that it favors oxygen diffusion and hinder trans-cellular water fluxes. In hydraulic edema, which generates greater capillary water leakages, an increase in cell volume and opposite changes in membrane rafts were observed; further, the remarkable increase in caveolae suggests a potential abluminal-luminal vesicular-dependent fluid reabsorption.

Synergetic optimization of p-type Ba2+ substitution and carbon nanotubes enwrapping in Na3V2(PO4)3: A superior cathode with high electrochemical and safety performance for half and full cells

Na3V2(PO4)3 (NVP) has been deemed as a promising cathode because of high capacity and good stability. Nevertheless, poor intrinsic conductivity seriously limits its further application. Herein, partial Ba2+ substitution on V3+ site is introduced to modify NVP in terms of increasing cell volume due to larger ionic radius of Ba2+ and generating beneficial hole carriers derived from p-type doping. The expanded crystal channels efficiently facilitate the Na + migration and the hole carriers are beneficial for transfer charge to improve electronic conductivity. Ba2+ doping further enhances the structural stability due to the pillar effect, which has been proved by DSC measurement. The increase of exothermic peak temperature and decrease of heat release rate demonstrates the excellent thermal stability of NVBa0.07P@CNTs. Moreover, disordered carbon layer and enwrapped CNTs construct an effective network to provide abundant routes for electronic transportation. Notably, the optimized NVBa0.07P@CNTs delivers superior electrochemical performance in both half and full cells. It releases a capacity of 117.23 mA h g−1 at 0.1C and submits a capacity of 101.99 mA h g−1 with retention of 80% at 15 C over 2000 cycles. Even at 50 C, it still delivers a high value of 78.33 mA h g−1.